Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
160 FXUS62 KKEY 161032 AFDKEY Area Forecast Discussion National Weather Service Key West FL 632 AM EDT Mon Sep 16 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 507 AM EDT Mon Sep 16 2024 With the exception of a few showers that popped up during the overnight hours, the weather has been pretty quiet along the Florida Keys and coastal waters. The morning hours will remain fairly quiet, but southwesterly breezes later in the afternoon may help to trigger cloud line development similar to yesterday. Satellite obs show a messy sky this morning in terms of cloud cover, and these clouds should help to keep temperatures away from any Heat Advisory criteria for the first time in awhile. The seemingly never-ending stagnant pattern finally sees some change over the week ahead. Longwave troughing draped over the Southeast will lead to better chances for precip over the next couple of days. As the trough deepens, the southwesterly flow aloft will help to pull more moisture into the region with the majority of ensemble members favoring somewhere between 2.0" to 2.5" of PWAT. Guidance continues to show a brief period between Tuesday and Wednesday where our area is in the vicinity of a weak right entrance region of an upper level jet streak, this would help to provide the lift needed for deep thunderstorms. All of this is to say that we will continue to message the likelihood of Tuesday and Wednesday looking entirely different than the past couple of weeks. After Wednesday is where confidence drops drastically. Ensemble members are still showing the trough deepening further to some degree, but the diminished confidence is related to the disagreement among members as to just how deep the trough digs. This will have a direct impact as to how much activity we see along the island chain from Thursday onward, so it is still difficult to say with much confidence what the second half of the week could look like. Regardless, any further deepening of the trough will result in active weather and greater cloud cover as more moisture is pushed in, but the big takeaway for now is that we may be able to put heat advisories to rest for the week. && .MARINE... Issued at 507 AM EDT Mon Sep 16 2024 A Coastal Flood Advisory remains in effect for the Upper Keys, and a Coastal Flood Statement remains in effect for the Middle and Lower Keys. Ponding on the typically favored roadways will peak at the times of the morning higher high tide in the Lower and Middle Keys, with little tidal cycle relief in the Upper Keys. Other than these minor coastal flooding hazards, are no watches, warnings, or advisories in effect for the Florida Keys coastal waters. From synopsis, light and generally variable breezes will continue through Friday over the Florida Keys coastal waters. A developing low pressure system off the Carolina coast will generate a higher northerly swell off the Upper Keys for Tuesday and Wednesday. The low will deepen into an upper level trough and slowly slide south towards the Florida Peninsula by Friday. Unpredictability in the movement of this trough means confidence in the extended forecast is very low. && .AVIATION... (06Z TAFS) Issued at 507 AM EDT Mon Sep 16 2024 VFR conditions are expected to prevail at both EYW and MTH today. Another round of cloud line development will be possible today with VCSH included as a first guess at timing for associated showers near either terminal. Adjustments will likely be required as convection develops later this afternoon. Near surface winds will start out light and variable becoming southwest to west. && .CLIMATE... On this day in Keys weather history in 2023, the daily record high temperature of 97F was recorded at Marathon International Airport. This is also tied for the warmest temperature ever recorded in the month of September for the Marathon area. Temperatures records for Marathon date back to 1950. && .PRELIMINARY POINT TEMPS/POPS... Key West 90 81 89 81 / 40 40 50 40 Marathon 91 82 91 81 / 40 40 50 50 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 PM EDT Tuesday for FLZ076. GM...None. && $$ Public/Marine/Fire...DP 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