Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
847 FXUS62 KKEY 011001 AFDKEY Area Forecast Discussion National Weather Service Key West FL 601 AM EDT Wed Jul 1 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Conditions will be favorable for island cloud line formation near portions of the Florida Keys today. Cloud line development will carry the risk of waterspouts. - A chance of showers with a slight chance of thunderstorms will persist through tonight. - Light to gentle east to southeasterly breezes will occasionally become variable through Wednesday evening. && .DISCUSSION... Issued at 600 AM EDT Wed Jul 1 2026 Weather conditions during the overnight shift have remained mostly unremarkable outside of a few isolated showers and thunderstorms, mainly across the Florida Straits. Only a handful of lightning strikes were detected by the GOES-19 satellite, especially before midnight. Along the island chain, temperatures have sat in the lower to mid 80s with dew points in the mid to upper 70s. The exception, similar to yesterday morning, is on Big Pine Key where radiational cooling brought temperatures down to the upper 70s. Amplified ridging across the eastern U.S., centered somewhere around western Virginia, will continue to keep sensible weather mostly benign. Forecasting when, and where, showers and thunderstorms will pop up feels almost impossible, because we have two different mechanisms we are depending on the trigger activity. The light and variable wind field opens the door for possible cloud line development either over, or adjacent to, portions of the island chain during the afternoon. This would result in very localized pockets of showers and thunderstorms, as well as a possibility for waterspouts. The second trigger for activity comes from the afternoon thunderstorms over the mainland that stem from sea breeze convergence. This activity can either drift into our forecast area, or outflow boundaries can collide and trigger new activity, which is essentially what we saw yesterday. All of this is to say that the ingredients for some showers and thunderstorms are there as is pretty typical for July in Florida. The question is simply where and when does this activity pop up. After today, the ridging will nudge toward the Atlantic coastline. While this happens, a pulse or two of vorticity will undercut the ridge and clip the area, which will nurture an environment conducive to an increase in showers and thunderstorms. This isn`t a pattern evolution that would favor a widespread washout over the holiday weekend, but both deterministic and ensemble guidance show some deeper moisture and better instability that would translate to an increase in the amount of activity somewhere within the boundary of our CWA. Probabilistic guidance favors activity during the day on Independence Day, and if we can work over the environment, that may give us a window of drier conditions for anyone celebrating outdoors. However, that hyperlocal scale is unrealistic to try and forecast for three days out, so the pattern will continue to be monitored. && .MARINE... Issued at 600 AM EDT Wed Jul 1 2026 There are no watches, warnings, or advisories in effect for the Florida Keys waters. From synopsis, generally east to southeast breezes will become variable at times today outside of any showers or thunderstorms that may development. Active weather will depend on if, or when, a cloud line can develop along or near the island chain. Cloud line development will also increase the chances for waterspouts. Afternoon showers and thunderstorms over the mainland may also drift into our local waters. High pressure gradually builds back across the area Thursday with peaks and lulls in the wind field resuming at that time. && .AVIATION... (06Z TAFS) Issued at 600 AM EDT Wed Jul 1 2026 While VFR conditions will prevail at both island terminals, there is a low chance, around 20 percent, of showers and thunderstorms after 15Z. Opting to leave a broadbrushed VCSH in the TAFs, and will try to narrow the timing once showers initiate. If any of this activity moves over either terminal, the most likely impact will be lowered CIGs. Surface winds will generally be light and variable, but are expected to resume a uniform southeasterly direction at 5 to 10 knots. && .OF NOTE IN KEYS WEATHER HISTORY... On this day in 1957, the Key West Weather Bureau moved to the airport. && .PRELIMINARY POINT TEMPS/POPS... Key West 92 83 92 83 / 20 30 20 10 Marathon 89 82 89 83 / 20 20 20 10 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...DP Aviation/Nowcasts....DP Data Acquisition.....BT/RG Visit us on the web at weather.gov/key Follow us on Facebook and X at: www.facebook.com/nwskeywest www.x.com/nwskeywest