MESOSCALE PRECIPITATION DISCUSSION 0147
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
426 PM EDT SUN JUN 22 2014
 
AREAS AFFECTED...PORTIONS OF N-CNTRL TEXAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 222025Z - 230025Z
 
SUMMARY...A SMALL BUT PERSISTENT AREA OF HEAVY RAIN SOUTH AND WEST
OF THE DALLAS-FORT WORTH METRO REGION IS EXPECTED TO PERSIST OVER
THE NEXT FEW HOURS WITH A GRADUAL SHIFT SWD...FOLLOWED BY GRADUAL
WEAKENING TOWARD 00Z. 

DISCUSSION...LOCALIZED RAINFALL RATES OF 1 TO 2 IN/HR HAVE BEEN
OBSERVED OVER SEVERAL COUNTIES JUST SOUTH AND WEST OF THE
DALLAS-FORT WORTH METRO WITH TOTALS OF 4 TO 6 INCHES SINCE EARLY
THIS MORNING PER COOP REPORTS. MEAN LAYER FLOW REMAINS RELATIVELY
WEAK TOWARD THE EAST AT 10 TO 15 KTS WITH MOIST 925-850 MB INFLOW
ATOP A WELL DEFINED OUTFLOW BOUNDARY NEAR 25 TO 30 KTS ALLOWING
REGENERATION OF CONVECTION OVER THE SAME AREAS. THERE HAS BEEN
SOME GRADUAL WEAKENING OF THE INFLOW BY 5 TO 10 KTS PER KGRK VAD
WIND PROFILE OBSERVED OVER THE PAST COUPLE OF HOURS...AS WELL AS A
SLIGHT VEERING TOWARD THE SSW. 

THE AREA REMAINS CONNECTED TO LOW LEVEL MOIST INFLOW FROM THE GULF
AS WELL AS MOISTURE ALOFT WITH A SUBTROPICAL CONNECTION TIED TO A
DISTURBANCE IN THE EASTERN PACIFIC...JUST SOUTHWEST OF THE BAJA
PENINSULA. A SLOW EASTWARD PROGRESSION TO THE MESOSCALE UPPER WAVE
OVER DALLAS-FORT WORTH IS EXPECTED WHICH SHOULD CAUSE CONTINUED
VEERING OF THE LOW LEVEL INFLOW...HELPING TO OFFSET THE CURRENT
BALANCE IN PLACE. A GRADUAL SWD OR SWWD SHIFT IN THE HEAVIEST
RAINS IS EXPECTED THROUGH THE REMAINDER OF THE EVENING FOLLOWED BY
GRADUAL DISSIPATION. 

THIS IDEA IS SUPPORTED BY RECENT RUNS OF THE HRRR AND 12Z NSSL WRF
WHICH HAVE BEEN HANDLING THE ONGOING RAINFALL REASONABLY WELL.

OTTO

ATTN...WFO...FWD...SJT...

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

LAT...LON   31099781 31549891 32779924 33329813 33349711 32959600
            31939584 31209660 31099781