Severe Storms

MD 1995 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST ALABAMA...NORTHWEST GEORGIA...AND PORTIONS OF SOUTHEAST TENNESSEE
Mesoscale Discussion 1995 NWS Storm Prediction Center Norman OK 0250 PM CDT Wed Aug 20 2025 Areas affected...northeast Alabama...northwest Georgia...and portions of southeast Tennessee Concerning...Severe potential...Watch unlikely Valid 201950Z - 202115Z Probability of Watch Issuance...5 percent SUMMARY...Isolated severe wind gusts are possible this afternoon. DISCUSSION...A cluster of storms has developed across southeast Tennessee. As these storms, and associated outflow, move south, they will encounter increasing instability with temperatures in the upper 80s to low 90s and dewpoints in the mid 70s yielding 2500 J/kg MLCAPE. Despite the favorable thermodynamic environment, shear is quite weak (flow less than 20 knots in the entire troposphere on the HTX VWP). This weak shear will likely result in mostly unorganized storms with strong outflow. Stronger cores/water loading will support the threat for microbursts, particularly where boundary collisions occur. Expect the greatest severe threat to shift south through the remainder of the afternoon and into the evening as outflow continues to progress south. ..Bentley/Gleason.. 08/20/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MRX...FFC...OHX...BMX...HUN... LAT...LON 34108738 35258617 35718500 35568432 34848410 34008453 33348479 32868617 33268694 34108738 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 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0258 PM CDT Wed Aug 20 2025 Valid 202000Z - 211200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF TEXAS INTO THE LOWER MISSISSIPPI VALLEY/SOUTHEAST...AND THE NORTHERN PLAINS... ...SUMMARY... Scattered thunderstorms from Texas across the Lower Mississippi Valley and Southeast may pose a risk for localized damaging wind gusts this afternoon and evening. Isolated severe thunderstorms may also occur across parts of central/eastern Montana and northern North Dakota, mainly this evening and overnight. ...20z Update... Changes were made to clear the Marginal Risk across portions of central Texas where thunderstorms and outflow have moved southward. The Marginal Risk was expanded across the Southeast into portions of northwest Georgia and eastern Alabama. A cluster of thunderstorms continues to sag southward into this region, with cores exhibiting some uptick in intensity. See MCD#1995. Otherwise, the outlook remains on track with no additional changes needed. See previous discussion below for more information. ..Thornton.. 08/20/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed Aug 20 2025/ ...Texas into the Lower Mississippi Valley and Southeast... A convectively reinforced front/outflow boundary from earlier/ongoing convection should once again provide a focus for renewed convective development this afternoon from parts of west-central TX eastward into the lower MS Valley and Southeast. Mid-level flow and related deep-layer shear are expected to remain weak, which should generally limit thunderstorm organization. Still, a moderately to strongly unstable environment will exist along/south of the front with continued daytime heating, with scattered to numerous thunderstorms likely. Similar to yesterday, wet microbursts from convective downdrafts may produce isolated damaging winds as low-level lapse rates become steepened. These thunderstorms should weaken through the evening with the loss of daytime heating. ...Northern Plains... The northern Plains will be influenced by late-day/overnight mid-level height falls as a shortwave trough moves eastward from the Canadian/northern Rockies, with a related cold front moving across central/eastern MT into ND tonight. A narrow corridor of moderate to strong instability will likely develop along/ahead of the cold front, and near a pre-frontal surface trough. But, warm mid-level temperatures and a capped airmass will likely exist along/south of the international border, which should inhibit robust convective development for much of the day. One exception may be in the post-frontal environment across eastern MT this evening/tonight. The environment here should be conducive to isolated severe thunderstorms capable of producing both large hail and severe gusts. While the risk for severe thunderstorms appears more conditional into ND where stronger destabilization is expected, isolated convective development may still occur across northwestern ND in proximity to the surface low/front late this afternoon, and perhaps more so this evening/overnight. Should this occur, forecast soundings indicate the environment would support isolated supercell development with a related hail/wind threat. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Wed Aug 20 2025 Valid 221200Z - 231200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Strong to locally severe thunderstorms are possible Friday from parts of the central and northern High Plains into the Upper Midwest. ...Northern/Central High Plains to Upper Midwest... An upper cyclone over the Canadian Prairies and its attendant trough will develop southeast across portions of the northern/central Plains and Upper Midwest/Great Lakes on Friday. At the surface, a cold front will develop south/southeast across the region. A seasonally moist airmass will be in place near and ahead of the front. A narrow corridor of 1000-3000 J/kg MLCAPE is forecast ahead of the front from the WY/CO High Plains eastward across parts of NE and northeast into southern MN and northern/central WI. Isolated to widely scattered thunderstorms are expected to develop during the afternoon across portions of WI/MN and the U.P. of MI. closer to the surface low over Ontario. Vertical shear is expected to remain modest, with stronger shear likely trailing the cold front. Nevertheless, steepened low-level lapse rates where stronger heating occurs could support sporadic strong to severe gusts. Additional storms are expected to develop in the post-frontal upslope regime across parts of eastern WY and northeast CO during the late afternoon/evening. This activity may eventually become a forward propagating cluster across NE during the nighttime hours as the surface cold front develops southward toward the KS border. Forecast soundings indicated sufficient deep shear and elongated/straight hodographs will be present amid steep midlevel lapse rates. Isolated large hail may be possible initially, with an increasing chance for isolated damaging gusts if sufficient clustering can occur further east into NE and vicinity. ..Leitman.. 08/20/2025 Read more