MESOSCALE PRECIPITATION DISCUSSION 0484
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
237 PM EDT THU JUL 19 2018

AREAS AFFECTED...CENTRAL MISSISSIPPI

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 191837Z - 192145Z

SUMMARY...OVER 2"/HR RATES AND SLOW MOTIONS MAY LEAD TO ISOLATED
FLASH FLOODING.

DISCUSSION...OUTFLOW BOUNDARY FROM OLD MCS COMPLEX ALONG AL/MS
BORDER SLOWLY PROGRESSES WEST FROM YALOBUSHA TO N SCOTT COUNTY. 
GPS PW AND BLENDED TPW IMAGERY SHOWS AN AXIS OF DEEPER MOISTURE
COINSIDENT WITH THIS BOUNDARY WITH VALUES NEAR OR ABOVE 2.25". 
STRONG DIABATIC HEATING HAS SUPPORTED MLCAPES TO EXCEED 2500 J/KG
WHICH ARE FAIRLY STATURATED TO 4H SUPPORTING STRONG UPDRAFTS AND
EXCELLENT RAIN GENERATION. 12Z SOUNDING FROM JAN SUGGESTS ONLY A
SMALL FGZ-WBZ LAYER OF ABOUT 1000 FT BUT WELL ABOVE 14KFT
SUPPORTING A LARGE DEPTH OF WARM CLOUD PROCESS AND HIGH RAINFALL
EFFICIENCY.  UPDRAFTS APPEAR A BIT NARROW GIVEN WEAK INFLOW/FLUX
FROM LOW LEVELS (LESS THAN 10KTS) BUT ALSO SUPPORT STRONG UP/DOWN
COUPLET FOR HIGH RAINFALL TOTALS/EFFICIENCY IN SHORT DURATION WITH
2-2.5" HOURLY TOTALS POSSIBLE.  GIVEN SLOW WESTWARD
PROPAGATION...THERE IS SOME POSSIBILITY FOR NEW UPDRAFTS TO BE
CLOSE ENOUGH IN PROXIMITY TO SUPPORT SOME SECONDARY BURSTS OVER
SIMILAR DRAINAGE BASINS.  AS SUCH FF IS CONSIDERED POSSIBLE FOR
THE NEXT FEW HOURS IN THIS REGION. 

GALLINA

ATTN...WFO...JAN...MEG...

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

LAT...LON   34328941 34008929 33138923 32428917 32358973
            32848989 34018998 34298986