MESOSCALE PRECIPITATION DISCUSSION 0066
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
951 AM EDT SAT MAY 09 2015
 
AREAS AFFECTED...PORTIONS OF THE TX PANHANDLE & OK 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 091350Z - 091950Z
 
SUMMARY...THUNDERSTORMS WITH HEAVY RAINFALL WITH SPREAD FROM THE
TX PANHANDLE THROUGH WESTERN AND CENTRAL OK OVER THE NEXT SEVERAL
HOURS.  HOURLY RAIN RATES UP TO 1.75" COULD CAUSE FLASH FLOODING.

DISCUSSION...LIKE THE LAST TWO MORNINGS, A SHORTWAVE ALOFT NEAR
THE SOUTHEAST NM/ WEST- CENTRAL TX HAS SPURRED MORNING CONVECTION
ACROSS THE TX PANHANDLE.  PRECIPITABLE WATER VALUES ARE NEAR
1.25".  CAPES UPSTREAM ARE 2000-4000 J/KG DUE TO A CAPPING
INVERSION ALOFT, REFLECTED REASONABLY WELL IN THE 9C 700 HPA
ISOTHERM, AND 850 HPA INFLOW INTO THE REGION IS 40 KTS (NEAR THE
MAGNITUDE OF THE 850-400 HPA MEAN WIND) -- THIS HAS LED TO GREATER
ORGANIZATION TO THE CONVECTION THAN SEEN THIS TIME THURSDAY OR
FRIDAY.  WHEN SUBTRACTING THE SURFACE WINDS, THERE IS 30 KTS OF
AVAILABLE CLOUD BASE INFLOW.  SOUNDINGS SHOW GOOD TURNING OF WINDS
WITH HEIGHT -- BOTH THE WIND VEERING AND CAPE VALUES FAVOR FORWARD
PROPAGATION.  

THERE SHOULD BE SOME NORTHWARD MOVEMENT TO THE OUTFLOW BOUNDARY IN
NORTHERN TX DURING THIS PERIOD, SIMILAR TO YESTERDAY.  A BLEND OF
THE FORWARD PROPAGATION/CORFIDI VECTORS SUGGESTS EAST-NORTHEAST
MOTION TO ONGOING THUNDERSTORM ACTIVITY, WHICH SHOULD BECOME MORE
SURFACE-BASED CLOSER TO THE TX/OK BORDER BY 17Z PER CONCEPTUAL
MODELS AND RECENT RAP FORECASTS.  CELL TRAINING IS THE MAIN FLASH
FLOOD THREAT WHERE THUNDERSTORMS CAN ALIGN DUE TO EXPECTED
EMBEDDED MESOCYCLONES WITHIN CONVECTIVE BANDS.  THE 06Z CANADIAN
REGIONAL MODEL ALONG WITH RECENT RAP AND HRRR RUNS ARE HANDING
THIS CONVECTION REASONABLY WELL -- NO OTHER AVAILABLE MESOSCALE
GUIDANCE HAS RAIN NEAR THIS REGION.  RAIN RATES THIS MORNING PER
RADAR ESTIMATES ARE NEAR 1.75" AN HOUR, WHICH SHOULD PERSIST FOR
THE TIME BEING -- RAIN RATES COULD INCREASE WITH TIME AS THE
CONVECTION MOVES INTO A MORE MOIST ENVIRONMENT LATER TODAY.  FLASH
FLOODING IS CONSIDERED POSSIBLE.

ROTH

ATTN...WFO...AMA...FWD...ICT...LUB...OUN...SGF...SHV...TSA...

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

LAT...LON   37159476 36689460 35799457 33789453 33359544 
            33719753 33749866 33689948 33630027 33800135 
            35070135 35550074 36090046 36559914 36779731 
            36849671 36879587