Area Forecast Discussion
Issued by NWS Miami, FL

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FXUS62 KMFL 231508
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
1008 AM EST Mon Nov 23 2020

.Update...
A broad shield of low-level stratiform cloud cover exists over
interior and western portions of South Florida. Daytime heating is
working to dissipate this cloud-cover via low-level mixing, as
temperatures in the 77-80F range should be sufficient to break a
relatively weak subsidence inversion at 850 hPa (evident on the
12Z MFL sounding). Aside from this, isolated showers are possible
over the Atlantic coast today, mainly in the afternoon.

&&

.Prev Discussion... /issued 648 AM EST Mon Nov 23 2020/

Aviation (12Z TAFs)...
VFR conditions are forecast to prevail through the day today. A
swath of low-level stratus clouds encompasses western and
interior portions of the region. IFR/LIFR conditions are likely
near/within this larger cloud field, with burn-off anticipated
around 14Z. Winds generally N becoming NE across all TAF sites,
with isolated SHRA possible along the east coast.

Prev Discussion... /issued 159 AM EST Mon Nov 23 2020/

Short Term (Today through Tuesday)...

Models depict drier air intrusion at the mid levels today, ahead of
an approaching sfc frontal boundary currently moving into the
Florida Panhandle. Model dew points show values in the mid 60s to
around 70 to start the day, then gradually dropping with the drier
air advection. Meanwhile, a sfc trough moving across the area will
back winds to am ore N/NE flow today, with speeds increasing to the
10-15 mph range at times along the Atlantic coast.

Showers will likely remain confined to the immediate coastline
across the Atlantic side, but will still stretch some 15-20 POPs
along the east coast metro areas in case a few showers do develop.
The rest of SoFlo should be in single digits for POPs as the drier
air establishes over land.

The persisting high pressure over the SE CONUS will erode and give
way to the aforementioned front to move across the peninsula, which
should be reaching central Florida this afternoon, then crossing
SoFlo later tonight and through Tuesday morning.

Even drier air will descend upon the area starting Tuesday afternoon
in the wake of the FROPA. High pressure expands across the SE CONUS,
Florida and the eastern Gulf, with no rain expected. Winds veer to
the NE then ENE by Tuesday evening as the high pressure becomes the
dominant synoptic feature.

Temperatures will remain at or slightly above normals with afternoon
highs in the low-mid 80s.

Long Term (Tuesday Night through Early Next Week)...

Plump mid-upper level ridging across our area Wednesday will
gradually displace eastward through the remainder of the work week
in response to a trough and associated low pressure system
progressing across the eastern CONUS. At this time, model consensus
continues to keep a cold front associated with the aforementioned
low well to the north of South Florida. As the high slides
eastward, upper-level zonal flow governs across the region (with
westerly winds). At the surface/low-levels, easterly winds
prevail. Although forecast derived PW`s remain around 1.0 to 1.4
inches through the first half of the extended period, isolated
showers along the Atlantic waters and adjacent coastal areas will
be possible due to the aforesaid easterly winds, albeit shallow in
nature. Due to sparse coverage and the shallow, swift moving
nature of the showers, forecast continues to reflect mostly single
digit PoPs.

Going into the weekend, zonal flow is replaced with meridional flow
and moisture steadily creeps back into the area. An occluding
surface low should track from New England towards the Canadian
Maritimes as a strong cold front approaches our area. This stronger
front, along with an enhanced signal for large-scale forcing for
ascent, suggests that this period is worth watching for potential
weather impacts, but model differences lead to low predictability at
this time and we will continue to monitor. Therefore, capped PoPs at
20 percent for the end of the long term period owing to
uncertainty and lack of confidence.

Not much change is expected with temperatures. High temps forecast
to be in the low 80s with overnight low temps in the upper 60s to
low 70s.

Marine...
Brief favorable boating conditions today, but quickly deteriorating
behind a frontal passage on Tuesday with likely SCA required over
the Atlantic waters. Hazardous boating winds and seas will likely
continue through at the later part of the work week.

Beach Forecast...
With subsiding easterly flow today, expect low risk for rip currents
today over the Atlantic beaches. But the break will be short lived
as increasing fetch will again raise the risk for rip currents on
Tuesday and Wednesday, mainly for the Atlantic beaches.
&&

.Preliminary Point Temps/PoPs...
West Palm Beach  80  70  80  70 /  20  10   0   0
Fort Lauderdale  83  72  81  72 /  20  10  10  10
Miami            83  70  82  71 /  20  10  10  10
Naples           83  64  83  67 /  10   0   0   0

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&


Update...09/Bhatti
Marine...17/AR
Aviation...09/Bhatti
Beach Forecast...17/AR
Short Term...17/AR
Long Term...03/Fell



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