857
FXUS62 KMLB 240932
AFDMLB

Area Forecast Discussion
National Weather Service Melbourne FL
532 AM EDT Tue Sep 24 2024

.DISCUSSION...
Issued at 500 AM EDT Tue Sep 24 2024

Key Messages:

- Broad area of low pressure over the NW Caribbean has a high
  chance (near 100%) for tropical development as it lifts north
  into the eastern Gulf of Mexico this week and strengthens.

- Heavy rain and tropical storm-force winds are an increasing
  concern.

- A plume of deep moisture may remain behind and keep a threat for
  heavy rainfall into the weekend.

Today...Dry airmass will limit rain chances though lingering
moisture across the far south (Martin/Okeechobee counties) will
produce isolated showers. Prospect for deep convection (thunder)
looks too low to mention. A warm day with max temps in the lower
90s interior and upper 80s coast. Tonight...winds become SE and
increase a bit above the boundary layer. This should increase
shower chances and have added a slight chance for thunder.

Wed-Mon...Model guidance remains consistent in forecasting a
tropical cyclone developing in the NW Caribbean and lifting north
into the SE Gulf of Mexico while strengthening Wed-Thu. Confidence
on size, intensity and forecast track is gradually increasing.
This storm looks to have a large wind field once it matures,
extending far to the east of the center while in the Gulf of
Mexico. There is some along-track (timing) differences with the
GFS being the fastest and the ECMWF slowing down at least in the
first 36 hours with some meandering around the tip of the Yucatan
peninsula.

The GFS and ECMWF ensembles remain consistent showing an upper
ridge over the SW Atlc and a developing cut-off low over MO/AR
that steers this system north to north northeast up thru the
eastern Gulf of Mexico and across the NE gulf coast later this
week. While it is too early to describe specific impacts for EC
FL, heavy rainfall and tropical storm-force winds are becoming an
increasing concern. A few tornadoes will also be possible in the
rainbands.

Models show a brief dry slot across the area Thu night/early Fri
then a plume of deep moisture redevelops over the FL peninsula
late Fri into the weekend long after the tropical system has
departed. This would produce high rain chances and a continued
threat for heavy rainfall, on ground that may be largely
saturated. Offshore flow on Fri will produce hot temperatures in
the lower 90s even at the coast with peak heat indices 104-108.
Continued hot and humid this weekend with deep moisture supporting
scattered storms and heat indices 100-105. Some drier air is
forecast to move in Mon and lower rain chances.

We are in peak hurricane season. Check weather.gov/mlb and
hurricanes.gov for the latest updates, and take the time to
check on your hurricane preparedness kits and plans.

&&

.MARINE...
Issued at 500 AM EDT Tue Sep 24 2024

Today...Weak surface high pressure continues to drift further
into the western Atlc. Moderate E/ESE flow near 15 knots will
produce choppy seas of 3 to 4 feet with winds increasing 14-18
kts tonight. Will likely need a Caution headline tonight south of
the Cape. Lower coverage of showers today as drier air filters
down from the north. Seas 3-4 feet today-tonight building 4-5 ft
Tue and up to 6 ft Tonight in the Gulf Stream Cape southward.

Wed-Sat...Potential Tropical Cyclone Nine is forecast to continue
to develop and strengthen over the northwest Caribbean in the
next 24 hours, moving north into the eastern Gulf of Mexico mid
week. Boating conditions are forecast to deteriorate further Wed
into Thu as southeast winds increase 20 kts Wed and 25+ kts Wed
overnight into Thu with seas building 7-10 ft (peaking at 12 ft
offshore Volusia and Brevard Thu aftn/night). At least Small
Craft Advisories look likely by Wed aftn but it is possible
Tropical Storm Watches and Warnings will become necessary for much
of the Atlc coastal waters. Deep moisture lifting northward will
support a high coverage of showers and storms beginning late Wed
into Fri. Winds will become S/SW Fri and decrease 15-20 kts with
seas subsiding below 5 ft along the coast due to the offshore
component but remaining 6-7 ft offshore. Flow turns SW on Sat and
decreases below 15 knots and this will allow seas to fall below 5
feet offshore.

&&

.AVIATION...
(06Z TAFs)
Issued at 112 AM EDT Tue Sep 24 2024

Another quiet TAF period. E breezes 5-11 KT through mid morning,
then 8-14 KT with gusts to 15-20 KT in the afternoon. VFR
conditions prevail; slight chance of showers relegated to SUA.

&&

.PRELIMINARY POINT TEMPS/POPS...
DAB  89  77  89  78 /   0   0  40  60
MCO  92  76  90  78 /   0   0  60  60
MLB  89  79  89  79 /   0  10  60  70
VRB  89  78  89  79 /  10  10  70  70
LEE  93  75  90  76 /   0   0  50  60
SFB  91  76  89  77 /   0   0  60  60
ORL  92  77  90  78 /   0   0  60  60
FPR  89  78  88  78 /  20  20  70  70

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...Tropical Storm Watch for Lake, Seminole, Orange and Osceola
     counties.
AM...None.

&&

$$

DISCUSSION...Kelly
AVIATION...Heil