Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
982 FXUS62 KKEY 200851 AFDKEY Area Forecast Discussion National Weather Service Key West FL 451 AM EDT Mon May 20 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 451 AM EDT Mon May 20 2024 This morning has felt like summertime in terms of convection across the Florida Keys. Mesoscale boundaries have been the main trigger mechanism for convection, with multiple outflow boundaries still present on radar. KBYX is currently detecting scattered convection within the forecast area, with most of the storms aligning with or being adjacent to the island chain. The strongest activity is currently located near the Upper and Middle Keys. Good upper- level support has been very evident across most of the region, with radar derived hail hedging close to 2" inches in the waters across the Bahamas and even in a storm that plowed through the distant Straits earlier. The activity closer to home has not been able to fire up as well until just recently, which may be due in part to drier air in the mid- levels sampled by last night`s 00Z sounding. The storms that have been able to overcome this drier air have been able to tap into the fat CAPE profiles and have gone nuts. Panning out from the Keys, a trough is extending across the western North Atlantic, dragging a frontal boundary in its wake. This front has made it almost to Central Florida. A good environment will remain in place for scattered showers and isolated thunderstorms today. Winds will continue to shift to the north ahead of the aforementioned frontal boundary, which will continue to usher in lower dew points. Dew points have already dropped roughly 3-5 degrees over the past few hours, which has made quite an impressive difference in the level of comfort when walking outdoors. These lowered dew points and temperatures will keep the Keys below the threshold for Heat Advisories through the remainder of the week. Winds will remain generally from the northwest to north through Tuesday night, briefing becoming variable on Tuesday. Decent moisture will remain in place through Wednesday, which could help spur on mesoscale processes such as cloud lines during this timeframe. Guidance has trended downwards on the higher rain chances through Wednesday, so have capped PoPs at 30%. Forecast rain chances may continue to decrease, depending on how much dry air can invade into the mid-levels. Easterly flow will return by mid-week as high pressure really builds back in, which will allow for dew points to gradually rise back into the mid 70s. As of now, MOS guidance does not hint at any of the oppressive dew points we have been tormented with over the past few days returning through the extended forecast luckily. && .MARINE... Issued at 451 AM EDT Mon May 20 2024 There are no watches, warnings, or advisories in effect for the Florida Keys coastal waters. From synopsis, a frontal boundary currently draped across north Central Florida has helped the wind field across the Florida Keys become somewhat nebulous this morning. Breezes have begun to shift to the west to northwest in the western waters. By this afternoon, breezes will veer to the northwest and increase. Tuesday through Wednesday, breezes will gradually shift to the east as high pressure in the western North Atlantic builds back in across the region. && .AVIATION... (06Z TAFS) Issued at 451 AM EDT Mon May 20 2024 Widely scattered showers with a few isolated thunderstorms will wax and wane in the vicinity of the island chain early this morning. After sunrise, this activity will diminish with slight rain chances persisting throughout the rest of the day. VCTS is included at both terminals until we expect this activity to die down, though any shower passing over a terminal may result in MVFR CIGs or VIS and will be TEMPO`ed as needed. Near surface winds will start out light of the southwest, becoming northwest at 5 to 10 knots this afternoon. && .CLIMATE... On this day in 1932, the daily record rainfall of 3.83" was recorded in Key West. Rainfall records date back to 1871. && .PRELIMINARY POINT TEMPS/POPS... Key West 90 79 89 79 / 20 30 30 30 Marathon 89 80 89 80 / 30 30 30 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...NB 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