Special Marine Warning 403, NWS Miami, FL

Area Forecast Discussion
National Weather Service Miami FL
415 AM EDT Wed Aug 25 2021

.DISCUSSION...

Short term (Today - Thursday):

Key Points:

1) Hazardous marine conditions are forecast during the short term
period, especially across the southern Atlantic waters and Gulf
waters off Mainland Monroe County where a Small Craft Advisory goes
into effect at 11 AM today.

2) There will be a high risk of rip currents along the east coast
beaches of South Florida from this morning through at least Thursday.

Deep-layer subtropical high pressure will remain centered over the
western Atlantic waters through the short term period, as a
mid/upper-level perturbation tracks westward along the southern
periphery of the ridge toward South Florida today. GOES-16 derived
precipitable water along with water vapor imagery loops show deep
moisture associated with this feature, which should gradually
overspread South Florida from the east beginning late this afternoon.
The increasing moisture and background ascent accompanying the
perturbation will support elevated shower and thunderstorm chances
from this afternoon through at least Thursday -- especially across
the eastern half of South Florida. A few strong showers and storms
will be possible during this time-frame, mainly over the Atlantic
waters and east coast metros. The primary concerns through the short-
term period will be hazardous marine and beach conditions due
strengthening easterly winds through Thursday (see marine and beach
sections below). Maximum temperatures will be near normal each day,
with lower 90s expected across the area.

Long term (Thursday night - Tuesday):

Models remain in fair agreement in showing a mid level perturbation
over SoFlo, which resembles a closed low in latest guidance, slowly
migrating NW and into the northern GOMEX Thursday night into Friday.
This allows for the ridge over the west Atlantic to expand back into
the area and keep SoFlo under a robust SE wind regime.

Enough deep moisture will linger in the wake of the perturbation to
combine with the easterly flow regime in order to favor showers
and storms over interior and west coast areas each afternoon
through early next week. Coverage will be in the high-end
scattered to numerous range, highest during the afternoon hours.

Expect high temperatures to remain hot, in the low 90s for much of
the area, and in the upper 80s for locations near the Atlantic
coast. Heat index values should reach the low-mid hundreds each
afternoon.

&&

.AVIATION(06Z TAFS)...

As a mid-level disturbance moves over the area from the east, shower
and thunderstorm chances will gradually increase by this afternoon
and remain elevated through the period. MVFR to IFR conditions will
be likely as gusty showers and storms overspread the east coast
terminals, though confidence in timing of impacts remains too low to
include restrictions at this time. Breezy/gusty easterly winds will
prevail through the period.

&&

.MARINE...

A weak disturbance will move across the area today and Thursday,
resulting in a strengthening pressure gradient and breezy easterly
winds across the local waters. Winds across the southern Atlantic
and Gulf waters off Mainland Monroe County will reach or marginally
exceed 20 knots with higher gusts from this morning through early
Thursday morning, and a Small Craft Advisory will go into effect for
these areas beginning at 11 AM today. Elsewhere, winds could
approach advisory levels, and small craft operators are urged to
exercise extra caution. Additional Small Craft Advisories may become
necessary for the northern Atlantic waters, Biscayne Bay, and the
Gulf waters off Collier County, though confidence in meeting or
exceeding advisory criteria is currently too low to issue these
advisories at this time. Shower and thunderstorm chances will remain
elevated as the weak disturbance moves across the area, especially
across the Atlantic waters where a few strong storms with locally
gusty winds and higher seas will be possible.

&&

.BEACHES...

There is a high rip current risk along the east coast beaches of
South Florida due to breezy/gusty easterly winds. Shower and
thunderstorm chances will gradually increase today, especially
across the east coast beaches through Thursday.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            91  78  91  80 /  50  60  60  30
West Kendall     92  76  92  78 /  50  60  60  30
Opa-Locka        91  77  91  78 /  50  60  60  40
Homestead        90  77  89  78 /  50  60  60  30
Fort Lauderdale  90  79  89  80 /  50  60  60  40
N Ft Lauderdale  90  78  89  80 /  50  60  60  40
Pembroke Pines   91  77  89  78 /  50  60  60  40
West Palm Beach  91  76  90  78 /  50  60  60  50
Boca Raton       90  77  89  79 /  50  60  60  40
Naples           94  76  92  76 /  30  40  70  30

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk from 8 AM EDT this morning through
     Thursday evening for FLZ168-172-173.

AM...Small Craft Advisory from 11 AM this morning to 2 AM EDT
     Thursday for AMZ651-671.

GM...Small Craft Advisory from 11 AM this morning to 2 AM EDT
     Thursday for GMZ657.

&&

Today through Thursday and Aviation/Marine...Weinman
Thursday Night through Tuesday...AR

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Hazardous Weather Outlook for South Florida
National Weather Service Miami FL
434 AM EDT Wed Aug 25 2021

AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676-
252045-
Lake Okeechobee-Biscayne Bay-
Coastal waters from Jupiter Inlet to Deerfield Beach FL out 20 NM-
Coastal waters from Deerfield Beach to Ocean Reef FL out 20 NM-
Waters from Jupiter Inlet to Deerfield Beach FL from 20 to 60 NM-
Waters from Deerfield Beach to Ocean Reef FL from 20 to 60 NM
excluding the territorial waters of Bahamas-Glades-Hendry-
Inland Palm Beach-Metro Palm Beach-Coastal Collier-Inland Collier-
Inland Broward-Metro Broward-Inland Miami-Dade-Metro Miami-Dade-
Mainland Monroe-Coastal Palm Beach-Coastal Broward-Coastal Miami-
Dade-Far South Miami-Dade-
Coastal waters from Chokoloskee to Bonita Beach FL out 20 NM-
Coastal waters from East Cape Sable to Chokoloskee FL out 20 NM-
Waters from Chokoloskee to Bonita Beach FL from 20 to 60 NM-
434 AM EDT Wed Aug 25 2021

...HIGH RIP CURRENT RISK EAST COAST BEACHES...
...HAZARDOUS MARINE CONDITIONS ATLANTIC AND GULF WATERS...
...A FEW STRONG STORMS POSSIBLE TODAY...

This hazardous weather outlook is for South Florida.

.DAY ONE...TODAY AND TONIGHT

Rip currents: There is a high risk of rip currents along the east
coast beaches of South Florida.

Thunderstorms: Scattered thunderstorms are forecast today, with
locally gusty winds, frequent lightning, and heavy rainfall possible.

Waterspouts: Waterspouts will be possible with showers and storms.

Wind: Sustained winds of 20 knots or greater with higher gusts are
forecast across portions of the Atlantic and Gulf waters today into
tonight, where a Small Craft Advisory goes into effect this morning.
Locally gusty winds will be possible with the stronger showers and
thunderstorms.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

Hazardous marine and beach conditions will continue through at least
Thursday due to enhanced easterly winds. A few strong storms will be
possible across the area as a mid-level disturbance moves through the
region.

.SPOTTER INFORMATION STATEMENT...

Widespread spotter activation is not anticipated, however individual
spotters are encouraged to report high wind, hail and flooding to
the National Weather Service forecast office in Miami.

For more information...visit the National Weather Service in
Miami website at www.weather.gov/miami.

Weinman