MESOSCALE PRECIPITATION DISCUSSION 0207
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
151 PM EDT SAT MAY 14 2016
 
AREAS AFFECTED...CENTRAL/SOUTH TEXAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 141751Z - 142151Z
 
SUMMARY...ISOLATED FLASH FLOOD THREAT WITH STRONG STATIONARY CELLS
WITH RATES.  

DISCUSSION...A WEAK COLD FRONT MOVING SOUTH BISECTS CENTRAL TX
FROM S OF JSO TO HLR OUT TO NEAR FST.  AN EARLY MORNING CONVECTIVE
COMPLEX ORIGINATING OUT OF REAL/EDWARDS COUNTY PROVIDES ADDITIONAL
BOUNDARIES TO FOCUS LOCALIZED MST CONVERGENCE.  GOES-14 SRSO AND
RADAR MOSAIC INDICATE THE ACTIVATION OF THE CONVECTION
ALONG/BETWEEN THE BOUNDARIES ALONG THE THETA-E AXIS WHICH IS
GENERALLY COINCIDENT WITH A ZONE OF TPW THAT IS AT 1.5" OR GREATER
(POOLED BEST ALONG THE RIO GRANDE WITH VALUES UP TO 2.0"). 
MLCAPES OF 1500-2000 J/KG IS AVAILABLE FOR ENERGETIC UPDRAFTS.   A
POTENTIAL LIMITING FACTOR IS FLOW IS GENERALLY WEAK IN THE LOW
LEVELS BUT THIS ALSO SUPPORTS STATIONARY CELL MOTION TO ALLOW FOR
CELLS TO RAPIDLY PRODUCE RATES UP TO 2.0"/HR.  ABOVE THE STEERING
LAYER...UPPER LEVEL FLOW IS FAIRLY GOOD WITH 40-50 KTS OBSERVED TO
PROVIDE GOOD EVACUATION FOR THE UPDRAFTS.  THIS SETUP HAS THE
POTENTIAL TO SETUP ENOUGH INFLOW FROM THE UPDRAFTS TO KEEP
UPDRAFT/DOWNDRAFTS SEPARATED ENOUGH FOR SOME ISOLATED AREAS TO
LEAD TO TOTALS IN EXCESS OF 3"...NEARING FF VALUES...AS WAS THE
CASE THIS MORNING IN REAL/EDWARDS COUNTY.  MORE LIKELY CELLS WILL
PROPAGATE SLOWLY SOUTH PARTICULARLY FURTHER EAST ALONG THE COLD
FRONT WHERE COLD POOLS REINFORCED BY THE FRONT WILL BE SUFFICE TO
ACTIVATE NEW CELLS.  

FURTHER SOUTHWEST...MATURE MCS/COLLIDING OUTFLOW BOUNDARIES WILL
PROVIDE SIMILAR SHORT-TERM HIGH RATE THREAT PARTICULARLY IN CELL
MERGERS...WITH RATES UP TO 3"/HR GIVEN THE HIGHER MOISTURE
AVAILABILITY.  

GALLINA

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

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

LAT...LON   31329490 30679484 30249504 29609715 27589846 
            28069950 28260040 28809950 30009913 30279934 
            30390009 29580095 29860169 29930151 30680150 
            30870145 31070083 30859929 31169718 31179635 
            31319527