MESOSCALE PRECIPITATION DISCUSSION 0603
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
601 AM EDT FRI OCT 23 2015
 
AREAS AFFECTED...E TEXAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 231000Z - 231600Z
 
SUMMARY...INCREASING TRAINING CONVECTION ON N-S BOUNDARY...TO
INTERSECT/MERGE WITH ONGOING CONVECTION ACROSS NE TEXAS.

DISCUSSION...ONGOING WEDGE OF CONVECTION WITHIN DIFFLUENT UPPER
LEVEL FLOW SEEN IN IR SATELLITE LOOP CROSSING DALLAS/FORT WORTH
METRO ATTM (PLEASE SEE 0741Z SPENES FROM NESDIS FOR MORE DETAILS)
CONTINUES WITH STRONG UVVS FROM RIGHT ENTRANCE DYNAMICS AND
CONTINUED LOW LEVEL MOISTURE CONVERGENCE ALONG INTERFACE OF 30KT
LLJ AND SW TO NE STALLED STATIONARY FRONT.  A GENERAL LULL IN THE
UPPER-LEVEL SUPPORT BETWEEN WEAK WAVES HAS REDUCED BACKBUILDING OF
THE CONVECTION OVER THE PAST FEW HOURS.  HOWEVER...WITH SURGE OF
WAA AND FRICTIONAL CONVERGENCE ZONE ALONG THE COASTLINE OF THE NW
GULF OF MEXICO IS ACTIVATING NEW CONVECTION THAT IS REMAINS
FOCUSED AND ENHANCED ALONG N-S CONFLUENCE/ DEEP MOISTURE
CONVERGENCE BOUNDARY.  GENERALLY THE CLOUD BARRING LAYER OF THE
CELLS IS DEEPLY UNIDIRECTIONAL FROM THE SOUTH...SO CELLS WILL
GENERALLY TRAIN OVER THE SAME CORRIDOR FROM JACKSON TO LIMESTONE
COUNTY OVER THE NEXT FEW HOURS.   ADDITIONAL UVV SUPPORT IS GIVEN
IN THE LEFT EXIT OF 70 KT SUBTROPICAL JET AXIS/OUTFLOW CHANNEL
FROM HURRICANE PATRICIA.  THIS SHOULD INCREASE VERTICAL DEPTH AND
RAINFALL EFFICIENCY OF THE CELLS AS THEY PROGRESS NORTHWARD ALONG
THE BOUNDARY. GIVEN DEEP MOIST ENVIRONMENT WITH TPWS RANGING FROM
2.25" ALONG THE GULF COAST TO 2.0" NEAR DAL/FTW AREA INTO SE
OKLAHOMA WILL SUPPORT RATES OF 1.5-2.0"/HR WITH POTENTIALLY HIGHER
IF CONVECTION CAN BECOME DEEPER AND MORE ROBUST BY 12Z. OVERALL
LIMITING FACTOR FOR FLASH FLOODING IS THE HIGH FFG WITHIN THE AREA
OF CONCERN...THOUGH WITH SATURATED SOILS OVER NE TEXAS THE THREAT
IS OBVIOUSLY HIGHER THERE...EVEN THOUGH THE TOTALS MAY BE LESS
THAN WITHIN THE N-S TRAINING CORRIDOR. 

HI-RES CAMS SUCH AS THE OLD 12Z WRF-NSSL AND GEM REGIONAL ALONG
WITH RECENT RUNS OF THE HRRR SUPPORT THIS CHANNEL OF TRAINING
CELLS MERGING WITH CELLS ALONG THE FRONTAL BOUNDARY.

GALLINA

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

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

LAT...LON   33819595 33659475 33409410 32309440 31489552 
            30819562 29869548 28929560 28669594 28509675 
            30019727 31839754 32969699