textproduct: Miami - South Florida

KEY MESSAGES

Updated at 223 AM EDT Fri Sep 4 2026

- An active weather pattern remains in place through the upcoming holiday weekend as scattered to numerous showers and thunderstorms will develop each day. The strongest storms could contain heavy downpours 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 holiday weekend.

SHORT TERM

(Today through Saturday) Issued at 223 AM EDT Fri Sep 4 2026

A couple of mid level disturbances will gradually shift and move a bit further away from the region today. The first one will be a broad mid level low that will push into the northwestern Gulf, and then a weak mid level shortwave that will extend into Southern Georgia and Northern Florida. With these features being far enough away from the area, this will allow for 500mb temperatures to remain rather steady today between -5 and -6C. At the surface, high pressure centered in the western Atlantic will continue to extend over the Florida Peninsula and into the eastern Gulf as the day progresses. While the surface ridge axis will remain to the north of the region, there will be a slight enhancement of the synoptic southeasterly wind regime over the region. Plenty of moisture will remain in place through the atmospheric column as PWAT values will generally range between 2.1 and 2.4 inches today.

This abundance of moisture in place will once again support the development of scattered to numerous showers and thunderstorms as the sea breezes develop and push inland. With a slightly stronger southeasterly breeze today, shower and thunderstorm activity should gradually shift more towards the interior and Southwest Florida by mid to late afternoon. With the absences of mid level support, strong thunderstorm development will be rather limited and the main threats from convection will be heavy downpours as well as frequent lightning. The high moisture content in the atmosphere could lead to another day of enhanced rainfall rates which could lead to localized flooding, especially over areas that have seen recent heavy rainfall in the past several days. High temperatures today will rise into the lower 90s across most areas with peak heat index values generally ranging between 103 and 108.

Moving into the first part of the weekend, a deeper mid level trough will begin to dig southeastward across the Northeast and Mid Atlantic states, and then into the western Atlantic off of the Southeast coastline. This will generally leave South Florida in a weakness wedged between two mid level ridges, one building over the Plains, and another one pushing further eastward into the Atlantic. At the surface, high pressure in the Atlantic will gradually begin to shift southward as a weakening cold front pushes into the Southeastern portion of the country. This will allow for the synoptic wind flow to remain rather light and surface winds will remain sea breeze driven as Saturday progresses. Moisture content will remain rather high which will allow for another day of scattered to numerous showers and thunderstorms to develop. With lack of mid level support, chances for strong thunderstorm development will continue to remain very limited, however, the stronger storms will contain heavy downpours and frequent lightning. The potential for localized flooding will continue to remain in place due to the combination of slow storm motion and high rainfall rates. High temperatures on Saturday will rise into the lower 90s across most areas with peak heat index values ranging between 103 and 108.

LONG TERM

(Saturday night through Thursday) Issued at 223 AM EDT Fri Sep 4 2026

Heading into the second half of the weekend and into early next week the latest global and ensemble guidance suite remains in pretty good agreement with shifting the aforementioned mid level trough offshore, however, the mid level trough axis will remain near by just to the northeast of the region for Sunday into Monday. At the surface, the weakening cold front will eventually stall out over the Deep South and Northern Florida. This will allow for the synoptic wind flow to become more south southwesterly during this time frame. Deep tropical moisture advection will continue through Sunday and Monday as well and the mid level steering flow will remain light. With the best mid to upper level support remaining well off to the northeast of the region, convective initiation will remain sea breeze driven each day during this time frame, with the highest chances of showers and thunderstorms shifting over the interior and east coast metro areas during the afternoon and evening hours. Chances for strong thunderstorm development will remain rather limited, however, heavy downpours with high rainfall rates combined with slow storm motion will keep the potential for localized flooding in place especially across the urban and low lying areas. High temperatures for the second half of the weekend into early next week will generally rise into the lower to mid 90s.

Moving into the middle portion of the week, mid level troughing gradually begins to lift northeastward further away from the region and mid level ridging will slowly try to work back into the area. At the surface, the stalled frontal boundary to the north will gradually wash out as high pressure builds back into the region. This will allow for a return to a light easterly synoptic wind flow during this time frame across most areas. Leftover moisture from what is left of the old frontal boundary to the north will continue to pool over South Florida, especially on Tuesday. The latest guidance suite is hinting at moisture levels dropping a bit on Wednesday as the building mid level ridge increases subsidence across the region. With mid level heights slowly rising, and mid level temperatures slowly warming, strong thunderstorm development will remain very limited during this time frame and the main hazards with thunderstorms will be the potential for heavy downpours and frequent lightning each afternoon and evening. High temperatures on Tuesday and Wednesday will rise into the lower 90s across the east coast metro areas, and into the mid 90s across interior portions of Southwest Florida.

AVIATION

(06Z TAFS) Issued at 148 AM EDT Fri Sep 4 2026

Light and variable winds are forecast to persist overnight for all terminals, maintaining VFR conditions. Into the early morning Friday, offshore showers in the vicinity of all terminal sites will begin to develop. As a primarily S/SE flow sets up across SoFlo in the early afternoon, t-storm development will favor the interior. For APF, the Gulf breeze will shift winds to a primarily WSW flow in the early afternoon. Confidence remains low on direct shower/t-storm impacts to all terminals. As convection begins to diminish into the later evening, winds will return to light and variable overnight into Saturday.

MARINE

Issued at 223 AM EDT Fri Sep 4 2026

A gentle to moderate southeasterly breeze will continue across most of the local waters through the first half of the weekend. The exception to this will be across the Gulf waters, where they will become south southwesterly each afternoon during this time frame. Winds shift and become south southwesterly across all local waters heading into the second half of the weekend and into early next week. Seas across the Atlantic and Gulf waters will remain at 2 feet or less through the upcoming weekend. Scattered to numerous showers and thunderstorms will be possible each day through the weekend and into early next week.

PRELIMINARY POINT TEMPS/POPS

Miami 90 80 90 78 / 50 20 60 20 West Kendall 90 78 89 76 / 50 20 70 20 Opa-Locka 90 80 90 77 / 50 20 70 20 Homestead 91 79 90 77 / 60 30 60 20 Fort Lauderdale 89 80 89 79 / 60 30 60 20 N Ft Lauderdale 90 80 90 79 / 50 20 60 10 Pembroke Pines 89 79 90 78 / 50 20 60 20 West Palm Beach 91 79 91 77 / 40 20 70 10 Boca Raton 89 80 89 78 / 50 20 60 10 Naples 91 77 90 77 / 40 30 70 40

MFL WATCHES/WARNINGS/ADVISORIES

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