FXUS62 KMFL 181050 AFDMFL Area Forecast Discussion National Weather Service Miami FL 650 AM EDT Sat Jul 18 2026 ...New AVIATION... .KEY MESSAGES... Updated at 649 AM 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... (Today through Sunday) Issued at 214 AM EDT Sat Jul 18 2026 Current water vapor and IR imagery depict the amplified upper-level low in the northeastern Gulf that is continuing to produce a complex of showers and thunderstorms, along with a surface trough across the southeast states. The upper-level low will hang on the periphery of Southwest Florida today with potential for a few positive vorticity impulses to advect across South Florida and provide some extra forcing for ascent in addition to the sea breezes. This feature will then continue to advect slowly westward underneath a large ridge of high pressure over the Southwest U.S., and thus it's not expected to get any closer to our region than it is now. With the prevailing low- level and mid-level flow pattern being southerly to south- southeasterly, the Atlantic and Gulf breezes will be able to advance far enough inland that the brunt of convection today and on Sunday should focus over the interior regions and likely closer to Lake Okeechobee. Some isolated to scattered activity can still develop closer to the coasts early on in the day both days this weekend, but this activity is not expected to be very strong. Additional coastal shower and storm activity will be possible via outflow boundary development and collisions. On another note, while not as stout as earlier this past week we will still have a weaker Saharan Air Layer over the area that can inhibit convective growth via an influx of mid-level dry air. However, as we have seen before, this generally increases low level lapse rates which can result in a few deeper cores forming if peak diurnal heating can break through the 'cap'. Temperatures are expected to be a few degrees lower today than the last few, so this may limit the risk of a stronger storm or two forming but in general an isolated marginally severe storm via wind downbursts cannot be ruled out this weekend. Sunday has a higher chance of this due to temperatures rising back into the mid 90s, despite drier air causing PWATs to fall below 1.5" which would be below the 10th percentile for this time of year. With a slight decrease in temperatures today and some drier air influences that could result in slightly lower dew points, maximum heat index values are expected to be below advisory levels this weekend but they will still hover between 100-105 degrees. Therefore, precautions via hydration and cooling breaks are still highly advised as it can feel much hotter in direct sunlight. && .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-weekas 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... (12Z TAFS) Issued at 649 AM EDT Sat Jul 18 2026 Light and variable winds this morning with scattered thunderstorms across SW FL. Thunderstorms develop this afternoon across the east coast metro which may result in brief flight restrictions and erratic winds. Outside of convection, SE winds 10-15 kts this afternoon into early evening, with a westerly Gulf breeze at APF. && .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 91 80 93 81 / 20 10 20 0 West Kendall 92 77 93 77 / 20 0 20 0 Opa-Locka 93 80 94 80 / 20 10 20 0 Homestead 92 80 93 80 / 20 0 10 0 Fort Lauderdale 91 81 92 81 / 20 20 20 0 N Ft Lauderdale 91 81 93 81 / 20 20 20 0 Pembroke Pines 93 81 95 81 / 20 10 20 0 West Palm Beach 91 79 93 79 / 30 20 30 10 Boca Raton 90 80 91 80 / 30 20 20 10 Naples 90 78 91 80 / 70 30 50 30 && .MFL WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. GM...None. && $$ SHORT TERM...Redman LONG TERM....Redman AVIATION...CMF