textproduct: Miami - South Florida

KEY MESSAGES

Updated at 1258 PM EDT Wed Sep 30 2026

- Minor coastal flooding continues across all of South Florida during high tide cycles today. - Chances of showers and thunderstorms increase across South Florida today, with a medium chance (40-50%) mainly south of Alligator Alley.

SHORT TERM

(Today through Thursday) Issued at 325 AM EDT Wed Sep 30 2026

Satellite imagery and early morning analysis shows a somewhat transitional synoptic pattern in place across eastern US and the Gulf today. Aloft, a positively tilted trough over the Eastern Seaboard will gradually exit east through the day, while a mid-level impulse and associated pieces of relative vorticity will remain in place over the Gulf. Near the surface, high pressure will continue to build over the western Atlantic. This setup has promoted healthy moisture advection over the region the last 24 hours, while also producing widespread stratus cloud coverage across much of the Florida peninsula.

HREF guidance and deterministic high-res models suggest this setup could produce two rounds of showers and storms today: one in the early morning hours along the East Coast, and another round later this afternoon, with a line of showers moving south to north across the entire region. However, the persisting cloud coverage makes that forecast a bit tricky and low confidence. Despite the presence of the mid-level impulse, ample moisture and otherwise favorable parameters for convective development along the atmospheric column, the presence of abundant cloud cover could inhibit destabilization across the area and limit storm activity in favor of more stratiform, light-to-moderate rain throughout the day. Furthermore, the REFS stands on its own forecasting a more early-afternoon- focused strong-convective episode, which further complicates the forecast. For now, went with a generally middle-of-the-road approach that favors early morning showers along the East Coast, a secondary round of activity in the afternoon, but also 20-30% chances of precip throughout the day for the rest of the area. Additionally, knocked the chances for thunder down a hair from what the NBM came in with to account for the potential lack of strong convection.

High-res guidance shows that impulse becoming orphaned from the mean flow and weakening tonight into tomorrow as the parent trough moves east. Subsequently, mid-level ridging begins to build over the southeastern US tomorrow into Saturday, gradually pushing the weakened impulse further south and away from the area. The surface high will continue to build over the area, with continued moisture advection and easterly flow across the region. Guidance seems to continue supporting early morning showers and storms, with afternoon activity focused near Okeechobee. Overspreading cloud cover also continues to be favored, which would also complicate the forecast. Decided to go with a slightly more bullish forecast with slightly higher PoPs but otherwise a similar day to today is likely.

Cloud coverage could help moderate temperatures through the period, with highs in the mid 80s and lows in the low 70s.

LONG TERM

(Thursday night through Tuesday) Issued at 325 AM EDT Wed Sep 30 2026

A temporary return to the routine South Florida summertime pattern seems likely Friday onwards, as mid-level ridging and surface high maintain their influence across the area through the weekend. Easterly flow and continued moisture advection will result in afternoon convection developing along the East Coast, then drifting westward with the mean flow.

Conditions could transition back to a more wet and unsettled pattern once again early next week with the potential development of another trough over the eastern United States. This potential scenario could bring a cold front near the Florida peninsula sometime during the early half of next week. The timing and intensity of these features could determine when and where we get enhanced chances of rainfall. ensemble members from the global Canadian ensemble model suggest a deeper, more progressive trough, which would support enhanced rainfall chances early in the week. Meanwhile members from the European and American ensemble models show a slightly slower, potentially weaker system which would favor rainfall later in the week. For now, we left the generally bullish NBM forecast of 70-80% PoPs Monday and Tuesday untouched, but we will continue to monitor this forecast for any changes through the week.

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

(18Z TAFS) Issued at 1258 PM EDT Wed Sep 30 2026

Showers and storms expected to become more numerous over the coming hours however not enough confidence at any one site to upgrade VCTS to TEMPOs. Short-fuse amendments may be necessary for any sites that do end up directly impacted. Easterly flow and mainly overcast conditions continue through the period with vicinity showers or isolated thunderstorms lingering around the peninsula into the overnight and early morning hours. Significant uncertainty in periods of most impactful weather, however the signal is there for morning shower and thunderstorms near terminals on Thursday.

MARINE

Issued at 325 AM EDT Wed Sep 30 2026

Light to moderate easterly winds 10-15 kts will prevail across all local waters today, gradually increasing up to 15-20 kts on Wednesday as surface high builds over the western Atlantic. Seas should remain in the 1-3 feet range, and could gradually build into the 3-5 ft range tomorrow as winds surge. Isolated to scattered showers will develop each day, which may result in locally hazardous winds and seas.

BEACHES

Issued at 823 AM EDT Wed Sep 30 2026

Coastal flooding is forecast along the entirety of coastal South Florida during high tide cycles today. Observations continue to out-perform guidance, leading us to anticipate tidal gauges to reach Minor today. As such, a Coastal Flood Statement is in effect for southern Miami-Dade, Mainland Monroe, and coastal Collier through noon on Thursday. A Coastal Flood Statement also remains in effect for the Atlantic coastline through 5 PM on Thursday. Minor coastal flooding is possible within 1.5-2 hours of the peak of high tide.

PRELIMINARY POINT TEMPS/POPS

Miami 77 86 78 88 / 70 70 60 40 West Kendall 76 86 77 88 / 60 60 50 40 Opa-Locka 77 87 78 89 / 70 70 50 40 Homestead 77 87 78 89 / 60 70 60 50 Fort Lauderdale 77 87 78 88 / 70 70 60 40 N Ft Lauderdale 77 87 78 89 / 70 60 60 40 Pembroke Pines 76 86 77 88 / 70 70 60 40 West Palm Beach 77 87 78 89 / 60 60 50 50 Boca Raton 77 87 78 89 / 70 60 60 50 Naples 74 88 75 89 / 40 70 30 70

MFL WATCHES/WARNINGS/ADVISORIES

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