SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0501 PM CDT Tue Aug 06 2024 Valid 081200Z - 141200Z The subtropical ridge will remain entrenched over much of the southern half of CONUS with a modest belt of westerly flow across the northern half of CONUS through the weekend into early next week. Extended-range global guidance has a signal for convective precipitation with monsoon moisture on D3/Thursday and D4/Friday across portions of the Great Basin. This precipitation would occur in a region with precipitable water values between 0.5-0.75 inches, which would present a risk for dry lightning. Fuels in the region are receptive to fire spread, pending any wetting rains from previous day's convection. Therefore, the 10% Dry Thunder area is maintained for D3. However, the risk on D4 may be more marginal, so have held off on introducing a 10% Dry Thunder area on D4 for now. Otherwise, despite low RH, winds through D4 look to be a bit too marginal to have confidence in introducing 40% highlights at this time. A weak mid-level shortwave trough traversing the northwestern CONUS on D5/Saturday may provide a focus for a corridor of stronger surface winds across portions of southern Idaho and northeastern Nevada. Since this is colocated with stronger winds and at least modestly receptive fuels, a 40% area has been maintained in this outlook in this region. Additional days with critical fire conditions are possible later in the week across portions of the Great Basin, however confidence is too low to highlight specific areas right now. ..Supinie.. 08/06/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1847 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR WESTERN AND CENTRAL MONTANA INTO NORTHERN WYOMING
Mesoscale Discussion 1847 NWS Storm Prediction Center Norman OK 0315 PM CDT Tue Aug 06 2024 Areas affected...Western and Central Montana into Northern Wyoming Concerning...Severe potential...Watch possible Valid 062015Z - 062245Z Probability of Watch Issuance...60 percent SUMMARY...A severe thunderstorm watch may be needed across portions of central and western Montana, as well as portions of northern Wyoming, later this afternoon or early evening... primarily for damaging winds and hail. DISCUSSION...Scattered convection has developed over portions of Idaho and Montana ahead of a mid-level shortwave trough, progressing eastward from OR/WA. Current SPC Mesoanalysis and forecast proximity soundings suggests that the ongoing convection in Montana is rooted above the boundary-layer, but may later become surface based as the boundary-layer continues to mix throughout the afternoon. Recent satellite trends suggests additional convective development over far eastern ID and western MT is likely, which will move eastward into central MT this afternoon and evening. Ongoing convection in far northwestern WY, where surface-based CINH has eroded, will also move eastward into north-central and northeastern WY. Convection is expected to be high-based, with MLLCL heights ranging from 2-3 km in height due to modest dewpoints in the low-to-mid 50s F. However, MLCAPE values exceeding 1000 J/kg, coupled with deep-layer shear values between 35-45 kts (owing to mostly straight-line hodographs), will support organized convective clusters and high-based supercell thunderstorms. Due to the high based nature of convection, and relatively dry boundary layer profiles, damaging straight-line winds from thunderstorm outflow will be possible. Additionally, any organized supercells will be capable of large hail. A severe thunderstorm watch may be needed later this afternoon and into the evening. ..Halbert/Lyons/Hart.. 08/06/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR...BYZ...GGW...RIW...TFX... LAT...LON 45330964 46331172 46851245 47461289 48241276 48961261 48981011 48950843 48330764 47280661 46380587 44630509 44100523 43820565 43840640 44190723 44670814 45330964 Read more

MD 1848 CONCERNING SEVERE THUNDERSTORM WATCH 605...606... FOR PORTIONS OF EASTERN OHIO AND MUCH OF PENNSYLVANIA AND NEW JERSEY
Mesoscale Discussion 1848 NWS Storm Prediction Center Norman OK 0329 PM CDT Tue Aug 06 2024 Areas affected...portions of eastern Ohio and much of Pennsylvania and New Jersey Concerning...Severe Thunderstorm Watch 605...606... Valid 062029Z - 062130Z The severe weather threat for Severe Thunderstorm Watch 605, 606 continues. SUMMARY...The severe threat continues across Severe Thunderstorm Watches 605-606. Damaging gusts should remain the primary threat, though a couple instances of large hail are possible and a tornado still cannot be ruled out. DISCUSSION...At least three linear convective complexes have organized across northern OH into PA and NJ over the last few hours, with the north OH and central PA complexes having a history of producing strong, damaging gusts. A radar-indicated tornado also occurred with a QLCS circulation just south of Cleveland, OH. The western lines of storms are progressive, with the central PA line of storms having the most residence time within an ambient unstable airmass characterized by 85-90 F surface temperatures and up to 2000 J/kg MLCAPE. However, the northern OH complex is poised to overspread a convectively overturned airmass over the next few hours, which may dampen the severe threat to a degree. In the meantime (i.e. next couple of hours), an additional QLCS tornado may still occur given the presence of mesovortices established in the leading-line of convection. Storms in southeast PA into NJ are not as progressive, and they have been overturning the airmass in the region, which may limit the severe threat with the central PA storms as they approach this worked over airmass. ..Squitieri.. 08/06/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...BGM...CTP...LWX...PBZ...CLE...ILN... LAT...LON 41448295 41878061 41477492 40527374 39927391 39567532 39757871 40038122 40248233 40678325 41448295 Read more

MD 1849 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR CENTRAL AND SOUTHERN ARIZONA
Mesoscale Discussion 1849 NWS Storm Prediction Center Norman OK 0344 PM CDT Tue Aug 06 2024 Areas affected...Central and Southern Arizona Concerning...Severe potential...Watch possible Valid 062044Z - 062245Z Probability of Watch Issuance...40 percent SUMMARY...Some severe thunderstorms will be possible across central and southern Arizona this afternoon and evening, capable of primarily damaging straight-line winds. Watch issuance remains uncertain at this time, given uncertainty in future convective development and organization. DISCUSSION...Thunderstorms have developed over the Mogollon Rim in Arizona, where daytime heating has resulted in surface temperatures in the mid-to-upper 90s F at the top of the rim, and low-to-mid 100s F down in the lower desert. Deep inverted-v boundary-layer profiles and generally weak flow aloft will support damaging wind gusts from thunderstorm outflow. Current upper-air analyses and water vapor satellite trends suggest a belt of modest 20-25 kt easterly flow beginning to overspread central and southern Arizona, which could aid in convective organization and an increased severe threat. However, given convection has yet to move off of the Mogollon Rim, there is significant uncertainty in the magnitude of convective organization that can be expected. ..Halbert/Lyons/Hart.. 08/06/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ...PSR...VEF... LAT...LON 34571408 35221360 35641309 35661222 35491175 35111146 34761117 34471106 33991112 33471121 32981154 32461199 32241278 32331359 32471371 32911401 33421416 33851421 34571408 Read more

WW 0605 Status Updates
STATUS REPORT ON WW 605 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BROYLES..08/06/24 ATTN...WFO...CLE...PBZ...CTP... STATUS REPORT FOR WS 605 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OHC005-007-013-019-029-031-033-035-043-055-059-063-067-075-077- 081-083-085-093-099-101-103-117-133-139-151-153-155-157-169-175- 062140- OH . OHIO COUNTIES INCLUDED ARE ASHLAND ASHTABULA BELMONT CARROLL COLUMBIANA COSHOCTON CRAWFORD CUYAHOGA ERIE GEAUGA GUERNSEY HANCOCK HARRISON HOLMES HURON JEFFERSON KNOX LAKE LORAIN MAHONING MARION MEDINA MORROW PORTAGE RICHLAND STARK SUMMIT TRUMBULL TUSCARAWAS WAYNE WYANDOT PAC001-003-005-007-009-013-019-021-023-027-031-033-035-037-039- 041-043-047-051-053-055-057-059-061-063-065-067-071-073-075-081- 085-087-093-097-099-107-109-111-113-119-121-125-129-133- 062140- PA Read more

WW 0606 Status Updates
STATUS REPORT ON WW 606 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BROYLES..08/06/24 ATTN...WFO...OKX...PHI...BGM... STATUS REPORT FOR WS 606 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NJC003-005-007-013-015-017-019-021-023-025-027-029-031-035-037- 039-041-062140- NJ . NEW JERSEY COUNTIES INCLUDED ARE BERGEN BURLINGTON CAMDEN ESSEX GLOUCESTER HUDSON HUNTERDON MERCER MIDDLESEX MONMOUTH MORRIS OCEAN PASSAIC SOMERSET SUSSEX UNION WARREN NYC071-087-062140- NY . NEW YORK COUNTIES INCLUDED ARE ORANGE ROCKLAND PAC011-017-025-029-045-069-077-079-089-091-095-101-103-127-131- 062140- PA Read more

WW 605 SEVERE TSTM OH PA WV LE 061540Z - 062300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 605 NWS Storm Prediction Center Norman OK 1140 AM EDT Tue Aug 6 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Ohio Western and Central Pennsylvania Northern Panhandle of West Virginia Lake Erie * Effective this Tuesday morning and evening from 1140 AM until 700 PM EDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2 inches in diameter possible A tornado or two possible SUMMARY...Multiple rounds of strong to severe thunderstorms are expected to develop and traverse the watch area through the afternoon. Locally damaging wind gusts and some hail are the main concerns. A tornado or two is also possible later this afternoon. The severe thunderstorm watch area is approximately along and 50 statute miles north and south of a line from 20 miles west of Mansfield OH to 45 miles northeast of Harrisburg PA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). 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 603...WW 604... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 28035. ...Hart Read more

WW 606 SEVERE TSTM NJ NY PA CW 061750Z - 070300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 606 NWS Storm Prediction Center Norman OK 150 PM EDT Tue Aug 6 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of New Jersey Southeast New York Eastern Pennsylvania Coastal Waters * Effective this Tuesday afternoon and evening from 150 PM until 1100 PM EDT. * 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 A tornado or two possible SUMMARY...Isolated thunderstorms are beginning to form over eastern Pennsylvania. These storms will affect the watch area during the mid afternoon, while a larger cluster of thunderstorms currently over western Pennsylvania approaches the region by evening. Damaging wind gusts and some hail are possible with both of these storm clusters. The severe thunderstorm watch area is approximately along and 60 statute miles north and south of a line from 40 miles west of Allentown PA to 20 miles east northeast of New York City NY. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). 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 603...WW 604...WW 605... 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 28030. ...Hart Read more

WW 0607 Status Updates
STATUS FOR WATCH 0607 HAS NOT BEEN ISSUED YET Read more

WW 607 TORNADO NC SC CW 062035Z - 070500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 607 NWS Storm Prediction Center Norman OK 435 PM EDT Tue Aug 6 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southeast North Carolina Northeast South Carolina Coastal Waters * Effective this Tuesday afternoon and Wednesday morning from 435 PM until 100 AM EDT. * Primary threats include... A couple tornadoes possible SUMMARY...Thunderstorms will continue to track inland and affect the watch area this evening. Favorable wind shear will maintain a risk of isolated tornadoes at the activity moves ashore. The tornado watch area is approximately along and 30 statute miles either side of a line from 50 miles west southwest of Myrtle Beach SC to 20 miles southeast of New Bern NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). 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...CONTINUE...WW 603...WW 605...WW 606... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 14035. ...Hart Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Tue Aug 06 2024 Valid 062000Z - 071200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OHIO AND NORTHERN PENNSYLVANIA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA...WYOMING AND SOUTH DAKOTA...THE CAROLINAS...AND ARIZONA... ...SUMMARY... Severe thunderstorms capable of damaging winds, hail, and isolated tornadoes will continue across northern Ohio into New Jersey this afternoon and evening. Others areas of concern include much of Montana into western South Dakota, the coastal Carolinas, and across parts of Arizona. ...20z Update... Minimal changes have been made to the current outlook to adjust for ongoing thunderstorms. Multiple rounds of strong to severe storms are ongoing over parts of the Upper OH valley and Great Lakes. Additional development is expected farther west this afternoon and evening with a risk for some upscale growth. The risk for damaging winds and a couple of tornadoes continues. Across the Carolinas, spiral bands associated with TS Debby will continue to mover inland as the central low drifts east/northeast. Minor clearing has been noted in the precip shield allowing for weak heating in between the better defined bands. Occasional stronger convective cells developing over the Atlantic will remain capable of a couple tornadoes as they move inland into relatively strong low-level shear near the NC/SC border. Thunderstorm developing off the higher terrain in central AZ will be capable of gusty winds and small hail as they move west/southwest later this afternoon. The Marginal area was shifted slightly north to better encompass some of the initial storm development. Otherwise the previous forecast areas remain largely unchanged, see the prior discussion for more information. ..Lyons.. 08/06/2024 .PREV DISCUSSION... /ISSUED 1127 AM CDT Tue Aug 06 2024/ ...OH to NJ... Recent water vapor loop shows a well-defined and fast-moving shortwave trough over Lower MI. This feature will track eastward across parts of OH/PA/NY today, along a corridor of strong heating/destabilization. This will lead to multiple clusters of intense convection capable of damaging winds, large hail. Winds aloft are seasonably strong, but low-level winds are relatively weak. Some increase in low-level winds/shear may occur later today, posing some risk of isolated tornadoes as well. ...MT/WY/SD... Multiple minor shortwave troughs will rotate through the top of the ridge over MT/WY today, while mid-level winds strengthen. A plume of mid-level moisture/lift ahead of these features will lead to scattered thunderstorms over the mountains of western MT by mid afternoon. This activity will spread into the adjacent Plains and intensify. Forecast soundings show sufficient deep-layer shear to support supercell storm structures capable of large hail and damaging wind gusts through the afternoon and evening. ...AZ... A weak upper low is present this morning over northern Mexico tracking slowly westward. Enhanced easterly mid level winds around the northern periphery of the low are spreading westward across AZ today. A few clusters of thunderstorms are likely to form over the mountains of eastern AZ and propagate westward through the evening into the lower deserts. This pattern appears favorable for a more organized damaging wind event across parts of AZ, although the details of thunderstorm coverage/intensity over the higher terrain of eastern AZ will help dictate the overall threat later today. ...Carolinas... TS Debby remains over southeast GA, with bands of offshore thunderstorms tracking inland along the coasts of SC/southeast NC. Sufficient low-level shear will remain in place through the afternoon and evening for a risk of transient mesocyclones and a few tornadoes through the forecast period. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Tue Aug 06 2024 Valid 062000Z - 071200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OHIO AND NORTHERN PENNSYLVANIA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA...WYOMING AND SOUTH DAKOTA...THE CAROLINAS...AND ARIZONA... ...SUMMARY... Severe thunderstorms capable of damaging winds, hail, and isolated tornadoes will continue across northern Ohio into New Jersey this afternoon and evening. Others areas of concern include much of Montana into western South Dakota, the coastal Carolinas, and across parts of Arizona. ...20z Update... Minimal changes have been made to the current outlook to adjust for ongoing thunderstorms. Multiple rounds of strong to severe storms are ongoing over parts of the Upper OH valley and Great Lakes. Additional development is expected farther west this afternoon and evening with a risk for some upscale growth. The risk for damaging winds and a couple of tornadoes continues. Across the Carolinas, spiral bands associated with TS Debby will continue to mover inland as the central low drifts east/northeast. Minor clearing has been noted in the precip shield allowing for weak heating in between the better defined bands. Occasional stronger convective cells developing over the Atlantic will remain capable of a couple tornadoes as they move inland into relatively strong low-level shear near the NC/SC border. Thunderstorm developing off the higher terrain in central AZ will be capable of gusty winds and small hail as they move west/southwest later this afternoon. The Marginal area was shifted slightly north to better encompass some of the initial storm development. Otherwise the previous forecast areas remain largely unchanged, see the prior discussion for more information. ..Lyons.. 08/06/2024 .PREV DISCUSSION... /ISSUED 1127 AM CDT Tue Aug 06 2024/ ...OH to NJ... Recent water vapor loop shows a well-defined and fast-moving shortwave trough over Lower MI. This feature will track eastward across parts of OH/PA/NY today, along a corridor of strong heating/destabilization. This will lead to multiple clusters of intense convection capable of damaging winds, large hail. Winds aloft are seasonably strong, but low-level winds are relatively weak. Some increase in low-level winds/shear may occur later today, posing some risk of isolated tornadoes as well. ...MT/WY/SD... Multiple minor shortwave troughs will rotate through the top of the ridge over MT/WY today, while mid-level winds strengthen. A plume of mid-level moisture/lift ahead of these features will lead to scattered thunderstorms over the mountains of western MT by mid afternoon. This activity will spread into the adjacent Plains and intensify. Forecast soundings show sufficient deep-layer shear to support supercell storm structures capable of large hail and damaging wind gusts through the afternoon and evening. ...AZ... A weak upper low is present this morning over northern Mexico tracking slowly westward. Enhanced easterly mid level winds around the northern periphery of the low are spreading westward across AZ today. A few clusters of thunderstorms are likely to form over the mountains of eastern AZ and propagate westward through the evening into the lower deserts. This pattern appears favorable for a more organized damaging wind event across parts of AZ, although the details of thunderstorm coverage/intensity over the higher terrain of eastern AZ will help dictate the overall threat later today. ...Carolinas... TS Debby remains over southeast GA, with bands of offshore thunderstorms tracking inland along the coasts of SC/southeast NC. Sufficient low-level shear will remain in place through the afternoon and evening for a risk of transient mesocyclones and a few tornadoes through the forecast period. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Tue Aug 06 2024 Valid 071200Z - 081200Z Due to an increase in expected coverage of high-based convection tomorrow afternoon, the Isolated Dry Thunder area has been expanded over portions of the Great Basin. Otherwise, see the previous discussion for further details. ..Supinie.. 08/06/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Tue Aug 06 2024/ ...Synopsis... ...Isolated Dry Thunderstorms... Isolated dry thunderstorms will continue across portions of southern Utah, northwestern Colorado, and south-central Wyoming. A plume of mainly mid-level moisture, with precipitable water values around 0.50-0.75, will support high-based convection with little measurable rainfall, amid receptive fuels. Gusty and erratic outflow winds will be possible near thunderstorms. ...Wind/Dry... Enhanced mid-level westerly flow will remain over the Snake River Plain on Wednesday. Deeply mixed profiles will support downward mixing of flow aloft and sustained surface winds 15-20 mph. This will overlap with relative humidity reductions to 10-15 percent and receptive fuels supporting inclusion of an Elevated risk area. ...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 0256 PM CDT Tue Aug 06 2024 Valid 071200Z - 081200Z Due to an increase in expected coverage of high-based convection tomorrow afternoon, the Isolated Dry Thunder area has been expanded over portions of the Great Basin. Otherwise, see the previous discussion for further details. ..Supinie.. 08/06/2024 .PREV DISCUSSION... /ISSUED 0154 AM CDT Tue Aug 06 2024/ ...Synopsis... ...Isolated Dry Thunderstorms... Isolated dry thunderstorms will continue across portions of southern Utah, northwestern Colorado, and south-central Wyoming. A plume of mainly mid-level moisture, with precipitable water values around 0.50-0.75, will support high-based convection with little measurable rainfall, amid receptive fuels. Gusty and erratic outflow winds will be possible near thunderstorms. ...Wind/Dry... Enhanced mid-level westerly flow will remain over the Snake River Plain on Wednesday. Deeply mixed profiles will support downward mixing of flow aloft and sustained surface winds 15-20 mph. This will overlap with relative humidity reductions to 10-15 percent and receptive fuels supporting inclusion of an Elevated risk area. ...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 1215 PM CDT Tue Aug 06 2024 Valid 071200Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER THE COASTAL CAROLINAS...AND OVER PARTS OF THE CENTRAL TO NORTHERN PLAINS... ...SUMMARY... Scattered strong storms will be possible from eastern Wyoming and Colorado into parts of the central Plains late Wednesday afternoon and evening, with more isolated activity into the northern Plains. A few strong thunderstorms in association with Tropical Storm Debby may impact parts of the coastal Carolinas Wednesday. ...Synopsis... Moderate west/northwest winds aloft will extend from the northern Rockies across the northern Plains and upper MS Valley on Wednesday as an upper rough over SK/MB drops southward toward the US/CN border into Thursday morning. Through 00Z, the strongest cooling aloft will extend into MT and ND, with 40+ kt 500 mb winds as far south as northern NE and IA. At the surface, low pressure will generally stretch from the ND/MN border into central NE and toward eastern CO/western KS through late afternoon, with a surface high from the upper Great Lakes to the lower MO Valley limiting moisture return. However, a narrow plume of 60s F dewpoints should develop ahead of the front across KS, NE, and the Dakotas, aiding destabilization. Meanwhile, Tropical Storm Debby is forecast to linger near the SC Coast, with persistent heavy rain threat along with a low-end risk of a tornado as low-level shear remains favorable. ...Central and northern Plains... Strong heating will yield steep low-level lapse rates along the Front Range and extending east/northeast ahead of the cold front into western NE and nosing into SD. This will result in an unstable and uncapped air mass near the front, where convergence will support storms forming after 20Z from southeast WY into north-central CO, and toward 00Z into SD. The high-based activity over WY and CO will favor locally strong wind gusts, and these storms may persist through the evening into across southern NE and northern KS with wind potential. Farther north, deep-layer shear will may favor isolated cells capable of marginal hail, but midlevel lapse rates look to be poor. ...Coastal Carolinas... Per NHC guidance, Tropical Storm Debby is forecast to be just off the SC Coast for much of the day, moving onshore early Thursday. Dewpoints over the coastal counties north and east of the center of circulation are forecast to remain in the upper 70s F, which may yield sufficient instability for embedded severe cells within banded convection. As such, will maintain low tornado probabilities for any stronger embedded cells. ..Jewell.. 08/06/2024 Read more

MD 1843 CONCERNING TORNADO WATCH 603... FOR PORTIONS OF NORTHEAST SOUTH CAROLINA INTO SOUTHERN NORTH CAROLINA
Mesoscale Discussion 1843 NWS Storm Prediction Center Norman OK 1040 AM CDT Tue Aug 06 2024 Areas affected...portions of northeast South Carolina into southern North Carolina Concerning...Tornado Watch 603... Valid 061540Z - 061745Z The severe weather threat for Tornado Watch 603 continues. SUMMARY...An isolated tornado threat continues across portions of the coastal Carolinas in association with Tropical Storm Debbie. A few brief tornadoes may accompany the stronger storms through at least early afternoon. DISCUSSION...Multiple bands of stronger showers and thunderstorms are impinging on the counties in northern SC into southern NC that border the Atlantic in advance of the center of TS Debbie, which continues to gradually drift north-northeastward this morning. Given poor tropospheric lapse rates and widespread, persistent cloud cover, overall buoyancy should remain modest (i.e. 500-1000 J/kg MLCAPE, supported mainly by mid to upper 70s F surface dewpoints). Around 200-300 m2/s2 of effective SRH may overspread the 80+ F surface temperatures along coastal NC later this afternoon, where a slight uptick in tornado potential may be realized. Otherwise, a persistent threat of a stray, brief tornado should persist while gradually shifting northward along the NC Outer Banks through the day. ..Squitieri.. 08/06/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MHX...RAH...ILM...CHS... LAT...LON 34857747 34557724 33967770 33667801 32627958 32498000 33637988 34357926 34897855 34947783 34857747 Read more

MD 1844 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR PORTIONS OF EASTERN PENNSYLVANIA...NEW JERSEY...FAR EASTERN MARYLAND...NORTHERN DELAWARE
Mesoscale Discussion 1844 NWS Storm Prediction Center Norman OK 1206 PM CDT Tue Aug 06 2024 Areas affected...Portions of eastern Pennsylvania...New Jersey...far eastern Maryland...northern Delaware Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 061706Z - 061830Z Probability of Watch Issuance...80 percent SUMMARY...The severe threat should increase through the afternoon, with multiple rounds of strong to severe thunderstorms expected. Damaging gusts are the main threat, though a couple instances of large hail or a tornado are also possible. A Severe Thunderstorm Watch issuance will eventually be needed. DISCUSSION...Multiple semi-discrete, robust updrafts (including supercells) have become established over western PA and are poised to track eastward through the afternoon. However, before these storms cross the Appalachians, at least scattered thunderstorms are expected to develop east of the Appalachians amid a destabilizing airmass. Visible satellite shows a rapidly expanding CU field, with MRMS mosaic radar data showing convective initiation potentially already underway. To the lee of the Appalachians, surface temperatures are already reaching 90 F amid 70+ F dewpoints, supporting 8 C/km boundary-layer lapse rates (per 16Z mesoanalysis). Though deep-layer shear should remain modest through at least early to mid afternoon (i.e. around 30 kts effective bulk shear), the steepening low-level lapse rates will support a damaging gust threat. Later this afternoon, as the stronger storms to the west approach the region, an instance or two of large hail and maybe even a tornado could occur as these storms traverse a baroclinic boundary, where low-level shear may be locally maximized. A Severe Thunderstorm Watch will be needed soon to address the impending severe threat. ..Squitieri/Hart.. 08/06/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OKX...PHI...BGM...CTP...LWX... LAT...LON 41547634 41337471 41107410 40487393 39777413 39157450 39087501 39117540 39457603 40057578 40817586 41547634 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1157 AM CDT Tue Aug 06 2024 Valid 061700Z - 071200Z The previous Isolated Dry Thunder area has been tweaked to reflect the latest thinking on convective coverage this afternoon, and the Elevated risk area has been expanded slightly to account for observed trends this morning. Otherwise, see the previous discussion for more details. ..Supinie.. 08/06/2024 .PREV DISCUSSION... /ISSUED 0124 AM CDT Tue Aug 06 2024/ ...Synopsis... ...Isolated Dry Thunderstorms... A shortwave trough will bring forcing for ascent into the northern and central Rockies today. Mid-level moisture above drier boundary-layer conditions will favor dry thunderstorm chances, with little wetting rainfall expected. Fuels from southwestern MT, southeastward into WY, eastern UT, and northwestern CO are sufficiently dry for new lightning ignitions. In addition, gusty and erratic outflow winds will be possible with any stronger storms that develop. ...Elevated Fire Weather, Snake River Plain Idaho... As the shortwave advances across the northern/central Rockies, a band of enhanced mid-level westerly flow will overspread portions of Idaho and Montana this afternoon. An increase in winds is expected across the Snake River Plain, where relative-humidity reductions to 10-15 percent will overlap sustained winds 15-20 mph. Occasional localized critical conditions may be possible. Overall, this looks to be too localized to include an area with this outlook. ...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 1157 AM CDT Tue Aug 06 2024 Valid 061700Z - 071200Z The previous Isolated Dry Thunder area has been tweaked to reflect the latest thinking on convective coverage this afternoon, and the Elevated risk area has been expanded slightly to account for observed trends this morning. Otherwise, see the previous discussion for more details. ..Supinie.. 08/06/2024 .PREV DISCUSSION... /ISSUED 0124 AM CDT Tue Aug 06 2024/ ...Synopsis... ...Isolated Dry Thunderstorms... A shortwave trough will bring forcing for ascent into the northern and central Rockies today. Mid-level moisture above drier boundary-layer conditions will favor dry thunderstorm chances, with little wetting rainfall expected. Fuels from southwestern MT, southeastward into WY, eastern UT, and northwestern CO are sufficiently dry for new lightning ignitions. In addition, gusty and erratic outflow winds will be possible with any stronger storms that develop. ...Elevated Fire Weather, Snake River Plain Idaho... As the shortwave advances across the northern/central Rockies, a band of enhanced mid-level westerly flow will overspread portions of Idaho and Montana this afternoon. An increase in winds is expected across the Snake River Plain, where relative-humidity reductions to 10-15 percent will overlap sustained winds 15-20 mph. Occasional localized critical conditions may be possible. Overall, this looks to be too localized to include an area with this outlook. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1127 AM CDT Tue Aug 06 2024 Valid 061630Z - 071200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING FROM EASTERN OHIO ACROSS MUCH OF PENNSYLVANIA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER MUCH OF MONTANA INTO WESTERN SOUTH DAKOTA...THE COASTAL CAROLINAS...AND ACROSS PARTS OF ARIZONA... ...SUMMARY... Severe thunderstorms capable of damaging winds, hail, and isolated tornadoes will affect areas from northern Ohio into New Jersey today. Others areas of concerns include much of Montana into western South Dakota, the coastal Carolinas, and across parts of Arizona. ...OH to NJ... Recent water vapor loop shows a well-defined and fast-moving shortwave trough over Lower MI. This feature will track eastward across parts of OH/PA/NY today, along a corridor of strong heating/destabilization. This will lead to multiple clusters of intense convection capable of damaging winds, large hail. Winds aloft are seasonably strong, but low-level winds are relatively weak. Some increase in low-level winds/shear may occur later today, posing some risk of isolated tornadoes as well. ...MT/WY/SD... Multiple minor shortwave troughs will rotate through the top of the ridge over MT/WY today, while mid-level winds strengthen. A plume of mid-level moisture/lift ahead of these features will lead to scattered thunderstorms over the mountains of western MT by mid afternoon. This activity will spread into the adjacent Plains and intensify. Forecast soundings show sufficient deep-layer shear to support supercell storm structures capable of large hail and damaging wind gusts through the afternoon and evening. ...AZ... A weak upper low is present this morning over northern Mexico tracking slowly westward. Enhanced easterly mid level winds around the northern periphery of the low are spreading westward across AZ today. A few clusters of thunderstorms are likely to form over the mountains of eastern AZ and propagate westward through the evening into the lower deserts. This pattern appears favorable for a more organized damaging wind event across parts of AZ, although the details of thunderstorm coverage/intensity over the higher terrain of eastern AZ will help dictate the overall threat later today. ...Carolinas... TS Debby remains over southeast GA, with bands of offshore thunderstorms tracking inland along the coasts of SC/southeast NC. Sufficient low-level shear will remain in place through the afternoon and evening for a risk of transient mesocyclones and a few tornadoes through the forecast period. ..Hart/Halbert/Lyons.. 08/06/2024 Read more