MESOSCALE PRECIPITATION DISCUSSION 0098
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
131 PM EDT WED MAR 30 2016
 
AREAS AFFECTED...NE TEXAS...SE OKLAHOMA...W CENTRAL ARKANSAS...NW
LOUISIANA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 301730Z - 302230Z
 
SUMMARY...NUMEROUS SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN ARE
DEVELOPING ACROSS THE ARKLATEX REGION AND ARE EXPECTED TO CONTINUE
INTO THE AFTERNOON HOURS.  TRAINING OF THUNDERSTORM CELLS MAY LEAD
TO LOCALIZED FLOODING ISSUES THROUGH 21Z WITH RAINFALL RATES ON
THE ORDER OF 2 INCHES PER HOUR.

DISCUSSION...IN ADVANCE OF A SLOW-MOVING STRONG COLD FRONT OVER
WESTERN TEXAS, A BROAD WARM SECTOR HAS BECOME ESTABLISHED OVER
MUCH OF EASTERN TEXAS AND EXTENDING INTO ARKANSAS AND LOUISIANA. 
THIS WARM/MOIST SECTOR HAS BEEN CHARACTERIZED BY DEW POINTS IN THE
MID 60S TO NEAR 70 DEGREES AND MUCAPES OF 1000 TO 2000 J/KG. 
MOISTURE ADVECTION HAS BEEN ON THE INCREASE AS A RESULT OF THE
40-50 KNOT LOW LEVEL JET.  AMPLE MOISTURE COUPLED WITH STRONG LEFT
EXIT REGION JET DYNAMICS AND DIVERGENT 500MB FLOW SHOULD LEAD TO A
LENGTHY PERIOD OF SUSTAINABLE CONVECTION.

RECENT HI RES MODEL GUIDANCE SUPPORTS MULTIPLE SMALL SCALE AXES OF
SW TO NE ORIENTED HEAVY RAINFALL INTO THE MID TO LATE AFTERNOON
HOURS FROM NORTHEAST TEXAS TO NORTHWEST ARKANSAS.  THE
EXPERIMENTAL HRRR FROM ESRL SEEMED TO HANDLE THE MESOSCALE SET-UP
BEST THROUGH THIS AFTERNOON, WITH CELL MERGERS LEADING TO GREATER
ORGANIZATION OVER WESTERN ARKANSAS, WITH EVENTUAL EXTENSION DOWN
INTO NORTHEAST TEXAS, AND APPROACHING NORTHWEST LOUISIANA. THE
LARGEST INHIBITING FACTOR FOR A BROADER SCALE THREAT FOR THE TIME
BEING IS THE SCATTERED NATURE OF THE INITIAL DEVELOPMENT.  BY
EVENING, CONSOLIDATED OUTFLOW MAY LAY DOWN FROM WEST TO EAST
ACROSS SOUTHERN ARKANSAS AND ADJACENT PARTS OF TX/LA/MS, AS
SUGGESTED BY CONSECUTIVE WRF-ARW RUNS, WITH STRONG SOUTHERLY
INFLOW THEN RESULTING IN TRAINING AND A MORE FOCUSED FLASH FLOOD
THREAT.

HAMRICK

ATTN...WFO...FWD...LZK...MEG...PAH...SGF...SHV...TSA...

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

LAT...LON   36719207 36479074 34909159 33819207 32949251 
            32509315 32409427 32439532 32839580 33659572 
            34499546 35349498 36029452 36579371