Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
777 FXUS62 KKEY 200242 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1042 PM EDT Thu Sep 19 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 1042 PM EDT Thu Sep 19 2024 Despite the continued lack of flow, convection has been able to sustain itself through a multitude of boundary collisions mainly in the Gulf Waters near the Dry Tortugas. This activity has not moved much, so some areas over water received up to 4" of rainfall. Other than a few meager showers that moved over the Upper Keys, the island chain has remained rain-free over the past few hours. The 00Z sounding sampled an unstable environment this evening, with decent CAPE values and above normal moisture for this time of year. The drier air that sampled last night has been replaced with deep tropical moisture. Lower heights aloft were once again seen this evening as the expansive troughing along the Eastern Seaboard extends down across the Keys. The quandary of the past few nights remains the same tonight. We have the ingredients for convective development, but also are lacking flow and a triggering mechanism. There are a few boundaries still lingering across the forecast area, and once sparked, can produce lots of rainfall as we saw near the Dry Tortugas. The question is whether the mostly untapped environment aside from the western waters will be able to erupt. It is very hard to drop rain chances based on the environmental parameters except for the lackluster wind profile. Have decided to keep high end chance PoPs for tonight. No changes were needed to the forecast. && .MARINE... Issued at 1042 PM EDT Thu Sep 19 2024 Light and often variable breezes will continue overnight into tomorrow due to a persistent trough/low near the Atlantic Coast and a weak high east of the Bahamas. Heading into this weekend, the low will meander further out into the Atlantic as ridging expands its control across the southeastern United States. As a result, winds will finally begin to take on a dominant, yet light, broadly easterly direction. Confidence in the extended remains very low and will be highly dependent on the expected formation of a low in the northwestern Caribbean Sea. Any development would have a good chance of freshening east to southeasterly breezes. 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. Boaters can expect less clearance under fixed bridges. && .AVIATION... (00Z TAFS) Issued at 1042 PM EDT Thu Sep 19 2024 VFR conditions will prevail at both island terminals through the TAF period. The Florida Keys still remain in a wetter pattern, so have decided to include VCSH by daybreak tomorrow morning which has typically been the trend of convection, if not earlier. There is a chance for passing showers overnight, but the timing and location is somewhat uncertain, so have left mention of showers out for now. Surface winds will be light and variable outside of any convection. && .CLIMATE... On this day in 1963, the daily record rainfall of 4.23" was recorded in Key West. Rainfall records date back to 1871. && .PRELIMINARY POINT TEMPS/POPS... Key West 81 90 82 90 / 50 40 30 30 Marathon 80 90 81 90 / 50 40 30 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Coastal Flood Advisory until 5 PM EDT Friday for FLZ076. GM...None. && $$ Public/Marine/Fire...NB Aviation/Nowcasts....NB Data Acquisition.....MJV Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest