SPC Day 2 Fire Weather Outlook

1 year ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0158 AM CDT Sat Aug 03 2024 Valid 041200Z - 051200Z ...Synopsis... A midlevel disturbance moving across the Great Basin into the northern Rockies will bring isolated dry thunderstorm chances across eastern Oregon into Idaho southward and eastward into Utah and Wyoming. In these regions, mid-level moisture will overlap dry surface conditions with faster storm motions. With little to no precipitation expected, dry fuels within these regions will support potential for new ignitions. Gusty and erratic outflow will also be possible. Better potential for wetting rainfall into central/northern Montana precludes the need to include these areas, though fuels in these regions are also sufficiently dry. ..Thornton.. 08/03/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...Synopsis... A midlevel disturbance will move northward along the western periphery of the anticyclone across the western US, bring showers and thunderstorms across the Sierra Nevada range and into the Northwest late afternoon into the evening. Further east and north, dry thunderstorms will also be possible across portions of the Great Basin and far western Montana this afternoon. These storms will have potential to produce gusty and erratic outflow winds. Dry fuels within these regions will support potential for new ignitions. Portions of the previous isolated dry thunderstorm risk were removed across central/northern California and central Oregon, where precipitable water values 1.00"+ will likely permit wetting rainfall. ..Thornton.. 08/03/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...Synopsis... A midlevel disturbance will move northward along the western periphery of the anticyclone across the western US, bring showers and thunderstorms across the Sierra Nevada range and into the Northwest late afternoon into the evening. Further east and north, dry thunderstorms will also be possible across portions of the Great Basin and far western Montana this afternoon. These storms will have potential to produce gusty and erratic outflow winds. Dry fuels within these regions will support potential for new ignitions. Portions of the previous isolated dry thunderstorm risk were removed across central/northern California and central Oregon, where precipitable water values 1.00"+ will likely permit wetting rainfall. ..Thornton.. 08/03/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...Synopsis... A midlevel disturbance will move northward along the western periphery of the anticyclone across the western US, bring showers and thunderstorms across the Sierra Nevada range and into the Northwest late afternoon into the evening. Further east and north, dry thunderstorms will also be possible across portions of the Great Basin and far western Montana this afternoon. These storms will have potential to produce gusty and erratic outflow winds. Dry fuels within these regions will support potential for new ignitions. Portions of the previous isolated dry thunderstorm risk were removed across central/northern California and central Oregon, where precipitable water values 1.00"+ will likely permit wetting rainfall. ..Thornton.. 08/03/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook

1 year ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...Synopsis... A midlevel disturbance will move northward along the western periphery of the anticyclone across the western US, bring showers and thunderstorms across the Sierra Nevada range and into the Northwest late afternoon into the evening. Further east and north, dry thunderstorms will also be possible across portions of the Great Basin and far western Montana this afternoon. These storms will have potential to produce gusty and erratic outflow winds. Dry fuels within these regions will support potential for new ignitions. Portions of the previous isolated dry thunderstorm risk were removed across central/northern California and central Oregon, where precipitable water values 1.00"+ will likely permit wetting rainfall. ..Thornton.. 08/03/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Aug 3, 2024 0600 UTC Day 2 Convective Outlook

1 year ago
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CDT Sat Aug 03 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY INTO SUNDAY NIGHT ACROSS PARTS OF CENTRAL INTO NORTHEASTERN FLORIDA AND ADJACENT SOUTHEASTERN GEORGIA...SOUTHERN MINNESOTA AND ADJACENT PORTIONS OF EASTERN SOUTH DAKOTA...NORTHERN IOWA...AND SOUTHWESTERN WISCONSIN...SOUTH CENTRAL INTO SOUTHEASTERN MONTANA AND ADJACENT NORTHERN WYOMING... ...SUMMARY... Widely scattered strong thunderstorms may pose at least some risk for severe weather across parts of central into northeastern Florida and adjacent southeastern Georgia, portions of the upper Mississippi Valley and portions of the northern Rockies Sunday through Sunday night. ...Synopsis... Models indicate that mid-level flow across the northern mid-latitudes will remain amplified, with a notable mid-level high continuing to evolve over the Canadian Yukon Territory vicinity Sunday through Sunday night. Downstream, seasonably strong cyclonic flow likely will be maintained across the upper Great Lakes vicinity through St. Lawrence Valley, to the south of a prominent cyclone slowly migrating eastward across northern Quebec. In lower latitudes, a prominent high is forecast to remain centered across the Four Corners vicinity, while higher heights also begin to elongate eastward across the southern Rockies into the central Great Plains. Within modest westerly flow on the northern periphery of this feature, low-amplitude troughing may progress across and east-southeast of the northern Rockies into the Dakotas. Seasonably high moisture content (including a plume of precipitable water in excess of 2 inches) will remain largely confined to along and east of a weakening mid-level trough/shear axis, between the Western Ridging and ridging over the subtropical western Atlantic. While this is forecast to shift offshore of the northern Atlantic Seaboard, to the south of the Quebec cyclone, it likely will linger near the southern Mid Atlantic coast through the Florida Peninsula, and be reinforced by a surge of tropical moisture associated with a developing tropical cyclone emerging from the Caribbean. Beneath a lingering plume of warm-elevated mixed-layer air extending east-southeast of the northern Rockies, toward the upper Mississippi Valley, residual low-level moisture, enhanced by evapotranspiration, may contribute to a corridor of moderate to strong potential instability near a stalling surface frontal zone. ...Southeast... The risk for severe weather Sunday through Sunday night still appears largely conditional at the present time, due to the typical uncertainties accompanying a developing landfalling tropical system at this extended time frame. However, based on the current forecast track of what is expected to be a developing tropical storm, west-southwest of Tampa Bay early Sunday into the Big Bend vicinity by early Monday, much of central through northeastern Florida may be impacted by a period of enlarging clockwise-curved low-level hodographs, coincident with a tropically moist and unstable boundary-layer. This environment may become supportive of a risk for tornadoes. ...Northern Rockies... Model forecast soundings suggest that the boundary-layer may become very warm, deeply mixed and characterized by at least weak instability across much of southeastern into south central Montana by late Sunday afternoon, before an evolving cluster of thunderstorms begins to propagate east-southeast of the higher terrain. It appears that this convective development will be aided by forcing associated with the low-amplitude perturbation which may include a 30-40+ kt westerly mid-level speed maximum. Downward mixing of this momentum, coupled with the thermodynamic forcing, probably will contribute to a few strong to severe surface gusts, before the convection weakens Sunday evening. ...Northern Great Plains/Upper Mississippi Valley... Convective potential remains unclear due to model variability and uncertain forcing for thunderstorm development within the corridor of strong potential instability near the stalled frontal zone. However, models suggest that mid-level inhibition may become weaker across the upper Mississippi Valley portion of the surface front, relative to upstream across the northern Great Plains. Isolated thunderstorm development may not be out of the question during the peak late afternoon heating. Otherwise, forcing on the nose of a nocturnally strengthening and veering low-level jet might support thunderstorm development late Sunday evening and overnight. ..Kerr.. 08/03/2024 Read more

SPC Aug 3, 2024 0600 UTC Day 2 Convective Outlook

1 year ago
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CDT Sat Aug 03 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY INTO SUNDAY NIGHT ACROSS PARTS OF CENTRAL INTO NORTHEASTERN FLORIDA AND ADJACENT SOUTHEASTERN GEORGIA...SOUTHERN MINNESOTA AND ADJACENT PORTIONS OF EASTERN SOUTH DAKOTA...NORTHERN IOWA...AND SOUTHWESTERN WISCONSIN...SOUTH CENTRAL INTO SOUTHEASTERN MONTANA AND ADJACENT NORTHERN WYOMING... ...SUMMARY... Widely scattered strong thunderstorms may pose at least some risk for severe weather across parts of central into northeastern Florida and adjacent southeastern Georgia, portions of the upper Mississippi Valley and portions of the northern Rockies Sunday through Sunday night. ...Synopsis... Models indicate that mid-level flow across the northern mid-latitudes will remain amplified, with a notable mid-level high continuing to evolve over the Canadian Yukon Territory vicinity Sunday through Sunday night. Downstream, seasonably strong cyclonic flow likely will be maintained across the upper Great Lakes vicinity through St. Lawrence Valley, to the south of a prominent cyclone slowly migrating eastward across northern Quebec. In lower latitudes, a prominent high is forecast to remain centered across the Four Corners vicinity, while higher heights also begin to elongate eastward across the southern Rockies into the central Great Plains. Within modest westerly flow on the northern periphery of this feature, low-amplitude troughing may progress across and east-southeast of the northern Rockies into the Dakotas. Seasonably high moisture content (including a plume of precipitable water in excess of 2 inches) will remain largely confined to along and east of a weakening mid-level trough/shear axis, between the Western Ridging and ridging over the subtropical western Atlantic. While this is forecast to shift offshore of the northern Atlantic Seaboard, to the south of the Quebec cyclone, it likely will linger near the southern Mid Atlantic coast through the Florida Peninsula, and be reinforced by a surge of tropical moisture associated with a developing tropical cyclone emerging from the Caribbean. Beneath a lingering plume of warm-elevated mixed-layer air extending east-southeast of the northern Rockies, toward the upper Mississippi Valley, residual low-level moisture, enhanced by evapotranspiration, may contribute to a corridor of moderate to strong potential instability near a stalling surface frontal zone. ...Southeast... The risk for severe weather Sunday through Sunday night still appears largely conditional at the present time, due to the typical uncertainties accompanying a developing landfalling tropical system at this extended time frame. However, based on the current forecast track of what is expected to be a developing tropical storm, west-southwest of Tampa Bay early Sunday into the Big Bend vicinity by early Monday, much of central through northeastern Florida may be impacted by a period of enlarging clockwise-curved low-level hodographs, coincident with a tropically moist and unstable boundary-layer. This environment may become supportive of a risk for tornadoes. ...Northern Rockies... Model forecast soundings suggest that the boundary-layer may become very warm, deeply mixed and characterized by at least weak instability across much of southeastern into south central Montana by late Sunday afternoon, before an evolving cluster of thunderstorms begins to propagate east-southeast of the higher terrain. It appears that this convective development will be aided by forcing associated with the low-amplitude perturbation which may include a 30-40+ kt westerly mid-level speed maximum. Downward mixing of this momentum, coupled with the thermodynamic forcing, probably will contribute to a few strong to severe surface gusts, before the convection weakens Sunday evening. ...Northern Great Plains/Upper Mississippi Valley... Convective potential remains unclear due to model variability and uncertain forcing for thunderstorm development within the corridor of strong potential instability near the stalled frontal zone. However, models suggest that mid-level inhibition may become weaker across the upper Mississippi Valley portion of the surface front, relative to upstream across the northern Great Plains. Isolated thunderstorm development may not be out of the question during the peak late afternoon heating. Otherwise, forcing on the nose of a nocturnally strengthening and veering low-level jet might support thunderstorm development late Sunday evening and overnight. ..Kerr.. 08/03/2024 Read more

SPC Aug 3, 2024 0600 UTC Day 2 Convective Outlook

1 year ago
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CDT Sat Aug 03 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY INTO SUNDAY NIGHT ACROSS PARTS OF CENTRAL INTO NORTHEASTERN FLORIDA AND ADJACENT SOUTHEASTERN GEORGIA...SOUTHERN MINNESOTA AND ADJACENT PORTIONS OF EASTERN SOUTH DAKOTA...NORTHERN IOWA...AND SOUTHWESTERN WISCONSIN...SOUTH CENTRAL INTO SOUTHEASTERN MONTANA AND ADJACENT NORTHERN WYOMING... ...SUMMARY... Widely scattered strong thunderstorms may pose at least some risk for severe weather across parts of central into northeastern Florida and adjacent southeastern Georgia, portions of the upper Mississippi Valley and portions of the northern Rockies Sunday through Sunday night. ...Synopsis... Models indicate that mid-level flow across the northern mid-latitudes will remain amplified, with a notable mid-level high continuing to evolve over the Canadian Yukon Territory vicinity Sunday through Sunday night. Downstream, seasonably strong cyclonic flow likely will be maintained across the upper Great Lakes vicinity through St. Lawrence Valley, to the south of a prominent cyclone slowly migrating eastward across northern Quebec. In lower latitudes, a prominent high is forecast to remain centered across the Four Corners vicinity, while higher heights also begin to elongate eastward across the southern Rockies into the central Great Plains. Within modest westerly flow on the northern periphery of this feature, low-amplitude troughing may progress across and east-southeast of the northern Rockies into the Dakotas. Seasonably high moisture content (including a plume of precipitable water in excess of 2 inches) will remain largely confined to along and east of a weakening mid-level trough/shear axis, between the Western Ridging and ridging over the subtropical western Atlantic. While this is forecast to shift offshore of the northern Atlantic Seaboard, to the south of the Quebec cyclone, it likely will linger near the southern Mid Atlantic coast through the Florida Peninsula, and be reinforced by a surge of tropical moisture associated with a developing tropical cyclone emerging from the Caribbean. Beneath a lingering plume of warm-elevated mixed-layer air extending east-southeast of the northern Rockies, toward the upper Mississippi Valley, residual low-level moisture, enhanced by evapotranspiration, may contribute to a corridor of moderate to strong potential instability near a stalling surface frontal zone. ...Southeast... The risk for severe weather Sunday through Sunday night still appears largely conditional at the present time, due to the typical uncertainties accompanying a developing landfalling tropical system at this extended time frame. However, based on the current forecast track of what is expected to be a developing tropical storm, west-southwest of Tampa Bay early Sunday into the Big Bend vicinity by early Monday, much of central through northeastern Florida may be impacted by a period of enlarging clockwise-curved low-level hodographs, coincident with a tropically moist and unstable boundary-layer. This environment may become supportive of a risk for tornadoes. ...Northern Rockies... Model forecast soundings suggest that the boundary-layer may become very warm, deeply mixed and characterized by at least weak instability across much of southeastern into south central Montana by late Sunday afternoon, before an evolving cluster of thunderstorms begins to propagate east-southeast of the higher terrain. It appears that this convective development will be aided by forcing associated with the low-amplitude perturbation which may include a 30-40+ kt westerly mid-level speed maximum. Downward mixing of this momentum, coupled with the thermodynamic forcing, probably will contribute to a few strong to severe surface gusts, before the convection weakens Sunday evening. ...Northern Great Plains/Upper Mississippi Valley... Convective potential remains unclear due to model variability and uncertain forcing for thunderstorm development within the corridor of strong potential instability near the stalled frontal zone. However, models suggest that mid-level inhibition may become weaker across the upper Mississippi Valley portion of the surface front, relative to upstream across the northern Great Plains. Isolated thunderstorm development may not be out of the question during the peak late afternoon heating. Otherwise, forcing on the nose of a nocturnally strengthening and veering low-level jet might support thunderstorm development late Sunday evening and overnight. ..Kerr.. 08/03/2024 Read more

SPC Aug 3, 2024 0600 UTC Day 2 Convective Outlook

1 year ago
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1200 AM CDT Sat Aug 03 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY INTO SUNDAY NIGHT ACROSS PARTS OF CENTRAL INTO NORTHEASTERN FLORIDA AND ADJACENT SOUTHEASTERN GEORGIA...SOUTHERN MINNESOTA AND ADJACENT PORTIONS OF EASTERN SOUTH DAKOTA...NORTHERN IOWA...AND SOUTHWESTERN WISCONSIN...SOUTH CENTRAL INTO SOUTHEASTERN MONTANA AND ADJACENT NORTHERN WYOMING... ...SUMMARY... Widely scattered strong thunderstorms may pose at least some risk for severe weather across parts of central into northeastern Florida and adjacent southeastern Georgia, portions of the upper Mississippi Valley and portions of the northern Rockies Sunday through Sunday night. ...Synopsis... Models indicate that mid-level flow across the northern mid-latitudes will remain amplified, with a notable mid-level high continuing to evolve over the Canadian Yukon Territory vicinity Sunday through Sunday night. Downstream, seasonably strong cyclonic flow likely will be maintained across the upper Great Lakes vicinity through St. Lawrence Valley, to the south of a prominent cyclone slowly migrating eastward across northern Quebec. In lower latitudes, a prominent high is forecast to remain centered across the Four Corners vicinity, while higher heights also begin to elongate eastward across the southern Rockies into the central Great Plains. Within modest westerly flow on the northern periphery of this feature, low-amplitude troughing may progress across and east-southeast of the northern Rockies into the Dakotas. Seasonably high moisture content (including a plume of precipitable water in excess of 2 inches) will remain largely confined to along and east of a weakening mid-level trough/shear axis, between the Western Ridging and ridging over the subtropical western Atlantic. While this is forecast to shift offshore of the northern Atlantic Seaboard, to the south of the Quebec cyclone, it likely will linger near the southern Mid Atlantic coast through the Florida Peninsula, and be reinforced by a surge of tropical moisture associated with a developing tropical cyclone emerging from the Caribbean. Beneath a lingering plume of warm-elevated mixed-layer air extending east-southeast of the northern Rockies, toward the upper Mississippi Valley, residual low-level moisture, enhanced by evapotranspiration, may contribute to a corridor of moderate to strong potential instability near a stalling surface frontal zone. ...Southeast... The risk for severe weather Sunday through Sunday night still appears largely conditional at the present time, due to the typical uncertainties accompanying a developing landfalling tropical system at this extended time frame. However, based on the current forecast track of what is expected to be a developing tropical storm, west-southwest of Tampa Bay early Sunday into the Big Bend vicinity by early Monday, much of central through northeastern Florida may be impacted by a period of enlarging clockwise-curved low-level hodographs, coincident with a tropically moist and unstable boundary-layer. This environment may become supportive of a risk for tornadoes. ...Northern Rockies... Model forecast soundings suggest that the boundary-layer may become very warm, deeply mixed and characterized by at least weak instability across much of southeastern into south central Montana by late Sunday afternoon, before an evolving cluster of thunderstorms begins to propagate east-southeast of the higher terrain. It appears that this convective development will be aided by forcing associated with the low-amplitude perturbation which may include a 30-40+ kt westerly mid-level speed maximum. Downward mixing of this momentum, coupled with the thermodynamic forcing, probably will contribute to a few strong to severe surface gusts, before the convection weakens Sunday evening. ...Northern Great Plains/Upper Mississippi Valley... Convective potential remains unclear due to model variability and uncertain forcing for thunderstorm development within the corridor of strong potential instability near the stalled frontal zone. However, models suggest that mid-level inhibition may become weaker across the upper Mississippi Valley portion of the surface front, relative to upstream across the northern Great Plains. Isolated thunderstorm development may not be out of the question during the peak late afternoon heating. Otherwise, forcing on the nose of a nocturnally strengthening and veering low-level jet might support thunderstorm development late Sunday evening and overnight. ..Kerr.. 08/03/2024 Read more

SPC Aug 3, 2024 0600 UTC Day 1 Convective Outlook

1 year ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL/EASTERN NORTH CAROLINA INTO SOUTHEAST PENNSYLVANIA AND SOUTHERN NEW JERSEY...AND ACROSS EASTERN SOUTH DAKOTA...CENTRAL/SOUTHERN MINNESOTA AND EXTREME NORTHWEST IOWA... ...SUMMARY... Scattered severe storms are most likely this afternoon and evening from eastern South Dakota into Minnesota with damaging winds and hail possible. Scattered thunderstorms producing damaging gusts are also expected across parts of the North Carolina Piedmont into the Mid-Atlantic vicinity. A developing tropical cyclone may also impact the Florida Keys and western Florida Peninsula. Meanwhile, isolated strong storms are possible across the southern High Plains. ...Mid-Atlantic Vicinity into SC/GA... An upper trough oriented from the lower Great Lakes/Ohio Valley to northern AL/GA will shift east toward the northern Appalachians and Mid-Atlantic vicinity through tonight. This will result in a belt of 25-35 kt southwesterly midlevel flow overspreading the NC/VA Piedmont, northward toward southern New England. A surface front will stall from eastern PA southwestward along the Blue Ridge Mountains and into north GA. To the east of this surface boundary, a very moist airmass will be in place, with dewpoints in the 70s F. This will aid in moderate destabilization, with MLCAPE values 1500-2000 J/kg common. A few pockets with higher instability are possible, but poor midlevel lapse rates will limit stronger destabilization on a large scale. Nevertheless, 25-35 kt effective shear magnitudes will support strong to severe thunderstorms. Thunderstorm clusters will be possible, and scattered wind damage is expected with this activity. A corridor of greater severe potential is expected from central NC into southeast PA/southern NJ, where greater storm coverage is expected along with increased potential for forward-propagating clusters. A Slight (level 2 of 5) risk has been included for this corridor. ...Eastern Dakotas/Upper Midwest... Moderate northwesterly mid/upper flow will overspread the region on the western periphery of a large Hudson Bay upper cyclone. A weak surface low is forecast to develop over central SD, with a warm front extending from southwest MN into central/eastern IA, and a cold front developing southward across northern MN and the Dakotas. A wedge of mid 60s to low 70s F dewpoints between these surface features will foster moderate to strong destabilization during the afternoon amid steep midlevel lapse rates. Vertically veering wind profiles and elongated/straight hodographs, along with effective shear magnitudes around 25-35 kt, should favor supercells. Damaging gusts and large to very large hail will be possible with this activity. Initial cellular activity may develop into a small MCS, transitioning the risk to mainly damaging winds during the evening. ...Southwest FL Peninsula... Per latest NHC guidance, Tropical Depression Four is forecast to become a tropical storm by this evening as the system tracks over the eastern Gulf of Mexico. Scattered thunderstorms will overspread the southern Peninsula, where low/mid level east/southeasterly flow will increase through the period. Sufficient low-level instability and 0-1 km SRH increasing to greater than 200 m2/s2 will support some risk for a couple of tornadoes. ...Southern High Plains... A convectively enhanced vorticity max is forecast to develop south across the central/southern High Plains vicinity this afternoon/evening. Vertically veering wind profiles will support rather robust effective shear magnitudes greater than 40 kt. Boundary-layer moisture will remain modest, but steep midlevel lapse rates will aid in at least weak destabilization (MLCAPE around 500-1000 J/kg) sufficient for high-based thunderstorm development. A deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow winds with any storms that develop. If any longer-lived cells can be maintained, isolated large hail is also possible. ..Leitman/Thornton.. 08/03/2024 Read more

SPC Aug 3, 2024 0600 UTC Day 1 Convective Outlook

1 year ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL/EASTERN NORTH CAROLINA INTO SOUTHEAST PENNSYLVANIA AND SOUTHERN NEW JERSEY...AND ACROSS EASTERN SOUTH DAKOTA...CENTRAL/SOUTHERN MINNESOTA AND EXTREME NORTHWEST IOWA... ...SUMMARY... Scattered severe storms are most likely this afternoon and evening from eastern South Dakota into Minnesota with damaging winds and hail possible. Scattered thunderstorms producing damaging gusts are also expected across parts of the North Carolina Piedmont into the Mid-Atlantic vicinity. A developing tropical cyclone may also impact the Florida Keys and western Florida Peninsula. Meanwhile, isolated strong storms are possible across the southern High Plains. ...Mid-Atlantic Vicinity into SC/GA... An upper trough oriented from the lower Great Lakes/Ohio Valley to northern AL/GA will shift east toward the northern Appalachians and Mid-Atlantic vicinity through tonight. This will result in a belt of 25-35 kt southwesterly midlevel flow overspreading the NC/VA Piedmont, northward toward southern New England. A surface front will stall from eastern PA southwestward along the Blue Ridge Mountains and into north GA. To the east of this surface boundary, a very moist airmass will be in place, with dewpoints in the 70s F. This will aid in moderate destabilization, with MLCAPE values 1500-2000 J/kg common. A few pockets with higher instability are possible, but poor midlevel lapse rates will limit stronger destabilization on a large scale. Nevertheless, 25-35 kt effective shear magnitudes will support strong to severe thunderstorms. Thunderstorm clusters will be possible, and scattered wind damage is expected with this activity. A corridor of greater severe potential is expected from central NC into southeast PA/southern NJ, where greater storm coverage is expected along with increased potential for forward-propagating clusters. A Slight (level 2 of 5) risk has been included for this corridor. ...Eastern Dakotas/Upper Midwest... Moderate northwesterly mid/upper flow will overspread the region on the western periphery of a large Hudson Bay upper cyclone. A weak surface low is forecast to develop over central SD, with a warm front extending from southwest MN into central/eastern IA, and a cold front developing southward across northern MN and the Dakotas. A wedge of mid 60s to low 70s F dewpoints between these surface features will foster moderate to strong destabilization during the afternoon amid steep midlevel lapse rates. Vertically veering wind profiles and elongated/straight hodographs, along with effective shear magnitudes around 25-35 kt, should favor supercells. Damaging gusts and large to very large hail will be possible with this activity. Initial cellular activity may develop into a small MCS, transitioning the risk to mainly damaging winds during the evening. ...Southwest FL Peninsula... Per latest NHC guidance, Tropical Depression Four is forecast to become a tropical storm by this evening as the system tracks over the eastern Gulf of Mexico. Scattered thunderstorms will overspread the southern Peninsula, where low/mid level east/southeasterly flow will increase through the period. Sufficient low-level instability and 0-1 km SRH increasing to greater than 200 m2/s2 will support some risk for a couple of tornadoes. ...Southern High Plains... A convectively enhanced vorticity max is forecast to develop south across the central/southern High Plains vicinity this afternoon/evening. Vertically veering wind profiles will support rather robust effective shear magnitudes greater than 40 kt. Boundary-layer moisture will remain modest, but steep midlevel lapse rates will aid in at least weak destabilization (MLCAPE around 500-1000 J/kg) sufficient for high-based thunderstorm development. A deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow winds with any storms that develop. If any longer-lived cells can be maintained, isolated large hail is also possible. ..Leitman/Thornton.. 08/03/2024 Read more

SPC Aug 3, 2024 0600 UTC Day 1 Convective Outlook

1 year ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL/EASTERN NORTH CAROLINA INTO SOUTHEAST PENNSYLVANIA AND SOUTHERN NEW JERSEY...AND ACROSS EASTERN SOUTH DAKOTA...CENTRAL/SOUTHERN MINNESOTA AND EXTREME NORTHWEST IOWA... ...SUMMARY... Scattered severe storms are most likely this afternoon and evening from eastern South Dakota into Minnesota with damaging winds and hail possible. Scattered thunderstorms producing damaging gusts are also expected across parts of the North Carolina Piedmont into the Mid-Atlantic vicinity. A developing tropical cyclone may also impact the Florida Keys and western Florida Peninsula. Meanwhile, isolated strong storms are possible across the southern High Plains. ...Mid-Atlantic Vicinity into SC/GA... An upper trough oriented from the lower Great Lakes/Ohio Valley to northern AL/GA will shift east toward the northern Appalachians and Mid-Atlantic vicinity through tonight. This will result in a belt of 25-35 kt southwesterly midlevel flow overspreading the NC/VA Piedmont, northward toward southern New England. A surface front will stall from eastern PA southwestward along the Blue Ridge Mountains and into north GA. To the east of this surface boundary, a very moist airmass will be in place, with dewpoints in the 70s F. This will aid in moderate destabilization, with MLCAPE values 1500-2000 J/kg common. A few pockets with higher instability are possible, but poor midlevel lapse rates will limit stronger destabilization on a large scale. Nevertheless, 25-35 kt effective shear magnitudes will support strong to severe thunderstorms. Thunderstorm clusters will be possible, and scattered wind damage is expected with this activity. A corridor of greater severe potential is expected from central NC into southeast PA/southern NJ, where greater storm coverage is expected along with increased potential for forward-propagating clusters. A Slight (level 2 of 5) risk has been included for this corridor. ...Eastern Dakotas/Upper Midwest... Moderate northwesterly mid/upper flow will overspread the region on the western periphery of a large Hudson Bay upper cyclone. A weak surface low is forecast to develop over central SD, with a warm front extending from southwest MN into central/eastern IA, and a cold front developing southward across northern MN and the Dakotas. A wedge of mid 60s to low 70s F dewpoints between these surface features will foster moderate to strong destabilization during the afternoon amid steep midlevel lapse rates. Vertically veering wind profiles and elongated/straight hodographs, along with effective shear magnitudes around 25-35 kt, should favor supercells. Damaging gusts and large to very large hail will be possible with this activity. Initial cellular activity may develop into a small MCS, transitioning the risk to mainly damaging winds during the evening. ...Southwest FL Peninsula... Per latest NHC guidance, Tropical Depression Four is forecast to become a tropical storm by this evening as the system tracks over the eastern Gulf of Mexico. Scattered thunderstorms will overspread the southern Peninsula, where low/mid level east/southeasterly flow will increase through the period. Sufficient low-level instability and 0-1 km SRH increasing to greater than 200 m2/s2 will support some risk for a couple of tornadoes. ...Southern High Plains... A convectively enhanced vorticity max is forecast to develop south across the central/southern High Plains vicinity this afternoon/evening. Vertically veering wind profiles will support rather robust effective shear magnitudes greater than 40 kt. Boundary-layer moisture will remain modest, but steep midlevel lapse rates will aid in at least weak destabilization (MLCAPE around 500-1000 J/kg) sufficient for high-based thunderstorm development. A deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow winds with any storms that develop. If any longer-lived cells can be maintained, isolated large hail is also possible. ..Leitman/Thornton.. 08/03/2024 Read more

SPC Aug 3, 2024 0600 UTC Day 1 Convective Outlook

1 year ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sat Aug 03 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL/EASTERN NORTH CAROLINA INTO SOUTHEAST PENNSYLVANIA AND SOUTHERN NEW JERSEY...AND ACROSS EASTERN SOUTH DAKOTA...CENTRAL/SOUTHERN MINNESOTA AND EXTREME NORTHWEST IOWA... ...SUMMARY... Scattered severe storms are most likely this afternoon and evening from eastern South Dakota into Minnesota with damaging winds and hail possible. Scattered thunderstorms producing damaging gusts are also expected across parts of the North Carolina Piedmont into the Mid-Atlantic vicinity. A developing tropical cyclone may also impact the Florida Keys and western Florida Peninsula. Meanwhile, isolated strong storms are possible across the southern High Plains. ...Mid-Atlantic Vicinity into SC/GA... An upper trough oriented from the lower Great Lakes/Ohio Valley to northern AL/GA will shift east toward the northern Appalachians and Mid-Atlantic vicinity through tonight. This will result in a belt of 25-35 kt southwesterly midlevel flow overspreading the NC/VA Piedmont, northward toward southern New England. A surface front will stall from eastern PA southwestward along the Blue Ridge Mountains and into north GA. To the east of this surface boundary, a very moist airmass will be in place, with dewpoints in the 70s F. This will aid in moderate destabilization, with MLCAPE values 1500-2000 J/kg common. A few pockets with higher instability are possible, but poor midlevel lapse rates will limit stronger destabilization on a large scale. Nevertheless, 25-35 kt effective shear magnitudes will support strong to severe thunderstorms. Thunderstorm clusters will be possible, and scattered wind damage is expected with this activity. A corridor of greater severe potential is expected from central NC into southeast PA/southern NJ, where greater storm coverage is expected along with increased potential for forward-propagating clusters. A Slight (level 2 of 5) risk has been included for this corridor. ...Eastern Dakotas/Upper Midwest... Moderate northwesterly mid/upper flow will overspread the region on the western periphery of a large Hudson Bay upper cyclone. A weak surface low is forecast to develop over central SD, with a warm front extending from southwest MN into central/eastern IA, and a cold front developing southward across northern MN and the Dakotas. A wedge of mid 60s to low 70s F dewpoints between these surface features will foster moderate to strong destabilization during the afternoon amid steep midlevel lapse rates. Vertically veering wind profiles and elongated/straight hodographs, along with effective shear magnitudes around 25-35 kt, should favor supercells. Damaging gusts and large to very large hail will be possible with this activity. Initial cellular activity may develop into a small MCS, transitioning the risk to mainly damaging winds during the evening. ...Southwest FL Peninsula... Per latest NHC guidance, Tropical Depression Four is forecast to become a tropical storm by this evening as the system tracks over the eastern Gulf of Mexico. Scattered thunderstorms will overspread the southern Peninsula, where low/mid level east/southeasterly flow will increase through the period. Sufficient low-level instability and 0-1 km SRH increasing to greater than 200 m2/s2 will support some risk for a couple of tornadoes. ...Southern High Plains... A convectively enhanced vorticity max is forecast to develop south across the central/southern High Plains vicinity this afternoon/evening. Vertically veering wind profiles will support rather robust effective shear magnitudes greater than 40 kt. Boundary-layer moisture will remain modest, but steep midlevel lapse rates will aid in at least weak destabilization (MLCAPE around 500-1000 J/kg) sufficient for high-based thunderstorm development. A deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow winds with any storms that develop. If any longer-lived cells can be maintained, isolated large hail is also possible. ..Leitman/Thornton.. 08/03/2024 Read more

SPC MD 1800

1 year ago
MD 1800 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEASTERN ARIZONA
Mesoscale Discussion 1800 NWS Storm Prediction Center Norman OK 0753 PM CDT Fri Aug 02 2024 Areas affected...southeastern Arizona Concerning...Severe potential...Watch unlikely Valid 030053Z - 030230Z Probability of Watch Issuance...5 percent SUMMARY...Marginal risk of strong to severe wind will continue through the evening. DISCUSSION...Thunderstorms ongoing across southeastern Arizona have shown strengthening in the last hour near and east of Tucson. Temperatures across much of the region are 100+ F with dew points in the low to mid 50s. Daytime heating has yielded MLCAPE around 500-1500 J/kg. The 00z sounding from Tucson depicts steep low to mid-level lapse rates, with characteristic inverted V and very dry surface conditions. Though flow is weak, large 40-50 degree dew point depressions and steep lapse rates will support risk for strong to severe gusts through the evening. ..Thornton/Smith.. 08/03/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC... LAT...LON 31911196 32531148 32931071 32940996 32740936 32490919 32180917 31830915 31480916 31390921 31350950 31400956 31321006 31311063 31361091 31411113 31541169 31661192 31911196 Read more

SPC MD 1798

1 year ago
MD 1798 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN MISSISSIPPI...CENTRAL ALABAMA
Mesoscale Discussion 1798 NWS Storm Prediction Center Norman OK 0551 PM CDT Fri Aug 02 2024 Areas affected...Eastern Mississippi...Central Alabama Concerning...Severe potential...Watch unlikely Valid 022251Z - 030115Z Probability of Watch Issuance...20 percent SUMMARY...Isolated severe gusts will be possible over the next few hours with the stronger cells from eastern Mississippi eastward across central Alabama. The severe threat is expected to remain marginal, and WW issuance is unlikely. DISCUSSION...The latest mosaic radar imagery shows an east-to-west oriented broken line of strong to locally severe thunderstorms extending from just north of Birmingham westward into eastern Mississippi. This line is located from near and just to the south of an axis of strong instability, where the RAP is estimated MLCAPE in the 3000 to 4500 J/kg range. In addition to the strong instability, the latest WSR-88D VWP at Birmingham has 0-6 km shear in the 20 to 25 kt range. This will support an isolated wind-damage threat as the cluster moves southeastward across far eastern Mississippi and central Alabama this evening. If the line can continue to organize a cold pool, then the potential for severe wind gusts could continue for a few more hours. ..Broyles/Smith.. 08/02/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BMX...MEG...JAN... LAT...LON 33708816 33848882 33838923 33638945 33268940 32958924 32748898 32618829 32618698 32718602 32918559 33208548 33568549 33748581 33638684 33708816 Read more

SPC Aug 3, 2024 0100 UTC Day 1 Convective Outlook

1 year ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 PM CDT Fri Aug 02 2024 Valid 030100Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL MISSISSIPPI/ALABAMA...THE CENTRAL HIGH PLAINS...AND SOUTHEAST ARIZONA... ...SUMMARY... Strong to locally severe storms remain possible this evening across parts of central Mississippi/Alabama, the central High Plains, and southeast Arizona. ...01z Update... Severe probabilities have been removed from much of the eastern U.S. While a strong storm or two may produce gusty winds from the central Appalachians to the Ohio Valley, weak vertical shear and a cooling/stabilizing boundary-layer will limit severe potential the remainder of the night. A storm or two may also produce strong gusts across parts of the Mid-Atlantic before moving offshore, but overall trends have decreased and severe potential is expected to be limited. A southward developing band of storms may continue to produce locally strong/damaging gusts across parts of central MS/AL for a few more hours this evening within a strongly unstable but weakly sheared environment. The Marginal Risk (level 1 of 5) has been reoriented and shifted a bit further south in AL to account for ongoing trends. Additional strong storms are possible for another few hours this evening across the central High Plains. The Marginal Risk (level 1 of 5) has been expanded eastward across a small part of NE to account for current radar trends. Isolated large hail and strong gusts are possible with this activity across western NE/northeast CO into extreme northwest KS. Other more isolated strong storms remain possible across southeast AZ for a few more hours as well. ..Leitman.. 08/03/2024 Read more

SPC Aug 3, 2024 0100 UTC Day 1 Convective Outlook

1 year ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 PM CDT Fri Aug 02 2024 Valid 030100Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL MISSISSIPPI/ALABAMA...THE CENTRAL HIGH PLAINS...AND SOUTHEAST ARIZONA... ...SUMMARY... Strong to locally severe storms remain possible this evening across parts of central Mississippi/Alabama, the central High Plains, and southeast Arizona. ...01z Update... Severe probabilities have been removed from much of the eastern U.S. While a strong storm or two may produce gusty winds from the central Appalachians to the Ohio Valley, weak vertical shear and a cooling/stabilizing boundary-layer will limit severe potential the remainder of the night. A storm or two may also produce strong gusts across parts of the Mid-Atlantic before moving offshore, but overall trends have decreased and severe potential is expected to be limited. A southward developing band of storms may continue to produce locally strong/damaging gusts across parts of central MS/AL for a few more hours this evening within a strongly unstable but weakly sheared environment. The Marginal Risk (level 1 of 5) has been reoriented and shifted a bit further south in AL to account for ongoing trends. Additional strong storms are possible for another few hours this evening across the central High Plains. The Marginal Risk (level 1 of 5) has been expanded eastward across a small part of NE to account for current radar trends. Isolated large hail and strong gusts are possible with this activity across western NE/northeast CO into extreme northwest KS. Other more isolated strong storms remain possible across southeast AZ for a few more hours as well. ..Leitman.. 08/03/2024 Read more

SPC Aug 3, 2024 0100 UTC Day 1 Convective Outlook

1 year ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 PM CDT Fri Aug 02 2024 Valid 030100Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL MISSISSIPPI/ALABAMA...THE CENTRAL HIGH PLAINS...AND SOUTHEAST ARIZONA... ...SUMMARY... Strong to locally severe storms remain possible this evening across parts of central Mississippi/Alabama, the central High Plains, and southeast Arizona. ...01z Update... Severe probabilities have been removed from much of the eastern U.S. While a strong storm or two may produce gusty winds from the central Appalachians to the Ohio Valley, weak vertical shear and a cooling/stabilizing boundary-layer will limit severe potential the remainder of the night. A storm or two may also produce strong gusts across parts of the Mid-Atlantic before moving offshore, but overall trends have decreased and severe potential is expected to be limited. A southward developing band of storms may continue to produce locally strong/damaging gusts across parts of central MS/AL for a few more hours this evening within a strongly unstable but weakly sheared environment. The Marginal Risk (level 1 of 5) has been reoriented and shifted a bit further south in AL to account for ongoing trends. Additional strong storms are possible for another few hours this evening across the central High Plains. The Marginal Risk (level 1 of 5) has been expanded eastward across a small part of NE to account for current radar trends. Isolated large hail and strong gusts are possible with this activity across western NE/northeast CO into extreme northwest KS. Other more isolated strong storms remain possible across southeast AZ for a few more hours as well. ..Leitman.. 08/03/2024 Read more

SPC Aug 3, 2024 0100 UTC Day 1 Convective Outlook

1 year ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 PM CDT Fri Aug 02 2024 Valid 030100Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL MISSISSIPPI/ALABAMA...THE CENTRAL HIGH PLAINS...AND SOUTHEAST ARIZONA... ...SUMMARY... Strong to locally severe storms remain possible this evening across parts of central Mississippi/Alabama, the central High Plains, and southeast Arizona. ...01z Update... Severe probabilities have been removed from much of the eastern U.S. While a strong storm or two may produce gusty winds from the central Appalachians to the Ohio Valley, weak vertical shear and a cooling/stabilizing boundary-layer will limit severe potential the remainder of the night. A storm or two may also produce strong gusts across parts of the Mid-Atlantic before moving offshore, but overall trends have decreased and severe potential is expected to be limited. A southward developing band of storms may continue to produce locally strong/damaging gusts across parts of central MS/AL for a few more hours this evening within a strongly unstable but weakly sheared environment. The Marginal Risk (level 1 of 5) has been reoriented and shifted a bit further south in AL to account for ongoing trends. Additional strong storms are possible for another few hours this evening across the central High Plains. The Marginal Risk (level 1 of 5) has been expanded eastward across a small part of NE to account for current radar trends. Isolated large hail and strong gusts are possible with this activity across western NE/northeast CO into extreme northwest KS. Other more isolated strong storms remain possible across southeast AZ for a few more hours as well. ..Leitman.. 08/03/2024 Read more

SPC Aug 3, 2024 0100 UTC Day 1 Convective Outlook

1 year ago
SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0737 PM CDT Fri Aug 02 2024 Valid 030100Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL MISSISSIPPI/ALABAMA...THE CENTRAL HIGH PLAINS...AND SOUTHEAST ARIZONA... ...SUMMARY... Strong to locally severe storms remain possible this evening across parts of central Mississippi/Alabama, the central High Plains, and southeast Arizona. ...01z Update... Severe probabilities have been removed from much of the eastern U.S. While a strong storm or two may produce gusty winds from the central Appalachians to the Ohio Valley, weak vertical shear and a cooling/stabilizing boundary-layer will limit severe potential the remainder of the night. A storm or two may also produce strong gusts across parts of the Mid-Atlantic before moving offshore, but overall trends have decreased and severe potential is expected to be limited. A southward developing band of storms may continue to produce locally strong/damaging gusts across parts of central MS/AL for a few more hours this evening within a strongly unstable but weakly sheared environment. The Marginal Risk (level 1 of 5) has been reoriented and shifted a bit further south in AL to account for ongoing trends. Additional strong storms are possible for another few hours this evening across the central High Plains. The Marginal Risk (level 1 of 5) has been expanded eastward across a small part of NE to account for current radar trends. Isolated large hail and strong gusts are possible with this activity across western NE/northeast CO into extreme northwest KS. Other more isolated strong storms remain possible across southeast AZ for a few more hours as well. ..Leitman.. 08/03/2024 Read more
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