733
ACUS01 KWNS 230558
SWODY1
SPC AC 230557
DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1257 AM CDT SAT MAR 23 2019
VALID 231200Z - 241200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL
OK INTO NORTH-CENTRAL TX...
..SUMMARY
ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS PORTIONS OF
CENTRAL OKLAHOMA INTO NORTH-CENTRAL TEXAS LATE THIS AFTERNOON INTO
EARLY EVENING. LARGE HAIL AND DAMAGING WIND WOULD BE THE PRIMARY
THREAT WITH ANY SEVERE STORM THAT DEVELOPS.
..SYNOPSIS
A MID/UPPER-LEVEL TROUGH WILL MOVE NORTHEASTWARD FROM THE
CENTRAL/SOUTHERN PLAINS INTO THE UPPER MIDWEST TODAY INTO TONIGHT,
AS AN UPSTREAM UPPER TROUGH MOVES INTO THE GREAT BASIN AND INTERIOR
NORTHWEST. AT THE SURFACE, A WEAK CYCLONE WILL MOVE FROM THE CENTRAL
HIGH PLAINS INTO THE UPPER MIDWEST BY SUNDAY MORNING, WHILE A LEE
TROUGH/WEAK CYCLONE WILL PERSIST OVER THE SOUTHERN HIGH PLAINS AS
MODERATE MIDLEVEL WESTERLY FLOW IS MAINTAINED OVER THE SOUTHERN
ROCKIES.
..CENTRAL/EASTERN OK...NORTH-CENTRAL/NORTHEAST TX
WEAK ELEVATED CONVECTION IS LIKELY TO BE ONGOING ACROSS OK AND NORTH
TX THIS MORNING. THIS ACTIVITY MAY PERSIST ACROSS EASTERN
OK/NORTHEAST TX INTO THE AFTERNOON, BUT THE I-35 CORRIDOR ACROSS
OK/TX WILL LIKELY BEGIN TO CLEAR OUT BY MIDDAY DUE TO SUBSIDENCE IN
THE WAKE OF THE MIDLEVEL TROUGH MOVING ACROSS KS. MODEST LOW-LEVEL
MOISTURE RETURN TO THE EAST OF A WEAK PACIFIC COLD FRONT/EFFECTIVE
DRYLINE WILL ALLOW FOR DEWPOINTS TO RISE INTO THE MID 50S ACROSS
CENTRAL OK TO AROUND 60 INTO NORTH TX. IN CONJUNCTION WITH DIURNAL
HEATING, THESE DEWPOINTS WILL BE SUFFICIENT TO SUPPORT MLCAPE OF
500-1500 J/KG, GIVEN RELATIVELY COLD TEMPERATURES ALOFT (-15C TO
-18C AT 500 MB). MODEST LOW-LEVEL SOUTH-SOUTHEASTERLY FLOW VEERING
TO MODERATE WESTERLY FLOW ALOFT WILL SUPPORT EFFECTIVE SHEAR OF
40-50 KT, SUFFICIENT TO SUPPORT A CONDITIONAL RISK OF ORGANIZED
CONVECTION.
A CONSIDERABLE AMOUNT OF UNCERTAINTY REMAINS REGARDING THE COVERAGE
OF SURFACE-BASED CONVECTION ALONG/AHEAD OF THE DRYLINE LATE THIS
AFTERNOON INTO THIS EVENING. LARGE-SCALE SUPPORT APPEARS NEUTRAL AT
BEST, WITH LOW-LEVEL CONVERGENCE LIKELY TO BE MODEST ALONG THE
DRYLINE. MOST HREF MEMBERS FAIL TO SUSTAIN SURFACE-BASED CONVECTION
ALONG/AHEAD OF THE DRYLINE, BUT THE LATEST NAM/GFS/ECMWF CONTINUE TO
GENERATE CONVECTIVE PRECIPITATION NEAR AND AFTER 00Z. GIVEN THE
POTENTIAL FOR ISOLATED SUPERCELL DEVELOPMENT LATE THIS AFTERNOON OR
EARLY EVENING ALONG OR JUST WEST OF THE I-35 CORRIDOR, A HIGHLY
CONDITIONAL MARGINAL RISK FOR HAIL/WIND HAS BEEN INTRODUCED WITH
THIS OUTLOOK.
REGARDLESS OF DEVELOPMENT ALONG THE DRYLINE, THERE IS SOMEWHAT
GREATER CONFIDENCE IN THE DEVELOPMENT OF ELEVATED CONVECTION TONIGHT
ACROSS EASTERN OK INTO NORTHEAST TX, AS ISENTROPIC LIFT INCREASES IN
RESPONSE TO A MODEST INTENSIFICATION OF THE LOW-LEVEL JET. ELEVATED
BUOYANCY MAY BE SUFFICIENT TO SUPPORT SOME HAIL WITH THIS ACTIVITY,
THOUGH STORMS LATE TONIGHT ACROSS THIS AREA ARE EXPECTED TO LARGELY
REMAIN SUBSEVERE.
..KS
A CONDITIONALLY FAVORABLE ENVIRONMENT FOR ORGANIZED CONVECTION WILL
ALSO LIKELY DEVELOP INTO PORTIONS OF SOUTH-CENTRAL/SOUTHEAST KS,
THOUGH WITH SIMILAR UNCERTAINTY REGARDING INITIATION AND LESS
BUOYANCY COMPARED TO AREAS FURTHER SOUTH, THE MARGINAL HAS NOT BEEN
EXTENDED INTO KS AT THIS TIME. FURTHER NORTH INTO NORTH-CENTRAL KS,
STORM COVERAGE IS LIKELY TO BE GREATER IN CLOSER PROXIMITY TO THE
MIDLEVEL LOW. WHILE BUOYANCY WILL WEAKER IN THIS AREA, COLD MIDLEVEL
TEMPS MAY SUPPORT SOME HAIL RISK, AND A MARGINAL RISK MAY BE
REQUIRED IF A MODEST AMOUNT OF DIURNAL HEATING APPEARS LIKELY THIS
AFTERNOON.
..DEAN/NAUSLAR.. 03/23/2019
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