textproduct: Miami - South Florida

KEY MESSAGES

Updated at 137 PM EDT Sat Jul 18 2026

- Heat indices will range between 100-105 degrees today. While below advisory thresholds, dehydration can occur. Therefore, make sure to stay aware of heat illness signs.

- Scattered showers and thunderstorms will develop today, favoring interior areas of South Florida in the afternoon.

SHORT TERM

(Rest of today through Sunday) Issued at 137 PM EDT Sat Jul 18 2026

Scattered showers and thunderstorms are currently ongoing across all counties in South Florida, with the bulk of the storm activity focusing along the Southwest coast in Collier County. This activity is associated with an amplified upper level-low pressure system currently spinning off of the Florida Gulf coast. Southerly flow is supplying increased moisture into the region and diffluent flow aloft is providing ascent and forcing for showers to blossom across the Gulf waters and much of southwest Florida. Several training thunderstorms have produced up to an estimated 4 to 6 inches along certain spots on the Collier County coast. As a result, the Weather Prediction Center has outlined a Marginal Risk (level 1 of 4) of Excessive Rainfall for the Southwest Florida coast, where locally heavy rainfall may produce urban flooding concerns for poor drainage and low lying areas. While more isolated in nature, the eastern metro areas have seen a a few training storms as well, but with less coverage and fast storm motions, rain amounts should not be impactful.

With the environment already being so worked over from morning convection, and widespread cloud cover keeping things on the cooler side, CAMs are hinting that most thunderstorm activity should start trending down by mid afternoon. A few breaks in the clouds could help destabilize the environment and steepen lapse rates, particularly over interior regions where there has been last storm activity this morning. This will likely allow for a few sea breeze induced thunderstorms to develop over the Everglades through the late afternoon. The center of the upper low pressure system will also begin to trend more northwestward over the next day, reducing coastal convergence and shifting the more favorable forcing and ascent more offshore. The corridor of deeper moisture will remain further west over the Gulf as well, with PWATs across South Florida expected to drop between today and tomorrow. Winds will shift from southwesterly to more southeasterly by Sunday, which will filter in a drier airmass from the Caribbean and perhaps even some increased concentrations of Saharan dust as well. This will lower PWATs to below average for this time of year. As a result, PoPs for this afternoon and tomorrow afternoon will generally be between 25 and 35% across most of South Florida, with higher chances of 40 to 50% for parts of Southwest Florida and near Lake Okeechobee. Gusty winds, frequent lighting, and locally heavy rainfall will be the main threats with any storm.

High temperatures today should be a tad less than the last few afternoons due to the increased showers and cloud cover. Sunnier conditions on Sunday should allow for highs to climb back up into the mid 90s. Overall, widespread Moderate HeatRisk will continue across the region, with locally Major HeatRisk for urban areas. Maximum heat indices will be between 100 and 105 F. These conditions will affect sensitive individuals without proper hydration and cooling.

LONG TERM

(Sunday night through Friday) Issued at 214 AM EDT Sat Jul 18 2026

The extended period heading into next week currently is expected to be a lengthy period that lacks any impactful synoptic features for South Florida. Surface high pressure over the western Atlantic will slowly attempt to expand back over the region, but otherwise the overall flow pattern will be extremely weak and the primary convective conductors will be diurnal heating and the afternoon sea breeze formation. Because of the weak flow aloft and near the surface, sea breezes will be able to advance inland each day and result in highest PoPs over inland/interior areas. The previously mentioned drier air mentioned in the short term discussion is projected currently to linger through mid-week as well, which is leading to rain chances being much lower than normal (15-30%) even on a typical summer day.

One feature that has been identified on the latest ensembles that is worth monitoring trends for over the next several days is a westward moving trough across the Caribbean late in the week. If this feature enhances or shifts in track at all, there would be potential for some increased rain late next week. Uncertainty is high, but we will be keeping an eye on it.

Otherwise, with the likely lower amount shower and thunderstorm coverage in the early and middle portions of next week, heat will be the highest impactful concern as temperatures are forecast in the mid to upper 90s each day. As a result, heat advisory potential will be assessed daily. It is advised to continue to limit strenuous outdoor activities and take action when you begin to experience symptoms of heat exhaustion or heat stroke. For more on what you can do to prepare for and mitigate heat illness, visit ready.gov/heat.

AVIATION

(18Z TAFS) Issued at 137 PM EDT Sat Jul 18 2026 With storm activity already diminishing, prevailing VFR conditions are expected through the period. However, have left in VCTS through the middle of the afternoon for all sites, with passing showers resulting in brief flight restrictions. Breezy southeast winds of 10 to 15 kts will persist through the early evening, before becoming light and variable overnight. KAPF could se a more south to southwesterly breeze.

MARINE

Issued at 214 AM EDT Sat Jul 18 2026

Moderate southerly to southeasterly winds are expected this weekend as an area of low pressure sits in the northeast Gulf. Scattered showers and thunderstorms will remain possible across all local waters through the weekend with higher chances for the Gulf waters. Seas across all local waters are expected at 2 feet or less. Brief periods of rough seas and gusty winds may accompany any thunderstorms over the waters.

PRELIMINARY POINT TEMPS/POPS

Miami 80 93 81 93 / 10 20 0 30 West Kendall 77 93 77 94 / 0 20 0 30 Opa-Locka 80 94 80 95 / 10 20 0 30 Homestead 80 93 80 93 / 0 10 0 20 Fort Lauderdale 81 92 81 93 / 20 20 0 20 N Ft Lauderdale 81 93 81 93 / 20 20 0 30 Pembroke Pines 81 95 81 95 / 10 20 0 30 West Palm Beach 79 93 79 94 / 20 30 10 40 Boca Raton 80 91 80 92 / 20 20 10 30 Naples 78 91 80 92 / 30 50 30 40

MFL WATCHES/WARNINGS/ADVISORIES

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