640
FXUS62 KMFL 191147
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
747 AM EDT Thu Sep 19 2024

...New AVIATION...

.SHORT TERM...
(Today through Friday)
Issued at 310 AM EDT Thu Sep 19 2024

Models remain fairly consistent in keeping a mid level trough/low
complex over the SE CONUS through at least today, keeping a
generally unsettled pattern across SoFlo. 00Z MFL sounding data
and model PWATs show values back to around 2 inches, with plenty
of atmospheric moisture available for localized heavy showers to
develop later today. Meanwhile, pressure gradients across the area
remain weak, with sfc winds generally light and variable at
times. Therefore, expect afternoon sea breeze and outflow
boundaries to again become focal points for deeper convection,
with potential for strong to locally damaging wind gusts with the
strongest thunderstorms. Highest POPs remain around 70 percent,
including most of the Atlantic coast metro areas. The weak storm
motion can significantly contribute to localized heavy downpours,
which could result in localized flooding.

For Friday, ensembles and global model solutions show fair
agreement in pushing a frontal boundary across the peninsula and
down to SoFlo later in the day. The front seems to become
stationary either over the southern tip of the state, or pushing
into the Florida Keys late Friday afternoon. Regardless, it should
bring an initial decrease in moisture, with POPs on a modest
downward trend heading into the weekend.

Temperatures are expected to again reach the upper 80s lower 90s
this afternoon and again on Friday, even with the lingering cloud
cover and rain activity, along with heat index values in the low-
mid 100s.

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 310 AM EDT Thu Sep 19 2024

Moving into the upcoming weekend, the upper level trough will
continue to dig southward into the southeastern CONUS. It will
maintain a W/NW flow over the region aloft as the trough`s backside
moves over Florida`s Peninsula. Meanwhile, the plume of moisture
remains over South Florida as the stationary front meanders across
the southern peninsula. Most convection will be driven by the sea
breezes and outflow boundaries, following the afternoon`s diurnal
heating and influence of widespread heavy PWATs (1.7-1.9"). The
primary hazards will be heavy rainfall, strong winds, and localized
flooding, especially over urban areas. While PWATs have dropped
below 2.0", with plentiful moisture and saturated grounds, any slow-
moving storms may lead to flash flooding.

As we move into Sunday and early next week, an expansive ridge will
stretch across the Gulf of Mexico and Florida as the trough moves
into the Atlantic. As this occurs, it will allow for drier air to
advect into the region. Currently, the extended models indicate a
chance for showers, with a drop in PoPs (30-50%) and lower PWATs
(1.4-1.7"), due to this incoming drier air mass. However, further
into the extended, less confidence in the regional impact from rain,
so PoPs are capped at 60% through day 7. This may allow for a drop
below climatological rainfall normals early next week. Looking into
the extended forecast, we will continue to monitor the tropics. In
the upcoming days, the area to watch will be in the western
Caribbean as there is potential for a body of low pressure to form.
The National Hurricane Center`s 2AM outlook has a 40% chance of
tropical formation in the next 7 days. As it remains far too early
for many upcoming details, we will continue to keep an eye on the
latest tropical forecasts.

Temperatures will be near seasonal normals throughout the long term
forecast. Afternoon high temperatures will be in the upper 80s to
low 90 and overnight lows in the 70s. With the potential for daytime
dew points to drop into the low to mid 70s, the drier air may
provide a relief from sticky humidity and heat advisories. However,
with less cloud coverage and lighter rainfall, it will still allow
for oppressive heat and warm temperatures.

&&

.AVIATION...
(12Z TAFS)
Issued at 746 AM EDT Thu Sep 19 2024

Mostly VFR conditions at the start of the period as light surface
winds prevail across the region. Later this afternoon, periods of
MVFR/IFR will be likely as slow-moving SHRA/TSRA develop and move
over all TAF sites. Conditions should begin to improve shortly
after sunset, but some stratiform rain coverage could linger into
the late night hours.

&&

.MARINE...
Issued at 310 AM EDT Thu Sep 19 2024

Winds remain generally light across the coastal waters today as a
weak surface boundary remains just to the north of the area, with
continuing scattered to numerous showers and thunderstorms
possible each day. The boundary reaches the area on Friday,
bringing a decrease in thunderstorm activity through the weekend
and into early next week. However, periods of locally higher seas
and gusty winds may accompany any thunderstorm that forms.

&&

.BEACHES...
Issued at 310 AM EDT Thu Sep 19 2024

Expect minor to moderate coastal flooding to continue during
periods of high tide. These elevated tides will continue to affect
all coastal areas of South Florida through Friday morning, for
which a coastal flood advisory remains in effect. For the upcoming
weekend, a decrease in northerly swell should help in decreasing
the potential for coastal flooding. However, an elevated risk of
rip currents could continue for the Palm Beaches during the next
several days.

NAPLES HIGH TIDE TIMES... 1:56 PM today.
LAKE WORTH HIGH TIDE TIMES...931 AM today, 949 PM tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            90  75  89  76 /  70  60  50  40
West Kendall     92  73  90  73 /  70  60  50  40
Opa-Locka        92  74  89  76 /  70  60  50  40
Homestead        90  74  89  76 /  70  60  50  40
Fort Lauderdale  90  75  88  76 /  70  60  50  40
N Ft Lauderdale  91  76  89  76 /  70  60  50  40
Pembroke Pines   92  75  91  76 /  70  60  50  40
West Palm Beach  92  75  89  76 /  60  50  40  30
Boca Raton       92  75  90  76 /  70  60  50  40
Naples           89  77  90  76 /  40  40  30  30

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 2 PM EDT Friday for FLZ069-075-168-
     172>174.

AM...None.
GM...None.
&&

$$

SHORT TERM...99
LONG TERM....JS
AVIATION...ATV