textproduct: Miami - South Florida

KEY MESSAGES

Updated at 655 PM EDT Sat Jul 4 2026

- Scattered to numerous thunderstorms are ongoing and will persist until sunset. Frequent lighting, heavy downpours, and isolated wind gusts to 45 mph are the primary threats.

- Heavy downpours could lead to localized flooding through this evening, especially urban and poor drainage areas.

- Heat Advisory remains in effect for metro Miami-Dade, Broward, and Palm Beach Counties through 8 PM this evening. Peak heat index values will range from around 105 to 110 F. Wear light- weight, light color clothing and stay hydrated.

- There is a Medium (50 percent) chance of advisory-level heat for metro Miami-Dade, Broward and Palm Beach Counties on Sunday and Monday. Heat continues to build on Tuesday and Wednesday.

SHORT TERM

(Rest of today through Sunday) Issued at 139 PM EDT Sat Jul 4 2026

Numerous showers and thunderstorms were developing this afternoon within mean (0-3 km) Southerly flow around 5 kts in an air mass characterized by Perceptible Water up to 2.1 inches per satellite derived estimates. As of 3 PM, the majority of the shower and thunderstorm activity has shifted to interior South Florida where mesoanalysis shows the deepest moist convergence as the Gulf and Atlantic seabreezes interact. While east coast metro areas are overworked from earlier activity, SB CAPE around 4k J/kg as well as numerous outflow boundaries will likely reignite activity over the next couple of hours. DCAPE is increasing, with latest MIA ACARS sounding indicating around 800 J/kg, and mesoanalysis also shows similar values over Broward and Miami-Dade Counties. While the main concern with thunderstorms is wind gusts to 45 mph, cannot rule out an isolated gust to 55 mph mainly in the Southeast coastal metro areas. Given the aforementioned Precipitable Water values are over the 90th percentile per SPC Sounding Climatology, combined with easterly storm motions only around 5 to 10 kts, and some storms may lead to localized flooding through this evening, especially urban and poor drainage areas. The storms and their associated lightning threat will diminish around sunset.

Turning our attention to the heat as of 3 PM, many of the mesonet sites in the metro Miami-Dade, Broward, and Palm Beach Counties that have not been cooled by earlier/ongoing convection show heat index values around 105-108F. The heat advisory will remain in effect through 8 PM this evening.

On Sunday, Precipitable Water is modeled around 1.9 inches, near the 75th percentile per SPC Sounding Climatology, which is drier compared to Saturday. The low-level flow will be more Southeast, which should preclude the earlier start to convection across the east coast metro areas. While the mean (0-3 km) flow will be out of the Southeast around 5 to 10 kts, similar to Saturday, expect less shower/storm coverage due to the drier air aloft. Convective development will favor interior and Southwest FL coastal areas with seabreeze/outflow boundaries as primary forcing mechanisms. Mid-level lapse rates are modeled steeper compared to Saturday around 6.5 C/km and DCAPE may approach 800 J/kg across much of the area. In addition to frequent lighting and heavy downpours, isolated thunderstorm wind gusts to 55 mph are the main threats.

The heat will again be a concern on Sunday. There is a Medium (50 percent) chance of advisory-level heat for metro Miami-Dade, Broward and Palm Beach Counties from late morning through the early evening. While convection is expected to start later and highs will be similar to Saturday, the key will be dew points which may be a degree or two lower. Peak heat index values will range from around 105 to 108 F.

LONG TERM

(Sunday night through next Friday) Issued at 139 PM EDT Sat Jul 4 2026

Monday will feature a similar pattern to Sunday, although with a greater coverage of showers and storms is possible. This will influence the extent of heat indices, with a Medium (50 percent) chance of advisory-level heat for metro Miami-Dade, Broward and Palm Beach Counties. For Tuesday through Friday, South Florida will be increasingly under the influence of the western extension of the subtropical ridge. This introduces some uncertainty into the precipitation forecast. If Southeast low to mid-level flow is maintained, then precip chances would be higher, compared to lower with Southwest low to mid-level flow.

AVIATION

(00Z TAFS) Issued at 655 PM EDT Sat Jul 4 2026

VCTS will continue at much of the east coast metro terminals until around 01Z, followed by lingering SCT025 cigs overnight at all of the terminals. Another round of TSRA are expected on Sunday with the Atlantic and Gulf seabreezes moving inland during the afternoon and evening. Have included VCTS by 18Z followed by PROB30 groups. Brief restrictions to MVFR are possible with TSRA along with wind gusts around 25 kts. Activity should end by 01Z Monday at MIA and FLL.

MARINE

Issued at 139 PM EDT Sat Jul 4 2026

The coastal waters will be under the influence of the western extension of the Atlantic subtropical ridge over the next several days. Tonight through Monday, light to gentle breezes will favor a Southeast direction over the Atlantic waters and a Southwest direction over the Gulf waters, although becoming more onshore within the seabreeze zone from late morning into the evening hours. From Tuesday through Thursday, the ridge axis may shift north of the waters, which would introduce moderate Southeast breezes. Over the next several days, showers and thunderstorms will favor the open Atlantic and Gulf waters from late night into the morning, then developing over inland areas by the afternoon into the evening, although some of these could move out over the waters. The main concern will be briefly higher winds and seas in the vicinity of any thunderstorms and their associated outflow boundaries. Looking ahead, the overall coverage of showers and storms should decrease by Tuesday and Wednesday.

PRELIMINARY POINT TEMPS/POPS

Miami 79 91 79 92 / 20 60 20 80 West Kendall 75 91 76 92 / 20 60 20 80 Opa-Locka 78 92 79 93 / 20 60 30 80 Homestead 79 91 79 92 / 20 50 20 70 Fort Lauderdale 79 90 80 91 / 20 50 30 80 N Ft Lauderdale 79 90 79 91 / 20 60 30 80 Pembroke Pines 80 93 80 94 / 20 60 30 80 West Palm Beach 78 91 78 91 / 30 60 20 80 Boca Raton 79 90 79 91 / 20 60 20 80 Naples 78 90 78 92 / 60 40 40 50

MFL WATCHES/WARNINGS/ADVISORIES

FL...Heat Advisory until 8 PM EDT this evening for FLZ068-072-074-168- 172-173.

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