textproduct: Key West

KEY MESSAGES

- Conditions remain somewhat favorable for an island cloud line and associated waterspouts this Sunday.

- Rain and thunder chances will gradually return to near normal by early to middle of next week.

- Highs in the lower 90s and dewpoints in the mid to upper 70s suggest afternoon heat indices will peak at 105 to 108 degrees.

DISCUSSION

Issued at 1010 PM EDT Sat Aug 22 2026 A col region within the surface wind field continued to linger over the Florida Keys this afternoon. Winds across the reef were light, occasionally variable, south to southeasterly breezes. In addition, CIMSS MIMIC Layer PWAT estimated values between 1.4 and 1.6 inches across the Keys throughout the day. For reference, the 10th percentile value at Key West for August 23 is around 1.5 inches. The KKEY 00Z sounding sampled an environmental PWAT that exactly matched the 10th percentile value. Measured low level winds were weaker than 5 knots. While the deep layers of the atmosphere were abnormally dry, that does not mean the surface dew points are lower than normal. Dew points in the mid to upper 70s were measured across the island chain throughout the evening. These features combined offer an explanation as to why the KBYX radar observed few, if any, showers developed near the Keys this evening. The most significant convection was a shower cell that managed to form just north of Big Pine Key just before sunset.

Tonight, there are very few indications the weather pattern will change significantly. The synoptic scale features that enabled the col region to form-a broad high over the western Gulf, the Atlantic High centered west of the Azores, and low pressure systems over North America-are still present. Expect another mostly clear and muggy night across the Keys. Winds may be even lighter than yesterday, so we have high confidence in radiational cooling reducing temperatures at the interiors of the largest islands. There are a few hints that we get a wetter pattern across the Keys in the numerical models, except that pulse of moisture was not arrive in the Keys until mid week. Tomorrow, brace for another day of muggy weather!

MARINE

Issued at 1010 PM EDT Sat Aug 22 2026 No watches, warnings, or advisories are in effect across the Florida Keys coastal waters.

From synopsis, a split ridge pattern remains in place across the Florida Keys coastal waters. This will promote generally light to gentle southeast to east breezes through Sunday night, becoming variable at times during the afternoon hours. While North Atlantic ridging builds westward, southeasterly to easterly breezes will become more established from Sunday night through the middle of next week, becoming gentle and at times moderate during the overnight hours.

AVIATION

(00Z TAFS) Issued at 1010 PM EDT Sat Aug 22 2026 VFR conditions will prevail at both EYW and MTH for the upcoming period. Periods of light and variable winds continue to be observed at both terminals. Showers are unlikely given the dry conditions. The greatest chance for VCSH would be tomorrow afternoon.

KEY WATCHES/WARNINGS/ADVISORIES

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