992
FXUS62 KMLB 201950
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
350 PM EDT Fri Sep 20 2024

...New DISCUSSION, MARINE...

.DISCUSSION...
Issued at 345 PM EDT Fri Sep 20 2024

KEY MESSAGES:

- The greatest potential (30-50%) for a few lightning storms this
  afternoon resides closer to the Treasure Coast. This weekend,
  30-40% shower/storm chances continue.

- Minor coastal flooding remains possible, particularly during the late
  morning high tides through the upcoming weekend. Low- lying
  streets, yards, and docks along the barrier islands and
  Intracoastal may experience minor flooding.

- There is a medium chance (50%) for tropical development in the
  northwest Caribbean or southern Gulf of Mexico next week. It is
  too early to determine what, if any, impacts this would bring to
  East Central Florida. Continue to monitor the forecast for
  updates.


Current-Tonight... A weak trough extending down the SE US coast and
over Florida will remain in place. East to northeast winds this
afternoon will be 10-15 mph with gusts up to 20 mph possible before
winds become light and variable overnight.  The GOES derived PW
imagery shows PW values ranging from 1.4-1.5" this afternoon across
east central Florida. This will continue to support isolated to
scattered showers and lightning storms this afternoon. The greatest
moisture will focus from Orlando/Cape Canaveral southward, with 20-
30 percent chance of showers/storms near I-4 and the Space Coast and
40-50 percent chances for the Treasure Coast. Main storm threats
this afternoon will be occasional to frequent lightning strikes,
gusty winds 40-45 mph, and brief torrential rain which could cause
minor flooding. Temperatures will be normal to slightly above normal
for this time of year, with mostly clear to partly cloudy skies.
Afternoon highs will be in the upper 80s to around 90 degrees.

A coastal flood advisory remains in effect for Volusia, Brevard and
the Treasure Coast through the period. The threat for minor coastal
flooding persists during high tide cycles.

Tonight, mostly dry conditions are expected with a few onshore
moving showers possible along the coast in the NE flow. Overnight
lows will be in the low to mid 70s under mostly clear skies.

Saturday-Wednesday... Upper level trough across the SE US coast,
including Florida will shift eastward away from Florida on Sunday as
a high pressure system over the TX region begins to migrate eastward
across the Deep south. This ridging will move over the Florida
peninsula early next week and remain in place through mid week. At
the surface, weak high pressure axis will remain over Florida
through early next week. This will result in lower moisture across
the local area, which will limit overall convection each day to near
to below normal for this time of year. The Central American Gyre is
still forecast to become active into mid next week. The National
Hurricane Center has highlighted an area in the NW Carribean that
has a medium chance (50 percent) of something forming over the
next 7 days.

East to northeast winds will persist over east central Florida
through mid next week. Wind speeds will generally be 10-15 mph with
a few gusts up to 20 mph possible each day. Near to below normal
rain chances are forecast through the time period, with models
indicating drier air filtering in across the area early next week,
which will further limit rain chances. Forecast PW values range from
1.5-1.8" this weekend, with values decreasing to 1.4-1.6" early next
week, with the higher values generally occurring across the south.
Thus, have maintained PoP 30-40 percent for much of the area through
the weekend, and 10-30 percent through early week. The highest rain
chances into early next week are generally across the south where
the higher moisture is.

Afternoon highs will be seasonable to slightly above normal for this
time of year, with highs in the upper 80s to low 90s each day. Due
to the lower humidity, heat indices will be in the mid to upper 90s.
Overnight lows will be in the low to mid 70s.

A coastal flood advisory remains in effect for Volusia, Brevard and
the Treasure Coast through Sunday. The threat for minor coastal
flooding persists during high tide cycles through at least Sunday.
The highest water levels are forecast in the late morning hours with
a lesser peak in the late evening. At the beach, the surf will be
slowly building and the rip current risk will be moderate to high!


Later Next Week... (Previous Discussion)

All eyes remain on the extended forecast as most ensemble members
and their respective means congeal deep tropical moisture and lower
surface pressures over the NW Caribbean or southern Gulf of Mexico.
Unfortunately, that`s about where the agreement stops. The National
Hurricane Center still highlights a 40% chance of tropical
development with this disturbance. At this time, however, there is
currently no well-defined system for models to track. Furthermore,
the mid-latitude longwave pattern will be in the process of
realignment. A weak trough is expected to push into the Midwest as
ridging builds over the West ahead of an enhanced Pacific jet. There
is a significant spread in the depth and timing of the Midwestern
trough and its embedded vort maxima. All told, one should not expect
a lot of clarity on this setup for 2-3 more days at least.

It`s still way too early to determine whether any local impacts from
this potential disturbance will occur. For now, we are showing a
gradual uptick in shower/storm chances late next week. Keep checking
weather.gov/mlb for updates over the next few days.


&&

.MARINE...
Issued at 345 PM EDT Fri Sep 20 2024

Current-Tuesday...(Modified Previous Discussion) Boating conditions
slowly become poorer over the next few days as onshore winds
increase. As high pressure settles into the Appalachians, northeast
winds freshen to 8-13 KT this afternoon and will persist through the
weekend. Isolated to scattered showers and a few storms possible
each day, especially from Cape Canaveral southward. By early next
week, winds turn more easterly at 10-15 KT. Seas 2-4 FT through
Saturday before building to 3-5 FT Sunday-Monday, and up to 6 feet
in the offshore waters on Tuesday, largely driven by a northeast
swell at 9-11 sec.


&&

.AVIATION...
(18Z TAFs)
Issued at 120 PM EDT Fri Sep 20 2024

VFR conditions are forecast through the period at all terminals.
Drier air is forecast to help limit convection across the area,
so confidence in activity near the terminals is lower today. Have
VCSH at the interior terminals and from MLB southward, with VCTS
at FPR and SUA. Will amend if needed. Winds remain out of the NE
around 10 knots, with occasional gusts up to 20 knots not able to
fully be ruled out. Any activity that does happen to pop up across
the peninsula should diminish after 00Z, with persistent NE winds
around 5 knots overnight. This continuous NE flow may prompt some
shower development across the local Atlantic waters overnight,
which could push onshore and lead to VCSH along the coastal
terminals. VCSH will continue along the coastal terminals through
Saturday morning. Winds pick up out of the NE between 5 and 10
knots after 14Z, with sites forecast to become gusty tomorrow
afternoon. Similar set up across the area, with lower confidence
in convective development beyond 18Z.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  74  88  74  88 /  20  30  10  30
MCO  74  89  74  90 /  10  30  10  30
MLB  75  88  76  89 /  20  30  20  30
VRB  73  89  74  89 /  20  40  20  40
LEE  73  89  73  91 /   0  20   0  20
SFB  73  88  74  89 /  10  40  10  40
ORL  74  90  75  90 /  10  30  10  40
FPR  73  88  74  89 /  20  40  20  40

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 2 PM EDT Sunday for FLZ141-154-159-
     164-347-447-647-747.

AM...None.
&&

$$

DISCUSSION...Watson
AVIATION...Tollefsen