SPC MD 1395

MD 1395 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR CENTRAL/SE TX


MESOSCALE DISCUSSION 1395
NWS STORM PREDICTION CENTER NORMAN OK
1234 PM CDT SUN JUL 14 2013

AREAS AFFECTED...CENTRAL/SE TX

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 141734Z - 141900Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...THUNDERSTORM DEVELOPMENT IS EXPECTED IN THE NEXT COUPLE OF
HOURS /BY ABOUT 18-19Z/...AND THERE WILL BE A RISK FOR ISOLATED
DOWNBURSTS.  THE OVERALL SEVERE RISK APPEARS TO BE A LITTLE TOO
MARGINAL FOR A WATCH AT THIS TIME...BUT THIS AREA WILL CONTINUE TO
BE MONITORED THIS AFTERNOON.

DISCUSSION...VISIBLE SATELLITE IMAGERY AND SURFACE OBSERVATIONS SHOW
STRONG SURFACE HEATING ACROSS CENTRAL TX IN ADVANCE OF A SWWD-MOVING
COLD FRONT ASSOCIATED WITH A CLOSED MIDLEVEL LOW OVER NE OK/SE KS.
HIGH CLOUD DEBRIS FROM ONGOING CONVECTION OVER CENTRAL/N TX WILL
TEND TO INTERFERE WITH SURFACE HEATING ACROSS SE TX...WHILE
LOW-LEVEL MOISTURE DIMINISHES WITH NWWD EXTENT FROM THE HILL COUNTRY
TO THE EDWARDS PLATEAU.  IN BETWEEN ACROSS CENTRAL TX...THERE IS AN
AREA WITH SUFFICIENT BUOYANCY AND WEAKENING CONVECTIVE
INHIBITION...SUCH THAT THUNDERSTORM DEVELOPMENT IS BECOMING PROBABLE
IN THE ZONE OF LOW-LEVEL CONVERGENCE/ASCENT ALONG THE SURFACE COLD
FRONT.  DEEP-LAYER NLY FLOW WILL HELP STORMS MOVE SWD WITH THE
FRONT...INTO AN ENVIRONMENT WITH STEEP LOW-LEVEL LAPSE RATES/LARGE
DCAPE AND THE POTENTIAL FOR STRONG DOWNDRAFTS.  THERE WILL BE A
WINDOW OF OPPORTUNITY FOR ISOLATED DAMAGING OUTFLOW GUSTS THIS
AFTERNOON AS STORM MATURE...BUT THE OVERALL COVERAGE/INTENSITY OF
THE SEVERE STORM RISK IS SOMEWHAT IN QUESTION GIVEN RATHER MODEST
LAPSE RATES ALOFT AND THE OBSERVED TENDENCY FOR THE MIDLEVEL LOW TO
MOVE A LITTLE MORE WWD /VERSUS SWWD/ IN THE SHORT TERM.

..THOMPSON/CORFIDI.. 07/14/2013

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...HGX...EWX...SJT...

LAT...LON   30299674 30339655 30319641 30159622 29789633 29629658
            29489695 29479735 29499776 29679847 29899910 30339941
            30649942 30759924 30709896 30459858 30329815 30229756
            30259705 30299674

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