Area Forecast Discussion
Issued by NWS Melbourne, FL

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FXUS62 KMLB 210220
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
920 PM EST Mon Nov 20 2017

.DISCUSSION...

Relatively quiet WX pattern overnight as hi pres over the ern
seaboard pushes into the W Atlc and maintains a steady easterly flow
acrs central FL. Frontal boundary extending from the srn GOMex acrs
the FL Straits will dissipate, though its remnant H100-H70 moisture
band/H85-H70 theta-e ridge will begin to drift back to the north as
mid lvl winds veer to the SE.

Evng KXMR/KTBW RAOBs continue to show a very dry/stable airmass over
central FL with PWat values arnd 0.75", avg H85-H50 dewpoint
depressions btwn 20-30C over the Treasure Coast/Lake-O region, and a
sharp subsidence inversion in the H85-H70 lyr. PWat increases to
arnd 1.50" at KMFL/KEYW, much of which is trapped blo the same mid
lvl subsidence inversion, albeit in a much weaker state. Latest
radar images from KMFL do show banding precip moving onshore, but
limited to points south of Broward Co and showing no sign of any
northward drift.

While H100-H70 moisture is expected to increase as hi pres builds
over the W Atlc, the dry/stable air over central FL will require
significant modification before it can support any precip. Indeed,
the HRRR and lcl WRF models are quite bearish on precip dvlpg over
the Treasure Coast overnight, and even then, more in the predawn hrs
than overnight.  As such, will cull PoPs back to 20pct aft 09Z with
the evng update. Onshore flow will keep overnight min temps abv
avg...L/M60s inland and M/U60s along the coast.

&&

.AVIATION...Thru 22/00Z.
Sfc Winds: Thru 21/06Z...Coastal sites E/NE 8-12KTS...interior sites
4-8KTS. Btwn 21/06Z-21/12Z...E/NE 4-8KTS. Btwn 21/13Z-21/16Z...bcmg
E/SE 7-11KTS. Btwn 21/21Z-21/24Z...N of KMLB-KISM bcmg E/NE 5-
9KTS...S of KMLB-KISM bcmg SE 4-8KTS.

Vsbys/WX/Cigs...Thru 21/13Z prevailing VFR SCT-BKN040-050...aft
21/06Z bcmg multilayered BKN-OVC btwn FL080-120. Btwn 21/13Z-
21/16Z...S of KMLB-KISM areas MVFR cigs/vsbys in -RA/RA/BR...N of
KMLB lcl MVFR cigs/vsbys in -RA/BR. Aft 21/16Z...prevailing cigs
btwn FL060-080...areas MVFR cigs/vsbys and lcl IFR cigs/vsbys in +RA
all sites...slgt chc TSRA.

&&

.MARINE...
The center of a large hi pres ridge blanketing the ern CONUS will
drift off the Carolina Coast overnight, maintaining a gentle to
moderate easterly breeze while doing so...ocnl G20KTs. Latest buoy
obs are indicating 4-6FT seas in the shelf waters, 5-7FT in the Gulf
Stream...dominant pds btwn 6-7sec resulting in rough conditions with
steep wave faces. While winds are expected to diminish slightly
overnight as the ridge pushes into W Atlc, overall conditions will
remain poor enough to continue latest advisory/cautionary statements
overnight.

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory until 4 PM EST Tuesday for Sebastian Inlet
     to Jupiter Inlet 20-60 nm-Volusia-Brevard County Line to
     Sebastian Inlet 20-60 nm.

     Small Craft Advisory until 10 AM EST Tuesday for Sebastian Inlet
     to Jupiter Inlet 0-20 nm.

&&

$$

Short Term/Aviation...Bragaw
Impact Wx/Radar.......Sedlock



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