Aggregator

WW 595 TORNADO FL GA CW 042355Z - 051000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 595 NWS Storm Prediction Center Norman OK 755 PM EDT Sun Aug 4 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and Northern Florida Southern Georgia Coastal Waters * Effective this Sunday night and Monday morning from 755 PM until 600 AM EDT. * Primary threats include... A few tornadoes possible Isolated damaging wind gusts to 65 mph possible SUMMARY...Convective bands associated with Debby will continue to pose a risk for embedded supercells and a tornado risk. The environment favorable for tornadoes will gradually shift northward this evening into the overnight hours in conjunction with the northward movement of Debby. The tornado watch area is approximately along and 80 statute miles east and west of a line from 35 miles northeast of Valdosta GA to 35 miles southwest of Avon Park FL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && OTHER WATCH INFORMATION...CONTINUE...WW 594... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 16030. ...Smith Read more

000
ABPZ20 KNHC 050550
TWOEP

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
1100 PM PDT Sun Aug 4 2024

For the eastern North Pacific...east of 140 degrees west longitude:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical
Storm Carlotta, on Tropical Storm Daniel, and on recently formed
Tropical Storm Emilia, all located well offshore of the coast of
Mexico.

South of Southwestern Mexico (EP96):
Shower and thunderstorm activity continues to show signs of
organization in association with an area of low pressure located a
few hundred miles south of southwestern Mexico. Environmental
conditions remain conducive for development, and a tropical
depression is likely to form within the next day or so while the
system moves generally west-northwestward at 10 to 15 mph, remaining
well offshore of the coast of Mexico. For more information on this
system, including Gale Warnings, see High Seas Forecasts issued by
the National Weather Service.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 7 days...high...90 percent.

&&
Public Advisories on Tropical Storm Emilia are issued under
WMO header WTPZ35 KNHC and under AWIPS header MIATCPEP5.
Forecast/Advisories on Tropical Storm Emilia are issued under
WMO header WTPZ25 KNHC and under AWIPS header MIATCMEP5.

High Seas Forecasts issued by the National Weather Service
can be found under AWIPS header NFDHSFEPI, WMO header FZPN02
KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php

$$
Forecaster Bucci

MD 1820 CONCERNING TORNADO WATCH 595... FOR PARTS OF CENTRAL AND NORTHERN FLORIDA
Mesoscale Discussion 1820 NWS Storm Prediction Center Norman OK 1131 PM CDT Sun Aug 04 2024 Areas affected...parts of central and northern Florida Concerning...Tornado Watch 595... Valid 050431Z - 050630Z The severe weather threat for Tornado Watch 595 continues. SUMMARY...Risk for a couple of tornadoes continues. DISCUSSION...Latest radar loop shows some wobble of the center of Hurricane Debby over the past 1 to 2 hours, though it appears that a gradual northward advance has commenced recently. Otherwise, the strongest convective bands remain centered across west-central Florida, as has been the case for several hours. Little change in the intensity of the bands is noted, though some decrease in the number of rotating cells has occurred. Still, with the low-level wind field more than sufficient to support rotating cells, occasional/brief tornadic spin-ups remain likely over the next several hours. ..Goss.. 08/05/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MLB...TBW...JAX...TAE... LAT...LON 28748378 29368403 30128393 30368236 30108182 29218160 28698149 27648183 27548197 26848248 27478297 28628313 28748378 Read more

WW 0595 Status Updates
STATUS REPORT ON WW 595 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E TLH TO 35 SSE VLD TO 35 W DAB TO 10 SE AYS. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1820. ..GRAMS..08/05/24 ATTN...WFO...JAX...MLB...TBW...TAE... STATUS REPORT FOR WT 595 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC001-017-029-031-035-041-049-053-057-067-069-075-081-083-089- 101-103-105-109-115-119-121-123-127-050640- FL . FLORIDA COUNTIES INCLUDED ARE ALACHUA CITRUS DIXIE DUVAL FLAGLER GILCHRIST HARDEE HERNANDO HILLSBOROUGH LAFAYETTE LAKE LEVY MANATEE MARION NASSAU PASCO PINELLAS POLK ST. JOHNS SARASOTA SUMTER SUWANNEE TAYLOR VOLUSIA GAC039-050640- GA . GEORGIA COUNTIES INCLUDED ARE CAMDEN Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more