textproduct: Miami - South Florida

KEY MESSAGES

Updated at 935 AM EDT Tue Sep 29 2026

- Minor and moderate coastal flooding continues across southeast FL during high tide cycles today. Conditions gradually improve starting tonight. - Chances of showers and thunderstorms increase across South Florida today, with a medium chance (50-60%) mainly south of Alligator Alley.

UPDATE

Issued at 935 AM EDT Tue Sep 29 2026

After a respite from the humidity and showers/storms over the past several days, a return to the baseline is in the cards for South Florida today as we transition back to a wetter pattern. Looking at the mid/upper levels of the atmosphere, a stout mid to upper level trough is located across the southeastern United States which is actively enhancing divergence (and ongoing shower and storm activity) to our west over the Gulf. At the same time, cooler mid level air remains in place across South Florida with 500mb temperatures near the 5th percentile. A pronounced instability and moisture gradient is clearly present on 12z analysis across South Florida with ample convective inhibition still in place over most land areas (recent ACARS sounding from MIA shows this quite nicely) with the most favorable parameters for showers and storms in the short term confined south of Alligator Alley. Once again a bit of a challenging forecast with the advection of upper level cloud streaming over South Florida at the moment from ongoing activity in the Gulf, questions remain about just how much instability can materialize over land, as this cloud cover may suppress diurnal heating. The aforementioned diurnal heating and instability advection over the next several hours will be instrumental in determining how much convection we see later over land this afternoon and evening. While shear parameters remain meager, mesoscale models depict the potential development of a multicellular cluster across the southern portion of the peninsula this afternoon where instability and moisture may be maximized. If this does indeed occur (see above sentences for uncertainty complexities), there is a conditional risk of strong wind gusts and a non-zero chance of a brief tornado (potential interactions with the east coast sea- breeze). Mesoscale models often struggle with resolving this type of pattern, which appears to be the case once again with current radar spatial and temporal coverage much more active than what was previously depicted. GOES- East imagery shows a clearing across the Florida Keys which could lift northwards into the southern half of South Florida later this afternoon, which may prove to be favorable for the development of another round of PM convection later today, mainly south of Alligator Alley.

SHORT TERM

(Today through Wednesday) Issued at 259 AM EDT Tue Sep 29 2026

A gradual transition towards more wet and unsettled conditions begins today. A mid-level shortwave impulse will approach from the Gulf; as it does, southerly to southwesterly flow along the atmospheric column will usher a moisture-rich airmass over the area, with PWATs expected to rise back into the 1.8-2.0 inch range. SPC's mesoanalysis already shows this happening, with analyzed PWATs over the area up into the 1.6-1.8 inch range as of 06Z. Later today, the influence of this impulse and the increase in moisture across the area will allow for the return of scattered showers and thunderstorms across South Florida (with PoPs in the 50-60% range). While most of the activity looks like it stays south of our area, CAMs are still suggesting isolated to scattered activity beginning shortly after daybreak, starting across southwest FL and drifting eastward across the region.

The midlevel impulse will linger over the Gulf overnight and into Wednesday, continuing to promote unstable and humid conditions across South Florida. Coverage looks to be a bit more sparse throughout the day compared to today, but PoPs remain in the 50-60% range, supported by high-res ensemble guidance.

Increasing cloud coverage over the area will help keep high temperatures in the mid 80s today, while overnight lows will drop into the low to mid 70s. Warmer conditions are expected on Wednesday.

LONG TERM

(Wednesday night through Monday) Issued at 259 AM EDT Tue Sep 29 2026

Mid-level ridging will begin to build on Wednesday night as the mid- level impulse gets dragged northward with the mean flow. Near the surface, high pressure will continue to build across the western Atlantic into the weekend, bringing the return of easterly to southeasterly flow across the area. Moisture advection will continue, with PWATs forecast to continue hovering near 2 inches through the period. This pattern will promote continued scattered to widespread shower and thunderstorm development each afternoon. Storm activity will likely favor interior and southwestern Florida due to the stronger easterly flow during the latter half of the week. Conditions could become a bit windy as well towards the weekend as a frontal boundary settles across the southeastern US; its proximity to the surface high will help tighten up the pressure gradient across the region.

There is increasing confidence that temperatures will increase back into the upper 80s and low 90s areawide over the weekend, especially as easterly flow and moisture return increase.

AVIATION

(12Z TAFS) Issued at 726 AM EDT Tue Sep 29 2026

Light and variable winds will shift onshore after 16Z, increasing to 8-11 kts at all terminals. Isolated to scattered SHRA/TSRA are possible today, with the highest confidence for impacts at KAPF between 16-20Z. East coast terminals could see impacts between 21Z- 00Z, but confidence in the exact timing and coverage remains too low to include TEMPO/PROB30 groups at this time. Winds will become light and variable overnight at all terminals before increasing out of the east on Wednesday morning.

MARINE

Issued at 259 AM EDT Tue Sep 29 2026

Light southerly winds will prevail across all local waters today, gradually becoming more easterly on Wednesday as surface high builds over the western Atlantic. Seas should remain in the 1-3 feet range. Isolated to scattered showers will develop each day, which may result in locally hazardous winds and seas. Brisk conditions return late week.

BEACHES

Issued at 259 AM EDT Tue Sep 29 2026

Coastal flooding remains likely along the southeastern and southern coastlines during the high tide cycles today. Observations continue to out-perform guidance by a decent margin, leading us to anticipate tidal gauges to reach Moderate once again today. As such, A Coastal Flood Advisory remains in effect for the Atlantic coastline, while a Coastal Flood Advisory remains in effect for southern Miami-Dade and mainland Monroe, where Minor stage coastal flooding could be possible.

Conditions are forecast to begin improving this evening, but Minor flooding could still be possible tonight and tomorrow during high tide, so we went ahead and transitioned the Advisory to a Statement after 2PM today and extended it through tomorrow afternoon.

PRELIMINARY POINT TEMPS/POPS

Miami 86 75 87 77 / 70 50 60 70 West Kendall 85 75 86 76 / 70 40 60 60 Opa-Locka 86 75 87 76 / 70 40 60 70 Homestead 86 75 87 77 / 60 50 60 70 Fort Lauderdale 86 75 86 77 / 70 50 60 70 N Ft Lauderdale 86 75 87 77 / 70 40 60 70 Pembroke Pines 86 74 86 76 / 70 40 60 70 West Palm Beach 87 74 87 77 / 40 40 60 60 Boca Raton 86 74 87 76 / 50 40 60 70 Naples 85 72 87 73 / 60 40 60 50

MFL WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Advisory until 2 PM EDT this afternoon for FLZ168- 172-173.

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