Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1154 AM CDT Mon Apr 17 2023 Valid 171700Z - 181200Z The previous forecast remains valid with only minor adjustments for the latest guidance. Isolated dry thunderstorms are expected over portions of the southern High Plains along with gusty winds and low humidity. Locally elevated fire-weather conditions are also possible across the eastern US, but confidence remains too low to add an Elevated area given widespread wetting rain. Please see the previous discussion for more information. ..Lyons.. 04/17/2023 .PREV DISCUSSION... /ISSUED 0209 AM CDT Mon Apr 17 2023/ ...Synopsis... A mid-level ridge will overspread the Plains states as an upper trough pivots toward New England. A departing surface low will encourage broad, dry westerly surface winds across much of the OH/TN Valleys and points eastward. Surface lee troughing across the southern High Plains will also develop by afternoon peak heating, encouraging both dry/windy surface conditions, and isolated dry thunderstorm development. ...Southern High Plains... By afternoon peak heating, 15 mph sustained southerly surface winds overlapping 15-20 percent RH are likely across portions of northeast NM into the TX and OK Panhandles and northwestern OK. Elevated highlights have been added where the most favorable overlap of dry/windy conditions and receptive fuels exists. Deep-layer ascent overspreading a relatively deep and dry but marginally buoyant boundary layer will encourage high-based thunderstorm development during the afternoon. The storms should be fast moving and isolated enough such that appreciable rainfall accumulations will be unlikely. Isolated dry thunderstorm highlights have been introduced where lightning strikes may occur amid dry grasses. ...OH/TN Valleys into the Appalachians... Widespread breezy, occasionally dry conditions are likely to the south of the surface low, with relative humidity dropping into the 20-30 percent range by afternoon peak heating. Several areas have received appreciable rainfall accumulations within the past week. As such, the potential for wildfire-spread should remain localized. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Sun Apr 16 21:28:01 UTC 2023.

MD 0546 CONCERNING HEAVY SNOW FOR PORTIONS OF WESTERN WISCONSIN AND EASTERN MINNESOTA
Mesoscale Discussion 0546 NWS Storm Prediction Center Norman OK 0354 PM CDT Sun Apr 16 2023 Areas affected...portions of western Wisconsin and eastern Minnesota Concerning...Heavy snow Valid 162054Z - 162300Z SUMMARY...Moderate to heavy snow with rates 1"+/hr ongoing. DISCUSSION...A band of moderate to heavy snow is ongoing near La Crosse, WI with reported rates up to 1.5"/hr. Temperatures are hovering around freezing regionally with stations within the heaviest portion of the snowband dropping down to freezing in the observations along and near the Mississippi River from La Crosse to Winona over the last couple of hours. RAP sounding profiles from within this region indicate deep saturation into the dendritic growth zone and mid-level lapse rates around 6.5 C/km, supporting efficient snow production and rates up to 1-1.5"/hr. Heavy snow with gusts around 25-30 mph will lead to reduced visibility to around 1/4-1/2 mi at times. ..Thornton/Grams.. 04/16/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ARX...MPX... LAT...LON 44529205 44569172 44469147 44339139 44179128 44009107 43959102 43749064 43589072 43559090 43569110 43679137 43949170 44149192 44259203 44529205 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0243 PM CDT Sun Apr 16 2023 Valid 162000Z - 171200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE GREAT LAKES REGION TO THE SOUTHEAST... ...SUMMARY... A couple of instances of strong winds and marginal hail remain possible across central and south Florida. A strong gust or two may also occur into this evening from eastern Upper Great Lakes and Lower Great Lakes, into the Southeast. ...Discussion... Prior reasoning, and outlook areas, continue to reflect current expectations. As such, aside from minor line adjustments, no changes appear necessary for this outlook issuance. ..Goss.. 04/16/2023 .PREV DISCUSSION... /ISSUED 1123 AM CDT Sun Apr 16 2023/ ...Central/south FL... Greater than weak buoyancy in the CONUS today will be confined to the peninsula south of a remnant outflow boundary in north-central FL, with the largest values of 2000-3000 J/kg MLCAPE across south FL. The larger CAPE regime should remain coincident with weaker deep-layer shear, as moderate mid-level westerlies across central FL lie within the buoyancy gradient. Scattered to widespread thunderstorm development is likely later this afternoon from the interior peninsula to the Atlantic coast sea breeze. The strongest storms will offer primary threats of isolated severe hail and damaging winds. There is low confidence regarding the evolution of a large MCS over the central Gulf. But there is potential for a remnant MCV to approach the Gulf coast of central/south FL tonight, with a lingering threat for isolated wind damage and perhaps marginal hail. ...Lower Great Lakes to the Southeast... A rather large area of lower-end damaging wind potential from strong to locally severe gusts remains evident this afternoon and evening. The relatively most favorable corridor for this to occur appears to be over the Upper OH Valley where cloud breaks were most pronounced this morning ahead of the progressive cold front. Within the warm sector ahead of the front, mid-level lapse rates will remain poor and buoyancy meager (MLCAPE less than 500 J/kg) with modest effective bulk shear as stronger deep-layer winds remain confined along/to the cool side of the front. Still, a broken band of lower-topped convection should develop within an arc along the front from Lower MI to the central Appalachians this afternoon and spread northeast across the Lower Great Lakes to the Mid-Atlantic States into this evening. Sporadic damaging winds should be expected from occasional strong gusts. Farther south in the Southeast, a remnant MCV along the AL/FL border should help focus isolated to scattered thunderstorm development near/just ahead of the trailing cold front pushing east. Some attempt at boundary-layer moisture recovery ahead of it, in the wake of yesterday's MCS that tracked across the central Gulf coast to the FL/GA border area, should support a threat for isolated strong gusts and localized damaging winds to the GA/SC coast through this evening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0156 PM CDT Sun Apr 16 2023 Valid 171200Z - 181200Z ...Eastern NM, TX Panhandle, and far western OK... Hi-res model guidance has come into better agreement on the potential for isolated to widely scattered dry thunderstorms over dry fuels D2/Monday. Area model soundings show deep inverted Vs with PWATs below 1 inch over much of the Panhandle and eastern NM. Fast storm speeds and little precipitation may favor higher ignition efficiency with lighting over the dry area fuels. Isolated Dry Thunderstorm probabilities have been added to the outlook. In addition to the risk for dry T, gusty surface winds of 15-20 mph and RH below 25% will support a risk for elevated fire-weather conditions. See the previous discussion. ..Lyons.. 04/16/2023 .PREV DISCUSSION... /ISSUED 0117 AM CDT Sun Apr 16 2023/ ...Synopsis... An upper ridge will build into the Plains states as a mid-level trough impinges on the East Coast tomorrow/Monday. A surface low will meander across the Great Lakes vicinity, promoting widespread windy, occasionally dry conditions from the MS River to the Carolina Piedmont through Monday afternoon. While Elevated meteorological surface conditions are likely in spots, multiple rounds of rain east of the MS River should have tempered fuels enough to keep wildfire-spread concerns more localized. Across the southern High Plains though, dry southerly surface winds are likely by afternoon as a surface lee trough becomes established over the region due to the approach of another mid-level trough. By afternoon peak heating, 15 mph sustained south-southwesterly winds will overlap with 15-20 percent RH from the CO/NM border into far northwest OK, where fuels should be dry enough to support some wildfire-spread potential, necessitating the introduction of Elevated highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sun Apr 16 2023 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not expected across the continental United States Monday and Monday night. ...Discussion... A deep upper low centered over the Upper Great Lakes region early Monday is forecast to drift slowly northeastward across Lake Huron, toward the Ottawa River Valley. Broader cyclonic flow surrounding this low will continue to encompass that portion of the U.S. east of the Mississippi Valley. Meanwhile in the West, an upper low is forecast to linger off the British Columbia coast, while a short-wave trough rotating around the southern periphery of the low will move inland across the Pacific Northwest during the second half of the period. At the surface, a cold front -- trailing southward from a triple point in the vicinity of southwestern New England early -- will progress eastward across the western Atlantic, lingering only across south Florida. Meanwhile, a cold front is forecast to advance southeastward across the western states, as the aforementioned upper trough advances toward/into the Pacific Northwest region. Showers and a few thunderstorms are expected near and ahead of the front lingering over south Florida, while showers and sporadic lightning will also affect portions of the West in conjunction with the advancing storm system. Finally, isolated, high-based, diurnal convection is forecast to develop across parts of eastern New Mexico and adjacent western Texas. Daytime heating across this region will combine with modest low-level moisture returning northward on southerly flow on the back side of a Gulf of Mexico surface high, to yield weak afternoon destabilization. While a locally strong gust or two -- aided by evaporative cooling within the dry sub-cloud boundary layer -- will be possible, any severe potential appears likely to remain below the 5% threshold that would warrant any areal inclusion. Convection should dissipate through early evening. ..Goss.. 04/16/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Sun Apr 16 2023 Valid 161700Z - 171200Z ...Central Plains... Morning surface obs and visible satellite imagery show clearing skies and falling humidity are ongoing across much of central NE into north-central KS. Surface winds of 25-30 mph and higher gusts are being observed and should continue into the afternoon. The Elevated area was expanded eastward into portions of eastern NE where low-level winds will gust to 25-40 mph and RH values may fall to 20-25%. Pockets of dry fuels will likely be sufficient to support some risk for elevated to locally critical fire-weather concerns before cooler temperatures and higher RH develop this evening. See the previous discussion for additional information. ..Lyons.. 04/16/2023 .PREV DISCUSSION... /ISSUED 1256 AM CDT Sun Apr 16 2023/ ...Synopsis... A mid-level trough and associated surface low will move across the MS/OH Valley areas today, resulting in widespread deep-layer northwesterly flow overspreading the central Plains. Meanwhile, weak surface lee troughing across the southern High Plains will also support periodic bouts of dry and breezy surface conditions. Over the central Plains, guidance has trended windier and drier over much of Nebraska into Kansas and northern Oklahoma. Eastern parts of Nebraska and Kansas should experience Critical winds/RH by afternoon peak heating. However, much of this region also recently experienced appreciable rainfall accumulations, precluding the addition of fire weather highlights this outlook. Central portions of Nebraska and Kansas have received a little less rainfall recently, and newer guidance shows 15-20 mph sustained northwesterly winds overlapping 15-20 percent RH for at least a few hours during the afternoon. Since fuels should be at least modestly receptive to wildfire spread, Elevated highlights were added in a narrow corridor where dry/windy surface conditions and relatively more receptive fuels overlap. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0140 Status Updates
STATUS FOR WATCH 0140 HAS NOT BEEN ISSUED YET Read more

WW 140 SEVERE TSTM AR LA TX 152115Z - 160300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 140 NWS Storm Prediction Center Norman OK 415 PM CDT Sat Apr 15 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Arkansas Northwest Louisiana East Texas * Effective this Saturday afternoon and evening from 415 PM until 1000 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 2.5 inches in diameter possible A tornado or two possible SUMMARY...Multiple thunderstorm regimes are expected into late evening with semi-discrete supercells and clusters. Large hail and damaging winds will be the main threats. The severe thunderstorm watch area is approximately along and 50 statute miles east and west of a line from 70 miles south southwest of Shreveport LA to 30 miles west of Walnut Ridge AR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). 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 138...WW 139... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25035. ...Grams Read more

WW 0139 Status Updates
STATUS FOR WATCH 0139 HAS NOT BEEN ISSUED YET Read more

WW 139 TORNADO IL MO 152105Z - 160300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 139 NWS Storm Prediction Center Norman OK 405 PM CDT Sat Apr 15 2023 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southwest Illinois Southeast Missouri * Effective this Saturday afternoon and evening from 405 PM until 1000 PM CDT. * Primary threats include... A couple tornadoes possible Scattered damaging winds likely with isolated significant gusts to 75 mph possible Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible SUMMARY...Supercells evolving into a cluster with embedded line segments is expected to spread east across the Mid-Mississippi Valley. Hail transitioning to damaging wind should be the main threat, but a couple embedded tornadoes are possible as well. The tornado watch area is approximately along and 50 statute miles east and west of a line from 40 miles northwest of Alton IL to 35 miles east southeast of Poplar Bluff MO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). 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 137...WW 138... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 65 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Grams Read more

WW 0138 Status Updates
STATUS REPORT ON WW 138 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 NW DEQ TO 5 N FSM TO 30 S UMN TO 20 NNE UMN TO 25 NW SGF TO 45 WSW JEF TO 10 NNE COU. ..BENTLEY..04/15/23 ATTN...WFO...LZK...TSA...SGF...LSX... STATUS REPORT FOR WS 138 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC005-009-015-029-033-047-049-051-065-071-083-087-089-097-101- 105-113-115-127-129-131-137-141-143-149-152240- AR . ARKANSAS COUNTIES INCLUDED ARE BAXTER BOONE CARROLL CONWAY CRAWFORD FRANKLIN FULTON GARLAND IZARD JOHNSON LOGAN MADISON MARION MONTGOMERY NEWTON PERRY POLK POPE SCOTT SEARCY SEBASTIAN STONE VAN BUREN WASHINGTON YELL MOC007-009-027-029-043-051-055-059-065-067-071-073-077-091-093- 105-109-125-131-135-139-141-149-151-153-161-167-169-179-203-209- 213-215-219-221-225-229-152240- MO . MISSOURI COUNTIES INCLUDED ARE Read more

WW 138 SEVERE TSTM AR KS MO OK 151750Z - 160000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 138 NWS Storm Prediction Center Norman OK 1250 PM CDT Sat Apr 15 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western to northern Arkansas Far southeast Kansas Southern to central Missouri Far eastern Oklahoma * Effective this Saturday afternoon and evening from 1250 PM until 700 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 3 inches in diameter likely Scattered damaging winds likely with isolated significant gusts to 75 mph possible A tornado or two possible SUMMARY...Several supercells will develop across the Ozark Plateau region with a primary hazard of very large hail. Upscale growth into a line is expected later this afternoon across central Missouri and northern Arkansas with an increasing damaging wind threat. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 15 miles north northeast of Jefferson City MO to 35 miles east southeast of Poteau OK. 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 137... 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 23035. ...Grams Read more

MD 0530 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR EASTERN TEXAS
Mesoscale Discussion 0530 NWS Storm Prediction Center Norman OK 0357 PM CDT Sat Apr 15 2023 Areas affected...Eastern Texas Concerning...Severe potential...Watch possible Valid 152057Z - 152300Z Probability of Watch Issuance...40 percent SUMMARY...Thunderstorms posing a risk of damaging wind and hail are expected to develop within the next couple of hours. A Severe Thunderstorm watch is being considered. DISCUSSION...Towering cumulus has been developing along an eastward moving cold front in eastern Texas. Ahead of this development, MLCAPE is approaching 3000-4000 J/kg. Effective shear is marginal, around 20-30 kts. Initial development will pose a severe hail risk before mode transitions to become more linear as forcing for ascent increasing with eastward progression of the cold front. This area is being monitored for a potential Severe Thunderstorm Watch. ..Thornton/Grams.. 04/15/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SHV...HGX...FWD...EWX... LAT...LON 31169718 31519684 32369607 32449531 32259482 32109469 31759453 31409461 30979491 30619519 30529547 30339591 30269623 30269654 30319691 30359700 30399702 31169718 Read more

MD 0529 CONCERNING SEVERE THUNDERSTORM WATCH 138... FOR CENTRAL/SOUTHERN MISSOURI INTO PARTS OF NORTHERN/WEST-CENTRAL ARKANSAS
Mesoscale Discussion 0529 NWS Storm Prediction Center Norman OK 0338 PM CDT Sat Apr 15 2023 Areas affected...central/southern Missouri into parts of northern/west-central Arkansas Concerning...Severe Thunderstorm Watch 138... Valid 152038Z - 152245Z The severe weather threat for Severe Thunderstorm Watch 138 continues. SUMMARY...A threat for very large hail will continue across WW 138. An increasing risk for swaths of damaging gusts is expected in the next couple of hours as storms develop into a line as they spread east late this afternoon into early evening. DISCUSSION...A broken line of supercells/clusters are ongoing from central MO into northwest AR this afternoon. These storms have a history of producing mainly 1-2 inch hail, but some as large as 4 inches in diameter have been observed. Moderate instability/steep midlevel lapse rates and elongated hodographs will continue to support storms capable of severe hail for the next few hours. As convection continues shift eastward, storms are expected to congeal and develop upscale into a bow/QLCS. As this occurs, the risk for damaging gusts will increase across eastern portions of the watch area. See MCD 528 for downstream watch potential. ..Leitman.. 04/15/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LSX...LZK...SGF...TSA... LAT...LON 38529256 38809206 38739101 38369089 37269111 35519239 35019310 34739397 34729456 35339449 36929404 37709344 38529256 Read more

WW 0137 Status Updates
STATUS REPORT ON WW 137 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 85 E BVE TO 40 SSE MOB TO 15 E MOB TO 40 WNW GZH. ..BENTLEY..04/15/23 ATTN...WFO...MOB...LIX...JAN... STATUS REPORT FOR WS 137 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ALC003-152140- AL . ALABAMA COUNTIES INCLUDED ARE BALDWIN FLC033-113-152140- FL . FLORIDA COUNTIES INCLUDED ARE ESCAMBIA SANTA ROSA GMZ630-631-634-650-152140- CW . ADJACENT COASTAL WATERS INCLUDED ARE NORTH MOBILE BAY SOUTH MOBILE BAY Read more

WW 137 SEVERE TSTM AL LA MS CW 151620Z - 152100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 137 NWS Storm Prediction Center Norman OK 1120 AM CDT Sat Apr 15 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Far southwest Alabama Southeast Louisiana Southeast Mississippi Coastal Waters * Effective this Saturday morning and afternoon from 1120 AM until 400 PM CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph possible SUMMARY...A linear MCS should spread east across the central Gulf Coast through late afternoon with a threat for strong to locally severe wind gusts. The severe thunderstorm watch area is approximately along and 55 statute miles north and south of a line from 35 miles west northwest of New Orleans LA to 30 miles southeast of Mobile AL. 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 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27035. ...Grams Read more

MD 0528 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR EAST-CENTRAL/SOUTHEAST MISSOURI AND WEST-CENTRAL/SOUTHWEST ILLINOIS
Mesoscale Discussion 0528 NWS Storm Prediction Center Norman OK 0321 PM CDT Sat Apr 15 2023 Areas affected...east-central/southeast Missouri and west-central/southwest Illinois Concerning...Severe potential...Watch likely Valid 152021Z - 152215Z Probability of Watch Issuance...80 percent SUMMARY...Severe potential is expected to increase into late afternoon/early evening from east-central/southeast Missouri into west-central/southwest Illinois. A watch will likely be needed in the next couple hours. DISCUSSION...A broken line of severe supercells continues to develop and shift east/northeast across southwest into central MO and western AR across WW 138. East of the watch, airmass recovery has been slower due to earlier day convection. However, plenty of heating through the afternoon has allowed temperatures to warm into the mid/upper 70s with dewpoints increasing into the low 60s (mid/upper 60s further south toward the MS/OH River confluence/southeast MO vicinity). Combined with steep midlevel lapse rates, MLCAPE values have increased to around 1000-1500 J/kg late this afternoon, with some further destabilization expected. The expectation is that the supercell clusters further west will develop upward into a bow/QLCS as convection approaches the MS River/southeast MO. While some hail potential will continue, this upscale development will support an increasing threat for swaths of damaging gusts. Current KLSX VWP data indicate larger than previously expected low-level hodographs, with forecast guidance also indicating a corridor of greater low-level SRH extending southward along the MS River vicinity through this evening. If backed low-level winds persist, this could indicated some greater potential for mesovortex tornadoes as the line of convection surges eastward this evening. Timing is a bit uncertain as visible satellite indicated some attempts at convective development across central MO ahead of the ongoing supercells. If this activity develops further, a watch may be needed sooner downstream from WW 138. Regardless, a watch is expected across the MCD area in the next couple of hours. ..Leitman/Grams.. 04/15/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PAH...ILX...MEG...LSX... LAT...LON 38999122 39159129 39339121 39419096 39519055 39569019 39328973 38978931 38628908 38028898 37608897 37188896 36848931 36608972 36479024 36589077 36979085 37689071 38479083 38839101 38999122 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Sat Apr 15 2023 Valid 152000Z - 161200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF CENTRAL AND SOUTHERN MISSOURI AND ADJACENT SOUTHWESTERN ILLINOIS...SOUTHWARD TO NORTHERN LOUISIANA... ...SUMMARY... Severe risk will continue this afternoon and tonight -- with greatest potential focused across the Mid-Mississippi/Lower Missouri Valleys. Within the main risk area, very large hail and damaging winds will be the dominant hazards in terms of coverage, but a few tornadoes will be possible. ...Discussion... The ongoing convective/severe-weather event continues to unfold largely as described in prior outlooks, with the most substantial severe risk evolving at this time across far eastern Oklahoma and into southern Missouri and northwestern Arkansas. Here, supercell development is underway, with very large hail being reported. This event will continue to expand in coverage, as the all-hazard risk evolves across this region. Less widespread risk is forecast to expand southwestward over the next several hours, while local/limited risk -- primarily in the form of strong winds -- continues for a couple more hours over the central Gulf Coastal area. Aside from minor line adjustments to account for recent convective evolution, no substantial changes to outlook areas appear necessary with this update. ..Goss.. 04/15/2023 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Apr 15 2023/ ...Mid MS Valley to the Gulf coast... A shortwave trough over the central Great Plains will shift east into the Mid-MS Valley through tonight. This trough has two embedded impulses, one across central KS and the other in eastern CO. The latter is expected to become dominant as the trough and attendant mid-level jet amplify, centered on this evening. The leading impulse will likely aid in initial surface-based thunderstorm development in the Ozark Plateau, immediately ahead of the primary surface cyclone along the northern return of richer boundary-layer moisture from eastern OK/western AR. Activity will expand northeast in MO, as well as develop south along and ahead of an eastward-moving cold front through AR to southeast TX. Weak low-level shear and rather modest hodograph curvature suggests that large hail will be the primary initial threat. Significant severe hail will be possible owing to very steep mid-level lapse rates initially and ample buoyancy amid 30-40 kt effective bulk shear. How quickly storms grow upscale from discrete supercells into a QLCS is somewhat uncertain, but is most likely to occur first across MO/northern AR towards the Mid-MS Valley in the late afternoon to early evening. This will yield a corresponding increase in the damaging wind threat. The 12Z NAM is substantially stronger than the 15Z RAP and 00Z ECMWF with the degree of low-level mass response ahead of the line in the early evening, lowering confidence in the degree of embedded tornado threat. The northern line of storms will weaken into tonight as storms spread east of the Mid-MS Valley amid diminishing buoyancy with eastern extent. Farther south, a messier mix of semi-discrete supercells and clusters might evolve into a southeast-moving QLCS spreading across the Lower MS Valley tonight. Low confidence exists in this scenario given potential for multiple rounds of convection this afternoon and evening. An ongoing MCS across LA/far southern MS may continue east along the central Gulf Coast with a primary threat of strong to isolated severe gusts. The track of this MCS this morning has yielded a swath of convective overturning in its wake, suggesting that weak low-level warm theta-e advection along/atop its residual outflow could support redevelopment of scattered storms around peak heating. Deep-layer vertical shear will be weaker with southern extent, but steep lapse rates and large undisturbed warm-sector CAPE will support potential for large hail/damaging winds late this afternoon/evening. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0221 PM CDT Sat Apr 15 2023 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Portions of the central Plains... In the wake of departing cold front, strong northwest winds are expected through much of D2/Sunday from NE/KS into portions of northeastern OK. Model soundings show some diurnal heating and drying will favor lower afternoon RH of 20-30%. However, recent precipitation in the last 48 hours has resulted in widespread wetting rainfall of at least 0.1-0.25 inches over much of the eastern Plains. It remains unclear how receptive short-hour fuels are to fire spread given the recent rain and higher overnight humidity recoveries. Despite the fuels, the magnitude of strong gusts in the 25-40 mph range may still support some locally elevated to near-critical fire-weather conditions D2/Sunday afternoon. Confidence remains too low to introduce an Elevated area given questions on fuels and marginal RH values. See the previous discussion for more information. ..Lyons.. 04/15/2023 .PREV DISCUSSION... /ISSUED 0110 AM CDT Sat Apr 15 2023/ ...Synopsis... Surface high pressure and associated cooler temperatures will overspread the southern Plains as a mid-level ridge gradually builds overhead. Overall dry conditions should prevail across the southern High Plains. However, the lack of widespread overlapping dry and windy conditions in the latest guidance limits confidence for introducing fire weather highlights this outlook. A better chance for overlapping dry and windy conditions may occur across portions of the central Plains, with 20+ mph sustained northwesterly surface winds overlapping 20-30 percent RH by afternoon peak heating. However, fire weather highlights have been withheld since some guidance members suggest RH will be too high to support a significant wildfire-spread threat. In addition, portions of the east-central Plains are currently experiencing heavy rain due to scattered to widespread thunderstorms, making it difficult to pinpoint where dry and windy conditions will overlap with receptive fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more