Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus62 kmlb 170715 

Area forecast discussion
National Weather Service Melbourne Florida
215 am EST Fri Nov 17 2017


Current...light shower activity associated with a southward moving
convergent boundary diminishing early this morning across Martin
County and the adjacent near shore coastal waters. This as deep
layer drying forcing deepest moisture further southward across the
Florida Peninsula. Fair conditions elsewhere with light/variable
winds and temperatures in the 50s to l60s areawide.

Today-tonight...northwest flow aloft expected over the region for
the next 24 hours with no hint at any favorable positive vorticity
advection. Precipitable water values forecast to fall below 1 inch
areawide through the day and tonight. Conditions should remain
mainly dry with precip chances less than 10 percent. At the surface
high pressure over the eastern Seaboard will slowly weaken and move
off of the mid Atlc coast overnight. Light morning northwest winds
will veer to northeast during the day increasing up to around 10 mph
over the interior and 10-15 mph at times near the space/Treasure
coasts, though the pressure gradient will remain weaken than
previous days. Winds will become light to near calm again later this
evening and overnight. Skies should be msunny for much of ecfl early
today but will need to watch for the approach of some stratocumulus
clouds toward the East Coast with some occasional broken periods of
skies possible.

A pleasant day in store with highs generally in the M-u70s with some
l70s probable along the immediate Volusia coast. Lows typically in
the 50s over the interior and Volusia coast with some lower 60
degree readings likely near the space/Treasure coasts and barrier
islands. Will not include any patchy fog mention for late overnight
into early Sat morning, along/northwest of I-4, and defer to the day

Saturday-Monday night...a weak ridge of high pressure will briefly
build eastward from the Gulf of Mexico across Florida through
Saturday night. A broad short wave trough moving through the eastern
Continental U.S. Will erode and collapse the ridge Sunday, followed by another
fast moving short wave trough moving across the deep south and
reaching the Gulf Coast by Monday night. At the surface, a narrow
ridge will drop across Florida through Saturday night. The ridge
will give way to a cool front, which will move through east central
Florida, reaching south of Lake Okeechobee by early Sunday evening.
High pressure will build rapidly eastward, north of Florida behind
the front. Conditions will remain dry/comfortable ahead of the

The fast moving front will increase moisture briefly ahead of the
front. Then dry and cooler Monday, with rapid return of maritime air
in onshore flow with showers developing along/offshore the Treasure
Coast Monday night.

Tuesday-Friday...guidance indicates a surface ridge to the north
will rapidly weakening as an inverted trough forms off the Florida
East Coast late Tuesday. This is in response to the trailing short
wave trough Monday night and lingering off the southeast Seaboard through
Wednesday. Upstream, a large weak area of lower pressure is forecast
to develop over the west-central Gulf of Mexico, then drift slowly
east toward the east through late week. Moisture will spread north,
with highest rain chances 40-50 Tuesday. Max temps generally in the
upper 70s with mins in the middle-upper 60s.


Aviation...mainly VFR thru the period as mainly drier conditions
expected areawide. Early morning light nwrly flow should veer to
nerly, but pgrad will be weaker with overall lighter winds than
previous days. Will need to watch for some encroaching marine clouds
near the East Coast later today with cigs 040-060 possible, at
times. MOS guidance hinting at some patchy fog potential near/north
of I-4 late overnight into early Sat morning, but will wait for
further model consistency/confidence before considering to include
in any taf sites here.

&& pressure riding along the eastern
Seaboard will continue to slowly weaken with the center pushing off
of the mid Atlc states overnight. Will start the forecast period
with cautionary statements for the Gulf Stream as seas remain
forecast to build in upwards of 6 ft here. Morning northwest/north winds are
forecast to veer toward the NE with speeds approaching 15 kts over
the open Atlc, possibly up to 17 kts over the Gulf Stream south of
Sebastian Inlet. The trend is for the gradient to weaken into the
afternoon and tonight, as wind speeds diminish to 6-12 kts with the
directional component continuing to veer tonight to E/ESE. The
cautionary statements may be able to be dropped tonight as seas
continue to subside areawide to 4-5 ft by daybreak Sat morning.

Saturday-Tuesday...winds/seas will subside through early Sunday as
the high pressure ridge moves over the local Atlantic. Light-
moderate offshore flow expected ahead of sunday's cold fropa,
followed by a strong NE surge spreading south Sunday night, veering
to east on Monday, weakening Tuesday with local inverted trough

Seas will decrease back to 3-4ft through Sunday, then building back
up to 4-6ft Sunday/5-7ft Monday, then back to about 3-5ft by


Preliminary point temps/pops...
dab 74 57 81 61 / 0 0 0 10
mco 78 58 83 60 / 0 0 0 10
mlb 77 60 81 60 / 0 0 0 0
vrb 78 59 81 59 / 0 0 0 0
Lee 78 57 81 62 / 0 0 0 10
sfb 77 57 82 61 / 0 0 0 10
orl 78 60 81 62 / 0 0 0 10
fpr 78 58 80 58 / 0 0 0 0


Mlb watches/warnings/advisories...

National Weather Service Glossary of Abbreviations