Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
939 FXUS62 KKEY 121940 AFDKEY Area Forecast Discussion National Weather Service Key West FL 340 PM EDT Mon Aug 12 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 142 PM EDT Mon Aug 12 2024 The expected SAL plume is nearing the island chain this afternoon. Shower coverage decreased dramatically over the past few hours and the skies are milkier. Temperatures are near or above 90 and dewpoints are in the upper 70s. East to southeast winds at the Reef average 6 to 9 knots. .FORECAST... Water vapor imagery highlights a TUTT cell to the southeast of Bermuda, lowering heights across the Eastern Seaboard, mean-layer ridging over the southern Plains, and a chaotic maelstrom of weakened flow across the Caribbean and the Gulf of Mexico. The mean-layer ridge will slide east-southeast tonight through Wednesday night, in concert with equatorward expansion of the upper-level trough (Eastern Seaboard) into the western North Atlantic. PTC5 will lift northward in response to the upper- level trough, after passage through the Greater Antilles. Meanwhile, steering flow initially from the east 10 to 13 knots will shift to the northeast and decrease. Remarkably, a cool front will sag southward through Central Florida Thursday and Thursday night, including dewpoints in the upper 60s for portions of south-central Florida. This front will lyse quickly over South Florida Friday through Saturday, followed by the low level ridge trying to lift northward through the Keys Sunday through Monday. Through the short term, SAL tonight and slim rain chances will be replaced by near to above normal rain chances on Tuesday. The chances on Tuesday will be due to the undulation in the easterlies now nearing Andros. Thereafter, with a shift to northeast or variable steering, rain/thunder chances will be ruled by mesoscale circulations along the island chain and also from convective outflows emigrating from the Mainland. The front sagging into South Florida should be a focus for likely rain chances for the Mainland, and climatology favors the Keys staying on the tropical side of this dying front. && .MARINE... Issued at 142 PM EDT Mon Aug 12 2024 There are no watches, warnings, or advisories currently in effect for the coastal waters of the Florida Keys. An Atlantic ridge axis stretching west across Florida will support gentle to moderate easterly breezes through Wednesday. Breezes will slacken and veer to the northwest by Thursday night as a trough dips south along the Eastern Seaboard. As a result, breezes will become more chaotic by Friday as the ridge axis fractures over Florida. A tropical disturbance to the east of the Bahamas will move north towards Bermuda Friday and Friday night. && .AVIATION... (18Z TAFS) Issued at 142 PM EDT Mon Aug 12 2024 A shallow dry air mass will transit across the island chain tonight and tomorrow morning and keep VCSH out of the TAFs for EYW and MTH. Surface breezes will remain east to east southeasterly throughout the TAF period with speeds between 5 and 10 knots. && .CLIMATE... On this day in 1926, the daily record low temperature of 71F and the daily record rainfall of 2.59" were both recorded in Key West. Temperature records date back to 1872 and rainfall records date back to 1871. && .PRELIMINARY POINT TEMPS/POPS... Key West 84 92 84 92 / 10 30 30 30 Marathon 83 92 83 92 / 10 30 30 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Heat Advisory until 7 PM EDT this evening for FLZ076>078. GM...None. && $$ Public/Marine/Fire...CLR Aviation/Nowcasts....AJP Data Acquisition.....AJP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest