640
FXUS62 KMFL 120705
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
305 AM EDT Wed Aug 12 2026

...New SYNOPSIS, SHORT TERM, LONG TERM, AVIATION, MARINE...

.KEY MESSAGES...
Updated at 200 AM EDT Wed Aug 12 2026

 - A Heat Advisory is in effect today for all of South Florida.

 - Heat remains the primary hazard through next week.

 - Highest rain chances today, Thursday, and Saturday.

&&

.SYNOPSIS...
Issued at 200 AM EDT Wed Aug 12 2026

Water vapor imagery this morning depicts several areas of enhanced
convection within the northern stream flow. These clusters of
storms were forced by weak shortwaves advecting around the
northern edge of southern CONUS ridging and along a frontal
boundary draped across the northern third of the country. As these
waves continue on a general NW to SE track, they`ll further
amplify the eastern CONUS trough as it moves into the western
Atlantic. This amplification will fracture the ridge that sprawls
the Gulf and SW Atlantic into distinct areas of high pressure over
the Gulf/Deep South and across the SW Atlantic. Global ensembles
generally agree on this synoptic evolution through Thursday.

Beyond Thursday we begin to look at shortwaves moving onto the
western US coast and another moving through Quebec. Global
ensembles have their greatest differences early in this window
when it comes to how far north/south to place the Canadian
shortwave, and later in the window with how the western CONUS
trough cuts off (or doesn`t) and how it eventually merges into the
northern stream. Between these two features lies a large and
anomalously strong ridge and the shape, movement, and positioning
of this ridge will depend a lot on the evolution of the
shortwaves. However, South Florida isn`t expected to be on the
edges of the ridge and instead firmly in its core, and thus the
forecast isn`t subject much to the current ensemble
disagreements.


&&

.SHORT TERM...
(Today through Thursday)
Issued at 200 AM EDT Wed Aug 12 2026

With the fracturing ridge comes the disruption of the easterly
steering flow as well as the continuity of the SAL. Today and
tomorrow will likely feature slightly higher PWATs than yesterday
and a very weak northerly steering flow. This will generally allow
for a little more thunderstorm development along the seabreezes,
little inland penetration, and a general southward movement of
storms along the seabreeze. Expect the highest rain chances,
though, to be across the southern half of South Florida where
outflow and storms pile up and move very little due to the weak
flow.

Even with the most anomalous part of the ridge over the Gulf and
Atlantic, column heights and temperatures are expected to still be
in at least the top quartile of climatology for this time of year.
This means we`ll be dealing with both warmer than usual
temperatures, and an increase in deep-layer moisture. Thus, a heat
advisory is in effect for today for all of south Florida and will
likely be needed for at least portions of south Florida again
tomorrow.

&&

.LONG TERM...
(Thursday night through Tuesday)
Issued at 200 AM EDT Wed Aug 12 2026

The extended period becomes a little tricky, not because of the
synoptic upper level pattern, but due to the timing of a wave of
tropical moisture between pockets of SAL. In general though,
global ensembles are within about 12 hours or so of each other
with the arrival of the brief period of enhanced tropical
moisture. What this ends up looking like is a day of more isolated
storm coverage on Friday with at least some SAL influence,
increased rain chances on Saturday, and then a prolonged period of
drier conditions Sunday into next week.

Regardless of rain chances, the deep layer ridging mentioned above
will become re-established and anomalously strong for this time of
year. Highs in the middle to upper 90s, with heat indices well
into Advisory levels are expected for much of the period.

&&

.AVIATION...
(06Z TAFS)
Issued at 200 AM EDT Wed Aug 12 2026

VFR will likely prevail at all terminals through the TAF. While
thunderstorm chances are higher than yesterday, storms are expected
to be scattered enough, and possibly inland enough, that
confidence is too low to include TEMPOs at this time. While
steering flow will be light and potentially northerly as an
average, low-level flow will likely be dictated by the seabreeze,
becoming onshore by the afternoon.

&&

.MARINE...
Issued at 200 AM EDT Wed Aug 12 2026

Light winds and low seas are expected through the week. Daily
wind increases to around 10 knots are expected in the seabreeze
zone, as well as a light chop. Shower and thunderstorm activity will
remain fairly isolated and mostly limited to the morning hours for
the east coast and the evening for the Gulf.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            93  79  92  81 /  40  10  30  10
West Kendall     93  75  92  77 /  50  10  40  10
Opa-Locka        94  80  93  81 /  40  10  40  10
Homestead        93  78  92  79 /  40  10  30  10
Fort Lauderdale  92  80  91  81 /  40  10  30  10
N Ft Lauderdale  93  79  92  80 /  40  10  40  10
Pembroke Pines   93  79  92  80 /  40  10  40   0
West Palm Beach  94  78  93  79 /  60  10  50   0
Boca Raton       92  78  91  80 /  50  10  40  10
Naples           91  78  92  79 /  40  10  50  20

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory from noon today to 7 PM EDT this evening for
     FLZ063-066>075-168-172>174.

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

$$

SHORT TERM...Harrigan
LONG TERM....Harrigan
AVIATION...Harrigan