Graphic for MPD #0449

MESOSCALE PRECIPITATION DISCUSSION 0449
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
902 AM EDT THU JUL 06 2017

AREAS AFFECTED...SRN/SERN AR INTO WRN MS

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

VALID 061300Z - 061600Z

SUMMARY...FLASH FLOODING RAINFALL MAY CONTINUE FOR THE NEXT COUPLE
OF HOURS FROM SRN/SERN AR INTO NWRN MS. AN ADDITIONAL 2-4 INCHES
WILL BE POSSIBLE.

DISCUSSION...EXPERIMENTAL GOES 16 IR IMAGERY SHOWED A LINGERING
AREA OF COLDER CLOUD TOPS OVER OUACHITA AND CALHOUN COUNTIES IN
SRN AR WHILE LOCATIONS TO THE NORTH WERE EXPERIENCING SIGNIFICANT
WARMING/WEAKENING AS OF 1230Z. THE AREA OF CONVECTION IS OCCURRING
WITHIN AN AXIS OF 850 MB CONVERGENCE FOCUSED WEST TO EAST OVER SRN
AR...AHEAD OF A POSITIVELY TILTED SHORTWAVE TROUGH AXIS EXTENDING
SW TO NE THROUGH NWRN AR. IN ADDITION...SOME DEGREE OF SUPPORT FOR
LIFT IS LIKELY TIED TO THE RIGHT ENTRANCE REGION OF A 50 KT UPPER
LEVEL JET LOCATED OVER NRN AR.

RAP FORECASTS SHOW THE AREA OF 850 MB CONVERGENCE WEAKENING
THROUGH 16Z WHILE ALSO TRANSLATING DOWNSTREAM INTO NRN MS AHEAD OF
THE ADVANCING SHORTWAVE TROUGH AXIS. DESPITE SOME RECENT WARMING
OF CLOUD TOPS OVER OUACHITA AND CALHOUN COUNTIES...LIKELY DUE TO
WANING INSTABILITY...RELATIVELY HIGHER MUCAPE EXISTS ACROSS NRN
MS...ESTIMATED IN THE 500-1000 J/KG RANGE AND EVEN HIGHER TO THE
SOUTH WHERE 12Z SOUNDINGS FROM SHV AND JAN SHOWED OVER 2000 J/KG
CAPE. THE POTENTIAL FOR RENEWED CONVECTION WITH RAINFALL RATES OF
1-2 IN/HR ALONG WITH TRAINING PER NEARLY STATIONARY OR BACKWARD
PROPAGATING CORFIDI VECTORS SUGGESTS THE FLASH FLOOD THREAT WILL
LINGER FOR ANOTHER 2-3 HOURS FROM SRN/SERN AR INTO NWRN MS.

OTTO

ATTN...WFO...JAN...LZK...MEG...SHV...

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

LAT...LON   34968929 34768858 34198898 33369113 33169291
            33699281 34229163 34739018


Last Updated: 902 AM EDT THU JUL 06 2017