MESOSCALE PRECIPITATION DISCUSSION 0210
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
554 PM EDT SAT MAY 14 2016
 
AREAS AFFECTED...SE TX...FAR SW LA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 142152Z - 150122Z
 
SUMMARY...NUMEROUS SLOW MOVING CELLS AND QUASI-ORGANIZED GROWTH
INTO AN MCS MAY PRODUCE FLASH FLOODING.

DISCUSSION...ALL THE FAMILIAR THERMODYNAMIC MARKERS WERE IN PLACE
TO SUPPORT VERY HEAVY RAIN RATES...WITH TYPICAL MAY MOISTURE AND
HEAT. HEAVY RAIN WAS ALREADY CONFIRMED WITH REPORTS OF 2.08 INCHES
IN ONE HOUR ON THE EAST SIDE OF HOUSTON FROM WFO HGX...AND A
REPORT OF 1.86 INCHES IN 45 MINUTES NEAR BURNET PER WFO EWX. EVEN
UNDER NORMAL CIRCUMSTANCES THIS EVENT WOULD REPRESENT AN ISOLATED
FLASH FLOOD THREAT...BUT THAT THREAT IS CERTAINLY ENHNACED BY
RECORD RAINFALL IN RECENT WEEKS/MONTHS...RESULTING IN WET SOILS
AND SWOLLEN CREEKS/STREAMS/BAYOUS.

SYNOPTIC FORCING WAS NOT STRONG...BUT A WEAKLY DEFINED SHORTWAVE
TROUGH WAS MORE THAN SUFFICIENT TO ALLOW STRONG CAPE AND
INITIATION ALONG CONVECTIVE OUTFLOWS TO DRIVE THIS EVENT. AT
2130Z...A LOOSELY ORGANIZED MCS WAS DRIFTING OUT OF THE HILL
COUNTRY TOWARD COASTAL SE TX...WHILE ISOLATED CELLS HAD ALSO
INITIATED THROUGHOUT THE HOUSTON METRO. A THIRD CLUSTER OF STORMS
WAS LOCATED JUST AHEAD OF A COLD FRONT SOUTH OF LUFKIN. THE
PRECIPITATION SIGNAL IN THE HRRR HAD INCREASED OVER THE MPD AREA.
GIVEN THE NUMBER OF ONGOING STORMS...IT IS LIKELY THE AVAILABLE
CAPE WILL BE CONSUMED. THERE IS A GRADIENT TOWARD DRIER AIR AND
GREATER DOWNDRAFT CAPE WITH EASTWARD EXTENT AWAY FROM HIGHWAY
287...SO STORMS MAY TEND TO BE MORE PROGRESSIVE AS THEY DEVELOP
TOWARD OR ENTER LOUISIANA. NEWLY DEVELOPING CELLS...HOWEVER...WILL
BE CAPABLE OF 2.5"/HOUR RATES...AND TOTALS APPROACHING 4 INCHES
ARE POSSIBLE WHERE MERGERS OCCUR...ESPECIALLY AHEAD OF THE MCS.

BURKE

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

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

LAT...LON   31709406 31129314 29929306 28859412 28819534 
            28399632 28279697 28799777 29509781 30019708 
            31389563