textproduct: Miami - South Florida

KEY MESSAGES

Updated at 652 PM EDT Sat Aug 15 2026 - Heat Advisory for all of South FL today. Temperatures will increase further Sunday through Tuesday, leading to increasing heat impacts.

- Stay tuned for further information on the developing heat episode, and be prepared to take precautionary/preventative actions in the coming days.

- A moderate risk of rip currents is expected today along the east coast beaches.

SHORT TERM

(Rest of today through Sunday) Issued at 240 PM EDT Sat Aug 15 2026

The tropical wave which moved through the area late last night has moved into the eastern Gulf, opening the door for surface high pressure to build into the area. At the synoptic scale, deep layered high pressure over the southern U.S. will extend across Florida and into the western Atlantic and be the dominant weather feature over our region through the weekend and the upcoming week.

This afternoon is the transition from higher moisture associated with the departing tropical wave, and drier air with the Saharan Air Layer (SAL) approaching from the Bahamas. GOES-derived Total Precipitable Water (TPW) product shows this quite well with a strong gradient this afternoon from 2-inch TPW values from Naples to Lake Okeechobee to 1.5 inches along the SE Florida coast. This pattern matches up well with forecast PoPs in the 40-60% range over the western half of the peninsula, and 20% or less over the eastern half. A few thunderstorms over the western half have the potential for stronger wind gusts. The aforementioned drier air over the Bahamas will move over South Florida tonight and Sunday, leading to PWAT values dropping to the 1.3-1.6 inch range. Those values are in the lowest 5% of climatology for this time of year. This will result in very limited convective development on Sunday, with perhaps one or two cells developing over the southern Everglades late in the afternoon.

The main weather story for this weekend (and beyond) is the heat. In addition to dry air, the SAL is also expected to bring unusually high temperatures in the 925mb-850mb layer, with the global model ensemble consensus showing temperatures at the highest climatological values on Sunday. Today's expected peak heat index values in the 105-110F range will likely increase by a few degrees on Sunday. Went with the NBM 75th percentile ("highest expected") max temperature on Sunday which appears to be verifying better than the median/50% value. This translates to mid-upper 90s for all but the immediate coastal locations. Most of South Florida, particularly the east and west coast metro regions, will be in solid Major HeatRisk (level 3 of 4) with a 20-30% chance of Extreme HeatRisk (level 4 of 4) across parts of inland and southern Collier County. Therefore, the streak of daily heat advisories will continue on Sunday, with even higher concern in the days to follow.

LONG TERM

(Sunday night through next Friday) Issued at 240 PM EDT Sat Aug 15 2026

The strong high pressure over the southern U.S. will consolidate over the lower Mississippi Valley and northern Gulf most of next week. This will result in a generally W-NW low/mid level wind flow across South Florida through at least Wednesday. In August, a northerly component to the wind usually means well above normal temperatures, and the upcoming work week is primed to be the hottest period so far this summer. The unseasonably high temperatures in the low levels will extend through the 700 mb level as the high pressure expands, and further increase our confidence in impactful heat. Continued to lean on the 75th percentile NBM max temperatures for Monday and Tuesday which yields upper 90s over most of South Florida, including east coast metro areas very close to the coast. We even have a few 100-degree spots in the forecast over the Everglades Monday and Tuesday, and one or two spots over the outlying suburbs could also reach 100F. Although some afternoon mixing of drier air to the surface may lower dewpoints to the lower 70s, heat index values are still expected to top out close to (if not exceed) 110F. The GFS ensemble probability of heat index above 110F in Miami is between 35-40% Tuesday and Wednesday. Therefore, not only are Heat Advisories an almost sure bet, but we'll have to consider Extreme Heat Warnings (110F or higher heat index in Miami-Dade/Broward and 113F or higher elsewhere) if trends continue. As expected, HeatRisk is showing 20-40% chances of Extreme (level 4 of 4) over parts of metro SE Florida. Only slight relief is possible for the end of the week, but still remaining above normal.

PWAT values are forecast to remain in the lowest 5% of climatology on Monday (1.3 to 1.6 inches), and slowly increase to around 1.7 to 1.9 inches Thursday and Friday. As a result, PoPs stay below August normals for most of the week, no higher than 20-30% each afternoon.

AVIATION

(00Z TAFS) Issued at 652 PM EDT Sat Aug 15 2026

A few SHRA/TSRA over the interior peninsula will dissipate by 02z, with VFR conditions prevailing. Drier airmass will move in through the rest of the forecast period with little to no SHRA/TSRA development in the second half of the forecast period. Sea/land breeze dominated winds to continue, with onshore wind peaking at 10-12 knots after 16z at all terminals.

MARINE

Issued at 101 AM EDT Sat Aug 15 2026

Gentle to moderate southeasterly breeze is expected today across the Atlantic waters, with gentle westerly winds for the Gulf waters. Seas will be 2 ft or less. A few thunderstorms are possible over the area waters today which may result in locally hazardous winds and seas.

BEACHES

Issued at 101 AM EDT Sat Aug 15 2026

Moderate east to southeast flow will result in an elevated risk of rip currents today for the Atlantic beaches. The rip threat is expected to decrease on Sunday.

FIRE WEATHER

Issued at 240 PM EDT Sat Aug 15 2026

Although relative humidity values will remain above critical values, the hotter temperatures forecast for Sunday through Wednesday will contribute to minimum relative humidity values around 40% over the Everglades and Big Cypress areas. The combination of high temperatures, limited forecast rainfall, and lingering drought will lead to enhanced fire weather conditions given the time of year.

PRELIMINARY POINT TEMPS/POPS

Miami 82 94 80 96 / 0 0 0 10 West Kendall 79 94 77 96 / 10 10 0 20 Opa-Locka 81 95 79 97 / 0 10 0 20 Homestead 80 94 78 95 / 10 10 0 10 Fort Lauderdale 81 93 79 95 / 0 0 0 10 N Ft Lauderdale 81 94 79 97 / 0 0 0 20 Pembroke Pines 81 94 79 96 / 0 10 0 20 West Palm Beach 79 96 78 98 / 0 0 0 20 Boca Raton 80 93 79 95 / 0 0 0 10 Naples 77 94 78 93 / 10 0 0 0

MFL WATCHES/WARNINGS/ADVISORIES

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