Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
512 FXUS62 KKEY 150755 AFDKEY Area Forecast Discussion National Weather Service Key West FL 355 AM EDT Sat Mar 15 2025 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 311 AM EDT Sat Mar 15 2025 Early morning hours indicate those in the Florida Keys should not beware the Ides of March. GOES East satellite scans highlight shallow, non precipitating clouds over the Straits of Florida and Hawk Channel. The KBYX radar observations spot only non meteorological phenomena. While these features are similar to yesterday morning, the atmosphere is changing. Winds at the reef have freshened to moderate breezes while gentle to moderate southerly breezes are present along the island chain. Veering winds increased temperatures to the mid 70s across the Keys. Dew points remain near 70, and no features on radar or satellite suggest the pattern will change in the next few hours. Shifting from the local to regional perspective, the Ides of March become troublesome. GOES East observations across the country identify a very potent surface low located over the upper Midwest with a pronounced cold front extending south towards the southern United States and a secondary low developing over the southern Plains. The Storm Prediction Center issued a High Risk for convection today for portions of Mississippi and Alabama due to this front. Over the Keys, the strengthening pressure gradient thanks to this low pressure system and a building Atlantic high will support freshening breezes over the weekend. The aforementioned cold front will sweep south into the Gulf on Sunday, and model ensembles are reaching a consensus that frontal passage across the CWA is most likely on Monday afternoon. Given the increase in moisture, instability (500-1000 J/kg of CAPE), rapidly veering winds, the presence of a subtropical jet core above the Keys, and a source of lift from the front, a 10% chance of thunderstorms is included for Sunday Night and Monday. Windy conditions are also likely on Monday post front. Model guidance continues to drop dew points further behind the front. Statistical guidance calculates a possible dew point in the 40s at Key West on Tuesday with cold air lingering a bit longer across the Keys. Expect near nil rain chances mid week given the very low dew points. Mid week, a weak high pressure system over the southeastern United States will allow weaker winds and mostly clear skies through the work week. Model ensembles calculate another low pressure system developing over the eastern United States late in the week, and breezy conditions are possible by the end of next week. Overall, all attention is on the Mississippi Valley today while the greatest impacts for the Florida Keys are likely on Monday. Check back later, dew points could drop even more by Sunday morning. && .MARINE... Issued at 311 AM EDT Sat Mar 15 2025 Small Craft Should Exercise Caution for Increasing Winds across most of the Keys Coastal Waters, and Small Craft Should Exercise Caution over the Straits of Florida. A Small Craft Advisory may be required for the Straits of Florida tonight. At the Sand Key C-MAN station, southeasterly breezes of 15 knots were measured. From synopsis, breezes are freshening across the Florida Keys coastal waters today while the Atlantic High builds in response to a very strong surface low centered over the Midwest. Small Craft Advisories may be required for portions of the Florida Keys coastal waters, primarily Atlantic-side, tonight through Sunday afternoon. A cold front associated with the low pressure system is forecast to transit across the Florida Keys on Monday. Peak shower coverage with isolated thunderstorms is expected ahead of the front from Sunday Night to Monday. Fresh, occasionally strong, breezes are likely post frontal passage. High pressure will set up over the southeastern United States mid week which will allow breezes to slacken to gentle to moderate. && .AVIATION... (06Z TAFS) Issued at 311 AM EDT Sat Mar 15 2025 VFR conditions will prevail at both EYW and MTH today. Bouts of SCT025 coverage and near nil rain chances will continue as near surface winds blow out of the east to southeast starting at 8 to 10 knots, before increasing to 10 to 12 with some occasional gusts near 20 knots. && .PRELIMINARY POINT TEMPS/POPS... Key West 84 74 84 69 / 10 10 10 40 Marathon 83 75 84 71 / 10 10 10 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...AJP Aviation/Nowcasts....JAM 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