MESOSCALE PRECIPITATION DISCUSSION 0313
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
740 AM EDT FRI JUN 09 2017

AREAS AFFECTED...NORTH CENTRAL TX

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 091140Z - 091640Z

SUMMARY...ISOLATED FLASH FLOOD ISSUES MAY CONTINUE INTO MID
MORNING.

DISCUSSION...A COMPLEX OF THUNDERSTORMS CONTINUES TO SLOWLY PUSH
SOUTHEASTWARD ACROSS NORTH CENTRAL TEXAS THIS MORNING. SOME
UNCERTAINTY WITH REGARDS TO HOW LONG THIS ACTIVITY IS ABLE TO
PERSIST...WITH WEAKENING EVENTUALLY EXPECTED. CONVECTION IS
ELEVATED IN NATURE...BEING FORCED IN PART BY LOW LEVEL MOISTURE
CONVERGENCE AND UPPER LEVEL DIVERGENCE ASSOCIATED WITH A SUBTLE
SHORTWAVE FEATURE AND DIFFLUENT FLOW ALOFT. CURRENTLY ANTICIPATE
THAT THESE FORCING MECHANISMS WILL PERSIST FOR AT LEAST THE NEXT
COUPLE OF HOURS...WITH UPPER LEVEL SUPPORT APPEARING TO WANE SOME
AFTER 16Z OR SO...AND LOW LEVEL MOISTURE TRANSPORT LIKELY TO
DECREASE SOME AS WELL AS DIURNAL HEATING BEGINS TO MIX OUT THE
BOUNDARY LAYER. RECENT RAP ANALYSIS ALSO SHOWS AN INCREASING TREND
IN MUCAPE JUST DOWNSTREAM OF THE CURRENT CONVECTIVE AREA...ALSO
SUGGESTING IT MAY BE ABLE TO PERSIST FOR AT LEAST A COUPLE MORE
HOURS. LATEST IR IMAGERY DOES SHOW SIGNS OF WARMING CLOUD TOPS
OVER OK...BUT THE SCATTERED REDEVELOPMENT OVER NORTH TEXAS APPEARS
TO BE MAINTAINING ITSELF FOR NOW.

THUS WOULD APPEAR THAT THE OPERATIONAL HRRR MAY BE WEAKENING THE
ACTIVITY A BIT TOO QUICKLY...WITH AN OUTCOME CLOSER TO THE 0Z NSSL
WRF AND 06Z EXPERIMENTAL HRRR MORE PROBABLE. LOW LEVEL FLOW
GENERALLY OPPOSITE TO CORFIDI VECTORS AND STORM PROPAGATION
CONTINUES TO SUPPORT SOME BACKBUILDING AND BRIEF TRAINING OF CELLS
AS THE COMPLEX SHIFTS SOUTH. THUS POCKETS OF AROUND 2" IN AN HOUR
AMOUNTS...AND 2-4" TOTALS IN A THREE HOUR PERIOD APPEAR LIKELY TO
CONTINUE. THESE AMOUNTS MAY LOCALLY BEGIN TO CHALLENGE FLASH FLOOD
GUIDANCE VALUES. THUS WHILE WIDESPREAD FLOODING ISSUES ARE NOT
EXPECTED TO DEVELOP...LOCALIZED ISSUES...ESPECIALLY IN MORE
SUSCEPTIBLE AND URBAN AREAS...WILL CONTINUE.

CHENARD

ATTN...WFO...FWD...

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

LAT...LON   33479748 33399668 32739609 32259591 31439596
            30909658 31029740 31939836 32539839 33179807