MESOSCALE PRECIPITATION DISCUSSION 0304
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
452 PM EDT FRI JUN 03 2016
 
AREAS AFFECTED...PORTIONS OF LA & MS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 032051Z - 040251Z
 
SUMMARY...THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE REGION
OVER THE NEXT SEVERAL HOURS.  WITH CELL TRAINING POSSIBLY BRINGING
HOURLY RAIN RATES UP TO 2.25", FLASH FLOODING IS POSSIBLE.

DISCUSSION...AN AREA OF SHOWERS AND THUNDERSTORMS WITH COOLING
TOPS SEEN ON RECENT INFRARED SATELLITE IMAGERY IS MOVING EASTWARD
FROM THE 91ST MERIDIAN INTO SOUTHEAST LA AND MS.  PRECIPITABLE
WATER VALUES ARE NEAR 2" PER GPS VALUES.  INFLOW AT 850 HPA OF
20-30 KTS IS IMPORTING MLCAPES OF 2000-2500 J/KG INTO THE REGION. 
THE AREA HAS BEEN MOVING EAST AT ~15 KTS INTO AN REGION THAT HAS
NOT SEEN WIDESPREAD HEAVY RAINS OVER THE PAST COUPLE WEEKS, PER
SOUTHERN REGION PRECIPITATION ESTIMATES.

LOW-LEVEL INFLOW IS EXPECTED TO BACK SLIGHTLY WITH TIME, WHICH
COULD RETARD THE FORWARD PROGRESSION OF THE THUNDERSTORM AREA. 
THE MESOSCALE/CAM GUIDANCE, WHICH APPEARS SOMEWHAT SLOW WITH THE
FORWARD MOVEMENT OF THE CONVECTIVE REGION, HAS A SIGNAL FOR LOCAL
AMOUNTS OF 2-4".  THE RAIN COULD FALL QUICKLY, AS CELL TRAINING
CAUSED BY THE FAIRLY UNIDIRECTIONAL SOUTHERLY FLOW COULD LEAD TO
HOURLY RAIN RATES UP TO 2.25".  THIS INTENSITY OF RAIN COULD
CHALLENGE FLASH FLOOD GUIDANCE VALUES AND WOULD LEAD TO ISSUES IN
URBAN AREAS.  THE 12Z SSEO NEIGHBORHOOD PROBABILITIES IMPLY ISSUES
COULD PERSIST UNTIL 02Z, THOUGH AVAILABLE INSTABILITY AND MOISTURE
IMPLIES ISSUES ARE POSSIBLE TOWARDS 03Z.

ROTH

ATTN...WFO...JAN...LCH...LIX...LZK...MEG...MOB...SHV...

ATTN...RFC...LMRFC...SERFC...

LAT...LON   34098935 32398881 30008878 28818934 29138993 
            28919075 28969182 30559149 32179156 33189224 
            33959064