MESOSCALE PRECIPITATION DISCUSSION 0147
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1000 AM EDT FRI APR 29 2016
 
AREAS AFFECTED...AR...SOUTHEAST OK...FAR NORTHEAST TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 291400Z - 291900Z
 
SUMMARY...SIGNIFICANT FLASH FLOODING WILL BECOME MORE LIKELY
THROUGH EARLY AFTERNOON AS HEAVY SHOWERS AND THUNDERSTORMS EXPAND
IN COVERAGE AND REPEAT/TRAIN OVER THE SAME AREA.

DISCUSSION...A WELL-ORGANIZED MCS IMPACTING FAR SOUTHEAST OK AND
ACROSS SOUTHWEST TO CENTRAL AR IS PRODUCING VERY HEAVY RAINS WITH
AN EMBEDDED AXIS OF INTENSE TRAINING CELLS NOTED ALONG A LINE FROM
JUST NORTHEAST OF PARIS TX...TO DE QUEEN AND MOUNT IDA AR.

VERY COLD CONVECTIVE TOPS ALONG WITH EMBEDDED OVERSHOOTING TOPS
ALONG THE SOUTHWEST FLANK OF THE MCS AS SEEN IN THE GOES-OTD
ALGORITHM AND EARLY GOES-14 SRSO IMAGERY IS INDICATIVE OF
PERSISTING STRONG FORCING/UPDRAFTS...AND THIS IS BEING FACILITATED
BY LARGER SCALE ASCENT ASSOCIATED WITH A SPLIT-JET PATTERN ALOFT
OVER THE REGION AHEAD OF AN UPPER LOW EJECTING OUT INTO THE
SOUTHERN HIGH PLAINS. MEANWHILE...AREA VWPS ARE SHOWING A 50 KT
SOUTHERLY LOW LEVEL JET OVERRUNNING A WELL-DEFINED STATIONARY
FRONT JUST SOUTH OF THE RED RIVER VALLEY AND EXTENDING EAST ACROSS
SOUTHERN AR. THIS IS TRANSPORTING A HIGHLY FAVORABLE THERMODYNAMIC
ENVIRONMENT NORTH ACROSS EASTERN TX AND INTO THE BOUNDARY WHICH IS
FACILITATING THE SUSTAINABILITY OF THE MCS.

PWATS OF 1.5 TO 1.7 INCH PWATS AND MODERATE INSTABILITY WITH
MUCAPE VALUES OF 2000 TO 3000 J/KG IS POOLED ACROSS THE REGION AND
THIS WILL FOSTER HEAVY RAINFALL RATES THAT WILL REACH UP TO 2.5
INCHES/HR.

OVER THE NEXT FEW HOURS...EXPECT CONVECTION TO REMAIN WELL
ORGANIZED AND SUSTAINED AS STRONGER UPSTREAM FORCING ARRIVES FROM
THE WEST WITH IMPROVING JET DYNAMICS. THE MEAN LAYER FLOW SHOULD
CONTINUE IN A WSW/ENE FASHION WHICH WILL PROMOTE ADDITIONAL
TRAINING CELLS. THE LAST COUPLE OF RUNS OF THE HRRR STRONGLY
SUPPORT A SOUTHWESTWARD DEVELOPMENT OF CONVECTION BACK OVER MORE
AREAS OF SOUTHEAST OK AND INTO INTO NORTHEAST TX BY MIDDAY...WITH
EXCELLENT TRAINING POTENTIAL. WILL NEED TO MONITOR THIS VERY
CLOSELY.

EXPECT RAINFALL POTENTIAL OF 3 TO 5 INCHES THROUGH 19Z....HOWEVER
AREAS OF FAR SOUTHEAST OK AND INTO SOUTHWEST AR WHERE TRAINING HAS
ALREADY BEEN OCCURRING CAN EXPECT ADDITIONAL AMOUNTS IN EXCESS OF
6 INCHES LOCALLY...WITH SOME STORM TOTALS POSSIBLY APPROACHING 8
TO 10 INCHES BY MID-AFTERNOON. THIS WILL RESULT IN SIGNIFICANT AND
POSSIBLY LIFE-THREATENING FLASH FLOODING.

ORRISON

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

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

LAT...LON   35829217 35809094 35049038 34289076 33869162 
            33659235 33449365 33249471 32839594 32979668 
            33909671 34649608 35149532 35559411 35759300