Severe Storms

MD 0580 CONCERNING SEVERE THUNDERSTORM WATCH 152...155... FOR PORTIONS OF CENTRAL AND EASTERN TEXAS
Mesoscale Discussion 0580 NWS Storm Prediction Center Norman OK 0354 PM CDT Thu Apr 20 2023 Areas affected...portions of central and eastern Texas Concerning...Severe Thunderstorm Watch 152...155... Valid 202054Z - 202300Z The severe weather threat for Severe Thunderstorm Watch 152, 155 continues. SUMMARY...Large hail and gusty wind threat continues. More favorable corridor for significant hail developing across south-central Texas. DISCUSSION...Storms continue across WW152 and WW155, with occasional large hail up to 1.5" reported across portions of central and eastern Texas. Instances of large hail should persist as storms continue eastward into the more unstable air mass to the east. Deep layer shear remains weak but effective to organize semi-discrete cells, especially along the southern periphery of the front where deep layer shear is less parallel to the front and storm mergers and interactions are ongoing. In this region, the threat for significant hail (with some approaching 3 inches) will be the most likely in the near term as storms approach a region of MLCAPE around 3000 J/kg. ..Thornton/Grams.. 04/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SHV...HGX...FWD...EWX...SJT... LAT...LON 31329858 31799805 32129749 33019647 33839568 33869516 33839458 33659410 33419387 33149383 32839392 32429421 31919468 31319498 30919568 30669615 30439658 30269697 30209757 30219805 30369858 30739883 31329858 Read more

MD 0579 CONCERNING TORNADO WATCH 154... FOR NORTHERN IL....SOUTHERN WI
Mesoscale Discussion 0579 NWS Storm Prediction Center Norman OK 0341 PM CDT Thu Apr 20 2023 Areas affected...Northern IL....Southern WI Concerning...Tornado Watch 154... Valid 202041Z - 202215Z The severe weather threat for Tornado Watch 154 continues. SUMMARY...The threat for severe thunderstorms capable of all severe hazards, including tornadoes, will continue across northern IL and southern WI. DISCUSSION...A few discrete cells initialized along the front over the past hour and half, with a mostly discrete mode persisting until now. These cells have moved slightly off the front, supported by westerly/southwesterly deep-layer flow. If cell interactions can remain limited, these storms should continue to mature, with an associated threat for tornadogenesis. Storm mergers, whether from left splits or varying storm motion from more mature cells, could interrupt this maturing process. In either case, the downstream air mass remain modestly buoyant and strongly sheared and the threat for severe thunderstorms capable of all hazards will continue for the next few hours, particularly across northern IL. ..Mosier/Moore.. 04/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LOT...ILX...MKX...DVN... LAT...LON 42409039 43378990 43488863 42908806 41638797 40528874 40359073 41329075 42409039 Read more

WW 0155 Status Updates
STATUS REPORT ON WW 155 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..MOORE..04/20/23 ATTN...WFO...EWX...SJT... STATUS REPORT FOR WS 155 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS TXC013-019-021-029-031-053-055-091-095-123-127-137-149-163-171- 177-187-209-255-259-265-267-271-285-287-299-307-319-323-325-327- 385-411-413-435-453-463-491-493-507-202140- TX . TEXAS COUNTIES INCLUDED ARE ATASCOSA BANDERA BASTROP BEXAR BLANCO BURNET CALDWELL COMAL CONCHO DEWITT DIMMIT EDWARDS FAYETTE FRIO GILLESPIE GONZALES GUADALUPE HAYS KARNES KENDALL KERR KIMBLE KINNEY LAVACA LEE LLANO MCCULLOCH MASON MAVERICK MEDINA MENARD REAL SAN SABA SCHLEICHER SUTTON TRAVIS UVALDE WILLIAMSON WILSON ZAVALA THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES Read more

WW 155 SEVERE TSTM TX 201930Z - 210300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 155 NWS Storm Prediction Center Norman OK 230 PM CDT Thu Apr 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of South-central Texas * Effective this Thursday afternoon and evening from 230 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 3 inches in diameter possible SUMMARY...Slow-moving, transient supercells and multicell clusters should develop across the Edwards Plateau and Hill Country into this evening. More isolated cells may also develop east of the I-35 corridor. Large hail should be the primary hazard, with severe wind gust potential increasing into the evening. The severe thunderstorm watch area is approximately along and 75 statute miles north and south of a line from 70 miles southwest of Junction TX to 35 miles east southeast of Austin TX. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 151...WW 152...WW 153...WW 154... 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 550. Mean storm motion vector 30025. ...Grams Read more

WW 0153 Status Updates
STATUS REPORT ON WW 153 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..MOORE..04/20/23 ATTN...WFO...SHV...FWD...HGX... STATUS REPORT FOR WS 153 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC027-057-061-073-081-091-099-133-139-202140- AR . ARKANSAS COUNTIES INCLUDED ARE COLUMBIA HEMPSTEAD HOWARD LAFAYETTE LITTLE RIVER MILLER NEVADA SEVIER UNION LAC013-015-017-027-031-061-081-111-119-202140- LA . LOUISIANA PARISHES INCLUDED ARE BIENVILLE BOSSIER CADDO CLAIBORNE DE SOTO LINCOLN RED RIVER UNION WEBSTER OKC089-202140- OK . OKLAHOMA COUNTIES INCLUDED ARE MCCURTAIN Read more

WW 153 SEVERE TSTM AR LA OK TX 201850Z - 210200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 153 NWS Storm Prediction Center Norman OK 150 PM CDT Thu Apr 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southwest Arkansas Northwest Louisiana Far southeast Oklahoma Central to northeast Texas * Effective this Thursday afternoon and evening from 150 PM until 900 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A mix of supercells and multicell clusters are expected to develop and spread east through mid evening. Large hail will be the primary threat early, followed by damaging winds later. The severe thunderstorm watch area is approximately along and 100 statute miles east and west of a line from 35 miles northeast of Texarkana AR to 25 miles east southeast of Temple TX. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). 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 151...WW 152... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 27030. ...Grams Read more

WW 0152 Status Updates
STATUS REPORT ON WW 152 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SSW MKO TO 35 SSE SGF. ..MOORE..04/20/23 ATTN...WFO...LZK...TSA... STATUS REPORT FOR WS 152 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ARC005-009-011-013-015-019-023-025-029-033-039-045-047-049-051- 053-059-063-065-067-069-071-075-083-085-087-089-097-101-103-105- 109-113-115-117-119-121-125-127-129-131-135-137-141-143-145-147- 149-202140- AR . ARKANSAS COUNTIES INCLUDED ARE BAXTER BOONE BRADLEY CALHOUN CARROLL CLARK CLEBURNE CLEVELAND CONWAY CRAWFORD DALLAS FAULKNER FRANKLIN FULTON GARLAND GRANT HOT SPRING INDEPENDENCE IZARD JACKSON JEFFERSON JOHNSON LAWRENCE LOGAN LONOKE MADISON MARION MONTGOMERY NEWTON OUACHITA PERRY PIKE POLK POPE PRAIRIE PULASKI RANDOLPH SALINE SCOTT SEARCY SEBASTIAN SHARP STONE VAN BUREN WASHINGTON WHITE WOODRUFF YELL Read more

WW 152 SEVERE TSTM AR OK 201835Z - 210200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 152 NWS Storm Prediction Center Norman OK 135 PM CDT Thu Apr 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Arkansas Southeast Oklahoma * Effective this Thursday afternoon and evening from 135 PM until 900 PM CDT. * Primary threats include... Isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 65 mph possible SUMMARY...A mix of transient supercells and multicell clusters are expected through mid-evening along a cold front pushing east. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 30 miles northeast of Flippin AR to 30 miles southwest of Hot Springs AR. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). 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 151... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 25030. ...Grams Read more

WW 0151 Status Updates
STATUS REPORT ON WW 151 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 WNW HRO TO 10 NE TBN TO 5 ESE JEF TO 40 SW PIA. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 0578 ..MOORE..04/20/23 ATTN...WFO...LSX...ILX...SGF... STATUS REPORT FOR WS 151 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC005-009-013-017-021-027-039-049-051-061-083-107-115-117-119- 121-125-129-133-135-137-139-147-149-157-163-167-171-173-189- 202240- IL . ILLINOIS COUNTIES INCLUDED ARE BOND BROWN CALHOUN CASS CHRISTIAN CLINTON DE WITT EFFINGHAM FAYETTE GREENE JERSEY LOGAN MACON MACOUPIN MADISON MARION MASON MENARD MONROE MONTGOMERY MORGAN MOULTRIE PIATT PIKE RANDOLPH ST. CLAIR SANGAMON SCOTT SHELBY WASHINGTON MOC027-055-065-067-071-073-091-093-099-113-123-125-139-149-151- 153-161-163-179-183-186-187-189-203-213-215-219-221-229-510- 202240- Read more

WW 151 SEVERE TSTM IL MO 201820Z - 210100Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 151 NWS Storm Prediction Center Norman OK 120 PM CDT Thu Apr 20 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Central and southern Illinois Southwest to eastern Missouri * Effective this Thursday afternoon and evening from 120 PM until 800 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Scattered damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A few supercells and organized clusters should intensify and spread east across parts of Missouri into central and southern Illinois through early evening. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 15 miles north northwest of Springfield IL to 25 miles west southwest of West Plains MO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU1). 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 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24035. ...Grams Read more

MD 0578 CONCERNING SEVERE THUNDERSTORM WATCH 151... FOR SOUTHERN/EASTERN MO...WEST-CENTRAL IL
Mesoscale Discussion 0578 NWS Storm Prediction Center Norman OK 0310 PM CDT Thu Apr 20 2023 Areas affected...Southern/Eastern MO...West-Central IL Concerning...Severe Thunderstorm Watch 151... Valid 202010Z - 202145Z The severe weather threat for Severe Thunderstorm Watch 151 continues. SUMMARY...Threat for severe thunderstorms capable of large hail and damaging gusts continues across southern/eastern MO and west-central IL. DISCUSSION...Strong to severe thunderstorms continue along the cold front stretched from near BRL into far west-central IL southwestward through central and southern MO. Storms have quickly trended towards a linear/bowing line segment mode as they become more outflow dominant. This overall storm evolution is expected to continue, with the highest threat for large hail likely early in the storm lifecycle, trending towards more of a damaging wind threat thereafter. Most favorable corridor for continued severe currently appears to be east-central MO into west-central IL. Recent mesoanalysis estimates the downstream air mass is only modestly buoyant, and with some convective inhibition likely remaining. This is verified by recent visible satellite imagery, which shows billows across southeast MO and western portions of southern IL. ..Mosier.. 04/20/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PAH...ILX...LSX...SGF... LAT...LON 36559334 37589278 38689217 40009114 40249033 39998857 38358923 36749108 36559334 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Thu Apr 20 2023 Valid 202000Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND EVENING IN A CORRIDOR FROM SOUTHERN WISCONSIN THROUGH THE MIDDLE MISSISSIPPI VALLEY AND SOUTHEASTERN GREAT PLAINS... ...SUMMARY... Scattered severe thunderstorms remain possible late this afternoon and evening in a corridor from from southern Wisconsin to south Texas. Damaging winds and large hail appear the primary hazards in terms of coverage, but a few tornadoes are also possible. ...20Z Update... Large-scale mid-level troughing now east of the Rockies may amplify a bit further, but only a slow eastward progression into the Mississippi Valley is expected through early Friday. An associated modestly deep cyclone appears likely to continue to gradually occlude across the Upper Midwest and adjacent Great Lakes vicinity, with the trailing cold front advancing into the lower Great Lakes, lower Ohio, Mississippi and Rio Grande Valleys. Due to the lingering presence of mid-level troughing across the Florida Peninsula, and dry/potentially cool boundary-layer air associated with surface ridging across much of the Southeast and eastern Gulf of Mexico, low-level moisture return to the warm sector of the cyclone remains rather modest. Seasonably moist boundary-layer air remains largely confined to southern/central and eastern Texas, where south through southwesterly flow in the lower/mid troposphere has become modest to weak, in the wake of the cyclone. As a result, while conditions have become conducive to increasing vigorous thunderstorm development posing at least some risk for large hail, damaging wind gusts and tornadoes, in a pre-frontal corridor from Texas through southern Wisconsin, severe weather potential overall does not appear particularly optimized. Severe probabilities are being maintained as outlined in the 1630Z, aside from some change to account for the progression of the synoptic features. ..Kerr.. 04/20/2023 .PREV DISCUSSION... /ISSUED 1126 AM CDT Thu Apr 20 2023/ ...Mid-MS Valley to southern WI... Elevated convection persists across portions of southern WI and IL, but appears to be weakening. Subsidence in its wake has yielded cloud breaks immediately ahead of the primary surface cyclone over central IA, which will yield destabilization into this afternoon across the Mid-MS Valley and IL to southern WI. The cyclone will initially track northeast into western WI before occluding northward, aided by an 80-90 kt 500-mb jetlet curling across IA into central WI. The degree of surface-based destabilization remains somewhat uncertain with a confined warm/moist sector ahead of the eastward-moving cold front. But guidance is largely insistent that a narrow plume of moderate MLCAPE of 1000-1500 J/kg should develop, as upper 50s to low 60s surface dew points in eastern IA and northeast MO advect northeast. The synoptic pattern will support strong effective bulk shear along with an enlarged low-level hodograph favorable for discrete supercells consolidating into small clusters. As such, have increased tornado probabilities and expanded the cat 2-SLGT risk northward. Otherwise, a mix of scattered large hail and damaging wind will be possible, but the overall threat will likely be spatially and temporally confined given the narrow warm/moist sector, resulting in severe potential rapidly weakening in the early evening roughly east of the IL/IN border longitude. ...Central/east TX to AR... The cold front surging south-southeast towards the Concho Valley of west-central TX and the Ozark Plateau is expected to help focus scattered to widespread thunderstorms along and ahead of it this afternoon and evening. Large buoyancy with MLCAPE in excess of 2500 J/kg, supported by steep mid-level lapse rates, will primarily reside across central to south TX where low-level shear should remain weak. But sufficient deep-layer shear, although somewhat parallel to the front, should support initial supercells consolidating into several clusters and one or more MCSs. Farther northeast across the Ark-LA-Tex into AR, low-level shear will be comparatively greater but buoyancy will be relatively less. Large hail can be expected with the more discrete storms (some in excess of 2 inch diameter, especially across central to south TX), and the potential for damaging winds will increase with upscale growth this evening. The tornado threat is expected to remain unfocused and short-lived, likely dependent on favorable storm-scale/boundary interactions. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0231 PM CDT Thu Apr 20 2023 Valid 202000Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND EVENING IN A CORRIDOR FROM SOUTHERN WISCONSIN THROUGH THE MIDDLE MISSISSIPPI VALLEY AND SOUTHEASTERN GREAT PLAINS... ...SUMMARY... Scattered severe thunderstorms remain possible late this afternoon and evening in a corridor from from southern Wisconsin to south Texas. Damaging winds and large hail appear the primary hazards in terms of coverage, but a few tornadoes are also possible. ...20Z Update... Large-scale mid-level troughing now east of the Rockies may amplify a bit further, but only a slow eastward progression into the Mississippi Valley is expected through early Friday. An associated modestly deep cyclone appears likely to continue to gradually occlude across the Upper Midwest and adjacent Great Lakes vicinity, with the trailing cold front advancing into the lower Great Lakes, lower Ohio, Mississippi and Rio Grande Valleys. Due to the lingering presence of mid-level troughing across the Florida Peninsula, and dry/potentially cool boundary-layer air associated with surface ridging across much of the Southeast and eastern Gulf of Mexico, low-level moisture return to the warm sector of the cyclone remains rather modest. Seasonably moist boundary-layer air remains largely confined to southern/central and eastern Texas, where south through southwesterly flow in the lower/mid troposphere has become modest to weak, in the wake of the cyclone. As a result, while conditions have become conducive to increasing vigorous thunderstorm development posing at least some risk for large hail, damaging wind gusts and tornadoes, in a pre-frontal corridor from Texas through southern Wisconsin, severe weather potential overall does not appear particularly optimized. Severe probabilities are being maintained as outlined in the 1630Z, aside from some change to account for the progression of the synoptic features. ..Kerr.. 04/20/2023 .PREV DISCUSSION... /ISSUED 1126 AM CDT Thu Apr 20 2023/ ...Mid-MS Valley to southern WI... Elevated convection persists across portions of southern WI and IL, but appears to be weakening. Subsidence in its wake has yielded cloud breaks immediately ahead of the primary surface cyclone over central IA, which will yield destabilization into this afternoon across the Mid-MS Valley and IL to southern WI. The cyclone will initially track northeast into western WI before occluding northward, aided by an 80-90 kt 500-mb jetlet curling across IA into central WI. The degree of surface-based destabilization remains somewhat uncertain with a confined warm/moist sector ahead of the eastward-moving cold front. But guidance is largely insistent that a narrow plume of moderate MLCAPE of 1000-1500 J/kg should develop, as upper 50s to low 60s surface dew points in eastern IA and northeast MO advect northeast. The synoptic pattern will support strong effective bulk shear along with an enlarged low-level hodograph favorable for discrete supercells consolidating into small clusters. As such, have increased tornado probabilities and expanded the cat 2-SLGT risk northward. Otherwise, a mix of scattered large hail and damaging wind will be possible, but the overall threat will likely be spatially and temporally confined given the narrow warm/moist sector, resulting in severe potential rapidly weakening in the early evening roughly east of the IL/IN border longitude. ...Central/east TX to AR... The cold front surging south-southeast towards the Concho Valley of west-central TX and the Ozark Plateau is expected to help focus scattered to widespread thunderstorms along and ahead of it this afternoon and evening. Large buoyancy with MLCAPE in excess of 2500 J/kg, supported by steep mid-level lapse rates, will primarily reside across central to south TX where low-level shear should remain weak. But sufficient deep-layer shear, although somewhat parallel to the front, should support initial supercells consolidating into several clusters and one or more MCSs. Farther northeast across the Ark-LA-Tex into AR, low-level shear will be comparatively greater but buoyancy will be relatively less. Large hail can be expected with the more discrete storms (some in excess of 2 inch diameter, especially across central to south TX), and the potential for damaging winds will increase with upscale growth this evening. The tornado threat is expected to remain unfocused and short-lived, likely dependent on favorable storm-scale/boundary interactions. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0208 PM CDT Thu Apr 20 2023 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN NEW MEXICO... ...portions of the central Plains... Confidence has increased that dry and windy conditions in the post-frontal air mass across the central Plains will be significant enough to support at least a few hours of elevated fire-weather conditions from eastern CO, into southwestern KS. Wind gusts of 15-20 mph and RH values of 20-25% will be possible over areas with very receptive fuels. Otherwise the previous forecast remains valid with minimal changes. ..Lyons.. 04/20/2023 .PREV DISCUSSION... /ISSUED 1259 AM CDT Thu Apr 20 2023/ ...Synopsis... Strong northwesterly mid-level flow will persist across the Southwest on Friday which, when combined with deep mixing in the region will lead to strong surface winds. These winds will be further enhanced across east-central New Mexico as a weak surface low develops in the Texas Panhandle. This will result in a strengthening surface pressure gradient and a localized region of critical fire weather conditions across east central New Mexico. Some elevated fire weather conditions may develop across southern Kansas and northwest Oklahoma, but it appears these conditions should be too brief to warrant expansion of the Elevated delineation at this time. However, trends will continue to be monitored and an expansion into this region may be needed at a later time. ...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 0208 PM CDT Thu Apr 20 2023 Valid 211200Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHERN NEW MEXICO... ...portions of the central Plains... Confidence has increased that dry and windy conditions in the post-frontal air mass across the central Plains will be significant enough to support at least a few hours of elevated fire-weather conditions from eastern CO, into southwestern KS. Wind gusts of 15-20 mph and RH values of 20-25% will be possible over areas with very receptive fuels. Otherwise the previous forecast remains valid with minimal changes. ..Lyons.. 04/20/2023 .PREV DISCUSSION... /ISSUED 1259 AM CDT Thu Apr 20 2023/ ...Synopsis... Strong northwesterly mid-level flow will persist across the Southwest on Friday which, when combined with deep mixing in the region will lead to strong surface winds. These winds will be further enhanced across east-central New Mexico as a weak surface low develops in the Texas Panhandle. This will result in a strengthening surface pressure gradient and a localized region of critical fire weather conditions across east central New Mexico. Some elevated fire weather conditions may develop across southern Kansas and northwest Oklahoma, but it appears these conditions should be too brief to warrant expansion of the Elevated delineation at this time. However, trends will continue to be monitored and an expansion into this region may be needed at a later time. ...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 1225 PM CDT Thu Apr 20 2023 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY INTO FRIDAY EVENING ACROSS PARTS OF THE UPPER OHIO VALLEY INTO LOWER GREAT LAKES...AND ACROSS PARTS OF THE UPPER TEXAS COAST INTO LOWER MISSISSIPPI VALLEY... ...SUMMARY... Strong thunderstorms on Friday may impact parts of the upper Ohio Valley into lower Great Lakes region, and the upper Texas coastal plain into lower Mississippi Valley, accompanied by at least some risk for severe weather. ...Synopsis... Models indicate that a more prominent blocking regime will continue to evolve across eastern North America into the northwestern Atlantic through this period and beyond. As a result, it appears that amplified mid-level troughing across the Great Plains and Mississippi Valley early Friday will make only slow further eastward progression across and east of the Mississippi Valley through early Saturday. The center of an associated broad, modestly deep and occluding surface cyclone is forecast to gradually weaken across the Upper Midwest into adjacent Great Lakes region. However, it is possible that similar secondary surface cyclogenesis may commence by late Friday night across the Allegheny Plateau vicinity, as a couple of short wave perturbations pivot around a lingering mid-level cyclonic circulation across the Upper Midwest. An initial surface cold front advancing eastward through the Ohio Valley during the day Friday may provide the focus for the developing surface low. It appears that the trailing flank of the this front may slow and weaken across the lower Mississippi Valley through lower Rio Grande Valley vicinity, while a reinforcing cold intrusion makes progress through the lower Ohio/middle Mississippi Valleys and central Great Plains. At the same time, dry/potentially cool air, associated with surface ridging shifting off the south Atlantic coast, may be slow to lose influence across much of the Southeast. ...Upper Ohio Valley into lower Great Lakes vicinity... Pre-frontal boundary-layer moistening appears likely to remain rather modest. However, models suggest that a narrow corridor of stronger daytime boundary-layer heating and mixing will become sufficiently unstable to support at least scattered afternoon thunderstorm development, aided by favorable forcing for ascent downstream of the approaching large-scale mid-level trough axis. Based on forecast soundings the risk for severe hail appears negligible, but downward mixing of 30-50+ kt south-southwesterly flow (within the 850-500 mb layer) in convective downdrafts may contribute to at least some potential for damaging wind gusts into early Friday evening. ...Upper Texas coastal plain into lower Mississippi Valley... It appears that fairly extensive, but weakening, pre-frontal thunderstorm activity may be ongoing at 12Z Friday across parts of the lower Mississippi Valley into areas near or offshore of upper Texas coastal areas, in the presence of modest and/or weakening southerly lower/mid-tropospheric flow. With the Southeastern surface ridging also slow to lose influence, the extent of any subsequent severe weather potential for Friday remains unclear. Mid-level forcing for ascent associated with a notable short wave impulse forecast to pivot east-northeast of the southern Great Plains Red River Valley may be mostly glancing. However, with sufficient boundary-layer heating and destabilization, a pre-frontal corridor of strong to severe thunderstorm development appears possible Friday afternoon and evening, beneath strengthening westerly mid-level flow (50-70+ kt around 500 mb). This may include supercells posing a risk for large hail and some potential for a tornado. Due to lingering uncertainties, severe weather probabilities are currently being maintained at 5 percent. However, it is possible that probabilities could still be increased in later outlooks for this period, particularly across parts of central/northern Louisiana into central Mississippi. ..Kerr.. 04/20/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1225 PM CDT Thu Apr 20 2023 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FRIDAY INTO FRIDAY EVENING ACROSS PARTS OF THE UPPER OHIO VALLEY INTO LOWER GREAT LAKES...AND ACROSS PARTS OF THE UPPER TEXAS COAST INTO LOWER MISSISSIPPI VALLEY... ...SUMMARY... Strong thunderstorms on Friday may impact parts of the upper Ohio Valley into lower Great Lakes region, and the upper Texas coastal plain into lower Mississippi Valley, accompanied by at least some risk for severe weather. ...Synopsis... Models indicate that a more prominent blocking regime will continue to evolve across eastern North America into the northwestern Atlantic through this period and beyond. As a result, it appears that amplified mid-level troughing across the Great Plains and Mississippi Valley early Friday will make only slow further eastward progression across and east of the Mississippi Valley through early Saturday. The center of an associated broad, modestly deep and occluding surface cyclone is forecast to gradually weaken across the Upper Midwest into adjacent Great Lakes region. However, it is possible that similar secondary surface cyclogenesis may commence by late Friday night across the Allegheny Plateau vicinity, as a couple of short wave perturbations pivot around a lingering mid-level cyclonic circulation across the Upper Midwest. An initial surface cold front advancing eastward through the Ohio Valley during the day Friday may provide the focus for the developing surface low. It appears that the trailing flank of the this front may slow and weaken across the lower Mississippi Valley through lower Rio Grande Valley vicinity, while a reinforcing cold intrusion makes progress through the lower Ohio/middle Mississippi Valleys and central Great Plains. At the same time, dry/potentially cool air, associated with surface ridging shifting off the south Atlantic coast, may be slow to lose influence across much of the Southeast. ...Upper Ohio Valley into lower Great Lakes vicinity... Pre-frontal boundary-layer moistening appears likely to remain rather modest. However, models suggest that a narrow corridor of stronger daytime boundary-layer heating and mixing will become sufficiently unstable to support at least scattered afternoon thunderstorm development, aided by favorable forcing for ascent downstream of the approaching large-scale mid-level trough axis. Based on forecast soundings the risk for severe hail appears negligible, but downward mixing of 30-50+ kt south-southwesterly flow (within the 850-500 mb layer) in convective downdrafts may contribute to at least some potential for damaging wind gusts into early Friday evening. ...Upper Texas coastal plain into lower Mississippi Valley... It appears that fairly extensive, but weakening, pre-frontal thunderstorm activity may be ongoing at 12Z Friday across parts of the lower Mississippi Valley into areas near or offshore of upper Texas coastal areas, in the presence of modest and/or weakening southerly lower/mid-tropospheric flow. With the Southeastern surface ridging also slow to lose influence, the extent of any subsequent severe weather potential for Friday remains unclear. Mid-level forcing for ascent associated with a notable short wave impulse forecast to pivot east-northeast of the southern Great Plains Red River Valley may be mostly glancing. However, with sufficient boundary-layer heating and destabilization, a pre-frontal corridor of strong to severe thunderstorm development appears possible Friday afternoon and evening, beneath strengthening westerly mid-level flow (50-70+ kt around 500 mb). This may include supercells posing a risk for large hail and some potential for a tornado. Due to lingering uncertainties, severe weather probabilities are currently being maintained at 5 percent. However, it is possible that probabilities could still be increased in later outlooks for this period, particularly across parts of central/northern Louisiana into central Mississippi. ..Kerr.. 04/20/2023 Read more

MD 0561 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF SOUTHWESTERN AND SOUTH-CENTRAL OKLAHOMA
Mesoscale Discussion 0561 NWS Storm Prediction Center Norman OK 0357 PM CDT Wed Apr 19 2023 Areas affected...Portions of southwestern and south-central Oklahoma Concerning...Severe potential...Watch possible Valid 192057Z - 192300Z Probability of Watch Issuance...60 percent SUMMARY...Conditional severe threat increasing. Potential for supercells with large hail and a couple tornadoes late afternoon into the evening. A watch will be possible in the next few hours. DISCUSSION...A conditional severe threat is increasing across portions of southwestern and south-central Oklahoma. A surface dryline continues to mix eastward across Oklahoma and Texas. Ahead of the dryline, mid 60s dew points have moved north of the Red River across southern Oklahoma. 19z RAOB from OUN indicates moistening and a weakening cap beneath an elevated mixed layer with steep lapse rates (around 8 C/km). Temperatures have warmed into the 80s with strong daytime heating, with MLCAPE around 2500-3000 J/kg. Further indication of the weakening cap can be seen in satellite, as cumulus fields continue to show increasing development. The 19z OUN RAOB and surface objective analysis also indicate deep layer shear around 35-40 kts. The main risk with any initial storm development would be large hail, given steep lapse rates. As the main wave approaches from the west with deepening low pressure across the Central Plains, 850 mb flow will increase through the evening, further elongating hodographs and increasing risk of a couple tornadoes. Trends will be monitored closely with a watch will be possible within few hours. ..Thornton/Grams.. 04/19/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FWD...OUN... LAT...LON 34169733 33999757 33929774 33909784 33949796 34139818 34159835 34089846 34129855 34299871 34439874 34669876 35169828 35299807 35399786 35499766 35529759 35589739 35519695 35349683 35099688 34989692 34669705 34509713 34239726 34169733 Read more

WW 0146 Status Updates
STATUS FOR WATCH 0146 HAS NOT BEEN ISSUED YET Read more

WW 146 SEVERE TSTM IA MN 192050Z - 200400Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 146 NWS Storm Prediction Center Norman OK 350 PM CDT Wed Apr 19 2023 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest to north-central Iowa Far southwest Minnesota * Effective this Wednesday afternoon and evening from 350 PM until 1100 PM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 60 mph possible A tornado or two possible SUMMARY...A supercell cluster should develop northeast from the Mid-Missouri Valley and pose a primary threat of large hail north of the surface warm front. The severe thunderstorm watch area is approximately along and 45 statute miles north and south of a line from 50 miles west southwest of Worthington MN to 30 miles northeast of Fort Dodge IA. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 50 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 23030. ...Grams Read more