Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1107 AM CDT Thu Aug 15 2024 Valid 151700Z - 161200Z The previous forecast remains on track. The early-morning round of convection has largely ended with a mix of wet/dry thunderstorms observed based on lighting data and MRMS QPE. A second round of thunderstorms remains likely this afternoon along and east of the OR Cascades into western ID under the upper low. Morning guidance suggests thunderstorms this afternoon will have a higher probability for wetting rainfall compared to convection that occurred over the previous 12 hours. However, areas that did not receive appreciable overnight rain have likely maintained receptive fuels that should support fire starts from lightning strikes on the periphery of heavier precipitation cores. Given this concern, along with the potential for numerous lightning strikes across east-central OR, the risk area has been maintained. See the previous discussion below regarding additional, but low-end, fire weather concerns. ..Moore.. 08/15/2024 .PREV DISCUSSION... /ISSUED 0111 AM CDT Thu Aug 15 2024/ ...Synopsis... A mid-level trough is forecast to move across the Northwest, bringing two different rounds of a mix of scattered wet/dry thunderstorms to portions of Oregon and Idaho. ...Dry Thunderstorms... Overnight elevated convection is expected to persist into beginning of the forecast period over Oregon. However, the greatest chance for thunderstorm development will be later in the afternoon (20-21Z), when a mix of scattered wet/dry thunderstorms is forecast to develop over south-central Oregon and progress northeastward into western Idaho. Fuels guidance shows ERCs are at or exceeding the 90th percentile, so even though PWAT values of 0.6-0.9 inches and relatively slow storm motions of 20 kts will support at least some wetting rainfall, lightning-based ignitions will still be possible. ...Dry/Windy... Localized elevated conditions are possible across eastern Nevada and western Utah, but will mostly be confined to diurnally/terrain-driven corridors. These conditions also overlap with recent wetting rainfall and fuels that are only modestly dry. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Thu Aug 15 14:00:02 UTC 2024.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Aug 15 2024 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE OZARKS...LOWER MISSOURI VALLEY...AND ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Central Plains to the Mid Mississippi Valley... Morning water-vapor imagery shows a series of embedded disturbances rotating through a larger-scale trough centered over the northern Great Plains. A notable shortwave trough is located near the WY/NE/SD vicinity and this feature will move east reaching the Upper Great Lakes by Friday morning. A lead convectively augmented disturbance is moving east across the mid MS Valley this morning, and it will move east into the southern Great Lakes and weaken during the day. Broken bands of showers/thunderstorms associated with this lead impulse will progress east this morning and move into a less unstable airmass across the Wabash Valley. Some rejuvenation of storms is possible later today on the southern portion of the trailing outflow near the MS-OH River confluence westward into the Ozarks. Appreciable uncertainty exists at this time on the intensity/coverage of storms in the aforementioned corridor. Nonetheless, heating of a moist airmass will potentially yield an environment favorable for at least isolated to widely scattered storms capable of a wind/hail threat. In wake of the early day cloud debris and overnight storm activity, strong boundary-layer heating is expected across much of the Plains into portions of the mid MS Valley. As a result, strong buoyancy will develop along the eastern edge of this steeper lapse-rate plume. Model guidance suggests very strong instability (MLCAPE >3000 J/kg) will probably develop by mid-late afternoon from portions of eastern KS/MO into southern IA. Thunderstorms may focus along a synoptic front that will arc from southeast MN-eastern IA-northern MO-southeast KS-northern OK by late afternoon. Some guidance (i.e., 00Z MPAS and recent HRRR runs) indicates lower storm coverage until later this evening across the lower MO Valley/mid MS Valley portion of the Slight Risk. Regardless, deep-layer shear should be adequate for supercells and organized clusters and wind/hail can be expected with the most robust updrafts. High-based thunderstorms are also expected to develop along the trailing boundary into the southern Plains where surface temperatures will easily rise through the upper 90s to near 100F. The stronger evaporatively cooled downdrafts will potentially result in severe gusts before this activity diminishes by mid-late evening. ...New England... Upper troughing will hold across New England today with cool mid-level temperatures and modest northerly flow at 500mb. Strong boundary-layer heating will allow convective temperatures to be breached by 19z and scattered convection is expected to develop within a sheared environment that favors robust multi-cell updrafts. Some of this activity could generate strong gusts and marginally severe hail. Convection will be diurnally driven and should weaken with loss of daytime heating. ...Northern Rockies... A mid- to upper-level trough over the Pacific Northwest will gradually move northeast impinging on the northern Rockies by afternoon. The favorable timing of large-scale ascent and diurnal destabilization will yield scattered to numerous thunderstorms developing from the Upper Snake Valley north-northwestward into north-central ID and western MT by early evening. Forecast soundings show steep lapse rates and potentially favorable for localized severe gusts with the stronger thunderstorm cores and outflow-dominant clusters. ..Smith.. 08/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Aug 15 2024 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE OZARKS...LOWER MISSOURI VALLEY...AND ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Central Plains to the Mid Mississippi Valley... Morning water-vapor imagery shows a series of embedded disturbances rotating through a larger-scale trough centered over the northern Great Plains. A notable shortwave trough is located near the WY/NE/SD vicinity and this feature will move east reaching the Upper Great Lakes by Friday morning. A lead convectively augmented disturbance is moving east across the mid MS Valley this morning, and it will move east into the southern Great Lakes and weaken during the day. Broken bands of showers/thunderstorms associated with this lead impulse will progress east this morning and move into a less unstable airmass across the Wabash Valley. Some rejuvenation of storms is possible later today on the southern portion of the trailing outflow near the MS-OH River confluence westward into the Ozarks. Appreciable uncertainty exists at this time on the intensity/coverage of storms in the aforementioned corridor. Nonetheless, heating of a moist airmass will potentially yield an environment favorable for at least isolated to widely scattered storms capable of a wind/hail threat. In wake of the early day cloud debris and overnight storm activity, strong boundary-layer heating is expected across much of the Plains into portions of the mid MS Valley. As a result, strong buoyancy will develop along the eastern edge of this steeper lapse-rate plume. Model guidance suggests very strong instability (MLCAPE >3000 J/kg) will probably develop by mid-late afternoon from portions of eastern KS/MO into southern IA. Thunderstorms may focus along a synoptic front that will arc from southeast MN-eastern IA-northern MO-southeast KS-northern OK by late afternoon. Some guidance (i.e., 00Z MPAS and recent HRRR runs) indicates lower storm coverage until later this evening across the lower MO Valley/mid MS Valley portion of the Slight Risk. Regardless, deep-layer shear should be adequate for supercells and organized clusters and wind/hail can be expected with the most robust updrafts. High-based thunderstorms are also expected to develop along the trailing boundary into the southern Plains where surface temperatures will easily rise through the upper 90s to near 100F. The stronger evaporatively cooled downdrafts will potentially result in severe gusts before this activity diminishes by mid-late evening. ...New England... Upper troughing will hold across New England today with cool mid-level temperatures and modest northerly flow at 500mb. Strong boundary-layer heating will allow convective temperatures to be breached by 19z and scattered convection is expected to develop within a sheared environment that favors robust multi-cell updrafts. Some of this activity could generate strong gusts and marginally severe hail. Convection will be diurnally driven and should weaken with loss of daytime heating. ...Northern Rockies... A mid- to upper-level trough over the Pacific Northwest will gradually move northeast impinging on the northern Rockies by afternoon. The favorable timing of large-scale ascent and diurnal destabilization will yield scattered to numerous thunderstorms developing from the Upper Snake Valley north-northwestward into north-central ID and western MT by early evening. Forecast soundings show steep lapse rates and potentially favorable for localized severe gusts with the stronger thunderstorm cores and outflow-dominant clusters. ..Smith.. 08/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Aug 15 2024 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE OZARKS...LOWER MISSOURI VALLEY...AND ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Central Plains to the Mid Mississippi Valley... Morning water-vapor imagery shows a series of embedded disturbances rotating through a larger-scale trough centered over the northern Great Plains. A notable shortwave trough is located near the WY/NE/SD vicinity and this feature will move east reaching the Upper Great Lakes by Friday morning. A lead convectively augmented disturbance is moving east across the mid MS Valley this morning, and it will move east into the southern Great Lakes and weaken during the day. Broken bands of showers/thunderstorms associated with this lead impulse will progress east this morning and move into a less unstable airmass across the Wabash Valley. Some rejuvenation of storms is possible later today on the southern portion of the trailing outflow near the MS-OH River confluence westward into the Ozarks. Appreciable uncertainty exists at this time on the intensity/coverage of storms in the aforementioned corridor. Nonetheless, heating of a moist airmass will potentially yield an environment favorable for at least isolated to widely scattered storms capable of a wind/hail threat. In wake of the early day cloud debris and overnight storm activity, strong boundary-layer heating is expected across much of the Plains into portions of the mid MS Valley. As a result, strong buoyancy will develop along the eastern edge of this steeper lapse-rate plume. Model guidance suggests very strong instability (MLCAPE >3000 J/kg) will probably develop by mid-late afternoon from portions of eastern KS/MO into southern IA. Thunderstorms may focus along a synoptic front that will arc from southeast MN-eastern IA-northern MO-southeast KS-northern OK by late afternoon. Some guidance (i.e., 00Z MPAS and recent HRRR runs) indicates lower storm coverage until later this evening across the lower MO Valley/mid MS Valley portion of the Slight Risk. Regardless, deep-layer shear should be adequate for supercells and organized clusters and wind/hail can be expected with the most robust updrafts. High-based thunderstorms are also expected to develop along the trailing boundary into the southern Plains where surface temperatures will easily rise through the upper 90s to near 100F. The stronger evaporatively cooled downdrafts will potentially result in severe gusts before this activity diminishes by mid-late evening. ...New England... Upper troughing will hold across New England today with cool mid-level temperatures and modest northerly flow at 500mb. Strong boundary-layer heating will allow convective temperatures to be breached by 19z and scattered convection is expected to develop within a sheared environment that favors robust multi-cell updrafts. Some of this activity could generate strong gusts and marginally severe hail. Convection will be diurnally driven and should weaken with loss of daytime heating. ...Northern Rockies... A mid- to upper-level trough over the Pacific Northwest will gradually move northeast impinging on the northern Rockies by afternoon. The favorable timing of large-scale ascent and diurnal destabilization will yield scattered to numerous thunderstorms developing from the Upper Snake Valley north-northwestward into north-central ID and western MT by early evening. Forecast soundings show steep lapse rates and potentially favorable for localized severe gusts with the stronger thunderstorm cores and outflow-dominant clusters. ..Smith.. 08/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Aug 15 2024 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE OZARKS...LOWER MISSOURI VALLEY...AND ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Central Plains to the Mid Mississippi Valley... Morning water-vapor imagery shows a series of embedded disturbances rotating through a larger-scale trough centered over the northern Great Plains. A notable shortwave trough is located near the WY/NE/SD vicinity and this feature will move east reaching the Upper Great Lakes by Friday morning. A lead convectively augmented disturbance is moving east across the mid MS Valley this morning, and it will move east into the southern Great Lakes and weaken during the day. Broken bands of showers/thunderstorms associated with this lead impulse will progress east this morning and move into a less unstable airmass across the Wabash Valley. Some rejuvenation of storms is possible later today on the southern portion of the trailing outflow near the MS-OH River confluence westward into the Ozarks. Appreciable uncertainty exists at this time on the intensity/coverage of storms in the aforementioned corridor. Nonetheless, heating of a moist airmass will potentially yield an environment favorable for at least isolated to widely scattered storms capable of a wind/hail threat. In wake of the early day cloud debris and overnight storm activity, strong boundary-layer heating is expected across much of the Plains into portions of the mid MS Valley. As a result, strong buoyancy will develop along the eastern edge of this steeper lapse-rate plume. Model guidance suggests very strong instability (MLCAPE >3000 J/kg) will probably develop by mid-late afternoon from portions of eastern KS/MO into southern IA. Thunderstorms may focus along a synoptic front that will arc from southeast MN-eastern IA-northern MO-southeast KS-northern OK by late afternoon. Some guidance (i.e., 00Z MPAS and recent HRRR runs) indicates lower storm coverage until later this evening across the lower MO Valley/mid MS Valley portion of the Slight Risk. Regardless, deep-layer shear should be adequate for supercells and organized clusters and wind/hail can be expected with the most robust updrafts. High-based thunderstorms are also expected to develop along the trailing boundary into the southern Plains where surface temperatures will easily rise through the upper 90s to near 100F. The stronger evaporatively cooled downdrafts will potentially result in severe gusts before this activity diminishes by mid-late evening. ...New England... Upper troughing will hold across New England today with cool mid-level temperatures and modest northerly flow at 500mb. Strong boundary-layer heating will allow convective temperatures to be breached by 19z and scattered convection is expected to develop within a sheared environment that favors robust multi-cell updrafts. Some of this activity could generate strong gusts and marginally severe hail. Convection will be diurnally driven and should weaken with loss of daytime heating. ...Northern Rockies... A mid- to upper-level trough over the Pacific Northwest will gradually move northeast impinging on the northern Rockies by afternoon. The favorable timing of large-scale ascent and diurnal destabilization will yield scattered to numerous thunderstorms developing from the Upper Snake Valley north-northwestward into north-central ID and western MT by early evening. Forecast soundings show steep lapse rates and potentially favorable for localized severe gusts with the stronger thunderstorm cores and outflow-dominant clusters. ..Smith.. 08/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Aug 15 2024 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE OZARKS...LOWER MISSOURI VALLEY...AND ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Central Plains to the Mid Mississippi Valley... Morning water-vapor imagery shows a series of embedded disturbances rotating through a larger-scale trough centered over the northern Great Plains. A notable shortwave trough is located near the WY/NE/SD vicinity and this feature will move east reaching the Upper Great Lakes by Friday morning. A lead convectively augmented disturbance is moving east across the mid MS Valley this morning, and it will move east into the southern Great Lakes and weaken during the day. Broken bands of showers/thunderstorms associated with this lead impulse will progress east this morning and move into a less unstable airmass across the Wabash Valley. Some rejuvenation of storms is possible later today on the southern portion of the trailing outflow near the MS-OH River confluence westward into the Ozarks. Appreciable uncertainty exists at this time on the intensity/coverage of storms in the aforementioned corridor. Nonetheless, heating of a moist airmass will potentially yield an environment favorable for at least isolated to widely scattered storms capable of a wind/hail threat. In wake of the early day cloud debris and overnight storm activity, strong boundary-layer heating is expected across much of the Plains into portions of the mid MS Valley. As a result, strong buoyancy will develop along the eastern edge of this steeper lapse-rate plume. Model guidance suggests very strong instability (MLCAPE >3000 J/kg) will probably develop by mid-late afternoon from portions of eastern KS/MO into southern IA. Thunderstorms may focus along a synoptic front that will arc from southeast MN-eastern IA-northern MO-southeast KS-northern OK by late afternoon. Some guidance (i.e., 00Z MPAS and recent HRRR runs) indicates lower storm coverage until later this evening across the lower MO Valley/mid MS Valley portion of the Slight Risk. Regardless, deep-layer shear should be adequate for supercells and organized clusters and wind/hail can be expected with the most robust updrafts. High-based thunderstorms are also expected to develop along the trailing boundary into the southern Plains where surface temperatures will easily rise through the upper 90s to near 100F. The stronger evaporatively cooled downdrafts will potentially result in severe gusts before this activity diminishes by mid-late evening. ...New England... Upper troughing will hold across New England today with cool mid-level temperatures and modest northerly flow at 500mb. Strong boundary-layer heating will allow convective temperatures to be breached by 19z and scattered convection is expected to develop within a sheared environment that favors robust multi-cell updrafts. Some of this activity could generate strong gusts and marginally severe hail. Convection will be diurnally driven and should weaken with loss of daytime heating. ...Northern Rockies... A mid- to upper-level trough over the Pacific Northwest will gradually move northeast impinging on the northern Rockies by afternoon. The favorable timing of large-scale ascent and diurnal destabilization will yield scattered to numerous thunderstorms developing from the Upper Snake Valley north-northwestward into north-central ID and western MT by early evening. Forecast soundings show steep lapse rates and potentially favorable for localized severe gusts with the stronger thunderstorm cores and outflow-dominant clusters. ..Smith.. 08/15/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0743 AM CDT Thu Aug 15 2024 Valid 151300Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE OZARKS...LOWER MISSOURI VALLEY...AND ILLINOIS... ...SUMMARY... Scattered severe thunderstorms are possible across parts of the Midwest through tonight. Severe gusts capable of wind damage and large hail are the primary risks with the stronger thunderstorms. ...Central Plains to the Mid Mississippi Valley... Morning water-vapor imagery shows a series of embedded disturbances rotating through a larger-scale trough centered over the northern Great Plains. A notable shortwave trough is located near the WY/NE/SD vicinity and this feature will move east reaching the Upper Great Lakes by Friday morning. A lead convectively augmented disturbance is moving east across the mid MS Valley this morning, and it will move east into the southern Great Lakes and weaken during the day. Broken bands of showers/thunderstorms associated with this lead impulse will progress east this morning and move into a less unstable airmass across the Wabash Valley. Some rejuvenation of storms is possible later today on the southern portion of the trailing outflow near the MS-OH River confluence westward into the Ozarks. Appreciable uncertainty exists at this time on the intensity/coverage of storms in the aforementioned corridor. Nonetheless, heating of a moist airmass will potentially yield an environment favorable for at least isolated to widely scattered storms capable of a wind/hail threat. In wake of the early day cloud debris and overnight storm activity, strong boundary-layer heating is expected across much of the Plains into portions of the mid MS Valley. As a result, strong buoyancy will develop along the eastern edge of this steeper lapse-rate plume. Model guidance suggests very strong instability (MLCAPE >3000 J/kg) will probably develop by mid-late afternoon from portions of eastern KS/MO into southern IA. Thunderstorms may focus along a synoptic front that will arc from southeast MN-eastern IA-northern MO-southeast KS-northern OK by late afternoon. Some guidance (i.e., 00Z MPAS and recent HRRR runs) indicates lower storm coverage until later this evening across the lower MO Valley/mid MS Valley portion of the Slight Risk. Regardless, deep-layer shear should be adequate for supercells and organized clusters and wind/hail can be expected with the most robust updrafts. High-based thunderstorms are also expected to develop along the trailing boundary into the southern Plains where surface temperatures will easily rise through the upper 90s to near 100F. The stronger evaporatively cooled downdrafts will potentially result in severe gusts before this activity diminishes by mid-late evening. ...New England... Upper troughing will hold across New England today with cool mid-level temperatures and modest northerly flow at 500mb. Strong boundary-layer heating will allow convective temperatures to be breached by 19z and scattered convection is expected to develop within a sheared environment that favors robust multi-cell updrafts. Some of this activity could generate strong gusts and marginally severe hail. Convection will be diurnally driven and should weaken with loss of daytime heating. ...Northern Rockies... A mid- to upper-level trough over the Pacific Northwest will gradually move northeast impinging on the northern Rockies by afternoon. The favorable timing of large-scale ascent and diurnal destabilization will yield scattered to numerous thunderstorms developing from the Upper Snake Valley north-northwestward into north-central ID and western MT by early evening. Forecast soundings show steep lapse rates and potentially favorable for localized severe gusts with the stronger thunderstorm cores and outflow-dominant clusters. ..Smith.. 08/15/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CDT Thu Aug 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... As an upper trough moves slowly eastward over the eastern CONUS, an isolated severe threat may continue on Day 4/Sunday across parts of the Mid-Atlantic into the Southeast along/ahead of a cold front. However, the potential stabilizing effects of prior convection, along with generally modest deep-layer shear, render low confidence in a more organized severe/damaging wind threat on Sunday. Lower severe potential is anticipated across the eastern states on Day 5/Monday as the upper trough progresses eastward and the cold front moves mostly offshore. Upper ridging will likely remain prominent across much of the Rockies and Plains through at least early next week, while an upper trough/low generally remains centered off the coast of the Pacific Northwest. Some chance for severe thunderstorms may exist over interior portions of the Northwest into parts of the northern Rockies/Plains and perhaps Upper Midwest next week. But, predictability of various mid-level perturbations that may encourage robust thunderstorms remains low at this extended time frame. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CDT Thu Aug 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... As an upper trough moves slowly eastward over the eastern CONUS, an isolated severe threat may continue on Day 4/Sunday across parts of the Mid-Atlantic into the Southeast along/ahead of a cold front. However, the potential stabilizing effects of prior convection, along with generally modest deep-layer shear, render low confidence in a more organized severe/damaging wind threat on Sunday. Lower severe potential is anticipated across the eastern states on Day 5/Monday as the upper trough progresses eastward and the cold front moves mostly offshore. Upper ridging will likely remain prominent across much of the Rockies and Plains through at least early next week, while an upper trough/low generally remains centered off the coast of the Pacific Northwest. Some chance for severe thunderstorms may exist over interior portions of the Northwest into parts of the northern Rockies/Plains and perhaps Upper Midwest next week. But, predictability of various mid-level perturbations that may encourage robust thunderstorms remains low at this extended time frame. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CDT Thu Aug 15 2024 Valid 181200Z - 231200Z ...DISCUSSION... As an upper trough moves slowly eastward over the eastern CONUS, an isolated severe threat may continue on Day 4/Sunday across parts of the Mid-Atlantic into the Southeast along/ahead of a cold front. However, the potential stabilizing effects of prior convection, along with generally modest deep-layer shear, render low confidence in a more organized severe/damaging wind threat on Sunday. Lower severe potential is anticipated across the eastern states on Day 5/Monday as the upper trough progresses eastward and the cold front moves mostly offshore. Upper ridging will likely remain prominent across much of the Rockies and Plains through at least early next week, while an upper trough/low generally remains centered off the coast of the Pacific Northwest. Some chance for severe thunderstorms may exist over interior portions of the Northwest into parts of the northern Rockies/Plains and perhaps Upper Midwest next week. But, predictability of various mid-level perturbations that may encourage robust thunderstorms remains low at this extended time frame. Read more