Area Forecast Discussion
Issued by NWS Melbourne, FL

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FXUS62 KMLB 030922
AFDMLB

Area Forecast Discussion...Corrected
National Weather Service Melbourne FL
422 AM EST Sun Dec 3 2023

...New DISCUSSION, MARINE, AVIATION...

.DISCUSSION...

Current...Increasing clouds across the north early this morning
from a combination of high clouds spilling over an upper level
ridge centered south of FL, and low stratus rapidly spreading NE
from the western peninsula in freshening SW flow just above the
surface. In addition, some mist/fog has started to form in this
area, and traffic cams show this becoming dense in a few spots
around Lake Apopka, Green Swamp and the KISM attractions area.
Low clouds will become widespread across the northern half CWA
through sunrise, with some increase in fog expected. Magnitude
(15kt) of SW flow just off the deck normally favors widespread
stratus over dense/widespread fog but will continue to monitor.

Today-tonight...The mid level ridge extending northward from the
Greater Antilles into SOFL/Straits shifts east/flattens through
tonight as an elongated vortlobe sags south into NOFL. At the
surface, after the fog/stratus erodes later this morning, light-
moderate S-SW winds on the western flank of an eroding Atlantic
ridge veer WSW/freshen ahead of an approaching cold front. The
front will sag across NOFL this afternoon, then become oriented
parallel to the low level wind flow, which causes it to slow and
become more diffuse as it oozes into ECFL overnight.

While moisture increases (GFS PWATs 1.6"-1.7"/ECM 1-2 tenths lower)
the overall pattern across FL isn`t overly favorable for precip to
develop, given the lack of significant source for lift, outside of
some weak upper divergence. Went with diurnal POPs of 20% from Lake
Kissimmee-Melbourne to around I-4, and 30 from I-4 northward. H50
temps fall to -8C/-9C across the north/central as surface temps
climb into the L-M80s. Resultant instability (SBCAPEs 1000-1500
JKG-1) supports potential for a few lightning strikes during the
mid-late afternoon. Mostly cloudy overnight with isolated evening
showers possible. Mins in the M-U60s.

Monday-Tuesday...A cold front is forecast to move southward across
the peninsula Monday into Monday night, with isolated shower
development forecast along and ahead of the front. Have kept PoPs
around 20 percent on Monday, and took out mention of thunder except
for across the local Atlantic waters. The global models remain in
fairly good agreement that the boundary will push south of east
central Florida and stall and eventually diminish across south
Florida and the Keys, with the Euro showing a faster decay of the
boundary than the GFS. An area of surface high pressure is then
forecast to shift eastward from the central US and gradually
strengthen across the southeastern US on Tuesday behind the front,
with northerly winds locally helping the drier and cooler airmass
filter in across east central Florida. This will be most noticeable
on Tuesday, with lower relative humidities and rain chances less
than 10 percent.

Out ahead of the front on Monday, the warm, moist airmass will keep
temperatures in the upper 70s to mid 80s. As the front pushes
through, cooler air will follow behind, with overnight lows on
Monday dropping into the low to mid 50s. Afternoon highs on Tuesday
will also fall closer to climatological normal for this time of
year, with temperatures in the low to mid 70s across east central
Florida. Overnight lows on Tuesday in the upper 40s to low 50s.

Wednesday-Saturday...Dry conditions are forecast across east central
Florida through the remainder of the period. A mid-level trough will
sweep across the southeastern US on Wednesday, pushing a reinforcing
frontal boundary across the peninsula at the surface, with even
drier and cooler air forecast to push in behind the front. As a
result, clearing skies are forecast across the area Wednesday
through Thursday. As the surface high shifts eastward towards the
Atlantic, onshore flow will return Thursday into Friday, leading to
some increasing moisture across the area and therefore increasing
cloud coverage.

Coolest temperatures are forecast on Wednesday as a result of the
reinforcing boundary, with afternoon highs in the low 60s to low 70s
and overnight lows in the low 40s to mid 50s. Temperatures will then
gradually warm through the remainder of the week into the weekend,
with afternoon highs in the mid 60s to mid 70s on Thursday and in
the low 70s to low 80s Friday and Saturday. Overnight lows in the
mid 40s to upper 50s on Thursday and in the low 50s to mid 60s
Friday and Saturday nights.


&&

.MARINE...
Issued at 408 AM EST Sun Dec 3 2023

Today-tonight...SW winds 10kt or a little less near shore and
10-15kt well offshore freshen by a few kts offshore the Volusia
/Brevard coasts as they veer to SW-W this afternoon, This will
preclude any increase in seas, which will remain 2-3ft nearshore
and 3-4ft well offshore. Winds remain W-WSW overnight with speeds
slackening a bit, allowing seas to fall back to 2-3ft.

Monday-Thursday...A cold front will move across the local Atlantic
waters Monday into Monday night, with isolated to scattered showers
and a stray thunderstorm or two forecast. Behind the front,
conditions dry out as an area of high pressure builds across the
southeastern US. West winds on Monday will veer to out of the
northwest on Tuesday, generally between 10 to 15 knots. On
Wednesday, a reinforcing frontal boundary will push southward across
the Florida peninsula and local Atlantic waters, resulting in the
northwesterly winds increasing to 15 to 25 knots across the local
Atlantic waters. Winds will veer to out of the northeast on Thursday
and decrease back to 10 to 15 knots. Seas 2 to 4 feet on Monday and
Tuesday, increasing to 4 to 8 feet on Wednesday due to the winds,
and then decreasing slightly to 3 to 7 feet on Thursday.

&&

.AVIATION...
(06Z TAFS)
Issued at 408 AM EST Sun Dec 3 2023

IFR-LIFR stratus CIGs OVC002-007 have become widespread along/west
of ISM-MCO-SFB-DED. Thus far, VSBY reductions have been limited to
LEE, while having become widespread well SW of ISM. There should be
some NE spread of low CIGs toward or across DAB-TIX through 12Z,
with potential for IFR to LIFR VSBYs to reach ISM-MCO-ORL. Any fog
should burn off by 13Z, with IFR CIGs lingering through 14-15Z.

&&

.HYDROLOGY...
Issued at 408 AM EST Sun Dec 3 2023

The Saint Johns River at Astor is forecast to continue a very
slow decline this week. The river is forecast to remain within
Minor Flood Stage through mid week, but could fall into Action
Stage later in the week. Near Geneva, Above Lake Harney the
river is expected to fall below Action Stage later today.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  82  66  80  51 /  30  20  10   0
MCO  84  69  80  55 /  30  20  20   0
MLB  84  67  83  56 /  20  10  20   0
VRB  85  67  83  56 /  10  10  20   0
LEE  82  67  78  53 /  30  20  10   0
SFB  84  67  80  53 /  30  20  10   0
ORL  85  69  80  56 /  30  20  10   0
FPR  85  67  83  56 /  10  10  20   0

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&

$$

SHORT TERM...Cristaldi
LONG TERM....Tollefsen
AVIATION...Cristaldi


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