Severe Storms

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 1231 AM CDT Fri Jul 26 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND EVENING ACROSS PARTS OF SOUTHEASTERN ARIZONA AND ADJACENT SOUTHWESTERN NEW MEXICO...PARTS OF NORTHEASTERN NEVADA INTO WESTERN UTAH...PARTS OF WESTERN NEBRASKA AND ADJACENT SOUTHEASTERN WYOMING INTO CENTRAL SOUTH DAKOTA...AND PARTS OF EASTERN NORTH DAKOTA INTO NORTHWESTERN MINNESOTA... CORRECTED FOR GEN THUNDER LINE/NDFD GRAPHIC ...SUMMARY... The risk for severe thunderstorms appears seasonably low across much of the U.S. today through tonight. ...Discussion... A significant inland migrating mid-level trough (and embedded low) is now progressing east-northeast of the Canadian and northern U.S. Rockies, and forecast to continue eastward across the Canadian Prairies today through tonight. While stronger mid-level height falls likely remain focused well to the north of the international border area, models indicate that mid-level heights will continue to fall across much of the West into the northern Great Plains, as weak trailing troughing develops inland of the Pacific coast and downstream ridging becomes increasingly suppressed. In lower levels, to the south of a deepening surface cyclone associated with the primary short wave perturbation, a modest cold front may advance east of the northern Rockies, before stalling and weakening across the northern Great Plains into northern portions of the Great Basin. As this regime evolves, destabilization associated with strong daytime heating and remnant monsoonal moisture appears likely to support considerable thunderstorm development this afternoon and evening across the higher terrain of eastern Arizona through the southern Rockies, and near lee surface troughing across the north central high plains. Additional, more widely scattered, thunderstorm activity may focus near/just ahead of the surface front across the northern Great Basin through portions of the northern Rockies and northern Great Plains. Some of the stronger, more persistent convection will probably overspread, or develop above, more strongly heated and deeply mixed (with large developing surface temperature-dew point spreads) lower elevations, accompanied by a risk for strong to locally severe wind gusts. ...Eastern North Dakota/Northwestern Minnesota... Beneath a plume of very warm and capping elevated mixed-layer air, which will continue to advect northeastward across the northern Great Plains through the day, models indicate that seasonably moist boundary-layer air may support a narrow corridor of large potential instability across the Red River Valley vicinity into the stalling weakening frontal zone across northwestern Minnesota/southeastern Manitoba/adjacent northwest Ontario by early evening. Downstream of the base of the short wave perturbation crossing the Canadian Prairies, forcing for ascent may support isolated to widely scattered thunderstorm development. In the presence of at least 30-40 kt deep-layer shear, and modest clockwise-curved low-level hodographs, one or two supercells appear possible to the south of the international border, perhaps as far southwest as areas near/west of Grand Forks and Fargo. ..Kerr.. 07/26/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1154 PM CDT Thu Jul 25 2024 Valid 261200Z - 271200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND EVENING ACROSS PARTS OF SOUTHEASTERN ARIZONA AND ADJACENT SOUTHWESTERN NEW MEXICO...PARTS OF NORTHEASTERN NEVADA INTO WESTERN UTAH...PARTS OF WESTERN NEBRASKA AND ADJACENT SOUTHEASTERN WYOMING INTO CENTRAL SOUTH DAKOTA...AND PARTS OF EASTERN NORTH DAKOTA INTO NORTHWESTERN MINNESOTA... ...SUMMARY... The risk for severe thunderstorms appears seasonably low across much of the U.S. today through tonight. ...Discussion... A significant inland migrating mid-level trough (and embedded low) is now progressing east-northeast of the Canadian and northern U.S. Rockies, and forecast to continue eastward across the Canadian Prairies today through tonight. While stronger mid-level height falls likely remain focused well to the north of the international border area, models indicate that mid-level heights will continue to fall across much of the West into the northern Great Plains, as weak trailing troughing develops inland of the Pacific coast and downstream ridging becomes increasingly suppressed. In lower levels, to the south of a deepening surface cyclone associated with the primary short wave perturbation, a modest cold front may advance east of the northern Rockies, before stalling and weakening across the northern Great Plains into northern portions of the Great Basin. As this regime evolves, destabilization associated with strong daytime heating and remnant monsoonal moisture appears likely to support considerable thunderstorm development this afternoon and evening across the higher terrain of eastern Arizona through the southern Rockies, and near lee surface troughing across the north central high plains. Additional, more widely scattered, thunderstorm activity may focus near/just ahead of the surface front across the northern Great Basin through portions of the northern Rockies and northern Great Plains. Some of the stronger, more persistent convection will probably overspread, or develop above, more strongly heated and deeply mixed (with large developing surface temperature-dew point spreads) lower elevations, accompanied by a risk for strong to locally severe wind gusts. ...Eastern North Dakota/Northwestern Minnesota... Beneath a plume of very warm and capping elevated mixed-layer air, which will continue to advect northeastward across the northern Great Plains through the day, models indicate that seasonably moist boundary-layer air may support a narrow corridor of large potential instability across the Red River Valley vicinity into the stalling weakening frontal zone across northwestern Minnesota/southeastern Manitoba/adjacent northwest Ontario by early evening. Downstream of the base of the short wave perturbation crossing the Canadian Prairies, forcing for ascent may support isolated to widely scattered thunderstorm development. In the presence of at least 30-40 kt deep-layer shear, and modest clockwise-curved low-level hodographs, one or two supercells appear possible to the south of the international border, perhaps as far southwest as areas near/west of Grand Forks and Fargo. ..Kerr/Halbert/Weinman.. 07/26/2024 Read more

WW 0560 Status Updates
STATUS REPORT ON WW 560 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 70 NNE BIL TO 70 NNW GGW. ..HALBERT..07/26/24 ATTN...WFO...TFX...GGW... STATUS REPORT FOR WS 560 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC019-033-105-260340- MT . MONTANA COUNTIES INCLUDED ARE DANIELS GARFIELD VALLEY THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

MD 1710 CONCERNING SEVERE THUNDERSTORM WATCH 560... FOR NORTH CENTRAL AND EASTERN MONTANA
Mesoscale Discussion 1710 NWS Storm Prediction Center Norman OK 0749 PM CDT Thu Jul 25 2024 Areas affected...North Central and Eastern Montana Concerning...Severe Thunderstorm Watch 560... Valid 260049Z - 260145Z The severe weather threat for Severe Thunderstorm Watch 560 continues. SUMMARY...The severe threat for WW 560 continues, as thunderstorms in northern Montana have organized into a bowing MCS with outflow winds capable of severe gusts. DISCUSSION...Dry, well mixed boundary layer profiles have supported the organization of thunderstorm outflow into linear bowing segments capable of 60-70 MPH wind gusts across northern Montana. The most intense corridor of thunderstorm winds is currently approaching Glasgow, where the apex of the outflow bowing segment shows 55-60 kt winds at 1200-1500 feet above ground. Given the well mixed nature of the boundary layer, there is little preventing the transfer of this momentum to the surface and could result in reports of wind damage. Depending on the longevity of the linear segments, local watch extension eastward could be needed. ..Halbert/Weinman.. 07/26/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW... LAT...LON 48220806 48500808 48710785 48810739 48850706 48890662 48930629 48850596 48740580 48370575 48160573 47550583 47330584 46850603 46770623 46680677 46700726 46700781 46760800 47040814 47320821 47830827 48130815 48220806 Read more

WW 0560 Status Updates
STATUS REPORT ON WW 560 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 N BIL TO 80 NW GGW. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1710 ..HALBERT..07/26/24 ATTN...WFO...TFX...GGW... STATUS REPORT FOR WS 560 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC019-033-069-071-105-260240- MT . MONTANA COUNTIES INCLUDED ARE DANIELS GARFIELD PETROLEUM PHILLIPS VALLEY THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 560 SEVERE TSTM MT 252145Z - 260500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 560 NWS Storm Prediction Center Norman OK 345 PM MDT Thu Jul 25 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of North Central Montana * Effective this Thursday afternoon and evening from 345 PM until 1100 PM MDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms will continue to intensify over north-central Montana and track quickly eastward through the afternoon and evening. Damaging wind gusts are the main threat with these storms. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 50 miles east southeast of Lewistown MT to 70 miles northwest of Glasgow MT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Hart Read more

MD 1709 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR LOWER DESERTS OF ARIZONA
Mesoscale Discussion 1709 NWS Storm Prediction Center Norman OK 0625 PM CDT Thu Jul 25 2024 Areas affected...Lower Deserts of Arizona Concerning...Severe potential...Watch unlikely Valid 252325Z - 260130Z Probability of Watch Issuance...20 percent SUMMARY...Gusty winds are possible with convection this evening. DISCUSSION...Scattered thunderstorms are gradually expanding in areal coverage over the higher terrain early this evening. This activity has developed within a weak-flow regime that favors southward propagation toward lower-desert regions. Latest diagnostic data suggests a modest corridor of MLCAPE exists from Maricopa county to near the international border. Convection that spreads into this airmass may generate gusty winds as PW values are in excess of 1.5 inches, and sub-cloud (3km AGL) RH is fairly low. At this time current thinking is the severe gust potential may be a bit too isolated to warrant a severe thunderstorm watch. Will continue to monitor for convective organization. ..Darrow/Hart.. 07/25/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...PSR... LAT...LON 31871308 33561268 33401101 32490979 31261023 31871308 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0741 PM CDT Thu Jul 25 2024 Valid 260100Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING ACROSS PARTS OF CENTRAL INTO NORTHEASTERN MONTANA... ...SUMMARY... Thunderstorm activity developing across parts of the Intermountain West and Rockies vicinity may pose a risk for strong to locally severe wind gusts into this evening. ...01Z Update... ...Central/Northeast Montana... Modest pre-frontal boundary-layer moisture has only become supportive of weak CAPE, but forcing for ascent downstream of mid-level troughing crossing the Canadian/northern U.S. Rockies has been sufficient to contribute to a broken line of thunderstorms approaching the Glasgow/Jordan vicinities. Although this activity does not appear particularly vigorous, evaporative cooling of precipitation within the hot and deeply mixed sub-cloud layer, coupled with downward mixing of modest westerly ambient mid-level flow, may still contribute to a few strong to severe wind gusts until convection dissipates later this evening. ...Arizona... A number of storms have developed near the Mogollon Rim vicinity. While there has been little indication of appreciable upscale growth, a number of outflows generated by this activity are surging toward the more strongly heated and deeply mixed lower elevations around the Greater Phoenix area, aided by light northerly to east-northeasterly mid/upper flow. Even with 50-60 degree surface temperature-dew point spreads, there appears sufficient instability to support renewed thunderstorm development posing a risk for additional locally strong downbursts through mid to late evening. ..Kerr.. 07/26/2024 Read more

WW 0560 Status Updates
STATUS REPORT ON WW 560 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNE 3HT TO 45 NNE HVR. ..HALBERT..07/25/24 ATTN...WFO...TFX...GGW... STATUS REPORT FOR WS 560 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC005-019-027-033-069-071-105-260040- MT . MONTANA COUNTIES INCLUDED ARE BLAINE DANIELS FERGUS GARFIELD PETROLEUM PHILLIPS VALLEY THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

MD 1709 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR LOWER DESERTS OF ARIZONA
Mesoscale Discussion 1709 NWS Storm Prediction Center Norman OK 0625 PM CDT Thu Jul 25 2024 Areas affected...Lower Deserts of Arizona Concerning...Severe potential...Watch unlikely Valid 252325Z - 260130Z Probability of Watch Issuance...20 percent SUMMARY...Gusty winds are possible with convection this evening. DISCUSSION...Scattered thunderstorms are gradually expanding in areal coverage over the higher terrain early this evening. This activity has developed within a weak-flow regime that favors southward propagation toward lower-desert regions. Latest diagnostic data suggests a modest corridor of MLCAPE exists from Maricopa county to near the international border. Convection that spreads into this airmass may generate gusty winds as PW values are in excess of 1.5 inches, and sub-cloud (3km AGL) RH is fairly low. At this time current thinking is the severe gust potential may be a bit too isolated to warrant a severe thunderstorm watch. Will continue to monitor for convective organization. ..Darrow/Hart.. 07/25/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...PSR... LAT...LON 31871308 33561268 33401101 32490979 31261023 31871308 Read more

WW 0560 Status Updates
STATUS REPORT ON WW 560 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNE 3HT TO 45 NNE HVR. ..HALBERT..07/25/24 ATTN...WFO...TFX...GGW... STATUS REPORT FOR WS 560 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC005-019-027-033-069-071-105-260040- MT . MONTANA COUNTIES INCLUDED ARE BLAINE DANIELS FERGUS GARFIELD PETROLEUM PHILLIPS VALLEY THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 560 SEVERE TSTM MT 252145Z - 260500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 560 NWS Storm Prediction Center Norman OK 345 PM MDT Thu Jul 25 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of North Central Montana * Effective this Thursday afternoon and evening from 345 PM until 1100 PM MDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms will continue to intensify over north-central Montana and track quickly eastward through the afternoon and evening. Damaging wind gusts are the main threat with these storms. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 50 miles east southeast of Lewistown MT to 70 miles northwest of Glasgow MT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Hart Read more