Area Forecast Discussion
Issued by NWS Key West, FL

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
609
FXUS62 KKEY 231853
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
253 PM EDT Mon Sep 23 2024

...New DISCUSSION, MARINE, AVIATION...

.DISCUSSION...
Issued at 252 PM EDT Mon Sep 23 2024
KBYX radar has shown isolated showers throughout the Keys for most
of the day. Most of this activity has remained over the marine
area moving to the west near 10 knots. Temperatures along the
Island Chain are in the upper 80s to lower 90s with dew points in
the mid 70s. Weak high pressure remains in place along the Eastern
Seaboard with a developing area of low pressure in the
northwestern Caribbean Sea. As a result, marine platforms are
observing mainly east breezes near 10 knots with Island Chain
communities observing near 10 mph.

.FORECAST...
Upper level ridging coinciding with surface high pressure will
continue to dominate through the evening hours. Therefore, have
maintained the slight chance PoPs through this evening increasing
to chances (~40%) after midnight through Tuesday as moisture
starts to increase. The pressure gradient will also start to
increase across the region resulting in breezes gradually
strengthening over the next few forecast periods.

The remainder of the forecast period from Tuesday night through
the upcoming weekend will hinge on what happens in the
northwestern Caribbean Sea. The National Hurricane Center has
begun to issue advisories on Potential Tropical Cyclone Nine as of
11 am EDT this morning. Whatever becomes of this system in the
Caribbean, it is expected to make its closest pass to the Keys
Wednesday evening into early Thursday which is when we expect the
worst conditions from the storm to occur. While the core of the
storm is expected to remain well west of the Keys, the storms wind
field is expected to be rather large resulting in far reaching
impacts well away from the center. Breezes will pick up in earnest
starting Tuesday night and Wednesday throughout the Keys peaking
Wednesday night and Thursday which is when we expect any
potential Tropical Storm conditions to occur. Regarding rainfall,
the heaviest rainfall looks like it will occur during the
Wednesday through Thursday time frame with locally heavy rainfall
possible. The Weather Prediction Center (WPC) has the Keys in a
marginal risk for heavy rainfall Wednesday and Friday with a
slight risk for Thursday. In combination with the rainfall and
strong SE flow, this may act to further aggravate the already
running higher than normal tides. On the back end of the system as
it pulls away, we expect their to be a "tail" of the system which
may unfortunately stall across the Keys prolonging the wet
period. Stay tuned to the latest forecast and continue to check
back for the latest.

Residents and visitors in the Keys should continue to check back
for the latest forecast updates from the National Hurricane Center
and the National Weather Service office in Key West through the
upcoming week.

&&

.MARINE...
Issued at 252 PM EDT Mon Sep 23 2024
There are currently no watches, warnings, or advisories in effect
across the Florida Keys coastal waters. From synopsis, gentle
easterly flow across the Keys coastal waters this afternoon will
steadily increase tonight and Tuesday, as high pressure builds
along the Eastern Seaboard, and a tropical low develops in the
northwestern Caribbean Sea. Heading through the middle and later
part of the week, the forecast will depend on the development and
movement of this low. At this time, we expect fresh to strong east
to southeast breezes to develop late Tuesday, with strong
southeast winds peaking Wednesday night into Thursday as the
tropical system moves northward across the eastern Gulf of Mexico.
The strongest winds and highest seas are expected over western
sections of the Keys waters. Mariners should continue to closely
monitor the latest forecast updates during the next few days.

.COASTAL FLOOD...
A Coastal Flood Statement remains in effect for all of the Keys
island chain, as above normal tides continue. Boaters can expect
less clearance under fixed bridges, especially during the hours
around high tide.

&&

.AVIATION...
(18Z TAFS)
Issued at 252 PM EDT Mon Sep 23 2024
VFR conditions will prevail at both EYW and MTH for the rest of
today and into tonight. While a shower cannot be ruled out at
either terminal, high uncertainty in exact timing and location of
rain will keep mention out of either TAF for now. Near surface
winds will be out of the east at near 10 knots.

&&

.CLIMATE...
On this day in 1931, the daily record rainfall of 2.10" was
recorded in Key West. Precipitation records for Key West date back
to 1871.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  82  90  81  87 /  40  50  80  90
Marathon  82  90  81  87 /  40  50  80  90

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&

$$

Public/Marine/Fire...MJV
Aviation/Nowcasts....JAM
Data Acquisition.....DR

Visit us on the web at weather.gov/key

Follow us on Facebook and Twitter at:
www.facebook.com/nwskeywest
www.twitter.com/nwskeywest