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MD 0767 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL FLORIDA NORTHWARD TOWARD SOUTHEAST GEORGIA
Mesoscale Discussion 0767 NWS Storm Prediction Center Norman OK 0221 PM CDT Sun May 11 2025 Areas affected...central Florida northward toward southeast Georgia Concerning...Severe potential...Watch unlikely Valid 111921Z - 112145Z Probability of Watch Issuance...20 percent SUMMARY...Storms are forecast to increase in coverage throughout the afternoon from the central Florida Peninsula into northeast Florida and southeast Georgia. DISCUSSION...Storms are currently increasing east of Tampa to west of Okeechobee where strong heating has led to strong instability. The southerly flow regime should support a north/northeast movement to this development, affecting the remainder of central into northeastern Florida. Breaks in the clouds in those downstream areas are developing, and this should further increase instability. Although temperatures aloft are not as cool as previous days, MUCAPE over 2000 J/kg and deep-layer shear of 35-40 kt will support cellular storm mode with sporadic hail > 1.00" expected. Locally strong to damaging gusts cannot be ruled out as well, especially with any merging outflows. ..Jewell/Mosier.. 05/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MFL...MLB...TBW...JAX... LAT...LON 27158103 27348165 27658206 28098211 30438218 30958218 31328183 31328151 31148134 30518136 29698113 29078080 28408044 27888038 27308059 27158103 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

MD 0765 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN IDAHO INTO WESTERN WYOMING AND SOUTHWEST MONTANA
Mesoscale Discussion 0765 NWS Storm Prediction Center Norman OK 0139 PM CDT Sun May 11 2025 Areas affected...eastern Idaho into western Wyoming and southwest Montana Concerning...Severe potential...Watch possible Valid 111839Z - 112115Z Probability of Watch Issuance...40 percent SUMMARY...Storms should gradually increase in coverage and intensity from eastern Idaho into southwest Montana, with both hail and gust potential. DISCUSSION...A line of convection continue to increase in intensity over the upper Snake River Plain, with both strong heating and low-level warm advection ahead of it. Continued steepening of deep-layer lapse rates as the upper trough moves in the from the west and more heating should support further strengthening of this convection. Strong deep-layer shear will favor hail production with these storms over eastern ID. A brief/weak tornado cannot be ruled out with the stronger cells this afternoon, as low-level stretching is maximized. Farther north toward the Bitterroots, stronger cooling aloft is occurring, and areas of heating persist ahead of this activity as well. Long hodographs and cold midlevel temperatures will favor hail with these storms through the day. ..Jewell/Mosier.. 05/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...RIW...TFX...PIH...MSO... LAT...LON 42041299 42051382 42701393 43631329 44321328 45071381 45711419 46261407 46871302 46801187 46511101 45681004 45310990 44360984 42881087 42041299 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

WW 0245 Status Updates
STATUS REPORT ON WW 245 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..JEWELL..05/11/25 ATTN...WFO...PIH...SLC...RIW... STATUS REPORT FOR WS 245 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IDC005-007-011-013-019-023-029-031-033-041-043-051-063-065-067- 071-077-081-112140- ID . IDAHO COUNTIES INCLUDED ARE BANNOCK BEAR LAKE BINGHAM BLAINE BONNEVILLE BUTTE CARIBOU CASSIA CLARK FRANKLIN FREMONT JEFFERSON LINCOLN MADISON MINIDOKA ONEIDA POWER TETON UTC003-005-011-029-033-035-043-045-049-051-057-112140- UT . UTAH COUNTIES INCLUDED ARE BOX ELDER CACHE DAVIS MORGAN RICH SALT LAKE SUMMIT TOOELE UTAH WASATCH WEBER WYC023-029-035-039-041-112140- Read more

WW 0245 Status Updates
STATUS REPORT ON WW 245 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..JEWELL..05/11/25 ATTN...WFO...PIH...SLC...RIW... STATUS REPORT FOR WS 245 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IDC005-007-011-013-019-023-029-031-033-041-043-051-063-065-067- 071-077-081-112140- ID . IDAHO COUNTIES INCLUDED ARE BANNOCK BEAR LAKE BINGHAM BLAINE BONNEVILLE BUTTE CARIBOU CASSIA CLARK FRANKLIN FREMONT JEFFERSON LINCOLN MADISON MINIDOKA ONEIDA POWER TETON UTC003-005-011-029-033-035-043-045-049-051-057-112140- UT . UTAH COUNTIES INCLUDED ARE BOX ELDER CACHE DAVIS MORGAN RICH SALT LAKE SUMMIT TOOELE UTAH WASATCH WEBER WYC023-029-035-039-041-112140- Read more

WW 0245 Status Updates
STATUS REPORT ON WW 245 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..JEWELL..05/11/25 ATTN...WFO...PIH...SLC...RIW... STATUS REPORT FOR WS 245 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IDC005-007-011-013-019-023-029-031-033-041-043-051-063-065-067- 071-077-081-112140- ID . IDAHO COUNTIES INCLUDED ARE BANNOCK BEAR LAKE BINGHAM BLAINE BONNEVILLE BUTTE CARIBOU CASSIA CLARK FRANKLIN FREMONT JEFFERSON LINCOLN MADISON MINIDOKA ONEIDA POWER TETON UTC003-005-011-029-033-035-043-045-049-051-057-112140- UT . UTAH COUNTIES INCLUDED ARE BOX ELDER CACHE DAVIS MORGAN RICH SALT LAKE SUMMIT TOOELE UTAH WASATCH WEBER WYC023-029-035-039-041-112140- Read more

WW 245 SEVERE TSTM ID UT WY 111910Z - 120200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 245 NWS Storm Prediction Center Norman OK 110 PM MDT Sun May 11 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Idaho Northern Utah Western Wyoming * Effective this Sunday afternoon and evening from 110 PM until 800 PM MDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 80 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorm intensity and coverage is expected to increase this afternoon across eastern ID, northern UT, and western WY. Environmental conditions support the potential for strong to severe storms capable of strong gusts. Isolated large hail is also possible, particularly in areas of higher terrain. The severe thunderstorm watch area is approximately along and 80 statute miles east and west of a line from 65 miles north northeast of Idaho Falls ID to 40 miles southwest of Salt Lake City UT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for 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. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 23035. ...Mosier Read more

MD 0766 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF SOUTHEAST GEORGIA
Mesoscale Discussion 0766 NWS Storm Prediction Center Norman OK 0149 PM CDT Sun May 11 2025 Areas affected...Portions of southeast Georgia Concerning...Severe potential...Watch unlikely Valid 111849Z - 112045Z Probability of Watch Issuance...20 percent SUMMARY...A locally greater risk for damaging winds and perhaps a tornado is evident in southeast Georgia near a local warm front feature. DISCUSSION...A small corridor in southeast Georgia has heated into the low 80s F. A few weak discrete cells exist near the Georgia/South Carolina state line. One cell has recently intensified and shown signs of low-level rotation. The localized warm front feature will promote at least marginal potential for a brief tornado with southeasterly winds near the boundary. Nearby KCLX radar accordingly shows modest 0-1 km SRH. Over the next hour or two this environment will support a locally greater risk for damaging winds and perhaps a tornado. The discrete cells will have the greatest potential, but stronger updrafts within the linear segment farther southwest could also acquire low-level rotation as well. ..Wendt/Mosier.. 05/11/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...JAX...FFC... LAT...LON 31138191 31648223 32088233 32288211 32298142 32188097 31928092 31258140 31018156 30958174 31138191 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Sun May 11 2025 Valid 112000Z - 121200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN ROCKIES/GREAT BASIN AND MONTANA HIGH PLAINS... ...SUMMARY... Scattered severe wind gusts are expected across the northern Rockies/Great Basin and the Montana High Plains from mid-afternoon into the evening. Isolated severe thunderstorms are also possible across the Southeast today through tonight. ...20Z Update... The only noteworthy change with this update was a southwestward expansion of the Slight Risk area into northern UT, driven by 15-percent severe wind probabilities. Here, ample diurnal heating has resulted in a deep/dry boundary layer supportive of scattered severe wind gusts accompanying high-based storms. Reference Severe Thunderstorm Watch #245 for more details. Farther east, isolated severe storms capable of producing locally damaging winds and marginally severe hail remain possible across the Southeast into this evening. Reference MCDs #766/767 for details. ..Weinman.. 05/11/2025 .PREV DISCUSSION... /ISSUED 1119 AM CDT Sun May 11 2025/ ...Northern Rockies/High Plains and northeast Great Basin... Strengthening southwesterly flow aloft is anticipated throughout the day as the upper low off the Pacific Northwest coast progresses eastward and a lead shortwave trough pivots through OR/northern CA into the northern Rockies. Strong heating will help destabilize the airmass downstream from the northern Rockies into the northern High Plains. Large-scale ascent attendant to the approaching shortwave trough, coupled with orographic lift, will help initiate storms across the high terrain during the afternoon within this destabilized airmass. Environmental conditions suggest some supercells are possible with this initial development, with damaging gusts and isolated hail as the primary risk. A low-probability corridor of tornado potential exists across southeast ID. The storms should encounter an increasingly mixed environment with eastern/northeastern extent into central MT, with strong gusts becoming the primary severe hazard as storms trend towards more outflow-dominant linear structures. ...Southeast States... Recent satellite imagery and surface observations continue to show the vertically stacked low over the Lower MS Valley, with broad swath of southwesterly flow extending south and east of this low from the central Gulf into FL. Surface features have become increasingly diffuse across the Southeast and FL over the past two days given the persistence of this low and associated precipitation, but recent surface analysis shows a weak and wavy stationary boundary extending from the low over the ArkLaMiss southeastward to the AL/FL Panhandle border before arcing back northeastward across southern GA. Scattered thunderstorms are ongoing and the general expectation is for scattered to numerous thunderstorms to persist across much of the region throughout the day. Widespread cloudiness should limit heating, but ample low-level moisture will still support modest buoyancy. Shear will gradually increase as the low to mid-level flow strengthens this afternoon and evening, which could lead to some transient storm organization, but in general convection is expected to be disorganized, outflow-dominated multicells. Even so, isolated damaging gusts are possible. Some low-probability tornado potential exists as well, particularly along the stationary boundary across southern GA around 00Z. Farther northwest across AL/MS and into eastern AR, the airmass is forecast to destabilize this afternoon as heating occurs beneath cool temperatures aloft. Even with the cooler temperature aloft, overall buoyancy will be modest given the somewhat cool low to mid-level thermodynamic profile. Even so, a nearly unidirectional southeasterly wind profile with moderate deep-layer speed shear could support brief updraft organization. As a result, a few cells may briefly produce marginally severe hail and locally strong gusts, and possibly some funnel/brief tornado potential, from late afternoon through early/mid-evening. Read more