245
FXUS62 KMFL 210651
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
251 AM EDT Tue May 21 2024

...New SHORT TERM, LONG TERM, MARINE, BEACHES...

.SHORT TERM...
(Today through Wednesday)
Issued at 247 AM EDT Tue May 21 2024

Mesoanalysis this morning indicates a diffuse frontal boundary
oriented east to west across the area, best evident by a subtle
dew point gradient north to south across the region as well as a
wind shift to a northeasterly direction to the north of the
frontolytic boundary. Taking a peek aloft, a shortwave remains
just to the northeast of our region gradually shifting eastward
into the western Atlantic waters. 500mb flow on the posterior side
of this feature will usher in northwesterly mid-level flow across
the region today. The combination of stronger easterly/northeasterly
flow at the surface and north westerly flow aloft will act to
focus sea-breeze driven convection southward across the region,
with the greatest chances of precipitation across our southern
areas (particularly Miami-Dade County and Mainland Monroe) during
the afternoon hours. Storm evolution will once again be in the
form of multicellular clusters propagating along the edges of cold
pools, feeding off of ample CAPE profiles. Mesoscale models
indicate the potential of an SBCAPE gradient in conjunction with
the inward propagating Atlantic sea-breeze, enhanced ascent along
this boundary will lead to convective initiation during the
afternoon hours. Although overall severe parameters do not appear
to be conducive, there will still be the potential for an isolated
strong to severe storm or two. DCAPE values of 1000-1200+ J/kg
support the potential of wet microbursts with the strongest
convective updrafts. In addition, Although the axis of the
shortwave has propagated offshore of the CONUS, South Florida will
remain on the periphery of the cold pool aloft with 500mb
temperatures still in the -7C to -8C range. This could allow for
some small hail to fall if a taller core develops. In addition,
although antecedent conditions remain fairly dry across the
southern portions of the east coast metro area, cannot rule out
some pockets of minor urban flooding in vulnerable low lying
locations given the relatively light 500mb flow. High temperatures
will reach the upper 80s to low 90s across the region, with the
warmest temperatures being realized across southwestern Florida.

With the shortwave continuing to propagate to the east on Wednesday,
500mb flow will veer more to a northerly direction in nature. Combined
with northeasterly surface flow prevailing, sea-breeze circulations
will favor convective initiation across the southern inland portions
of our area. As the shortwave continues to propagate away, 500mb
temperatures will continue to warm with 500mb temps in the -5C to
-6C range possible. This will keep the majority of thunderstorm
activity in the garden variety form, although localized ascent
along boundary collisions could still support the potential of an
isolated strong to severe wet microburst if a storm pulses up and
collapses in a quick fashion.

&&

.LONG TERM...
(Wednesday night through Monday)
Issued at 247 AM EDT Tue May 21 2024

During the mid-week period, the mid-level shortwave will
remain situated over the western Atlantic waters to the east of
the Bahamas. A mid-level ridge will also develop and remain
centered over the western Gulf of Mexico during this time frame.
Between these two synoptic features, South Florida will remain in
a light northerly 500mb flow regime with a lack of synoptic
forcing across the area with the subtropical jet located well to
the north of our region. At the surface, ridging situated over the
southeastern United States will allow for relatively light winds
across the region. Therefore, with a lack of the aforementioned
synoptic support, mesoscale patterns, such as the sea-breeze
circulation, will dictate temperatures and the most probable
locations for convective initiation and coverage. Typical
thunderstorm hazards, such as heavy rainfall and gusty winds, will
be possible, but still cannot rule out isolated strong to severe
pulse storms that are able to take advantage of the localized
maximized ascent along boundary collisions even in the background
of a fairly benign pattern.

The mesoscale driven weather pattern will continue for much of the
long-term period as surface ridging remains firmly in place and
synoptic features remain to the north of South Florida. With the
advection of the surface ridge to the east, easterly surface flow
across the region will remain dominant. This will act to feature the
hottest temperatures across southwestern Florida for the time being as
the Atlantic sea-breeze is able to traverse further inland. High
temperatures will range from the upper 80s to low 90s across the east
coast of South Florida to temperatures in the low to mid 90s across
southwestern Florida. Although heat indices will be less oppressive
than the past couple of days, heat safety precautions should still be
followed, especially for vulnerable populations.

&&

.AVIATION...
(06Z TAFS)
Issued at 130 AM EDT Tue May 21 2024

Mainly VFR conditions will prevail through the overnight hours.
Light and variable winds overnight will increase out of the east
by early Tuesday afternoon to around 10 kts. Scattered showers and
storms will develop near the east coast terminals as Tuesday
afternoon progresses. Periods of MVFR or IFR will be possible in
and around storms. At KAPF, winds will increase out of the west in
the afternoon as a Gulf breeze develops.

&&

.MARINE...
Issued at 247 AM EDT Tue May 21 2024

Generally benign conditions should prevail across local waters
throughout the period. Locally enhanced winds and seas will be
possible in and around shower and thunderstorm activity across
our area waters.

&&

.BEACHES...
Issued at 247 AM EDT Tue May 21 2024

With onshore wind flow returning to the east coast of South
Florida, a gradual increase in rip current risks will materialize
across the east coast through the remainder of the work-week. A
moderate risk of rip currents is forecast for Palm Beach County
beaches today.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            91  76  90  76 /  50  30  50  20
West Kendall     91  74  89  73 /  50  30  50  30
Opa-Locka        91  77  90  76 /  50  20  50  20
Homestead        89  75  88  76 /  60  40  50  30
Fort Lauderdale  88  77  88  76 /  50  20  50  20
N Ft Lauderdale  89  76  88  76 /  40  20  40  20
Pembroke Pines   90  77  89  76 /  50  20  50  20
West Palm Beach  88  74  88  73 /  40  20  30  10
Boca Raton       88  76  87  75 /  40  20  40  20
Naples           90  74  91  75 /  20  10  30  20

&&

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

$$

SHORT TERM...Hadi
LONG TERM....Hadi
AVIATION...CWC