SPC MD 2045

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 Sep 3, 2024 2000 UTC Day 1 Convective Outlook

10 months 2 weeks ago
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 MD 2044

10 months 2 weeks ago
MD 2044 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHWEST MT AND NORTHWEST WY
Mesoscale Discussion 2044 NWS Storm Prediction Center Norman OK 0107 PM CDT Tue Sep 03 2024 Areas affected...southwest MT and northwest WY Concerning...Severe potential...Watch unlikely Valid 031807Z - 032000Z Probability of Watch Issuance...20 percent SUMMARY...A few weak supercells may develop by late afternoon across parts of the northern Rockies. Isolated severe hail and strong to localized severe gusts will be possible. DISCUSSION...Convection has gradually increased into midday, but should increase more prominently by 19-20Z as MLCIN further wanes and large-scale ascent persists downstream of a smoke-filled mid-level low near the Bitterroot Range. To its southeast, the Pocatello VWP has consistently sampled the belt of stronger mid-level southwesterlies from 40-45 kts, with values likely in the 30s farther north across southwest MT. With a confined mid-level cold core gradually shifting east, the greater potential for 0.75-1.5 inch hail should be focused initially across southwest MT. With moderate surface temperature-dew point spreads near/west of the Absaroka Range, wind gusts should largely be sub-severe, but may locally reach 50-65 mph. Somewhat greater wind potential may occur farther east from the Lewiston-Billings-Cody corridor as convection spreads into a more deeply mixed environment later. ..Grams/Smith.. 09/03/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...RIW...TFX...PIH...MSO... LAT...LON 46690982 46020913 45450886 44410902 43460977 43471074 43581127 43731127 43921111 44351102 44741107 45191132 45001245 44921341 45121406 45851377 46281393 46581408 46831407 47111339 47221233 47051100 46690982 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more

SPC Sep 3, 2024 1930 UTC Day 3 Severe Thunderstorm Outlook

10 months 2 weeks ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 PM CDT Tue Sep 03 2024 Valid 051200Z - 061200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The threat for organized severe thunderstorms currently appears low on Thursday. ...Synopsis... A mid-level trough will amplify across the Upper Midwest and Canadian Prairies on Thursday. Ahead of this trough, an elongated frontal zone will extend from northern Ontario, across the Great Lakes, across the central Plains, and into the southern High Plains. Moisture will remain somewhat meager along this frontal zone with storm coverage likely focused near the higher terrain in New Mexico and the better forcing in the western Great Lakes. ...Western Great Lakes... Strong height falls/cooling temperatures aloft should be sufficient to allow for some scattered storm development along the cold front in the western Great Lakes vicinity on Thursday afternoon/evening. However, despite the strong forcing, instability will be somewhat limited and thus, severe storms are unlikely. ...Northeast New Mexico... A southeastward moving mid-level shortwave trough will move toward northeast New Mexico and provide ample forcing for storms Thursday afternoon/evening. Instability will remain weak, but may be sufficient for a few stronger storms. If greater instability can develop, enough deep-layer shear will be present for some storm organization (~25 knots), but at this time, instability remains too weak for a Marginal risk. ..Bentley.. 09/03/2024 Read more