No Mesoscale Discussions are in effect as of Mon Aug 5 14:20:22 UTC 2024.

WW 0596 Status Updates
STATUS REPORT ON WW 596 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..BENTLEY..08/05/24 ATTN...WFO...JAX...TBW...MLB...CHS... STATUS REPORT FOR WT 596 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC001-003-007-017-019-023-031-035-041-049-053-057-069-075-081- 083-089-095-097-101-103-105-107-109-115-117-119-125-127- 051540- FL . FLORIDA COUNTIES INCLUDED ARE ALACHUA BAKER BRADFORD CITRUS CLAY COLUMBIA DUVAL FLAGLER GILCHRIST HARDEE HERNANDO HILLSBOROUGH LAKE LEVY MANATEE MARION NASSAU ORANGE OSCEOLA PASCO PINELLAS POLK PUTNAM ST. JOHNS SARASOTA SEMINOLE SUMTER UNION VOLUSIA GAC025-029-039-049-051-109-127-179-183-191-229-267-299-305- 051540- GA . GEORGIA COUNTIES INCLUDED ARE BRANTLEY BRYAN CAMDEN Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 AM CDT Mon Aug 05 2024 Valid 051300Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER OHIO VALLEY INTO NEW ENGLAND...ACROSS PORTIONS OF THE UPPER MIDWEST...AND FROM NORTHERN FLORIDA INTO SOUTHERN GEORGIA AND SOUTHEAST SOUTH CAROLINA... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... With height falls well underway on its northern rim -- over the northern Rockies -- the Four Corners regional anticyclone has become ore zonally elongated, with a shift/reformation of the associated 500-mb high over the San Juan Mountains or adjoining San Luis Valley. Through the period, associated ridging will extend east-southeastward across southern KS to AR, west-southwestward over the LAS area to southern CA, and will rebuild northwestward over the northern Rockies. The latter will occur as a series of closely spaced shortwave perturbations -- apparent in moisture-channel imagery from the western Dakotas to north-central MT -- shift eastward across the Dakotas to MN by 00Z. These features then should cross WI and Lake Michigan tonight. Just west of the ridge, a weak shortwave trough now over the central/northern Sierra should move north-northeastward toward the northern Rockies through the day. Farther east, a strong shortwave trough was evident over northern ON north of Lake Superior, in the southwest quadrant of a vast cyclone covering most of eastern Canada. This trough should move east-southeastward across southernmost QC to ME by 06Z, then over the Canadian Maritimes. At the surface, 11Z analysis showed a wavy, slow-moving (mostly stationary) frontal zone from central New England to a weak low over southern Lake Huron, across southern Lake Michigan and northern IA, to another low over south-central SD between PIR-VTN, then across central WY. As the mid/upper shortwave trough approaches and grazes the area, the eastern part of the front should move slowly southeastward across the Lower Great Lakes, Adirondacks, White Mountains and much of ME by 00Z. The trailing part should drift southward into northern parts of OH/IN/IL, then decelerate/stall overnight. The SD low should ripple east-southeastward along the front and across the Siouxland region by 00Z, then over northern IA tonight. The trailing cold front from there should extend across eastern NE, northwestern KS and southeastern CO by 00Z, stalling overnight over southwestern KS and southeastern CO in response to cyclogenesis near LAA. ...FL/GA/SC -- Hurricane Debby... Hurricane Debby has made landfall in the FL "Big Bend" coastal area, and the center is forecast by NHC to proceed slowly northeastward over the FL/GA line through the period. See SPC Tornado Watch 596 and related mesoscale discussions for near-term potential. Refer to latest NHC advisories for forecast track/intensity of Debby, and tropical watches/warnings. The existing tornado potential southeast of center largely is expected to translate along with Debby, while expanding northeastward to the Atlantic Coast of northeastern FL and GA, as favorable low-level theta-e advection from the Atlantic destabilizes the nearshore airmass there. An extensive area of precip northeast through north of center should be maintained, substantially restricting instability over northwestern FL and southwestern/ south-central GA to the left of the forecast center track, and reinforcing the baroclinic gradient there. That should act as a buoyancy-limiting northwestern bound to the supercell/tornado threat. Meanwhile, as low-level flow veers further on the FL West Coast through the remainder of this morning, and weaker lift with a more skeletal convective structure moves across the area south of center, supercell/tornado potential will diminish there. The optimal CAPE/shear parameter space should shift through northern FL into southeastern GA today, while expanding along the GA and eventually SC Coast later today through tonight. ...Northeast and Great Lakes to upper Mississippi Valley... Through tonight, multiple rounds of strong to severe convection are possible across this lengthy but relatively narrow corridor near the front, through tonight. Damaging winds will be the main concern in the Northeast, though enough low-level shear/hodograph enlargement exists in forecast soundings across parts of northern New England to support some supercell potential. Meanwhile, supercells with large hail and a tornado threat may develop before dark or in early evening between southern MN and southern Lake Michigan. Activity overall should evolve upscale to a more clustered, wind-driven threat with time, lasting later in the evening over western areas. Surface-based development is likely to occur earlier in the eastern "slight risk" area -- from midday through this afternoon, as peripheral mass response to the Canadian perturbation increases low-level convergence and tightens the height gradient aloft. The latter will increase deep shear, though nearly unidirectional wind profiles should persist over the corridor, except in parts of north-central New England and northern IA/southern MN, each to the east of frontal-wave lows. Strong diurnal warming will occur in conjunction with favorable low-level moisture, with surface dewpoints commonly in the mid/upper 60s from OH eastward and low 70s from northern IN across the upper Mississippi Valley. This should yield peak/preconvective MLCAPE ranging from around 500-1500 J/kg over the Northeast -- where midlevel lapse rates will be weaker -- to 2000-3000 J/kg in a narrow corridor near the front from northern OH to the IA/MN border vicinity. However, capping will be stronger over the IA/MN/WI part of the front, and diurnal development/ coverage accessing the greatest surface-based buoyancy is more uncertain than evening/overnight severe hail/gust potential near and north of the front. ...Northern Rockies and vicinity... Isolated to scattered thunderstorms are expected to develop this afternoon and evening over much of ID into western MT, as modest large-scale ascent preceding the shortwave trough spreads across diurnally heated higher elevations. Development will be supported further by at least marginally favorable moisture, represented by lower-elevation surface dewpoints now in the upper 40s to low 60s F, and not expected to dry very much via mixing through early/mid afternoon. Still, heating/mixing should be strong enough to build steep low/middle-level lapse rates and "inverted-v" thermodynamic profiles supporting strong/isolated severe gusts, Some of this activity also may take the form of dry thunderstorms, especially in eastern areas -- see SPC Fire Weather products for more on that concern. ..Edwards/Grams.. 08/05/2024 Read more

MD 1822 CONCERNING TORNADO WATCH 596... FOR COASTAL GA VICINITY
Mesoscale Discussion 1822 NWS Storm Prediction Center Norman OK 0613 AM CDT Mon Aug 05 2024 Areas affected...coastal GA vicinity Concerning...Tornado Watch 596... Valid 051113Z - 051315Z The severe weather threat for Tornado Watch 596 continues. SUMMARY...Potential for a few waterspouts and brief/weak tornadoes should be focused along the coastal Georgia vicinity through late morning. DISCUSSION...Convection has blossomed over the past couple hours off the GA and FL Atlantic coast. Some of this activity has been drawn northwestward, as an outer band structure downstream of TC Debby. The most persistent near-term band will probably remain just north of the coastal GA-FL border, with weak, transient circulations ongoing from southern Camden County, GA offshore. Additional banding within lower-topped convection may also occur farther north towards the coastal GA-SC border through the rest of the morning. While the degree of instability is weak, but likely improved slightly from the 06Z JAX/CHS soundings, the presence of a couple-county wide ribbon of upper 70s surface dew points across coastal southeast GA will contribute to regenerative updrafts over the next few hours. Enhanced low-level hodograph curvature within the northeast quadrant of slow-moving Debby will favor threats for offshore waterspouts and perhaps a few brief tornadoes this morning. ..Grams.. 08/05/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CHS...JAX... LAT...LON 30738112 30618149 30788194 31188191 31668182 32008152 32168125 31928043 31028098 30738112 Read more

WW 0596 Status Updates
STATUS FOR WATCH 0596 HAS NOT BEEN ISSUED YET Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0353 AM CDT Mon Aug 05 2024 Valid 081200Z - 131200Z ...DISCUSSION... Latest (05/00z) ECENS/GEFS output suggests than an initially prominent mid-level ridge over the Canadian Northwest Territories will gradually become suppressed, with the center of higher heights shifting east-southeastward toward northern Manitoba through early this weekend. Preceding this feature, it appears that a significant positively tilted trough will pivot through northwestern Ontario and the upper Great Lakes, before digging through the lower Great Lakes and upper Ohio Valley vicinity. As this occurs, it appears that Debby's remnant lower/mid-level circulation will finally accelerate northeastward out of the Southeast, and offshore of the Mid Atlantic coast by next weekend. While it might not be out of the question that this could occur in a manner supportive of an appreciable increase in potential for convection capable of producing tornadoes across parts of the Carolinas, Virginia and Delmarva Peninsula vicinity, probabilities for this still seem generally low at this time. Otherwise, modest westerly to northwesterly mid/upper flow developing across the northern Rockies into northern and central U.S. Great Plains, around the periphery of a prominent ridge shifting from the Four Corners into southern Great Plains, may be conditionally supportive of organized convective development through much of the period. However, guidance continues to generally indicate that seasonably modest destabilization will tend to limit the severe weather potential. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 AM CDT Mon Aug 05 2024 Valid 071200Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT ACROSS PARTS OF COASTAL NORTH AND SOUTH CAROLINA...PARTS OF WESTERN NORTH AND SOUTH DAKOTA...EASTERN WYOMING...NORTHEASTERN COLORADO AND WESTERN NEBRASKA... ...SUMMARY... A few strong thunderstorms may impact parts of the coastal Carolinas and northern Great Plains Wednesday into Wednesday night, and perhaps pose some risk for severe weather. ...Synopsis... It appears that a prominent mid-level ridge will be maintained across the Canadian Northwest Territories into and through this period. To its south, mid-level troughing across the Canadian Prairies through the adjacent international border area may elongate westward across the British Columbia coast. To the east, as one short wave impulse accelerates east of the St. Lawrence Valley through the Canadian Maritimes, another significant short wave trough is forecast to dig across the southeastern Hudson/James Bay vicinity, reinforcing large-scale positively tilted troughing across much of the eastern Canadian provinces and northern New England. In the southern mid- and subtropical latitudes, it appears that one prominent mid-level ridge will be maintained across the southern Great Basin into southern Great Plains. Another ridge over the western subtropical Atlantic may build westward toward the southern Mid Atlantic coast. As this occurs, the initially quasi-stationary to very slow moving offshore circulation center, of what is still forecast to be Tropical Storm Debby, may slowly accelerate northward toward the South Carolina coast Wednesday night. ...Carolinas/Southeastern Georgia... Sizable spread exists among the model output concerning the track of Debby. Even based on the official forecast track, the risk for tornadoes remains unclear, particularly inland of the coast where the boundary layer may remain characterized by weak to negligible buoyancy. ...Northern High Plains... In the presence of steep lapse rates, beneath moderate to strong westerly to northwesterly mid/upper flow (including 30-40 kt around 500 mb), models indicate that mixed-layer CAPE on the order of 1000-2000 J/kg may develop within lee surface troughing. As this supports widely scattered thunderstorm activity by late Wednesday afternoon, isolated supercells might evolve and pose a risk for severe hail and wind into Wednesday evening. ..Kerr.. 08/05/2024 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0222 AM CDT Mon Aug 05 2024 Valid 071200Z - 081200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO WEDNESDAY NIGHT ACROSS PARTS OF COASTAL NORTH AND SOUTH CAROLINA...PARTS OF WESTERN NORTH AND SOUTH DAKOTA...EASTERN WYOMING...NORTHEASTERN COLORADO AND WESTERN NEBRASKA... ...SUMMARY... A few strong thunderstorms may impact parts of the coastal Carolinas and northern Great Plains Wednesday into Wednesday night, and perhaps pose some risk for severe weather. ...Synopsis... It appears that a prominent mid-level ridge will be maintained across the Canadian Northwest Territories into and through this period. To its south, mid-level troughing across the Canadian Prairies through the adjacent international border area may elongate westward across the British Columbia coast. To the east, as one short wave impulse accelerates east of the St. Lawrence Valley through the Canadian Maritimes, another significant short wave trough is forecast to dig across the southeastern Hudson/James Bay vicinity, reinforcing large-scale positively tilted troughing across much of the eastern Canadian provinces and northern New England. In the southern mid- and subtropical latitudes, it appears that one prominent mid-level ridge will be maintained across the southern Great Basin into southern Great Plains. Another ridge over the western subtropical Atlantic may build westward toward the southern Mid Atlantic coast. As this occurs, the initially quasi-stationary to very slow moving offshore circulation center, of what is still forecast to be Tropical Storm Debby, may slowly accelerate northward toward the South Carolina coast Wednesday night. ...Carolinas/Southeastern Georgia... Sizable spread exists among the model output concerning the track of Debby. Even based on the official forecast track, the risk for tornadoes remains unclear, particularly inland of the coast where the boundary layer may remain characterized by weak to negligible buoyancy. ...Northern High Plains... In the presence of steep lapse rates, beneath moderate to strong westerly to northwesterly mid/upper flow (including 30-40 kt around 500 mb), models indicate that mixed-layer CAPE on the order of 1000-2000 J/kg may develop within lee surface troughing. As this supports widely scattered thunderstorm activity by late Wednesday afternoon, isolated supercells might evolve and pose a risk for severe hail and wind into Wednesday evening. ..Kerr.. 08/05/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0201 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...Synopsis... ...Isolated Dry Thunderstorms... Increasing mid-level ascent associated with a shortwave trough will impact the northern and central Rockies on Tuesday. Mainly mid-level moisture above drier boundary layer conditions will support 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. 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. ..Thornton.. 08/05/2024 ...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 0201 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...Synopsis... ...Isolated Dry Thunderstorms... Increasing mid-level ascent associated with a shortwave trough will impact the northern and central Rockies on Tuesday. Mainly mid-level moisture above drier boundary layer conditions will support 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. 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. ..Thornton.. 08/05/2024 ...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 0159 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...Synopsis... A shortwave disturbance moving across the northern periphery of the western US ridge will be the focus for thunderstorms across northern Great Basin into the Northern Rockies this afternoon, where a plume of mid-level moisture resides. Dry fuels within these regions will support potential for new ignitions. Gusty and erratic outflow will also be possible. Portions of western Montana/Idaho Panhandle may receive wetting rainfall on D1 Sunday. This area may need to be adjusted in coming outlooks based on status of fuels. ..Thornton.. 08/05/2024 ...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 0159 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...Synopsis... A shortwave disturbance moving across the northern periphery of the western US ridge will be the focus for thunderstorms across northern Great Basin into the Northern Rockies this afternoon, where a plume of mid-level moisture resides. Dry fuels within these regions will support potential for new ignitions. Gusty and erratic outflow will also be possible. Portions of western Montana/Idaho Panhandle may receive wetting rainfall on D1 Sunday. This area may need to be adjusted in coming outlooks based on status of fuels. ..Thornton.. 08/05/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0595 Status Updates
STATUS REPORT ON WW 595 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E TLH TO 35 SSE VLD TO 35 W DAB TO 30 ESE AYS. ..GRAMS..08/05/24 ATTN...WFO...JAX...MLB...TBW...TAE... STATUS REPORT FOR WT 595 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC001-017-029-031-035-041-049-053-057-067-069-075-081-083-089- 101-103-105-109-115-119-121-123-127-050740- FL . FLORIDA COUNTIES INCLUDED ARE ALACHUA CITRUS DIXIE DUVAL FLAGLER GILCHRIST HARDEE HERNANDO HILLSBOROUGH LAFAYETTE LAKE LEVY MANATEE MARION NASSAU PASCO PINELLAS POLK ST. JOHNS SARASOTA SUMTER SUWANNEE TAYLOR VOLUSIA GAC039-050740- GA . GEORGIA COUNTIES INCLUDED ARE CAMDEN AMZ450-452-GMZ730-765-830-850-853-050740- Read more

WW 595 TORNADO FL GA CW 042355Z - 051000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 595 NWS Storm Prediction Center Norman OK 755 PM EDT Sun Aug 4 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Central and Northern Florida Southern Georgia Coastal Waters * Effective this Sunday night and Monday morning from 755 PM until 600 AM EDT. * Primary threats include... A few tornadoes possible Isolated damaging wind gusts to 65 mph possible SUMMARY...Convective bands associated with Debby will continue to pose a risk for embedded supercells and a tornado risk. The environment favorable for tornadoes will gradually shift northward this evening into the overnight hours in conjunction with the northward movement of Debby. The tornado watch area is approximately along and 80 statute miles east and west of a line from 35 miles northeast of Valdosta GA to 35 miles southwest of Avon Park FL. 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...CONTINUE...WW 594... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 16030. ...Smith Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1206 AM CDT Mon Aug 05 2024 Valid 061200Z - 071200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE TUESDAY AFTERNOON AND EVENING ACROSS PARTS OF CENTRAL INTO SOUTHEAST MONTANA... ...SUMMARY... Strong storms posing at least some risk for severe weather may impact coastal Georgia and South Carolina, a corridor across the Ohio Valley into northern Mid Atlantic, parts of the northern Rockies into adjacent Great Plains, and southern Arizona Tuesday into Tuesday evening. ...Synopsis... As northwestern Canadian mid-level ridging elongates eastward, evolving positively tilted troughing to its south is forecast to dig toward the western and central Canadian/U.S. border through this period. This may begin to suppress an initially expansive ridge in the lower latitudes of the western and central U.S., including a gradual transition of flow from broadly anticyclonic to cyclonic across the northern Rockies into northern Great Plains late Tuesday through Tuesday night. Downstream, a persistent slow moving mid-level low, initially over northern Quebec, is forecast to redevelop eastward offshore, to the south of Greenland, where significant surface cyclogenesis may take place in response to forcing associated with a vigorous short wave impulse accelerating east of the Canadian Maritimes. However, models indicate that large-scale mid-level troughing will linger across the eastern Canadian provinces and much of the Northeast, reinforced by another perturbation digging southeast of Hudson/James Bays. In response to these developments, an initial surface cold front is forecast to slowly advance southward through the northern Mid Atlantic, south of the southern Great Lakes into the Ohio Valley, and perhaps more rapidly through the lower Missouri Valley and Great Plains. Farther south, between the Southwestern mid-level high and another high over the subtropical western Atlantic, the remnant circulation of what is now Hurricane Debby may only very slowly migrate eastward across southeastern Georgia coastal areas. ...Coastal Georgia/South Carolina... Forcing for ascent, boundary-layer buoyancy and low-level shear may remain conducive to convective development with potential to produce tornadoes into at least early Tuesday. However, this potential will be limited by the slow motion of the lingering tropical cyclone, and may largely become confined offshore of coastal areas later Tuesday/Tuesday night. ...Ohio Valley into Mid Atlantic... Westerly mid-level flow is still generally forecast to begin to weaken Tuesday, and there may be a tendency for the front and/or preceding outflow to advance south of the stronger lingering flow. Peak afternoon boundary-layer instability in a narrow corridor along/ahead of the front may also not be as large as preceding days. However, it might still become sufficient to support scattered organizing thunderstorm activity with potential to produce locally damaging wind gusts Tuesday afternoon and evening. ...Northern Rockies and adjacent Great Plains... Downstream of the approaching mid-level trough, it appears that destabilization across the higher terrain of west central and southern Montana will become supportive of scattered strong thunderstorm development. Low-level moisture may become sufficient to support CAPE on the order of 1000+ J/kg, in the presence of strengthening westerly mid/upper flow (around 40-70+ kt in the 500-300 mb layer). This environment may become conducive to widely scattered supercells with potential to produce severe hail and locally strong wind gusts. It also still appears possible that forcing for ascent, associated with low-level warm advection, could eventually contribute to an upscale growing cluster accompanied by increasing potential for severe surface gusts while spreading into the more strongly heated and deeply mixed lower elevations through Tuesday evening. ...Southern Arizona... Models indicate that a strengthening easterly flow (to 20-30 kts) at mid/upper levels by Tuesday afternoon may aid propagation of developing thunderstorm activity off the higher terrain of southeastern Arizona and adjacent portions of Sonora. A very warm and deeply mixed boundary layer across the lower deserts is forecast to become moderately unstable with CAPE up to around 2000+ J/kg. This will support potential for upscale growth along strengthening convective outflow, accompanied by continuing potential for strong to severe surface gusts into Tuesday evening. ..Kerr.. 08/05/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1232 AM CDT Mon Aug 05 2024 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTHERN FLORIDA...SOUTHEAST GEORGIA AND COASTAL SOUTH CAROLINA...OVER PORTIONS OF THE UPPER MIDWEST...AND FROM THE UPPER OHIO VALLEY INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms are possible today and tonight from the Upper Ohio Valley into New England, across portions of the Upper Midwest, and from northern Florida into southern Georgia and southeast South Carolina. ...Synopsis... Several shortwave impulses/convectively enhanced vorticity maxima will migrate through a broad area of northwesterly upper level flow from the northern Plains to the Great Lakes. Meanwhile, an shortwave trough embedded within the Hudson Bay upper cyclone will pivot east/southeast toward the Northeast. Meanwhile, an upper shortwave trough is forecast to overspread the Pacific Northwest, resulting in enhanced westerly flow across the northern Rockies. Meanwhile, Hurricane Debbie is forecast by the National Hurricane Center to make landfall along the Florida Big Bend and move northeast into southeast GA. Otherwise, an expansive upper anticyclone will overspread much of the Great Basin/Four Corners region into the Lower MS Valley. ...IN/OH/MI into the Northeast... West/southwesterly mid/upper flow will increase through the day as the upper shortwave trough moves east across Ontario and into Quebec. While deep-layer flow will mostly be unidirectional, increasing midlevel flow will support effective shear magnitudes around 35 kt. Midlevel lapse rates will remain poor, but a moist airmass with dewpoints in the mid/upper 60s F will foster MLCAPE values around 1000-2000 J/kg. Furthermore, heating into the mid 80s to low 90s F will steepen low-level lapse rates. Forecast soundings indicate supercell wind profiles, with forecast hodographs becoming elongated/straight above around 2.5 km. This environment should support a mix of supercells and clusters capable of damaging gusts and isolated large hail. Further west across southern Lower MI, northern IN/OH and western PA, stronger instability is forecast. A couple of rounds of thunderstorms will be possible as an initial shortwave moves across the area during the morning. Convection is then expected to form during the afternoon and evening as a surface cold front sags southward across the Great Lakes. While greater instability is forecast, the stronger vertical shear will remain displaced to the northeast across New England. Furthermore, morning convection could be detrimental to afternoon storms depending how prevalent convection is and how much cloud cover lingers over the area. Nevertheless, forecast soundings indicate modestly steep midlevel lapse rates will be present along with modest vertical shear, supporting some risk of strong to severe thunderstorms capable of damaging gusts and perhaps severe hail. ...MN/IA into WI/IL... A surface low is forecast to deepen over the Mid-MO Valley during the afternoon/evening. A warm front will extend east/southeast from the low across northern IA/IL. Thunderstorms are expected to develop in a warm advection regime in the vicinity of the surface warm front. However, it remains uncertain if warm-sector convection will develop, or if convection will mostly be elevated to the cool side of the warm front. Regardless, forecast soundings indicate supercell wind profiles amid a very moist (70s F dewpoints) and unstable airmass. Elevated convection will pose a risk for large hail. If warm midlevel temps/capping can be overcome and storms develop with the warm sector, all severe hazards will be possible, including a couple of tornadoes. Initial cellular convection will likely develop into a more linear, forward-propagating mode during the evening as storms move into southern WI and northern IL. Given uncertainty regarding warm sector development, have maintained probabilities from the previous Day 2 outlook, but upgrades could become necessary if trends toward warm-sector supercell development increase. ...FL/GA/SC... The National Hurricane Center forecast has Hurricane Debbie making landfall along the FL Big Bend vicinity this morning, and becoming centered over southeast GA by Tuesday morning. Within the eastern semicircle of the tropical cyclone across northern FL/southeast GA and coastal SC, low-level SRH will be maximized within an airmass characterized by mid 70s F dewpoints. Tornado potential will accompany any deeper updrafts across this area. ...Northern Rockies... Isolated to scattered thunderstorms are expected to develop during the afternoon/evening as a weak upper shortwave trough impinging on the region brings increasing ascent and midlevel moisture to the region. Steep midlevel lapse rates will support up to around 500 J/kg MLCAPE. Around 25-35 kt effective shear magnitudes will allow for organization of deeper updrafts. Meanwhile, a deeply mixed boundary layer with inverted-v sub-cloud thermodynamic profiles will support strong outflow gusts with this activity. ..Leitman/Thornton.. 08/05/2024 Read more

MD 1820 CONCERNING TORNADO WATCH 595... FOR PARTS OF CENTRAL AND NORTHERN FLORIDA
Mesoscale Discussion 1820 NWS Storm Prediction Center Norman OK 1131 PM CDT Sun Aug 04 2024 Areas affected...parts of central and northern Florida Concerning...Tornado Watch 595... Valid 050431Z - 050630Z The severe weather threat for Tornado Watch 595 continues. SUMMARY...Risk for a couple of tornadoes continues. DISCUSSION...Latest radar loop shows some wobble of the center of Hurricane Debby over the past 1 to 2 hours, though it appears that a gradual northward advance has commenced recently. Otherwise, the strongest convective bands remain centered across west-central Florida, as has been the case for several hours. Little change in the intensity of the bands is noted, though some decrease in the number of rotating cells has occurred. Still, with the low-level wind field more than sufficient to support rotating cells, occasional/brief tornadic spin-ups remain likely over the next several hours. ..Goss.. 08/05/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MLB...TBW...JAX...TAE... LAT...LON 28748378 29368403 30128393 30368236 30108182 29218160 28698149 27648183 27548197 26848248 27478297 28628313 28748378 Read more

WW 0595 Status Updates
STATUS REPORT ON WW 595 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 ENE SGJ TO 30 NW DAB TO 15 SW ORL TO 40 SW AGR. ..GOSS..08/05/24 ATTN...WFO...JAX...MLB...TBW...TAE... STATUS REPORT FOR WT 595 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC001-003-007-017-019-023-029-031-035-041-047-049-053-057-065- 067-069-075-079-081-083-089-101-103-105-107-109-115-119-121-123- 125-127-050540- FL . FLORIDA COUNTIES INCLUDED ARE ALACHUA BAKER BRADFORD CITRUS CLAY COLUMBIA DIXIE DUVAL FLAGLER GILCHRIST HAMILTON HARDEE HERNANDO HILLSBOROUGH JEFFERSON LAFAYETTE LAKE LEVY MADISON MANATEE MARION NASSAU PASCO PINELLAS POLK PUTNAM ST. JOHNS SARASOTA SUMTER SUWANNEE TAYLOR UNION VOLUSIA GAC027-039-049-065-101-173-185-299-050540- GA . GEORGIA COUNTIES INCLUDED ARE Read more

WW 0595 Status Updates
STATUS REPORT ON WW 595 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 N MLB TO 35 SW AGR. ..GOSS..08/05/24 ATTN...WFO...JAX...MLB...TBW...TAE... STATUS REPORT FOR WT 595 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC001-003-007-017-019-023-029-031-035-041-047-049-053-057-065- 067-069-075-079-081-083-089-095-097-101-103-105-107-109-115-117- 119-121-123-125-127-050240- FL . FLORIDA COUNTIES INCLUDED ARE ALACHUA BAKER BRADFORD CITRUS CLAY COLUMBIA DIXIE DUVAL FLAGLER GILCHRIST HAMILTON HARDEE HERNANDO HILLSBOROUGH JEFFERSON LAFAYETTE LAKE LEVY MADISON MANATEE MARION NASSAU ORANGE OSCEOLA PASCO PINELLAS POLK PUTNAM ST. JOHNS SARASOTA SEMINOLE SUMTER SUWANNEE TAYLOR UNION VOLUSIA GAC027-039-049-065-101-173-185-299-050240- GA . GEORGIA COUNTIES INCLUDED ARE Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0745 PM CDT Sun Aug 04 2024 Valid 050100Z - 051200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL AND NORTHERN FLORIDA INTO FAR SOUTHERN GEORGIA... ...SUMMARY... Tropical Storm Debby may produce a few tornadoes over parts of Florida and extreme southern Georgia through early tomorrow morning as it intensifies. Scattered thunderstorms may produce isolated strong wind gusts and hail across parts of southeast Montana, and southern Minnesota/northern Iowa this evening into tonight. ...Northeast... Severe probabilities have been removed from New England as the threat has largely waned. A couple of strong storms may persist in the near-term across parts of VT/NH, but intensity should diminish with southeast extent by 02-03z. ...Southeast Montana Vicinity... The Slight risk has been removed with the 01z update. Convection has struggled to intensify this evening amid meager instability. While instability does increases modestly into far southeast MT, overall severe potential is expected to remain modest and not a widespread as previous expected. Sporadic strong gusts and perhaps marginal hail remain possible with any more intense cells that develop, so the Marginal risk has been maintained. ...Florida... A tornado risk remains across central and northern Florida into extreme GA as bands from TS Debbie continue to move over the area into the morning hours. Debbie has continued to track northward through the day, lessening the threat across the Keys and the southern Peninsula. As such, probabilities have been trimmed from these areas, which are also south of Tornado Watch 595. ...Minnesota/Iowa... Only minor changes have been made to severe probabilities based on latest trends in CAMs guidance. Elevated convection overnight will pose a sporadic risk of large hail and strong gusts. ..Leitman.. 08/05/2024 Read more