212 
FXUS62 KMLB 201055
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
555 AM EST Fri Dec 20 2019

.DISCUSSION...

...Dangerous Boating and Beach Conditions Will Continue Through This 
Weekend and Into Early Next Week...

...Gulf of Mexico Storm System Will Bring Threats For Locally Heavy 
Rainfall and Strong to Severe Storms This Weekend...

Today/tonight...High pressure over the Carolinas will remain nearly 
stationary and elongate into New England. A persistent northeast to 
east flow will be across the forecast area with a gradual moistening 
of the lower levels. A significant gradient in pcp water exists 
across the state from north to south with less than 1/2 inch values 
over north FL to about 1.75 over far south FL. The steady onshore 
flow will continue to moisten up the lower levels under a pronounced 
cap near H85. Stratocumulus will move onshore in increasing amounts 
through the day with shower coverage increasing later today and 
tonight across the coastal counties with much of the activity 
dissipating trying to move inland.

Winds will further increase across coastal counties with the diurnal 
cycle and will issue lake wind advisories for this area. The persist 
wind and ocean swell run-up will keep the threat for active rip 
currents today.

Saturday-Monday...Well-advertised cutoff H50 low will drop SE from 
OK/TX to near NOLA by early Sun Evening, then pivot eastward across 
the NE Gulf Coast and NOFL, reaching the adjacent Atlantic sometime 
between Mon evening and sunrise Tue. The system remains vertically 
stacked, with the surface low reaching offshore GA/SC at that time, 
generally remaining on the NE side of the H50 feature.

Timing differences in the forward speed of the system remain, with 
the faster GFS trending on top of the compromise CMC, which are both 
now about 12h faster than the ECM. At the surface. the 2-day trend 
has been toward a singular surface low, with little if any secondary 
development across Florida. This allows the warm front/sector to 
spread farther north over the peninsula. In turn, this would push 
the highest rainfall totals a bit farther north into NOFL Sun, while 
increasing the threat for a more organized convective band out ahead 
of the trailing occlusion due to greater instability and continued 
favorable winds/shear.

48h areal averaged QPF has dropped a tad from 2-4" to 1.5-3.0", and 
the marginal WPC excessive rainfall outlook for days 2-3 have been 
nudged just a bit farther north compared to Thu. Additionally, the 
latest SPC SWODY3 outlook for Sunday now shows a Marginal risk for 
severe storms/isolated tornadoes for the Treasure Coast and Lake 
Okeechobee region, which could be nudged farther north as well.

The overall forecast han't been changed all that much compared to 
yesterday. POPs were nudged down slightly for Sat night, remain 
highest (90 pct) on Sun, and are a little higher (60-70 pct) for 
early Mon to account for the overall slowing of the model consensus.

Tuesday-Friday...The deep layer low either near or east of the ECFL 
and SE CONUS Coast Tue morning will drift slowly eastward amd well 
away from FL by Wed, with high pressure building north of FL from 
mid to late next week. W-NW flow will shift to N-NE through Tue 
night and Wed, then slacken by Thu. Only premise for precip would be 
isolated low topped marine showers moving onshore through the period.
Below normal temps on Tue will moderate to near normal from the 
middle to end of the week. 

&&

.AVIATION...Winds will continue to veer to mainly ENE by morning. 
Mainly VFR conditions expected with ocnl stratocu moving in  off the 
Atlantic waters into coastal locations. BKN VFR cigs with only low 
coverage of showers until low levels moisten further in later 
portion of fcst period.

&&

.MARINE...Today/Tonight...XMR profiler shows a steady 25 knot wind 
through 4 kft. Buoy observations have been 22 to 25 knots with few 
gusts to 30 knots. Both GFS and ECM consistent in showing about 3-4 
mb of gradient across our marine area with no additional tightening 
over the next 36 hours. Will opt to pull back from Gale warning and 
go with a healthy SCA across all coastal waters. 

Saturday-Tuesday...Hazardous sea and surf conditions associated 
first with the strong high to the north and then the GOMEX storm 
approaching and then moving across the local waters will continue 
throughout the weekend, and likely into the early work week. Hence 
the SCA/HSA have been extended through 7 AM Mon. Winds will remain 
in the 20-25KT range for the most part, outside of a possible brief 
lull immediately behind the occluded FROPA, which results in winds 
veering to offshore. Seas building to 6-9FT near shore and as high 
as 10-13FT well offshore by Sunday. Winds and seas will be slow to 
subside late Mon-Tue as the storm system pulls east away from FL.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  72  62  72  67 /  30  30  30  90 
MCO  74  61  74  65 /  20  20  20  80 
MLB  73  66  74  70 /  30  30  30  80 
VRB  75  66  75  70 /  30  40  30  80 
LEE  72  58  74  64 /  10  20  20  90 
SFB  74  60  74  64 /  20  20  20  80 
ORL  73  61  74  65 /  20  20  20  80 
FPR  74  66  75  70 /  30  40  30  70 

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Lake Wind Advisory until 7 PM EST this evening for Coastal 
     Volusia-Indian River-Martin-Northern Brevard-Southern 
     Brevard-St. Lucie.

     High Surf Advisory until 7 AM EST Monday for Coastal Volusia-
     Indian River-Martin-Northern Brevard-Southern Brevard-St. 
     Lucie.

AM...Small Craft Advisory until 7 AM EST Monday for Flagler Beach to 
     Volusia-Brevard County Line 0-20 nm-Flagler Beach to 
     Volusia-Brevard County Line 20-60 nm-Sebastian Inlet to 
     Jupiter Inlet 0-20 nm-Sebastian Inlet to Jupiter Inlet 20-
     60 nm-Volusia-Brevard County Line to Sebastian Inlet 0-20 
     nm-Volusia-Brevard County Line to Sebastian Inlet 20-60 nm.

&&

$$

SHORT TERM/AVIATION...Blottman
LONG TERM/DSS...Cristaldi