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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0250 PM CDT Mon Sep 02 2024 Valid 022000Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHERN GREAT BASIN AND THE NORTHWEST... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the interior Pacific Northwest may be capable of occasional strong to severe wind gusts this afternoon and evening. ...20Z Update... Minor adjustments were made to the general thunderstorm area to account for current observed trends. The remainder of the forecast is unchanged. See the previous discussion for additional details. ..Wendt.. 09/02/2024 .PREV DISCUSSION... /ISSUED 1118 AM CDT Mon Sep 02 2024/ ...Interior Pacific Northwest into the Northern Great Basin/Rockies... Water-vapor imagery this morning shows a closed low near the northern CA/southern OR coast. This upper feature will move east through OR and be situated along the OR/ID border by daybreak Tuesday. A belt of stronger flow (30-50 kt 500-mb winds) will move through the base of the larger-scale mid-level trough and overspread northern NV into southwestern ID and eastern OR this afternoon into the early evening. Large-scale ascent associated with the upper disturbance and the development of weak buoyancy (mainly via heating), will facilitate the development of isolated to scattered high-based thunderstorms beginning later this afternoon and persisting into the evening. Forecast soundings show large surface temperature-dewpoint spreads (50 degrees F) with 9+ degrees C lapse rates into the mid levels and a dry sub-cloud layer. Evaporative cooling of the more intense downdrafts will probably yield a risk for isolated 60-70 mph gusts before weakening later this evening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/02/2024 .PREV DISCUSSION... /ISSUED 0218 AM CDT Mon Sep 02 2024/ ...Synopsis... Fire weather concerns will continue into Tuesday as an upper wave (currently moving onshore along the northern CA coast) translates east across the northern Rockies. However, fire weather conditions are not expected to be as intense or widespread as compared to Monday across on either side of the continental divide. ...Nevada into Idaho... Portions of northeast NV and central ID are forecast to remain within the dry slot of the maturing upper-level low. This will maintain clear skies/warm conditions across the region, but will also support broad scale subsidence/drying and windy conditions across the region. Regional orographic influences - namely the Snake River Plain in eastern ID as well as the Independence and Ruby mountains of northeast NV, will augment the dry/windy conditions and should support several hours of elevated fire weather conditions. Isolated to scattered thunderstorms are also anticipated across northern ID, MT, and WY by late afternoon as the low shifts east. While a few dry thunderstorms are possible based on forecast thermal profiles, recent ensemble guidance shows a stronger signal for wetting rainfall compared to Monday, limiting confidence in the dry-lightning threat. ...Central/Northern Plains... A lee trough is expected to become established over the next 24 hours, but will see more substantial deepening through Tuesday afternoon amid increasing synoptic-scale ascent ahead of the approaching upper wave. This will result in not only strengthening westerly downslope flow across eastern WY, but will also bolster pressure gradient winds across central NE into SD. Recent ensemble guidance shows reasonably high confidence in maintaining at least a few hours of elevated fire weather conditions for both regions with 15-20 mph winds and RH reductions into the teens and low 20s. Persistent southerly flow overnight Monday into Tuesday will support some degree of moisture return into the Plains, which is expected to limit the spatial coverage of elevated fire weather conditions. That said, guidance typically struggles to accurately capture boundary-layer mixing/RH reductions in such return flow regimes, and fire weather conditions may be more widespread across NE/SD than currently depicted. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Sep 02 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE CENTRAL TO NORTHERN ROCKIES... ...SUMMARY... A risk of isolated strong to severe storms capable of producing gusty/locally damaging winds will exist from parts of Montana/Wyoming/Colorado into the northern Plains Wednesday/Wednesday night. Marginal hail with stronger storms may also occur across the northern Plains region. ...Synopsis and Discussion... A weak upper trough providing cooling aloft and modest flow will move across the northern Plains on Wednesday, while a cold front moves across the Dakotas, trailing southwestward into the central High Plains by 00Z. High pressure will remain over much of the East, providing stable conditions there, and enhancing southerly winds over the Plains ahead of the front. In general, a plume of 50s to lower 60s F dewpoints will spread north toward the front late in the day. Scattered storms will first form over the higher terrain across eastern MT, WY, and into central CO, with steep lapse rates and modest deep-layer shear favoring marginal hail. Storms will also form along the cold front, from eastern CO into the Dakotas. Backed low-level winds and veering winds with height may support a few supercells, though multicellular clusters will also be likely as winds aloft are on the marginal side for better organized storm structures. Still, favorable time of day and steep low-level lapse rates will likely favor gusty to locally severe gusts as activity spreads across the northern and central Plains through the evening. ..Jewell.. 09/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Sep 02 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE CENTRAL TO NORTHERN ROCKIES... ...SUMMARY... A risk of isolated strong to severe storms capable of producing gusty/locally damaging winds will exist from parts of Montana/Wyoming/Colorado into the northern Plains Wednesday/Wednesday night. Marginal hail with stronger storms may also occur across the northern Plains region. ...Synopsis and Discussion... A weak upper trough providing cooling aloft and modest flow will move across the northern Plains on Wednesday, while a cold front moves across the Dakotas, trailing southwestward into the central High Plains by 00Z. High pressure will remain over much of the East, providing stable conditions there, and enhancing southerly winds over the Plains ahead of the front. In general, a plume of 50s to lower 60s F dewpoints will spread north toward the front late in the day. Scattered storms will first form over the higher terrain across eastern MT, WY, and into central CO, with steep lapse rates and modest deep-layer shear favoring marginal hail. Storms will also form along the cold front, from eastern CO into the Dakotas. Backed low-level winds and veering winds with height may support a few supercells, though multicellular clusters will also be likely as winds aloft are on the marginal side for better organized storm structures. Still, favorable time of day and steep low-level lapse rates will likely favor gusty to locally severe gusts as activity spreads across the northern and central Plains through the evening. ..Jewell.. 09/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Sep 02 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE CENTRAL TO NORTHERN ROCKIES... ...SUMMARY... A risk of isolated strong to severe storms capable of producing gusty/locally damaging winds will exist from parts of Montana/Wyoming/Colorado into the northern Plains Wednesday/Wednesday night. Marginal hail with stronger storms may also occur across the northern Plains region. ...Synopsis and Discussion... A weak upper trough providing cooling aloft and modest flow will move across the northern Plains on Wednesday, while a cold front moves across the Dakotas, trailing southwestward into the central High Plains by 00Z. High pressure will remain over much of the East, providing stable conditions there, and enhancing southerly winds over the Plains ahead of the front. In general, a plume of 50s to lower 60s F dewpoints will spread north toward the front late in the day. Scattered storms will first form over the higher terrain across eastern MT, WY, and into central CO, with steep lapse rates and modest deep-layer shear favoring marginal hail. Storms will also form along the cold front, from eastern CO into the Dakotas. Backed low-level winds and veering winds with height may support a few supercells, though multicellular clusters will also be likely as winds aloft are on the marginal side for better organized storm structures. Still, favorable time of day and steep low-level lapse rates will likely favor gusty to locally severe gusts as activity spreads across the northern and central Plains through the evening. ..Jewell.. 09/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Sep 02 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE CENTRAL TO NORTHERN ROCKIES... ...SUMMARY... A risk of isolated strong to severe storms capable of producing gusty/locally damaging winds will exist from parts of Montana/Wyoming/Colorado into the northern Plains Wednesday/Wednesday night. Marginal hail with stronger storms may also occur across the northern Plains region. ...Synopsis and Discussion... A weak upper trough providing cooling aloft and modest flow will move across the northern Plains on Wednesday, while a cold front moves across the Dakotas, trailing southwestward into the central High Plains by 00Z. High pressure will remain over much of the East, providing stable conditions there, and enhancing southerly winds over the Plains ahead of the front. In general, a plume of 50s to lower 60s F dewpoints will spread north toward the front late in the day. Scattered storms will first form over the higher terrain across eastern MT, WY, and into central CO, with steep lapse rates and modest deep-layer shear favoring marginal hail. Storms will also form along the cold front, from eastern CO into the Dakotas. Backed low-level winds and veering winds with height may support a few supercells, though multicellular clusters will also be likely as winds aloft are on the marginal side for better organized storm structures. Still, favorable time of day and steep low-level lapse rates will likely favor gusty to locally severe gusts as activity spreads across the northern and central Plains through the evening. ..Jewell.. 09/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Sep 02 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE CENTRAL TO NORTHERN ROCKIES... ...SUMMARY... A risk of isolated strong to severe storms capable of producing gusty/locally damaging winds will exist from parts of Montana/Wyoming/Colorado into the northern Plains Wednesday/Wednesday night. Marginal hail with stronger storms may also occur across the northern Plains region. ...Synopsis and Discussion... A weak upper trough providing cooling aloft and modest flow will move across the northern Plains on Wednesday, while a cold front moves across the Dakotas, trailing southwestward into the central High Plains by 00Z. High pressure will remain over much of the East, providing stable conditions there, and enhancing southerly winds over the Plains ahead of the front. In general, a plume of 50s to lower 60s F dewpoints will spread north toward the front late in the day. Scattered storms will first form over the higher terrain across eastern MT, WY, and into central CO, with steep lapse rates and modest deep-layer shear favoring marginal hail. Storms will also form along the cold front, from eastern CO into the Dakotas. Backed low-level winds and veering winds with height may support a few supercells, though multicellular clusters will also be likely as winds aloft are on the marginal side for better organized storm structures. Still, favorable time of day and steep low-level lapse rates will likely favor gusty to locally severe gusts as activity spreads across the northern and central Plains through the evening. ..Jewell.. 09/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Sep 02 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE CENTRAL TO NORTHERN ROCKIES... ...SUMMARY... A risk of isolated strong to severe storms capable of producing gusty/locally damaging winds will exist from parts of Montana/Wyoming/Colorado into the northern Plains Wednesday/Wednesday night. Marginal hail with stronger storms may also occur across the northern Plains region. ...Synopsis and Discussion... A weak upper trough providing cooling aloft and modest flow will move across the northern Plains on Wednesday, while a cold front moves across the Dakotas, trailing southwestward into the central High Plains by 00Z. High pressure will remain over much of the East, providing stable conditions there, and enhancing southerly winds over the Plains ahead of the front. In general, a plume of 50s to lower 60s F dewpoints will spread north toward the front late in the day. Scattered storms will first form over the higher terrain across eastern MT, WY, and into central CO, with steep lapse rates and modest deep-layer shear favoring marginal hail. Storms will also form along the cold front, from eastern CO into the Dakotas. Backed low-level winds and veering winds with height may support a few supercells, though multicellular clusters will also be likely as winds aloft are on the marginal side for better organized storm structures. Still, favorable time of day and steep low-level lapse rates will likely favor gusty to locally severe gusts as activity spreads across the northern and central Plains through the evening. ..Jewell.. 09/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 PM CDT Mon Sep 02 2024 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE CENTRAL TO NORTHERN ROCKIES... ...SUMMARY... A risk of isolated strong to severe storms capable of producing gusty/locally damaging winds will exist from parts of Montana/Wyoming/Colorado into the northern Plains Wednesday/Wednesday night. Marginal hail with stronger storms may also occur across the northern Plains region. ...Synopsis and Discussion... A weak upper trough providing cooling aloft and modest flow will move across the northern Plains on Wednesday, while a cold front moves across the Dakotas, trailing southwestward into the central High Plains by 00Z. High pressure will remain over much of the East, providing stable conditions there, and enhancing southerly winds over the Plains ahead of the front. In general, a plume of 50s to lower 60s F dewpoints will spread north toward the front late in the day. Scattered storms will first form over the higher terrain across eastern MT, WY, and into central CO, with steep lapse rates and modest deep-layer shear favoring marginal hail. Storms will also form along the cold front, from eastern CO into the Dakotas. Backed low-level winds and veering winds with height may support a few supercells, though multicellular clusters will also be likely as winds aloft are on the marginal side for better organized storm structures. Still, favorable time of day and steep low-level lapse rates will likely favor gusty to locally severe gusts as activity spreads across the northern and central Plains through the evening. ..Jewell.. 09/02/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE NORTHERN ROCKIES AND INTO THE EASTERN GREAT BASIN... ...SUMMARY... Scattered strong storms with isolated severe may produce damaging wind gusts and marginal hail from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... On Tuesday, an upper trough will weaken as it moves from the Northwest into the northern Rockies, providing cooling aloft and increased mid and high level flow. To the east, a large upper trough will exit the northeastern states, with height rises over the north-central CONUS. At the surface, a weak cold front will move across the eastern Great Basin, ID, western WY and southwest MT by early afternoon, increasing lift/convergence. Elsewhere, a moist air mass will remain from TX eastward across the Gulf Coast, with scattered non-severe storms likely. ...Eastern Great Basin into the Northern Rockies... As heating accelerates and cooler temperatures overspread the region, steep lapse rates will yield a large area of thunderstorms, developing relatively early in the afternoon, from much of UT into southwest MT. The strongest instability with 500 to 1000 J/kg MUCAPE will be roughly from far northern UT into MT, where temperatures aloft will be coolest. Deep-layer effective shear will increase to around 40 kt, especially across ID, MT, and northwest WY, which will aid cellular storm mode and hail potential to around 1.00" in diameter. Otherwise, scattered storms across the entire area will produce outflows, with progressive clusters of storms producing strong to locally severe gusts. A few storms may make it as far east as western SD by late evening, with generally decreasing intensity after sunset. ..Jewell.. 09/02/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1227 PM CDT Mon Sep 02 2024 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER MUCH OF THE NORTHERN ROCKIES AND INTO THE EASTERN GREAT BASIN... ...SUMMARY... Scattered strong storms with isolated severe may produce damaging wind gusts and marginal hail from the northern Intermountain region eastward into the northern High Plains, and southward into Utah. ...Synopsis... On Tuesday, an upper trough will weaken as it moves from the Northwest into the northern Rockies, providing cooling aloft and increased mid and high level flow. To the east, a large upper trough will exit the northeastern states, with height rises over the north-central CONUS. At the surface, a weak cold front will move across the eastern Great Basin, ID, western WY and southwest MT by early afternoon, increasing lift/convergence. Elsewhere, a moist air mass will remain from TX eastward across the Gulf Coast, with scattered non-severe storms likely. ...Eastern Great Basin into the Northern Rockies... As heating accelerates and cooler temperatures overspread the region, steep lapse rates will yield a large area of thunderstorms, developing relatively early in the afternoon, from much of UT into southwest MT. The strongest instability with 500 to 1000 J/kg MUCAPE will be roughly from far northern UT into MT, where temperatures aloft will be coolest. Deep-layer effective shear will increase to around 40 kt, especially across ID, MT, and northwest WY, which will aid cellular storm mode and hail potential to around 1.00" in diameter. Otherwise, scattered storms across the entire area will produce outflows, with progressive clusters of storms producing strong to locally severe gusts. A few storms may make it as far east as western SD by late evening, with generally decreasing intensity after sunset. ..Jewell.. 09/02/2024 Read more