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Area Forecast Discussion (AFD)

Issued by Melbourne, FL (MLB)

                            
556 
FXUS62 KMLB 260756
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
356 AM EDT Sat May 26 2018

.DISCUSSION...
...Flood Watch in effect for East Central Florida over the Holiday 
Weekend...
...Locally Heavy Rainfall is Expected...

Today and Tonight...Recent short range guidance has backtracked 
on coverage of pcpn over northern areas today. This appears to be 
due to lack of instability as well as more mid level drying than 
anticipated to start out. Showers should develop primarily over 
the southern half of the forecast area south of Orlando to 
Sebastian Inlet during the afternoon with an increase in coverage 
from the south across all sections by late afternoon as deeper 
moisture encompasses the whole region by dusk. Isolated lightning 
storms will be possible mainly south of Orlando and the Space 
Coast with highest rain amounts of around a quarter of an inch to 
a tenth of an inch. Rain chances will increase overnight as rich 
moisture and convergent flow ascd with the increasing wind field 
indirectly ascd with TC Alberto begins to enter the picture. An 
evolving threat of a few rotating storms will begin to enter the 
region from the south toward daybreak Sunday. Will thus keep a 
numerous showers mentioned overnight and embedded storms with lows
remaining in the 70s. 

Sun-Mon...Latest NHC guidance has the center of Alberto making its 
closest approach to FL Sunday morning, roughly around 250 miles to 
the W/SW of the SW FL coast. Alberto is then expected to move N/NW 
across the central/eastern Gulf of Mexico through Monday, making 
landfall along the northern Gulf coast early Tuesday morning. Rain 
chances ramp up considerably into Sunday (up to 80%) and remain high 
Monday (70-80%) as deep southerly flow to the east of Alberto 
transport a very moist tropical airmass with PW values of 2+ inches 
northward across the area. 

Heavy rainfall and localized flooding remain the main concerns from 
this system, with the potential for training bands of showers and 
storms moving northward across the area. Additional rainfall totals 
of 2-3 inches are generally expected through Sun-Mon across much of 
the area, with locally higher totals possible. A Flood Watch remains 
in effect for all of east central Florida during this timeframe. An 
isolated tornado threat will also exist across the region, mainly 
into Sunday, when low level helicity values are maximized to the 
east of Alberto. While wind threat continues to remain low for the 
area with Alberto's forecast track, breezy S/SE winds will still be 
expected into Sunday, with stronger showers and storms having the 
potential to produce strong wind gusts. 

Cloudy to mostly cloudy skies will persist through the holiday 
weekend, keeping highs limited to the low 80s on Sunday and mid 80s 
on Memorial Day. Overnight lows will remain above normal with values 
in the low to mid 70s.  

Tue-Fri...Even as Alberto weakens after landfall along the northern 
Gulf coast, a moist plume of 2+ inch PW values will persist in a 
deep S/SW flow over the area. This will continue a wet pattern 
through at least Wednesday, with likely rain chances (60-70%) 
forecast across much of the region. Showers and storms will likely 
transition to becoming more diurnally driven, with greatest coverage 
in the afternoon each day. Into late week, models indicating a 
slight decrease in rain chances as deeper moisture shifts south and 
east. However, scattered shower and thunderstorm coverage still 
possible each afternoon. Highs will range from the mid-upper 80s, 
with low 90s possible across portions of the area on Friday. 

&&

.AVIATION...Expect VFR conds to start this morning with isold 
shra developing FM 26/13Z-26/16z. Aft 26/17Z lcl MVFR conds in 
SHRA/TS. Obstructions to SKY and VIS wl be ascd with showers 
increasing in coverage and LCL TSRA FM 26/18Z-27/08Z. 

&&

.MARINE...SE flow 10 to 15 kts will increase steadily to 15 to 20
knots this afternoon enhanced somewhat by an onshore coastal 
breeze developing. Seas 3 to 5 ft will increase in the developing
onshore wind gradient into tonight and an advisory will go into 
effect for a portion of the nearshore and offshore waters at 4 PM 
mainly due to sustained winds near 20 knots. 

Sun...Hazardous boating conditions expected over the waters Sunday 
into Sunday night, as S/SE winds increase up to 20-25 knots well to 
the east of Alberto over the central/eastern Gulf. These winds will 
build seas up to 7 feet, mainly offshore, with seas nearshore up to 
5 to 6 feet. Have issued an SCA for the entire coastal waters for 
Sunday, which will continue for most of the adjacent Atlantic into 
Sunday night. 

Mon-Wed...Poor boating conditions will likely continue into Memorial 
Day as model guidance only shows a slow decrease in winds and seas 
into early next week. S/SE winds are still forecast up to 15-20 
knots Monday with seas up to 6 feet offshore.

Winds and seas will then continue to gradually improve through mid 
week, with southerly winds decreasing to 10-15 knots and seas 
falling to 5 feet or less.  

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  86  74  82  74 /  20  60  80  50 
MCO  85  72  82  73 /  40  60  80  50 
MLB  82  75  83  75 /  50  70  80  60 
VRB  82  75  84  75 /  60  70  80  60 
LEE  87  73  82  74 /  40  60  80  50 
SFB  86  72  82  73 /  30  60  80  50 
ORL  84  71  82  74 /  40  60  80  50 
FPR  82  74  84  75 /  60  70  80  60 

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch from 2 PM EDT this afternoon through Monday evening 
     for Coastal Volusia County-Indian River-Inland Volusia 
     County-Martin-Northern Brevard County-Northern Lake County-
     Okeechobee-Orange-Osceola-Seminole-Southern Brevard County-
     Southern Lake County-St. Lucie.

AM...Small Craft Advisory from 8 AM to 10 PM EDT Sunday for Flagler 
     Beach to Volusia-Brevard County Line 0-20 nm.

     Small Craft Advisory from 8 AM Sunday to 8 AM EDT Monday for 
     Flagler Beach to Volusia-Brevard County Line 20-60 nm-
     Volusia-Brevard County Line to Sebastian Inlet 0-20 nm.

     Small Craft Advisory from 4 PM this afternoon to 8 AM EDT Monday 
     for Sebastian Inlet to Jupiter Inlet 0-20 nm-Sebastian 
     Inlet to Jupiter Inlet 20-60 nm-Volusia-Brevard County Line 
     to Sebastian Inlet 20-60 nm.

&&

$$

SHORT TERM...Pendergrast
LONG TERM....Weitlich