Special Marine Warning 33, NWS Key West, FL

Area Forecast Discussion
National Weather Service Key West FL
1031 AM EDT Tue Apr 20 2021

.DISCUSSION...
Currently - A lower level trough arcing north and northeastwards
into South Florida, along with the Atlantic ridge reaching across
Cuba, is generating moderate south to southwest breezes across the
Keys and surrounding waters. This warm muggy flow has resulted in
hints of summer weather with temperatures moving up through the
80s and dew points in the mid 70s. Rich lower level moisture in
excellent confluent flow is primarily responsible for a band of
showers and thunderstorms across the southeastern Gulf of Mexico
and nosing into the Fort Myers region and clipping our deep gulf
zones.

Short Term Update - A significant percentage of the lower level
trough emanating out of the Yucatan will bleed northeastwards
across Florida this afternoon as weak high pressure expands into
the Gulf of Mexico. This will translate into decreasing south
breezes shifting southwesterly. South to southwesterly lower
level flow will result in a Cuban shadow that will limit shower
activity near the island chain to slight at best. The persistent
band of showers and thunderstorms across the southeastern Gulf
should remain away from the Keys, but as long as they persist,
will continue to stream upper level clouds across the Keys.

&&

.MARINE...
A ridge axis across Cuba will result in generally south to
southwest breezes across Keys waters this afternoon. Winds will
trend downwards as troughing across the southeastern Gulf of
Mexico weakens and Cuba warms. Winds on the Florida Straits will
become variable. Will adjust first period wind transition wording
in the morning marine update.

&&

.AVIATION...
VFR will prevail at the EYW and MTH terminals through the afternoon,
although debris from thunderstorm anvils well to the west, will
retain sheaths of thick cirrus. We will reassess the chances for
Cuba to send storms to the northeast later this afternoon.

&&

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

&&

Public/Marine/Fire...11
Aviation/Nowcasts....CLR
Data Acquisition.....Williams

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Hazardous Weather Outlook
National Weather Service Key West FL
445 AM EDT Tue Apr 20 2021

FLZ076>078-GMZ031>035-042>044-052>055-072>075-210845-
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-
445 AM EDT Tue Apr 20 2021

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

.DAY ONE...TODAY AND TONIGHT

For early this morning, locally heavy rainfall, with amounts
ranging from a half to as high as 3 inches are expected on the
island of Key West. For the rest of today, no hazardous weather
is expected at this time.

Elsewhere, isolated thunderstorms are possible on the outer
waters of Mainland Monroe to the waters in and around Dry
Tortugas.

The primary thunderstorm hazard will be cloud to water lightning
strikes.

For tonight, isolated thunderstorms are possible. The primary
thunderstorm hazard will be cloud to surface lightning strikes.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Isolated thunderstorms are possible Wednesday and early Wednesday
night, otherwise, no hazardous weather is expected thereafter.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.