MESOSCALE PRECIPITATION DISCUSSION 0378
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
542 AM EDT FRI JUN 23 2017
AREAS AFFECTED...NORTHERN LA
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 230941Z - 231411Z
SUMMARY...THUNDERSTORMS ARE EXPANDING IN COVERAGE WITHIN THE
SOUTHWEST QUADRANT OF TROPICAL DEPRESSION CINDY. HOURLY RAIN
RATES TO 2.5" WITH LOCAL AMOUNTS TO 5" ARE POSSIBLE.
DISCUSSION...THERE HAS BEEN A SLOW UPTICK TO RAINFALL RATES WITH
CONVECTION OVER THE PAST COUPLE HOURS NEAR NATCHITOCHES LA.
PRECIPITABLE WATER VALUES OF ~2.5" LIE ACROSS THE REGION, AND
THUNDERSTORMS ARE DEVELOPING DOWNWIND OF AN INSTABILITY GRADIENT
NEAR THE TX/LA BORDER. INFLOW AT 850 HPA IS CONVERGENT AT 25-40
KTS.
THE MESOSCALE GUIDANCE HAS BEEN ADVERTISING THIS ACTIVITY TO FORM
THROUGHOUT THE NIGHT, AND IT HAS FINALLY OCCURRED. THE MORE
RELIABLE GUIDANCE SUGGESTS TOTALS NEAR 5", WHICH IS PLAUSIBLE.
MUCH OF THE AREA HAS RECEIVED MINIMAL RAINFALL FROM CINDY SO FAR
SO FLASH FLOOD GUIDANCE VALUES ARE RATHER HIGH. THE HIGH FLASH
FLOOD GUIDANCE KEPT THE CATEGORY AS POSSIBLE.
ROTH
ATTN...WFO...JAN...LCH...SHV...
ATTN...RFC...LMRFC...WGRFC...
LAT...LON 33059129 33049121 32099110 31439185 31189343
32279411 33049398 33049234
Last Updated: 542 AM EDT FRI JUN 23 2017