MESOSCALE PRECIPITATION DISCUSSION 0113
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1130 PM EDT SUN JUN 08 2014
 
AREAS AFFECTED...OK/TX BORDER...AR/LA BORDER...WESTERN MS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 090329Z - 090929Z
 
SUMMARY...SCATTERED THUNDERSTORMS ARE BEGINNING TO FORM NEAR A
STATIONARY FRONT ACROSS NORTHEAST TX AS 850 HPA WINDS
INCREASE/CONVERGE INTO THE BOUNDARY.  THEY ARE EXPECTED TO
INCREASE IN COVERAGE AND ORGANIZATION WHICH COULD SPUR A FEW FLASH
FLOODS OVER THE NEXT SEVERAL HOURS.

DISCUSSION...A STATIONARY FRONT IS DRAPED ACROSS NORTHEAST TX AND
NORTHERN LA TOWARDS WEST-CENTRAL MS.  THE WIND FLOW AT 850 HPA IS
BEGINNING TO ACCELERATE AHEAD OF A PROGRESSIVE SQUALL LINE TOWARDS
THE BOUNDARY ACROSS NORTHEAST TX, SPURRING DEVELOPMENT OF
SCATTERED THUNDERSTORMS.  THE WIND SHEAR IN THE 0-6 KM LAYER IS
SUFFICIENT FOR ORGANIZED CONVECTIVE CLUSTERS.  CAPES ARE IN THE
NEIGHBORHOOD OF 1000-1500 J/KG AND PRECIPITABLE WATER VALUES ARE
1.75"-2".  THE STRENGTHENING LOW-LEVEL WINDS ARE BEGINNING TO
EXCEED THE MEAN LAYER FLOW BETWEEN 850-400 HPA, WHICH SHOULD
INCREASE PRECIPITATION EFFICIENCY.

THE ENVIRONMENT SHOULD BECOME MORE FAVORABLE FOR WET MULTI-CELL
CLUSTERS OVER THE NEXT SEVERAL HOURS AS 850 HPA WINDS INCREASE
TOWARDS 40 KTS.  HOURLY RAINFALL RATES OF 2" ARE ANTICIPATED.  AS
THE LOW-LEVEL FLOW INCREASES, BACKBUILDING STORMS ARE EXPECTED,
WHICH IS REFLECTED WITHIN THE 18Z GFS-BASED CORFIDI VECTORS.  CAPE
VALUES AND 0-3 KM SHEAR VALUES ALONG WITH WARM/ MOIST ATMOSPHERE
NEAR THE BOUNDARY SHOULD KEEP FORWARD PROPAGATION TO A MINIMUM. 
THERE IS A WEAK TO MODERATE SIGNAL IN THE CURRENT SUITE OF
MESOSCALE GUIDANCE OF A HEAVY RAIN EVENT.  RECENT RAINS SHOULD
HAVE BEGUN TO SATURATE SOILS NEAR THE OK/TX AND AR/LA BORDERS. 
OVERALL, BELIEVE A FEW SPOTS COULD RECEIVE FLASH FLOODING OVER THE
NEXT SEVERAL HOURS.

ROTH

ATTN...WFO...JAN...LZK...SHV...TSA...FWD...OUN...

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

LAT...LON   32059089 32329370 32749682 33449699 33879618 33919433
            33539078 32779007 32059089