Merritt Island, Florida Weather Forecast Discussion

946
FXUS62 KMLB 240621
AFDMLB
Area Forecast Discussion
National Weather Service Melbourne FL
221 AM EDT Wed Sep 24 2025
...New KEY MESSAGES, DISCUSSION, MARINE...
.KEY MESSAGES...
Issued at 221 AM EDT Wed Sep 24 2025
- A High Risk of life-threatening rip currents continues through
  mid-week with long period swells from distant Hurricane
  Gabrielle.
- Scattered shower and lightning storm chances through late-week
  as deeper moisture settles over central Florida.
- Slightly above normal high temperatures for the interior
  through Friday reaching into the lower 90s each afternoon.
&&
.DISCUSSION...
Issued at 221 AM EDT Wed Sep 24 2025
Current-Tonight...Will again monitor early this morning for some
patchy fog potential north/west of I-4. Weak high pressure ridging
continues across ECFL over the next 24 hours. Light/variable winds
this morning surrounding the weak pressure gradient will, again,
transition onshore in the afternoon as the ECSB develops and moves
steadily inland.
PWATs generally near 2 inches and higher again this afternoon.
H500 temps (around -6.0C) and weak shortwave impulses will be
present aloft. For PoPs will go with 30pct along the Volusia/N.
Brevard coasts expanding to 40-50pct inland and southward across
the coverage warning area. Highest chances again southward and
well into the interior. Initial storm development again expected
along the sea breeze near the coast and will consist of ISOLD to
WDLY SCT convection with intensity and coverage increasing into
the interior thru late afternoon and early evening. Storm
steering flow continues to be very weak, with erratic movement
expected due to eventual numerous boundary collisions later today.
Primary lightning storm impacts remain occasional to frequent
lightning strikes, gusty winds locally up to 45-55 mph in
strongest storms, small hail, and locally heavy downpours which
could induce minor/nuisance flooding. Localized amounts of 1-3" in
a short period of time will be possible with a couple 4" totals
not out of the question.
Warm and humid conditions continue with highs in the U80s to around
90F near the coast and 90F to L90s inland. A few M90s within reach
near the Orlando metro and points further north/west. Peak heat
indices will approach 98-103F ahead of any potential shower or storm
development. Overnight low temperatures remain consistent in the L-
M70s.
Long period swell (~11 sec) from distant Hurricane Gabrielle
continues across the local Atlc waters and coastline. This will
promote numerous, strong, life-threatening rip currents at ALL
central FL Atlc beaches. Nice weather can be deceiving, and entering
the rough and dangerous surf is not advised! The HIGH rip current
threat persists through mid-week.
Thu-Fri...Mid-level troughing envelopes the eastern CONUS while on a
weakening trend, with medium range models now suggesting a closed
low developing aloft across the Tennessee/Mississippi Valleys
Fri-Fri night. The trend for this "troughy" pattern is to move
slowly towards the southeast U.S. At the surface, the low-level
ridge axis over central FL weakens and slides south/east away from
the area. A weak surface boundary will align across north FL and
the FL Panhandle towards the end of the period (Sat morning). Deep
moisture continues across the area on Thu, with drier air moving
into the region on Fri. There will continue to be daily sea
breezes with march inland each afternoon/early evening. Subtle
shortwave impulses embedded in the SWRLY flow aloft will aid
diurnal convection. Precip chances 50-70pct for Thu and 50-60pct
on Fri.
Max temps reach the U80s to L90s on Thu and U80s to around 90F
areawide on Fri. We will realize peak afternoon heat indices between
98-103F on Thu and 97-102F on Fri ahead of afternoon shower and
storm development. Low temps range from the L-M70s.
Sat-Wed...Getting interesting in the tropics as all eyes look toward
a potential tropical wave approaching the southern Bahamas early on
Sat, near the NE Bahamas late Sun, continuing a N trend parallel to
the FL coast on Mon (well offshore), and eventually NE Tue-Wed.
While this is still several days out consistency with models and
forecast confidence should improve as time draws near. At the very
least, interests in ECFL should be concerned regarding
marine/beach impacts. However, it remains a good reminder that we
are in peak hurricane season and to have an emergency plan in
place. Please continue to monitor the forecast for future updates.
Otherwise, the aforementioned mid-level low and associated vorticity
spins across the Southeast, Tennessee & Mississippi Valleys into
early next week while on a gradual weakening trend. There remains a
degree of uncertainty with both potential tropical development and
mid-upper level features during this period. This will also play
havoc with deep layer moisture so for now will continue PoPs in
the scattered category (30-50pct) as a hedge.
High temps generally in the U80s to L90s thru the period. Peak
heat indices generally in the 90s to near 100F each day, a bit
lower than recent days. Lows remain consistent and mild in the
L-M70s.
&&
.MARINE...
Issued at 221 AM EDT Wed Sep 24 2025
Today-Sun...The persistent long period ERLY swell from distant
Hurricane Gabrielle continues through mid-week, before gradually
diminishing into late week. Weak high pressure ridging across the
local waters will shift seaward with the approach of a weak front
this weekend. Will also be monitoring a tropical wave for
potential development near the Bahamas late in the period and into
early next week. For now, the pressure gradient remains fairly
weak with wind speeds AOB 15 kts outside of convection. We will
still witness sea breeze formation and push inland each afternoon.
The long period swell (~ 4ft) continues and will be hazardous at
inlets again today during the outgoing tide. Seas build 3-5 ft
today and 3-4 ft tonight. Wave heights diminish further into late
work-week and weekend, but may have to watch late Sun into early
next week as heights likely to build, once again, depending on
potential tropical formation (strength/location). Scattered
showers and lightning storms are forecast across the local waters
each day.
&&
.AVIATION...
(06Z TAFs)
Issued at 127 AM EDT Wed Sep 24 2025
Keeping an eye on early morning BR/FG potential for inland
terminals, particularly KLEE and tenuously including KMCO. LAMP
guidance continues to call for VFR but HRRR and HREF do have a
consistent but low (20% or less chance) for MVFR VIS reductions
between 08Z-13Z. Given low confidence held off mention in the
TAFs. Light/VRB winds shift Erly 5-10 kts after ECSB pushes
through, developing between 16Z-18Z, and colliding with the WCSB
INVOF KLEE and just west of KMCO/area terminals after 22Z,
assuming no interference from TS outflow. Initial TS possible on
the ECSB as soon as it develops. Chaotic boundary interactions
dictate convective evolution as activity generally pushes inland
while gradually increasing in coverage, but some TS could become
nearly stationary. Highest chances for TS along the ECSB/WCSB
collision late in the evening. Drier air from the north today
could undercut TS development, and confidence in timing and
coverage is lower than normal.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB  89  74  90  73 /  20  10  50  40
MCO  94  75  93  74 /  50  20  70  30
MLB  88  76  89  74 /  30  20  50  40
VRB  89  75  90  73 /  40  20  60  40
LEE  93  75  91  74 /  30  20  60  20
SFB  93  75  92  74 /  30  10  70  30
ORL  93  76  92  75 /  40  10  70  30
FPR  89  74  90  72 /  50  20  60  40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
&&
$$
DISCUSSION...Sedlock
AVIATION...Haley

NWS MLB Office Area Forecast Discussion