MESOSCALE PRECIPITATION DISCUSSION 0371
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
804 PM EDT THU JUN 22 2017

AREAS AFFECTED...NORTHERN & CENTRAL LA...SOUTHERN AR...EXT
SOUTHEAST TX

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 230005Z - 230505Z

SUMMARY...INCREASING CONFLUENCE ALONG SOUTHERN BAND ALONG WITH
IMPROVING UNIDIRECTIONAL PROFILES SUPPORTING TRAINING POSE
INCREASING FLASH FLOOD THREAT IN EARLY OVERNIGHT HOURS.

DISCUSSION...TROPICAL DEPRESSION CINDY CONTINUES TO SLOWLY DECAY
WITH MID TO UPPER LEVEL FLOW REGIME SUPPORTING INCREASING
STRETCHING/ELONGATION OF THE INNER CORE FROM SW TO NE.  THIS IS
ALSO STARTING TO MANIFEST TOWARD THE SURFACE AS WELL AS THE INNER
SURFACE LOW FILLS...CONVECTIVE PROCESSES ARE SUPPORTING INCREASED
OUTFLOW FROM THE OLD OCCLUSION HAS PRESSED EASTWARD ACROSS NORTH
CENTRAL LA BECOMING CONVERGENT WITH SW TO NE ORIENTED OUTER BAND. 
ONSHORE MOIST/UNSTABLE FLOW HAS BEEN STRENGTHENING OVER THE PAST
HOUR OR SO WITH INCREASING CONVERGENCE ALONG THIS BAND AS EVIDENT
IN VIS/EIR WITH NORTHWARD TILTING CONVECTIVE TOWERS DEVELOPING
ACROSS LA; HOWEVER WITH AFOREMENTIONED STRETCHING ALOFT SHEAR IS
REDUCING ALLOWING FOR INCREASED VERTICAL GROWTH AS NOTED IN SE TX
ATTM.  INCREASED VERTICALITY AND DEEPER WARM CLOUD RAINFALL
GENERATION PROCESSES TAPPING VERY DEEP/MOIST LOWER PROFILES WITH
TPWS AROUND 2.5" WILL SUPPORT BETTER RATES LIKELY REACHING 2 TO
2.5"/HR IMPROVING WITH TIME. THE BAND WILL ALSO ORIENT FAVORABLY
WITH THE FLOW TO SUPPORT TRAINING OF CELLS ACROSS CENTRAL LA WITH
THE BEST THREAT TOTALS IN THE 2-4" RANGE WITH LOCALIZED TOTALS UP
TO 5" EVEN SUGGESTED BY THE HRRRX AND DOWNWARD ADJUSTED
NAM-CONEST.  ADDITIONALLY TO REACH THESE SORTS OF TOTALS...850MB
WILL BE STRENGTHENING/CONFLUENT WITH WINDS TO 40-45KTS SUPPORTING
UPSTREAM PROPAGATION VECTORS (BACKBUILDING).

GIVEN AREA FROM VERNON TO LA SALLE/ CATAHOULA PARISH HAS BEEN
SPARED FROM EARLIER BOUTS ASSOCIATED WITH CINDY WITH FFG VALUES
REMAINING AT NORMAL LEVELS...IT IS INCREASING CONFIDENCE THERE
WILL BE EXCEEDANCE OF 2-3" IN 3HRS AND AS SUCH FLASH FLOODING IS
CONSIDERED LIKELY.

NEARER THE INNER CORE OF CINDY...THERE IS AN UPTICK IN LOW LEVEL
CONVERGENCE AND CONVECTION DEVELOPMENT.  WHILE SOURCE OF
INSTABILITY WILL BE LESS THAN FURTHER SOUTH...MOISTURE IS A BIT
DEEPER OVER 2.5" IN TPW AND THEREFORE CONVECTION POSES A POSSIBLE
THREAT FOR FF AS IT LIFTS NNE TOWARD S AR BY 06Z AND THEREFORE IS
INCLUDED IN THE FF THREAT/MPD AREA OF CONCERN...THOUGH THE
POTENTIAL IS A BIT LESS WITH 1-3" MORE THE NORM. 

GALLINA

ATTN...WFO...JAN...LCH...LZK...SHV...

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

LAT...LON   33809182 33369125 31969128 30719234 30039406
            30139443 30529446 31699388 33019392 33679324