MESOSCALE PRECIPITATION DISCUSSION 0503
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
843 PM EDT FRI JUL 29 2016
 
AREAS AFFECTED...WESTERN AND CENTRAL TN 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 300045Z - 300400Z
 
SUMMARY...CONVECTION TAKING ON A WEST TO EAST ORIENTATION ACROSS
PORTIONS OF WESTERN AND CENTRAL TN COULD RESULT IN A SHORT TERM
FLASH FLOOD THREAT THROUGH LATE THIS EVENING.

DISCUSSION..REGIONAL RADARS SHOWED CONVECTION AHEAD OF A WEAK
SHORT WAVE OVER WESTERN MO TAKING ON A WEST TO EAST ORIENTATION
ACROSS PORTIONS OF WESTERN AND CENTRAL TN...ALONG AN AXIS OF
1500-2000 J/KG MLCAPE...AS WELL AS 1.80 INCH PRECIPITABLE WATER
AIR. FOR THE MOST PART...THE CONVECTION HAD BEEN OUTFLOWED
DOMINATED...BUT THE REORIENTATION OF THE CONVECTION HAS RESULTED
IN HOURLY RAINFALL RATES BETWEEN 2.00 AND 3.00 INCHES...BASED ON
THE KNQA RADAR. 

TOPS HAVE BEEN COOLING STEADILY WITH THIS FEATURE...WITH CLOUD TOP
TEMPERATURES AS COLD AS -71 C. GIVEN THE STRUCTURE ON SATELLITE
AND RADAR...IT APPEARS AS THOUGH THE CONVECTION SHOULD MAINTAIN
ITS STRENGTH INTO THE EVENING HOURS...BEFORE THE INSTABILITY
BECOMES EXHAUSTED AFTER 04Z (PER THE LATEST RAP).  

NONE OF THE MOST RECENT HIGH RESOLUTION GUIDANCE IS HANDLING THE
CONVECTION WELL...WITH THE LATEST HRRR/HRRR PARALLEL TOO SLOW WITH
THE CONVECTION (BY 2 OR 3 HOURS...BASED ON THE QPF AND SIMULATED
REFLECTIVITY). BOTH OF THESE SOLUTIONS INDICATE THAT 2-4 INCHES OF
RAINFALL IS POSSIBLE WITH THE CONVECTION...ESPECIALLY WHERE
TRAINING OCCURS. THIS IS MOST LIKELY ACROSS SOUTHERN SECTIONS OF
WESTERN AND CENTRAL TN...GENERALLY SOUTH OF AREA THAT RECEIVED
HEAVY RAINFALL FRI AFTERNOON. 

HAYES

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

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

LAT...LON   36338689 36188550 35478437 34968464 34908699 
            34878948 35478962 35928894