Astatula, Florida Weather Forecast Discussion

658
FXUS62 KMLB 260534
AFDMLB
Area Forecast Discussion
National Weather Service Melbourne FL
134 AM EDT Fri Sep 26 2025
...New AVIATION...
.KEY MESSAGES...
Issued at 152 PM EDT Thu Sep 25 2025
- Rain chances increase through late week as deeper moisture
  builds southward across central Florida.
- AL94 has a High (90%) chance for tropical development in the
  Central Caribbean and Southwestern Atlantic. However, forecast
  track uncertainty is higher than normal due to complicated
  interactions with other systems.
- Poor to hazardous beach and boating conditions are becoming
  increasingly likely early next week.
&&
.DISCUSSION...
Issued at 152 PM EDT Thu Sep 25 2025
Current-Tonight... Increasing moisture is evident by a deck of
cumulus clouds spread across central Florida early this afternoon.
The east and west coast sea breeze have developed, and scattered
showers have formed along the boundary from Melbourne southward.
The current forecast holds PoPs around 30-50% through the
remainder of the afternoon, supported by 12Z guidance available at
the time. However, this could be generous, and higher coverage
could be realized based on current radar trends and more recent
hourly mesoscale guidance. Dry air above 850mb should generally
keep activity shallow. However, model guidance continues to show
pulses of vorticity passing aloft. A few storms which could tap
into this localized energy aloft will be capable of occasional to
frequent lightning, wind gusts up to 45 mph, and locally heavy
rainfall.
So far this afternoon, temperatures have been observed in the upper
80s and low 90s. The increased moisture will support peak heat index
values between 100-104 degrees ahead of any showers and storms. Low
temperatures remain muggy in the low to mid 70s.
Friday-Sautrday...A mid-level trough moves across the eastern U.S.
late week. A low becomes cut off at the base of the trough,
weakening across the southeast U.S. At the surface, an associated
frontal boundary slides across the Florida panhandle, nearing
northeast Florida on Saturday. Deep moisture builds ahead of the
front, increasing rain chances locally (50-70%), and the greatest
coverage is currently forecast near and north of Orlando and Cape
Canaveral. A passing shortwave on Friday could help to reinforce
afternoon convection, and a few strong storms cannot be ruled out.
Strong storms on Friday will be capable of frequent lightning
strikes, wind gusts up to 55 mph, small hail, and rainfall
accumulations of 1-3". While storm hazards are not as confident on
Saturday, deep moisture, modest shear, and low-level instability
could still allow for an isolated strong storm capable of gusty
winds, lightning strikes, and localized heavy rainfall. Light
southwest flow will keep afternoon temperatures mostly in the low
90s. However, high temperatures may be limited to the upper 80s
north and west of I-4 depending on the proximity of the front. Low
temperatures continue to hold steady in the low to mid 70s.
Sunday-Wendesday (modified previous)...The forecast picture becomes
very complicated the first half of next week as multiple weather
systems over the Southeast U.S. and western Atlantic interact with
each other. Aloft the cutoff mid-level low slows and weakens over
the Appalachians, tenuously keeping troughing over Florida, and
causing the decaying frontal boundary to stall over North to maybe
Central Florida. Latest ensembles put AL94, which has a High (90%)
chance of tropical development during this period, in the northern
Caribbean somewhere between Cuba and The Bahamas early Sunday.
Several hundred miles to the east of AL94, Tropical Cyclone Humberto
in the western tropical Atlantic tracks west-northwestward along the
subtropical ridge, closing the gap between all these systems. Global
models continue to indicate some level of binary interaction
(Fujiwhara effect) between AL94 and Humberto as the latter
approaches the former early next week, though how much of this is
model behavior vs real world is unclear. The whole situation is
further complicated as these two systems then interact with the
trough as it pushes off the Mid-Atlantic seaboard. As a result,
there is lower then normal confidence in the forecast tracks of AL94
and Humberto at this time. Current ensemble trends are split
suggesting a slower storm could track more northeastward and away
from the Florida coast, while a slightly faster track could have a
more northward trend, paralleling offshore the Florida coastline.
Residents and visitors of East Central Florida should monitor the
forecast closely, and have their emergency plan and supplies in
place if needed, as AL94 will at the very least make an
uncomfortably close pass. Regardless of exact track, poor to
hazardous beach and boating conditions are becoming increasingly
likely as early as late Sunday night or early Monday. Given the
forecast uncertainty it is too early to tell what, if any,
additional impacts to East Central Florida could be seen.
Given the high degree of uncertainty, NBM/consensus is as good a
forecast as any. For now, the official forecast calls for onshore
flow that could become gusty along the coast in the afternoon from
sea breeze enhancement, supporting scattered onshore moving showers
and lightning storms, with overall chances near to slightly below
normal based on the current forecast trends. Highest chances along
the coast, gradually decreasing inland during the daytime hours.
Mostly dry conditions inland overnight, but the coast will keep a
low chance for continued onshore moving convection. Some gusty
squalls are possible if this activity comes in the form of organized
rain bands. Temperatures near to slightly above normal.
&&
.MARINE...
Issued at 152 PM EDT Thu Sep 25 2025
Today-Saturday (modified previous)...Generally favorable boating
conditions. Surface high pressure over the western Atlantic today
and Friday retreats northeast through the weekend as a weakening SSW-
NNE oriented front approaches from the west, expected to stall over
or just west of the Florida peninsula by the weekend. Between the
front and the high, a tropical disturbance (AL94) is forecast to
begin turning more north-northeastward as it tracks across the
northern Caribbean towards The Bahamas. This system has a High (90%)
chance of development over the next 7 days. Light southwesterly
winds in the later half of the nights and early mornings shift
easterly to southeasterly at 5-10 kts from the afternoons through
the early overnight with the sea breeze. Seas 2-3 ft settle to 1-3
ft by Saturday morning. Chances for showers and lightning storms
gradually increase through the end of the week.
Sunday-Monday (modified previous)...There is very high uncertainty
in the marine forecast early next week due to complicated
interactions between AL94 in the northern Caribbean, Tropical
Cyclone Humberto to the east in the western Atlantic, and a mid-
level trough pushing offshore of the eastern seaboard, resulting in
less the normal confidence in the forecast track of AL94 as it
tracks uncomfortably close to our local Atlantic waters. Mariners
should closely monitor forecast updates. Regardless of track and
development, poor to hazardous boating conditions are forecast
across the Central Florida Atlantic as early as Sunday night.
&&
.AVIATION...
(06Z TAFs)
Issued at 125 AM EDT Fri Sep 26 2025
CAMs have trended the anticipated sea breeze collision slightly
westward this afternoon. Current solutions suggest it occurring
north to south along a line near MCO/ISM/SFB, then drifting
convection offshore into the evening hours. The collision appears
to be fairly late in the day (after 22Z). Thus, lower confidence
in how much convection will sustain to push offshore and affect
MLB/TIX/DAB. So, have included VCTS at the interior sites, which
will be closest to the collision and VCSH elsewhere. This includes
LEE, which should remain well west of the collision.
To the south, the Treasure Coast terminals look to have an earlier
start and end to convection, with showers and storms developing
along the sea breeze by around 18Z and pushing inland through 22Z.
Due to the scattered nature of convection today, have not included
any TEMPOs at this time, though this will be monitored for future
updates. Light, generally southerly winds will become E/SE behind
the sea breeze and remain around 10 kts or less.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB  90  73  88  73 /  40  40  70  50
MCO  93  75  91  74 /  50  30  70  40
MLB  89  75  89  75 /  40  30  60  50
VRB  90  73  90  74 /  40  30  60  50
LEE  91  74  89  73 /  50  40  70  30
SFB  92  75  90  73 /  50  30  70  40
ORL  92  75  90  74 /  50  30  70  40
FPR  90  73  90  73 /  40  30  60  50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
DISCUSSION...Law
AVIATION...Leahy

NWS MLB Office Area Forecast Discussion