SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0732 AM CDT Fri Aug 30 2024 Valid 301300Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms are possible across eastern Lower Michigan this afternoon, with damaging winds the main threat. Isolated strong to severe thunderstorms may occur into parts of the Midwest, and also across portions of the Carolinas and Virginia into northeast Georgia. ...Great Lakes to the Mid Mississippi Valley... Weak/elevated thunderstorms ongoing this morning from parts of northern IL into Lower MI should continue to gradually weaken. In their wake, moderate instability should develop along and ahead of a cold front that will extend from the Upper Great Lakes region southwestward to the southern Plains by this afternoon. This front should make continued slow east-southeastward progress across these regions through the period as an upper trough moves eastward over Ontario, the Great Lakes, and Midwest. Stronger mid-level winds associated with this feature will generally remain confined to Canada. But, modest enhancement to the west-southwesterly low/mid-level flow should be present over parts of Lower MI this afternoon. Even though low-level convergence along the front should remain fairly weak, expectations are for at least scattered thunderstorms to develop along much of its length from eastern Lower MI to the mid MS Valley and southern Plains. The combination of moderate instability with modest deep-layer shear should promote some convective organization, with loosely organized multicells/clusters likely becoming the dominant thunderstorm mode. Steepened low-level lapse rates with daytime hearing should encourage occasional strong to damaging winds, with slightly stronger low/mid-level flow perhaps supporting a relatively greater threat ahead of the front in eastern Lower MI. Isolated hail may also occur with the strongest cores. Convection should weaken with time this evening with the loss of daytime heating. ...Southern Appalachians to the Southern Mid-Atlantic... Upper ridging will persist over the Southeast today. Very weak low/mid-level flow is expected to limit overall thunderstorm organization. Still, moderate instability should be present this afternoon as daytime heating occurs along and south of a stalled front over southern VA and northern NC. Even though deep-layer shear will remain negligible, pulse-type thunderstorms that develop in this moderately unstable and high precipitable water environment could produce isolated strong to damaging downburst winds this afternoon. ..Gleason/Leitman.. 08/30/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0335 AM CDT Fri Aug 30 2024 Valid 021200Z - 071200Z ...DISCUSSION... Global models appear to be in reasonable agreement through the medium range, with a long-wave upper trough crossing the eastern U.S. Day 4/Monday, and then shifting into the Canadian Maritimes and western Atlantic Day 5/Tuesday. Weak/low-amplitude flow aloft will prevail across the U.S. Day 5 and into Day 6/Wednesday, before the pattern begins to amplify again through Days 7-8 (Thursday and Friday, Sept. 5-6). This amplification anticipated late in the period will result in an eastern trough/western ridge configuration, with a cold front to progress across the eastern half of the country through the second half of the period. However, with the prior (Day 3) frontal advance across the southern U.S., and persistence of Canadian surface high pressure in its wake, rich/Gulf moisture is expected to remain confined to southern portions of the country. This should limit severe potential with the late-period system as it crosses the CONUS. As such, no severe-weather risk areas are being included in the forecast, as overall potential appears likely at this time to remain low through the end of the upcoming week. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0335 AM CDT Fri Aug 30 2024 Valid 021200Z - 071200Z ...DISCUSSION... Global models appear to be in reasonable agreement through the medium range, with a long-wave upper trough crossing the eastern U.S. Day 4/Monday, and then shifting into the Canadian Maritimes and western Atlantic Day 5/Tuesday. Weak/low-amplitude flow aloft will prevail across the U.S. Day 5 and into Day 6/Wednesday, before the pattern begins to amplify again through Days 7-8 (Thursday and Friday, Sept. 5-6). This amplification anticipated late in the period will result in an eastern trough/western ridge configuration, with a cold front to progress across the eastern half of the country through the second half of the period. However, with the prior (Day 3) frontal advance across the southern U.S., and persistence of Canadian surface high pressure in its wake, rich/Gulf moisture is expected to remain confined to southern portions of the country. This should limit severe potential with the late-period system as it crosses the CONUS. As such, no severe-weather risk areas are being included in the forecast, as overall potential appears likely at this time to remain low through the end of the upcoming week. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0233 AM CDT Fri Aug 30 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NEW ENGLAND TO THE CAROLINAS/SOUTHERN APPALACHIANS VICINITY... ...SUMMARY... Strong/isolated severe storms capable of producing gusty/damaging winds will be possible from New England to the Carolinas Sunday. ...Synopsis... A progressive/amplifying upper trough is forecast to continue shift eastward across eastern Canada/the eastern U.S. on Sunday, while upstream ridging prevails over the West. During the second half of the period (Sunday night), an eastern Pacific upper low should near/reach the Oregon/northern California Coast. At the surface, an initial cold front extending from New England to the Southeast will continue to dissipate. Meanwhile, a second/stronger front will continue shifting rapidly into the Northeast and across the Ohio Valley through the day, eventually overtaking the initial/weakening front. By Monday morning, the front will likely have moved off the New England and Mid-Atlantic Coasts, stretching westward from the Carolinas to Texas. ...New England to the Carolinas/southern Appalachians... As the reinforcing cold front advances quickly eastward/southeastward across the Northeast and central Appalachians Sunday, questions exist regarding potential for destabilization ahead of this front given the prior/dissipating front and associated convection lingering across the area at the start of the period. Presuming at least modest destabilization can occur, ascent along the advancing front combined with favorably strong flow aloft -- particularly across the Northeast -- would support fast-moving storms and attendant risk for damaging gusts through the afternoon and into the evening. While there are hints that sufficient moisture may linger across portions of New England to allow more substantial CAPE to evolve during the afternoon, which would yield greater severe potential, at this time uncertainty due to existing convection/cloud cover suggests that MRGL/5% risk remains most prudent at this time. ..Goss.. 08/30/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0115 AM CDT Fri Aug 30 2024 Valid 311200Z - 011200Z ...Synopsis... Fire weather concerns will remain confined to portions of the Great Basin for Saturday. Upper-level ridging currently over the western CONUS will begin to slowly shift east towards the central Rockies over the next 48-72 hours. As this occurs, a modest plume of monsoonal moisture will spread north/northwest into southeastern NV and southwest UT. Weak mid/upper-level ascent impinging on the fringe of the moisture plume should support isolated thunderstorms by late afternoon. A deep, well-mixed boundary layer will promote limited rainfall with this activity over a region with generally receptive fuels (ERC values at/above the 80th percentile). Consequently, dry lightning will be a fire weather concern. Elsewhere across the West, dry conditions will persist, and increasing mid-level flow along the West Coast may support some breezy conditions in the immediate lee of the central to southern Sierra Nevada. However, confidence in widespread elevated conditions remains too limited for highlights. ..Moore.. 08/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0115 AM CDT Fri Aug 30 2024 Valid 311200Z - 011200Z ...Synopsis... Fire weather concerns will remain confined to portions of the Great Basin for Saturday. Upper-level ridging currently over the western CONUS will begin to slowly shift east towards the central Rockies over the next 48-72 hours. As this occurs, a modest plume of monsoonal moisture will spread north/northwest into southeastern NV and southwest UT. Weak mid/upper-level ascent impinging on the fringe of the moisture plume should support isolated thunderstorms by late afternoon. A deep, well-mixed boundary layer will promote limited rainfall with this activity over a region with generally receptive fuels (ERC values at/above the 80th percentile). Consequently, dry lightning will be a fire weather concern. Elsewhere across the West, dry conditions will persist, and increasing mid-level flow along the West Coast may support some breezy conditions in the immediate lee of the central to southern Sierra Nevada. However, confidence in widespread elevated conditions remains too limited for highlights. ..Moore.. 08/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Fri Aug 30 2024 Valid 311200Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL APPALACHIANS AREA... ...SUMMARY... Severe potential -- mainly in the form of damaging gusts -- is expected across portions of the northeast/central Appalachians and into the Tennessee and Ohio Valleys Saturday. A few strong/severe gusts may also occur over parts of the Upper Mississippi Valley vicinity during the afternoon. ...Synopsis... An upper trough moving across central Canada and the Great Lakes region will amplify modestly as it progresses eastward through Saturday night. Meanwhile, large-scale upper ridging will continue to prevail over the West. At the surface, a weakening cold front will continue moving eastward across the Lower Great Lakes and Ohio Valley into the Northeast and Tennessee Valley area through Saturday afternoon and evening. Meanwhile, a much stronger cold front is forecast to shift rapidly southeastward/southward out of Canada across the Upper Great Lakes and northern/central Plains through the period. ...Portions of the Northeast west-southwestward across the Ohio and Tennessee Valleys... As a weakening cold front shifts southeastward into the Northeast/across the Ohio Valley during the afternoon in tandem with weak mid-level height falls, heating/destabilization will support development of bands of thunderstorms across this region. The strongest flow aloft will remain across New York and into Pennsylvania, with weaker flow southwestward along the front. However, more substantial CAPE is expected farther south/southwest. The best juxtaposition of favorable kinematics and ample instability is forecast from portions of southeastern New York southwestward into the West Virginia/Maryland/northern Virginia vicinity. Here, locally damaging winds and some hail will be possible -- particularly during the afternoon hours. Lesser risk will extend southwestward -- potentially as far west-southwest as the middle Mississippi Valley area. ...Upper Mississippi Valley vicinity... As a strong cold front advances south-southeastward across the Northern Plains/Upper Great Lakes region ahead of a digging mid-level short-wave through, weak/rather low-topped instability is forecast to develop during the afternoon. This will support widely scattered thunderstorm development near the advancing front, within a very favorably strong kinematic environment. As such, fast-moving storms will be capable of producing gusty/damaging winds locally, before storms diminish after sunset. ..Goss.. 08/30/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Fri Aug 30 2024 Valid 311200Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL APPALACHIANS AREA... ...SUMMARY... Severe potential -- mainly in the form of damaging gusts -- is expected across portions of the northeast/central Appalachians and into the Tennessee and Ohio Valleys Saturday. A few strong/severe gusts may also occur over parts of the Upper Mississippi Valley vicinity during the afternoon. ...Synopsis... An upper trough moving across central Canada and the Great Lakes region will amplify modestly as it progresses eastward through Saturday night. Meanwhile, large-scale upper ridging will continue to prevail over the West. At the surface, a weakening cold front will continue moving eastward across the Lower Great Lakes and Ohio Valley into the Northeast and Tennessee Valley area through Saturday afternoon and evening. Meanwhile, a much stronger cold front is forecast to shift rapidly southeastward/southward out of Canada across the Upper Great Lakes and northern/central Plains through the period. ...Portions of the Northeast west-southwestward across the Ohio and Tennessee Valleys... As a weakening cold front shifts southeastward into the Northeast/across the Ohio Valley during the afternoon in tandem with weak mid-level height falls, heating/destabilization will support development of bands of thunderstorms across this region. The strongest flow aloft will remain across New York and into Pennsylvania, with weaker flow southwestward along the front. However, more substantial CAPE is expected farther south/southwest. The best juxtaposition of favorable kinematics and ample instability is forecast from portions of southeastern New York southwestward into the West Virginia/Maryland/northern Virginia vicinity. Here, locally damaging winds and some hail will be possible -- particularly during the afternoon hours. Lesser risk will extend southwestward -- potentially as far west-southwest as the middle Mississippi Valley area. ...Upper Mississippi Valley vicinity... As a strong cold front advances south-southeastward across the Northern Plains/Upper Great Lakes region ahead of a digging mid-level short-wave through, weak/rather low-topped instability is forecast to develop during the afternoon. This will support widely scattered thunderstorm development near the advancing front, within a very favorably strong kinematic environment. As such, fast-moving storms will be capable of producing gusty/damaging winds locally, before storms diminish after sunset. ..Goss.. 08/30/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Fri Aug 30 2024 Valid 301200Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHEAST LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe storms are possible across eastern lower Michigan later today, with more isolated strong/severe storms into parts of the Midwest, and also across parts of the Carolinas and Virginia into northeast Georgia. ...Great Lakes/Midwest Region... Strong upper low, currently located over MB, will shift into northwest ON by the start of the period. Notable short-wave trough will advance from the upper MS Valley at 18z into the central Great Lakes by 31/12z. At the surface, synoptic front will advance into Lower MI-central IL-central OK by late afternoon. This boundary will serve as the focus for potential robust convection, especially as surface temperatures warm into the mid 80s. NAM forecast sounding for KDTW at 20z exhibits negligible CINH, with MLCAPE on the order of 2400 J/kg, though 0-6km bulk shear is seasonally weak. Deep-layer flow will increase a bit into the early evening hours, so updraft organization should be more favorable by this time. Even so, forecast lapse rates are marginal and this may limit overall severity. Southern extent of large-scale support should aid convective development ahead of the front. Some risk for wind/hail will exist with this activity. ...Southeast/Southern Middle Atlantic... Weak deep-layer flow will be noted across the southern Middle Atlantic and the Southeast today beneath the upper ridge. Boundary-layer heating will prove instrumental in convective development this afternoon, especially along a stalled synoptic front draped across NC/VA. Forecast soundings for this region suggest convective temperatures will be breached as early as 17z, and seasonally high PW values favor some risk for strong wind gusts within pulse-type updrafts. ..Darrow/Moore.. 08/30/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1242 AM CDT Fri Aug 30 2024 Valid 301200Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF SOUTHEAST LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe storms are possible across eastern lower Michigan later today, with more isolated strong/severe storms into parts of the Midwest, and also across parts of the Carolinas and Virginia into northeast Georgia. ...Great Lakes/Midwest Region... Strong upper low, currently located over MB, will shift into northwest ON by the start of the period. Notable short-wave trough will advance from the upper MS Valley at 18z into the central Great Lakes by 31/12z. At the surface, synoptic front will advance into Lower MI-central IL-central OK by late afternoon. This boundary will serve as the focus for potential robust convection, especially as surface temperatures warm into the mid 80s. NAM forecast sounding for KDTW at 20z exhibits negligible CINH, with MLCAPE on the order of 2400 J/kg, though 0-6km bulk shear is seasonally weak. Deep-layer flow will increase a bit into the early evening hours, so updraft organization should be more favorable by this time. Even so, forecast lapse rates are marginal and this may limit overall severity. Southern extent of large-scale support should aid convective development ahead of the front. Some risk for wind/hail will exist with this activity. ...Southeast/Southern Middle Atlantic... Weak deep-layer flow will be noted across the southern Middle Atlantic and the Southeast today beneath the upper ridge. Boundary-layer heating will prove instrumental in convective development this afternoon, especially along a stalled synoptic front draped across NC/VA. Forecast soundings for this region suggest convective temperatures will be breached as early as 17z, and seasonally high PW values favor some risk for strong wind gusts within pulse-type updrafts. ..Darrow/Moore.. 08/30/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Fri Aug 30 2024 Valid 301200Z - 311200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns are expected to remain limited for today across the country. Dry conditions will persist across much of the Great Basin and into parts of the Pacific Northwest and central Rockies for this afternoon with RH minimums once again falling into the teens and single digits. Upper-level ridging over the western CONUS will promote mostly clear skies but weak synoptic/gradient winds that should mitigate fire weather concerns. Thunderstorm activity along the lower CO River Valley on Thursday (yesterday) resulted in a mix of wet and dry thunderstorms based on sporadic rainfall measurements and MRMS QPE. A similar mix of wet/dry thunderstorms is expected again today across far southeast NV into western AZ as weak mid-level ascent overspreads the fringe of a modest monsoonal moisture plume. Latest fuel guidance suggests lightning ignition efficiency/fuel dryness gradually increases from far western AZ into southern NV, but the spatial coverage of sufficiently dry fuel with appreciable dry lightning threat appears too limited to introduce highlights. ..Moore.. 08/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1235 AM CDT Fri Aug 30 2024 Valid 301200Z - 311200Z ...NO CRITICAL AREAS... ...Synopsis... Fire weather concerns are expected to remain limited for today across the country. Dry conditions will persist across much of the Great Basin and into parts of the Pacific Northwest and central Rockies for this afternoon with RH minimums once again falling into the teens and single digits. Upper-level ridging over the western CONUS will promote mostly clear skies but weak synoptic/gradient winds that should mitigate fire weather concerns. Thunderstorm activity along the lower CO River Valley on Thursday (yesterday) resulted in a mix of wet and dry thunderstorms based on sporadic rainfall measurements and MRMS QPE. A similar mix of wet/dry thunderstorms is expected again today across far southeast NV into western AZ as weak mid-level ascent overspreads the fringe of a modest monsoonal moisture plume. Latest fuel guidance suggests lightning ignition efficiency/fuel dryness gradually increases from far western AZ into southern NV, but the spatial coverage of sufficiently dry fuel with appreciable dry lightning threat appears too limited to introduce highlights. ..Moore.. 08/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0662 Status Updates
STATUS REPORT ON WW 662 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 WNW MCW TO 35 N MCW. REMAINING VALID PORTION OF WW 662 MAY BE ALLOWED TO EXPIRE AT 30/02Z. ..KERR..08/30/24 ATTN...WFO...FSD...DLH...MPX...FGF... STATUS REPORT FOR WS 662 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS WIC107-300200- WI . WISCONSIN COUNTIES INCLUDED ARE RUSK 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

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 PM CDT Thu Aug 29 2024 Valid 300100Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE UPPER MIDWEST... ...SUMMARY... Thunderstorms, a few severe, will spread across the Upper Midwest this evening. Some risk for isolated wind/hail persists through about 04-05z. ...01z Update... Strong, well-defined upper low is lifting northeast across southern MB early this evening. Trailing trough extends across the eastern Dakotas with the southern most portion affecting western KS. This feature is largely responsible for an elongated band of convection across the Upper Midwest, arcing ahead of a synoptic front into the central Plains. The most organized portion of this linear MCS is advancing across western WI/southeast MN/IA. LLJ will shift east across IA/WI this evening, suggesting this activity will remain organized for several hours. Most supercell structures have been disorganized along the line, and damaging winds will likely be the primary severe threat, as large hail has been mostly absent with this convection. Scattered-numerous thunderstorm clusters persist across the Middle Atlantic region this evening. 00z soundings from this region exhibit modest lapse rates, but seasonally high PW values. Wind profiles are marginally supportive of organized updrafts so this activity has likely peaked in intensity. Aside from an isolated damaging wind/hail report, the overall severe threat should gradually diminish over the next few hours. ..Darrow.. 08/30/2024 Read more

WW 0664 Status Updates
STATUS FOR WATCH 0664 HAS NOT BEEN ISSUED YET Read more

WW 664 SEVERE TSTM IA MN WI 300050Z - 300400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 664 NWS Storm Prediction Center Norman OK 750 PM CDT Thu Aug 29 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Extreme northeast Iowa Extreme southeast Minnesota Southwest and west central Wisconsin * Effective this Thursday evening from 750 PM until 1100 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1 inch in diameter possible A tornado or two possible SUMMARY...A line of storms with a history of wind damage will continue eastward for the next few hours before weakening. An isolated tornado or two, as well as marginally severe hail, will also be possible with the more intense/embedded segments. The severe thunderstorm watch area is approximately along and 25 statute miles east and west of a line from 105 miles north northeast of La Crosse WI to 55 miles south of La Crosse WI. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU4). 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 662...WW 663... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26030. ...Thompson Read more

WW 0663 Status Updates
STATUS REPORT ON WW 663 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SSW CHO TO 40 S MRB TO 10 NNW DCA. ..KERR..08/30/24 ATTN...WFO...LWX...CTP... STATUS REPORT FOR WS 663 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS DCC001-300140- DC . DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE DISTRICT OF COLUMBIA MDC017-033-300140- MD . MARYLAND COUNTIES INCLUDED ARE CHARLES PRINCE GEORGES VAC013-047-059-061-099-137-153-177-179-510-600-610-630-683-685- 300140- VA . VIRGINIA COUNTIES INCLUDED ARE ARLINGTON CULPEPER FAIRFAX FAUQUIER KING GEORGE ORANGE PRINCE WILLIAM SPOTSYLVANIA STAFFORD Read more

WW 663 SEVERE TSTM DC MD PA VA WV CW 291955Z - 300300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 663 NWS Storm Prediction Center Norman OK 355 PM EDT Thu Aug 29 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of District Of Columbia Maryland South-Central Pennsylvania Northern Virginia Far Eastern West Virginia Coastal Waters * Effective this Thursday afternoon and evening from 355 PM until 1100 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible SUMMARY...Scattered storms will continue to increase, intensify, and potentially organize as they persist through early/mid-evening, with localized wind damage and some hail possible. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 50 miles north northwest of Harrisburg PA to 20 miles south of Staunton VA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). 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 662... AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 29020. ...Guyer Read more

MD 2033 CONCERNING SEVERE THUNDERSTORM WATCH 662...663... FOR PORTIONS OF THE MID ATLANTIC
Mesoscale Discussion 2033 NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Aug 29 2024 Areas affected...portions of the Mid Atlantic Concerning...Severe Thunderstorm Watch 662...663... Valid 292140Z - 292315Z The severe weather threat for Severe Thunderstorm Watch 662, 663 continues. SUMMARY...The severe threat continues across WW663. Clusters of strong to severe storms should continue into this evening. Damaging wind gusts and occasional hail are possible. DISCUSSION...As of 2130 UTC, several clusters of strong to severe storms were ongoing across WW633. Over the past several hours, these clusters have produced occasional damaging wind gusts and isolated severe hail. The environment across the watch area and much of the Mid Atlantic remains unstable and modestly sheared with 2000 J/kg of MLCAPE from SPC mesoanalysis and 20-25 kt of effective shear via area VADs. Convective coverage may increase slightly over the next coupe of hours as various outflows interact with ongoing and developing clusters. Damaging winds remain the most likely threat, though isolated hail is possible with the stronger updrafts given the degree of buoyancy. Hi-res guidance and the latest observational trends suggest the highest storm coverage may remain over parts of the MD/VA/PA border region this evening. This may support a locally greater corridor of severe risk as some of the ongoing clusters may consolidate further. However, this is uncertain, given the lack of more meaningful broad-scale forcing, and the severe risk remains across much of the watch. ..Lyons.. 08/29/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...AKQ...CTP...LWX...RNK...PBZ...RLX... LAT...LON 38368005 40407883 40917810 41047685 40947631 40727597 40447586 40237589 39777606 38597654 38147688 37787786 37627831 37527937 37588006 38368005 Read more

MD 2034 CONCERNING SEVERE THUNDERSTORM WATCH 662... FOR PARTS OF EASTERN MINNESOTA AND NORTHWESTERN WISCONSIN
Mesoscale Discussion 2034 NWS Storm Prediction Center Norman OK 0537 PM CDT Thu Aug 29 2024 Areas affected...parts of eastern Minnesota and northwestern Wisconsin Concerning...Severe Thunderstorm Watch 662... Valid 292237Z - 300030Z The severe weather threat for Severe Thunderstorm Watch 662 continues. SUMMARY...An organized squall line may continue to pose a risk for strong to severe wind gusts and, perhaps, a brief tornado or two, before gradually weakening across north central Wisconsin by 8-9 PM CDT. DISCUSSION...Cold surface ridging has been slow to lose influence across much of northern and eastern Wisconsin into Michigan and the adjacent Great Lakes. Although modest destabilization is ongoing along the warm front east-southeast of Minneapolis into the Madison WI vicinity, it is not clear how much longer low-level southeasterly inflow will be sufficiently unstable to maintain the more organized segment of the squall line now in the process of advancing into northwestern and west central Wisconsin. However, cyclonic mesoscale lower/mid-level circulations still evident within the line might maintain a risk for damaging surface gusts and perhaps a brief tornado or two another couple of hours, into the 00-01Z time. Given the 30-35+ kt northeasterly/easterly forward propagation, this risk may spread into portions of north central Wisconsin east of the severe weather watch area. However, it is not yet clear that a new severe weather watch will be needed. ..Kerr.. 08/29/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...ARX...MPX... LAT...LON 45929231 46189231 46499110 45689024 44709048 43859137 44049255 44419279 45279233 45929231 Read more