851
FXUS62 KMLB 231920
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
220 PM EST Mon Dec 23 2024

...New KEY MESSAGES, DISCUSSION, MARINE...

.KEY MESSAGES...
Issued at 220 PM EST Mon Dec 23 2024

- Low clouds and patchy fog forecast early Tuesday morning, mainly
  along and west of the Saint Johns River Basin

- A moderate to high risk of rip currents continues this week,
  along with poor boating conditions offshore

- Low-end rain chances mid to late week with near to slightly
  above normal temperatures each day

&&

.DISCUSSION...
Issued at 220 PM EST Mon Dec 23 2024

Now-Tonight...This afternoon, a surface trough is being analyzed
along the east-central Florida coast as clouds spread westward
across the peninsula. Temperatures have climbed into the upper 60s
and low 70s with the coolest spots along the north Brevard and
Volusia coast. As advertised, a mix of sun and clouds will last
through the remainder of the afternoon as a few light showers
brush the coast from Cape Canaveral to Stuart. A low 15 percent
rain chance was added along the rest of the Treasure Coast for
this afternoon, following a largely persistence forecast, as
models have struggled to depict this activity overall.

A bit of cyclonic spin in the satellite picture is present this
afternoon, specifically about 150 nautical miles east of Cape
Canaveral. Models have been hinting the past couple of days that a
weak low pressure system could form and lift north tonight toward
the Georgia and South Carolina coast. As it does, low-level steering
flow is anticipated to veer more southerly while also weakening a
bit. In turn, the better moisture and support for coastal showers
will migrate seaward, marking an end to our rain chances tonight.

Cloud cover is forecast to build over much of the area into Tuesday
morning, but especially from Orlando/Titusville northward. Low
stratus through the early morning hours is forecast with patchy fog
explicitly mentioned, mainly from along the Saint Johns river to
points west, including the interior. Visibility could fall to one
mile or less at times (20-25 percent chance), so keep this in
mind for any early Tuesday morning travel.

Tuesday-Wednesday...Another chilly start to the day is anticipated
for Tuesday with lows ranging from the upper 40s to low 50s north of
I-4 and the mid to upper 50s elsewhere. Morning fog and low clouds
will take some time to clear with conditions improving by mid to
late morning. Temperatures will be similar to this afternoon,
ranging from the upper 60s to middle 70s (south). Much of the day
looks dry, though an isolated shower cannot be ruled out from late
afternoon into the evening along the Treasure Coast. Temperatures
inch warmer on Christmas Day with highs near to slightly above
normal. More clouds do build through the day as onshore flow returns
to the area and a weak frontal boundary becomes quasi-stationary
over central Florida. Some model guidance, though not all,
suggests that the highest chance for isolated showers will be
along this boundary. For now, this appears to be from Cape
Canaveral toward Lake Okeechobee and the Treasure Coast. Still,
only a 20 to 30 percent chance of rain seems reasonable.

Thursday-Sunday...Guidance is in better agreement through Friday
but solutions remain variable for Saturday and beyond. The overall
synoptic pattern features a weak mid level trough axis lifting
northeastward across the TN/OH Valleys on Thursday, followed by a
pressure ridge briefly building over Florida Friday and Saturday.
500mb height anomalies then show a trend toward height falls from
Sunday into Monday as a longwave trough rotates through the
central and eastern CONUS. Locally, onshore flow becomes well
established late week into the weekend with decent moisture return
(1.4-1.5" or higher at times). This forecast maintains anywhere
from a 20-30 percent chance of showers along the coast, maximized
during the daytime hours. On Saturday, the GFS tries to bring
shortwave energy across the eastern Gulf and south Florida,
enhancing rain chances there. While confidence in any one solution
regarding precipitation is not high, this one seems to be an
outlier for now. Attention then turns to a cold front approaching
Florida late in the weekend or early next week.

&&

.MARINE...
Issued at 220 PM EST Mon Dec 23 2024

With a surface trough positioned very near the coast this
afternoon, isolated to scattered showers will continue into the
early evening before pivoting increasingly seaward. Poor boating
conditions remain over the Volusia and offshore Brevard waters
with seas 5-6 ft and north winds around 15 kt (gusting around 20
kt). Northerly winds persist into Tuesday, 10-15 kt with seas 4-5
ft (occasionally 6-7 ft) well offshore. Wave heights generally
level off Wed. and Thu. as flow turns out of the east, with brief
instances up to 6 ft offshore Thursday night. Wind gusts
approaching 15-20+ kt are possible Thursday and especially Friday
afternoon. Isolated to scattered showers increase midweek on into
the weekend.

&&

.AVIATION...
(18Z TAFs)
Issued at 120 PM EST Mon Dec 23 2024

Stubborn MVFR/IFR CIGs took some time to burn off this
morning, and we might see a repeat tonight of MVFR/IFR (local LIFR)
CIGs (esp KVRB/KMLB northward) with some potential patchy fog
(interior) mixed in. NERLY winds will "back" N/NW this evening and
overnight 5-10 kts, except 5 kts or less along the Treasure Coast.
Weakening coastal trough and associated showers near coastal TAF
sites forecast to diminish into this evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  51  67  53  72 /   0   0   0  10
MCO  55  73  55  74 /   0   0   0  10
MLB  56  72  58  75 /   0  10  10  20
VRB  58  75  61  78 /  10  10  20  20
LEE  51  71  52  74 /   0   0   0  10
SFB  53  71  53  74 /   0   0   0  10
ORL  54  72  55  75 /   0   0   0  10
FPR  57  74  61  77 /  10  10  20  30

&&

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

$$

DISCUSSION...Schaper
AVIATION...Sedlock