janetjanet998

a few of the storms in east AL now trying to hook

SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE JACKSON MS 710 PM CDT SUN APR 19 2020 MSC073-091-200100- /O.CON.KJAN.TO.W.0043.000000T0000Z-200420T0100Z/ MARION MS-LAMAR MS- 710 PM CDT SUN APR 19 2020 ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 800 PM CDT FOR MARION AND LAMAR COUNTIES... AT 709 PM CDT, A LARGE AND EXTREMELY DANGEROUS TORNADO WAS LOCATED OVER DEXTER, OR 7 MILES SOUTH OF KOKOMO, MOVING EAST AT 50 MPH. THIS IS A PARTICULARLY DANGEROUS SITUATION. TAKE COVER NOW! HAZARD...DAMAGING TORNADO. SOURCE...RADAR INDICATED ROTATION.

00z and only 2 tornado reports so far (plus whatever that brief TDS was in LA)

SPC talks about that outflow boundary i mentioned messing things up for the northern cells but is eyeing the southern one CUS11 KWNS 192338 SWOMCD SPC MCD 192337 MSZ000-LAZ000-200030- MESOSCALE DISCUSSION 0412 NWS STORM PREDICTION CENTER NORMAN OK 0637 PM CDT SUN APR 19 2020 AREAS AFFECTED...FAR SOUTHERN MISSISSIPPI INTO EASTERN LOUISIANA CONCERNING...TORNADO WATCH 121...122...123... VALID 192337Z - 200030Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 121, 122, 123 CONTINUES. SUMMARY...A CORRIDOR FOR HIGHER TORNADO POTENTIAL EXISTS ACROSS FAR SOUTHERN MISSISSIPPI INTO ADJACENT AREAS OF EASTERN LOUISIANA SOUTH OF AN OUTFLOW BOUNDARY. STORMS MOVING ALONG/SOUTH OF THIS BOUNDARY WILL ENCOUNTER STRONGER LOW-LEVEL SHEAR. DISCUSSION...AN OUTFLOW BOUNDARY HAS MOVED SOUTH FROM CENTRAL MISSISSIPPI INTO SOUTHERN MISSISSIPPI WHERE WINDS HAVE BACKED TO SOUTHEASTERLY ALONG AND JUST SOUTH OF THIS BOUNDARY. A FEW SUPERCELLS DEVELOPED ACROSS SOUTHWEST MISSISSIPPI AND EASTERN LOUISIANA IN THE LAST HOUR OR SO, BUT HAVE NOW MOSTLY CONGEALED INTO A CLUSTER DUE TO UPSCALE GROWTH AND THE SOUTHWARD MOVING OUTFLOW BOUNDARY. HOWEVER, THE SOUTHERN STORM IS STILL EXHIBITING SUPERCELL CHARACTERISTICS AND HAS SHOWN MESH VALUES OF 1+ INCH ALTHOUGH CONVECTIVE INTERFERENCE HAS WEAKENED IT SOMEWHAT. SURFACE WINDS NEAR MCB AND EASTWARD HAVE BACKED TO THE SOUTHEAST INDICATING POTENTIALLY HIGHER LOW-LEVEL HELICITY, WHICH COULD INCREASE THE TORNADO THREAT. THERE REMAINS UNCERTAINTY DUE TO THE AMOUNT OF POTENTIAL CONVECTIVE INTERFERENCE AND THAT THE OUTFLOW BOUNDARY COULD CONTINUE SLIDING SOUTHWARD.

the shallow backdoor outflows have really squeezed the warm sector south...I still think the lack of strong surface flow pushing back on the outflows allowed this HRRR says the warrm sector never makes it to SC expect perhaps the extreme SE coast

MESOSCALE DISCUSSION 0411 NWS STORM PREDICTION CENTER NORMAN OK 0552 PM CDT SUN APR 19 2020 AREAS AFFECTED...PORTIONS OF CENTRAL/SOUTHERN ALABAMA CONCERNING...TORNADO WATCH 123... VALID 192252Z - 200015Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 123 CONTINUES. SUMMARY...TORNADO THREAT CONTINUES ACROSS THE SOUTHERN TWO-THIRDS OF WW123. DISCUSSION...EARLY-DAY CONVECTION THAT SPREAD ACROSS GA HAS FORCED A WELL-DEFINED BOUNDARY SOUTH AND A BIT WEST ARCING ACROSS WW123. LATEST SURFACE OBS SUGGEST THIS WIND SHIFT EXTENDS FROM HENRY - BUTLER - MARENGO COUNTIES IN AL, IMMEDIATELY AHEAD OF A SURGING SQUALL LINE. OVER THE LAST FEW HOURS AN MCV HAS EVOLVED ALONG THE NORTHERN EDGE OF A PRONOUNCED SQUALL LINE THAT IS SURGING EAST IN EXCESS OF 45KT. THUNDERSTORMS HAVE STRUGGLED TO DEVELOP ACROSS THE WARM SECTOR, POSSIBLY DUE TO SOMEWHAT WEAK LOW-LEVEL CONVERGENCE. WHILE THE AIR MASS HAS WARMED ACROSS SOUTHERN MS INTO SOUTHERN AL, THE PRIMARY CONCERN IN THE NEAR-TERN WILL BE ALONG THE AFOREMENTIONED BOUNDARY WHICH SHOULD SERVE AS THE FOCUS FOR UPSTREAM CONVECTION TO PROPAGATE ALONG. WHILE THE PRIMARY STORM MODE REMAINS LINEAR WITH CLUSTERS, STRONG SHEAR CONTINUES TO SUPPORT SUPERCELLS; ALTHOUGH, THE MOST LIKELY REGION FOR SUPERCELLS WILL BE ACROSS THE WARM SECTOR WHERE STORMS HAVE STRUGGLED TO DEVELOP. ..DARROW.. 04/19/2020

MESOSCALE DISCUSSION 0410 NWS STORM PREDICTION CENTER NORMAN OK 0540 PM CDT SUN APR 19 2020 AREAS AFFECTED...CENTRAL/SOUTHERN LOUISIANA AND SOUTHWEST MISSISSIPPI CONCERNING...TORNADO WATCH 121...122... VALID 192240Z - 200045Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 121, 122 CONTINUES. SUMMARY...THE SEVERE THREAT CONTINUES ACROSS THE LOWER MISSISSIPPI VALLEY. A SQUALL LINE IS BECOMING MORE WELL DEFINED WITH DAMAGING WINDS AND TORNADOES EMBEDDED WITHIN THE LINE AS THE MAIN THREATS. DISCUSSION...A SQUALL LINE CONTINUES TO MOVE EASTWARD ACROSS THE LOWER MISSISSIPPI VALLEY WITH A COLLOCATED MESOLOW. STRONG DEEP-LAYER MOSTLY SOUTHWESTERLY FLOW RESULTING IN 50+ KNOTS OF EFFECTIVE BULK SHEAR AND MLCAPE OF 2500+ J/KG PER ARE DEVELOPING AND MAINTAINING DEEP, ORGANIZED CONVECTION. THE LINE IS ORIENTED MOSTLY SOUTHWEST-NORTHEAST, BUT IT HAS SHOWN EVIDENCE OF SEGMENTS BECOMING MORE NORTH-SOUTH ORIENTED, WHICH WOULD CREATE MORE PERPENDICULAR FLOW AND INCREASE THE DAMAGING WIND AND TORNADO THREAT. MESOVORTICES HAVE BEEN OBSERVED IN SOME OF THESE MORE NORTH-SOUTH SEGMENTS WITH TORNADO POTENTIAL HIGHEST NEAR THE MESOLOW IN OTHERWISE VEERED SURFACE FLOW. THESE STORMS ARE LIKELY TO CONTINUE MOVING EASTERLY THROUGH THE EVENING WITH INTENSIFICATION POSSIBLE AS THE LOW-LEVEL JET INCREASES.

two mini hooking cells over SE GA both T-storm warned tagged tornado possible but they are just north of an outflow boundary the 2nd one may be trying to suck the boundary back in

just like further east...another surface based storm killer outflow boundary is sagging south over Southern MS per JAN radar in wake of the complex over the MS/AL state line semi discrete storms west of it but the northern 1/2 of those will move north of the boundary , a couple may interact with it and spin up but must turn right to stay in the more unstable air edit: 3 cells may stay along or just south of this boundary if they move due east

this seems to be happening with a sagging shallow SW moving outflow over GA now almost to the extreme NE FL panhandle seen on KEOX elevated junk develops over and north it in the LLJ winds still veered in warm sector and storm motion would take any warm sector storm north of the boundary quickly unless they turn right like a couple storms are trying to do in east MS

DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0300 PM CDT SUN APR 19 2020 VALID 192000Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF LA INTO SOUTHERN/CENTRAL MS/AL/GA... ..SUMMARY A SEVERE-WEATHER OUTBREAK IS EXPECTED ACROSS MUCH OF THE DEEP SOUTH THROUGH TONIGHT, WITH THE GREATEST THREAT FROM EAST TEXAS AND THE DELTA REGION EASTWARD ACROSS PARTS OF MISSISSIPPI, ALABAMA, AND GEORGIA. MULTIPLE EPISODES OF THUNDERSTORMS WILL LIKELY RESULT IN SEVERAL TORNADOES (SOME STRONG), WIDESPREAD DAMAGING WINDS, AND LARGE HAIL. ..20Z UPDATE PRIMARY CHANGE WITH THIS UPDATE WAS TO MAKE ADJUSTMENTS TO THE WESTERN EDGE OF HIGHER SEVERE PROBABILITIES ACROSS PARTS OF EAST TX INTO LA BASED ON ONGOING STORMS. THE MOST FAVORED CORRIDOR FOR ALL SEVERE HAZARDS THROUGH THIS AFTERNOON WILL REMAIN ALONG/SOUTH OF A CONVECTIVELY REINFORCED WARM FRONT EXTENDING FROM EAST TX INTO CENTRAL LA/MS AND PARTS OF SOUTHERN/CENTRAL AL. 18Z SOUNDINGS FROM LCH AND LIX SHOW STRONG LOW-LEVEL FLOW, BUT A WEAKNESS IN THE MID-LEVELS ROUGHLY IN THE 750-600 MB LAYER. THIS WEAKNESS IS FORECAST TO DIMINISH THIS AFTERNOON AS THE SHORTWAVE TROUGH OVER THE SOUTHERN PLAINS CONTINUES TO SHIFT EASTWARD TOWARDS THE LOWER MS VALLEY THIS EVENING. A FAVORABLE CORRIDOR FOR STRONG TORNADOES IS STILL APPARENT ALONG/SOUTH OF THE WARM FRONT ACROSS PARTS OF CENTRAL LA INTO SOUTHERN/CENTRAL MS/AL/GA. BOTH STRONG INSTABILITY AND SHEAR WILL BE PRESENT ACROSS THESE AREAS FROM THIS AFTERNOON THROUGH THE OVERNIGHT HOURS AS A SOUTHWESTERLY LOW-LEVEL JET AND CORRESPONDING LOW-LEVEL SHEAR BOTH STRENGTHEN. AN OUTFLOW BOUNDARY FROM EARLIER STORMS DRAPED ACROSS PARTS OF SOUTHERN MS/AL MAY ALSO BE A FOCUS FOR GREATER TORNADO POTENTIAL GIVEN LOCALLY BACKED LOW-LEVEL FLOW.

SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 210 PM CDT SUN APR 19 2020 TXC039-191930- /O.CON.KHGX.TO.W.0007.000000T0000Z-200419T1930Z/ BRAZORIA TX- 210 PM CDT SUN APR 19 2020 ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 230 PM CDT FOR WEST CENTRAL BRAZORIA COUNTY... AT 209 PM CDT, SPOTTERS REPORTED A CONFIRMED TORNADO LOCATED WEST OF WEST COLUMBIA, MOVING EAST AT 30 MPH. HAZARD...DAMAGING TORNADO AND HALF DOLLAR SIZE HAIL. SOURCE...WEATHER SPOTTERS CONFIRMED TORNADO.

like last weekend clues the cell in western north central LA is sharping up on the back side out of the grunge edit: now TOR wanred

so far surface winds remain veered SW and light this favors outflow dominated MCS..with meso head spin ups HRRR seems to continue the trend edit: surface winds do pick up some here soon

ULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE HOUSTON/GALVESTON TX 1228 PM CDT SUN APR 19 2020 THE NATIONAL WEATHER SERVICE IN LEAGUE CITY HAS ISSUED A * TORNADO WARNING FOR... SOUTHEASTERN SAN JACINTO COUNTY IN SOUTHEASTERN TEXAS... SOUTHEASTERN POLK COUNTY IN SOUTHEASTERN TEXAS... * UNTIL 115 PM CDT. * AT 1227 PM CDT, A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO WAS LOCATED OVER SHEPHERD, OR 9 MILES NORTH OF CLEVELAND, MOVING NORTHEAST AT 35 MPH. HAZARD...TORNADO. SOURCE...RADAR INDICATED ROTATION. IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE TO ROOFS, WINDOWS, AND VEHICLES WILL OCCUR. TREE DAMAGE IS LIKELY.

BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE CHARLESTON SC 123 PM EDT SUN APR 19 2020 THE NATIONAL WEATHER SERVICE IN CHARLESTON HAS ISSUED A * TORNADO WARNING FOR PORTIONS OF... BRYAN COUNTY IN SOUTHEASTERN GEORGIA... EVANS COUNTY IN SOUTHEASTERN GEORGIA... BULLOCH COUNTY IN SOUTHEASTERN GEORGIA... * UNTIL 200 PM EDT. * AT 123 PM EDT, A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO WAS LOCATED NEAR NEVILS, MOVING EAST AT 50 MPH. HAZARD...TORNADO. SOURCE...RADAR INDICATED ROTATION.

URGENT - IMMEDIATE BROADCAST REQUESTED TORNADO WATCH NUMBER 121 NWS STORM PREDICTION CENTER NORMAN OK 1145 AM CDT SUN APR 19 2020 THE NWS STORM PREDICTION CENTER HAS ISSUED A * TORNADO WATCH FOR PORTIONS OF NORTHEAST LOUISIANA CENTRAL AND SOUTHERN MISSISSIPPI * EFFECTIVE THIS SUNDAY MORNING AND EVENING FROM 1145 AM UNTIL 700 PM CDT. * PRIMARY THREATS INCLUDE... SEVERAL TORNADOES AND A COUPLE INTENSE TORNADOES LIKELY WIDESPREAD LARGE HAIL AND SCATTERED VERY LARGE HAIL EVENTS TO 2.5 INCHES IN DIAMETER LIKELY WIDESPREAD DAMAGING WIND GUSTS TO 70 MPH LIKELY SUMMARY...CLUSTERS OF THUNDERSTORMS OVER LOUISIANA WILL TRACK EASTWARD ACROSS THE WATCH AREA THIS AFTERNOON. THE STRONGEST STORMS WILL POSE A RISK LARGE HAIL, DAMAGING WINDS, AND TORNADOES. AN ISOLATED STRONG TORNADO IS POSSIBLE.

VAD out of Houston showing an increase in winds aloft the past hour

storms developing within the warm sector on an outflow boundary over SE AL and SW GA , within the warm sector they look linear for now but something to keep an eye on edit: these appear to be north of an outlfow boundary seen moving south on EOX

DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1105 AM CDT SUN APR 19 2020 VALID 191630Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS EXTENDING FROM PARTS OF LOUISIANA INTO MISSISSIPPI...ALABAMA...AND GEORGIA... ..SUMMARY A SEVERE-WEATHER OUTBREAK IS EXPECTED ACROSS MUCH OF THE DEEP SOUTH THROUGH TONIGHT, WITH THE GREATEST THREAT FROM EAST TEXAS AND THE DELTA REGION EASTWARD ACROSS PARTS OF ALABAMA AND GEORGIA. MULTIPLE EPISODES OF THUNDERSTORMS WILL RESULT IN TORNADOES (SOME STRONG), DAMAGING WIND AND LARGE HAIL. ..TX/LA/MS/AL SEVERAL LARGE CLUSTERS OF INTENSE THUNDERSTORMS HAVE DEVELOPED THIS MORNING OVER EAST TX AND WESTERN LA. THESE STORMS ARE IN A REGION OF INCREASING LARGE-SCALE LIFT AHEAD OF THE AN APPROACHING SHORTWAVE TROUGH. VERY STEEP MIDLEVEL LAPSE RATES AND AMPLE CAPE, ALONG WITH DEEP-LAYER SHEAR SUFFICIENT FOR ROTATING STORMS, WILL PROMOTE THE POTENTIAL FOR LARGE HAIL AND DAMAGING WINDS IN THE STRONGER CELLS. LOCAL VAD PROFILES ALSO SHOW SUFFICIENT LOW-LEVEL SHEAR FOR A RISK OF A FEW TORNADES - ESPECIALLY THIS AFTERNOON AS LOW-LEVEL JET STRENGTHENS. A WELL-DEFINED WARM FRONT EXTENDS FROM CENTRAL LA EASTWARD INTO MS/AL. CLUSTERS OF STORMS WILL TRACK ALONG AND SOUTH OF THE WARM FRONT THIS AFTERNOON AND EVENING. FORECAST SOUNDINGS SHOW PARAMETERS FAVORABLE FOR ALL MODES OF SEVERE. HODOGRAPHS WILL BECOME QUITE LARGE THROUGH THE DAY, SUPPORTIVE OF STRONG TORNADOES IN THE MORE DISCRETE SUPERCELLS THAT MAY FORM. A FEW OF THE CLUSTERS MAY ALSO DEVELOP INTO FAST-MOVING BOWING STRUCTURES CAPABLE OF LOCALLY DAMAGING WIND GUSTS. IT APPEARS LIKELY THAT THE CORRIDOR ALONG AND SOUTH OF THE WARM FRONT (WITHIN THE MDT RISK) MAY SEE SEVERAL ROUNDS OF STRONG/SEVERE CONVECTION THIS AFTERNOON INTO TONIGHT. ..AL/GA/SC A LARGE SHIELD OF ONGOING SHOWERS AND THUNDERSTORMS IS AFFECTING PARTS AL/GA/SC TODAY. THE AFOREMENTIONED WARM FRONT IS BUILDING NORTHWARD, AND IS NEARING THE SOUTHERN FRINGES OF THE CONVECTION. ONCE THAT OCCURS, SURFACE-BASED PARCELS WILL BE REALIZED BY THE STORMS AND THE RISK OF SEVERE WEATHER SHOULD INCREASE. DAMAGING WINDS AND HAIL WILL BE POSSIBLE, BUT THE PROXIMITY OF THE WARM FRONT AND STRENGTHENING LOW-LEVEL SHEAR/HELICITY THIS AFTERNOON WILL ALSO SUPPORT A RISK OF TORNADOES. LATER TONIGHT, STORMS OVER MS/AL WILL TRACK EASTWARD AND ALSO AFFECT THIS REGION. PARAMETERS WILL REMAIN QUITE STRONG THROUGH THE OVERNIGHT PERIOD, WITH A CONSIDERABLE RISK OF BOWING STRUCTURES CAPABLE OF DAMAGING WINDS, AND THE THREAT OF SUPERCELL STORMS PRODUCING TORNADOES (SOME STRONG).

It will be a NOWCAST thing of course you will have to wait until the low strengthens late tonight and pushes the front north NAM nest finally gets the moisture into the area around 12z just in time

it looks like outlfows keep the best moisture south... some models have two warm fronts...the one with the best moisture remains south until very late if the model radar is correct then pattern recognition is for training outflow dominated sagging storms along the warm front with flooding and wind threats the exceptions may be early over east Texas and in to LA before they form a blob and late tonight over GA time will tell

DAY 1 CONVECTIVE OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 0749 AM CDT SUN APR 19 2020 VALID 191300Z - 201200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FROM THE TEXAS/LOUISIANA BORDER AREA TO SOUTHEASTERN GEORGIA... ..SUMMARY A SEVERE-WEATHER OUTBREAK IS EXPECTED ACROSS MUCH OF THE DEEP SOUTH THROUGH TONIGHT, WITH THE GREATEST THREAT FROM SOME OF EAST TEXAS AND THE DELTA REGION EASTWARD OVER PARTS OF ALABAMA AND GEORGIA. MULTIPLE EPISODES OF THUNDERSTORMS WILL RESULT IN TORNADOES (SOME STRONG), DAMAGING WIND AND LARGE HAIL. --- TECHNICAL DISCUSSION --- ..SYNOPSIS IN MID/UPPER LEVELS, THE CONTINENTAL PATTERN WILL BE DOMINATED BY A VERY LARGE CYCLONE COVERING MUCH OF NORTHERN AND EASTERN CANADA, CENTERED NORTH OF HUDSON BAY. ASSOCIATED CYCLONIC FLOW WILL EXTEND ACROSS THE GREAT LAKES. THE LONG-LIVED RIDGE UPSTREAM -- INITIALLY POSITIONED OFF THE PACIFIC NORTHWEST TO THE MAIN BODY OF AK -- WILL DEAMPLIFY AND MOVE ASHORE FROM THE AK PANHANDLE TO INTERIOR WA/OR THROUGH THE PERIOD. MEANWHILE, TO ITS SOUTH, AN UNBROKEN SOUTHERN- STREAM FETCH WILL CONTINUE FROM OFF THE CA COASTLINE ACROSS THE SOUTHWEST AND SOUTHERN PLAINS, BLENDING INTO A BROAD AREA OF NEARLY ZONAL FLOW FROM THE MISSISSIPPI VALLEY EASTWARD. AN EMBEDDED TROUGH -- INITIALLY EVIDENT IN MOISTURE-CHANNEL IMAGERY FROM THE TX PANHANDLE TO SOUTHEASTERN NM AND FAR WEST TX -- WILL BE THE MAIN SHORTWAVE INFLUENCE FOR THIS FORECAST. AVAILABLE MORNING RAOBS AND RADAR-DERIVED WIND PROFILES ALREADY ARE STRENGTHENING AHEAD OF THIS FEATURE OVER CENTRAL AND NORTH TX. THIS PROCESS -- ALONG WITH INCREASING LARGE-SCALE LIFT -- WILL SPREAD EASTWARD ACROSS THE SOUTH IN STEP WITH THE TROUGH'S TRANSLATION EASTWARD TO PARTS OF AL/GA BY 12Z TOMORROW. AT THE SURFACE, 11Z ANALYSIS SHOWED A WAVY WARM FRONT FROM NEAR SSI ACROSS SOUTHERN GA, THE NORTHWESTERN FL PANHANDLE, TO NEAR MOB, HEZ, DRI, TO A WEAK LOW NEAR CLL. A DIFFUSE COLD TO QUASISTATIONARY FRONT EXTENDED FROM THERE SOUTHWESTWARD ACROSS THE LRD AREA. THE WARM FRONT IS EXPECTED TO SHIFT NORTHWARD THROUGH THE DAY, TO NORTHERN LA AND CENTRAL PORTIONS OF MS/AL/GA. FURTHER POLEWARD PROGRESS OF THE FRONT EFFECTIVELY SHOULD BE STALLED BY ONGOING AND INCREASING CONVECTION TO ITS NORTH, BEFORE MCS ACTIVITY OVERTAKES IT IN A WEST-EAST MANNER. ..EAST TX TO CAROLINAS MULTIPLE EPISODES OF SEVERE THUNDERSTORMS ARE EXPECTED TO CROSS THE OUTLINED SEVERE-RISK CORRIDOR THROUGH TOMORROW MORNING. IN AGGREGATE, THIS ACTIVITY SHOULD YIELD A SWATH OF DAMAGING WIND, TORNADOES AND LARGE HAIL. TORNADOES ARE POSSIBLE FROM SUPERCELLS NEAR THE WARM FRONT, IN THE WARM SECTOR, AND A COMBINATION OF LINE-EMBEDDED SUPERCELLS AND QLCS VORTICES WITH A DOMINANT MCS THAT IS FORECAST TO SWEEP ACROSS THE OUTLOOK AREA FROM WEST TO EAST. THE FORECAST ENVIRONMENTAL PARAMETER SPACE IN THE WARM SECTOR SUPPORTS THE POTENTIAL FOR SIGNIFICANT (EF2+ DAMAGE-PRODUCING) TORNADOES, ESPECIALLY WITH ANY RELATIVELY SUSTAINED SUPERCELLS AND DEEP/INTENSE LINE-EMBEDDED CIRCULATIONS. INITIAL SEVERE THREATS THIS MORNING SHOULD EVOLVE OUT OF ACTIVITY IN THE EASTERN AND WESTERN ENDS OF THE OUTLOOK SWATH. AN ONGOING AREA OF MOSTLY NON-SEVERE, ELEVATED THUNDERSTORMS OVER PARTS OF MS/AL MAY CONTINUE TO OFFER ISOLATED, SPORADIC LARGE-HAIL POTENTIAL, WHILE ITS SOUTHERN END ACCEPTS PROGRESSIVELY MORE-UNSTABLE INFLOW ROOTED NEARER TO THE SURFACE WITH TIME IN EASTERN AL AND GA. OTHER THUNDERSTORMS MAY DEVELOP OVER PARTS OF CENTRAL/SOUTHERN GA, MOVING INTO A DIURNALLY DESTABILIZING AIR MASS CLOSER TO THE GA COAST. MEANWHILE, AHEAD OF THE SHORTWAVE TROUGH, STRENGTHENING DEEP-LAYER LIFT WILL SUPPORT DEVELOPMENT AND UPSCALE GROWTH OF CONVECTION FROM CENTRAL/EAST TX EASTWARD THIS MORNING INTO AFTERNOON, AND PERHAPS FROM SOUTHEASTERN OK/NORTHEAST TX EASTWARD THIS AFTERNOON INTO OVERNIGHT. SIGNIFICANT-HAIL RISK SHOULD BE GREATEST RELATIVELY EARLY IN EITHER ASSOCIATED MCS-ORGANIZATION PROCESS, OR WHATEVER WARM-SECTOR SUPERCELLS FORM, IN A REGIME OF STEEP LOW/MIDDLE-LEVEL LAPSE RATES AND FAVORABLE DEEP SHEAR. AS THIS ACTIVITY SHIFTS QUICKLY EASTWARD, IT WILL ENCOUNTER RELATIVELY MAXIMIZED LOW-LEVEL SHEAR/LIFT ALONG THE WARM FRONT, AS WELL AS A WARM SECTOR CHARACTERIZED BY UPPER 60S TO LOW 70S F SURFACE DEW POINTS, GREATER DIURNAL HEATING, 2000-3000 J/KG MLCAPE, AND 40-55-KT EFFECTIVE-SHEAR MAGNITUDES. THOUGH WESTERLY SURFACE-WIND COMPONENTS WILL LIMIT HODOGRAPH SIZE SOMEWHAT, EFFECTIVE SRH OF 200-400 J/KG IS POSSIBLE IN THE WARM SECTOR, LARGER IN THE WARM-FRONTAL ZONE. STRONG-SEVERE THUNDERSTORMS SHOULD TRAIN ALONG AND NORTH OF THE FRONT AS FAR EAST AS COASTAL SC, UNTIL THE MCS ACTIVITY ARRIVES LATE TONIGHT INTO TOMORROW MORNING WITH A PREDOMINANT WIND/TORNADO THREAT. THE MAIN UNCERTAINTIES PRECLUDING GREATER PROBABILITIES AT THIS TIME ARE TWO-FOLD: 1. COVERAGE AND DURATION OF ANY SUPERCELLS IN THE FREE WARM SECTOR, ABOUT WHICH MOST SYNOPTIC AND CONVECTION-ALLOWING PROGS APPEAR SOMEWHAT RESERVED, IN THE ABSENCE OF STRONGER DEEP-LAYER/PRE-MCS FORCING, AND 2. MESSY NATURE OF THE DOMINANT STORM MODE: WHAT MAY BECOME ONE OR TWO LARGELY WIND-DOMINANT MCSS SWEEPING EASTWARD, WITH OCCASIONAL, EMBEDDED, SHORTER-LIVED (BUT STILL POTENTIALLY DESTRUCTIVE) TORNADIC MESOCIRCULATIONS.

ACUS11 KWNS 191222 SWOMCD SPC MCD 191222 LAZ000-TXZ000-191415- MESOSCALE DISCUSSION 0401 NWS STORM PREDICTION CENTER NORMAN OK 0722 AM CDT SUN APR 19 2020 AREAS AFFECTED...PORTIONS OF CENTRAL AND SOUTHEASTERN TX INTO FAR WESTERN LA CONCERNING...SEVERE POTENTIAL...TORNADO WATCH LIKELY VALID 191222Z - 191415Z PROBABILITY OF WATCH ISSUANCE...95 PERCENT SUMMARY...THUNDERSTORM ACTIVITY WILL INCREASE THROUGH THE MORNING FROM CENTRAL INTO SOUTHEASTERN TEXAS. VERY LARGE HAIL, A FEW TORNADOES AND DAMAGING WIND GUSTS ARE ALL POSSIBLE. A TORNADO WATCH WILL LIKELY BE NEEDED IN THE NEXT 1-2 HOURS. DISCUSSION...ELEVATED CONVECTION IS INCREASING THIS MORNING ACROSS PORTIONS OF CENTRAL TX WITH LARGE-SCALE ASCENT INCREASING AS A SHORTWAVE TROUGH BEGINS TO EJECT EASTWARD FROM NM INTO WESTERN TX. INITIAL CONVECTION WILL LIKELY REMAIN ELEVATED FOR A COUPLE OF HOURS UNTIL STRONGER HEATING AFTER SUNRISE ALLOWS SURFACE INHIBITION TO ERODE AND AS A WARM FRONT DRAPED ACROSS THE AREA CONTINUES TO LIFT NORTHWARD. NEVERTHELESS, VERY STEEP MIDLEVEL LAPSE RATES (7.5-8.5 C/KM) ARE CONTRIBUTING TO MUCAPE VALUES AROUND 2000 J/KG PER 12Z MESOANALYSIS AND THE 12Z FWD RAOB. EFFECTIVE SHEAR IS SUFFICIENT FOR STORM ORGANIZATION CURRENTLY, AND WILL CONTINUE TO IMPROVE OVER THE NEXT FEW HOURS. LARGE HAIL (SOME POTENTIALLY GREATER THAN 2 INCHES IN DIAMETER) WILL BE THE MAIN CONCERN IN THE IMMEDIATE NEAR-TERM, ESPECIALLY WITH ANY DISCRETE CELLS. WITH TIME, CONVECTION WILL BECOME SURFACE-BASED AS IT APPROACHES FAR EASTERN TX AND THE SABINE RIVER VALLEY LATE THIS MORNING. AS THIS OCCURS, AN INCREASING THREAT FOR TORNADOES AND DAMAGING WINDS WILL ACCOMPANY CONVECTION. WHILE LOW LEVEL HODOGRAPHS WILL BECOME ENLARGED BY LATE MORNING INTO THE AFTERNOON, DEEP-LAYER WINDS ARE RATHER UNIDIRECTIONAL ABOVE 3KM. THIS COULD RESULT IN STORM INTERACTIONS AND CLUSTERING TOWARD MIDDAY, WITH A MIX OF SEMI-DISCRETE CELLS AND CLUSTERS/BOWING SEGMENTS. AS SUCH, ALL SEVERE HAZARDS ARE ANTICIPATED AND SOME LOCATIONS COULD SEE MORE THAN ONE ROUND OF SEVERE STORMS.

Trend is slower.... 10Z HRRR has the Houston Metro and areas north starting the action about 15-16z