De Leon Springs, Florida Weather Forecast Discussion

433
FXUS62 KMLB 251131
AFDMLB
Area Forecast Discussion
National Weather Service Melbourne FL
731 AM EDT Thu Sep 25 2025
...New AVIATION...
.KEY MESSAGES...
Issued at 314 AM EDT Thu Sep 25 2025
- Afternoon shower and lightning storm chances remain slightly
  below normal today, then increase the last couple days of the
  week.
- There is a High (80%) chance for tropical development of a wave
  over the next 7 days as it tracks north-northeastward across
  the northern Caribbean. However, forecast track uncertainty is
  higher than normal due to complicated interactions with other
  systems.
- Poor to hazardous beach and boating conditions early next week
  from this system are becoming increasingly likely, but it is
  too early to determine what if any other impacts East Central
  Florida could see given the amount of uncertainty.
&&
.DISCUSSION...
Issued at 314 AM EDT Thu Sep 25 2025
Today-Tonight...Ridge over the western Atlantic begins to retreat
in response to a deep positively tilted trough swinging across
the CONUS and into the eastern US. The surface high pressure
reflection of the ridge aloft holds mostly the same position
the next couple days before also retreating further out to sea,
keeping the surface ridge axis stretched towards South Florida. Light
south to southwesterly flow will subtly slow development of the
east coast sea breeze, shifting this evening`s sea breeze
collision to just east of the center of the peninsula, near the
Orlando Metro. Moisture has recovered a bit since yesterday, with
models showing PWATs ranging from 1.8-2.0" (near to slightly above
normal), but the 850-700mb layer crucial for updraft development
remains on the dry side. MUCAPE isn`t terrible at 1,000-1,500 J/kg
with bulls-eyes up to 2,000 J/kg, and MLCAPE has some respectable
1,000-1,500 J/kg bulls-eyes, but 500mb temperatures increasing to
around -5.5C and shallow lapse rates aren`t helping. Overall the
environment looks to support initially isolated showers and
lightning storms on the sea breezes in the afternoon and early
evening as they move inland, becoming scattered across the
interior in the late evening as the sea breezes and boundaries all
come together. A few stronger storms capable of occasional to
frequent cloud to ground lightning, gusty winds to around 45 mph,
and locally heavy rainfall are possible. Temperatures a bit on the
warm side as afternoon highs push towards the M90s inland and
L90s along the coast. There is a Moderate risk of dangerous rip
currents at the Central Florida Atlantic beaches. Always swim near
a lifeguard, and never swim alone.
Friday-Saturday...A mid-level low begins to develop over the
Southeast in the trough swinging through the eastern US, gradually
becoming cutoff by the weekend, causing it to slow down as it
approaches the Atlantic seaboard. This will drag a NNE-SSW
oriented cold front across the Florida peninsula and eastern Gulf,
which also stalls by the weekend over or very near Central
Florida. The highest moisture (PWATs +2") associated with the
front remain west of the area Friday, while a band of relatively
lower but still generally above normal moisture (PWATs 1.9-2.0")
is dragged across ECFL in offshore flow between the approaching
front and the ridge axis of the subtropical high extending
tenuously towards Central Florida. By Saturday the front
approaches the ECFL door step while the ridge axis lifts to the
north, bringing the higher moisture across the area. This will
support scattered to possible numerous showers and storms Friday,
becoming scattered to numerous Saturday, with the highest chances
across the north and along the coast as onshore flow ushers along
the west coast sea breeze while slowing/pinning the east coast sea
breeze, resulting in a sea breeze collision over the eastern side
of the peninsula. Overall afternoon instability doesn`t change
much from Thursday as MUCAPE values generally remain 1,000-1,500
J/kg with some bulls- eyes up to around 2,000 J/kg , but
contribution will shift from more low-level moisture but warmer
aloft Thursday to less low-level moisture but cooler aloft Friday
and Saturday, which could support some stronger storms capable of
occasional to frequent lightning strikes, gusty winds 45-55 mph,
small hail, and locally heavy rainfall. Temperatures start a
subtle downward trend as rain chances and cloud cover increase,
but remain slightly above normal in the U80s-L90s.
Sunday-Wednesday...The forecast picture becomes very complicated
the first half of next week as multiple weather systems over the
Southeast US and western Atlantic interact with each other. Aloft
the cutoff mid-level low slows or stalls over the Appalachians,
tenuously keeping troughing over Florida, and causing the decaying
frontal boundary to stall over North to maybe Central Florida.
18Z ensembles put AL94, which has a High (80%) chance of tropical
development during this period, in the northern Caribbean
somewhere between Cuba and The Bahamas as it moves north-
northeastward. Several hundred miles to the east of AL94, Tropical
Cyclone Humberto in the western tropical Atlantic tracks east-
northeastward 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. Generally
these interactions cause the two systems to rotate
counterclockwise around each other, with the stronger system
leeching off the weaker. The whole situation is further
complicated as these two systems then interact with the trough as
it pushes off the Mid-Atlantic seaboard, eventually ejecting this
mess northeastward, but it is unclear where and when. As a result,
there is lower then normal confidence in the forecast tracks of
AL94 and Humberto at this time.
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 development, poor to
hazardous beach and boating conditions are becoming increasingly
likely, but 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 314 AM EDT Thu Sep 25 2025
Today-Saturday...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 (80%) 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 2-4 ft this morning settle to
1-3 ft by Saturday morning. Chances for showers and lightning
storms gradually increase through the end of the week.
Sunday-Monday...There is very low 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 across the
Central Florida Atlantic waters by Monday are becoming
increasingly likely, with deteriorating conditions Sunday.
&&
.AVIATION...
(12Z TAFs)
Issued at 731 AM EDT Thu Sep 25 2025
Light and variable winds this morning across all the terminals,
with bouncy VIS and CIGs quickly improving at VRB and FPR. Winds
pick up out of the SW after 15Z across the interior terminals and
DAB, becoming easterly along the coast after 17Z as the east coast
sea breeze develops and across the interior after 20Z as the sea
breeze moves inland. VCTS will be possible, though confidence in
exact timing of activity remains low based on latest model
guidance. Continued to refrain from the addition of TEMPOs based
on this, so will continue to monitor and amend as needed through
the day. Winds are forecast to become light and variable
overnight once again, with mainly VFR conditions anticipated
through the period.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB  91  74  90  73 /  30  20  50  40
MCO  93  75  92  74 /  40  20  60  30
MLB  89  75  89  75 /  30  30  40  40
VRB  89  74  90  73 /  40  20  40  30
LEE  92  74  91  73 /  30  20  60  30
SFB  93  75  92  74 /  30  20  60  30
ORL  93  75  92  75 /  40  20  60  30
FPR  90  73  90  73 /  50  20  50  30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
DISCUSSION...Haley
AVIATION...Tollefsen

NWS MLB Office Area Forecast Discussion