textproduct: Miami - South Florida

KEY MESSAGES

Updated at 126 PM EDT Wed May 20 2026

- High risk of rip currents along the east coast of South Florida will continue through this evening.

- Scattered showers and thunderstorms will develop mainly across SW Florida again today. Frequent lightning, gusty winds and locally heavy downpours are the main threats.

- Widespread Moderate HeatRisk for all urban areas through the end of the week. Heat indices in the upper 90s and lower 100s.

SHORT TERM

(Today through Thursday) Issued at 123 AM EDT Wed May 20 2026

The pattern will remain generally unchanged through the short term period, with an upper level ridge extending across the Gulf and over the peninsula and an upper level low meandering over the western Atlantic waters. Near the surface, an area of high pressure will remain in place over the western Atlantic waters, extending over the peninsula. This setup will help promote robust easterly flow across South Florida during this period, while also maintaining some moisture advection near the surface. However, overnight observations from the 00Z MFL sounding and ACARS flights at KMIA show a pocket of drier air intruding near the mid-levels. Water vapor imagery suggests this is dry air being pulled southward along the western periphery of the upper level low currently east of the Bahamas, and model guidance supports a continuation of this phenomenon at least through Thursday. In fact, most modeled PWATs within the ensemble guidance envelope are trending below average for this time of year, really highlighting the shift from conditions earlier in the week.

With prevailing easterly flow and some low-level moisture still in place, chances for showers and thunderstorms will remain on the forecast each day, especially along the sea breeze boundaries over interior/southwest FL each afternoon. However, with drier air aloft and weak forcing and steering, any activity that develops should be transient and sub-severe in nature, with occasional lightning and some gusty winds the main impacts. Some spots could get half an inch to an inch of rain, but otherwise the risk of localized flooding remains low at this time.

Temperatures each day will continue to rise into the upper 80s (along the East Coast) and up into the mid 90s (across southwest FL), with heat indices peaking in the mid 90s across the East Coast, and up into the triple digits across southwest FL. Warm overnight temperatures, especially across the East Coast, will impede much in the way of relief, especially for any vulnerable communities.

LONG TERM

(Thursday night through Tuesday) Issued at 156 AM EDT Wed May 20 2026

Upper level ridging will continue to dominate the weather pattern aloft across the southeast CONUS through the end of the week. The upper low over the western Atlantic will begin to dissolve and high pressure ridging over the Gulf will shift eastward over the Florida peninsula. Pressure heights will increase slightly across the region heading into next week, with a new H5 centroid positioning itself over north Florida by Sunday afternoon. Pressure heights will generally be in the 588 dm to 592 dm range through the period, which are within the upper quartile for this time of year. At the surface, high pressure over the western Atlantic will keep the easterly wind regime through the middle of next week. This pattern will continue to advect some waves of higher moisture, where PWATs may climb up to 1.8 inches. But for the most part, precipitable water content will generally remain about average at 1.4 to 1.5 inches. Models are not showing as clear cut of a middle dry layer, but ridging aloft should contribute to some mid-level subsidence and suppression of stronger storm activity. Overall, with easterly flow prevailing, the highest chances for afternoon storm activity will focus along the Gulf breeze over interior and southwest Florida each afternoon.

Temperatures will trend slightly higher for the weekend and towards the beginning of next week. Maximum temperatures will range from the upper 80s along the Atlantic coast to the mid 90s in southwest Florida. Heat indices will climb into the mid 100s for parts of Collier and Monroe counties. At this time, Heat Advisories look unlikely, but the NWS Prototype Probabilistic HeatRisk tool continues to show increased chances (40% to 50%) of Major HeatRisk. These conditions will affect anyone without proper hydration or cooling. Some guidance is also showing that overnight lows may stay quite warm across the east coast metros, with temperatures only dropping to upper 70s and low 80s.

AVIATION

(18Z TAFS) Issued at 126 PM EDT Wed May 20 2026

VFR conditions will prevail across the east coast terminals through the forecast period. ESE winds will range between 10 to 15 kts this afternoon into this evening. Winds could gust between 20 to 25 kts through the early evening hours. At KAPF, scattered showers and storms will be possible near the terminals this afternoon. Periods of MVFR or IFR will be possible around any shower or thunderstorm along with gusty and erratic winds.

MARINE

Issued at 123 AM EDT Wed May 20 2026

Generally benign boating conditions will prevail as alight to moderate easterly breeze persists across the local waters. Isolated to scattered showers will be possible each day, but will favor the Gulf waters under this easterly wind regime. Gustier winds and rough seas are possible in and around thunderstorm activity.

BEACHES

Issued at 123 AM EDT Wed May 20 2026

Strong onshore flow will continue to promote a high risk of rip currents across the Atlantic coastline through this evening.

PRELIMINARY POINT TEMPS/POPS

Miami 78 89 79 89 / 0 20 10 30 West Kendall 74 90 75 90 / 10 20 10 30 Opa-Locka 77 90 78 90 / 0 20 10 30 Homestead 77 89 78 89 / 10 20 10 20 Fort Lauderdale 78 87 79 87 / 10 20 10 20 N Ft Lauderdale 78 87 79 87 / 10 20 10 30 Pembroke Pines 78 91 79 91 / 0 20 10 30 West Palm Beach 78 87 79 88 / 10 20 10 20 Boca Raton 79 87 80 87 / 10 20 10 20 Naples 74 91 76 91 / 30 40 20 50

MFL WATCHES/WARNINGS/ADVISORIES

FL...High Rip Current Risk until 8 PM EDT this evening for FLZ168-172- 173.

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