MESOSCALE PRECIPITATION DISCUSSION 0284
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1049 AM EDT SUN AUG 17 2014
 
AREAS AFFECTED...NORTHERN MS...NORTHERN AL...CENTRAL TN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 171448Z - 171848Z
 
SUMMARY...A DEVELOPING LINE OF STRONG THUNDERSTORMS WITH VERY
HEAVY RAIN HAS DEVELOPED ALONG A MID-LEVEL BOUNDARY ACROSS
NORTHERN MS AND CENTRAL TN.  GIVEN THAT THE SOUTHERN PORTION OF
THIS LINE OF CONVECTION IS SLOW MOVING, FLASH FLOODING IS POSSIBLE.

DISCUSSION...RECENT DEVELOPMENT OF CONVECTION ACROSS WESTERN TN
AND INTO NORTHERN MS NEAR A 700MB THETA-E GRADIENT HAS SHOWN
LITTLE SOUTHEASTWARD PROGRESSION OVER THE PAST HOUR.  THIS IS
CAUSING SOME CELL TRAINING ACROSS THIS REGION, AND SOME LOCATIONS
HAVE ALREADY RECEIVED IN EXCESS OF TWO INCHES PER RADAR ESTIMATES
SINCE 8 AM LOCAL TIME, WITH FLASH FLOOD GUIDANCE VALUES NEAR THREE
INCHES OVER A 3-HOUR TIME PERIOD.  A WSW 850MB INFLOW OF 20 TO 30
KTS IS ADVECTING 1.75 TO 2.00IN PWS INTO THIS REGION.  

THE EXPECTATION IS FOR CELL TRAINING ACROSS NORTHERN MS AND AL,
AND INTO TENNESSEE OVER THE NEXT SEVERAL HOURS.  THE MAJORITY OF
THE MESOSCALE QPF IS CURRENTLY DEPICTING LIGHTER RAINFALL THAT
WHAT IS OCCURRING.  HOURLY RAINFALL RATES OF UP TO 2.5 INCHES PER
HOUR ARE SUPPORTED FROM THE HIGH PW VALUES, WHICH COULD LEAD TO 2
TO 4 INCHES OF RAINFALL WHERE CELLS ARE TRAINING.  

HAMRICK

ATTN...WFO...OHX...BMX...HUN...MEG...JAN...LZK...

ATTN...RFC...ABRFC...LMRFC...OHRFC...SERFC...WGRFC...

LAT...LON   33769156 34319109 34829006 35288907 35758818 35948752
            35898698 35638648 35078614 34728616 34278655 33598763
            33148875 33018989 32979088 33139148 33769156