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fxus62 kmfl 140044 aaa 
afdmfl

Area forecast discussion...updated
National Weather Service Miami Florida
744 PM EST Fri Dec 13 2019

Aviation...
the weather should remain dry tonight over South Florida with
mostly VFR conditions in the ceiling and vis. However, ktmb, kfxe,
and kmia could see reduced, MVFR vis or ceilings with possible
fog development right around sunrise. At this time, will not
mention in the above taf sites as the uncertainly is still high.
Will let the night shift look into this more, as it gets closer
in the taf period.

&&

Update...
low pressure was developing over the northeastern Gulf of Mexico
this evening along a stationary front. The low is forecast to
move northeast across northern Florida tonight and into the
western Atlantic waters on Saturday. This will allow for a cold
front to develop in the Gulf of Mexico and move southeast towards
South Florida tonight before moving through the area on Saturday
afternoon.

The winds tonight will mainly be from the southwest direction at
speeds of 5 knots or less. This will keep the tropical moisture in
place over South Florida and allow for some patchy fog to develop
late tonight into early Saturday morning, mainly over the
interior areas, which could push into the southeast Metro areas of
South Florida early Saturday morning. Otherwsie, the rest of the
area should remain dry tonight.

As the front pushes through South Florida, some showers and a few
thunderstorms should affect the western areas in the morning hours
before shifting to the eastern areas in the afternoon. However,
the support for thunderstorms will be well northeast of the region
by the afternoon. Therefore, the thunder threat should dissipate
by the afternoon with mostly showers possible for the East Coast
Metro areas.

Rest of the forecast looks good at this time and no other changes
are planned.

&&



Prev discussion... /issued 339 PM EST Fri Dec 13 2019/

Short term...

This afternoon through Saturday night :

Scattered showers and a few thunderstorms will continue
throughout the remainder of this afternoon into the evening hours
as a cold front advances towards the region. A few mid-level
impulses also March through the region this afternoon and
overnight further aiding the development for activity. Best
coverage of showers/storms is forecast over the Atlantic and
across the eastern half of the peninsula, particularly Palm Beach
County with the southwest steering flow this afternoon. A few
storms out over the Atlantic could be fairly strong this afternoon
and evening, but southwesterly steering flow should keep them
offshore. Morning east winds finally veered from the S/SW this
afternoon as an area of low pressure pushes northeastward across
the peninsula and treks along the southeast Continental U.S. Coast. The
aforementioned cold front associated with this low will push
through South Florida tomorrow with showers, and perhaps a
thunderstorm or two. Forecast soundings do have relatively decent
cape and srh values across the local waters tomorrow morning so
wouldn't be surprised if brief areas of rotation were seen.
Otherwise, despite this being a rather impressive negatively
tilted trough, most upper-level support/dynamics and jet activity
stays well to the north of the area. Northwesterly to northerly
winds are expected in the wake of the front with slightly cooler,
but not too much, and drier air filtering in over the area. Low
temperatures Saturday night are forecast to drop into the low 50s
west of the lake to near 60 along the East Coast.

Long term...

Sunday through Monday...

High pressure will then build in over the southeast conus,
bringing a brief shot of cooler, drier air to South Florida. As
the high continues to slide into the western Atlantic, surface
winds will quickly veer out of the east on Sunday and then
southeast by Monday evening. This will help modify the airmass
and initiate a gradual increase in moisture through the
atmospheric column.

As mentioned, the cool down will be short-lived with Sunday
morning temperatures in the 50s across much of South Florida and
low 60s along the East Coast Metro, climbing Monday night into the
upper 50s to low 60s with the East Coast Metro in the mid to
upper 60s. Daytime temperatures will also be slightly cooler on
Sunday in the upper 70s across the area and low 80s along the
southwestern interior. Then in the low to mid 80s on Monday
afternoon.

Tuesday through Friday...

The mention of rain returns to the forecast on Tuesday as a
deepening low over the northeast Continental U.S. Pushes off the eastern
Seaboard, dragging the next frontal boundary down the peninsula
towards South Florida. While global models continue to differ in
the front's intensity, convective coverage should begin to
increase Tuesday ahead of the boundary and continue through the
day on Wednesday. Activity should consist of mostly scattered
showers with much of the upper level support for deeper convection
remaining well to the north. However, cannot rule out a few
rumbles of thunders.

Behind the boundary, coverage of showers will refocus across the
Atlantic waters with drier conditions elsewhere. Also in the wake
of the front, cold air will advect into South Florida with
overnight lows progged to dip into the upper 40s to low 50s across
the interior and Lake Okeechobee region and upper 50s to low 60s
along the East Coast on Thursday and Friday mornings. Daytime
temperatures will range from the low to mid 70s. Given the finer
details have yet to be resolved between individual global models
and their solutions, have gone with the blended approach for pops
and temperatures and will continue to monitor as we get closer in
time.

Marine...

Hazardous marine conditions continue for the Atlantic waters
through Saturday with seas remaining elevated in the Gulf Stream.
Winds may diminish overnight but are forecast to increase again
Saturday afternoon to advisory levels over the Palm Beach waters.
Passing showers and a few thunderstorms will be possible across
all waters today and tonight as a stalled front over the lake
region pushes northward. A cold front will push through the area
tomorrow, with northwesterly winds in its wake. Hazardous boating
conditions are expected to improve in the wake of this front.
However, another stronger front will push through around middle of
next week and may create hazardous marine conditions at that
time.

Aviation...

Generally VFR conditions are expected to prevail into this
afternoon, but some shower activity at times could cause some MVFR
conditions. Most models keep the heavier rain showers and ts offshore in
the Atlantic waters, but again, East Coast sites may see a passing
shower through 00z this evening with kpbi having the chance
through 04z. If ts were able to develop along the coast, kpbi has
the greatest potential, but due to low confidence, omitted from
tafs at this time. Winds gradually become southwesterly through
the period as a cold front approaches the region with breezy SW to
west winds tomorrow. Chances for rain showers exist tomorrow morning and
early afternoon, but again, low confidence on coverage and timing
is causing omission from tafs.

Beach forecast...

A high risk of rip currents is forecast for the Atlantic beaches
through at least Saturday evening as lingering swell continues to
affect the coast. Rough surf will also be possible for the Palm
beaches. Rip currents should improve some this weekend before
elevating again early next week with breezy east flow.
&&

Preliminary point temps/pops...
West Palm Beach 69 82 58 77 / 10 40 0 0
Fort Lauderdale 70 84 61 78 / 0 30 0 0
Miami 70 85 61 79 / 0 30 0 0
Naples 70 80 58 79 / 10 60 0 0

&&

Mfl watches/warnings/advisories...
Florida...high rip current risk through Saturday evening for flz168-172-
173.

Am...Small Craft Advisory until 7 PM EST Saturday for amz650-670.

GM...none.
&&

Update...54/bnb
marine...03/fell
aviation...54/bnb

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