600
FXUS62 KMFL 032245
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
645 PM EDT Thu Sep 3 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 640 PM EDT Thu Sep 3 2026

 - An active weather pattern remains in place through the end of
   the week and into the upcoming weekend as scattered to numerous
   showers and thunderstorms will develop each day. The strongest
   storms could contain gusty winds and frequent lightning.

 - Heavy downpours with high rainfall rates combined with slow
   moving storms will continue to create the potential for
   localized flooding especially over the urban and poor drainage
   areas.

 - High temperatures will generally rise into the lower 90s across
   most of South Florida through the end of the week and into the
   upcoming weekend.

&&

.SHORT TERM...
(Rest of today through Friday)
Issued at 335 PM EDT Thu Sep 3 2026

Mesoanalysis this afternoon indicates a rather humdrum convective
environment across South Florida with brief instances of sufficient
localized ascent, maximized primarily along collision
points/convergence of mesoscale boundaries. While several synoptic
features exist on the far periphery of our area (upper level ridge
axis across the southwestern Atlantic waters, upper level low just
to the north of the Yucatan), overall synoptic influence remains
rather meager directly overhead of South Florida. 500MB temperatures
(based on the 18z MFL upper air sounding and ACARS data) have warmed
to around -5C which is near the 90th percentile for today`s date.
Warmer air aloft has resulted in a continuation of lackluster low
and mid level lapse rates which will limit any rapid upward
convective development growth and the threat of seeing more robust
convective cores across our area. Upper level flow between the upper
level ridge axis well to our northeast and upper level low near the
Yucatan to the southwest remains out of an southeasterly direction
which has resulted in anvil debris being briskly carried off to the
northwest. Even with anvil blow off tempering diurnal heating across
the region, a classic high instability, low shear environment
remains in play across South Florida this afternoon and evening.
Ongoing scattered showers and storms are likely to congeal into
outflow dominant multicellular clusters that propagate along
sprawling boundaries. While the 18z upper air sounding from MFL and
RAP mesoanalysis shows some residual dry air in the vertical column,
meager low level lapse rates will prevent any threat of strong to
marginally severe wind gusts with multicellular clusters today. In
this type of weather regime, the main concern for impacts will be
frequent lightning activity and heavy rainfall. Where pinned
boundary collisions occur, convection may persist slightly longer
which could result in pockets of 2-3" of rainfall in a short period
of time. The HREF and REFS both depict a corridor of higher QPF
across inland southeastern Florida over the next several hours,
primarily focused just inland of the east coast metro. Model
guidance can be fickle in the exact placement of these higher
pockets of QPF, so some potential remains for east coast metro areas
to see heavy rainfall and pockets of localized flooding, although
the threat will remain fairly marginal in nature. Overnight
convective activity is forecast to favor the nearshore waters of
South Florida as a land breeze and greater instability provide the
best dynamics there.

A slight enhancement of background southeasterly surface flow on
Friday will result in the foci of activity shifting westward across
interior southwestern Florida on Friday afternoon. Once again,
overall convective parameters will be fairly run of the mill for
this time of year with the main threat with convective activity once
again being lightning and pockets of heavy rainfall. Forecast model
soundings depict 500mb temperatures in the -5C to -6C range and
meager low and mid level lapse rates on Friday which will keep
diurnal convection fairly benign in nature. The HREF and REFS once
again depict a corridor of higher QPF (2-3"), shifted further west
across inland southeastern Florida. Given ongoing dry antecedent
conditions, this rainfall will help to continue to alleviate the
moderate to severe drought across most of inland South Florida at
this time. High temperatures outside of shower and thunderstorm
activity (and any resultant cloud cover), will reach the low to mid
90s across the region on Friday afternoon.

&&

.LONG TERM...
(Friday night through next Wednesday)
Issued at 335 PM EDT Thu Sep 3 2026

Model guidance is fairly consistent that moisture levels will remain
elevated and above climatological norms with PWATs staying above 2"
across South Florida going into the upcoming holiday weekend and
into early next week. The subtropical surface ridge axis located
just offshore of the Mid-Atlantic United States will continue to be
displaced to the southeast into the open southwest Atlantic waters
as we head into Friday and the weekend. Meanwhile in the upper
levels, an expansive ridge that had been dominating the eastern
section of the United States and keeping any and all significant
weather features well to our north will finally start to erode.
Looking further north, a large upper trough located over Atlantic
Canada/New England will swing south and eastward during the latter
part of the weekend and into early next week. An associated surface
low pressure system and cold front will respond accordingly by
dropping into the southeastern United States and becoming quasi-
stationary thereafter over the Florida peninsula. At the same time,
associated shortwave troughing will also look to drop southward in
tandem with our surface cold front on the southwestern flank of the
aforementioned upper trough, though the orientation of this vort max
and the most robust dynamics will remain to the north of South
Florida.

ALl in all, the presence of enhanced moisture will keep scattered to
numerous showers and thunderstorms in the forecast through Labor Day
weekend and into the early part of next week. Our subtropical ridge,
as it undergoes a slight westward expansion, will help induce a more
established southeasterly flow through the first half of the
weekend, thus allowing daytime convection to primarily favor the
interior portions of South Florida as the Gulf sea breeze also pushes
inland each afternoon. We will look to lose the influence of our
subtropical ridge during the second half of the weekend and into the
Labor Day holiday as we see it retreat into the southwest Atlantic
and be gradually replaced by a southward-advancing cold front. As a
result, we will notice a wind shift from southeasterly to more
southwesterly across much of the peninsula, leading to favored
shower and thunderstorm chances across our eastern metros. As with
any pattern that has convection pinned to the east coast, localized
flooding will be a legitimate concern in low-lying/poor drainage
areas. The overall severe threat will be low throughout this long-
term period as we expect mid-level temperatures to remain warmer
than average (falling within the 50th and 90th percentiles), shear
to stay relatively light, and no significant dry air intrusions to
promote microburst potential. The cold front, which will stay draped
north of our region, will slowly dissipate after Labor Day through
mid-week, allowing high pressure to build behind it and thus
reintroducing an easterly flow regime to the peninsula. In addition
to the heavy rainfall threat, cloud-to-ground lightning will perhaps
be our most pressing convective hazard this weekend with many of us
likely spending extended periods of time outdoors in our
festivities. Always remember, when thunder roars, go indoors. Remain
sheltered for at least 30 min after you have heard the last clap of
thunder. Highs are forecast to remain in the low to mid 90s with
maximum apparent temperatures reaching the 100-105 degree range each
afternoon preceding the initiation of daily convection.
Widespread moderate to locally major HeatRisk is expected to
govern both of our coastal metros.

&&

.AVIATION...
(00Z TAFS)
Issued at 640 PM EDT Thu Sep 3 2026

L/V winds are forecast overnight at all terminals with a
continued decrease of SHRA/TSRA in the near term, remaining away
from terminals. Between 06-12z, SHRA/TSRA may increase in
coverage across the nearshore waters along both the Atlantic and
Gulf coast. Confidence remains low for any impacts to terminals
during this time frame but have maintained the previous timing of
VCSH/VCTS at this time. SErly at east coast terminals and SWrly
flow at KAPF will kick in between 15-17z on Friday with increasing
SHRA/TSRA.

&&

.MARINE...
Issued at 455 PM EDT Thu Sep 3 2026

Light southerly winds will prevail across the nearshore waters
through the remainder of the week into the upcoming weekend. Seas
across the Atlantic and Gulf waters will remain at 2 feet or less
through the end of the work week. Scattered to numerous showers
and thunderstorms are forecast to develop each day through the
rest of the week into the upcoming weekend. Gusty and erratic
winds, elevated waves, as well as the occasional waterspout will
be possible in and around thunderstorm activity.

&&

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

&&

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

$$

SHORT TERM...Hadi
LONG TERM....AD
AVIATION...Hadi