DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 311632
SWODY1
SPC AC 311630

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT THU MAY 31 2012

VALID 311630Z - 011200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE OH...TN...AND LOWER MS
VALLEY SWWD ACROSS PARTS OF CENTRAL/SRN TX...

...OH VALLEY INTO LOWER MS VALLEY...
SHORT WAVE TROUGH OVER THE NRN PLAINS/MIDDLE MO VALLEY IS FORECAST
TO AMPLIFY AS A STRONG MID/UPPER LEVEL JET STREAK DIGS SEWD ACROSS
THE LOWER MO VALLEY. THIS WILL ALLOW A SURFACE LOW CURRENTLY OVER
SERN MO TO GRADUALLY DEEPEN AS IT MOVES INTO THE OH VALLEY TONIGHT.
A WARM FRONT EXTENDING ESEWD FROM THE LOW WILL LIFT SLOWLY
NWD...WHILE A COLD FRONT TRAILING SWWD FROM THE LOW ACROSS CENTRAL
AND SWRN TX WILL MOVE SEWD. LOW LEVEL MOISTURE WILL SPREAD NWD IN
ADVANCE OF THE SURFACE LOW AND CONTRIBUTE TO DESTABILIZATION THIS
AFTERNOON...WITH MUCAPE NEAR 1000 J/KG CLOSE TO THE WARM FRONT AND
SURFACE LOW. INSTABILITY INCREASES WITH SWD EXTENT INTO THE LOWER
MS VALLEY WHERE SURFACE DEW POINTS ARE IN THE LOW 70S IN LA
RESULTING IN MUCAPE TO 3000 J/KG.

STORMS HAVE INCREASED OVER SERN TX/SWRN LA AS THE SRN PART OF A
SHORT WAVE TROUGH MOVES EWD FROM ERN TX...AND ADDITIONAL STORMS ARE
DEVELOPING IN PARTS OF LA IN THE WEAKLY CAPPED AND QUITE UNSTABLE
ENVIRONMENT. SUFFICIENT SHEAR /25-30 KT IN THE LOWEST 6 KM/ IS
PRESENT TO SUPPORT ORGANIZED MULTICELL STORMS CAPABLE OF PRODUCING
LARGE HAIL AND DAMAGING WIND GUSTS.

FARTHER NORTH INTO THE OH AND TN VALLEYS...CONVECTION IS EXPECTED TO
INCREASE AHEAD OF TWO MCV/S...ONE LOCATED OVER SOUTH CENTRAL
AR...AND THE OTHER INDICATED OVER EAST CENTRAL MO. GENERALLY CLEAR
SKIES FROM SRN IND/FAR SRN IL INTO THE MID SOUTH WILL PROMOTE STRONG
DIABATIC HEATING AND CONTRIBUTE TO FURTHER AIR MASS DESTABILIZATION.
AS THE SWLY MID LEVEL FLOW INCREASES AHEAD OF THE STRENGTHENING
SHORT WAVE TROUGH...DEEP LAYER SHEAR WILL ALSO INCREASE AND SUPPORT
ORGANIZED STORM STRUCTURES. ACTIVITY IS EXPECTED TO SPREAD EWD WITH
ONE OR MORE CONVECTIVE LINES FORMING ALONG/AHEAD OF THE COLD
FRONT...WITH POTENTIAL TO PRODUCE DAMAGING WINDS ALONG WITH HAIL.
THERE MAY ALSO BE A LOCALLY ENHANCED THREAT FOR SEVERAL TORNADOES
/MAINLY NEAR THE SURFACE LOW AND WARM FRONT/ THIS AFTERNOON AND
EVENING.

...CENTRAL/SRN TX...
COMPLEX MESOSCALE PATTERN HAS EVOLVED WITH SEVERAL OUTFLOW
BOUNDARIES/GRAVITY WAVE-LIKE FEATURES PROPAGATING SWD IN ADVANCE OF
THE SYNOPTIC COLD FRONT. ELEVATED STORMS ARE SPREADING SWD INTO
PARTS OF CENTRAL TX AND MAY HAVE POTENTIAL TO PRODUCE MARGINALLY
SEVERE HAIL THE NEXT FEW HOURS. THERE IS CONSIDERABLE UNCERTAINTY
IN THE DEVELOPMENT/EVOLUTION OF SUBSEQUENT STORMS OVER CENTRAL/SOUTH
CENTRAL TX THIS AFTERNOON AND EVENING...BUT GIVEN STEEP MID LEVEL
LAPSE RATE ENVIRONMENT...ANY STORM CLUSTERS THAT DEVELOP WILL HAVE
POTENTIAL TO PRODUCE LARGE HAIL AND DAMAGING WINDS.

...SRN CO/NRN NM...

STEEP LAPSE RATES AND POST-FRONTAL DEWPOINTS IN THE 40S WILL YIELD A
MARGINALLY UNSTABLE ENVIRONMENT BY LATE AFTERNOON/EARLY EVENING
WITHIN THE LEE OF THE HIGHER TERRAIN. LOW-LEVEL UPSLOPE FLOW MAY BE
AUGMENTED BY THE SEWD PROGRESSION OF A WEAK MIDLEVEL
IMPULSE...GIVING RISE TO ISOLATED STORM DEVELOPMENT LATER TODAY.
GIVEN THE PRESENCE OF THE STEEP LAPSE RATES AND 30-35 KT OF DEEP
NWLY SHEAR...SETUP MAY SUPPORT A MARGINAL WIND/HAIL THREAT THROUGH
THIS EVENING.

..WEISS/HURLBUT.. 05/31/2012

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