MESOSCALE PRECIPITATION DISCUSSION 0291
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
536 PM EDT MON AUG 18 2014
 
AREAS AFFECTED...SOUTHERN TN/NORTHEASTERN MS/NORTHERN AL/NORTHWEST
GA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 182135Z - 190200Z
 
SUMMARY...THERE IS A CONTINUED RISK OF FLASH FLOODING OVER PARTS
OF TN/NORTHERN AL INTO NORTHWEST GA AS AN MCV FROM OVERNIGHT
CONVECTION WORKS ITS WAY INTO A MOIST AND UNSTABLE AIRMASS.  

DISCUSSION...ONE AREA OF CONVECTION WHICH HAS ALREADY PRODUCED
SOME HEAVY RAINFALL OVER SOUTHERN TN WILL BE MOVING EAST WHILE
MORE COVECTION SHOULD DEVELOP IN RESPONSE TO THE APPROACH OF A MID
LEVEL VORTICITY CENTER SPUN UP BY CONVECTION LAST NIGHT AND EARLY
THIS MORNING.  

SUPER RAPID SCAN IMAGERY CONTINUES TO SHOW THAT MOST OF THE MOST
ACTIVE UPDRAFTS WERE LOCATED FROM SOUTH CENTRAL TN INTO NORTHERN
AL...A REGION WHERE THE MEAN MID LEVEL FLOW WAS ROUGHLY THE SAME
AS LOW LEVEL INFLOW.  MUCAPE VALUES FROM THE HRRR WERE ABOVE 2000
J PER KG ACROSS THE REGION AND LOW LEVEL MIXING RATIOS REMAINED IN
THE 16 TO 18 G PER KG RANGE.  VALUES ARE NOT EXPECTED TO CHANGE
MUCH THROUGH AROUND 19/00Z SO THE POTENTIAL EXISTS FOR ANOTHER
ROUND OF MDT TO HEAVY RAINFALL INTO THE EVENING.  IN SOME CASES
THAT RAIN WILL FALL ON AREAS WHICH ALREADY RECEIVED RAINFALL AND
HAVE A CORRESPONDINGLY LOWER FLASH FLOOD GUIDANCE. 

BANN

ATTN...WFO...BMX...FFC...HUN...MEG...MRX...OHX...

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

LAT...LON   35818667 35748497 35218427 34528438 34308551 
            33438682 34278844 34788879 35218843