039
FXUS62 KMFL 211358
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
958 AM EDT Fri Jun 21 2024

...New UPDATE...

.UPDATE...
Issued at 943 AM EDT Fri Jun 21 2024

Plenty of moisture remains in place this morning across South
Florida as PWAT values from the KMFL 12Z sounding came in at 2.09
inches. There is a pocket drier air that is trying to push in
from the northeast and that can been seen really well on water
vapor satellite imagery this morning. This drier air will help to
limit convection chances heading into this afternoon and this
evening. While there will still be enough lower level moisture in
place to support scattered shower and thunderstorm development
along the sea breezes, the chances for strong thunderstorm
development will remain limited due to the drier air pushing into
the mid levels. With the east to southeasterly wind flow in place,
the highest chances of thunderstorm development will remain over
the interior and west coast where sea breeze boundaries will
interact with each other as they push inland. High temperatures
this afternoon will rise to around 90 along the east coast, and
into the lower to mid 90s across Southwest Florida. Heat index
values will be even higher and they will generally range between
100 and 105 across most areas this afternoon.

&&

.SHORT TERM...
(Today through Saturday)
Issued at 229 AM EDT Fri Jun 21 2024

Models bring a weak sfc trough closer to the SE Atl coast today,
which drags a large area of enhanced moisture into the region. The
latest National Hurricane Center forecast shows a 50 percent
chance of cyclone development in the next couple of days.
Therefore, the current forecast philosophy for the short term may
need adjustments as the situation evolves.

For now, the forecast calls for the bulk of the moisture
advection to remain further north of SoFlo this afternoon.
Meanwhile, GFS/EURO and ensembles show good agreement in showing a
pocket of drier air wrapping around the western edge of the
trough, and advecting it into the area. This synoptic setup should
result in lowering POPs, with most locations in the 30-40 percent
range. The drier air will also help in inhibiting vertical
development of thunderstorms. As the trough moves closer, the
ridge over the SE CONUS flattens some, with veering of winds
across SoFlo bringing a more SE flow this afternoon. Thus, expect
the best chances for scattered showers and storms around the Lake
region, especially with the east coast sea breeze pushing inland.

For Saturday, the overall weather pattern continues but with
additional moisture filtering from the south. Latest model
soundings suggest PWATs increasing to 2.0-2.5 inches, which will
support scattered showers across much of SoFlo in the afternoon.
The prevailing ESE wind direction will again place best chances of
rain/storms over the Lake region and Gulf coast locations.
However, some initial convection may develop around the east coast
metro areas in the morning hours. Then in the afternoon, the sea
breeze boundaries will likely become foci for deeper convection.

Temperatures today and Saturday will warm up into the low 90s,
with heat index values in the low 100s, but not expected to reach
advisory criteria.

&&

.LONG TERM...
(Saturday night through Thursday)
Issued at 229 AM EDT Fri Jun 21 2024

Long range models show increasing rain chances for much of the
long term. A persisting southerly component in the low level flow
will keep deeper moisture moving across SoFlo, with PWATs of 2
inches or higher. POPs up to 60 percent each afternoon along with
sea breezes will result in scattered to numerous showers and
thunderstorms. Meanwhile, the dominant ridge centered around the
SE CONUS will weaken due to the influence of a trough/low complex
moving over the NE CONUS early in the week. This will result in
weakening pressure gradients and lighter sfc winds over SoFlo
below 10 mph. Therefore, any locations affected by slow-moving
heavy downpours could experience localized flooding.

With the lack of overall steering flow, outflow boundaries and
the sea breeze circulations will drive the deeper convection.
Thus, concerns about flooding will include any of the already
hard-hit metro areas during the latest round heavy rains.

Temperatures are expected to remain near normal values with
afternoon maximums in the upper 80s to mid 90s. Heat index values
will remain in the low 100s with prevailing warm and muggy
conditions each day.

&&

.AVIATION...
(12Z TAFS)
Issued at 732 AM EDT Fri Jun 21 2024

VFR conditions will prevail throughout the forecast period. Light
and variable winds will increase out of the ESE by the late
morning hours. Isolated to scattered showers may pass near the
east coast terminals during the late morning and early afternoon
hours, however, they should push towards the interior later this
afternoon. At KAPF, winds will shift to the WSW as a Gulf breeze
develops this afternoon. Scattered showers and storms are
possible near KAPF as well this afternoon.

&&

.MARINE...
Issued at 229 AM EDT Fri Jun 21 2024

Weakening E/SE winds will allow for seas to subside and remain
below SCA levels during the next several days. However, increasing
thunderstorm activity will result in brief periods of rough seas
and gusty winds, especially with the strongest storms.

&&

.BEACHES...
Issued at 229 AM EDT Fri Jun 21 2024

Easterly to southeasterly winds along the Atlantic coast will
keep the high risk of rip currents for all beaches today and
Saturday. Winds will then relax enough for the risk level to drop
to moderate levels from Sunday into early next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            90  80  90  80 /  20  40  50  40
West Kendall     91  79  91  77 /  20  40  50  40
Opa-Locka        91  80  91  79 /  20  40  50  40
Homestead        89  80  89  79 /  20  40  50  40
Fort Lauderdale  89  80  88  80 /  20  40  60  40
N Ft Lauderdale  90  80  89  80 /  20  40  60  40
Pembroke Pines   92  81  92  80 /  20  40  50  40
West Palm Beach  91  79  90  78 /  20  30  60  40
Boca Raton       91  80  90  80 /  20  40  60  40
Naples           92  78  92  77 /  40  50  60  50

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Saturday evening for FLZ168-172-
     173.

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

$$

SHORT TERM...AR
LONG TERM....AR
AVIATION/UPDATE...CWC