MESOSCALE PRECIPITATION DISCUSSION 0352
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
807 AM EDT WED JUN 21 2017

AREAS AFFECTED...SOUTHERN MS...SOUTHERN AL...WESTERN FL PANHANDLE

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

VALID 211200Z - 211800Z

SUMMARY...ADDITIONAL BANDS OF HEAVY RAIN WILL CONTINUE TO IMPACT
THE CENTRAL GULF COAST REGION THIS MORNING. THIS WILL COMPOUND
ONGOING FLASH FLOODING CONCERNS.

DISCUSSION...EXPERIMENTAL GOES-16 10.3 MICRON/IR IMAGERY CONTINUES
TO SHOW BANDS OF STRONGER CONVECTION ADVANCING NORTH-NORTHWEST IN
OFF THE NORTHERN GULF OF MEXICO AND ACROSS THE CENTRAL GULF COAST
REGION IN ASSOCIATION WITH THE EASTERN FLANK OF THE CIRCULATION
ASSOCIATED WITH T.S. CINDY. AREA RADARS SHOW THE STRONGEST
ACTIVITY AGAIN IMPINGING ON THE WESTERN FL PANHANDLE...WITH SOME
BROKEN AREAS OF STRONGER CONVECTION ALSO SEEN FARTHER WEST OVER
SOUTHERN MS. FARTHER NORTH OVER AREAS OF MS/AL AWAY FROM THE COAST
THERE IS A SHIELD OF MODERATE TO LOCALLY HEAVY STRATIFORM RAIN.

DEEP LAYER SOUTH-SOUTHEAST FLOW AROUND THE EAST SIDE OF T.S. CINDY
WILL CONTINUE TO FAVOR AN ENVIRONMENT CONDUCIVE FOR FOCUSED BANDS
OR CLUSTERS OF VERY HEAVY RAIN/THUNDERSTORMS ACROSS THE CENTRAL
GULF COAST REGION THROUGH MIDDAY AS A WELL-DEFINED WARM CONVEYOR
BELT AND FOCUSED AXIS OF MOISTURE/INSTABILITY TRANSPORT PERSISTS
OVER THE REGION.

FACILITATING THE THREAT FOR STRONGER CONVECTION AND HEAVIER
RAINFALL RATES WILL BE THE PROXIMITY OF WHAT APPEARS TO BE A WEAK
SURFACE FRONT/TROUGH EXTENDING FROM SOUTHEAST LA EAST ACROSS THE
IMMEDIATE COASTAL AREAS OF MS/AL AND THE FL PANHANDLE. SOME OF THE
HEAVIEST RAINS THROUGH MIDDAY WILL LIKELY BE NEAR AND JUST NORTH
OF THIS BOUNDARY WHERE THE INSTABILITY GRADIENT IS MOST
PRONOUNCED. FARTHER NORTH... THE RAINFALL IS LIKELY TO TEND TO BE
A BIT MORE STRATIFORM WITH AN ISENTROPIC ASCENT PATTERN FAVORING
STEADY MODERATE TO HEAVY RAIN.

THE LATEST HRRR/HRRRX GUIDANCE SUGGESTS AS MUCH AS AN ADDITIONAL 3
TO 6 INCHES OF RAIN THROUGH 18Z...WITH THE HEAVIEST TOTALS LIKELY
SETTING UP FOR AREAS OF SOUTHERN AL AND THE WESTERN FL PANHANDLE.
SOMEWHAT LESSER AMOUNTS THIS PERIOD OVER SOUTHERN MS. THESE
ADDITIONAL RAINS ARE EXPECTED TO EXACERBATE THE FLASH FLOODING
POTENTIAL AND WITH LOCALLY SIGNIFICANT RUNOFF PROBLEMS LIKELY.
WILL CONTINUE TO MONITOR.

ORRISON

ATTN...WFO...JAN...LIX...MOB...TAE...

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

LAT...LON   32258929 31948792 31538693 30938581 30418534
            30058551 30118615 30178656 30238750 30248865
            30298960 30779020 31309038 31829042 32169001