SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Fri Aug 30 2024 Valid 310100Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN GREAT LAKES SOUTHWESTWARD INTO THE MID MISSISSIPPI VALLEY... ...SUMMARY... Isolated severe storms, with marginally severe wind gusts and hail will be possible this evening from southeast Lower Michigan southwestward into the mid Mississippi Valley. ...Southern Great Lakes/Mid Mississippi Valley... The latest mosaic water vapor imagery shows an upper-level trough over the western Great Lakes extending southward into the mid Mississippi Valley. An associated cold front is analyzed from southeast Lower Michigan southwestward to near St. Louis, Missouri. Scattered thunderstorms are ongoing along and near the front. Surface dewpoints near and ahead of the front are in the upper 60s and lower 70s F, and the RAP has MLCAPE in the 1200 to 2500 J/k/g range. In addition, regional WSR-88D VWPs near the front have 0-6 km shear ranging from near 20 knot at St. Louis to around 30 knots at Detroit. This environment, combined with steep low-level lapse rates near 7 C/km, should be enough for a marginally severe wind gusts for a couple more hours this evening. Hail could also occur within the cores of the stronger multicells. ..Broyles.. 08/31/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0750 PM CDT Fri Aug 30 2024 Valid 310100Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN GREAT LAKES SOUTHWESTWARD INTO THE MID MISSISSIPPI VALLEY... ...SUMMARY... Isolated severe storms, with marginally severe wind gusts and hail will be possible this evening from southeast Lower Michigan southwestward into the mid Mississippi Valley. ...Southern Great Lakes/Mid Mississippi Valley... The latest mosaic water vapor imagery shows an upper-level trough over the western Great Lakes extending southward into the mid Mississippi Valley. An associated cold front is analyzed from southeast Lower Michigan southwestward to near St. Louis, Missouri. Scattered thunderstorms are ongoing along and near the front. Surface dewpoints near and ahead of the front are in the upper 60s and lower 70s F, and the RAP has MLCAPE in the 1200 to 2500 J/k/g range. In addition, regional WSR-88D VWPs near the front have 0-6 km shear ranging from near 20 knot at St. Louis to around 30 knots at Detroit. This environment, combined with steep low-level lapse rates near 7 C/km, should be enough for a marginally severe wind gusts for a couple more hours this evening. Hail could also occur within the cores of the stronger multicells. ..Broyles.. 08/31/2024 Read more

MD 2038 CONCERNING SEVERE THUNDERSTORM WATCH 665... FOR SOUTHEAST LOWER MICHIGAN
Mesoscale Discussion 2038 NWS Storm Prediction Center Norman OK 0551 PM CDT Fri Aug 30 2024 Areas affected...Southeast lower Michigan Concerning...Severe Thunderstorm Watch 665... Valid 302251Z - 310045Z The severe weather threat for Severe Thunderstorm Watch 665 continues. SUMMARY...The threat for severe wind and hail should persist for the next 2 to 2.5 hours across southeastern Lower Michigan. The greatest severe wind risk may reside along and north of I-65 during this period. DISCUSSION...Convection continues to develop along a cold front across lower MI. Overall intensification has been somewhat gradual, likely owing to somewhat meager large-scale ascent over the region. However, KDTX VWP observations have shown a slight strengthening of mid-level flow over the past 30-60 minutes with 0-6 km bulk shear values increasing closer to 30 knots at times. Additionally, GOES 1-minute imagery shows several strong updraft pulses along the line, indicating that the potential for organized convection persists. Confidence in the coverage of robust convection remains limited given the aforementioned weak forcing for ascent and recent convective trends, but a few severe storms with an attendant hail/severe wind risk remain possible as the cold front continues to push east (especially along and north of I-65 where convection is comparatively more intense based on IR and lightning trends). Latest timing guidance suggests that this activity should exit southeastern lower MI within the next 2-3 hours. ..Moore.. 08/30/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DTX...IWX...GRR... LAT...LON 41898480 42888362 43798304 44058279 44018259 43488235 42998239 42628252 42338274 42068302 41888326 41788357 41738396 41798454 41808474 41898480 Read more

WW 0665 Status Updates
STATUS REPORT ON WW 665 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 ESE SBN TO 15 NNE JXN TO 15 WNW FNT TO 20 WSW OSC. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 2038 ..MOORE..08/30/24 ATTN...WFO...APX...DTX...IWX...GRR... STATUS REPORT FOR WS 665 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MIC023-049-059-063-075-087-091-093-099-115-125-147-151-157-161- 163-302340- MI . MICHIGAN COUNTIES INCLUDED ARE BRANCH GENESEE HILLSDALE HURON JACKSON LAPEER LENAWEE LIVINGSTON MACOMB MONROE OAKLAND ST. CLAIR SANILAC TUSCOLA WASHTENAW WAYNE LCZ422-423-460-LEZ444-LHZ421-422-441-442-443-462-463-464- 302340- CW . ADJACENT COASTAL WATERS INCLUDED ARE ST. CLAIR RIVER Read more

WW 665 SEVERE TSTM MI LE LH 302045Z - 310100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 665 NWS Storm Prediction Center Norman OK 445 PM EDT Fri Aug 30 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Lower Michigan Lake Erie Lake Huron * Effective this Friday afternoon and evening from 445 PM until 900 PM EDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible A tornado or two possible SUMMARY...Thunderstorms are expected to intensify across the watch area through early evening, posing a risk for strong/damaging wind gusts and isolated instances of large hail. A tornado or two will also be possible. The severe thunderstorm watch area is approximately along and 60 statute miles east and west of a line from 30 miles northwest of Bad Axe MI to 20 miles west southwest of Ann Arbor MI. 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. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26025. ...Bunting Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0457 PM CDT Fri Aug 30 2024 Valid 011200Z - 071200Z A midlevel low will move across northern CA/southwest OR and continue east-northeastward across OR into ID D3/Sun through D4/Monday. Ahead of this feature, midlevel moisture will increase, with potential for isolated dry thunderstorms across the Pacific Northwest extending into the Northern Rockies. In addition to thunderstorm chances, a mid-level speed max aloft will bring an increase in surface winds D4/Monday to D5/Tuesday overlapping very dry conditions antecedent conditions across portions of the Great Basin. ...Dry/Windy... Surface winds will increase across northern Nevada into northeastern California and southern Oregon on D4/Monday as a speed max moves through the base of the midlevel low. Sustained west southwesterly winds at 15-20 mph will overlap afternoon relative humidity reductions to 10-15 percent. Fuels within this region are critically dry and support inclusion of 40% Critical probabilities. The best overlap of fuels and windy/dry conditions will be across northwestern Nevada into far northeastern California, where 70% probabilities were included. This area may need to be expanded with subsequent outlooks. Dry and windy conditions will continue eastward into portions of southern Idaho and the Northern Rockies on D5/Tuesday. The highest confidence for potential Critical conditions will be across the Snake River Plain, where a 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Isolated dry thunderstorms will be possible across south/central OR on D3/Sunday, with increasing potential into the overnight hours, as midlevel moisture/instability increases ahead of the midlevel low. A mix of dry/wet thunderstorms will continue spreading/expanding eastward across eastern OR into ID. While fuel receptiveness across the region is uncertain, several days of boundary-layer drying (beneath the large-scale ridge) preceding this thunderstorm event will pose at least some risk of lightning-induced ignitions. Thunderstorm potential will continue across the northern Rockies on Day 5/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk which precluding Isolated Dry Thunderstorm probabilities. ..Thornton.. 08/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0457 PM CDT Fri Aug 30 2024 Valid 011200Z - 071200Z A midlevel low will move across northern CA/southwest OR and continue east-northeastward across OR into ID D3/Sun through D4/Monday. Ahead of this feature, midlevel moisture will increase, with potential for isolated dry thunderstorms across the Pacific Northwest extending into the Northern Rockies. In addition to thunderstorm chances, a mid-level speed max aloft will bring an increase in surface winds D4/Monday to D5/Tuesday overlapping very dry conditions antecedent conditions across portions of the Great Basin. ...Dry/Windy... Surface winds will increase across northern Nevada into northeastern California and southern Oregon on D4/Monday as a speed max moves through the base of the midlevel low. Sustained west southwesterly winds at 15-20 mph will overlap afternoon relative humidity reductions to 10-15 percent. Fuels within this region are critically dry and support inclusion of 40% Critical probabilities. The best overlap of fuels and windy/dry conditions will be across northwestern Nevada into far northeastern California, where 70% probabilities were included. This area may need to be expanded with subsequent outlooks. Dry and windy conditions will continue eastward into portions of southern Idaho and the Northern Rockies on D5/Tuesday. The highest confidence for potential Critical conditions will be across the Snake River Plain, where a 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Isolated dry thunderstorms will be possible across south/central OR on D3/Sunday, with increasing potential into the overnight hours, as midlevel moisture/instability increases ahead of the midlevel low. A mix of dry/wet thunderstorms will continue spreading/expanding eastward across eastern OR into ID. While fuel receptiveness across the region is uncertain, several days of boundary-layer drying (beneath the large-scale ridge) preceding this thunderstorm event will pose at least some risk of lightning-induced ignitions. Thunderstorm potential will continue across the northern Rockies on Day 5/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk which precluding Isolated Dry Thunderstorm probabilities. ..Thornton.. 08/30/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Fri Aug 30 2024 Valid 311200Z - 011200Z Minor adjustments were made to extend isolated dry thunderstorm chances further westward in southern Nevada in agreement with latest guidance. For more information, see the previous discussion below. ..Thornton.. 08/30/2024 .PREV DISCUSSION... /ISSUED 0115 AM CDT Fri Aug 30 2024/ ...Synopsis... Fire weather concerns will remain confined to portions of the Great Basin for Saturday. Upper-level ridging currently over the western CONUS will begin to slowly shift east towards the central Rockies over the next 48-72 hours. As this occurs, a modest plume of monsoonal moisture will spread north/northwest into southeastern NV and southwest UT. Weak mid/upper-level ascent impinging on the fringe of the moisture plume should support isolated thunderstorms by late afternoon. A deep, well-mixed boundary layer will promote limited rainfall with this activity over a region with generally receptive fuels (ERC values at/above the 80th percentile). Consequently, dry lightning will be a fire weather concern. Elsewhere across the West, dry conditions will persist, and increasing mid-level flow along the West Coast may support some breezy conditions in the immediate lee of the central to southern Sierra Nevada. However, confidence in widespread elevated conditions remains too limited for highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0246 PM CDT Fri Aug 30 2024 Valid 302000Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF EASTERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms are possible across eastern Lower Michigan this afternoon, with damaging winds the main threat. Isolated strong to severe thunderstorms may occur into parts of the Midwest, and also across portions of the Carolinas and Virginia into northeast Georgia. ...20z Update... The prior outlook remains valid with only minor modifications. The thunder area over part of the central Plains and Midwest was trimmed behind the advancing cold front. The thunder line was also adjusted eastward over parts of western Lake Michigan. Across parts of the central Mississippi Valley, several multi-cell clusters are ongoing. The environment remains broadly favorable for occasional damaging winds with wet microbursts. The MRGL area was expanded slightly across parts of MO, IL and IN to better account for a few of these clusters as they track eastward. Similarly across parts of the southern Appalachians and western Carolinas, scattered thunderstorms ongoing over the higher terrain of northern GA and western SC, will pose a risk for a few wet microbursts/strong wind gusts through this afternoon. The MRGL area was expanded slightly southwestward to better capture the risk for occasional damaging wind gusts this afternoon. Otherwise the prior outlook remains valid, see the previous discussion. ..Marlow/Lyons.. 08/30/2024 .PREV DISCUSSION... /ISSUED 1124 AM CDT Fri Aug 30 2024/ ...Great Lakes to the Mid Mississippi Valley... Moderate instability is expected to develop ahead of a cold front that should extend from eastern Lower MI southwest into OK this afternoon, with MLCAPE on the order of 2000 J/kg. Modestly enhanced westerly mid-level flow across Lower MI will contribute to 25-35 kts of deep-layer shear, and this should prove sufficient for organized multicell storms. Scattered thunderstorm development is expected this afternoon as weak height falls/ascent overspreads the Slight Risk area, and where somewhat greater storm coverage is expected. Substantial boundary layer heating will result in steep low-level lapse rates, and the strongest storms/clusters will be capable of damaging gusts and isolated severe hail. Farther southwest, mid-level flow will be weaker than across the Great Lakes, but higher MLCAPE and negligible CINH will be present. Scattered thunderstorms should develop along the front after 18-19z, tending to cluster with time, and pose a risk for strong/damaging gusts and perhaps hail. ...Southern Appalachians to the Southern Mid-Atlantic... Diurnal heating of a very moist air mass (mid/upper 70s surface dew points and PW generally above 1.75 inches) will result in strong instability, with pockets of MLCAPE in excess of 3000 J/kg and effectively no CINH. Despite very weak mid-level flow of 10-15 kts, scattered thunderstorms developing near a weak front, and over higher terrain, will pose a risk for a few wet microbursts/strong wind gusts through this afternoon. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Fri Aug 30 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NEW ENGLAND INTO THE CAROLINAS/SOUTHERN APPALACHIANS VICINITY... ...SUMMARY... Strong/isolated severe storms capable of producing gusty/damaging winds will be possible from New England to the Carolinas Sunday. ...Synopsis... A deep upper-level trough will move across parts of eastern Canada into the Northeast and Mid Atlantic on Sunday. Within the larger-scale trough, an intensifying cyclone is forecast to move across Quebec, with a cold front extending southward into New England, and then southwestward across the Northeast, Mid Atlantic, OH/MS Valleys, and southern Plains. Farther west, a mid/upper-level cyclone initially off of the CA coast is forecast to move northeastward and approach the Pacific Northwest coast. ...New England to the Carolinas/southern Appalachians... In advance of the primary cold front, a weakening front and related precipitation will move across parts of New England into the Mid Atlantic from Saturday night into Sunday morning. Destabilization potential in the wake of the morning precipitation and cloudiness remains uncertain. With increasing low/midlevel flow in association with the approaching trough, deep-layer shear will become sufficient for organized convection and at least an isolated damaging-wind threat along/ahead of the approaching front, if sufficient destabilization can occur. Farther south, somewhat stronger destabilization will be possible into the southern Appalachians and Carolinas/Virginia, with scattered storm development expected during the afternoon/evening. Deep-layer flow will be weaker compared to areas to the north, but will still be sufficient for modestly organized storm clusters capable of at least isolated damaging wind during the afternoon and evening. ...Arizona... Sufficient moisture will again support thunderstorm development across terrain-favored areas of Arizona during the afternoon. There may be some potential for stronger outflow to spread into lower elevations within a weak easterly midlevel flow regime, though uncertainty is currently high regarding any more organized severe potential within this regime. ..Dean.. 08/30/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 PM CDT Fri Aug 30 2024 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM NEW ENGLAND INTO THE CAROLINAS/SOUTHERN APPALACHIANS VICINITY... ...SUMMARY... Strong/isolated severe storms capable of producing gusty/damaging winds will be possible from New England to the Carolinas Sunday. ...Synopsis... A deep upper-level trough will move across parts of eastern Canada into the Northeast and Mid Atlantic on Sunday. Within the larger-scale trough, an intensifying cyclone is forecast to move across Quebec, with a cold front extending southward into New England, and then southwestward across the Northeast, Mid Atlantic, OH/MS Valleys, and southern Plains. Farther west, a mid/upper-level cyclone initially off of the CA coast is forecast to move northeastward and approach the Pacific Northwest coast. ...New England to the Carolinas/southern Appalachians... In advance of the primary cold front, a weakening front and related precipitation will move across parts of New England into the Mid Atlantic from Saturday night into Sunday morning. Destabilization potential in the wake of the morning precipitation and cloudiness remains uncertain. With increasing low/midlevel flow in association with the approaching trough, deep-layer shear will become sufficient for organized convection and at least an isolated damaging-wind threat along/ahead of the approaching front, if sufficient destabilization can occur. Farther south, somewhat stronger destabilization will be possible into the southern Appalachians and Carolinas/Virginia, with scattered storm development expected during the afternoon/evening. Deep-layer flow will be weaker compared to areas to the north, but will still be sufficient for modestly organized storm clusters capable of at least isolated damaging wind during the afternoon and evening. ...Arizona... Sufficient moisture will again support thunderstorm development across terrain-favored areas of Arizona during the afternoon. There may be some potential for stronger outflow to spread into lower elevations within a weak easterly midlevel flow regime, though uncertainty is currently high regarding any more organized severe potential within this regime. ..Dean.. 08/30/2024 Read more

No watches are valid as of Fri Aug 30 19:26:02 UTC 2024.

MD 2035 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR MUCH OF CENTRAL NORTH CAROLINA
Mesoscale Discussion 2035 NWS Storm Prediction Center Norman OK 0109 PM CDT Fri Aug 30 2024 Areas affected...much of central North Carolina Concerning...Severe potential...Watch unlikely Valid 301809Z - 302015Z Probability of Watch Issuance...20 percent SUMMARY...Storms will increase in coverage from northern into central North Carolina, with isolated damaging gusts possible. DISCUSSION...Surface analysis and visible imagery show a cold front extending from parts of western VA into northern/northeastern NC. A moist and unstable air mass exists south of this front with MLCAPE over 2000 J/kg, although midlevel lapse rates are poor and below 6.0 C/km. Storms are already forming along the front, as well as north of the wind shift into southern VA. As heating continues, steepening low-level lapse rates along with ample precipitable water will support locally strong downdrafts. Although winds aloft/shear are weak, clustering of storms near the front may result in a few southward-propagating clusters as outflows merge, yielding areas of strong or locally damaging gusts. ..Jewell/Bunting.. 08/30/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...GSP... LAT...LON 35138022 35448072 35808083 36168070 36438023 36537969 36517930 36297882 36117830 36047775 36117699 36267651 36177618 36057602 35547588 35227639 34977666 34867692 34757786 34967950 35138022 Read more

MD 2036 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF EASTERN LOWER MICHIGAN INTO EXTREME NORTHEAST INDIANA AND EXTREME NORTHWEST OHIO
Mesoscale Discussion 2036 NWS Storm Prediction Center Norman OK 0125 PM CDT Fri Aug 30 2024 Areas affected...portions of eastern Lower Michigan into extreme northeast Indiana and extreme northwest Ohio Concerning...Severe potential...Watch possible Valid 301825Z - 302000Z Probability of Watch Issuance...60 percent SUMMARY...The severe threat will increase through the afternoon across portions of eastern Lower Michigan and immediate surrounding areas. Severe gusts are the main concern, though a couple of tornadoes or instances of large hail also cannot be ruled out. A WW issuance may be needed in the next few hours pending favorable convective trends. DISCUSSION...Adequate insolation has supported surface temperatures reaching the mid 80s F amid low 70s F dewpoints, contributing to nearly 3000 J/kg SBCAPE (per 17Z mesoanalysis, and when modifying the 12Z DTX observed sounding). However, both the mesoanalysis and the modified sounding show MLCAPE under 500 J/kg with appreciable MLCINH remaining given some 850 mb dry-air advection from the southwest. Nonetheless, continued diurnal heating and the approach of a 500 mb trough and accompanying surface cold front will support an increase in thunderstorm coverage and intensity into the afternoon. The approach of the upper trough will encourage some strengthening/veering of tropospheric winds, resulting in 30 kts of effective bulk shear and modestly elongated/curved hodographs. Multicells and line segments are the main storm modes expected, though a transient supercell is also possible. Damaging gusts are the main threat, though a couple of tornadoes or instances of severe hail could also occur. Convective trends will continue to be monitored for the need of a WW issuance. ..Squitieri/Bunting.. 08/30/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...DTX...IWX...GRR... LAT...LON 41468590 42578510 43358456 43798388 44058323 43958288 43228237 42698250 41958305 41508333 41328399 41268496 41298539 41468590 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1210 PM CDT Fri Aug 30 2024 Valid 311200Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF CENTRAL APPALACHIANS INTO THE NORTHEAST... ...SUMMARY... Severe thunderstorms capable of producing damaging gusts are possible across portions of the central Appalachians into the Northeast on Saturday. A few strong/severe gusts may also occur over parts of the Ohio/Tennessee Valleys, and across northern Minnesota/Wisconsin into Upper Michigan. ...Synopsis... The large-scale pattern will remain relatively unchanged on Saturday, with a relatively deep upper-level trough extending from eastern Canada into the Northeast/Great Lakes, while an upper-level ridge remains in place over much of the West. A weakening cold front will move into parts of the Northeast and Ohio Valley during the afternoon and evening. A strong reinforcing shortwave trough and attendant cold front will move southeastward across parts of the northern Great Plains into the upper Great Lakes region. ...Parts of the Northeast into the OH/TN Valleys... Scattered thunderstorm development is expected during the afternoon along/ahead of the weakening cold front from parts of the Northeast into the OH/TN Valleys. In general, there will be some displacement between stronger low/midlevel flow to the northeast and stronger instability with southwestward extent. The best relative overlap of instability and modestly favorable flow/shear is expected from the central Appalachians into parts of the Northeast. Multiple loosely organized storm clusters will be possible across this area, with a threat of isolated to scattered damaging winds and localized hail. Deep-layer shear will be weaker into parts of the TN and lower OH Valleys. However, moderate to locally strong buoyancy and relatively large PW will support localized wet microbursts, and perhaps a couple of outflow-driven clusters, with isolated damaging-wind potential. ...Parts of northern MN/WI into upper MI... While buoyancy will likely remain weak due to limited moisture, strong large-scale ascent associated with the approaching shortwave trough will support potential for relatively low-topped convection near the cold front. Steepening low-level lapse rates and strengthening low-level flow will support a threat of at least isolated damaging gusts with the strongest convection. Relatively cold temperatures aloft will also support potential for small to near-severe hail, if deeper convection can develop. ...Arizona... Modestly increasing moisture will support isolated to widely scattered storms across parts of Arizona on Saturday. Initial development is expected over the usual terrain-favored areas. It remains uncertain if storm coverage and intensity will be sufficient for stronger outflow winds to spread into the lower elevations, though this cannot be ruled out within a weak easterly midlevel flow regime. ..Dean.. 08/30/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Fri Aug 30 2024 Valid 301700Z - 311200Z ...NO CRITICAL AREAS... No changes are needed to the D1 Fire Weather Outlook. See previous discussion below for more information. ..Thornton.. 08/30/2024 .PREV DISCUSSION... /ISSUED 1235 AM CDT Fri Aug 30 2024/ ...Synopsis... Fire weather concerns are expected to remain limited for today across the country. Dry conditions will persist across much of the Great Basin and into parts of the Pacific Northwest and central Rockies for this afternoon with RH minimums once again falling into the teens and single digits. Upper-level ridging over the western CONUS will promote mostly clear skies but weak synoptic/gradient winds that should mitigate fire weather concerns. Thunderstorm activity along the lower CO River Valley on Thursday (yesterday) resulted in a mix of wet and dry thunderstorms based on sporadic rainfall measurements and MRMS QPE. A similar mix of wet/dry thunderstorms is expected again today across far southeast NV into western AZ as weak mid-level ascent overspreads the fringe of a modest monsoonal moisture plume. Latest fuel guidance suggests lightning ignition efficiency/fuel dryness gradually increases from far western AZ into southern NV, but the spatial coverage of sufficiently dry fuel with appreciable dry lightning threat appears too limited to introduce highlights. ...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 1124 AM CDT Fri Aug 30 2024 Valid 301630Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF EASTERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms are possible across eastern Lower Michigan this afternoon, with damaging winds the main threat. Isolated strong to severe thunderstorms may occur into parts of the Midwest, and also across portions of the Carolinas and Virginia into northeast Georgia. ...Great Lakes to the Mid Mississippi Valley... Moderate instability is expected to develop ahead of a cold front that should extend from eastern Lower MI southwest into OK this afternoon, with MLCAPE on the order of 2000 J/kg. Modestly enhanced westerly mid-level flow across Lower MI will contribute to 25-35 kts of deep-layer shear, and this should prove sufficient for organized multicell storms. Scattered thunderstorm development is expected this afternoon as weak height falls/ascent overspreads the Slight Risk area, and where somewhat greater storm coverage is expected. Substantial boundary layer heating will result in steep low-level lapse rates, and the strongest storms/clusters will be capable of damaging gusts and isolated severe hail. Farther southwest, mid-level flow will be weaker than across the Great Lakes, but higher MLCAPE and negligible CINH will be present. Scattered thunderstorms should develop along the front after 18-19z, tending to cluster with time, and pose a risk for strong/damaging gusts and perhaps hail. ...Southern Appalachians to the Southern Mid-Atlantic... Diurnal heating of a very moist air mass (mid/upper 70s surface dew points and PW generally above 1.75 inches) will result in strong instability, with pockets of MLCAPE in excess of 3000 J/kg and effectively no CINH. Despite very weak mid-level flow of 10-15 kts, scattered thunderstorms developing near a weak front, and over higher terrain, will pose a risk for a few wet microbursts/strong wind gusts through this afternoon. ..Bunting/Squitieri.. 08/30/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Fri Aug 30 2024 Valid 301630Z - 311200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF EASTERN LOWER MICHIGAN... ...SUMMARY... Scattered strong to severe thunderstorms are possible across eastern Lower Michigan this afternoon, with damaging winds the main threat. Isolated strong to severe thunderstorms may occur into parts of the Midwest, and also across portions of the Carolinas and Virginia into northeast Georgia. ...Great Lakes to the Mid Mississippi Valley... Moderate instability is expected to develop ahead of a cold front that should extend from eastern Lower MI southwest into OK this afternoon, with MLCAPE on the order of 2000 J/kg. Modestly enhanced westerly mid-level flow across Lower MI will contribute to 25-35 kts of deep-layer shear, and this should prove sufficient for organized multicell storms. Scattered thunderstorm development is expected this afternoon as weak height falls/ascent overspreads the Slight Risk area, and where somewhat greater storm coverage is expected. Substantial boundary layer heating will result in steep low-level lapse rates, and the strongest storms/clusters will be capable of damaging gusts and isolated severe hail. Farther southwest, mid-level flow will be weaker than across the Great Lakes, but higher MLCAPE and negligible CINH will be present. Scattered thunderstorms should develop along the front after 18-19z, tending to cluster with time, and pose a risk for strong/damaging gusts and perhaps hail. ...Southern Appalachians to the Southern Mid-Atlantic... Diurnal heating of a very moist air mass (mid/upper 70s surface dew points and PW generally above 1.75 inches) will result in strong instability, with pockets of MLCAPE in excess of 3000 J/kg and effectively no CINH. Despite very weak mid-level flow of 10-15 kts, scattered thunderstorms developing near a weak front, and over higher terrain, will pose a risk for a few wet microbursts/strong wind gusts through this afternoon. ..Bunting/Squitieri.. 08/30/2024 Read more

No Mesoscale Discussions are in effect as of Fri Aug 30 16:29:01 UTC 2024.

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