Graphic for MPD #0363

MESOSCALE PRECIPITATION DISCUSSION 0363
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
730 AM EDT THU JUN 22 2017

AREAS AFFECTED...CENTRAL/SOUTHEAST AL...WESTERN FL PANHANDLE

CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY

VALID 221130Z - 221600Z

SUMMARY...A TRAINING AXIS OF HEAVY RAINFALL WILL CONTINUE OVER THE
NEXT SEVERAL HOURS. ADDITIONAL FLASH FLOODING IS EXPECTED.

DISCUSSION...EARLY MORNING EXPERIMENTAL GOES-16 10.3 MICRON/IR
IMAGERY SHOWS A TRAINING BAND OF RATHER COLD TOPPED CONVECTION
EXTENDING FROM PARTS OF THE WESTERN FL PANHANDLE NORTH UP ACROSS
SOUTHEAST AL. THE ACTIVITY CONTINUES TO BE FOCUSED WITHIN AN AXIS
OF RELATIVELY ENHANCED LOW TO MID LEVEL CONVERGENCE ASSOCIATED
WITH THE OTHERWISE DEEP LAYER SOUTHERLY FLOW ACROSS THE CENTRAL
GULF COAST STATES TO THE EAST OF THE CENTER OF T.S. STORM CINDY.
ALTHOUGH INSTABILITY IS QUITE MODEST...WITH ONLY 500 TO 1000 J/KG
OF CAPE...THE COLUMN IS EXTREMELY MOIST WITH PWATS OF 2.3 TO 2.5
INCHES AND REPRESENTATIVE OF A CLASSIC DEEP LAYER TROPICAL
AIRMASS. THE UPPER LEVEL FLOW PATTERN IS RATHER DIVERGENT TOO...SO
THE CONVECTION HAS BEEN GETTING SOME LARGER SCALE ASCENT TO
FACILITATE THIS CONVECTIVE BAND THIS MORNING.

EXTREMELY HEAVY RAINFALL RATES WILL CONTINUE TO BE POSSIBLE WITH
THIS BAND OF CONVECTION OVER THE NEXT FEW HOURS GIVEN THE DEEP
COLUMN OF TROPICAL MOISTURE AND STRONGER FORCING LEADING TO THE
COLD-TOPPED NATURE OF THE ACTIVITY. RAINFALL RATES MAY EXCEED 3
INCHES/HR LOCALLY WHERE THE STRONGER CORES SET UP.

OVERALL THIS CONVECTIVE BAND WILL TEND TO REMAIN IN A N/S TRAINING
MODE...WITH PERHAPS A GRADUAL EASTWARD SHIFT TOWARD LATE MORNING.
CONSEQUENTLY...THERE WILL LIKELY BE A RATHER NARROW AXIS OF VERY
HEAVY RAINFALL TOTALS WHICH THE HRRR AND ESPECIALLY THE HRRX
GUIDANCE SUPPORTS...ALTHOUGH THESE MODELS ARE A LITTLE TOO FAR
WEST WITH THEIR AXIS. EXTRAPOLATING A BIT FARTHER
EAST...ADDITIONAL RAINFALL AMOUNTS OF 3 TO 5 INCHES CANNOT BE
RULED OUT IN A VERY LOCALIZED NATURE. WILL CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...BMX...MOB...TAE...

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

LAT...LON   33368641 33318563 32748527 32188515 31248514
            30288530 29968558 30248605 31328611 32038632
            32778669


Last Updated: 731 AM EDT THU JUN 22 2017