Graphic for MPD #0232
 
MESOSCALE PRECIPITATION DISCUSSION 0232
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
833 AM EDT WED JUN 17 2015
 
AREAS AFFECTED...PORTIONS OF EASTERN TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 171232Z - 171832Z
 
SUMMARY...T.D. BILL IS EXPECTED TO CAUSE HEAVY RAINFALL WHICH
COULD CAUSE FLASH FLOODING.

DISCUSSION...TROPICAL DEPRESSION BILL IS LOCATED NORTHWEST OF WACO
TX AT THE PRESENT TIME.  PRECIPITABLE WATER VALUES (PER GPS
INFORMATION) ARE 2.5" NEAR ITS CORE AND MAIN INFLOW BAND.  INFLOW
AT 850 HPA IS 40-50 KTS PER VAD WIND PROFILES AND RECENT RAP
FORECASTS.  ITS CENTRAL PRESSURE HAS BEEN STEADY SINCE TUESDAY, SO
THIS DEGREE OF CLOUD BASE INFLOW IS UNLIKELY TO FADE MUCH TODAY. 
MUCAPES OF 1000-2000 J/KG ARE MAXIMIZED NEAR THE TX COAST, WHICH
HAS BEEN FUELING THUNDERSTORMS WITH 3"/HOUR RAIN RATES PER THE HGX
AND EWX RADARS OVER A SATURATED AREA.  STORM TOTALS ARE 6-9" PER
REGIONAL RADARS WITHIN JACKSON COUNTY, MAINLY SINCE 08Z.  SIMILAR
TOTALS WERE SEEN OVER AUSTIN COUNTY SINCE THIS TIME YESTERDAY PER
COCORAHS.

THE MESOSCALE QPF IS UNANIMOUS THAT LOCAL AMOUNTS OF 3-7" COULD
OCCUR JUST INLAND OF THE MIDDLE TX COAST.  THE 06Z SSEO
NEIGHBORHOOD PROBABILITIES SHOW A 50-100% CHANCE OF EXCEEDING THE
THREE HOUR FLASH FLOOD GUIDANCE IN AN AREA BOUNDED BY VICTORIA,
BURLESON, MONTGOMERY, AND BRAZORIA COUNTIES.  AS THE SYSTEM MOVES
NORTH, THE CONVECTION IN THE GULF SHOULD CONTINUE TO DECREASE IN
COVERAGE WHILE ACTIVITY NEAR THE MIDDLE TX COAST SHIFTS NORTH AT
10-15 KTS, PER FORWARD PROPAGATING CORFIDI VECTORS.  CONVERGENT
FLOW WITHIN THIS REGION SHOULD SLOWLY LESSEN AS INSTABILITY
INCREASES NEAR THE TAIL END OF THE INFLOW BAND PER RECENT RAP
FORECAST.  WITH THE CENTER MOVEMENT SLOWING TODAY, SOME OF THE
CORE RAINFALL COULD TRANSITION FROM A LONGER DURATION FLOOD EVENT
TOWARDS A FLASH FLOOD EVENT FOR THE DALLAS/FORT WORTH METRO AREA
OVER THE NEXT SEVERAL HOURS.  WITH HOURLY RAIN RATES NEAR THE CORE
OF 0.5-1" AN HOUR, AND WITHIN ITS FEEDER BAND OF 3" AN HOUR, FLASH
FLOODING REMAINS POSSIBLE.

ROTH

ATTN...WFO...CRP...EWX...FWD...HGX...LCH...OUN...SHV...

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

LAT...LON   34089728 34039622 33499518 32679436 31769410 
            31139403 29689411 29349467 28829535 27949705 
            28559804 29369857 29899723 30599630 31239627 
            31619725 31229802 32239883 33629833 


Last Updated: 833 AM EDT WED JUN 17 2015