textproduct: Miami - South Florida

KEY MESSAGES

Updated at 750 AM EDT Mon Sep 14 2026

- Scattered showers and thunderstorms focus mainly across interior South Florida today with a few extending towards the coasts. Frequent lightning, heavy rain and gusty winds will be possible with any storms. - High temperatures will generally rise into the low to mid 90s across South FL each day, resulting in widespread Moderate HeatRisk.

SHORT TERM

(Today through Tuesday) Issued at 1255 AM EDT Mon Sep 14 2026

Mid-level ridging will remain draped over the peninsula to begin the week, keeping anomalously strong 500 mb heights and hot temperatures across most of the Deep South. The main high pressure center will be located right over the southern Appalachian mountains, with H5 heights climbing to a near record 597 to 600 dam for this time of year. Fortunately for us in South Florida, H5 heights will only be around 592 to 593 dam, only slightly above average. This will translate to another hot day across South Florida, with maximum temperatures in the upper 80s and lower 90s areawide for Monday and Tuesday. Widespread moderate HeatRisk will once again be likely across all urban areas, affecting sensitive individuals without proper cooling and hydration. Heat indices are expected to remain below Heat Advisory criteria, with only about a 30% chance of exceeding heat indices greater than 105 F.

With high pressure overhead, winds will be light and variable through most of the morning. Coastal sea breezes will then begin creeping inland through the early afternoon. Light to calm winds and clear skies overnight should allow for efficient nighttime cooling, so some guidance is hinting at the development of isolated to patchy fog during the early morning hours for portions of interior South Florida. Wet antecedent conditions should allow for some saturation to occur as temps drop into the low 70s. However, fog is not expected to be impactful and there is very low confidence for visibility dropping below 5 miles. The recent 00z MFL sounding and current SPC mesoanalysis data indicates that South Florida still remains under a pretty moist airmass, with PWATs between 2 and 2.3 inches. As a result, scattered thunderstorms are once again expected to develop along sea breeze and outflow boundary interactions through the afternoon. There is a signal for some increased concentrations of Saharan approaching the region on Monday, but most of it should stay to the south of the Florida Straits and over the Caribbean. Nevertheless, RAP model soundings are hinting at some increased mid-level dry air compared to the last few days, which may slightly hinder storm development during the afternoon. Don't expect much of a difference in storm activity this afternoon compared to yesterday, but PoPs are slightly lower, between 50% and 60%. Most activity should focus along interior South Florida, closer to the Gulf sea breeze. Frequent lighting, locally heavy rainfall, and gusty outflow winds will be the main threats. If a storm were to get strong enough, some of this mid-level dry air may contribute to a few 50 to 60 mph downbursts winds, as DCAPE will be near 1000 J/kg. But, confidence for this will be low, with thunderstorm gusts between 30 to 40 mph being more likely.

The forecast for Tuesday will be quite similar, with scattered storms across South Florida through the afternoon. One notable change that will begin on Tuesday is that pressure gradients along the Atlantic coast will tighten due to strengthening surface high pressure over New England. This will result in some slightly breezier easterlies on Tuesday afternoon. Therefore, most storm activity will focus along interior and southwest Florida, closer to the Gulf breeze. HREF ensemble guidance shows that a few hot spots of 2 to 3 inches of rain may occur across portions of mainland Monroe, Collier, and Hendry counties.

LONG TERM

(Tuesday night through Sunday) Issued at 1255 AM EDT Mon Sep 14 2026

A stout ridge will set up across the central US and the Eastern Seaboard towards the middle of this week. This will set up a Rex Block pattern with an upper-level low enhancing offshore in the western Atlantic and advecting southwestwards underneath the ridge towards the Florida Peninsula. With enhanced jet stream dynamics along the eastern side of the ridge, there is increasing confidence that this will cause the strengthening low pressure to eventually become cut-off by Thursday and Friday as it advects across Florida. The pressure gradient will strengthen quickly on Wednesday as the low approaches, with a breezier NE flow expected versus the lighter flow we have been experiencing lately. Forcing for ascent will increase via positive vorticity advection from the low between Wednesday and Friday, and with deep moisture (PWATs 1.7-2.0+ inches each day) remaining over the area through this time frame we can expect scattered to numerous showers and thunderstorms each day. Therefore, PoPs will be 70-80+% daily for the mid-to-late week period. The cut-off low is expected to be a cold core low, which could get interesting in terms of a severe threat as this typically results in steeper lapse rates. However, dry air wrapping into the system could lead to some capping and result in a more inhibitive profile for deeper convection. This will be something to monitor over the next several days.

Rain chances will continue to remain elevated for next weekend as well due to ongoing deep moisture presence. As the upper low departs into the Gulf later on Friday and into next weekend, low level flow will flip to east-southeasterly and likely shift the highest rain chances towards the interior and closer to the Gulf coast but rain chances will still be high across the entire region.

Overall, scattered to numerous showers and thunderstorms are expected each day through the period. As exact details become more clear, QPF confidence will increase which will allow for better assessment of any flooding potential. Other than that, no major hazards are currently expected other than the usual frequent lightning, strong wind gusts, and lower visibilities associated with stronger thunderstorm activity. High temperatures each day will be in the upper 80s to low 90s. Overnight lows will range from the low to mid 70s across SW Florida to the mid to upper 70s along the east coast metro.

AVIATION

(12Z TAFS) Issued at 750 AM EDT Mon Sep 14 2026

VFR conditions will prevail through the period. Light and variable winds should continue through the early morning hours. The Atlantic sea breeze will shift winds east for all eastern sites by midday, while a Gulf breeze will shift winds west at KAPF. Storm activity will focus over interior South Florida during the afternoon, but have included VCTS for all sites. Improving conditions overnight with light and variable winds.

MARINE

Issued at 1255 AM EDT Mon Sep 14 2026

With high pressure overhead, light and variable winds will prevail across most waters through the beginning of the week. Seas will generally remain below 3 feet through Tuesday across all marine areas, but isolated to scattered shower and storms may bring locally gusty winds and hazardous boating conditions. The weather pattern begins to change in the middle of the week, with increasing northeasterly winds areawide. This will allow for seas to climb into 5 to 8 ft range off the coast of Palm Beach, and 3 to 4 feet elsewhere on Wednesday. With winds also climbing into the 20 to 23 kt range, Small Craft Advisories may be needed. Chances for showers and storms will also increase areawide through the end of the week as a storm system looks to cross the region.

PRELIMINARY POINT TEMPS/POPS

Miami 90 79 90 80 / 40 10 50 50 West Kendall 89 77 90 77 / 50 10 50 30 Opa-Locka 90 79 90 78 / 40 10 50 50 Homestead 90 78 90 78 / 50 10 50 50 Fort Lauderdale 89 80 89 79 / 30 20 50 70 N Ft Lauderdale 90 80 90 80 / 30 20 60 70 Pembroke Pines 90 79 90 78 / 30 10 50 60 West Palm Beach 91 78 91 78 / 30 20 60 60 Boca Raton 90 79 90 80 / 30 20 60 70 Naples 91 76 92 76 / 50 30 80 20

MFL WATCHES/WARNINGS/ADVISORIES

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