564
FXUS62 KMFL 131716
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
116 PM EDT Sun Sep 13 2026

...New UPDATE, AVIATION...

.KEY MESSAGES...
Updated at 109 PM EDT Sun Sep 13 2026

 - Scattered showers and thunderstorms focus mainly across
   interior South Florida today with a few extending towards the
   coasts. Frequent lightning, heavy rain and gusty winds will be
   possible with any storms.

 - High temperatures will generally rise into the low to mid 90s
   across South FL each day, resulting in widespread Moderate to
   Major HeatRisk.

&&

.UPDATE...
Issued at 109 PM EDT Sun Sep 13 2026

Scattered convection developed early this afternoon across SW FL,
and an outflow boundary is racing towards the SE FL metro so
expect additional convection to spread eastward as the afternoon
progresses. Could be an isolated urban/poor drainage threat across
the east coast metro today, especially with the sea-breeze pinned
near the coast. Overall the previous forecast remains on track.
Only minor change made was to add some patchy fog over inland
south FL early Monday morning with light winds and clear skies
expected over the interior. Some of the hi-res models have picked
up on the fog potential as well.

&&

.SHORT TERM...
(Today through Monday)
Issued at 227 AM EDT Sun Sep 13 2026

A substantial ridge of high pressure remains parked across the south-
central and southeast U.S. that has resulted in many locations
across the Deep South reaching triple digits for ambient high
temperatures. Another feature of interest identified on latest
guidance is a tropical upper tropospheric trough (TUTT) located over
the Caribbean. This will be a feature to monitor into mid-week, but
is not expected to play an impactful role in the local weather at
least until mid-week. The high pressure over the Southeast states
will create a week flow pattern throughout the atmospheric column,
which should allow the afternoon sea breezes to advance inland and
collide over the interior regions of South Florida. Deep moisture
remains present across the area through the short term, so expect
afternoon showers and thunderstorms to increase in coverage with the
highest chances being for interior locations where the sea breezes
and other boundaries merge (70-80% PoPs). PoPs will still be
elevated closer to the coasts and metros as well, but will be in the
50-60% range and likely a result of initial convection as the
circulations develop and/or late day outflow boundary development.
Primary concerns will be frequent lightning, stronger wind gusts
below severe levels, and heavy downpours.

Total QPF is not expected to result in more than 0.5-1.5", but it is
worth mentioning that the HREF LPMM does show potential for highly
localized pockets to receive 5-7" of rain today. Therefore,
localized flooding cannot be ruled out but it is still highly
unlikely and the highest risk for this will be over the
Everglades. High temperatures generally remain in the upper 80s to
low 90s with overnight lows in the mid to upper 70s.

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 227 AM EDT Sun Sep 13 2026

Strong surface ridging will set up across the Eastern Seaboard
towards the middle of this week. Aloft, an even stronger ridge that
could be at or near all-time records with respect to 500-mb height
anomalies will be building over the eastern US. With this setup,
there is increasing confidence that jet stream dynamics will cause a
pronounced cut-off low to form off the mainstream flow of an upper-
level near eastern Canada. Guidance continues to hint at this trough
dropping southward underneath the potent ridge across the Eastern
Seaboard and approach South Florida mid-week around the Wednesday
night to Thursday time frame. This low also appears to "absorb"
the previous TUTT low over the Caribbean as it eventually advects
across the Florida Peninsula.

It remains too early to tell what exact impacts could occur from
this low advecting across the area late in the week, but in general
it will provide extra forcing for ascent that will be able to
produce widespread showers and thunderstorms under a deep moisture
presence (PWATs over 2.0"). As conditions evolve over the next few
days, details will become more clear and communicated. As of now, we
can expect numerous showers and thunderstorms each day with risks
for heavy rainfall resulting in flooding. High temperatures each day
will continue to be in the upper 80s to low 90s.

&&

.AVIATION...
(18Z TAFS)
Issued at 109 PM EDT Sun Sep 13 2026

Tricky wind direction forecast this afternoon with the east coast
sea-breeze struggling to push inland and outflow boundaries from
convection approaching the metro from the west. Have a brief
period of SE winds this afternoon at the terminals before winds
should switch back to a westerly direction by 20-21Z. Scattered
thunderstorms will result in brief flight restrictions and erratic
winds. Will amend if necessary.

&&

.MARINE...
Issued at 227 AM EDT Sun Sep 13 2026

A light to gentle and generally variable wind flow is expected
across the local waters today and into early this week. This flow
will eventually increase to near hazardous levels out of an easterly
to northeast direction as a disturbance approaches from the
northeast. Seas will remain 1-2 feet or less today and into early
this week. Scattered showers and storms remain likely each day,
primarily in the early morning and late night hours over the waters
and can result in locally hazardous winds and seas.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            77  90  79  90 /  10  50  10  70
West Kendall     75  90  76  89 /  20  50  10  70
Opa-Locka        78  90  78  90 /  10  50  10  70
Homestead        76  90  77  90 /  10  40  10  70
Fort Lauderdale  77  89  80  89 /  10  40  20  80
N Ft Lauderdale  78  90  80  90 /  10  40  20  80
Pembroke Pines   77  90  78  89 /  10  50  10  70
West Palm Beach  76  91  77  91 /  10  50  10  70
Boca Raton       77  90  79  89 /  10  40  20  80
Naples           77  91  76  92 /  20  70  40  80

&&

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

$$

SHORT TERM...Redman
LONG TERM....Redman
AVIATION...CMF