Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
808 FXUS62 KKEY 020728 AFDKEY Area Forecast Discussion National Weather Service Key West FL 328 AM EDT Tue Sep 2 2025 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 327 AM EDT Tue Sep 2 2025 A broad surface low sits just off the Treasure and Gold Coasts this morning. A stationary front associated with the this low, extends almost due west across south central Florida and over the Gulf Basin. The Florida Keys, which lie to the south of this boundary, continues to see west to northwest winds this hour. Pivoting through this flow are bands of showers with embedded isolated thunderstorms. Said stationary boundary should generally stay just to our north. However, a plume of very moist air mass that stretches across the entire length of the Gulf Basin, will move in from the west and slowly begin sliding in. Given its position, it initially may affect the Lower Keys more than the rest of the Keys for today in terms of rain chances. As we go into tonight, that moisture plume will over take the rest of the region. Then it looks like it will just park itself over the Keys for the next several days. The incoming air mass has a projected PWat that is near or exceeds the 90th percentile for this time of year. This means that the air mass is more juiced than usual and could lead to periods of heavy rainfall. That in mind, we have coordinated with the Weather Prediction Center (WPC) to put the Keys under a Marginal (1 of 4) Risk for excessive rainfall starting Wednesday. As alluded to, this air mass will remain over the area through the end of the week, along with the stationary boundary. At the same time, we will remain under a broad trough that is stalled along the Eastern Seaboard. While we are not in the direct line of fire for upper level support, we will have some upper level confluence, which will only aid in saturating the entire atmospheric column. This again would further the possibility of potentially heavy, flooding rains at times. By Saturday, the stationary front and upper level trough will begin to make moves to the northeast and lift away from our area. That normally would spell drier conditions, however, lingering out across the southwest North Atlantic is an easterly undulation that will impinge on the region over the weekend. This may keep rain chances above normal through the upcoming weekend. Thereafter it looks like we will return to our more usual easterly flow and near normal rain chances. && .MARINE... Issued at 327 AM EDT Tue Sep 2 2025 A broad surface low situated along a stationary front sits off the Florida East coast, east of Lake Okeechobee with the Keys lying to the south of this boundary. This is maintaining west to northwest winds across the Florida Keys coastal waters this morning. The low and front will remain rooted in place through the next few days with undulating winds varying between northwest and southwest. Localized wind surges will be possible off the Upper Keys each afternoon starting today and going through Thursday. In addition, abundant moisture will promote above normal rain and thunder chances through the end of the week. && .AVIATION... (06Z TAFS) Issued at 327 AM EDT Tue Sep 2 2025 A lull in shower activity early this morning will likely be interrupted by more rounds of convection developing starting just before sunrise and continuing throughout the day. VCSH is included through the whole period for both TAFs, but the best first guess for the next round of shower development near by the island chain is around 10z to 11z. Any passing shower or storm will bring MVFR CIGs and VIS to brief IFR VIS along with gusty erratic winds. Outside of convection, near surface winds will be generally out of the west at near 10 knots. && .CLIMATE... On this day in Keys weather history in 1935, the eye of the Labor Day Hurricane moved northwest across Long Key and Lower Matecumbe Key in the evening, accompanied by a storm tide 15-20 feet above mean low water and an eye lull of 55 minutes on Long Key. Engineering studies indicated gusts of 150 to 200 mph from Lower Matecumbe Key to Islamorada. Over 400 people were killed, many of whom were World War I veterans working on the overseas railroad, which was destroyed. It was the strongest Hurricane ever to make landfall in the United States. && .PRELIMINARY POINT TEMPS/POPS... Key West 91 80 91 80 / 70 70 80 80 Marathon 90 80 90 79 / 60 60 80 80 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...LIW Aviation/Nowcasts....JAM 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