SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CDT Tue Aug 20 2024 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN MONTANA AND WESTERN NORTH DAKOTA... ...SUMMARY... Scattered thunderstorms, some with severe hail and damaging gusts are expected to develop on Wednesday over parts of far eastern Montana and western North Dakota. ...Central and Northern Plains... An upper-level ridge is forecast to move eastward across the northern Plains on Wednesday, as a subtle shortwave trough moves into the northern High Plains in southwesterly mid-level flow. At the surface, a lee low in southeastern Montana is forecast to deepen ahead of an approaching front. Warming surface temperatures ahead of the front combined with surface dewpoints in the lower to mid 60s F, will likely result in a southeast-to-northwest corridor of moderate instability by afternoon. Thunderstorms appear likely to develop in the mid to late afternoon near the front and in the higher terrain of central and southern Montana. The models are now in better agreement concerning the magnitude of instability, with MLCAPE expected to reach the 3500 to 5000 J/kg range along the instability axis. Thunderstorms that move toward the instability axis will have a chance to be severe. Most NAM forecast soundings near the instability axis by 00Z/Thursday have 0-6 km shear in the 40 to 50 knot range with 700 to 500 mb lapse rates of 8 to 9 C/km. This would be favorable for supercells with large hail. Storm bases should be high due to large temperature-dewpoint spreads, which will contribute to the wind-damage potential. Far eastern Montana and western North Dakotas should be impacted during the evening, as low-level flow gradually ramps up. Further to the south into the central High Plains, an axis of moderate instability is forecast to develop by afternoon from west-central Nebraska south-southwestward into northeastern Colorado. By mid afternoon, thunderstorms are expected to form in the higher terrain of southern Wyoming and central Colorado, with this convection moving eastward into the lower elevations. Thunderstorms that move into the most and unstable airmass over the central High Plains will have a chance to become severe. 0-6 km shear around 30 knots combined with steep mid-level lapse rates will support an isolated threat for large hail and severe gusts, with the threat concentrated in the late afternoon and early evening. ..Broyles.. 08/20/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Tue Aug 20 2024 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MONTANA... ...SUMMARY... Widely scattered to scattered storms are possible in parts of central/eastern Montana with more isolated coverage into parts of the central High Plains. Severe winds and large hail are the primary threats. ...MT into the Central High Plains... Upper ridge is forecast to hold across the High Plains through the day1 period, though some weak mid-level height falls are expected across the northern Rockies in response to a very weak disturbance. With broad southwesterly flow entrenched across the northern intermountain region into central MT, a surface lee trough will arc from central MT-western Black Hills-eastern CO. This will ensure southeasterly boundary-layer winds are maintained across the northern High Plains into central MT. Strong surface heating will allow temperatures to warm into the 90s across eastern MT and convective temperatures should be breached at lower elevations by 20z. Latest thinking is scattered convection will develop over the higher terrain of southern MT then spread northeast toward the High Plains. NAM forecast sounding for LWT at 20z exhibits 2300 J/kg MLCAPE with 0-6km bulk shear around 50kt. This profile suggests supercells are likely, especially early in the convective cycle. Relatively high cloud bases favor strong gusts and this should be the primary risk, though large hail is certainly possible with supercells. Scattered convection should spread toward eastern MT where gradual weakening is expected during the late evening. Farther south, a very weak disturbance will rotate around the southern Rockies anticyclone into eastern CO by late afternoon. Scattered convection should easily develop over the higher terrain of southern CO then spread east along/north of a front that will be draped from northwest OK into southeast CO. Favorable veering wind profiles with height, along with 0-6km shear on the order of 30kt, suggests slow-moving supercells could spread east-southeast during the late afternoon/evening. Isolated hail/wind are the primary threats. ..Darrow/Halbert.. 08/20/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Tue Aug 20 2024 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MONTANA... ...SUMMARY... Widely scattered to scattered storms are possible in parts of central/eastern Montana with more isolated coverage into parts of the central High Plains. Severe winds and large hail are the primary threats. ...MT into the Central High Plains... Upper ridge is forecast to hold across the High Plains through the day1 period, though some weak mid-level height falls are expected across the northern Rockies in response to a very weak disturbance. With broad southwesterly flow entrenched across the northern intermountain region into central MT, a surface lee trough will arc from central MT-western Black Hills-eastern CO. This will ensure southeasterly boundary-layer winds are maintained across the northern High Plains into central MT. Strong surface heating will allow temperatures to warm into the 90s across eastern MT and convective temperatures should be breached at lower elevations by 20z. Latest thinking is scattered convection will develop over the higher terrain of southern MT then spread northeast toward the High Plains. NAM forecast sounding for LWT at 20z exhibits 2300 J/kg MLCAPE with 0-6km bulk shear around 50kt. This profile suggests supercells are likely, especially early in the convective cycle. Relatively high cloud bases favor strong gusts and this should be the primary risk, though large hail is certainly possible with supercells. Scattered convection should spread toward eastern MT where gradual weakening is expected during the late evening. Farther south, a very weak disturbance will rotate around the southern Rockies anticyclone into eastern CO by late afternoon. Scattered convection should easily develop over the higher terrain of southern CO then spread east along/north of a front that will be draped from northwest OK into southeast CO. Favorable veering wind profiles with height, along with 0-6km shear on the order of 30kt, suggests slow-moving supercells could spread east-southeast during the late afternoon/evening. Isolated hail/wind are the primary threats. ..Darrow/Halbert.. 08/20/2024 Read more

MD 1962 CONCERNING SEVERE THUNDERSTORM WATCH 640... FOR NORTH-CENTRAL MONTANA
Mesoscale Discussion 1962 NWS Storm Prediction Center Norman OK 0931 PM CDT Mon Aug 19 2024 Areas affected...north-central Montana Concerning...Severe Thunderstorm Watch 640... Valid 200231Z - 200400Z The severe weather threat for Severe Thunderstorm Watch 640 continues. SUMMARY...Risk for locally damaging wind gusts continues across parts of north-central Montana, in/near WW 640. DISCUSSION...Latest radar loop shows that as storms have descended from higher elevations into a more moist/unstable airmass, intensification/organization of the storms into a loose banded structure has occurred. The convection is moving northeastward at around 40 kt, and has produced wind gusts in the 50 to 60 MPH range over the past hour, along with small hail. Expect risk for damaging wind gusts to continue locally over the next hour or so, before storms weaken -- and begin moving across the international border. This should correspond well to the currently scheduled 20/04Z expiration time set for WW 640. ..Goss.. 08/20/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW...TFX... LAT...LON 47961130 48241110 48841063 48920826 47100859 46680943 47091000 47631058 47961130 Read more

WW 0639 Status Updates
STATUS REPORT ON WW 639 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NE DEN TO 35 WNW AKO TO 30 NNE AKO TO 40 ENE SNY AND 30 WSW PUB TO 35 SSE ITR TO 45 NNW GLD TO 30 W AKO. ..HALBERT..08/20/24 ATTN...WFO...GLD...PUB...BOU...CYS... STATUS REPORT FOR WS 639 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC025-061-089-101-121-200340- CO . COLORADO COUNTIES INCLUDED ARE CROWLEY KIOWA OTERO PUEBLO WASHINGTON 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 639 SEVERE TSTM CO NE WY 191945Z - 200300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 639 NWS Storm Prediction Center Norman OK 145 PM MDT Mon Aug 19 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Nebraska Panhandle Southeast Wyoming * Effective this Monday afternoon and evening from 145 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms are expected to build eastward off the foothills of this afternoon, spreading across the watch area. The strongest storms will pose a risk of large hail and locally damaging wind gusts. The severe thunderstorm watch area is approximately along and 35 statute miles east and west of a line from 25 miles southeast of Pueblo CO to 20 miles northwest of Chadron NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24025. ...Hart Read more

WW 0640 Status Updates
STATUS REPORT ON WW 640 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 SE GTF TO 35 SW GTF TO 10 ESE 3DU TO 50 NW SMN. ..GOSS..08/20/24 ATTN...WFO...MSO...TFX... STATUS REPORT FOR WS 640 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC013-015-027-029-035-039-041-045-047-049-051-063-073-077-081- 099-101-200340- MT . MONTANA COUNTIES INCLUDED ARE CASCADE CHOUTEAU FERGUS FLATHEAD GLACIER GRANITE HILL JUDITH BASIN LAKE LEWIS AND CLARK LIBERTY MISSOULA PONDERA POWELL RAVALLI TETON TOOLE 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 640 SEVERE TSTM ID MT 192050Z - 200400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 640 NWS Storm Prediction Center Norman OK 250 PM MDT Mon Aug 19 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Idaho Western and Central Montana * Effective this Monday afternoon and evening from 250 PM until 1000 PM MDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms are forming over the mountains of northern Idaho and western Montana. These storms will intensify and organize through the afternoon and spread northeastward across the watch area. Damaging wind gusts will be possible in the strongest storms. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 35 miles east southeast of Salmon ID to 35 miles northeast of Cut Bank 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. && OTHER WATCH INFORMATION...CONTINUE...WW 639... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 23025. ...Hart Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0733 PM CDT Mon Aug 19 2024 Valid 200100Z - 201200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL/NORTHERN HIGH PLAINS INTO WESTERN MONTANA... ...SUMMARY... Scattered severe thunderstorms are possible across portions of the northern and central High Plains, and over western Montana. Large hail and severe gusts are the primary hazards. ...01z Update... Notable mid-level short-wave trough is topping the northern High Plains ridge over eastern MT early this evening. A secondary, less amplified disturbance is ejecting across the Bitter Roots of ID into extreme western MT. Each of these features appears partly responsible for scattered robust convection immediately downstream. Latest diagnostic data suggests an axis of 1000-2000 J/kg MLCAPE extends across the central High Plains from eastern CO-NE Panhandle-eastern MT. This axis of buoyancy will be the primary corridor for strong/severe thunderstorms this evening. Both GGW and UNR exhibited modest instability, with ample 0-6km shear, for slow-moving supercells; though, both had CINH and capping at the top of the boundary layer around 1km AGL. Primary concentration of longer-lived clusters will likely shift into the western Dakotas as this is where the LLJ should strengthen after sunset. Hail/wind remain the primary risks. ..Darrow.. 08/20/2024 Read more

No Mesoscale Discussions are in effect as of Mon Aug 19 23:03:10 UTC 2024.

WW 0639 Status Updates
STATUS REPORT ON WW 639 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..HALBERT..08/19/24 ATTN...WFO...GLD...PUB...BOU...CYS... STATUS REPORT FOR WS 639 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC017-025-039-041-061-063-073-075-087-089-101-121-123-125- 200040- CO . COLORADO COUNTIES INCLUDED ARE CHEYENNE CROWLEY ELBERT EL PASO KIOWA KIT CARSON LINCOLN LOGAN MORGAN OTERO PUEBLO WASHINGTON WELD YUMA NEC007-013-033-045-105-123-157-165-200040- NE . NEBRASKA COUNTIES INCLUDED ARE BANNER BOX BUTTE CHEYENNE DAWES KIMBALL MORRILL SCOTTS BLUFF SIOUX WYC015-021-200040- WY Read more

WW 639 SEVERE TSTM CO NE WY 191945Z - 200300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 639 NWS Storm Prediction Center Norman OK 145 PM MDT Mon Aug 19 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Nebraska Panhandle Southeast Wyoming * Effective this Monday afternoon and evening from 145 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms are expected to build eastward off the foothills of this afternoon, spreading across the watch area. The strongest storms will pose a risk of large hail and locally damaging wind gusts. The severe thunderstorm watch area is approximately along and 35 statute miles east and west of a line from 25 miles southeast of Pueblo CO to 20 miles northwest of Chadron NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24025. ...Hart Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0457 PM CDT Mon Aug 19 2024 Valid 211200Z - 271200Z Omega blocking over the central CONUS is forecast to remain through the majority of the extended forecast period. On the western flank of the block, mid-level troughing will persist over parts of the West Coast into next weekend. Enhanced flow aloft, with several embedded shortwave troughs will support periodic dry and breezy conditions over parts of the Northwest and Great Basin. Toward the end of the week, a strong upper low will move south along the coast supporting an increase in thunderstorm potential, along with continued dry and breezy conditions over the Great Basin. Elevated to potentially critical fire-weather conditions are possible. ...Northwest and Great Basin... Moderate southwesterly flow aloft is forecast to remain in place over the western US through much of the week. With stronger flow aloft overspreading a warm and dry air mass across parts of the southern Northwest and Great Basin, dry and windy conditions are possible through midweek. Elevated to critical fire-weather conditions are possible over parts of NV, UT and into southern OR/ID through D5/Friday. Confidence in stronger sustained winds overlapping critical RH and dry fuels is somewhat limited currently, though the approach of the upper low/trough is expected to support potentially higher gusts over much of the Southwest D4/Thursday and into the weekend. Increasing monsoon moisture is also expected over parts of the Western US beginning D4/Thursday. Medium-range guidance shows a plume of 0.6 to 0.8 inch PWATs moving into the Pacific Northwest ahead of the upper low. Some dry lightning will be possible with isolated to widely scattered storms through D6/Saturday. Confidence is highest that dry thunder probabilities could be needed over parts of northern and central OR through the end of the work week. However, the exact storm coverage and overlap with the best fuels remains uncertain. ..Lyons.. 08/19/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0457 PM CDT Mon Aug 19 2024 Valid 211200Z - 271200Z Omega blocking over the central CONUS is forecast to remain through the majority of the extended forecast period. On the western flank of the block, mid-level troughing will persist over parts of the West Coast into next weekend. Enhanced flow aloft, with several embedded shortwave troughs will support periodic dry and breezy conditions over parts of the Northwest and Great Basin. Toward the end of the week, a strong upper low will move south along the coast supporting an increase in thunderstorm potential, along with continued dry and breezy conditions over the Great Basin. Elevated to potentially critical fire-weather conditions are possible. ...Northwest and Great Basin... Moderate southwesterly flow aloft is forecast to remain in place over the western US through much of the week. With stronger flow aloft overspreading a warm and dry air mass across parts of the southern Northwest and Great Basin, dry and windy conditions are possible through midweek. Elevated to critical fire-weather conditions are possible over parts of NV, UT and into southern OR/ID through D5/Friday. Confidence in stronger sustained winds overlapping critical RH and dry fuels is somewhat limited currently, though the approach of the upper low/trough is expected to support potentially higher gusts over much of the Southwest D4/Thursday and into the weekend. Increasing monsoon moisture is also expected over parts of the Western US beginning D4/Thursday. Medium-range guidance shows a plume of 0.6 to 0.8 inch PWATs moving into the Pacific Northwest ahead of the upper low. Some dry lightning will be possible with isolated to widely scattered storms through D6/Saturday. Confidence is highest that dry thunder probabilities could be needed over parts of northern and central OR through the end of the work week. However, the exact storm coverage and overlap with the best fuels remains uncertain. ..Lyons.. 08/19/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0640 Status Updates
STATUS FOR WATCH 0640 HAS NOT BEEN ISSUED YET Read more

WW 640 SEVERE TSTM ID MT 192050Z - 200400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 640 NWS Storm Prediction Center Norman OK 250 PM MDT Mon Aug 19 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Idaho Western and Central Montana * Effective this Monday afternoon and evening from 250 PM until 1000 PM MDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...Thunderstorms are forming over the mountains of northern Idaho and western Montana. These storms will intensify and organize through the afternoon and spread northeastward across the watch area. Damaging wind gusts will be possible in the strongest storms. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 35 miles east southeast of Salmon ID to 35 miles northeast of Cut Bank 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. && OTHER WATCH INFORMATION...CONTINUE...WW 639... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 23025. ...Hart Read more

MD 1956 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR SOUTHEAST WYOMING...PARTS OF THE NEBRASKA PANHANDLE...AND MUCH OF EASTERN COLORADO
Mesoscale Discussion 1956 NWS Storm Prediction Center Norman OK 0219 PM CDT Mon Aug 19 2024 Areas affected...southeast Wyoming...parts of the Nebraska Panhandle...and much of eastern Colorado Concerning...Severe potential...Watch likely Valid 191919Z - 192045Z Probability of Watch Issuance...80 percent SUMMARY...Scattered strong to severe thunderstorms are expected this afternoon in the central High Plains with a threat for large hail and severe wind gusts. DISCUSSION...Moderate destabilization has occurred across eastern Colorado amid moist upslope flow (mid 60s dewpoints) and temperatures in the 80s. SPC mesoanalysis has indicated inhibition is decreasing along the Front Range. At least some inhibition is expected to remain across the Plains this afternoon which will likely limit storm initiation, however, scattered thunderstorm development is expected along the higher terrain which should intensify as it moves east into the more unstable airmass across the Plains this afternoon and evening. Mid-upper level flow of 30 to 40 knots combined with easterly flow at the surface will provide ample wind shear for some storm organization including the potential for a few supercells Despite the relatively warm temperatures aloft beneath the upper-ridge axis, steep lapse rates and the moderate shear should support some hail threat, especially early in the storm lifecycle when storm mode is more discrete. Later this afternoon and especially into the evening, expect the threat to transition to severe wind gusts with one or more clusters of storms which may develop out of the afternoon/early evening convection. ..Bentley/Hart.. 08/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 37890474 38540471 38970472 39720475 40790473 42110458 42450298 41310246 39900251 38220328 37520393 37890474 Read more

MD 1957 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR VIRGINIA AND PORTIONS OF NORTH CAROLINA
Mesoscale Discussion 1957 NWS Storm Prediction Center Norman OK 0224 PM CDT Mon Aug 19 2024 Areas affected...Virginia and portions of North Carolina Concerning...Severe potential...Watch unlikely Valid 191924Z - 192130Z Probability of Watch Issuance...20 percent SUMMARY...Scattered thunderstorm activity will have potential to produce downbursts with strong to severe gusts. DISCUSSION...Thunderstorm activity has increased in coverage across Virginia and North Carolina this afternoon as lift from a mid-level trough overspreads a cold front across the region. Breaks in morning cloud cover have allowed for sufficient daytime heating and temperatures in the mid to upper 80s, with low-level lapse rates around 8 C/km. MLCAPE around 1000-1500 J/kg is analyzed in RAP objective analysis. While deep layer shear is weak, steep lapse rates and precipitable water values above 1 inch will support potential for a few strong storms with potential for downbursts capable of strong to severe gusts. Overall, this threat will likely remain too localized for watch issuance. ..Thornton/Hart.. 08/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...AKQ...MHX...LWX...RAH...RNK... LAT...LON 36117983 36997936 38257821 38977726 39367670 39577629 39397579 38517527 37817552 36627595 35907616 35037641 34857648 35387934 36117983 Read more

MD 1958 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN MONTANA AND WESTERN NORTH DAKOTA.
Mesoscale Discussion 1958 NWS Storm Prediction Center Norman OK 0244 PM CDT Mon Aug 19 2024 Areas affected...Eastern Montana and western North Dakota. Concerning...Severe potential...Watch possible Valid 191944Z - 192115Z Probability of Watch Issuance...40 percent SUMMARY...Some intensification is possible as storms move northeast across eastern Montana. A watch may be needed. DISCUSSION...A slow moving cluster of storms has persisted across eastern Montana through most of the day today. Somewhat more robust convection has developed southeast of the primary cluster in the presence of greater instability (2000+ J/kg MLCAPE). SPC mesoanalysis shows inhibition has mostly eroded ahead of these storms and it should completely erode in the next 1 to 2 hours. A speed max overspread eastern Montana within the last hour (sampled 40-45 knots between 4-5km on the GGW VWP). This increase in deep layer shear may support an increase in storm intensity later this afternoon. A few thunderstorms capable of large hail and severe wind gusts are expected this evening. A severe thunderstorm watch may be needed. ..Bentley/Hart.. 08/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS...UNR...BYZ...GGW... LAT...LON 45850479 45840523 46080584 46390631 46660628 47860617 48570558 48940453 48670312 47360266 46180324 45800421 45850479 Read more

MD 1955 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NEW ENGLAND
Mesoscale Discussion 1955 NWS Storm Prediction Center Norman OK 0125 PM CDT Mon Aug 19 2024 Areas affected...portions of New England Concerning...Severe potential...Watch unlikely Valid 191825Z - 192030Z Probability of Watch Issuance...5 percent SUMMARY...Scattered thunderstorm activity may produce strong to severe gusts through the afternoon. DISCUSSION...Thunderstorm activity ongoing along and ahead of a cold front across portions of New England has shown an uptick in coverage over the last hour. Much of the region has been under mid-level cloud cover through the morning. However, a few breaks in the clouds have allowed temperatures to warm into the 80s with MLCAPE around 500-1000 J/kg. Deep layer shear for organization remains mostly offshore, with poor low to mid-level lapse rates. A few clusters of stronger storms may produce strong to severe gusts at times. Overall, the lack of support for organization of a more widespread severe threat will keep this threat localized precluding the need to for a watch. ..Thornton/Hart.. 08/19/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...BTV...OKX...ALY...PHI...BGM...CTP... LWX... LAT...LON 39177503 39167532 39297597 39877626 40557581 43067419 43987278 43997120 43827082 43107066 42647086 41797190 39317479 39177503 Read more