Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Mon Aug 19 2024 Valid 192000Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN AND CENTRAL HIGH PLAINS...AND OVER WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana into tonight. Large hail and severe gusts are the primary hazards. ...20Z Update... Within the Slight Risk area over the central High Plains, 15-percent wind probabilities were added over parts of eastern CO. Here, ample diurnal heating/steepening low-level lapse rates has increased confidence in a slightly greater concentration of severe wind gusts -- especially with any clusters that evolve eastward into this evening. For more details, reference MCD #1956 and Severe Thunderstorm Watch #639. Farther north, the Slight Risk was expanded slightly eastward into western ND, where filtered diurnal heating and an eventual increase in the low-level jet should favor localized upscale growth and a continued severe-wind risk into tonight. See MCD #1958 for additional details. From portions of the Northeast into the Mid-Atlantic, scattered thunderstorms will continue tracking eastward along/ahead of a cold front through the afternoon, posing a risk of locally damaging wind gusts. The Marginal Risk was trimmed slightly behind the front in the Northeast. For details, see MCDs #1955/1957. ..Weinman.. 08/19/2024 .PREV DISCUSSION... /ISSUED 1117 AM CDT Mon Aug 19 2024/ ...High Plains... Moderately strong westerly mid-level winds are present today from MT to CO, with several weak perturbations noted on water vapor imagery within the flow. Steep mid-level lapse rates and dewpoints in the 60s will lead to a narrow corridor of favorable CAPE later today for strong/severe thunderstorm development. Clusters of convection will form over the mountains and foothills of CO/WY and spread eastward into the higher instability axis. Other areas of storms are expected to develop over the Black Hills, and across parts of eastern MT. Large hail is the main concern with these storms, although the risk of isolated damaging wind will also increase during the late afternoon and evening as outflows congeal. ...Western MT... 12z model guidance continues to agree on the development of scattered thunderstorms this afternoon over the mountains of western MT. This region will be on the eastern fringe of stronger flow aloft, and where full sunshine will aid in destabilization and steepening of low-level lapse rates. As storms move off the higher terrain, merging outflows may result in strong/damaging wind gusts in the more organized storm clusters. One mitigating factor for severe in this region would be if the persistent cloud cover east of the mountains limits destabilization. ...Southeast VA/Northeast NC... Strong daytime heating is occurring today over parts of southeast VA and northeast NC, where dewpoints in the upper 60s and 70s will yield MLCAPE values around 2000 J/kg. Scattered afternoon thunderstorms are expected. Low and mid-level winds are relatively weak today, suggesting that storms will struggle to organize. However, given the extent of heating, a few cells may occasionally pose a risk of gusty winds through the early evening. ...New England... An upper trough is moving across the Northeast US today, with the associated surface cold front tracking eastward across much of New England this afternoon. Scattered thunderstorms are expected along the front. Visible satellite imagery suggest considerable cloud cover over this region, limiting daytime heating and suppressing steeper low-level lapse rates. This should lessen the overall severe threat today. Nevertheless, a few storms could produce gusty winds and/or hail. Read more

WW 0639 Status Updates
STATUS FOR WATCH 0639 HAS NOT BEEN ISSUED YET Read more

WW 0639 Status Updates
STATUS FOR WATCH 0639 HAS NOT BEEN ISSUED YET Read more

WW 0639 Status Updates
STATUS FOR WATCH 0639 HAS NOT BEEN ISSUED YET Read more

WW 0639 Status Updates
STATUS FOR WATCH 0639 HAS NOT BEEN ISSUED YET Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE MONTANA/NORTH DAKOTA BORDER VICINITY... ...SUMMARY... Widely scattered to potentially scattered storms will be possible on Wednesday across parts of the northern High Plains. Severe winds and large hail could occur. Marginally severe storms will be possible westward into central Montana and southward into the central High Plains. ...Synopsis... Broad cyclonic flow will continue across portions of the Western U.S. A mid-level shortwave trough is expected to lift northeastward through the northern Rockies into the northern High Plains late Wednesday afternoon into the evening. A surface low will deepen near the Montana/North Dakota border with a lee trough extending into the central High Plains. ...Montana into North Dakota... Convection is likely to form within the higher terrain of southwest Montana. Deep-layer shear will be strong, but buoyancy will be weak to modest. Strong/severe wind gusts and isolated large hail are possible. Greater uncertainty exists in the exact scenario for the Montana/North Dakota border vicinity. With the surface low deepening, a few storms could initiate during the mid/late-afternoon. These storms would have a greater chance at maintaining a supercellular mode. Severe wind gusts and large hail would be the main hazards with this scenario. However, mid-level heights will be mostly neutral through the day before modest falls occur by early evening and low-level forcing will be limited as well. A second possibility is for activity in Montana to move into the border region during early/mid-evening. Severe winds would be the primary hazard with what would likely be outflow-dominant storms. Given the late timing of these storms, it is not certain how much severe coverage there would be. The 15% severe probability area will be maintained this cycle with guidance hopefully providing more clarity in the coming days. ...Black Hills into central High Plains... Isolated to widely scattered storms are possible within the lee trough. Shear will be weaker with southern extent. A few severe gusts and marginally severe hail could occur with the strongest storms during the afternoon. ...Mid-Missouri Valley... Some convection may be ongoing in eastern South Dakota into southern Minnesota early in the period. Some outflow can be expected with this activity. With the MCV, flow aloft will be enhanced into eastern Nebraska. While a conditional threat for a strong/severe storm exists, low/mid-level forcing will be weak and storm initiation is far from certain. ..Wendt.. 08/19/2024 Read more