MESOSCALE PRECIPITATION DISCUSSION 0357
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
917 PM EDT WED JUN 21 2017

AREAS AFFECTED...EXT SOUTHEAST TX...SOUTHWEST LA

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 220115Z - 220600Z

SUMMARY...NORTH/SOUTH DEFORMATION ZONE NEAR SABINE RIVER CURRENTLY
FORMING AND LIKELY TO REMAIN A FAIRLY STATIONARY FORCING FOCUS
ALLOWING FOR COMPOUNDING HEAVY RAINFALL AND LIKELY FLASH FLOODING
CONDITIONS THROUGH EARLY OVERNIGHT HOURS. 

DISCUSSION...LAST GOES-16 VISIBLE IMAGERY AND EARLY OVERNIGHT SWIR
(3.9UM) CONTINUES TO SHOW PARTIALLY EXPOSED INNER CORE OF TS
CINDY. OVERALL THE INNER CORE HAS BEGUN TO CONSOLIDATE/TIGHTEN THE
INNER CORE.  WV AMVS SUGGEST 40KT 3H EVACUATION JET OVER CENTRAL
LA WITH THE MAIN INNER CORE OF THE 5H VORT CENTER ROTATING
NORTHWARD AS WELL PROVIDING DPVA ALLOWING FOR SURFACE PRESSURE
FALLS ELONGATING THE TROF TO THE NORTH ALONG THE SABINE RIVER. 
THIS PROVIDES A STRONG LOW LEVEL BOUNDARY FOR ISENTROPIC ASCENT ON
PERSISTENT 35-40KT 85H WINDS TO MAINTAIN DEEP CONVECTION WITH
LIMITED FORWARD MOTION (DEVELOPING DEFORMATION ZONE).  AS SUCH
MASS PILING AND MST CONVERGENCE WILL SUPPORT TPWS OVER 2.5" WITH
RATES UP TO 2.5"/HR.  GIVEN THE STRENGTHENING OF THE DEFORMATION
ZONE...THE FORCING/ASCENT IS EXPECTED TO REMAIN FAIRLY STATIONARY
LEADING TO THE POTENTIAL FOR 3-5" OF RAIN OVER THE NEXT 4-6 HRS
EXPECTED MOSTLY IN JEFFERSON COUNTY TX...ESPECIALLY IF DEVELOPING
NORTHWARD ROTATING BANDS BEGIN TO FILL IN AND CONVERGE. QUITE A
FEW HI-RES CAMS SUPPORT THIS EVOLUTION TO ALLOW FOR FAIRLY HIGH
TOTALS PARTICULARLY RECENT HRRR/HRRRX AND NSSL-WRF.  THOUGH FFG
VALUES ARE HIGHER...THESE TOTALS WILL LIKELY EXCEED THEM LEADING
TO FLASH FLOODING AFTER 03Z.

GALLINA

ATTN...WFO...HGX...LCH...SHV...

ATTN...RFC...LMRFC...WGRFC...

LAT...LON   31229371 30649307 30389270 30049233 29539251
            29619298 29689336 29589367 29489448 30189458
            31009422