853
FXUS62 KMFL 041656
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
1256 PM EDT Thu Jul 4 2024

...New SHORT TERM, AVIATION, MARINE, BEACHES...

.UPDATE...
Issued at 952 AM EDT Thu Jul 4 2024

Yet another hot day is in store for South Florida. Heat indices
will likely rise into the 105-110 degree range this afternoon, and
could persist for several hours given the reduced rain chances -
especially across the east coast metro areas. With little change
to the pattern and conditions expected tomorrow, the Heat Advisory
was extended through Friday evening for the whole area. Peak heat
indices will likely reach the 105-110 degree range once again.
Other than this extension, no significant updates with this
forecast package. &&

.SHORT TERM...
(Today through Friday)
Issued at 253 AM EDT Thu Jul 4 2024

Modestly drier air (PWATs generally 1.6 to 1.8 inches) will filter into
the area today to the north of Hurricane Beryl`s circulation, while at
the mid-lvls the ridge over the SE CONUS will remain in place, with deep
(but not particularly strong) easterly flow prevailing. This configuration
should result in only isolated-scattered showers and storms over the east
coast metro with any activity likely shifted west by mid-late afternoon.
Storm coverage will be a bit more numerous over Interior and SW Florida
where low-lvl convergence will be maximized along the Gulf breeze, with
the peak storm time being late this afternoon into the early evening.
So it would likely be a good idea to keep an eye on the forecast/radar
if you have evening plans in SW Florida.

The main story today will be another day of excessive heat, with high
temperatures in the low to mid 90s and peak heat indices 105-110 degrees
expected area-wide (maybe even locally higher in Interior/SW Florida),
and consequently, a heat advisory is in place over all of South Florida.
Overnight lows will offer limited relief in the humid easterly regime,
with overnight lows struggling to make it out of the 80s near the coast,
and heat indices remaining above 90 degrees for much of the night.

The ridge will weaken and shift slightly east heading into Friday with the
synoptic low-lvl flow becoming lighter and more sea breeze driven.
Additionally, moisture will begin to pool once again over the area with
PWATs increasing back into the 2-2.2 inch range. Consequently expect
greater storm coverage relative to Thursday, with the focus largely
being near and just inland of the coasts along both sea breezes. Given
the increased moisture and lack of deep-layer steering flow,
localized hydro concerns will be possible with localized accumulations
in the 2-4 inch range. However, the weak forcing and lack of
shear should result in short individual cell lifespans, keeping the
hydro threat localized and low-end (i.e. more nuisance or poor drainage
flooding). Temperatures will only vary slightly from Thursday, likely a
little warmer on the east coast and a little cooler on the west coast, so
excessive heat will once again be a concern with headlines possible,
particularly if convection is slow to initiate.

&&

.SHORT TERM...
(Rest of today through Friday)
Issued at 1254 PM EDT Thu Jul 4 2024

A slightly drier air mass has arrived across South Florida evidenced
by slightly lower PWATs (1.6 inches) on our morning sounding. This
will help limit POPs for this afternoon, with partly cloudy to even
mostly sunny conditions expected to prevail for the remainder of the
holiday. Weak easterly flow persists as mid-level high pressure
remains across the Southeast CONUS. This could support a few showers
and storms across Southwest Florida this evening where convergence
is maximized along the Gulf Breeze. The main story today will be
another day of excessive heat, with high temperatures in the low to
mid 90s and peak heat indices 105-110 degrees expected area-wide
(maybe even locally higher in Interior/SW Florida), and
consequently, a heat advisory is in place over all of South Florida.
Overnight lows will offer limited relief in the humid easterly
regime, with overnight lows struggling to make it out of the 80s
near the coast, and heat indices remaining above 90 degrees for much
of the night.

The ridge will weaken and shift slightly east heading into Friday
with the synoptic low-lvl flow becoming lighter and more sea breeze
driven. Additionally, moisture will begin to pool once again over
the area with PWATs increasing back into the 2-2.2 inch range.
Consequently expect greater storm coverage relative to Thursday,
with the focus largely being near and just inland of the coasts
along both sea breezes. Given the increased moisture and lack of
deep-layer steering flow, localized hydro concerns will be possible
with localized accumulations in the 2-4 inch range. However, the
weak forcing and lack of shear should result in short individual
cell lifespans, keeping the hydro threat localized and low-end (i.e.
more nuisance or poor drainage flooding). Temperatures will only
vary slightly from Thursday, likely a little warmer on the east
coast and a little cooler on the west coast, so heat will once again
be a concern. Went ahead and extended the Heat Advisory through
Friday evening. Latest trends in the CAMs depict a potential late
start to convection on Friday with storms not beginning to fire
until around 3PM, which gives plenty of time for heat indices to
rise into the 105-110 degree range once again before cloud cover
saves the day. &&

.LONG TERM...
(Friday night through Wednesday)
Issued at 253 AM EDT Thu Jul 4 2024

Although the Southeastern US H5 ridge will continue to erode into the
upcoming weekend as troughing establishes itself over the SE US, and an
Atlantic cut-off low impinges on it from the east, at least for SFL its
general influence will remain, blocking the passage of any shortwaves and
cutting us off from the mid-latitudes. At the low-levels, generally light
S-SErly synoptic flow will become established beyond Saturday as South
Florida will come to reside on the western periphery of Atlantic high
pressure. The moist airmass, characterized by PWATs over 2 inches, will
remain in place through the upcoming weekend before some drier air/SAL
plume likely filters in from the southeast early next week.

Rain chances will remain seasonably high through the weekend, with
localized flooding being the main threat with any storms given the
continued weak flow and high PWATs. Somewhat reduced rain chances can be
expected early next week, however, it remains to be seen how quickly the
drier air arrives Monday and if it is able to persist through Wednesday.
With the ridge remaining in control, the only relief from the heat will be
daily storms/cloud cover, so highs in the 90s and triple-digit heat
indices are likely. Will have to monitor for heat headline concerns
more or less each day, with the driving factor on whether or not
advisories are issued likely being the timing and extent of precip
coverage.

&&

.AVIATION...
(18Z TAFS)
Issued at 1254 PM EDT Thu Jul 4 2024

VFR prevails at all terminals through the period. Scattered
showers and thunderstorms are possible around APF later this
afternoon. Light and variable flow overnight will become easterly
to southeasterly by the late morning hours. &&

.MARINE...
Issued at 1254 PM EDT Thu Jul 4 2024

Generally light easterly-southeasterly will prevail across local
waters through the end of the week as weak ridging prevails,
although winds could shift to the W-SW in the afternoons over the
near-shore Gulf waters as the Gulf breeze develops. Seas will remain
in the 1-3 ft range. Scattered showers and thunderstorms could
develop, resulting in locally higher winds and seas.
&&

.BEACHES...
Issued at 1254 PM EDT Thu Jul 4 2024

The moderate risk of rip currents will persist along the east coast
beaches today, as easterly flow persists. Winds will decrease Friday
into the weekend resulting in a decreasing risk of rip currents.
&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            79  93  79  92 /   0  60  20  50
West Kendall     77  94  77  92 /  10  60  20  50
Opa-Locka        79  94  79  92 /   0  60  20  50
Homestead        78  91  78  91 /  10  50  20  50
Fort Lauderdale  79  91  79  90 /   0  60  20  50
N Ft Lauderdale  79  92  80  92 /   0  60  20  50
Pembroke Pines   79  95  79  94 /   0  60  20  50
West Palm Beach  78  92  78  92 /   0  60  10  50
Boca Raton       78  93  79  92 /   0  60  20  50
Naples           80  92  80  92 /  60  80  20  60

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory until 8 PM EDT Friday for FLZ063-066>075-168-
     172>174.

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

$$

SHORT TERM...Rizzuto/Carr
LONG TERM....Carr
AVIATION...Rizzuto