Special Marine Warning 280, NWS Key West, FL

959 
FZUS72 KKEY 050454
MWSKEY

Marine Weather Statement
National Weather Service Key West FL
1254 AM EDT Fri Nov 5 2021

GMZ033>035-044-054-055-050530-
/O.CON.KKEY.MA.W.0280.000000T0000Z-211105T0530Z/
1254 AM EDT Fri Nov 5 2021

...A SPECIAL MARINE WARNING REMAINS IN EFFECT UNTIL 130 AM EDT...

For the following areas...
Hawk Channel and Straits of Florida from west end of Seven Mile
Bridge to 20 nm west of Dry Tortugas out 20 nm...
Gulf of Mexico from west end of Seven Mile Bridge to Halfmoon Shoal
out to 5 fathoms...
Gulf of Mexico including Dry Tortugas and Rebecca Shoal Channel...
Gulf Waters from East Cape Sable to Chokoloskee 20 to 60 nm out and
beyond 5 fathoms...

At 1254 AM EDT, a strong thunderstorm was located near Halfmoon Shoal
Light, moving north at 15 knots.

HAZARD...Wind gusts 34 knots or greater.

SOURCE...Radar indicated.

IMPACT...Expect wind gusts in excess of 34 knots, suddenly higher 
         waves, frequent lightning, and heavy downpours.

Locations in the warning include...
Twenty-Eight Foot Shoal Light, New Ground Rocks Light and Halfmoon
Shoal Light.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare for wind gusts in excess of 35 knots, steep and fast-building
seas, frequent lightning strikes, and blinding downpours. Stay low or
go below, and make sure all on board are wearing life jackets.

&&

LAT...LON 2437 8234 2440 8256 2488 8251 2483 8216
TIME...MOT...LOC 0454Z 197DEG 15KT 2459 8241 

HAIL...0.00IN
WIND...>34KTS

$$

JAM

Area Forecast Discussion
National Weather Service Key West FL
1029 PM EDT Thu Nov 4 2021

.DISCUSSION...
Currently - An upper trough, now aligned over the western Gulf of
Mexico, is sharpening as it continues to swing eastward.
Downstream of this trough is a west southwest to east northeast
jet that is supporting pressure falls in the central Gulf of
Mexico. This is all contributing to a broad zone of increasing
lift and moist confluent flow across our area. After paltry
showers affect the forecast area earlier this evening, clusters of
showers and thunderstorms have begun sprouting on our westernmost
zones.

Short Term Update - Overall, a few periods of well above normal
rain chances will begin tonight. The upper trough will push into
the central Gulf of Mexico overnight and the associated deepening
low will drive towards the northeastern to eastern Gulf of
Mexico. The Keys will remain within a broad zone of ascent with
continued moist confluent flow down low. Forecast soundings
suggest precipitable water will increase about a quarter of an
inch to around 2 inches, with gains occurring at most all levels.
Expect the shower and thunderstorm activity to gradually
proliferate and quite likely delivering rounds of heavy showers
and thunderstorms across the island chain. Surface through lower
level winds are expected to remain modest while steadily veering
southeasterly. The potential for severe thunderstorms is minimal
due to the rather weak wind fields and increasingly saturated
column. Temperatures should bottom out in the lower 70s with the
dew point much much below that, likely leading to a soggy morning
whether or not a location sees precipitation.

Looking a bit further out, the surface low will move across
Florida Friday night and early Saturday. Surface winds will
freshen out of the west to northwest. This will usher in the
first significant cool down of the season, particularly as winds
continue veering north over the ensuing days. The coolest
temperatures will be Sunday night through Tuesday night.

&&

.MARINE...
A developing low pressure system in the central Gulf of Mexico
will move towards the Florida coast overnight. This will result in
gentle to moderate easterly breezes shifting southeasterly. Expect
increasing shower and thunderstorm coverage through the night.

&&

.AVIATION...
Sub-VFR conditions may be possible at both the EYW and MTH terminals
during the next 24-hours as a cold front moves through our CWA later
tonight and tomorrow. Moreover, VCTS conditions are included in the
current terminal forecasts, however, the ending time will be
adjusted in future forecasts to be more precise. Otherwise, surface
winds will be out of the east-southeast between 5 to 10 knots.

Beyond the 24-hour period, in the wake of the frontal boundary,
winds will increase up to 18 knots, out of the north-northwest.

&&

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

&&

Public/Marine/Fire...11
Aviation/Nowcasts....KR
Data Acquisition.....AP

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Hazardous Weather Outlook
National Weather Service Key West FL
432 AM EDT Thu Nov 4 2021

FLZ076>078-GMZ031>035-042>044-052>055-072>075-050845-
Monroe Upper Keys-Monroe Middle Keys-Monroe Lower Keys-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
Bayside and Gulf side from Craig Key to west end of Seven Mile
Bridge-
Gulf waters from East Cape Sable to Chokoloskee 20 to 60 NM out
and beyond 5 fathoms-
Gulf of Mexico including Dry Tortugas and Rebecca Shoal Channel-
Gulf of Mexico from west end of Seven Mile Bridge to Halfmoon
Shoal out to 5 Fathoms-
Hawk Channel from Ocean Reef to Craig Key out to the reef-
Hawk Channel from Craig Key to west end of Seven Mile Bridge out
to the reef-
Hawk Channel from west end of Seven Mile Bridge to Halfmoon Shoal
out to the reef-
Straits of Florida from Ocean Reef to Craig Key out 20 NM-
Straits of Florida from Craig Key to west end of Seven Mile
Bridge out 20 NM-
Straits of Florida from west end of Seven Mile Bridge to south of
Halfmoon Shoal out 20 NM-
Straits of Florida from Halfmoon Shoal to 20 NM west of Dry
Tortugas out 20 NM-
Straits of Florida from Ocean Reef to Craig Key 20 to 60 NM out-
Straits of Florida from Craig Key to west end of Seven Mile
Bridge 20 to 60 NM out-
Straits of Florida from west end of Seven Mile Bridge to south of
Halfmoon Shoal 20 to 60 NM out-
Straits of Florida from Halfmoon Shoal to 20 NM west of Dry
Tortugas 20 to 60 NM out-
432 AM EDT Thu Nov 4 2021

This Hazardous Weather Outlook is for the Florida Keys and
adjacent coastal waters.

.DAY ONE...TODAY AND TONIGHT

Isolated thunderstorms are possible today, becoming scattered
tonight. The primary hazards associated with these thunderstorms
will be cloud to surface lightning strikes and wind gusts 30 to 40
knots.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

Scattered thunderstorms are possible Friday, becoming isolated
Friday night. The primary hazards associated with any thunderstorm
will be cloud to surface lightning strikes and wind gusts 30 to
40 knots.

Small Craft Advisories may be required for some or all of the
Florida Keys marine zones Saturday through Wednesday. The primary
marine hazards will be winds near 20 knots and seas exceeding six
feet, especially in portions of the Straits of Florida and
offshore Gulf of Mexico coastal waters.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.