Special Marine Warning 111, NWS Key West, FL

003 
FZUS72 KKEY 131456
MWSKEY

Marine Weather Statement
National Weather Service Key West FL
1056 AM EDT Tue Jul 13 2021

GMZ073-131505-
/O.EXP.KKEY.MA.W.0111.000000T0000Z-210713T1500Z/
1056 AM EDT Tue Jul 13 2021

...THE SPECIAL MARINE WARNING WILL EXPIRE AT 1100 AM EDT...

The affected areas were... 
Straits of Florida from Craig Key to west end of Seven Mile Bridge 20
to 60 nm out...


LAT...LON 2398 8048 2383 8054 2390 8110 2422 8108
TIME...MOT...LOC 1455Z 103DEG 27KT 2394 8079 

$$

LIW

Area Forecast Discussion
National Weather Service Key West FL
416 AM EDT Tue Jul 13 2021

.DISCUSSION...
Partly cloudy, breezy and warm conditions prevail across the
Florida Keys on this early Tuesday morning. Radar during the night
has shown multiple arcing bands of showers and isolated storms
moving quickly northwest through our area. These bands have been
accompanied by wind gusts around 30 knots. Temperatures along the
island chain are hovering around 80 degrees, and winds on land
are from the east to southeast at 15 to 20 mph with occasional
higher gusts. Surface analysis depicts subtropical high pressure
centered near Bermuda and extending westward across north Florida.
Aloft, a strong subtropical ridge is centered between Bermuda and
North Carolina, with a weak upper trough sliding slowly northward
across Florida. The 00Z Key West sounding sampled ample
instability, with steeper than normal mid-level lapse rates due
to the presence of the trough aloft, no significant inversions,
and near normal PW of 1.80 inches. However, MIMIC-TPW satellite
imagery shows an area of enhanced moisture, with estimated PW
values around 2 inches, spreading westward into the Keys. This
area of moisture extends a few hundred miles eastward through the
Bahamas.

Today, a combination of the nearby upper trough and copious
tropical moisture streaming into our area along with brisk
easterly flow should provide well above normal rain chances. The
exact timing remains somewhat murky, but recent radar trends, the
latest HRRR, and much of the SPC HREF CAM guidance suggests that
we may see a relative lull this morning, followed by another round
of more active convection late in the morning into the afternoon.
Overall, any given location stands a quite good chance of seeing
some measurable rain during the day, and have nudged PoPs up to
60-70 percent. Max temps should be held down slightly by cloud
cover and rainfall, reaching the mid to upper 80s.

We may see one more round of scattered to widespread convection
this evening, followed by decreasing rain chances late tonight as
a drier airmass begins to edge into our area from the east. A much
more typical July weather pattern will return by Wednesday, with a
good deal of sunshine, highs climbing to near 90, and only low
chance (30 percent) PoPs, which are near the climatological
average.

Largely typical mid summer weather should then prevail through
the rest of the week and the weekend, as the subtropical ridge
remains dominant at the surface and aloft over the western
Atlantic and the Southeastern states. The only divergence from the
July norm will be moderate to occasionally fresh easterly flow,
rather than the typical light to gentle breezes. With the
suppressing ridge aloft remaining to our north and some extra
momentum in the boundary layer over the very warm waters of the
Straits, will maintain slightly above climo PoPs of 30 to 40
percent.

&&

.MARINE...
Overnight observations show generally fresh E/SE breezes across
the Keys coastal waters, with peaks and lulls due to periodic
outflow boundaries moving through the area. Similar conditions
should continue today, and Small Craft Exercise Caution (SCEC)
headlines will remain posted for all marine zones. Winds and
seas will be higher in and near scattered to numerous showers and
storms, and we will likely see some additional large outflow
boundaries cause temporary wind surges. A decrease to mainly
moderate breezes is expected late tonight and Wednesday. High
pressure over the western Atlantic and Florida will then maintain
moderate to occasionally fresh easterly breezes across the Keys
waters through the rest of the week and into the weekend, with
SCEC headlines potentially needed at times.

&&

.AVIATION...
VFR conditions will prevail both EYW and MTH island terminals
through 06z Wednesday morning. There appears there will be a lull in
shower and thunderstorm activity through at least the mid-morning
hours. However, showers and thunderstorms are expected to redevelop,
capable of producing MVFR ceilings and bouts of IFR visbilities at
either terminal. Specifics on timing are too uncertain, so have only
retained mention of VCSH at this time. This will be left to later
TAF routine issuances and possibly frequent amendments as conditions
require. Near-surface winds will be east to southeast near 15 knots
with frequent gusts near 20 knots outside of convection.

&&

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

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

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Hazardous Weather Outlook
National Weather Service Key West FL
418 AM EDT Tue Jul 13 2021

FLZ076>078-GMZ031>035-042>044-052>055-072>075-141000-
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-
418 AM EDT Tue Jul 13 2021

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

.DAY ONE...TODAY AND TONIGHT

Scattered thunderstorms are expected across the Florida Keys and
surrounding coastal waters today into tonight. The primary
thunderstorm hazards will be strong gusty winds and frequent
lightning strikes.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

Isolated thunderstorms will be possible through the period. The
primary thunderstorm hazards will be lightning strikes and locally
gusty winds.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated.