MESOSCALE PRECIPITATION DISCUSSION 0280
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
923 PM EDT TUE MAY 31 2016
 
AREAS AFFECTED...SOUTH TEXAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 010125Z - 010600Z
 
SUMMARY...EXTREMELY EFFICIENT RAINFALL PRODUCTION WITH RATES UP TO
4"/HR POSSIBLE AND HIGH TOTALS WITH FLASH FLOODING LIKELY. 

DISCUSSION...SOUTHWARD DEVELOPING COMPLEX CONTINUES TO ORGANIZE
WITH EMBEDDED STATIONARY SUPER CELLS THAT POSE A RISK FOR EXTREME
TOTALS AND LIFE-THREATENING LARGER SCALE FLASH FLOODING (MAINLY IN
KLABERG COUNTY...THOUGH SIMILARLY DEVELOPING IN BROOKS COUNTY). 
GIVEN SLOW MOVEMENT AND STRONG DEEPLY MOIST INFLOW (TPWS NEAR 2"
AND MLCAPES TO 2500 J/KG)...RAIN RATES UP TO 4"/HR...POTENTIALLY
SPIKED HIGHER WITH OCCASIONAL MERGERS FROM UPSTREAM DEVELOPMENT
NEAR THE RIO GRANDE MOVING EWARD.  

FLASH FLOODING THREAT WILL PERSIST THROUGH THE EARLY OVERNIGHT
HOURS...THOUGH EXACT EVOLUTION IS STILL QUESTIONABLE.  WV LOOP
INDICATES A BIT MORE INCREASED DIFFLUENCE AND DPVA ACROSS NORTH
CENTRAL MEXICO WITH CONTINUED HEIGHT FALLS UPSTREAM...THIS SHOULD
SUPPORT A DEVELOPING MCS ACROSS COAHUILA THAT WILL TRACK ACROSS
THE SIERRA MADRE.  CONCURRENTLY STRENGTHENING LOW LEVEL FLOW UP
THE RIO GRANDE WILL CONTINUE TO ADVECT HIGHER MST/INSTABILITY AS
FAR NORTH AS DEL RIO IN ADVANCE OF THE CONVECTIVE COMPLEX...WHICH
WILL SUPPORT IT TO DROP OFF THE TERRAIN AND DEVELOP SEWARD ALONG
THE RIVER TOWARD 06Z.  THE LARGE UNCERTAINTY IS IN RESPECT TO
ONGOING CONVECTION BUILDING BACK TOWARD THE ADVANCING COMPLEX AS
PRESENTED BY THE LAST FEW RUNS OF THE HRRR/HRRR VER.2 AND THE 12Z
NSSL-WRF...WHICH WOULD PRESENT THE POSSIBILITY OF CONTINUED
EXTREME TOTALS NEARING 5-8".   

GALLINA

ATTN...WFO...BRO...CRP...EWX...

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

LAT...LON   28759999 28479949 27969849 28369740 28149671 
            27509725 26809739 26279725 25939725 26259875 
            26529920 27009940 27569964 28070011 28730044