Marco Island, Florida Weather Forecast Discussion

297
FXUS62 KMFL 271149
AFDMFL
Area Forecast Discussion
National Weather Service Miami FL
749 AM EDT Sat Sep 27 2025
...New AVIATION...
.KEY MESSAGES...
Updated at 745 AM EDT Sat Sep 27 2025
- Potential Tropical Cyclone Nine is expected to become a
   Tropical Storm this weekend, likely by later this morning.
   However, no direct impacts are currently expected for South
   Florida.
- Probabilities are low (mostly under 10%) for tropical storm
   force winds across South Florida.
- Primary concern to watch for will be potential hazardous
   marine and beach conditions late this weekend into early next
   week.
- Please see the AFD below for additional information:
&&
.SHORT TERM...
(Today through Sunday)
Issued at 220 AM EDT Sat Sep 27 2025
Mostly clear skies and light and variable winds over the interior
early this morning will set up favorable conditions for patchy to
areas of fog this morning. Most likely areas to be impacted are the
typical locations along Alligator Alley, along with interior SW FL
and areas around the lake. Will monitor this during the early
morning hours.
As for the rest of the forecast this weekend, South Florida
currently sits between two separate troughs, one of which is a
shortwave across the SE CONUS and the other is a deeper circulation
that is currently Potential Tropical Cyclone Nine (PTC 9). PTC 9
is currently centered just off the northern coast of Cuba moving
NW at 8 mph and has maximum sustained winds of 35 mph from the
latest reconnaissance data. With South Florida being sandwiched
between these two separate areas of low pressure, the flow
pattern for today is going to be very weak and thus convection
will be diurnally driven by peak afternoon heating and the sea
breezes. With weak steering flows, some isolated urban and poor
drainage flooding will be possible across the east coast metro
areas.
PTC 9 is expected to slowly shift NW through the Bahamas region
Saturday night and into Sunday before starting to shift to a more
northerly track and away from South Florida as it gets caught up in
the upper level troughing pattern. It is also expected to become a
Tropical Depression by Saturday night and a Tropical Storm on Sunday
morning when the track begins to shift more northwards. Even as the
system strengthens this weekend, Tropical Storm force winds are not
likely for South Florida since the system is expected to be far
enough offshore. Probabilities for Tropical Storm force winds are
currently below 10-20% for the region.
Overall, the primary threat from PTC 9 right now looks to be
potential for heavy rainfall. East coast areas would be at highest
risk, but right now a reasonable worst case scenario (10% chance for
exceedance) for the next 72 hours across the east coast is 3-5",
which will likely not cause significant flooding concerns. However,
uncertainty still exists with the exact track and development of
PTC 9, so this will continue to be monitored. Regardless of
development and the system`s track, enough heavy rainfall can
occur that can lead to localized flooding this weekend.&&
.LONG TERM...
(Sunday night through Friday)
Issued at 220 AM EDT Sat Sep 27 2025
The beginning of the long term period Sunday night into Monday will
be characterized by the tropical system`s progression northwards
away from the area. Some lingering marine and beach hazards will be
possible as it moves northwards early next week, but otherwise a
quasi-zonal flow pattern is expected to develop for the early week
to mid-week period along with some drier air being filtered into
South Florida behind the tropical system`s departure. As a result,
rain chances drop pretty significantly to mostly 20-30% each day for
the Monday to Wednesday time frame next week. By the end of next
week, guidance is hinting at mid-level troughing development across
the SE states and Gulf region, which could lead to an increase in
PoPs. However, with this being at the tail end of the forecast
period uncertainty is rather high.
Daily high temperatures for early to middle of next week are
expected in the low 90s for most areas. By the end of next week, a
slight decrease to the mid and upper 80s for daily high temperatures
is expected across the region.
&&
.AVIATION...
(12Z TAFS)
Issued at 745 AM EDT Sat Sep 27 2025
VFR conditions prevail this morning as winds remain light and
variable. Easterly winds will develop later today. Slight chance
for showers and isolated thunderstorms develops this afternoon,
then decrease overnight before increasing again early Sunday
morning. Winds will remain breezy overnight, gradually backing and
becoming more northerly into Sunday.
&&
.MARINE...
Issued at 220 AM EDT Sat Sep 27 2025
Gentle south to southeast breeze over the Atlantic waters becoming
more northeasterly late today. West to northwest breeze is expected
over the Gulf waters. Seas in both the Atlantic and Gulf waters 2 ft
or less through Saturday before rising on Sunday as winds and swell
increase with the strengthening of a tropical wave in the
vicinity of the Bahamas. Scattered thunderstorms possible which
may result in locally hazardous winds and seas.
Depending on the location of the aforementioned system, hazardous
winds and seas are possible late in the weekend or early next week
in the Atlantic waters. Pay close attention to the forecast over the
coming days.
&&
.BEACHES...
Issued at 220 AM EDT Sat Sep 27 2025
Increasing swell due to a potential tropical system that may develop
in the vicinity of the Bahamas over the weekend may result in an
elevated risk of rip currents along the Atlantic beaches late in the
weekend and heading into next week.
&&
.PRELIMINARY POINT TEMPS/POPS...
Miami            91  78  88  76 /  50  40  60  30
West Kendall     91  77  89  75 /  60  30  60  30
Opa-Locka        91  78  89  76 /  50  40  60  30
Homestead        90  77  88  75 /  60  40  60  30
Fort Lauderdale  89  77  87  75 /  50  50  60  30
N Ft Lauderdale  90  78  87  75 /  50  50  60  30
Pembroke Pines   93  78  91  76 /  50  40  60  30
West Palm Beach  90  77  87  75 /  50  50  60  30
Boca Raton       91  77  88  74 /  50  50  60  30
Naples           91  77  91  76 /  30  20  50  10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
$$
SHORT TERM...Redman
LONG TERM....Redman
AVIATION...ATV

NWS MFL Office Area Forecast Discussion