Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
227 FXUS62 KKEY 010853 AFDKEY Area Forecast Discussion National Weather Service Key West FL 453 AM EDT Mon Sep 1 2025 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 455 AM EDT Mon Sep 1 2025 A lull between convective waves is underway across the Florida Keys this morning. After yet another active period ranging from yesterday afternoon to evening, GOES-19 infrared imagery shows a blanket of residual cloud debris painted across our area. KAMX radar did note a few pulse thunderstorms popping up around the Lower Keys a couple hours ago, but those have since deteriorated in our overworked environment. Their influence to our sensible weather still lingers however, as their outflow was recently detected on our offshore observation platforms along the west side of the Reef as light northwesterly breezes. The rest of the Reef observations are currently measuring in gentle southwest breezes. Temperatures along the island chain are a touch lower than this time yesterday with values near 80. Dewpoints are still floating around the mid to upper 70s. While it may be a different day, the same forecast as the last few days is on tap in the short term. Troughing is anchored across the Eastern Seaboard with a surface low broadly situated across Florida promoting our westerly flow. A weak cyclonic circulation was actually observed on KMLB just off the east coast a few hours ago. Last night`s KKEY 00z sounding has both westerly flow up into the mid levels and an extremely moist profile. CIMSS MIMIC PW indicates this moist air is found across the Gulf and stretching across the Keys over The Bahamas. No changes in the synoptic pattern will result in a very similar forecast to yesterday`s but with a bit extra. Considering how well showers have been proliferating in this environment and how high rain chances are in numerical guidance, opted to move to likely PoPs for today and extending into tonight. Expect another wave of numerous showers and scattered thunderstorms percolating through out the day with occasional lulls before the next spike in activity. The long term forecast still holds onto this pattern throughout the work week. As the previously mentioned trough continues to sit along the periphery of the Bermuda High, fluctuations in winds will be generally mesoscale driven with the thermal low freshening breezes during the day and the overall windfield generally only being affected by storm outflow. This weekend, high pressure building back into eastern CONUS will finally spread over mainland Florida returning our flow back to the usual easterlies. As little change is currently expected, persistence continues to be the best forecast with above normal PoPs at 50% along with a chance of thunderstorms. High and low temperatures will stay near 90 and in the lower 80s (outside of precipitation) respectively as breezes generally remain out of the west. && .MARINE... Issued at 455 AM EDT Mon Sep 1 2025 No watches, warnings, or advisories are currently in effect for the coastal waters of the Florida Keys. From synopsis, somewhat unusual westerly breezes prevail across the Florida Keys as our area is situated between ridging in the Caribbean and troughing along the Eastern Seaboard. This pattern will remain relatively unchanged throughout the forecast as the trough lazes over the east coast of CONUS while a surface low develops along the Georgia coastline. This low is progged to meander off into the western North Atlantic and rest on the west edge of the Bermuda High promoting an extension of the already established pattern in the Keys. && .AVIATION... (06Z TAFS) Issued at 455 AM EDT Mon Sep 1 2025 Spotty showers near the terminals this morning will dissipate prior to dawn. However, another round of showers and thunderstorms is expected to develop. Given the trends lately, have introduced VCSH as early as 15Z but it may take until closer to 18Z to see convection fire. Any passing shower or storm will bring MVFR to brief IFR conditions along with gusty erratic winds. Outside of this activity, winds will generally be southwest to west. && .CLIMATE... In 1980, the daily record rainfall of 3.25" was recorded in Key West. In 1971, the daily record rainfall of 2.21" was recorded in Marathon. Daily precipitation records for Key West date back to 1871, and date back to 1950 for Marathon . Of note, in 1933, a Hurricane moved west northwest through the Straits about 60 miles south of Key West, where a minimum pressure of 29.61" was recorded along with a peak sustained winds of 42 mph. Little damage was reported in Key West. && .PRELIMINARY POINT TEMPS/POPS... Key West 92 81 92 81 / 70 50 60 50 Marathon 90 80 90 81 / 70 60 60 50 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...JAM Aviation/Nowcasts....LIW Data Acquisition.....JAM Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest