MESOSCALE PRECIPITATION DISCUSSION 0606
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1201 AM EDT SAT OCT 24 2015
 
AREAS AFFECTED...TEXAS...EXT SW ARKANSAS...EXT NW LOUISIANA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 240401Z - 241001Z
 
SUMMARY...LITTLE CHANGE IN SETUP OVER THE NEXT FEW HOURS WITH
BACKBUILDING AND TRAINING FOR CONTINUED SIGNIFICANT FLASH FLOODING
EVENT. 

DISCUSSION...WV LOOP CONTINUES TO SHOW AN IDEAL UPPER LEVEL
DIVERGENCE PATTERN WITH INCREASING UPSTREAM ENERGY TO SUPPORT A
LONG ZONE COINCIDENT WITH SURFACE FRONTAL ZONE OF BACKBUILDING
CONVECTION WITHIN A TRAINING PROFILE.  ADDITIONALLY DUAL JET
STRUCTURE WITH ENTRANCE TO POLAR JET AND EXIT TO SUBTROPICAL JET
-- OUTFLOW CHANNEL OF TC PATRICIA...ALSO CURVES ANTICYCLONICALLY
OVER SOUTH TEXAS FOR ADDITIONAL DIFFLENCE TO SUPPORT THIS LARGE
ZONE OF FOCUSED UVVS.  AT THE SURFACE THE STATIONARY FRONT
CONTINUES TO ACT AS THE FOCUS OF STRONG MOISTURE CONVERGENCE/FLUX
FROM A BROAD 20-25 KT LLJ. WITH A WEAK UPPER LEVEL WAVE LIFTING
INTO SOUTH CENTRAL OK AS SEEN BY THE S/W RIDGING IN THE WV
LOOP...LLJ IS A BIT MORE FOCUSED WITH HIGH WINDS AS WELL AS VEERED
LOW LEVEL FLOW TO FOCUS MAXIMIZED CONVERGENCE NEAR SAN
SABA/MASON/LLANO VICINITY COUNTIES.  THIS IS THE NOSE OF THE WEDGE
OF NEARLY STATIONARY COLDER TOPS SEEN IN IR.   A SECOND WEDGE NEAR
SUTTON COUNTY IS ALSO A MAXIMIZED AREA OF INCREASED MOISTURE
CONVERGENCE WHERE LOW LEVEL FLOW IS CHANNELED THROUGH THE RIO
GRANDE RIVER BASIN BEFORE TURNING INTO THE FRONTAL ZONE.  OVERALL
CONVECTIVE PATTERN IN IR/RADAR DOES NOT LOOK OVERLY IMPRESSIVE...
THIS IS DUE TO WARMING IN THE UPPER LEVELS FROM THE OUTFLOW OF
PATRICIA...AND LOWER EQUILIBRIUM LEVELS AND TOPS.  STILL
SURROUNDING 00Z RAOBS (CRP/BRO/SHV/AND MODIFIED DRT) ALL STRONGLY
SUGGEST WITH SATURATION BELOW 400 MB AND NEARLY IDENTICAL WBZ/FGZ
LEVELS WITH TPWS OVER 2" AND AMPLE CAPES TO 1000-2000 J/KG WHETHER
SURFACE BASED OR ELEVATED...ALL SUPPORT HIGHLY EFFICIENT RAINFALL
PROCESSES...WITH RATES OF 2-2.5"/HR...POTENTIALLY 3" AT
AFOREMENTIONED INCREASED CONVERGENCE POINTS. 

NORTHEAST ALONG THE BOUNDARY...INSTABILITIES ARE WASHED OUT A BIT
AND THUNDERSTORMS HAVE GIVEN WAY TO HIGHLY EFFICIENT OVERRUNNING
STRATIFORM WITH ISOLATED FRACTURED CONVECTIVE CORES ALONG THE
FRONTAL ZONE.  

LATER THIS MORNING...SECONDARY COLD FRONT WILL CONTINUE TO DRAW
SOUTHEAST WITH THE POTENTIAL FOR A SECONDARY LINE TO DEVELOP AND
EXPAND THE NORTHWEST EXTENT OF POTENTIAL HEAVY RAIN WITHIN THE
SOUTHWEST TRAINING PROFILE.  STRONGER SURFACE WINDS DRAINING JUST
OFF THE HIGHER TERRAIN HAVE THE POTENTIAL TO DRIVE THE WESTERN
EXTENT OF STATIONARY FRONT SOUTH WITH ITS MERGER DEVELOPING A WEAK
SURFACE WAVE JUST NORTH OF 30N AND EAST OF 100W...THOUGH THIS
WOULD BE TOWARD THE END OF THIS DISCUSSION PERIOD.  

GALLINA

ATTN...WFO...EWX...FWD...HGX...MAF...OUN...SHV...SJT...

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

LAT...LON   33839711 33819639 33809570 33809523 33649418 
            32799321 32179371 31139645 30669810 30040094 
            29860132 29850222 30210230 31040115 31820009 
            32290041 32680028 33119960 33689810