493
FXUS62 KKEY 171916
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
316 PM EDT Thu Jul 17 2025

...New AVIATION, PREV DISCUSSION...

.AVIATION...
(18Z TAFS)
Issued at 302 PM EDT Thu Jul 17 2025
VFR conditions will prevail through the 18Z TAF period with only
FEW to SCT skies near FL025. Some isolated showers will continue
to transverse the forecast area tonight, specifically in the
vicinity of the Middle and Upper Keys. Therefore, opted to remove
VCSH from EYW completely, and only keeping VCSH for MTH until
18/00Z. East to southeasterly winds near 10 knots will see some
gusts near 20 knots overnight.

&&

.PREV DISCUSSION...
Issued at 1113 AM EDT Thu Jul 17 2025
Weather conditions look a lot friendlier compared to 24 hours ago!
Throughout this morning and early afternoon, isolated showers and
thunderstorms have been tracking northwestward across our local
waters, and have occasionally crossed the island chain. Automated
observations along our island communities have reported rainfall
amounts up to 0.12", but radar estimated rainfall totals suggest
some locations in the Upper Keys, where the heaviest showers have
occurred, have seen near half of an inch of rain along with wind
gusts near 20 mph. The lack of activity compared to yesterday
likely stems from reduced moisture across the area. Our 12Z
sounding calculated a PWAT value of 1.97" which is just below the
75th percentile value of 1.99", but CIMSS MIMIC Layer PWAT
suggests that this value isn`t entirely representative of the air
mass aloft. Values from CIMSS across the area range from
approximately 1.5" to 2.0".

This trend of spotty shower and thunderstorm development will
continue through today, and an increase in areal coverage isn`t
expected as the atmosphere becomes worked over. The inherited
forecast advertises 30 percent PoPs, and we will go ahead and keep
them due to radar trends showing development heading toward the
island chain. This activity won`t lead to a washout necessarily,
and anyone running into these showers may only have to wait 15 to
30 minutes for them to pass. No changes will be made to the
current forecast package.

&&

.MARINE...
Issued at 1113 AM EDT Thu Jul 17 2025
A strong area of high pressure will build westward across the
North Atlantic towards the Florida Peninsula, supporting
freshening east to southeast breezes over the next several days.
Small Craft Should Exercise Caution headlines will likely need to
be posted for portions of the Florida Keys coastal waters
beginning as early as this evening, possibly lasting through
Friday.

As a second, weak area of high pressure builds over the
eastern Gulf for the second half of the weekend through early next
week, east to southeast breezes will slacken, becoming light to
gentle.

&&

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

$$

Public/Marine/Fire...DP
Aviation/Nowcasts....DP
Data Acquisition.....DP

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