The Storm Prediction Center issued the first Day 1 severe weather outlook about an hour ago. These outlooks are updated every five to six hours throughout the day. They contain more detail about specific severe weather hazards along with a synopsis of the setup. We continue to expect the severe weather threat to increase around sunset across the eastern Texas Panhandle and Northwest Texas. These initial storms have the potential to be supercellular with tornado and large hail potential. By mid-evening we should have a line of strong to severe storms extending from Kansas south through Oklahoma and Texas. That line will move east around 40 MPH tonight into Tuesday morning with a continued threat of damaging wind gusts and embedded brief tornadoes. Timing aspects have not changed from our evening blog update. Any thunderstorms that develop ahead of the line tonight or have the opportunity to become discrete could become tornadic. We’ll watch for those storms closely. We’ll have a complete forecast update with our usual Texas Weather Roundup around 6:30 AM.
SEVERE STORMS ARE EXPECTED TO DEVELOP INITIALLY OVER THE CENTRAL AND
SOUTHERN HIGH PLAINS DURING THE LATE AFTERNOON AND EVENING. AN
EXTENSIVE SQUALL LINE SHOULD FORM TONIGHT AND PUSH EASTWARD ACROSS
PARTS OF OKLAHOMA AND TEXAS. TORNADOES…DAMAGING WINDS…AND LARGE
HAIL ARE ANTICIPATED.
A POWERFUL 150 KT JET STREAK WILL MOVE EWD ACROSS NRN MEXICO INTO
SWRN TX DURING THE DAY 1 PERIOD CONCURRENT WITH AN INTENSE MID-LEVEL
TROUGH/LOW PROGRESSING EWD FROM THE 4 CORNERS INTO THE SRN-CNTRL
HIGH PLAINS. A SURFACE LOW IS FORECAST TO DEVELOP OVER THE CNTRL
HIGH PLAINS AND SLOWLY MIGRATE EWD WHILE A DRYLINE WILL EXTEND SWD
THROUGH THE SRN HIGH PLAINS DURING THE AFTERNOON. A PACIFIC COLD
FRONT IS FORECAST TO OVERTAKE THE DRYLINE DURING THE EVENING AND
SURGE EWD ACROSS W TX AND THRU THE OK I-35 CORRIDOR OVERNIGHT.
FARTHER S…SURFACE-BASED INITIATION WILL PROBABLY BE DELAYED UNTIL
THE LATE AFTERNOON. SCTD STORM DEVELOPMENT IS EXPECTED DURING THE
21-00Z PERIOD ALONG THE DRYLINE. AN AXIS OF MODERATE BUOYANCY IS
PROGGED BY MODEL GUIDANCE /1000-1500 J PER KG SBCAPE/ AND STRONG
DEEP-LAYER SHEAR. THE STRONGER UPDRAFTS WILL DEVELOP INTO
SUPERCELLS AND THE INITIAL SEVERE RISK WILL INCLUDE LARGE TO VERY
LARGE HAIL…SEVERE GUSTS…AND ISOLD TORNADOES. DURING THE
EVENING…HODOGRAPHS ARE FORECAST TO ENLARGE /300-500 M2 PER S2
EFFECTIVE SRH/ ALONG WITH A GRADUAL MOISTENING IN THE PBL ACTING TO
TEMPER NOCTURNAL COOLING AND MAINTAIN SURFACE-BASED OR NEAR
SURFACE-BASED BUOYANCY PROFILES ACROSS SRN OK AND WRN N-CNTRL TX.
AT THE SAME TIME…A RAPID PROGRESSION IN UPSCALE GROWTH IS EXPECTED
TO OCCUR AS THE PACIFIC FRONT SURGES E AND STORM MERGERS OCCUR. IT
IS PLAUSIBLE A SEVERE-WIND PRODUCING SQUALL LINE WITH EMBEDDED
BOWS/LEWPS AND MESOVORTICES YIELDS SWATHS OF WIND DAMAGE AS THE WIND
FIELDS INTENSIFY BY MID-LATE EVENING. LESS CERTAIN/LOWER
PROBABILITY IS MAINTAINING CELLULAR MODES FARTHER E THAN ANTICIPATED
AND/OR ADDITIONAL STORMS DEVELOPING AHEAD OF THE LINE WHICH WOULD
PERHAPS FAVOR A GREATER TORNADO RISK. NONETHELESS…A GRADUAL
DECREASE IN BUOYANCY FARTHER E TOWARDS THE ARKLATEX WILL TEMPER THE
THREAT FOR WIND DAMAGE COMPARED TO AREAS FARTHER W.