445
FXUS62 KMLB 252341
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
641 PM EST Wed Dec 25 2024

...New AVIATION...

.KEY MESSAGES...
Issued at 123 PM EST Wed Dec 25 2024

- Temperatures turn warmer late this week. Long stretches of dry
  weather are anticipated, but low shower chances remain in the
  forecast.

- A High Risk for dangerous rip currents continues at Atlantic
  beaches tonight. Poor to hazardous Gulf Stream boating
  conditions return beginning Friday.

- Our next cold front arrives Sunday with a 50% chance of showers
  and a few lightning storms. Behind the weakening front, drier
  weather returns but no significant cold temperatures are
  forecast through New Year`s Day.

&&

.PREVIOUS DISCUSSION...
Issued at 123 PM EST Wed Dec 25 2024

              ----------Synoptic Overview----------

Weak mid-level ridging remains centered near Florida this Christmas
holiday, ahead of a weak shortwave trough over Louisiana. Diffluence
in the right-rear quadrant of a 70 KT jet streak at 300 hPa is
producing meager synoptic-scale lift over the state. At the surface,
high pressure continues to wedge down the Eastern Seaboard,
generally in control of our local weather. An increasing onshore
component to our winds will gradually introduce additional warmth
and moisture to the local area as we approach the weekend.

The overall pattern across the U.S. through this weekend will be
strongly influenced by an eastward extension of the Pacific jet into
the northwest United States. On the eastern flank of this jet, a
modest trough is forecast by ensemble guidance to work eastward, its
attendant cold front likely to reach Florida sometime late on
Sunday. With additional Pacific energy on its heels, this trough
should fill quickly by Monday, leaving quasi-zonal flow over much of
the nation as we say goodbye to 2024. Therefore, over the next
week or so, no substantial local temperature fluctuations are
forecast.

After that time, the large-scale pattern evolution is worth
monitoring closely. Over the next ten days, guidance slowly moves a
large area of above-normal heights toward NE Canada and Greenland.
This can be a precursor signal for a budding -NAO; ultimately, a
preponderance of the guidance does develop a -NAO in early
January. Early in the new year, long-range ensemble guidance
suggests eventual long-wave trough development over the eastern
United States and a retraction of the Pacific jet. Significant
timing differences exist, but the pattern is beginning to look
favorable for a period of much colder weather over Central
Florida sometime during the first half of January. To that end,
the CPC 8-14 day and experimental 3-4 week outlooks favor below-
normal temperatures.

             -------Sensible Weather & Impacts-------

Now-Saturday...

Guidance has tended to overestimate rainfall potential over the last
few days. Downward-trending rain chances have been a common theme
that once again peppered across today`s forecast updates. A few
sprinkles remain with us tonight (mainly virga, or rain that
evaporates before reaching the ground). Somewhat drier air and more
sunshine are forecast tomorrow, limiting shower coverage to the
Treasure Coast (20%). Statistical guidance slightly bumps us to 20-
30% shower chances Fri/Sat, favoring the coast. Residents and
visitors should have an umbrella ready to go but also anticipate
ample stretches of dry time.

With that in mind, hopefully, folks can get out and take advantage
of the mild weather on the way in these waning days of 2024.
Afternoons should range from the mid 70s to near 80F, warmest over
the interior. Some patchy fog is possible where skies are clear
early in the morning, which isn`t unusual for the time of year.

Sunday...

Warm and somewhat breezy conditions are forecast. All guidance
points toward a (weakening) cold frontal passage on Sunday. A surge
of moisture and lift from the boundary should spark 40-50% coverage
of showers and isolated lightning storms as we wrap up the weekend.
25/00Z EPS-EFI analysis shows no significant excessive rainfall
signal and only a modest signal for CAPE/bulk shear overlap,
primarily focused over the Panhandle and N Fla. Proximity soundings
are not impressive, revealing a tall/skinny CAPE profile and 0-6 KM
shear <= 30 KT. Brief gusty winds would be the primary concern,
particularly if any storms can reach into the drier mid-level
environment. Overall, the threat of severe weather looks fairly low
at this time.

Next Week...

In short, we anticipate little/no significant impactful weather
from Monday through at least New Year`s Day. Behind Sunday`s
front, appreciable cooling appears to miss Florida. Drier air
should quickly be entrained on the south side of the strong zonal
jet extending over the mid-latitudes. Statistical guidance
lingers a low shower chance on Monday, which we will leave for
now. It is far more likely that dry weather will be commonplace
from Monday through much of next week. Additional jet stream
energy, currently off the coast of Japan, is forecast to send a
moisture-starved cold front toward the state by mid-week. The EPS
remains stronger with this front than the GEFS. So, while
temperatures should remain near to above normal through mid-week,
there is at least a low risk of colder temperatures late next
week. Regardless, subsequent and potentially significant cold
fronts are a concern in early/mid-January due to reasons
mentioned in the synoptic overview.

&&

.MARINE...
Issued at 123 PM EST Wed Dec 25 2024

High pressure resides northeast of the waters for the remainder of
the week. Poor boating conditions in the Gulf Stream will improve
through tomorrow before worsening again on Friday as a surge of
moderate to fresh easterly winds develops over the local Atlantic.
These poor offshore conditions are forecast to continue through the
weekend as winds veer southeasterly ahead of an approaching cold
front. Nearer to shore, seas 3-4 FT through tomorrow, building to 3-
5 FT from Friday through Sunday.  Intracoastal and inshore boaters
should expect a moderate chop each day. A low chance for showers
exists tomorrow, increasing in coverage to 30-60% (highest offshore)
on Friday. There will be a low risk of lightning storms and gusty
winds with the cold front late Sunday.

&&

.AVIATION...
(00Z TAFs)
Issued at 641 PM EST Wed Dec 25 2024

Satellite imagery shows broken to overcast skies at all east
central Florida terminals this evening. Lower stratus builds
overnight across the north. Have included prevailing MVFR CIGs at
LEE/SFB with a MVFR TEMPO at DAB. VFR forecast at all other
terminals tonight. North winds diminish to around 5 kts into the
evening and overnight. East to northeast winds increase to 7-9 kts
by late morning and into tomorrow afternoon.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  56  73  61  76 /  10  10  20  20
MCO  58  78  62  77 /  10  10   0  20
MLB  63  75  66  76 /  10  10  20  30
VRB  62  76  66  78 /  20  20  20  30
LEE  56  74  60  78 /  10   0   0  10
SFB  57  76  61  78 /  10  10  10  20
ORL  58  77  62  78 /  10  10  10  20
FPR  61  77  66  77 /  20  20  20  30

&&

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

$$

DISCUSSION...Heil
AVIATION...Law