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Area Forecast Discussion (AFD)

Issued by Melbourne, FL (MLB)

FXUS62 KMLB 192156 CCA

Area Forecast Discussion...Corrected 
National Weather Service Melbourne FL 
456 PM EST Sat Jan 19 2019


...Widespread Showers and Isolated Storms Moving In Late Tonight...
...Rapidly Deteriorating Small Craft Boating Tonight/Sunday...
...Windy/Gusty on Sunday...
...Turning Sharply Colder Sunday Night into Monday...

Current-Tonight...A strong cold front, driven by a large upper 
trough, will move into the FL Panhandle by early this evening, then 
sweep southeastward across ECFL late overnight into early Sun 
morning (daylight). Out ahead of this front will be a fast-moving 
band (40-50 mph out of the SW or W) of widespread showers and 
isolated lightning storms. PWAT values are forecast to increase in 
upwards of 1.60 inches ahead of the front. Should see a lull in our 
surface winds briefly this evening, but the pressure gradient 
tightens later this evening and overnight as the strong front 
approaches, especially after midnight. Outside of convection some 
locations may see wind gusts in excess of 20 to 25 mph. Wind fields 
at around 925 mb are stout with speeds approaching 40 kts. Combined 
with convection moving into the area some of these winds may 
potentially mix down to the surface in terms of wind gusts. Aside 
from wind speeds approaching 50 mph in some storms, other threats 
include torrential downpours, and occasional to frequent lightning. 
The tornado threat is low. 

While some cells could make it into the I-4 corridor late in the 
evening, the preferred timing from short-term models is after 
midnight spreading south and east of I-4 after 4AM, the Treasure 
Coast near or just after sunrise. All of the precip should be clear 
of land by mid to late morning Sun. Rainfall amounts look higher 
across the north, up to one half inch Orlando northward with lower 
amounts south of Orlando. 

Sun...The front will be through much of the area shortly after 
sunrise, then Okeechobee/Treasure Coast near mid morning. We will 
likely need a Lake Wind Advisory areawide for sustained winds 15-25 
mph and frequently gusty. Early morning clouds will gradually 
diminish through late morning and early afternoon as dry air 
infiltrates the area. Highs will be cooler and mainly in the L-M60s 
near/north of I-4 and U60s to near 70 degrees in a few spots along 
the Space/Treasure coasts. Temperatures will fall late in the day 
and toward sunset as cold air advection pours into the area. 

Sunday evening-Tuesday...Very chilly temperatures are expected 
Sunday evening into Monday morning as a much cooler and drier 
airmass will continue to spill into the region behind the cold 
front.  Strong cold air advection and clearing skies will allow 
temperatures to rapidly drop through the evening and overnight. Most 
places will already be in the mid-upper 40s by late Sunday evening 
with overnight lows expected to be in the mid to upper 30s 
(immediate Treasure Coast low 40s). With winds expected to remain 
between 5 and 10 mph, it will feel even colder with wind chill 
values dropping into the low-mid 30s overnight Sunday into early 
Monday. This may prompt a Wind Chill Advisory for portions of east 
central Florida.

Plenty of sunshine for Monday thanks to dry air mass, but it will 
still be pretty chilly by Florida standards. Cold air advection 
remains in place keeping high temperatures in the mid to upper 50s 
northern areas with some lower 60s to the south. Northerly winds 
around 10 mph interior/10-15 mph coast will make it feel pretty 
"crisp" out.  

Monday night into Tuesday, temperatures will follow a warming trend 
as winds veer onshore from high pressure building in across the Mid-
Atlantic.  Overnight lows Mon. night/Tuesday morning will be in the 
upper 40s/low 50s along the coast and mid-upper 40s interior. 
Pressure gradient is forecast to tighten on Tuesday resulting in 
some breezy conditions, especially along the coast.  This will bring 
in marine stratocu off the Atlantic and also result in an uptick in 
shower activity over the coastal waters.  Could see a shower or two 
make it onshore but have kept shower chances along the coast below 
mentionable levels due to air mass still being quite dry. High temps 
will be in the upper 60s far north and low 70s elsewhere. 

Extended AFD.../237 PM EST SAT JAN 19 2019/

Wed-Sat...On Wed surface high pressure will push eastward from the 
offshore mid Atlantic waters with breezy southeast flow around the 
Atlantic ridge. Enough low level moisture should support low shower 
chance with some isolated Atlc showers moving onshore and NNW across 
east central FL. Deep moisture will increase Wed night into Thu 
morning ahead of a longwave trough approaching the ern CONUS. This 
will bring numerous showers and isolated storms to the area late Wed 
night into Thu. A few strong storms will be possible Thu. The 
surface front will move southeast of the area Thu night into early 
Friday with lingering shower chances across southern sections into 
early Fri before drier air moves into the area Friday night into 
Sat. Highs into the mid to upper 70s Wed-Thu will cool behind the 
front to the 60s on Friday into Sat. Lows in the 60s Wed night will 
drop into the 50s Thu night and 40s across much of the area for 
Friday night. 


.AVIATION...SSW to SSE winds will see a brief lull in speeds 
during the early evening before ramping back up ahead of an 
approaching strong cold front while veering to SSW/SW. Surface winds 
will gradually become gusty after midnight. Have kept inherited non 
convective low level wind shear at several of the northern terminals 
(aft 06Z). CIGs will gradually lower aft 03Z with TEMPO MVFR/IFR 
restrictions as widespread SHRA and isold TSRA push rapidly eastward 
from the Gulf of Mexico. 

On Sun, convection should rapidly push off of the east coast. In its 
wake a very windy day as W/WNW winds increase in upwards of 20kts 
with gusts 25-30kts. Lower CIGs early in the period will gradually 
improve through the morning and early afternoon.


.MARINE...Remainder of aftn-Sun...Southerly winds will be on the 
increase from late this afternoon through overnight ahead of an 
approaching strong cold front. Winds will veer to SWRLY tonight and 
WRLY on Sun behind the weather system. Wind speeds will increase to 
20-25 kts near shore with frequent higher gusts and 25-30 kts 
offshore with frequent gusts to gale force. A Small Craft Advisory 
(SCA) goes into effect at 21Z/4PM, but then is dropped in favor of a 
Gale Warning at 09Z/4AM. Near shore waters will see an SCA for Winds 
begin at 03Z/10PM, but will start out 4pm coastal waters forecast 
issuance with Cautionary Statements near shore for the increasing 
winds. Seas 1-2 ft near shore and 2-3 ft offshore will build 
overnight to 3-5 near shore and 5-7 ft offshore. Seas continue to 
build on Sun to 4-6 ft near shore (away from the coast) and 6-9 ft 

A fast-moving band of showers with isolated thunder will move off of 
the Volusia coast after midnight through near daybreak, the Brevard 
coast late in the night through just after sunrise and the Treasure 
Coast near sunrise through mid morning. Wind gusts in excess of 
35kts associated with the convection will be possible.  

Monday-Tuesday...Poor to hazardous boating conditions continue into 
Monday morning.  Conditions are then expected to gradually improve 
somewhat with northerly winds diminishing to around 15 kt over the 
coastal waters.  Seas will subside to 3-4 ft nearshore (expect 5-6 
ft near the Gulf Stream) and 3-5 ft offshore (5-6 ft near the Gulf 

Winds veer to easterly on Tuesday as high pressure builds in to our 
north. Pressure gradient is forecast to tighten resulting in winds 
increasing to 15-20 kt south of the Brevard/Volusia line.  Speeds 
are expected to be around 15 kt north.  Seas will build back to 4-5 
ft but could approach 6 ft near the Gulf Stream Tuesday afternoon 
and evening.

Wed-Thu...SE winds near 20 knots Wed will veer to the south Wed 
night and SW Thu and increase to 20-25 knots offshore. Seas 4-6 ft 
nearshore and 6-7 ft offshore Wed will continue 4-6 ft nearshore 
into Thu but build to 7 to 8 ft across the offshore waters as the 
pressure gradient tightens ahead of the next advancing front. High 
rain chances are expected late Wed night into Thu with isolated 
storms bringing the chance for convective gusts above 35 knots.


.FIRE WEATHER...Late tonight/Sun...A strong cold front will bring a 
good chance for rain overnight with isolated thunder into early 
Sunday with blustery conditions and colder temperatures behind the 
front. Southwest winds will become gusty after midnight, then post-
frontal W/WNW winds will increase to 20-25 mph with frequent higher 
gusts during the day increasing fire sensitivity. Drier air will 
take some time to filter southward across the peninsula with 
forecasted min RHs in the 40s in the afternoon.


DAB  57  63  37  55 /  80  20   0   0 
MCO  60  64  39  59 /  80  30   0   0 
MLB  61  69  40  61 /  60  50   0   0 
VRB  63  70  41  62 /  50  60   0   0 
LEE  56  61  36  58 /  90  20   0   0 
SFB  58  64  37  58 /  80  20   0   0 
ORL  60  65  39  58 /  80  30   0   0 
FPR  62  72  41  63 /  40  60   0   0 


AM...Small Craft Advisory for winds from 10 PM this evening to 10 PM 
     EST Sunday for Flagler Beach to Volusia-Brevard County Line 
     0-20 nm-Sebastian Inlet to Jupiter Inlet 0-20 nm-Volusia-
     Brevard County Line to Sebastian Inlet 0-20 nm.

     Small Craft Advisory until 4 AM EST Sunday for Flagler Beach to 
     Volusia-Brevard County Line 20-60 nm-Sebastian Inlet to 
     Jupiter Inlet 20-60 nm-Volusia-Brevard County Line to 
     Sebastian Inlet 20-60 nm.

     Gale Warning from 4 AM to 10 PM EST Sunday for Flagler Beach to 
     Volusia-Brevard County Line 20-60 nm-Sebastian Inlet to 
     Jupiter Inlet 20-60 nm-Volusia-Brevard County Line to 
     Sebastian Inlet 20-60 nm.



MID TERM...Combs