MESOSCALE PRECIPITATION DISCUSSION 0641
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
251 PM EST THU NOV 05 2015
 
AREAS AFFECTED...CENTRAL & NORTHEAST TX 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 051950Z - 060150Z
 
SUMMARY...THUNDERSTORMS WITH HEAVY RAINFALL ARE DEVELOPING ACROSS
CENTRAL TX, WHICH SHOULD MOVE INTO NORTHEAST TX OVER THE NEXT
SEVERAL HOURS. WITH HOURLY RAIN RATES TO 2.5", FLASH FLOODING IS
POSSIBLE, ESPECIALLY IN URBAN AREAS.

DISCUSSION...A COMPLEX PATTERN IS SEEN ACROSS THE LONE STAR STATE
THIS AFTERNOON.  A VARIETY OF SURFACE BOUNDARIES, BOTH SYNOPTIC IN
SCALE AND MESOSCALE, HAVE BEEN FORCED BY DIFFERENTIAL HEATING AND
AN UPPER TROUGH MOVING INTO THE REGION FROM THE WEST.  THE SPC
MESOANALYSIS INDICATES MLCAPES OF 1000-3000 J/KG ACROSS CENTRAL
AND SOUTHERN TX, WITH AREAS OF CIN REMAINING ACROSS PORTIONS OF
NORTHEAST AND SOUTHERN TX.  PRECIPITABLE WATER VALUES OF 2-2.3"
EXIST WITHIN THIS AREA, OVER THREE SIGMAS ABOVE THE MEAN FOR EARLY
NOVEMBER.  BROAD INFLOW AT 850 HPA OF 30-40 KNOTS IS SUBTLY
CONVERGING INTO THIS AREA, NEAR THE MAGNITUDE OF THE MEAN WIND. 
ABOVE THE BOUNDARY LAYER, THE FLOW IS NEARLY UNIDIRECTIONAL WITH
HEIGHT, FAVORING CELL TRAINING.  

THE EXPECTATION IS FOR A BAND OF THUNDERSTORMS TO DEVELOP OVER THE
NEXT SEVERAL HOURS BETWEEN CENTRAL AND NORTHEAST TX ALONG THE AXIS
OF HIGHEST MOISTURE CONTENT.  INDIVIDUAL CELLS SHOULD CONTINUE
MOVING NORTH-NORTHEAST AT 45 KTS, WITH MORE ORGANIZED ACTIVITY
TRACKING EAST-NORTHEAST AT 30-35 KTS ALONG THE LINES OF FORWARD
PROPAGATING CONVECTIVE VECTORS AND THE 1000-500 HPA THICKNESS
PATTERN.  A SECOND BAND OF SEVERE THUNDERSTORMS IS EXPECTED TO
MOVE IN FROM THE WEST, WHICH COULD ALSO LEAD TO HEAVY RAINFALL
PROBLEMS AS IT MOVES INTO AN ENVIRONMENT WITH GREATER MOISTURE,
AND COULD CAUSE CELL MERGERS WITH THE MORE EASTERN BAND THIS
EVENING.  THE CAM GUIDANCE ADVERTISES LOCAL AMOUNTS OF 3-5", WHICH
COULD FALL QUICKLY.  THE AVAILABLE MOISTURE SUPPORTS HOURLY RAIN
RATES UP TO 2.5"; WHERE CELLS MERGE, HOURLY RAIN RATES COULD REACH
3-4".  URBAN AREAS HAVE ISSUES WITH HOURLY RAIN RATES AS LOW AS
1.5".  FLASH FLOODING IS CONSIDERED POSSIBLE, PARTICULARLY WITHIN
URBAN AREAS.

ROTH

ATTN...WFO...EWX...FWD...HGX...OUN...SHV...TSA...

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

LAT...LON   34129436 33209344 32209386 30539610 29869740 
            29749808 30219827 31409817 32799760 33589672 
            34049581