Alafaya, Florida 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

973
FXUS62 KMLB 180801
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
301 AM EST Sat Jan 18 2025

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

.KEY MESSAGES...
Issued at 301 AM EST Sat Jan 18 2025

- Much warmer and breezy this weekend. A cold front arrives on
  Sunday, leading to a high chance for rain and a few storms.
  There is a Marginal (5%) risk for strong, gusty winds on Sunday.

- Florida will occasionally feel the effects of an Arctic outbreak
  across the U.S. Well-below-normal temperatures are particularly
  likely on Monday and Wednesday, when wind chills may dip as low
  as the upper 20s to low 30s northwest of Orlando.

- Confidence in a southern U.S. winter storm is increasing for
  Tuesday and Wednesday. Rain, wind, and dangerous beach/boating
  conditions will likely impact East Central Florida.

&&

.DISCUSSION...
Issued at 301 AM EST Sat Jan 18 2025

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

Across the state early this morning, surface analysis revealed a
developing warm front over the Space Coast, evidenced by a dew
point discontinuity. High pressure has quickly exited into the
Atlantic, and return (southerly) flow will become established
today as the warm front lifts north of Central Florida. This
evolution is in response to a shortwave trough over the Lower
Mississippi Valley.

Ensemble guidance is in strong agreement through Monday. A well-
defined branch of the subtropical jet will extend from Baja
California to the Deep South later today. To the east of a blocking
ridge over the far NE Pacific, a powerful jet streak is carving out
a trough over the Rocky Mountains. By Sunday, guidance indicates
that the polar and subtropical jet streaks will phase over the
Southeast U.S. as a chunk of the tropospheric polar vortex overtakes
the Great Lakes and Ohio Valley. Dense, cold, Arctic air is set to
plunge into the Central & Eastern U.S., driving a surface cold front
down the Florida Peninsula on Sunday. Along the front, total
moisture and integrated water vapor transport are forecast to exceed
the 99th percentile of climatology. The front settles into the
Florida Straits by Monday, with a large 1040+ hPa high-pressure axis
in its wake from the Mid-Atlantic to the Rockies.

For the first half of the work week, Florida is expected to reside
at the base of the deep trough encompassing much of the nation. An
additional shortwave, currently analyzed by the grand ensemble over
the Alaska Panhandle, is predicted by most (if not all) members to
descend into the Southwest by Monday before ejecting east toward
Florida by early Wednesday. In response, guidance tightens the
baroclinic zone over Florida, spawning a potential wave of low
pressure which would transit a sharpening front from late Tuesday
into early Wednesday. Ensemble spread is decreasing, leading to
higher confidence in impacts from this weather system for Florida.

By the end of the work week, cluster analysis exhibits broad
agreement that another trough digs into the Eastern U.S.
Persistent ridging along the West Coast would support this
outcome. Some members surge moisture back over the state ahead of
another cold front, but there are timing differences.

The trough late next week appears progressive, but model spread
remains high beyond the 7-day forecast. As mentioned in previous
discussions, some retrogression of the pattern is anticipated as we
close out January. This should lead to moderation of temperatures
if the N Pacific ridge can flatten and/or move westward. However,
with the core of the Arctic air remaining on our side of the
globe (near Hudson Bay), additional cold outbreaks are attainable.
The CPC outlook now slightly favors above-normal temperatures
between Jan 25-31.


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

Today-Sunday...

A few showers and plentiful clouds accompany the warm front as it
lifts overhead. Showers are forecast to exit this morning,
leaving us to mix out the stratus as the warm sector becomes
established. At least some sun breaks are forecast this afternoon,
allowing a warming trend with highs in the mid 70s to near 80F,
warmest south. Breezy SSW gusts from 15-20 mph can be expected.
Tonight should be quite mild with 60s area-wide.

Late tonight, the cold front will start to approach the peninsula.
As it does, showers and isolated lightning storms are forecast to be
entering Lake/Volusia counties by around sunrise. Through Sunday,
this band of rain and a few storms should settle southward through
East Central Florida. Rain chances Sunday range from 50% in Martin
County to 80-90% from Osceola/Brevard Counties northward. Ahead
of the front, breezy to windy conditions are still forecast, with
a reasonable high-end for wind gusts of 30-35 mph in the warm
sector. Our warmest temps will be along the Treasure Coast, in the
low/mid 80s.

The column looks unusually warm and moist ahead of the front, but
lapse rates near the boundary are not too impressive. This results
in MLCAPE values from 400-750 J/kg. Both low-level and deep-layer
shear are present, but it looks largely unidirectional and oriented
closely with the broken convective line. SPC has the district in a
Marginal (5%) severe risk, which is prudent considering this
setup. The main threat would be gusty winds where a line segment
can become more perpendicular to the shear. Given the marginally
favorable setup, the chance for a tornado is very small but non-
zero. The potential for excessive rainfall appears very low as well.

Sunday Night-Monday...

As the front slips south of us, colder air will take its place. By
Monday morning, we are forecasting quite a range of low temps, from
the upper 30s northwest of Orlando to the 50s near Port St Lucie.
Wind chills may briefly reach the lower 30s near Leesburg and
Daytona Beach. Breezy north winds persist on Monday, keeping the
chill in place. We are below statistical guidance for our northern
communities, holding Daytona Beach just below 50F. Orlando and
the Space Coast should only reach the mid 50s, with low 60s
relegated to the Treasure Coast.

Tuesday-Wednesday...

Confidence is increasing in unsettled weather, but the timing and
placement of rain coverage still differ. Broadly speaking, showers
should increase Monday night, with periods of rain likely (70%) on
Tuesday. Depending on where the sharpening front sets up will
determine the heaviest axis of rain; it`s still too early to know
this. Winds turn onshore, leading to warmer temps southeast of I-4
(60s, even nearing 70 for the Treasure Coast).

The mid-level disturbance responsible for this active weather is
predicted to move by on Tuesday night. This should force the front
southward while continuing the high rain coverage. The potential
for windy conditions is increasing along and just behind the
front. Statistical guidance supports a 60-70% chance of peak gusts
exceeding 35 mph along the coast. This will likely lead to
hazardous surf conditions Tuesday night into Wednesday.

Behind the boundary, colder air is drawn southward again, and
sunrise Wednesday temperatures are now forecast in the mid/upper 30s
northwest of Orlando. There remains a medium chance for wind chills
to briefly drop into the upper 20s over this area. Travelers
planning to head toward the I-10 corridor and northward may
encounter a rare winter storm with freezing rain, sleet, and snow.
Temperatures still look too warm for any winter weather impacts over
our forecast area. Rain showers should exit during the day on
Wednesday, leaving us brisk and chilly.

Rest Of Next Week...

Confidence is quite low as the mid-week system departs and another
disturbance approaches from the Central Plains. There should be
another opportunity for rain sometime from late Thursday into
Friday, but timing differences are quite large. Temperatures will
likely remain at least a few degrees below normal.

&&

.MARINE...
Issued at 301 AM EST Sat Jan 18 2025

A warm front lifts north of the waters today, with SSW winds
developing, up to 15 KT nearshore and 28-23 KT well offshore where a
Small Craft Advisory will be in effect through early afternoon.
Winds lessen slightly tonight, but ramp up again on Sunday ahead of
a cold front (WSW 15 KT nearshore, 18-23 KT offshore). Seas up to 3
FT nearshore, 3-5 FT offshore through the weekend. Rain chances
become high on Sunday, with isolated lightning possible. There is a
low chance for a brief wind gust over 35 KT near any storms. Behind
the cold front late Sunday night, winds veer northwesterly from 15-
20 KT. This will cause seas to build on Monday from 3-5 FT nearshore
up to 4-7 FT offshore and in the Gulf Stream.

By Tuesday, another front should develop near or over the local
Atlantic. A disturbance will push the front south of the waters on
Tuesday night, leading to strong to near-gale-force northerly winds.
The chance for gusts to gale force is increasing as well. Bottom
line, mariners should monitor the forecast as a period of dangerous
winds and seas is now forecast from late Tuesday into Wednesday.

&&

.AVIATION...
(06Z TAFs)
Issued at 1255 AM EST Sat Jan 18 2025

Warm front lifting northward across the terminals overnight will
spread MVFR/IFR CIGs northward with TEMPO LIFR possible. Brief
VSBY reductions (5-6SM) in -SHRA but the primary impact will be
the stratus. As the warm front lifts north of central FL by mid
day Sat, cloud CIGs will lift from south to north. IFR/MVFR CIGS
will linger longest across northern terminals (MCO/SFB/DAB) but
should return to VFR by 18Z or so. On Sat, winds will increase out
of the SW 10-15 knots with gusts 20-24kt as the warm sector is
established across the area.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  74  62  71  39 /  20  50  90  10
MCO  77  65  74  44 /  10  40  90  10
MLB  77  63  77  46 /  10  20  80  20
VRB  80  63  81  50 /  10  10  60  20
LEE  76  64  69  39 /  10  60  90  10
SFB  77  64  72  41 /  10  50  90  10
ORL  77  65  73  42 /  10  50  90  10
FPR  80  63  81  50 /  10  10  60  20

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory until 3 PM EST this afternoon for AMZ570-
     572-575.

     Small Craft Advisory from 4 AM to 7 PM EST Sunday for AMZ570-572-
     575.

&&

$$

DISCUSSION...Heil
AVIATION...Kelly