Coastal Flood and Strong Wind in Florida, December 21, 2018

Area Forecast Discussion
National Weather Service Miami FL
626 AM EST Fri Dec 21 2018

.AVIATION...
Mostly quiet weather, with the exception of a few SHRA this
morning, and windy conditions through the day as the main cold
front approaches the area. Gusts may reach to around 35 to 40 kts
at times. By this evening, the wind is forecast to relax, and the
the front is progged to make it through in the early morning
hours.

&&

.PREV DISCUSSION... /issued 316 AM EST Fri Dec 21 2018/

DISCUSSION...

TODAY AND TONIGHT: Large storm system will move north across the
Carolinas and Mid-Atlantic today as a potent surface low as its
parent upper level trough and low also lift northeast. Last
significant upper level vort rotating around the base of the trough
will push through this afternoon. So while the main frontal boundary
is moving into the west Florida coast early this morning, rather
than bringing the end to the showers, instead there will be an
upswing in showers behind it through early this afternoon.

Most significant weather feature today will be the strong west-
southwest winds behind the main front. Sustained winds are expected
to be around 20 to 30 mph across the region, with frequent gusts up
to 40 mph, especially the first half of the day. A Wind Advisory is
in effect for all of South Florida through this evening. This will
make for a somewhat windy and chilly day as temps only reach into
the upper 60s and low 70s.

As the main upper trough lifts out, it will bring through a
secondary frontal boundary that will bring an end to the showers as
winds veer northwest and cooler and drier air push in. Colder
overnight lows will drop into the mid 40s across the interior, and
low to mid 50s for the Gulf and Atlantic coasts.

THIS WEEKEND: Cool and dry weekend ahead as high pressure builds
across the state. Highs will struggle to get into the 70s both days,
though Sunday will be a little warmer as the high center slides east
and flow becomes more northeast. Expect Saturday night to be the
coldest with the high center directly overhead, with low in the low
40s over the interior, mid to upper 40s across the Gulf coast, and
upper 40s and low 50s for the Atlantic coast. Patchy frost may
become a concern over Glades/Hendry/N Collier if the forecast trends
a few degrees colder.

NEXT WEEK: Gradual warm-up of temperatures across South Florida as
we head into Christmas week with Christmas Day near normal in the
upper 70s and low 80s. Prevailing flow will veer more southeasterly
as high pressure slides into the western Atlantic, bringing a
gradual return of shower chances mid to late week. For now, do not
expect any significant frontal passages for South Florida through the
end of the forecast period.

MARINE...West-southwest gales will continue across all the local
waters through the day, with prevailing speeds 30-35 knots and gusts
to 45 knots possible, especially in the open Gulf and Atlantic.
Expect seas to peak at 16-20ft in the offshore Gulf and 9-13ft in
the offshore Atlantic later today. A Gale Warning remains in effect
for all local waters through late tonight.

Winds will gradually subside late tonight with NW winds 10-15kts by
Saturday afternoon. Seas will be slower to respond, and it will
likely take until Saturday night for seas to drop below hazardous
levels.

Expect more benign boating conditions into the Christmas holiday,
with seas 2-3ft and east-northeast winds 10-15kts. Stronger east
flow may bring cautionary conditions by mid next week.

BEACH FORECAST...Seas are expected to peak across the local waters
late this afternoon, with surf heights along the Gulf expected to
reach 6 to 9 feet, driven by the ongoing west-southwest gales.

This will exasperate what are already the highest high tides of the
month, leading to minor coastal flooding along the Gulf coast with
the next few high tides. Models suggest that the coastal flooding
threat will linger with the high tide cycle tonight given seas will
still be elevated, so have extended the Coastal Flood Advisory
through late tonight.

In addition to the Coastal Flood Advisory, a High Surf Advisory
remains in effect for the Gulf coast, and a High Risk of Rip
Currents for all South Florida beaches.

Given the offshore flow component, it looks like the Atlantic coast
will remain below high surf criteria of 7ft along with a minimal
coastal flood threat. However, this will continue to be monitored.

&&

.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach  70  52  66  48 /  20  10   0   0
Fort Lauderdale  72  55  68  54 /  20  10   0   0
Miami            72  55  69  54 /  20  10   0   0
Naples           68  54  67  48 /  40  20   0   0

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Wind Advisory until 1 AM EST Saturday for FLZ063-066-067-070-071-
     073.

     Wind Advisory until 1 AM EST Saturday for FLZ068-069-072-074-075-
     168-172>174.

     High Rip Current Risk through this evening for FLZ168-172-173.

     High Rip Current Risk through Saturday afternoon for FLZ069.

     High Surf Advisory until 4 PM EST Saturday for FLZ069.

     Coastal Flood Advisory until 4 AM EST Saturday for FLZ069.

AM...Gale Warning until 4 AM EST Saturday for AMZ610-630-650-651-670-
     671.

GM...Gale Warning until 4 AM EST Saturday for GMZ656-657-676.

&&

DISCUSSION...88/ALM
MARINE...88/ALM
AVIATION...13
BEACH FORECAST...88/ALM

Hazardous Weather Outlook for South Florida
National Weather Service Miami FL
357 AM EST Fri Dec 21 2018

AMZ610-630-650-651-670-671-FLZ063-066>075-168-172>174-GMZ656-657-676-
212100-
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-
357 AM EST Fri Dec 21 2018

...HAZARDOUS MARINE CONDITIONS FOR ALL SOUTH FLORIDA WATERS TODAY...
...WIND ADVISORY IN EFFECT FOR ALL SOUTH FLORIDA TODAY...
...HIGH SURF AND COASTAL FLOODING POSSIBLE FOR THE GULF COAST...

This hazardous weather outlook is for South Florida.

.DAY ONE...TODAY AND TONIGHT

Rip currents: There is a high risk of rip currents for all South
Florida beaches today.

Wind: The wind over the South Florida waters is forecast to exceed 30
kts, with frequent gusts of around 45 kts possible. A Gale Warning is
in effect for all South Florida waters. The wind across the mainland
is forecast to be sustained at around 25 mph with gusts of up to
around 40 mph possible through the day.

Flooding: There is a Coastal Flood Advisory in effect for Collier
County, and a statement for Mainland Monroe coast. Minor to moderate
flooding is possible today. Traditionally vulnerable locations along
the Southwest Florida coast could see inundations of 1-2 ft (with
2-3 ft possible across portions of the Collier coast). Period of
greatest threat is around high tide.

Waves: Seas of 12 to 18 feet are forecast today for the Gulf waters.
For the Atlantic waters, seas of 6 to 8 feet in the near shore
waters, and seas of 8 to 13 feet are forecast for the off shore
Atlantic waters today and tonight.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

Seas in the off shore gulf waters will subside on Saturday, but are
still forecast to run 7 to 9 feet through at least the morning hours.
Until the seas subside substantially, minor coastal flooding may
continue on Saturday for the Gulf coast.

Apparent temperatures Sunday morning are forecast to be in the mid to
upper 30s for the western Lake region, mid 40s for the gulf coast,
and around 50 to the lower 50s for the Atlantic metro areas.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

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