MD 1870 CONCERNING TORNADO WATCH 615... FOR MIDDLE ATLANTIC
Mesoscale Discussion 1870 NWS Storm Prediction Center Norman OK 0738 PM CDT Thu Aug 08 2024 Areas affected...Middle Atlantic Concerning...Tornado Watch 615... Valid 090038Z - 090245Z The severe weather threat for Tornado Watch 615 continues. SUMMARY...Tornado risk continues with supercells this evening. DISCUSSION...Remnants of Debby have moved well inland and the center of circulation is now located over western NC, east of CLT. LLJ is strengthening across the middle Atlantic with latest model guidance suggesting this will continue through sunrise as LLJ translates into northern VA/MD/southern PA. Latest VAD data supports this with 0-3km SRH now in excess of 300 m2/s2 at LWX. Numerous small supercells are embedded within a larger precip shield, supported by moist low-level warm advection. Radar data suggests several of the more robust circulations have possibly produced tornadoes at times. While strong shear persists across portions of the Carolinas, with time the primary focus for organized supercells will begin to shift north across VA into MD. ..Darrow.. 08/09/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...AKQ...MHX...LWX...RAH...RNK... LAT...LON 35447858 39567876 39567614 35437609 35447858 Read more

WW 0615 Status Updates
STATUS REPORT ON WW 615 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SPC..08/09/24 ATTN...WFO...LWX...MHX...AKQ...RNK...RAH... STATUS REPORT FOR WT 615 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS DCC001-090240- DC . DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE DISTRICT OF COLUMBIA MDC003-005-009-013-015-017-021-025-027-031-033-037-043-510- 090240- MD . MARYLAND COUNTIES INCLUDED ARE ANNE ARUNDEL BALTIMORE CALVERT CARROLL CECIL CHARLES FREDERICK HARFORD HOWARD MONTGOMERY PRINCE GEORGES ST. MARYS WASHINGTON MARYLAND INDEPENDENT CITIES INCLUDED ARE BALTIMORE CITY Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 PM CDT Thu Aug 08 2024 Valid 090100Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID ATLANTIC... ...SUMMARY... An isolated tornado threat will continue tonight across parts of the Mid Atlantic. Strong thunderstorm wind gusts may affect parts of Utah and Arizona. ...Mid Atlantic... Tropical Depression Debby will continue to move northward across west-central North Carolina this evening and into southern Virginia tonight. The main rainband associated with Debby is located from western and northern Virginia into Maryland. Corridors with more discrete convection are located across southern Virginia and eastern North Carolina. These three convective areas are located to the north and east of Debby's center, where the RAP suggests that 850 mb flow is generally in the 40 to 50 knot range. The WSR-88D VWP at Richmond, Virginia is sampling the stronger flow, with about 50 knots at 2 km. This is contributing to 0-3 km storm-relative helicity of 450 to 500 m2/s2, which will continue to support a tornado threat with the discrete or semi-discrete storms that develop within this strong low-level flow. The potential for tornadoes could continue into the late evening or early overnight period, as Debby moves into southern Virginia. ...Desert Southwest... Scattered to widely scattered monsoon thunderstorms are ongoing across much of the Desert Southwest early this evening. Surface dewpoints across west-central Arizona and southern Utah are in the 50s and lower 60 F, which is contributing to weak instability. In spite of this, low-level lapse rates are still steep in some areas. This is evident on RAP forecast soundings, which maintain 0-3 km lapse rates in the 7 to 8 C/km range across some of the region through mid to late evening. For this reason, a few of the stronger storms could produce marginally severe wind gusts. ..Broyles.. 08/09/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0752 PM CDT Thu Aug 08 2024 Valid 090100Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE MID ATLANTIC... ...SUMMARY... An isolated tornado threat will continue tonight across parts of the Mid Atlantic. Strong thunderstorm wind gusts may affect parts of Utah and Arizona. ...Mid Atlantic... Tropical Depression Debby will continue to move northward across west-central North Carolina this evening and into southern Virginia tonight. The main rainband associated with Debby is located from western and northern Virginia into Maryland. Corridors with more discrete convection are located across southern Virginia and eastern North Carolina. These three convective areas are located to the north and east of Debby's center, where the RAP suggests that 850 mb flow is generally in the 40 to 50 knot range. The WSR-88D VWP at Richmond, Virginia is sampling the stronger flow, with about 50 knots at 2 km. This is contributing to 0-3 km storm-relative helicity of 450 to 500 m2/s2, which will continue to support a tornado threat with the discrete or semi-discrete storms that develop within this strong low-level flow. The potential for tornadoes could continue into the late evening or early overnight period, as Debby moves into southern Virginia. ...Desert Southwest... Scattered to widely scattered monsoon thunderstorms are ongoing across much of the Desert Southwest early this evening. Surface dewpoints across west-central Arizona and southern Utah are in the 50s and lower 60 F, which is contributing to weak instability. In spite of this, low-level lapse rates are still steep in some areas. This is evident on RAP forecast soundings, which maintain 0-3 km lapse rates in the 7 to 8 C/km range across some of the region through mid to late evening. For this reason, a few of the stronger storms could produce marginally severe wind gusts. ..Broyles.. 08/09/2024 Read more

No Mesoscale Discussions are in effect as of Thu Aug 8 22:36:15 UTC 2024.

WW 0615 Status Updates
STATUS FOR WATCH 0615 HAS NOT BEEN ISSUED YET Read more

WW 615 TORNADO DC MD NC VA WV CW 082235Z - 091100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 615 NWS Storm Prediction Center Norman OK 635 PM EDT Thu Aug 8 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of District Of Columbia Maryland Eastern North Carolina Central and eastern Virginia The eastern West Virginia Panhandle Coastal Waters * Effective this Thursday night and Friday morning from 635 PM until 700 AM EDT. * Primary threats include... A few tornadoes possible SUMMARY...Convective bands with embedded supercells and the potential for a few tornadoes will persist overnight and spread northward from North Carolina into Virginia/Maryland with the remnants of tropical cyclone Debby. The tornado watch area is approximately along and 70 statute miles east and west of a line from 30 miles east northeast of Martinsburg WV to 35 miles east of Goldsboro NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && OTHER WATCH INFORMATION...This tornado watch replaces tornado watch number 614. Watch number 614 will not be in effect after 635 PM EDT. AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 50 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 17035. ...Thompson Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0424 PM CDT Thu Aug 08 2024 Valid 101200Z - 161200Z A mid-level longwave trough is expected to amplify over the northwestern CONUS through the period. Various shortwave troughs around the periphery of this longwave trough may provide a focus for fire weather concerns over the weekend through early next week. ...D3/Saturday... A shortwave trough traversing the flow on Saturday may provide lift for thunderstorm activity across parts of the northern Rockies with precipitable water in the 0.5-0.75 inch range. Fuels in this region have received relatively little rain recently, and so should be receptive to new ignitions. Therefore, a 10% Isolated Dry Thunder area was added here to reflect the dry lightning risk. Farther west across portions of southern Idaho and northeastern Nevada, a 40% Critical highlight has been maintained with low RH and a corridor of strong surface winds. ...D4/Sunday through D6/Tuesday... Another shortwave trough embedded in the flow may provide corridors for strong winds in the presence of generally low RH and receptive fuels across much of the Great Basin region Sunday through Tuesday. The highest confidence for this is on D5/Monday, and a 40% Critical highlight has been maintained across portions of eastern Nevada to reflect this. Additional highlights may need to be introduced for Sunday and/or Tuesday in subsequent outlooks if confidence in Elevated or Critical fire conditions increases. ..Supinie.. 08/08/2024 ...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 0424 PM CDT Thu Aug 08 2024 Valid 101200Z - 161200Z A mid-level longwave trough is expected to amplify over the northwestern CONUS through the period. Various shortwave troughs around the periphery of this longwave trough may provide a focus for fire weather concerns over the weekend through early next week. ...D3/Saturday... A shortwave trough traversing the flow on Saturday may provide lift for thunderstorm activity across parts of the northern Rockies with precipitable water in the 0.5-0.75 inch range. Fuels in this region have received relatively little rain recently, and so should be receptive to new ignitions. Therefore, a 10% Isolated Dry Thunder area was added here to reflect the dry lightning risk. Farther west across portions of southern Idaho and northeastern Nevada, a 40% Critical highlight has been maintained with low RH and a corridor of strong surface winds. ...D4/Sunday through D6/Tuesday... Another shortwave trough embedded in the flow may provide corridors for strong winds in the presence of generally low RH and receptive fuels across much of the Great Basin region Sunday through Tuesday. The highest confidence for this is on D5/Monday, and a 40% Critical highlight has been maintained across portions of eastern Nevada to reflect this. Additional highlights may need to be introduced for Sunday and/or Tuesday in subsequent outlooks if confidence in Elevated or Critical fire conditions increases. ..Supinie.. 08/08/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0614 Status Updates
STATUS REPORT ON WW 614 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SPC..08/08/24 ATTN...WFO...MHX...AKQ...RAH...RNK... STATUS REPORT FOR WT 614 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC013-015-029-031-041-049-053-055-061-063-065-069-073-077-079- 083-091-095-101-103-107-117-127-131-133-137-139-143-145-147-177- 181-183-185-187-191-195-082240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BEAUFORT BERTIE CAMDEN CARTERET CHOWAN CRAVEN CURRITUCK DARE DUPLIN DURHAM EDGECOMBE FRANKLIN GATES GRANVILLE GREENE HALIFAX HERTFORD HYDE JOHNSTON JONES LENOIR MARTIN NASH NORTHAMPTON ONSLOW PAMLICO PASQUOTANK PERQUIMANS PERSON PITT TYRRELL VANCE WAKE WARREN WASHINGTON WAYNE WILSON VAC007-011-025-029-031-033-036-037-041-049-053-057-065-073-075- 081-083-085-087-093-095-097-101-109-111-115-117-119-127-135-145- 147-149-175-181-183-199-550-570-595-620-650-670-680-700-710-730- 735-740-760-800-810-830-082240- Read more

WW 0614 Status Updates
STATUS REPORT ON WW 614 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SPC..08/08/24 ATTN...WFO...MHX...AKQ...RAH...RNK... STATUS REPORT FOR WT 614 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NCC013-015-029-031-041-049-053-055-061-063-065-069-073-077-079- 083-091-095-101-103-107-117-127-131-133-137-139-143-145-147-177- 181-183-185-187-191-195-082240- NC . NORTH CAROLINA COUNTIES INCLUDED ARE BEAUFORT BERTIE CAMDEN CARTERET CHOWAN CRAVEN CURRITUCK DARE DUPLIN DURHAM EDGECOMBE FRANKLIN GATES GRANVILLE GREENE HALIFAX HERTFORD HYDE JOHNSTON JONES LENOIR MARTIN NASH NORTHAMPTON ONSLOW PAMLICO PASQUOTANK PERQUIMANS PERSON PITT TYRRELL VANCE WAKE WARREN WASHINGTON WAYNE WILSON VAC007-011-025-029-031-033-036-037-041-049-053-057-065-073-075- 081-083-085-087-093-095-097-101-109-111-115-117-119-127-135-145- 147-149-175-181-183-199-550-570-595-620-650-670-680-700-710-730- 735-740-760-800-810-830-082240- Read more

MD 1867 CONCERNING TORNADO WATCH 614... FOR EASTERN NORTH CAROLINA INTO SOUTHEASTERN VIRGINIA
Mesoscale Discussion 1867 NWS Storm Prediction Center Norman OK 0212 PM CDT Thu Aug 08 2024 Areas affected...eastern North Carolina into southeastern Virginia Concerning...Tornado Watch 614... Valid 081912Z - 082115Z The severe weather threat for Tornado Watch 614 continues. SUMMARY...Brief tornado risk continues across portions of Tornado Watch 614. DISCUSSION...Recent radar loop shows little movement of the center of Tropical Storm Debby (still in the vicinity of the North Carolina/South Carolina border southeast of Charlotte, NC), while individual cells in convective bands within the northeastern quadrant of the storm having become a bit stronger in general over the past couple of hours. This intensification is likely related to modest heating through some cloud breaks, that has allowed weak destabilization/small increases in mixed-layer CAPE to occur. In tandem with this cellular increase, and given the favorable background low-level flow field, an uptick in coverage of storms exhibiting low-level rotation has been observed overall. The most active area in terms of low-level circulations has been in the vicinity of the northeastern North Carolina/southeastern Virginia border region, where rotating cells continue moving northwestward, along with occasional radar hints of potential/brief tornadoes. Overall, expect the situation to remain generally steady-state, with continued risk for brief tornadoes likely to persist over the next several hours. ..Goss.. 08/08/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM...RNK... LAT...LON 34517765 35407806 36367868 37207841 37507760 37297682 36597618 35287590 34257660 34517765 Read more

MD 1868 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN UTAH INTO WESTERN AND CENTRAL ARIZONA
Mesoscale Discussion 1868 NWS Storm Prediction Center Norman OK 0221 PM CDT Thu Aug 08 2024 Areas affected...Southern Utah into western and central Arizona Concerning...Severe potential...Watch unlikely Valid 081921Z - 082115Z Probability of Watch Issuance...20 percent SUMMARY...Scattered high-based thunderstorms are likely near the higher terrain and ahead of a weak MCV this afternoon/evening. Isolated damaging gusts are possible. Limited storm organization suggests a WW is not expected. DISCUSSION...As of 1915 UTC, regional visible and radar imagery showed initial thunderstorm development was ongoing over the higher terrain of southern UT and across central AZ. Linked to robust monsoonal moisture return and an MCV beneath an expansive western US ridge, additional storm development is likely through the afternoon hours. As remaining inhibition weakens, 500-1000 J/kg of MUCAPE will support scattered high-based thunderstorms across the higher terrain of southern UT and ahead of a weak MCV over central AZ. PWATs of 0.7-1 inch and relatively deep inverted-V profiles from area model soundings will favor strong downdrafts with some potential for damaging outflow winds as storms become established. However, area VADs show flow aloft is quite limited (generally less than 20 kt) beneath the ridge. Given the limited shear, a relatively disorganized multi-cell storm mode is expected to limit the severe risk. Given the limited organization potential a WW is unlikely at this time. ..Lyons/Hart.. 08/08/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ...SLC...PSR...VEF... LAT...LON 36931405 38611328 38801303 39171174 38921043 38511012 37671053 36511149 35871180 35261154 34271065 33840984 33250982 31601041 31711119 31821138 32121193 32641257 33731347 34721405 36931405 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0232 PM CDT Thu Aug 08 2024 Valid 082000Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO THE MID-ATLANTIC... ...SUMMARY... Isolated tornadoes are possible today and tonight over portions of the Mid Atlantic region. Strong thunderstorm wind gusts may affect portions of Utah and Arizona. ...20Z Update... Overall, no changes are needed for this outlook. ...Mid Atlantic... As mentioned in recently issued MCD #1867, Tropical Storm Debby continues to move slowly northwestward, while individual cells in convective bands within the northeastern quadrant of the storm have become a bit stronger in general over the past couple of hours. Given the favorable background low-level flow field, an uptick in coverage of storms exhibiting low-level rotation has been observed, and a continued risk for brief tornadoes will likely to persist over the next several hours. ...UT/AZ... Scattered high-based thunderstorms near the higher terrain and ahead of a weak MCV are still expected this afternoon/evening, with isolated damaging gusts are possible. ..Mosier.. 08/08/2024 .PREV DISCUSSION... /ISSUED 1105 AM CDT Thu Aug 08 2024/ ...Mid Atlantic... The center of circulation of TS Debby will lift northward today and tonight across central NC/VA, with the zone of strongest low level winds/shear just to the northeast of the low. A consensus of 12z CAM solutions suggest the main threat of semi-discrete convection and a few tornadoes this afternoon and evening will be across north-central NC and south-central VA. This threat will build northward into parts of northern VA and the Eastern WV Panhandle after dark, and eventually into central PA by Friday morning. Please refer to MCD #1866 for further short-term details. ...UT/AZ... Pockets of strong heating, ample mid-level moisture, and a remnant MCV tracking westward across northern AZ will help to promote thunderstorms capable of locally damaging wind gusts this afternoon from western UT into northwest AZ. Morning surface analysis shows a very moist boundary-layer in place across central and southeast AZ, with dewpoints in the upper 60s and full sunshine expected. This, combined with 12z CAM solutions of active afternoon thunderstorms, has prompted an expansion of the MRGL risk into that region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0232 PM CDT Thu Aug 08 2024 Valid 082000Z - 091200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NC INTO THE MID-ATLANTIC... ...SUMMARY... Isolated tornadoes are possible today and tonight over portions of the Mid Atlantic region. Strong thunderstorm wind gusts may affect portions of Utah and Arizona. ...20Z Update... Overall, no changes are needed for this outlook. ...Mid Atlantic... As mentioned in recently issued MCD #1867, Tropical Storm Debby continues to move slowly northwestward, while individual cells in convective bands within the northeastern quadrant of the storm have become a bit stronger in general over the past couple of hours. Given the favorable background low-level flow field, an uptick in coverage of storms exhibiting low-level rotation has been observed, and a continued risk for brief tornadoes will likely to persist over the next several hours. ...UT/AZ... Scattered high-based thunderstorms near the higher terrain and ahead of a weak MCV are still expected this afternoon/evening, with isolated damaging gusts are possible. ..Mosier.. 08/08/2024 .PREV DISCUSSION... /ISSUED 1105 AM CDT Thu Aug 08 2024/ ...Mid Atlantic... The center of circulation of TS Debby will lift northward today and tonight across central NC/VA, with the zone of strongest low level winds/shear just to the northeast of the low. A consensus of 12z CAM solutions suggest the main threat of semi-discrete convection and a few tornadoes this afternoon and evening will be across north-central NC and south-central VA. This threat will build northward into parts of northern VA and the Eastern WV Panhandle after dark, and eventually into central PA by Friday morning. Please refer to MCD #1866 for further short-term details. ...UT/AZ... Pockets of strong heating, ample mid-level moisture, and a remnant MCV tracking westward across northern AZ will help to promote thunderstorms capable of locally damaging wind gusts this afternoon from western UT into northwest AZ. Morning surface analysis shows a very moist boundary-layer in place across central and southeast AZ, with dewpoints in the upper 60s and full sunshine expected. This, combined with 12z CAM solutions of active afternoon thunderstorms, has prompted an expansion of the MRGL risk into that region. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0224 PM CDT Thu Aug 08 2024 Valid 091200Z - 101200Z A few tweaks were made to the Isolated Dry Thunder area across western Montana to account for recent precipitation and impact to fuel moisture. Otherwise, the previous forecast remains on track. ..Supinie.. 08/08/2024 .PREV DISCUSSION... /ISSUED 0155 AM CDT Thu Aug 08 2024/ ...Synopsis... A shortwave trough will traverse the northern periphery of the western US ridge on Friday with a modest increase in moisture across the Pacific Northwest, mainly west of the Cascades. Along the high terrain of the Cascades, isolated dry thunderstorms will be possible with precipitable water values forecast to be around 0.50-0.75 in. While some mix of wet/dry thunderstorms may evolve, fuels in this region are critically dry and will support new ignitions. Further isolated thunderstorm development is expected across Idaho into southwestern Montana, western Wyoming, and northern Utah. Precipitable water values are expected to be around 0.50-0.60 inch with very dry low-level profiles. This will support high-based storms with little to no precipitation. Fuels within this region remain in the 80th-90th percentile for dryness and receptive to new ignitions. ...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 0224 PM CDT Thu Aug 08 2024 Valid 091200Z - 101200Z A few tweaks were made to the Isolated Dry Thunder area across western Montana to account for recent precipitation and impact to fuel moisture. Otherwise, the previous forecast remains on track. ..Supinie.. 08/08/2024 .PREV DISCUSSION... /ISSUED 0155 AM CDT Thu Aug 08 2024/ ...Synopsis... A shortwave trough will traverse the northern periphery of the western US ridge on Friday with a modest increase in moisture across the Pacific Northwest, mainly west of the Cascades. Along the high terrain of the Cascades, isolated dry thunderstorms will be possible with precipitable water values forecast to be around 0.50-0.75 in. While some mix of wet/dry thunderstorms may evolve, fuels in this region are critically dry and will support new ignitions. Further isolated thunderstorm development is expected across Idaho into southwestern Montana, western Wyoming, and northern Utah. Precipitable water values are expected to be around 0.50-0.60 inch with very dry low-level profiles. This will support high-based storms with little to no precipitation. Fuels within this region remain in the 80th-90th percentile for dryness and receptive to new ignitions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1210 PM CDT Thu Aug 08 2024 Valid 091200Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN PA...NJ...AND THE NORTHERN DELMARVA PENINSULA... ...SUMMARY... There may be at least some continuing risk for damaging gusts tornadoes in advance of the remnant low of Debby. Greatest severe potential is expected from eastern Pennsylvania into New Jersey and the northern Delmarva Peninsula. ...Synopsis... A mid-latitude cyclone is forecast to begin the period over central Ontario before shifting gradually throughout the day. Moderate to strong flow is anticipated throughout the base of this cyclone, spreading from the Upper Midwest across the Great Lakes and OH Valley and into the Northeast as a shortwave trough progresses from the Upper Midwest across the Upper Great Lakes into southwest Quebec. Overall evolution of this cyclone and associated shortwave trough will interact with Tropical Cyclone Debby, which may be in its extratropical phase by early Friday morning. This interaction will result in an accelerated northeastward progression of Debby, taking it from its initial position near the WV/MD/VA border vicinity quickly northeastward through the Northeast and into the Upper St. Lawrence Valley by early Saturday. Farther west, dampened upper ridging will persist across the Southwest and southern Plains. A convectively generated, low-amplitude shortwave trough is forecast to move through the northern periphery of this ridging, from eastern CO into the Mid-South. Another low-amplitude shortwave trough may follow in the wake of the first, reaching the central KS/western OK by early Saturday morning. ...Mid-Atlantic into the Northeast... Robust low to mid-level flow is forecast to extend throughout the eastern periphery of TC Debby, from eastern NC into southern ME, early Friday morning. This strong flow will persist throughout the day, gradually shifting northeastward with the parent system. The strongest low/mid-level flow (i.e. 50+ kt at 850mb) will remain in close proximity to the cyclone, spreading from far northeast VA/central MD early Friday into eastern PA/NJ by the afternoon and into southern New England by late Friday/early Saturday Widespread cloud cover and limited heating is anticipated across the region, but deep convection still appears possible amid the strong warm-air advection. Buoyancy will be limited, likely tempering the overall updraft strength within this convection. However, ample moisture will be in place, which should combine with the strong low-level shear to support some organized storm structures. Damaging gusts will be the greatest severe threat, but embedded circulations could be strong enough to produce brief tornadoes as well. Highest severe potential is expected from eastern PA to the I-95 corridor in NJ, where the timing of the system allows for the best overlap between the buoyancy/daytime heating and the low-level shear. Strong forcing could still result in some damaging gusts farther north into NY and western New England, despite very limited buoyancy. Buoyancy will be greater farther south across eastern VA/NC, but shear will be weaker, likely keeping the severe threat isolated. ...Northeast NM/Southeast CO into TX Panhandle and Western OK... Scattered showers and thunderstorms will likely be ongoing across the TX Panhandle vicinity early Friday, with some potential that this activity will persist downstream into western OK throughout the day. Limited buoyancy and shear should keep the severe threat low. Another round of thunderstorms is possible Friday afternoon, beginning in the Raton Mesa vicinity and then continuing eastward/southeastward through the evening and potentially overnight, maintained by a moderate low-level jet across west TX. As with the early morning storms, limited buoyancy and shear should keep the severe threat low. ..Mosier.. 08/08/2024 Read more

MD 1866 CONCERNING TORNADO WATCH 613... FOR EASTERN NORTH CAROLINA INTO SOUTHEASTERN VIRGINIA
Mesoscale Discussion 1866 NWS Storm Prediction Center Norman OK 1018 AM CDT Thu Aug 08 2024 Areas affected...eastern North Carolina into southeastern Virginia Concerning...Tornado Watch 613... Valid 081518Z - 081715Z The severe weather threat for Tornado Watch 613 continues. SUMMARY...Local risk for brief tornadoes will continue, north and east of the center of T.S. Debby. DISCUSSION...Latest radar loop shows low-topped, occasionally rotating convective cells moving northwestward across eastern North Carolina, within the northeast quadrant of Debby(now centered over northeastern South Carolina). A lack of inland lightning is currently observed, reflecting the weak CAPE within the tropical environment revealed by area/morning RAOBs. With that said, a very favorable low-level wind field is also indicated, with flow veering and increasing notable with height through the lower portion of the troposphere, reaching/exceeding 50 kt from the southeast at 800m to 1000m AGL. This is providing a favorable environment for occasional, and briefly strong -- low-level spin-ups, and expect this trend to continue through the day today. With WW 613 set to expire at 08/17Z, a new tornado watch will be needed, extending farther northward to include central Virginia. ..Goss.. 08/08/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM... LAT...LON 34077719 34797802 35267822 36067886 36337881 36627856 36487740 36007673 35207594 34487604 34117680 34077719 Read more

WW 0614 Status Updates
STATUS FOR WATCH 0614 HAS NOT BEEN ISSUED YET Read more