MESOSCALE PRECIPITATION DISCUSSION 0302
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
218 AM EDT TUE JUN 06 2017

AREAS AFFECTED...SOUTHWEST FL

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

VALID 060630Z - 061100Z

SUMMARY...ISENTROPIC ASCENT IN DEEPLY MOIST/UNSTABLE ENVIRONMENT
WITH SOME TRAINING MAY POSE FLOODING CONCERN THIS MORNING.

DISCUSSION...GOES-E AND 16 3.9 SWIR CHANNEL DENOTES A SURFACE
SWIRL NEAR 27.5N 88.5W...WITH A BOUNDARY ACTING AS PSUEDO WARM
FRONT LIKELY REINFORCED BY SOME OUTFLOW EXTENDING SWWARD FROM TO
ABOUT 25N BEFORE TURNING NEARLY DUE EAST TOWARD S MONROE COUNTY
(AS SFC WINDS IN KEYS ARE SLY).  RAP/LOW LEVEL CLOUD TRACERS
SUGGEST 35-45KT SWLY FLOW FROM 850-7H PROVIDING STRONG ISENTROPIC
ASCENT OVER THE BOUNDARY...GIVEN SOURCE REGION TDS IN THE LOW 80S
AND MID-80S TEMPS AND MOIST ADIABATIC LAPSE RATES THERE IS
SUFFICIENT MUCAPES TO 2500-3000 J/KG.  SATURATED PROFILES WITH
SOME MODEST CONFLUENCE EAST OF 850 (ANTICYCLONIC KINK NOTED IN RAP
ANALYSIS NEAR FMY/APF) SUPPORTS STRONG CONVERGENCE/FLUX TO SUPPORT
TPWS OF 2.5".  ALL CONSIDERED RATES AT OR ABOVE 2.5-3"/HR ARE
POSSIBLE WITH DEEPEST CORES.  GOES-WV LOOP AND AMVS SUPPORTS
MODEST DIFFLUENCE EAST OF 85W FURTHER STRENGTHENING ENVIRONMENTAL
ASCENT/EVACUATION FOR ONGOING CONVECTION.

AS TYPICAL THIS TIME OF NIGHT...CONVECTION IS STRUGGLING TO REACH
SHORE WEAKENING DUE TO LAND BREEZE/STABILIZING LAND CONDITIONS.
YET WITH STRONG ISENTROPIC ASCENT CONVECTION CONTINUES TO
DEVELOP/MAINTAIN AS THE BOUNDARY SLOWLY LIFTS NORTH.  AS SUCH
CONVECTION IS REACHING MARCO ISLAND VICINITY WITH UPSTREAM CELLS
TRACKING ALONG THE BOUNDARY ENE LIKELY TO REINFORCE HVY RAINFALL
POTENTIAL.  HI-RES CAMS APPEAR TO BE STRUGGLING ASSIMILATING THE
WAVE/BOUNDARY STRUCTURE IN THE EASTERN GULF AND THEREFORE ARE
DEVELOPING MORE CONVECTION FURTHER NORTH THAN EXPECTED. 
HOWEVER...RECENT ESRL HRRR V.3 IS HANDLING THE LOCATION OF THE
CONVECTION A BIT BETTER AND IS SUGGESTIVE OF 3-4" TOTALS OVER THE
NEXT FEW HOURS NEAR/JUST OFFSHORE.  OTHER GUIDANCE WHILE OFFSET
FURTHER NORTH...MAY BE OK WITH THE ORIENTATION/TRACKS OF THE
CONVECTION JUST NEED TO BE ADJUSTED SOUTHWARD SUCH AS THE 00Z
ARW/NSSL-WRF OR MAYBE MOST PREFERABLE THE 00Z NAM-CONEST...ALL
SUGGESTING 3-4" RAINS AS WELL.  AS SUCH FLOODING CONCERNS ARE
RAISED PARTICULARLY IN SW COASTAL URBAN CENTERS AND ALONG I-75. 
MORE UNCERTAINTY IS GIVEN TO HOW FAR INLAND SHOWERS/ISOLATED
EMBEDDED CONVECTIVE CORES COULD SUSTAIN.  AS SUCH AREA OF CONCERN
IS LIMITED TO SW OF LAKE OKEECHOBEE...THOUGH THIS MAY NEED TO BE
RE-ASSESSED LATER THIS MORNING.

GALLINA

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

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

LAT...LON   27088228 27038177 26868133 26628096 26088068
            25928068 25708086 25518111 25478125 25678140
            25838168 26048183 26308194 26588231 26848235