246 FXUS62 KKEY 090231 AFDKEYArea Forecast Discussion National Weather Service Key West FL 1031 PM EDT Mon Sep 8 2025
...New DISCUSSION, MARINE, AVIATION...
.DISCUSSION... Issued at 1030 PM EDT Mon Sep 8 2025 It was a busy afternoon and evening across Miami`s coverage area with multiple advisories and warnings. While not nearly as busy as our neighbors to the north, KBYX radar detected shower activity the entire time with the first activity being across the offshore Gulf waters. Convection on the mainland moved southeastward which brought a surge of winds to the far Upper Keys, especially Ocean Reef area. Carysfort Reef Light recorded a wind gust of 29 knots or 34 mph around 700 pm earlier this evening. This storm that moved off the mainland did result in a Special Marine Warning being issued for the eastern Hawk Channel waters and the northeastern Straits. A few showers formed over the Lower Keys shortly after sunset resulting in a quick downpour from mainly Cudjoe Key to Big Pine Key. In the last hour or so, another outflow boundary moved off the mainland into Florida Bay resulting in the formation of more showers and thunderstorms. In addition, scattered showers have developed in the past hour across the southern Straits mainly south of the Woods Walls with additional shower activity now forming in the vicinity of Key West. Temperatures along the Island Chain are in the lower to mid 80s from the Middle Keys to Lower Keys with upper 70s for the Upper Keys. Dew points are in the mid to upper 70s. A similar pattern to recent days remains in place with weak low pressure over the east-central Gulf and weak high pressure across the Bahamas. This is resulting in marine platforms around the Keys observing south to southwest breezes of 5 to 10 knots.
.SHORT TERM FORECAST... The 00z evening sounding looks similar to recent evenings with a fairly saturated profile. The PWAT value measured remains quite high at 2.25 inches which is above the 90th percentile for the date. The wind profile shows southwesterly winds from the surface up to around 3000 ft AGL. Overall, we have the moisture, an outflow boundary moving southwestward through the Keys from off the south Florida mainland, and other residual boundaries throughout the Keys waters. Since we have basically all the ingredients to get shower and thunderstorm activity, no changes expected to the ongoing forecast.
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.MARINE... Issued at 1030 PM EDT Mon Sep 8 2025 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a surface trough will remain centered over the eastern Gulf and Florida Peninsula over the next couple of days. This trough will be slowly sheared out mid to late week. However, the pressure field in and around the Keys will generally remain poorly defined. Moisture will remain above normal. This along with the weak steering currents will result continued above normal convective potential.
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.AVIATION... (00Z TAFS) Issued at 1030 PM EDT Mon Sep 8 2025 VFR conditions are expected to persist through the TAF period. Latest guidance is suggesting that showers and thunderstorms may develop near the terminals overnight. However, there remains much uncertainty in the timing and placement of this activity. Therefore, VCSH was not included in the TAF. We will continue to monitor and VCSH may be added in subsequent updates. Near surface winds are expected to remain south to southwest between 3 to 10 knots.
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.PRELIMINARY POINT TEMPS/POPS... Key West 90 79 90 80 / 50 60 60 50 Marathon 89 79 88 80 / 50 50 50 40
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.KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. &&
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Public/Marine/Fire...MJV Aviation/Nowcasts....MJV Data Acquisition.....DR
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NWS KEY Office Area Forecast Discussion