935
FXUS62 KMFL 101809
AFDMFL

Area Forecast Discussion
National Weather Service Miami FL
209 PM EDT Thu Sep 10 2026

...New UPDATE, AVIATION...

.KEY MESSAGES...
Updated at 208 PM EDT Thu Sep 10 2026

 - Numerous showers and thunderstorms are forecast today, focusing
   along the east coast this morning before the bulk of activity
   shifts over southwestern Florida this PM. Gusty winds and
   dangerous cloud to ground lightning is possible with any storm.

 - A moderate risk of rip currents is forecast at all east coast
   beaches of South Florida today.

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

&&

.UPDATE...
Issued at 208 PM EDT Thu Sep 10 2026

The forecast remains on track this afternoon, with wet and unsettled
conditions expected through the early evening hours. Early rounds of
showers and storms have already dropped about an inch of rain across
portions of the East Coast metro today, with some areas receiving 2-
3 inches where storms have clustered. The prevailing southeasterly
flow will continue to push convection towards the northwest, with
activity focusing over the interior and Gulf coast later this
afternoon. Chances for severe winds or hail remain very low given an
anomalously warm and very moistened atmospheric column; however,
frequent lightning, heavy rain and gusty winds up to 40 mph could be
possible with some of the stronger storms.

The pattern discussed in the previous Short Term discussion will
remain generally unchanged tomorrow as ridging dominates across the
region for the foreseeable future, and rinse and repeat
conditions will be expected across the entire area starting mid
morning onwards.

&&

.SHORT TERM...
(Today through Friday)
Issued at 124 AM EDT Thu Sep 10 2026

05z Mesoanalysis and wide lens visuals from GOES-19`s upper-level
water vapor imagery depict a continuation of pronounced mid to upper
level anticyclonic flow across most of the southeastern United
States this morning. While a combined southern and polar jet-stream
will continue to remain in a zonal orientation across the northern
half of the United States today, a transient lobe of longwave
troughing (already quite evident on GOES-19 mid/upper level imagery)
will accelerate eastward across the northern United States. The
arrival/injection of synoptic forcing across the eastern United
States will result in an acceleration and displacement of the
aforementioned upper-level ridge currently over the SE CONUS into
the western Atlantic waters by this afternoon. In response, 500mb
flow will veer slightly more southerly during this time frame which
may result in the greatest foci of convection across the Lake
Okeechobee region as well as inland southwestern Florida this
afternoon and evening. Before we head further down the atmospheric
column for the rest of our analysis, it is worth mentioning that
deterministic and ensemble guidance has come into better agreement
on the evolution of a mid to upper level impulse lifting northwards
across the region over the course of today. Guidance suggests that
periphery vorticity on the fringe of an upper level low far to our
south over the western Caribbean Sea will splinter off and slowly
lift north across the region today. As the impulse lifts northwards
over our area via general anticyclonic flow around the mid to upper
level ridge, 500mb temperatures over South Florida will cool
slightly to near or just below (-6C to -7C) the climatological mean,
steepen low to mid level lapse rates, and enhance convection just
enough for coverage to become more widespread in nature later today.
At the surface, an expansive ridge of surface high pressure across
the western Atlantic waters will remain in firm control of
prevailing background surface flow, keeping winds out of a gentle to
moderate southeasterly direction outside of any diurnal mesoscale
circulations. A short lived surge of "relatively" drier air observed
over the last several hours will give way to increasing low level
boundary moisture and higher PWATs for the remainder of today as a
plume of deep moisture associated with a weak surface trough (per
NHC/TAFB`s 00z surface analysis) moves into and across South
Florida. With the overall pattern for today covered, let`s break
down how things are forecast to play out.

The confluence of a land breeze and light easterly to southeasterly
flow over the nearshore Atlantic waters will once again set the
stage for another bout of morning shower and thunderstorm activity
across the instability laden Gulfstream waters over the next several
hours. With the aforementioned easterly wind component persisting,
scattered showers and thunderstorms may periodically move onshore
across coastal and metro portions of southeastern Florida for much
of the morning hours before an otherwise stable atmosphere onshore
results in the waning and dissipation of any convective activity
further inland. Diurnal heating and the erosion of a stout near
surface inversion (and any residual convective inhibition) will give
way to widespread cumulus development across most of the peninsula
during the late morning and early afternoon hours before
southeasterly background flow focuses the bulk of diurnal convective
activity across southwestern Florida and the Lake Okeechobee region.
Once again, ample instability (forecasted CAPE of 3000-4000+ J/kg)
and moisture will lead to scattered to numerous shower and
thunderstorms this afternoon and evening. However with the lack of
significant synoptic forcing, the threat of strong/severe convection
remains minimal as temperatures remain warm aloft and low to mid
level lapse rates remain rather lackluster and unassuming. The
classic low shear, high instability environment will support outflow
dominant multicellular clusters as convective cores congeal.
Frequent lightning, gusty sub-severe winds, and pockets of heavy
rainfall remains the primary hazard with showers and thunderstorms
today. HREF guidance once again suggests a reasonable worst case
solution of localized swaths of 2-3+" across the western half of the
peninsula this afternoon and evening which may result in some minor
localized flooding concerns if urban areas are directly impacted.
These isolated QPF maxima`s will mainly occur when convection is
pinned along boundary collisions. The greatest confidence for these
higher QPF values per the HREF/REFS is across inland southwestern
Florida along the confluence of the gulf breeze and outflow from
earlier convection to the east.

High temperatures are forecast to peak in the low to mid 90s across
most of South Florida this afternoon before convection (and
resultant cloud debris) act to cool temperatures down at impacted
locales. Before any relief from the heat, ample humidity and
sunshine will result in apparent temperatures reaching the 100F to
105F degree range across most of the region with peak apparent
temperature values closer to 106-107F across coastal southwestern
Florida. NWS`s Probabilistic HeatRisk has high probabilities (80-
100%) of Moderate HeatRisk across all urban areas of SoFlo and low
to moderate probabilities (20-40%) of Major HeatRisk across portions
of urban southeastern Florida today. Be sure to take necessary heat
precautions today if you or your loved ones are sensitive to heat.

Diurnal convection will once again wane in areal coverage after
sunset this evening with the loss of surface heating, resulting in a
lull in activity during the first half of tonight. A saturated low
level boundary layer, light southeasterly surface flow, and ample
instability offshore will once again support development of
nocturnal convection across the nearshore Atlantic waters and
immediate east coast of South Florida beginning during the early
morning hours of Friday. Aloft, the axis of mid to upper level
ridging over the western Atlantic waters will slide southwestward
and directly overhead of South Florida on Friday. 500mb temperatures
will remain near the climatological mean for this time of year with
overall convective threats remaining rather similar to what is
expected for today: dangerous cloud to ground lightning, heavy
rainfall, and gusty sub-severe winds. Continued southeasterly flow
across South Florida around the aforementioned surface ridge axis
over the western Atlantic waters will will keep the standard
easterly flow regime in place once again on Friday with convective
activity gradually propagating on a spatial and temporal scale from
east to west as the day progresses. The greatest QPF signal will
once again reside across inland southwestern Florida as the
convergence and ascent along the gulf breeze is maximized.

A rinse and repeat pattern is forecast on the temperature side of
the house on Friday as temperatures at daybreak will range from the
muggy low 80s along the immediate east coast to low 70s across
inland locales. Ample surface heating will result in peak afternoon
temperature values in the low to mid 90s once again. Apparent
temperatures (widespread 100F-105F) will remain below Heat Advisory
criteria but could still prove to be impactful given heat
sensitivity or prolonged outdoor exposure with no precautions.

&&

.LONG TERM...
(Friday night through Wednesday)
Issued at 124 AM EDT Thu Sep 10 2026

Both surface and upper-level weather patterns, minus some minor
tweaks on occasion, are forecast to remain rather static over the
upcoming weekend and into next week. The only major alteration that
we will be keeping a close eye on is the potential intrusion of
Saharan dust that could have some implications on our daily PoPs
should it come to fruition, but this will be discussed in further
detailed promptly. High pressure, for a start, will be a frequently
messaged term and repeatedly relayed over the next several days. In
the upper levels, a primary ridge axis centered over the subtropical
Atlantic this weekend will be displaced eastward. Our focus will
subsequently shift to a new centralized area of high pressure that
will be taking shape over the northeastern Gulf and later advance
towards the Southeast/Mid-Atlantic United States where it is
forecast to amplify quite notably during the upcoming work week.
ECMWF ensemble data suggests that 500-mb height anomalies could be
at the 99th percentile for climatology during the second half of the
weekend and into early next week across our peninsular waters when
the ridge will be in its earliest fortification phases and closest
vicinity to South Florida. As the aforementioned shift toward the
SE/Mid-Atlantic US occurs thereafter, the ridge will only continue
to strengthen with the ECMWF grand ensemble hinting at mean 500-mb
heights being at or near all-time records and enveloping maximum
climatological percentiles through midweek.

As for the implications this will have on South Florida, it will
help maintain a steady flow aloft primarily out of the east through
the weekend and into the following work week that will strictly
refrain us from being impacted from any frontal systems dropping
south from the higher latitudes but rather by occasional shortwave
impulses (which won`t be of much concern anyways) propagating from
east to west along the southern periphery of this abnormally
compelling anticyclonic feature. As mentioned in the beginning of
this discussion, there are signals amongst the models that a large
plume of Saharan dust will be riding our low-level easterlies from
the Greater Antilles through the Bahamas and potentially intruding
into South Florida late this weekend and into next week, but mainly
next week. Persistent subtropical ridging will be rambling back and
forth over the corresponding Atlantic waters through this entire
long-term period, helping to induce a resolute east to southeasterly
flow across South Florida this weekend and backing to more of a east
to northeasterly direction next week. Though long range model data
and NASA Dust Extinction Aerosol forecast products do show some
Saharan dust entering our atmospheric column next week, it appears
as if the forecast has remained consistent for the time being in
keeping the deepest concentrations to our south over the western
Caribbean Sea. National Blend of Models (NBM) reflects this, with
PWATs mostly remaining above 2" through the weekend (60-80th
percentiles as per climatology) but then dropping sharply come next
week with these same values being reduced to the 1.7-2.0" range.
This is also visualized in forecast soundings with drier air and
larger dew point depressions progressively becoming more evident
through Wednesday of next week.

With moisture content remaining above average through the weekend
and our predominant easterly surface flow in place, expect a fairly
typical summertime pattern to stay firm with showers and
thunderstorms developing over our local waters during each overnight
period at the expense of plentiful available instability (CAPE of
2000-3500 J/Kg as indicated by deterministic models) and the marine
diurnal max (DMAX) cycle occurring over and around the warm,
adjacent Gulf Stream waters. Expect these showers and storms to
gradually push onshore every morning and increase in coverage
thereafter as they go on to favor our downwind locations i.e. the
western half of South Florida during the afternoon and early evening
hours. Localized flooding will be a point of emphasis in and around
the Naples metro each afternoon this weekend and into early next
week amid fairly weak flow aloft (bulk shear mainly below 10 kts)
and the impending Gulf sea breeze counteracting our easterly surface
flow. It is not until the latter half of this long term forecast
(specifically Tuesday and Wednesday) that not only our background
flow starts to strengthen to a degree with the coinciding ridge
amplification across the SE/Mid-Atlantic US but also an increasing
easterly flow at the surface looks to offset the Gulf sea breeze
from pushing inland and thereby minimize the potential for slow-
moving storms/urban flooding. Both storm coverage and intensity are
still question marks going into next week, as the uncertainty
involving the magnitude/quantity of dry air/dust intrusion we could
possibly observe next week still very much exists. With our
prevailing easterly surface flow (and through much of the low to mid
levels for that matter), however, we should expect the highest
afternoon rain chances to favor the western half of South Florida
regardless. Given that rapid/robust storm upgrowth via moisture
gradients and downburst potential are typically hot topics of
conversation when discussing Saharan air intrusions, it is something
we will have to keep an eye on over the next several days and
specifically how the models evolve over time with respect to it.
Overall, we should remain in a rather fixed configuration in terms
of easterly flow and precipitation with QPFs showing the bullseye of
7-day rainfall totals over SW Florida, totally evident of a routine
summertime pattern here.

Typical South Florida heat through the upcoming weekend and into
next week, with highs consistently reaching the low to mid 90s each
afternoon and maximum apparent/feels-like temperatures in the 100-
105F range (with isolated higher values of 106-107F). Make sure to
take the proper precautions to protect yourself and those around you
from these elevated temperatures. Rip currents across our east coast
beaches will also be something to be cognizant of over the next 3-7
days with this persistent easterly flow (rip probs hovering around
25% through next week at our N Miami, FTL, and Juno Beach observing
stations, bordering a moderate designation).

&&

.AVIATION...
(18Z TAFS)
Issued at 208 PM EDT Thu Sep 10 2026

Periods of sub-VFR conditions will be likely this afternoon as
numerous SHRA/TSRA move from SE to NW across the CWA, so TEMPOs
remain in effect 18Z-21Z for most sites. Convection will start to
clear out after 22Z, with mostly calm clear skies forecast
overnight. SE flow prevails into the evening, with light and
variable winds overnight. SE flow and scattered to numerous showers
expected again tomorrow, with impacts to terminals likely.

&&

.MARINE...
Issued at 124 AM EDT Thu Sep 10 2026

Gentle to moderate southeasterly winds will prevail across the local
waters of South Florida for the remainder of the work week. The
exception to this will be a brief period each afternoon across the
nearshore Gulf waters as surface winds become more southerly in
direction due to the gulf sea breeze circulation. Scattered to
numerous showers and thunderstorms will develop over the local
waters both during the day and overnight periods. Gusty and erratic
winds, dangerous lightning, and sudden periods of rough seas, will
be possible in and around any thunderstorm activity. Wave heights
across the Atlantic waters will decrease to 2-3 feet by this
afternoon as northeasterly swell gradually subsides. Seas across the
nearshore Gulf waters will remain below 2 feet for the remainder of
the work week.

&&

.BEACHES...
Issued at 124 AM EDT Thu Sep 10 2026

The combination of northeasterly swell and onshore surface winds
will result in a moderate risk of rip currents at all east coast
beaches today. Many rip current fatalities occur on moderate days
as signage/communication of the threat of deadly rip currents is
not as amplified as high risk days. When in doubt, don`t venture
out.

&&

.PRELIMINARY POINT TEMPS/POPS...
Miami            81  90  79  90 /  20  60  30  70
West Kendall     79  90  78  90 /  20  60  20  80
Opa-Locka        79  91  81  91 /  20  60  30  70
Homestead        79  91  80  91 /  20  60  30  80
Fort Lauderdale  81  90  80  90 /  20  60  40  70
N Ft Lauderdale  81  91  81  91 /  20  60  40  70
Pembroke Pines   79  90  79  90 /  20  70  30  70
West Palm Beach  79  92  79  91 /  30  60  40  80
Boca Raton       80  90  79  90 /  20  60  40  70
Naples           76  91  77  91 /  40  70  30  80

&&

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

$$

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