MESOSCALE PRECIPITATION DISCUSSION 0226
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
738 PM EDT SUN MAY 22 2016
 
AREAS AFFECTED...EAST TX PANHANDLE TO WEST TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 222337Z - 230330Z
 
SUMMARY...CELLS WHICH WERE PRODUCING VERY HEAVY RAINFALL WERE
BECOMING MORE NUMEROUS.  GIVEN THE CELL MOTION...THERE IS THE
POTENTIAL FOR FLASH FLOODING FROM THE EASTERN TX PANHANDLE
WESTWARD TO THE DRY LINE OVER WEST TX. 

DISCUSSION...HEAVY RAINFALL PRODUCING CELLS WERE BECOMING MORE
NUMEROUS AROUND 23Z ALONG A NORTH TO SOUTH ORIENTED INSTABILITY
AXIS WHERE ML CAPES WERE ON THE ORDER 2500 TO 3500 J PER KG AND
ALONG A PLUME OF HIGHER PRECIIPTABLE WATER VALUES RUNNING 1.5 TO
1.75 INCHES.  THE WESTERN BOUNDARY OF THE CONVECTION SHOULD BE
ALONG AND EAST OF A WELL DEFINED DRY LINE WHICH SEPARATES
DEWPOINTS IN THE UPPER 60S FROM DEWPOINTS IN THE TEENS AND 20S.

THE MESOSCALE CONVECTIVE ALLOWING MODELS HAVE BEEN STRUGGLING A
BIT WITH RESPECT TO WHERE AND WHEN CONVECTION WOULD FORM.  EARLIER
RUNS OF THE HRRR WERE VERY AGGRESSIVE IN TERMS OF HEAVY RAINFALL
OVER THE EASTERN TX PANHANDLE.  WHILE IT HAS BACKED OFF SOME ON
THE RAINFALL AMOUNTS...CELLS WHICH HAVE DEVELOPED HAVE SHOWN SOME
TENDANCY TO TRAIN OVER THE SAME SPOTS AS THEY MOVE NORTHWARD IN
ROUGHLY THE AREA SHOWN BY THE HRRR.  THE HRRR TIME LAGED ENSEMBLE
SHOWED HIGHEST PROBABILITIES FOR 2 INCH PER 3 HOURS...AND SOME
CASES OF 2 INCHES PER HOUR...PERSISTING INTO MID EVENING IN THIS
AREA.  THE WRF NMM APPEARED TO BE TOO HEAVY WITH ITS RAINFALL
AMOUNTS BUT HAD THE SUPPORT OF THE WRF ARW IN TERMS OF PLACEMENT. 
THIS WOULD RESULT IN RAINFALL AMOUNTS APPROACHING THE FLASH FLOOD
GUIDANCE VALUES OF 2.5 TO 3 INCHES PER 3 HOURS IN THIS AREA.

WHILE THE THREAT MAY END SOMEWHAT EARLIER OVER THE WESTERN PART OF
THE MPD AREA...THERE ARE AT LEAST SOME SIGNALS THAT THE HEAVY
RAINFALL AND THE POSSIBILITY OF FLASH FLOODING...MAY PERSIST AS
FAR EAST AS SWW / SWEETWATER TX/ BY 03Z.  


BANN

ATTN...WFO...AMA...LUB...MAF...OUN...SJT...

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

LAT...LON   36180089 36009997 34169891 32519934 31380054 
            31910172 33290145 34920115