Tropical Storm and Storm Surge in Florida, August 29, 2023

Area Forecast Discussion
National Weather Service Key West FL
635 AM EDT Tue Aug 29 2023

...New DISCUSSION, MARINE, AVIATION, TROPICAL SYSTEMS...

.DISCUSSION...
Issued at 630 AM EDT Tue Aug 29 2023

Idalia has become a hurricane as of the 5am advisory, with winds
of 75 mph. There have been no changes to the watches and warnings
from the previous advisory over the Keys or coastal waters. The
center of the storm is approximately 195 miles to the southwest of
Key West on a northern track moving near 14 mph (and possibly a
little faster than that in the past hour). On this track, the
storm is expected to pass well west of the Lower Keys on its way
towards the Big Bend region of Florida. Confidence in the track in
the first 24 hrs or so remains high. At this forward speed and
direction, the storm should pass north of our latitude sometime
this afternoon, passing well west of the Dry Tortugas.

Even though the center of the storm will pass well to the west,
the Keys may experience some impacts from Idalia. With prolonged
sustained south to southwest winds of around 20 knots for much of
the islands through Wednesday morning, coastal flooding is a
concern around times of high tide (especially on the Atlantic
side). Additionally, it is possible that the Lower Keys may be
impacted by a passing rainband as the storm moves northward,
resulting in a period of squally weather and tropical storm force
winds, mainly over the Lower or Middle Keys if this does indeed
occur. Even after the storm has passed well to our northwest, some
squally weather may be possible in lingering convection.

&&

.MARINE...
Issued at 630 AM EDT Tue Aug 29 2023

A Tropical Storm Warning is in effect for the westernmost Gulf
waters (west of the Halfmoon Shoal Light), and the deep Gulf
waters northwest of the Lower Keys outside of 5 fathoms. A
Tropical Storm Watch is in effect for the Florida Straits waters
south of the Lower Keys, and the Gulf waters north of the Lower
Keys out to 5 fathoms. A Small Craft Advisory is in effect for all
other waters, including Florida Bay. Winds across the area have
increased over the past several hours, with sustained 26 knot
winds currently measured at Sand Key Light, and 20 knot winds at
Sombrero. These winds are expected to stay up through Wednesday
morning.

&&

.AVIATION...
(06Z TAFS)
Issued at 630 AM EDT Tue Aug 29 2023

Windy conditions will prevail at both EYW and MTH today. Periods of
squally weather may pass over either terminal with the passage of
hurricane Idalia today. Impacts may include periods of MVFR CIGs,
MVFR to IFR VIS, and gusts in excess of 35 knots especially at EYW.
Short fuse amendments will likely be needed with the use of TEMPO
groups as the timing and location of incoming rain bands are highly
uncertain.

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 2 PM EDT Wednesday for FLZ077.

     Coastal Flood Warning until 2 PM EDT Wednesday for FLZ078.

     Tropical Storm Watch for FLZ078.

GM...Tropical Storm Watch for GMZ035-044-054-074.

     Small Craft Advisory until 5 AM EDT Wednesday for GMZ031-032-035-
     042>044-052>054-072>074.

     Tropical Storm Warning for GMZ033-034-055-075.

&&

Public/Marine/Fire...Devanas
Tropical Hazards.....11
Aviation/Nowcasts....JAM
Data Acquisition.....JAM

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Hazardous Weather Outlook
National Weather Service Key West FL
631 AM EDT Tue Aug 29 2023

FLZ076>078-GMZ031>035-042>044-052>055-072>075-301030-
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-
631 AM EDT Tue Aug 29 2023

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

.DAY ONE...Today and tonight.

A Tropical Storm Watch is in effect for the Lower Keys, as well
as the adjacent coastal waters. A Tropical Storm Warning is in
effect for the western waters, including the Straits of Florida
and the Dry Tortugas. Occasional squalls with tropical storm
force wind gusts will be possible today and tonight, especially
in and west of the Lower Keys. A few tornadoes in the outer rain
bands are possible as well. Small Craft Advisories are in effect
for all other Florida Keys.

A combination of the already elevated seasonal tides along with
Hurricane Idalia's strong southerly winds may produce coastal
flooding, with water levels of 1 to 2 feet above high tides over
the Lower and Middle Keys today. For the Upper Keys, minor to
moderate coastal flooding will be possible.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

A combination of the already elevated seasonal tides along with
Hurricane Idalia's strong southerly winds may produce coastal
flooding, with water levels 1 to 2 feet above average high tides
over the Lower and Middle Keys on Wednesday. For the Upper Keys,
minor to moderate coastal flooding will be possible.

Squally conditions trailing Hurricane Idalia may linger across the
Keys on Wednesday and maybe Wednesday night. Gusty winds, heavy
downpours, and cloud to surface lightning strikes will be the
primary impacts.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.