MESOSCALE PRECIPITATION DISCUSSION 0150
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
309 PM EDT FRI APR 29 2016
 
AREAS AFFECTED...CENTRAL TEXAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 291909Z - 292309Z
 
SUMMARY...MULTIPLE CONVECTIVE BANDS DEVELOPING IN DEEP MOISTURE
CHANNEL OUT OF THE WESTERN GULF.  FLASH FLOODING POSSIBLE GIVEN
RATES OVER 2" PARTICULARLY FURTHER EAST ALONG TPW AXIS. 

DISCUSSION...GOES-14 SRSO VIS/IR LOOP INDICATING CONVECTION
DEVELOPING ALONG EASTERN EDGE OF CHANNEL OF DEEPER MOISTURE
EXTENDING OUT OF THE FAR WESTERN GULF ACROSS CENTRAL TX. THIS
CONVECTION IS DEVELOPING ALONG THE RAP/BLENDED TPW MOISTURE AXIS
THAT CONTINUES TO INCREASE DUE TO STRONG LOW LEVEL MST TRANSPORT
ON 45-50KT LLJ PER VWP NETWORK...WITH VALUES OF 1.75" NEAR THE
GULF COAST AND UP TO 1.5" JUST EAST OF THE DFW METRO.  VIS LOOP
ALSO INDICATES A DRY SURGE INDICATED BY AN ARCHED ROLL CLOUD
MOVING THROUGH COASTAL TX/SW LA...THIS SURGE WILL CONTINUE
NORTHWARD AND ALLOW FOR CONTINUED LOW LEVEL STABILIZATION AND
SUPPORT A CONTINUED CORRIDOR OF DEEPER MOISTURE FLUX ON THE
INTERFACE.  DEEPER SOUTHERLY FLOW ALSO SUPPORTS CELL MOTIONS TO BE
ENE ALONG THIS INTERFACE LEADING TO POTENTIAL REPEAT/TRAINING
TRACKS.  THOUGH ORIENTATION TO THE LOW LEVEL FLOW WILL KEEP FLUX A
BIT LOWER THAN FURTHER NORTH NEAR THE E-W BOUNDARY ACROSS N TX/N
LA...THERE SHOULD BE SUFFICIENT FLUX TO KEEP CELL EFFICIENCIES
HIGH.  ADDITIONAL SUPPORT FOR WARM CLOUD/RAINFALL EFFICIENT IS
DRIVEN BY HIGH DENSITY OF SMOKE METEORS FROM YUCATAN/TABASCO
AGRICULTURAL FIRES AND WILL ACT AS CONDENSATION NUCLEI FOR MORE
NUMEROUS RAINDROP PRODUCTION... ALL CONSIDERED RATES OF 2-3"/HR
ARE PROBABLE.

FURTHER WEST...SURFACE CYCLOGENESIS SOUTH OF THE RED RIVER AND E
OF 100W IS PROVIDING INCREASED LOW LEVEL MOISTURE CONVERGENCE FROM
ISALLOBARIC FLOW TO INITIATE CONVECTION ALONG THE WESTERN EDGE OF
THE MOISTURE CHANNEL.  STEEPENED LAPSE RATES HELPS TO INCREASE
SBCAPES OVER 4000 J/KG. THESE FACTORS COMBINED WILL CONTINUE TO
DEVELOP/EXPAND CONVECTIVE COVERAGE...THAT WILL START TO PROGRESS
EASTWARD TOWARD THE DEEPER MOISTURE AND PRESENT A POSSIBILITY OF
CELL MERGERS AND EVENTUAL CONSOLIDATION INTO A LARGER CONVECTIVE
COMPLEX TOWARD MID-EVENING. 

CONFIDENCE IN EXACT MERGING/CONSOLIDATION SCENARIO IS A BIT LOWER
GIVEN MUCH OF THE HI-RES CAMS HAVE BEEN MUCH TOO SLOW IN
DEVELOPING THIS WESTERN CONVECTIVE LINE AND HAD FOCUSED ON THE
EASTERN MOISTURE AXIS DEVELOPMENT.  GREATER THREAT REMAINS FURTHER
EAST GIVEN SLOWER EASTWARD PROGRESSION OF THE LINE/MOISTURE
AVAILABILITY AND POTENTIAL FOR TRAINING.

GALLINA

ATTN...WFO...EWX...FWD...HGX...SHV...

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

LAT...LON   33189651 33059557 32629489 31809545 31289570 
            30559576 30169586 29949626 30479718 30609807 
            31009835 31789831 32709743