381
FXUS62 KKEY 260823
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
423 AM EDT Wed Jun 26 2024

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

.DISCUSSION...
Issued at 423 AM EDT Wed Jun 26 2024

Scattered showers have developed during the late night hours
around the Upper Keys and over the offshore Gulf waters,
apparently along leftover island streamer boundaries that have
likely lurked since Tuesday afternoon. Temperatures along the Keys
island chain are mostly in the lower 80s, with dewpoints in the
mid to upper 70s, and winds on land from the southwest to west
around 5 mph. Surface analysis depicts weak high pressure over
the western Atlantic, with a ridge extending westward through the
Straits of Florida. Aloft, a weak trough remains in place over the
SW Atlantic, with a ridge extending eastward from Texas into the
central Gulf of Mexico. The 00Z Key West sounding sampled a very
moist and conditionally unstable airmass, with PW of 2.19 inches
which is above the 90th percentile for the date. Recent MIMIC-TPW
satellite imagery shows 2+ inch PWs remaining in place around the
Keys, while somewhat drier air intrudes into the northern and
eastern Gulf.

Weak WSW low level flow, ample moisture in place, and the lack of
a dominant ridge aloft all should favor island cloud line
development again today, with above average potential for
waterspouts. Accordingly, have maintained somewhat above climo 40
percent PoPs. However, have maintained just slight thunder
chances, as the rather warm temps aloft have resulted in little
lightning activity across our area during the past few days.
Otherwise, expect high temps to reach near 90, with sticky
dewpoints in the mid to upper 70s and light breezes making for a
typically oppressive late June day.

The ridge axis will begin to shift back northward across the Keys
on Thursday, shifting our steering flow to the SSW. This should
reduce the island cloud line potential, with best rain chances
probably occurring in downwind streamers over the Bay and Gulf
side waters. The lower to mid level ridge will also build westward
from the Atlantic across our area beginning on Thursday, likely
resulting in a somewhat suppressed convective pattern. Have kept
the existing 20-30 percent PoPs from Thursday through Friday
night, as the ridge should maintain more of an influence during
this period.

For the weekend and into early next week, the ridge aloft is
forecast to weaken, with moderate easterly low level flow across
our area to the south of the Atlantic ridge. With ample moisture
available, convection will be possible anytime but perhaps
favoring the night and morning hours. Have maintained 40 percent
PoPs from Saturday through Tuesday.

&&

.MARINE...
Issued at 423 AM EDT Wed Jun 26 2024

Overnight observations show SW/W breezes of 5 to 10 knots along
the reef and at Long Key C-MAN, with seas at Satan Shoal running
below 1 foot. Conditions will be favorable for cloud lines and
waterspouts across the nearshore waters around the Keys island
chain once again today. From the synopsis, a weak ridge axis will
extend westward from the western Atlantic across the Straits of
Florida today through Thursday morning, with light to gentle
southwest to west breezes prevailing over the Keys waters. Breezes
may become variable at times during this period. The ridge will
shift back northward Thursday afternoon through Friday, allowing
light southeast breezes to resume. Building high pressure over the
western Atlantic during the weekend will bring gentle to moderate
easterly breezes across the Keys waters.

&&

.AVIATION...
(06Z TAFS)
Issued at 423 AM EDT Wed Jun 26 2024

VFR conditions persist at EYW and MTH today. Light near surface
winds will remain westerly to southwesterly, indicating potential
cloud lines across the Middle and Lower Keys. TEMPOs will be issued
if showers develop near the island terminals.

&&

.CLIMATE...
On this day in 2020, a daily record warm low temperature of 86F was
measured in Key West. This measurement tied for the warmest low
temperature ever recorded in June. Temperature records for Key West
date back to 1873.

&&

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

$$

Public/Marine/Fire...Jacobson
Aviation/Nowcasts....AJP

Visit us on the web at weather.gov/key

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