Graphic for MPD #0611

MESOSCALE PRECIPITATION DISCUSSION 0611
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
846 PM EDT MON JUL 31 2017

AREAS AFFECTED...CENTRAL AND SOUTHERN FL

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

VALID 010030Z - 010500Z

SUMMARY...BANDING ASSOCIATED WITH EMILY COULD POSE A FLASH FLOOD
THREAT ACROSS PORTIONS OF CENTRAL AND SOUTHERN FL THROUGH THE
EARLY MORNING HOURS.

DISCUSSION...CONVECTION IN THE BANDING FEATURE FORMING IN THE
CONFLUENT LOW LEVEL FLOW SOUTH OF THE CENTER OF TROPICAL
DEPRESSION EMILY IS STARTING TO INCREASE IN THE STRENGTH AND
COVERAGE...CROSSING THE COAST FROM BETWEEN FMY AND APF. THE KMLB
RADAR SHOWED HOURLY RAINFALL RATES WITH THE ASSOCIATED BANDING
BETWEEN 1.00 AND 1.50 INCHES...BUT EARLIER RADAR ESTIMATES WITH
CONVECTION ASSOCIATED WITH EMILY WHERE AS MUCH AS 50 PERCENT TOO
LOW. THIS IS NOT SURPRISING...GIVEN THE TROPICAL AIRMASS IN PLACE.

ONLY THE 22Z HRRR (AND TO COME EXTENT THE 18Z NAM CONUS NEST) HAD
A DECENT HANDLE ON THE BANDING THAT HAS DEVELOPED. THE HRRR SHOWED
THAT BANDING OCCURRING PRESENTLY TO DROP SOUTH INTO SOUTHERN FL AS
THE BEST LOW LEVEL CONVERGENT FLOW DROPS SOUTH.

AS EMILY MOVES SLOWLY EASTWARD THROUGH THE OVERNIGHT...LOCAL 3.00
TO 5.00 INCH RAINFALL AMOUNTS CAN BE EXPECTED WITH THE BANDING
FEATURES. THIS SEEMS REASONABLE BASED ON WHAT HAPPENED EARLIER...
AND IS REFLECTED IN THE 22Z HRRR RAINFALL.

THE BANDING WILL TRACK OVER AREAS THAT RECEIVED HEAVY RAINFALL
EARLIER...AND COULD INITIATE FLASH FLOODING...ESPECIALLY IN URBAN
AREAS AND POORLY DRAINED LOCATIONS THIS EVENING INTO THE EARLY
OVERNIGHT.

HAYES

ATTN...WFO...MFL...MLB...TBW...

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

LAT...LON   27628123 27458040 26818001 25888003 25248045
            25228113 25428140 25848172 26688222 27178228
            27508186


Last Updated: 846 PM EDT MON JUL 31 2017