SPC MD 781

4 days 8 hours ago
MD 0781 CONCERNING SEVERE THUNDERSTORM WATCH 248... FOR PARTS OF NORTHEAST CO...SOUTHWEST NE AND NORTHWEST KS
Mesoscale Discussion 0781 NWS Storm Prediction Center Norman OK 0742 PM CDT Wed May 14 2025 Areas affected...parts of northeast CO...southwest NE and northwest KS Concerning...Severe Thunderstorm Watch 248... Valid 150042Z - 150215Z The severe weather threat for Severe Thunderstorm Watch 248 continues. SUMMARY...A cluster of severe storms should continue eastward across WW248. Damaging winds and hail are likely. Local extensions of WW248 will be needed. DISCUSSION...As of 0035 UTC, regional radar analysis showed a cluster of severe storms stretching from southern and western NE, into northeastern CO and approaching northwest KS. Several reports of damaging winds and hail have been received with these storms over the past 2 hours. The severe risk is expected to continue this evening as storms gradually move eastward into increasingly more buoyant air near the north/south oriented stationary front. 45 kt of deep-layer shear and 500-1500 J/kg of MUCAPE will support storm organization with high-based supercell structures (ML LCL > 2500 M AGL) and linear clusters. CAM guidance and radar trends suggest additional upscale growth is likely with time as the low-level jet increases. Later tonight this may focus the severe risk northeastward into southern and central NE. Until then, a severe threat will persist across parts of Northwest KS and southern NE. A local extension of WW248 will likely be needed to cover the increasing risk for hail and damaging gusts this evening. ..Lyons.. 05/15/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GID...LBF...GLD...BOU...CYS... LAT...LON 41290316 40950059 40070016 39460016 39260176 39290312 41290316 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

SPC Severe Thunderstorm Watch 247 Status Reports

4 days 9 hours ago
WW 0247 Status Updates
STATUS REPORT ON WW 247 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..SPC..05/14/25 ATTN...WFO...LBF...ABR...UNR... STATUS REPORT FOR WS 247 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC005-009-017-029-031-041-063-075-085-091-101-103-111-113-115- 117-135-149-171-150040- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BLAINE BROWN CHASE CHERRY CUSTER FRONTIER GRANT HAYES HOOKER KEITH KEYA PAHA LINCOLN LOGAN LOUP MCPHERSON PERKINS ROCK THOMAS SDC065-075-085-095-117-119-121-123-150040- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE HUGHES JONES LYMAN MELLETTE STANLEY SULLY TODD TRIPP THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE Read more

SPC Severe Thunderstorm Watch 248 Status Reports

4 days 9 hours ago
WW 0248 Status Updates
STATUS REPORT ON WW 248 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 N LIC TO 25 WSW SNY TO 20 NE BFF. ..LYONS..05/14/25 ATTN...WFO...BOU...GLD...CYS...LBF... STATUS REPORT FOR WS 248 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC075-095-115-121-125-150040- CO . COLORADO COUNTIES INCLUDED ARE LOGAN PHILLIPS SEDGWICK WASHINGTON YUMA KSC023-150040- KS . KANSAS COUNTIES INCLUDED ARE CHEYENNE NEC033-049-057-069-123-150040- NE . NEBRASKA COUNTIES INCLUDED ARE CHEYENNE DEUEL DUNDY GARDEN MORRILL Read more

SPC Severe Thunderstorm Watch 247

4 days 9 hours ago
WW 247 SEVERE TSTM NE SD 142050Z - 150400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 247 NWS Storm Prediction Center Norman OK 350 PM CDT Wed May 14 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and Central Nebraska South-Central and Central South Dakota * Effective this Wednesday afternoon and evening from 350 PM until 1100 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 3 inches in diameter possible A tornado or two possible SUMMARY...Thunderstorms should continue to gradually increase in coverage and intensity this afternoon and evening. Supercells should pose a threat for large to very large hail potentially up to 2-3 inches in diameter, especially across parts of western into central Nebraska. Otherwise, scattered severe wind gusts may occur with any clusters that eventually form. A tornado or two also appears possible, mainly this evening. The severe thunderstorm watch area is approximately along and 45 statute miles east and west of a line from 35 miles north of Pierre SD to 25 miles east southeast of Imperial NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). 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 3 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 20030. ...Gleason Read more

SPC Severe Thunderstorm Watch 248

4 days 9 hours ago
WW 248 SEVERE TSTM CO KS NE 142235Z - 150400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 248 NWS Storm Prediction Center Norman OK 435 PM MDT Wed May 14 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northeast Colorado Northwest Kansas Nebraska Panhandle * Effective this Wednesday afternoon and evening from 435 PM until 1000 PM MDT. * Primary threats include... Scattered damaging winds likely with isolated significant gusts to 80 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...An intensifying cluster of thunderstorms over northeast Colorado will track eastward through the evening, posing a risk of damaging winds gusts and some hail. The severe thunderstorm watch area is approximately along and 65 statute miles north and south of a line from 50 miles west northwest of Akron CO to 10 miles northeast of Imperial NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). 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 247... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 70 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 26035. ...Hart Read more

SPC MD 779

4 days 11 hours ago
MD 0779 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF NORTHEAST COLORADO AND THE SOUTHERN NE PANHANDLE
Mesoscale Discussion 0779 NWS Storm Prediction Center Norman OK 0456 PM CDT Wed May 14 2025 Areas affected...parts of northeast Colorado and the southern NE Panhandle Concerning...Severe potential...Watch possible Valid 142156Z - 142330Z Probability of Watch Issuance...40 percent SUMMARY...High-based showers and storms moving off the higher terrain may pose a risk for isolated damaging gusts and small hail initially. Additional development/upscale growth could occur later this evening with a greater severe risk focused over northeast CO and southern NE. Trends are being monitored for a possible WW. DISCUSSION...As of 2145 UTC, regional radar and satellite imagery showed initial high-based convection has developed across the higher terrain of northeastern CO and southern WY. Supported predominately by broad northeasterly upslope ahead of a cold front, the environment across northern CO is not particularity unstable (MUCAPE < 500 J/kg) with dewpoints in the low 30s F. However, steep low and mid-level lapse rates greater than 8 C/km are present. This will allow for an isolated severe threat initially, with potential for more organized storms later this evening. Recent CAM guidance and radar trends suggests an isolated severe threat (35-50 kt gusts and small hail) may persist across the I-25 corridor over the next few hours. Given the potential for outflow interactions, additional storm development also appears likely. This may eventually result in a more coherent cluster of storms across northeastern CO where 40+ kt of deep-layer shear and more buoyancy could support greater storm organization. This may favor a greater risk for severe winds and hail with an organized cluster/MCS. While confidence in initial storm evolution and the resulting severe threat is low, some severe risk is likely present. Severe trends will continue to be monitored for a possible weather watch. ..Lyons/Hart.. 05/14/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 39100475 39410540 40470509 41050452 41100447 41570268 41480197 41000169 40020173 39590229 39380337 39100475 MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

SPC Day 3-8 Fire Weather Outlook

4 days 11 hours ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0453 PM CDT Wed May 14 2025 Valid 161200Z - 221200Z An upper-level trough and associated surface low over the Northern Plains on Day 3/Friday will push through the Great Lakes Region by Day 5/Sunday. An active upper-wave pattern will persist across CONUS with another upper-level trough moving into the Western U.S. by Day 5/Sunday, gradually pushing into the Eastern U.S. through Day 8 where widespread rainfall is expected. Fire weather concerns should remain concentrated across portions of the Southwest where dry fuels and recent active fire activity amid drought conditions have occurred. A broad ridging pattern begins to build across the West by the middle of next week promoting generally light surface winds but above normal temperatures and dry conditions, which will aid in the curing/drying of fuels. ...Southwest... A multi-day fire weather threat will persist across parts of the southwest through early next week. Modest mid-level flow over a well-mixed boundary layer should allow for gusty southwest winds across southeastern Arizona and southern New Mexico on Day 4/Saturday. A mid-level jet max rounding the base of the incoming upper-level trough into the western U.S. should promote at least Elevated if not Critical fire weather conditions across southern New Mexico where dry fuels and drought persist on Day 5-6/Sunday-Monday. 40 percent Critical probabilities were added to reflect higher confidence of fire weather threat. ..Williams.. 05/14/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook

4 days 11 hours ago
SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0453 PM CDT Wed May 14 2025 Valid 161200Z - 221200Z An upper-level trough and associated surface low over the Northern Plains on Day 3/Friday will push through the Great Lakes Region by Day 5/Sunday. An active upper-wave pattern will persist across CONUS with another upper-level trough moving into the Western U.S. by Day 5/Sunday, gradually pushing into the Eastern U.S. through Day 8 where widespread rainfall is expected. Fire weather concerns should remain concentrated across portions of the Southwest where dry fuels and recent active fire activity amid drought conditions have occurred. A broad ridging pattern begins to build across the West by the middle of next week promoting generally light surface winds but above normal temperatures and dry conditions, which will aid in the curing/drying of fuels. ...Southwest... A multi-day fire weather threat will persist across parts of the southwest through early next week. Modest mid-level flow over a well-mixed boundary layer should allow for gusty southwest winds across southeastern Arizona and southern New Mexico on Day 4/Saturday. A mid-level jet max rounding the base of the incoming upper-level trough into the western U.S. should promote at least Elevated if not Critical fire weather conditions across southern New Mexico where dry fuels and drought persist on Day 5-6/Sunday-Monday. 40 percent Critical probabilities were added to reflect higher confidence of fire weather threat. ..Williams.. 05/14/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Severe Thunderstorm Watch 247

4 days 12 hours ago
WW 247 SEVERE TSTM NE SD 142050Z - 150400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 247 NWS Storm Prediction Center Norman OK 350 PM CDT Wed May 14 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western and Central Nebraska South-Central and Central South Dakota * Effective this Wednesday afternoon and evening from 350 PM until 1100 PM CDT. * Primary threats include... Scattered damaging winds and isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 3 inches in diameter possible A tornado or two possible SUMMARY...Thunderstorms should continue to gradually increase in coverage and intensity this afternoon and evening. Supercells should pose a threat for large to very large hail potentially up to 2-3 inches in diameter, especially across parts of western into central Nebraska. Otherwise, scattered severe wind gusts may occur with any clusters that eventually form. A tornado or two also appears possible, mainly this evening. The severe thunderstorm watch area is approximately along and 45 statute miles east and west of a line from 35 miles north of Pierre SD to 25 miles east southeast of Imperial NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU7). 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 3 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 20030. ...Gleason Read more

SPC Day 2 Fire Weather Outlook

4 days 13 hours ago
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Wed May 14 2025 Valid 151200Z - 161200Z Elevated highlights were extended into northeast New Mexico, accounting for expected enhanced downslope west winds within a cooler, but still very dry air mass where relative humidity could fall to around 10 percent Thursday afternoon. Otherwise, forecast (see below) remains on track. ..Williams.. 05/14/2025 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed May 14 2025/ ...Synopsis... The upper trough over the western US will eject quickly eastward spreading strong mid-level flow atop the central Plains. A powerful lee cyclone will intensify further as it move into the Upper Midwest. A cold front and tailing dryline may support precipitation across parts of the Plains and Midwest States. Otherwise, dry and breezy conditions behind these features will favor some fire-weather risk. ...Southwest... Persistent westerly flow will continue across the Southwest Thursday. This will support another day of dry and windy conditions across parts of eastern AZ and southern NM. RH below 20% and winds of 15-20% amidst dry fuels will support widespread elevated to locally critical conditions. Some fire-weather risk may also extend into West TX behind an eastward mixing dryline. However, winds here may be somewhat weaker despite very warm surface temperatures and lower humidity. Locally elevated conditions are possible within drying fuels. ...Central Plains... As the strong surface low continues to deepen and shift eastward over the northern Plains and Midwest, a cold front will approach the central Plains Thursday/Thursday night. This could support some dry and breezy conditions behind the front within receptive fuels. Westerly gusts of 15-20 mph and RH below 25% could support elevated fire-weather conditions. However, some potential for rainfall in the preceding days may temporarily limit fuels. The relatively confined area and uncertainties on precipitation will preclude any highlights for now. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC May 14, 2025 2000 UTC Day 1 Convective Outlook

4 days 14 hours ago
SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0244 PM CDT Wed May 14 2025 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE NORTHERN/CENTRAL PLAINS... ...SUMMARY... Scattered strong to severe thunderstorms should occur over parts of the Dakotas and Nebraska this afternoon and evening, and far western Iowa and southwest Minnesota overnight. Very large hail, severe wind gusts, and a couple of tornadoes all appear possible. ...20z Update... No changes are needed to the D1 Convective Outlook. Severe storms are expected across the northern/central Plains this afternoon and evening as an upper low moves eastward with a surface cold front. Latest data from 18z RAOBs across Nebraska shows weak mid-level capping still in place across the area near North Platte, which much stronger MLCIN further east near Omaha. Ongoing elevated post frontal convection will continue before further convective development occurs later this afternoon and evening. These storms will have potential for very large hail, damaging wind, and a couple of tornadoes. See MCD#777 for more information on this threat in the near term. See previous discussion for more information below. ..Thornton/Gleason.. 05/14/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Wed May 14 2025/ ...Northern/Central Plains... An upper trough over the western states will pivot eastward today while gradually acquiring a negative tilt over the northern/central Plains by late tonight. At the surface, a front extending over the Dakotas should stall in a nearly north-south orientation later today. Shallow low-level moisture will continue to stream northward this afternoon ahead of the primary surface low, which is forecast to consolidate over western KS/southwest NE by early evening. A dryline will extend southward from this low over much of the central/southern Plains, but strong capping should generally limit convective development with southward extent through much of the day. Daytime heating of the modestly moist low-level airmass, combined with somewhat steepened mid-level lapse rates, will encourage around 1500-3000 J/kg of MLCAPE by mid afternoon. Stronger instability will likely exist with southward extent into NE, where slightly greater low-level moisture should be present. Mainly unidirectional/ southerly wind profiles along/near the front this afternoon suggest that initial convective development will be messy, with numerous updraft and outflow interactions. Still, the strongest of these initial cores should pose some risk for hail and wind gusts. Initially high-based convection is also forecast to develop across the central High Plains (northeast CO vicinity) by late afternoon/early evening, and spread northeastward across NE. A greater threat for sustained supercells remains apparent with southward extent across NE this evening, where stronger deep-layer shear somewhat more orthogonal to the surface boundaries should be present. Isolated very large hail (up to 2-3 inches in diameter) will be possible with any discrete cells, while severe wind gusts should become an increasing concern as convection grows upscale into a bowing cluster through the evening and early overnight hours. There should also be a narrow spatial/temporal window for a couple of tornadoes this evening across parts of NE as a low-level jet modestly strengthens and 0-1 km SRH increases. ...Southeast and Southern Mid-Atlantic into the Ohio Valley... A weak mid/upper trough will drift eastward today from the Appalachians towards the Carolinas and Mid-Atlantic. While mid-level winds and related effective bulk shear are expected to remain rather weak, some clustering/modest organization may occur with convection that will further develop this afternoon across NC into parts of southern VA. Occasional damaging winds should be the main threat with this activity as low-level lapse rates gradually steepen with continued diurnal heating. But, some hail may also occur. See Mesoscale Discussion 776 for more details on the short-term severe threat across this area. Across parts of the OH Valley, mainly elevated thunderstorms are forecast to develop this evening/overnight in a low-level warm advection regime. Sufficient MUCAPE and deep-layer shear is forecast to support an isolated threat for mainly large hail with this activity. Read more

SPC May 14, 2025 1930 UTC Day 3 Severe Thunderstorm Outlook

4 days 14 hours ago
SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0232 PM CDT Wed May 14 2025 Valid 161200Z - 171200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SOUTHEAST MISSOURI...SOUTHERN ILLINOIS/INDIANA...SOUTHWEST OHIO...AND PORTIONS OF WESTERN TO NORTHERN KENTUCKY... ...SUMMARY... Severe thunderstorms are expected across the Middle Mississippi and Ohio Valley region Friday afternoon and evening. All-severe hazards are possible with this activity. More isolated severe thunderstorms will extend southwestward into northeast Texas, and northeast into the Mid-Atlantic. ...Mid-South/Ohio Valley vicinity... An upper trough over the southern High Plains will pivot quickly east/northeast across the Midwest on Friday. As this occurs, strong mid/upper southwesterly flow will overspread the region, with a 500 mb jet around 70-90 kt forecast. At the surface, A very moist airmass will be in place from southern MO into southern IL and northeast into OH. Increasing southerly low-level flow ahead of a surface cold front will allow a warm front, roughly along the I-70 corridor at mid-morning, to lift north toward the northern IL/IN/OH through the afternoon. Cooling aloft will result in steep midlevel lapse rates atop the mid/upper 60s F dewpoint surface warm sector, resulting in strong destabilization. A low-level jet around 45-65 kt is forecast to overspread the region from peak heating into the evening, coincident with increasing large-scale ascent. Both the eastward-advancing cold front/dryline across MO, and the warm front vicinity will be a focus for convective initiation. One or more bowing clusters is possible, in addition to more discrete supercells. Given vertically veering supercells wind profiles, significant severe storms appear possible -- with a risk for all hazards accompanying this activity, including very large hail, tornadoes, and intense wind gusts. The southward extent of highest severe potential is a bit uncertain given orientation of surface boundaries and potential overnight convection in the Day 2/Thursday time period impacting parts of the KY vicinity. Eventually, a northeast to southwest line of storms will likely congeal during the late evening/nighttime hours and sag southward across KY into the TN Valley, with a gradually lessening severe risk with southward extent during the overnight hours. ...TX into OK/AR... With southwest extent, severe potential is a bit more uncertain/conditional. Some minor height rises may occur across TX and the into AR during the late afternoon/evening. Large-scale ascent will be weaker and any capping may be more difficult to overcome. Nevertheless, a very moist and unstable airmass will be in place amid supercell wind profiles. If storms can develop, very large hail and strong gusts will be possible. ...Mid-Atlantic Vicinity... Convection may be ongoing in a warm advection regime Friday morning as a weak shortwave impulse moves across the region through afternoon. Moderate mid/upper flow will support effective shear magnitudes around 25-35 kt, and be sufficient for some organized convection. Pockets of stronger heating downstream from morning activity will allow for weak to moderate destabilization. Isolated strong to severe storms producing hail and gusty winds will be possible. ..Leitman.. 05/14/2025 Read more

SPC May 14, 2025 1730 UTC Day 2 Convective Outlook

4 days 16 hours ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Wed May 14 2025 Valid 151200Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MINNESOTA INTO MUCH OF WISCONSIN...NORTHEAST ILLINOIS...SOUTHWEST LOWER MICHIGAN...AND NORTHERN INDIANA... ...SUMMARY... Severe thunderstorms are expected across parts of the upper Mississippi River Valley and Great Lakes region Thursday afternoon and evening. The primary risk with this activity is large to very large hail, tornadoes (a couple may be strong), and scattered wind damage. More isolated severe thunderstorms are expected through the lower Ohio River Valley, Ozarks Plateau, and parts of the Mid-Atlantic. ...Synopsis... An upper cyclone centered over the Dakotas, and attendant negative-tilt shortwave trough will deepen and spread northeast across the Upper Midwest on Thursday. A belt of enhanced mid/upper southwesterly flow will overspread the region, with a secondary jet streak oriented from the southern Plains to the Ohio Valley. At the surface, low pressure is forecast over eastern SD during the morning. The deepening surface low will lift north/northeast into northern MN through much of the forecast period. As this occurs, a warm front arcing southeast from the low to the Ohio Valley will lift northward during the afternoon and into the evening. This will allow a moist warm sector to lift northward across the Upper MS Valley and Great Lakes vicinity. Extending south from the surface low, a dryline will be in place from the Mid-MO valley into eastern OK and central TX. This feature will develop east/northeast across MN/WI/IA/MO/IL through the evening. Severe thunderstorm activity is expected near the triple point, and along the warm front and dryline (where a capping inversion is able to be overcome). ...Upper Midwest/Great Lakes vicinity... Convection will likely be ongoing Thursday morning near the surface low and beneath the upper low. Cold temperatures aloft will support steepened midlevel lapse rates within modest boundary layer moisture across the eastern Dakotas. Hail will be possible with this activity. Supercell wind profiles are also expected into late morning, and additional low-topped convection may develop from late morning into early afternoon, posing a risk of hail, gusty winds and a tornado or two across the eastern Dakotas. By afternoon, mid-60s F dewpoints are expected within a somewhat narrow warm sector from central MN southeast into WI and northern IL. As large-scale ascent increases, thunderstorms are expected to develop in an arc from east-central MN into southeast WI on the nose of a 40-50 kt low-level jet and midlevel dry slot. Vertically veering winds will produce supercell wind profiles. Low-level hodographs will become enlarged, in part due to the increasing low-level jet, but also within the warm front zone. Additionally, steep midlevel lapse rates and MLCAPE greater than 2500 J/kg are possible. This should support robust updrafts and rapidly increasing storm intensity once initiation occurs. Large to very large hail (up to 3 inch diameter) and tornadoes (a couple may be strong) appear possible within the moisture-rich, favorably sheared warm sector. Given strong 850-700 mb flow and steepening low-level lapse rates where strong heating occurs, severe gust potential is also expected. Current thinking is that given the orthogonal nature of low-level flow to the surface boundaries, supercell storm mode may be favored, with perhaps a trend toward bowing segment during the evening. A gust to 80 mph cannot be ruled out, but given uncertainty in storm mode transitioning to or favoring linear segments have held off on adding a sig-wind delineation. The bands of severe storms should develop northeast with time into the evening, with a gradual weakening trend expected across Upper and Lower MI. ...Northern IL/IN into OH/PA vicinity... Storm coverage is more uncertain with southward extent due to increasing capping in the 850-700 mb layer, and weaker large-scale ascent. Nevertheless, isolated to widely scattered storms are expected to develop during the afternoon in a strongly unstable and moderately sheared environment. Supercells producing large hail, a couple of tornadoes and damaging gusts will be possible into the evening hours across IL/IN. Additional activity is expected to develop in the low-level warm advection regime during the evening/overnight hours across portions of OH/western PA. This activity may remain elevated, but would still pose a risk for hail, or perhaps isolated gusty winds if clustering occurs. ...Ozarks to Mid-South/Ohio Valley... Further south from southeast MO/southern IL into KY, modest height falls are forecast during the evening/overnight hours. This may be sufficient to either overcome capping, or to allow elevated convection to develop. Severe storms capable of damaging gusts,large hail and a tornado or two appear possible, though this risk is a bit more uncertain/conditional and coverage may be low. ...Mid-Atlantic... A moist, weakly capped air mass is expected to remain in place across the Mid-Atlantic through Thursday afternoon. While lapse rates will be modest after several days of convective overturning, temperatures warming into the upper 70s/low 80s will promote sufficient buoyancy for thunderstorm development. Upper ridging moving into the region will likely limit thunderstorm coverage, but convection developing along the Blue Ridge Mountains will mature in an environment with increasing deep-layer shear. A few organized cells appear possible with an attendant severe hail/wind threat. ..Leitman.. 05/14/2025 Read more

SPC May 14, 2025 1730 UTC Day 2 Convective Outlook

4 days 16 hours ago
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Wed May 14 2025 Valid 151200Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EAST-CENTRAL MINNESOTA INTO MUCH OF WISCONSIN...NORTHEAST ILLINOIS...SOUTHWEST LOWER MICHIGAN...AND NORTHERN INDIANA... ...SUMMARY... Severe thunderstorms are expected across parts of the upper Mississippi River Valley and Great Lakes region Thursday afternoon and evening. The primary risk with this activity is large to very large hail, tornadoes (a couple may be strong), and scattered wind damage. More isolated severe thunderstorms are expected through the lower Ohio River Valley, Ozarks Plateau, and parts of the Mid-Atlantic. ...Synopsis... An upper cyclone centered over the Dakotas, and attendant negative-tilt shortwave trough will deepen and spread northeast across the Upper Midwest on Thursday. A belt of enhanced mid/upper southwesterly flow will overspread the region, with a secondary jet streak oriented from the southern Plains to the Ohio Valley. At the surface, low pressure is forecast over eastern SD during the morning. The deepening surface low will lift north/northeast into northern MN through much of the forecast period. As this occurs, a warm front arcing southeast from the low to the Ohio Valley will lift northward during the afternoon and into the evening. This will allow a moist warm sector to lift northward across the Upper MS Valley and Great Lakes vicinity. Extending south from the surface low, a dryline will be in place from the Mid-MO valley into eastern OK and central TX. This feature will develop east/northeast across MN/WI/IA/MO/IL through the evening. Severe thunderstorm activity is expected near the triple point, and along the warm front and dryline (where a capping inversion is able to be overcome). ...Upper Midwest/Great Lakes vicinity... Convection will likely be ongoing Thursday morning near the surface low and beneath the upper low. Cold temperatures aloft will support steepened midlevel lapse rates within modest boundary layer moisture across the eastern Dakotas. Hail will be possible with this activity. Supercell wind profiles are also expected into late morning, and additional low-topped convection may develop from late morning into early afternoon, posing a risk of hail, gusty winds and a tornado or two across the eastern Dakotas. By afternoon, mid-60s F dewpoints are expected within a somewhat narrow warm sector from central MN southeast into WI and northern IL. As large-scale ascent increases, thunderstorms are expected to develop in an arc from east-central MN into southeast WI on the nose of a 40-50 kt low-level jet and midlevel dry slot. Vertically veering winds will produce supercell wind profiles. Low-level hodographs will become enlarged, in part due to the increasing low-level jet, but also within the warm front zone. Additionally, steep midlevel lapse rates and MLCAPE greater than 2500 J/kg are possible. This should support robust updrafts and rapidly increasing storm intensity once initiation occurs. Large to very large hail (up to 3 inch diameter) and tornadoes (a couple may be strong) appear possible within the moisture-rich, favorably sheared warm sector. Given strong 850-700 mb flow and steepening low-level lapse rates where strong heating occurs, severe gust potential is also expected. Current thinking is that given the orthogonal nature of low-level flow to the surface boundaries, supercell storm mode may be favored, with perhaps a trend toward bowing segment during the evening. A gust to 80 mph cannot be ruled out, but given uncertainty in storm mode transitioning to or favoring linear segments have held off on adding a sig-wind delineation. The bands of severe storms should develop northeast with time into the evening, with a gradual weakening trend expected across Upper and Lower MI. ...Northern IL/IN into OH/PA vicinity... Storm coverage is more uncertain with southward extent due to increasing capping in the 850-700 mb layer, and weaker large-scale ascent. Nevertheless, isolated to widely scattered storms are expected to develop during the afternoon in a strongly unstable and moderately sheared environment. Supercells producing large hail, a couple of tornadoes and damaging gusts will be possible into the evening hours across IL/IN. Additional activity is expected to develop in the low-level warm advection regime during the evening/overnight hours across portions of OH/western PA. This activity may remain elevated, but would still pose a risk for hail, or perhaps isolated gusty winds if clustering occurs. ...Ozarks to Mid-South/Ohio Valley... Further south from southeast MO/southern IL into KY, modest height falls are forecast during the evening/overnight hours. This may be sufficient to either overcome capping, or to allow elevated convection to develop. Severe storms capable of damaging gusts,large hail and a tornado or two appear possible, though this risk is a bit more uncertain/conditional and coverage may be low. ...Mid-Atlantic... A moist, weakly capped air mass is expected to remain in place across the Mid-Atlantic through Thursday afternoon. While lapse rates will be modest after several days of convective overturning, temperatures warming into the upper 70s/low 80s will promote sufficient buoyancy for thunderstorm development. Upper ridging moving into the region will likely limit thunderstorm coverage, but convection developing along the Blue Ridge Mountains will mature in an environment with increasing deep-layer shear. A few organized cells appear possible with an attendant severe hail/wind threat. ..Leitman.. 05/14/2025 Read more

SPC Day 1 Fire Weather Outlook

4 days 16 hours ago
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1152 AM CDT Wed May 14 2025 Valid 141700Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR EASTERN ARIZONA...SOUTHERN/CENTRAL NEW MEXICO AND FAR WEST TEXAS... Despite cooler temperatures behind a cold front moving through New Mexico, a very dry post frontal air mass along with strong southwest winds will support Critical fire weather conditions across portions of central and southern New Mexico into far West Texas through today. Latest model guidance consensus shows a corridor of sustained southwest winds of 25-35 mph from southwest New Mexico with downslope wind enhancement extending into leeward sides of the Sandia-Manzano and Sacramento Mountains. These winds combined with drying fuels and relative humidity dropping into the 10-15 percent range this afternoon supported a slight northeastward extension of Critical highlights into east-central New Mexico. ..Williams.. 05/14/2025 .PREV DISCUSSION... /ISSUED 0156 AM CDT Wed May 14 2025/ ...Synopsis... A broad upper trough over the western US is forecast to deepen as it moves eastward over the central US. A lee low and dryline will strengthen over the Plains, supporting dry and breezy conditions over much of the western and central CONUS. While strong southerly winds are also possible ahead of the deepening surface low, returning surface moisture and precipitation chances are also expected, complicating some fire-weather potential. Critical fire-weather conditions appear most likely over parts of the Southwest. ...Southwest... Moderate mid-level flow at the base of the ejecting upper-trough will support westerly downslope winds of 20-25 mph across parts of the Southwest this afternoon and evening. A very dry surface pattern is expected to continue with above normal temperatures and little recent rainfall. This should support widespread RH below 15%. With sufficient fuels in place, and additional drying expected, several hours of critical fire-weather conditions are likely over southeastern AZ into southern NM and west TX. ...Central and Northern Plains... A strong lee low with a trailing dryline will gradually deepen as the upper trough begins to move over the Plains. Dry downslope flow is possible over parts of the central/northern Plains into the Upper Midwest behind the strengthening dryline. With RH minimums below 30% and wind gusting to 20 mph, some elevated fire-weather threat may be possible across parts of CO/KS and NE into the Dakotas and western MN. However, the strongest meteorological conditions are not expected to overlap with areas of supportive fuels given past rainfall and additional rain through the period. Increasing surface moisture may also limit any appreciable overlap. This will favor a more localized threat with only isolated elevated fire-weather conditions expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more
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