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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...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 0259 PM CDT Tue Sep 03 2024 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes are needed to the D2 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 09/03/2024 .PREV DISCUSSION... /ISSUED 0127 AM CDT Tue Sep 03 2024/ ...Synopsis... Fire weather concerns are expected to be limited for Wednesday across the country. The upper-level low currently over parts of the Pacific Northwest is forecast to de-amplify and drift east into the Plains. As this occurs, weak ascent will support widespread cloud cover as well as isolated to scattered showers and thunderstorms across the central Rockies to central Plains. The surface pressure trough currently in place along the High Plains will shift east/southeast through the day, and while breezy conditions are likely just ahead of the boundary, increasing moisture return into the Plains will modulate diurnal RH reductions. Across the West, building surface high pressure should limit wind speeds. Consequently, the potential for elevated fire weather concerns appears limited with no highlights required. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2045 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWESTERN WY INTO NORTH-CENTRAL UT AND EXTREME SOUTHEASTERN ID
Mesoscale Discussion 2045 NWS Storm Prediction Center Norman OK 0131 PM CDT Tue Sep 03 2024 Areas affected...southwestern WY into north-central UT and extreme southeastern ID Concerning...Severe potential...Watch unlikely Valid 031831Z - 032030Z Probability of Watch Issuance...20 percent SUMMARY...Scattered thunderstorm development is underway across southwestern WY into extreme southeastern ID and north-central UT. This is expected to continue through the afternoon with some severe gusts possible with the strongest storms. The overall threat is expected to remain low, and a watch is unlikely at this time. DISCUSSION...Numerous towering updrafts have developed in the last hour along the higher terrain across central UT and eastern NV per visible satellite imagery. These maturing storms are driven by diurnal heating and a weakening mid-level trough propagating eastward through the region. Deep, well-mixed boundary layers abound in this environment, as characterized by short-term RAP and NAM forecast profiles. Steadily increasing westerly flow is anticipated as the mid-level trough approaches, yielding relatively unidirectional 0-6-km shear around 25+ kts. This should support some updraft organization and rotation, possibly including transient, high-based supercell structures. Localized severe wind gusts are possible with microbursts forming from stronger cores that encourage descent through the deep, well-mixed boundary layer. This severe risk should continue through peak heating, but the overall threat is expected to remain rather marginal, and a watch appears unlikely at this time. ..Flournoy/Squitieri/Smith.. 09/03/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...RIW...GJT...SLC...PIH... LAT...LON 41221266 42161163 42981038 42980935 41890877 40480916 39461034 38791144 38741273 39551381 40691337 41221266 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Tue Sep 03 2024 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN ROCKIES/GREAT BASIN AND ADJACENT HIGH PLAINS... ...SUMMARY... Scattered thunderstorms developing across the northern Rockies and adjacent portions of the Great Basin this afternoon will pose an isolated severe risk, before spreading eastward toward the northern High Plains this evening. ...20Z Update... The previous forecast remains on track, and no changes were made with this update. Widely scattered thunderstorms are evolving across the northern Rockies and adjacent Great Basin this afternoon. These storms are generally focused in a band of midlevel ascent preceding a compact midlevel low tracking eastward across central ID. This activity will continue spreading east-northeastward through the afternoon, with initial semi-discrete clusters/transient supercells posing a risk of sporadic, marginally severe hail and locally severe gusts. See MCDs 2044/2045 for details on the near-term severe risk. Later this afternoon, a more-focused corridor of severe-wind potential is possible from portions of northwest WY into southwest/south-central MT, especially with any upscale-grown clusters amid steep deep-layer lapse rates. A 15-percent wind-driven Slight Risk was considered here, though confidence in the development of an organized/consolidated cold pool remains too low for an upgrade. ..Weinman.. 09/03/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Tue Sep 03 2024/ ...Northern Great Basin/Rockies into the Adjacent High Plains... Visible-satellite imagery this morning shows a smoke-encased mid to upper-level low/vorticity maximum over central ID. This upper feature will move to near southwest MT/eastern ID late tonight. The satellite data late this morning shows agitated cumulus developing immediately ahead of the vorticity max near the ID/MT border, and as large-scale ascent spreads east, additional thunderstorms (widely scattered to scattered coverage) should develop over the higher terrain through early afternoon in tandem with daytime heating. Forecast soundings across southwest MT into northwest WY show 500-1000 J/kg MLCAPE with some elongation of the hodograph. A few of the stronger storms will probably acquire transient supercell characteristics and have an associated hail/wind threat. Some clustering may eventually evolve by early evening as storms move into south-central MT and adjacent parts of northern WY. Somewhat more limited low-level moisture should be present this afternoon farther south into WY and northern UT. Even so, diurnal heating will aid in a deeply mixed boundary layer by this afternoon, and steep mid-level lapse rates are also expected to remain over this region. The net result will be high-based thunderstorms capable of producing isolated severe gusts initially developing across northern UT into far eastern ID, and subsequently moving east-northeastward over WY through the evening. Read more