Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
297 FXUS62 KKEY 150858 AFDKEY Area Forecast Discussion National Weather Service Key West FL 458 AM EDT Thu Aug 15 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 458 AM EDT Thu Aug 15 2024 A weak ridge axis continues to extend across South Florida and the Florida Keys. Light and variable winds have prevailed overnight, and with mostly clear skies, have led to radiational cooling on some of the protected areas on the larger islands. The RAWS station on Big Pine is measuring a temperature of 78 degrees, which is almost chilly in comparison to the temperatures we have been experiencing these past few days. A strip of enhanced moisture remains across the island chain, but due to the lack of a triggering mechanism, showers have struggled to develop overnight. KBYX is detecting a few isolated showers in the Straits of Florida as well as the SE Gulf, but there has been no measurable rainfall on land over the past few hours. An upper level trough sprawled across the Eastern Seaboard will dip southward today, fracturing the ridge axis. A boundary associated with this trough will gradually slide southward down the Florida Peninsula. Winds will become west to northwest this evening as a result, but will be variable for a majority of the weekend thereafter. In terms of rainfall today, another cloud line will likely develop today and bring measurable rainfall. Steering flow will become more northerly tonight, which could bring convection from the mainland towards the island chain. A band of higher moisture content will seep southward along the aforementioned boundary, which could lead to higher rain chances Friday through Saturday. Have increased rain chances for Saturday, as this is when the most favorable environment is expected at this time. Some model guidance has this washed out boundary drifting through the Keys later this weekend, which could provide us with enough of a drop in dew points to keep up out of Heat Advisory criteria through the first part of next week. For now, have issued a Heat Advisory for today, with another likely tomorrow due to heat indices eclipsing 108 degrees. It will take a while for the Atlantic ridge to reestablish itself as the upper trough takes its time to lift to the northeast. As a result, winds will remain generally light and variable through the first part of next week. Mesoscale processes will dominate convective development through the extended forecast, and near normal rain and thunder chances are expected outside of the first part of the weekend. && .MARINE... Issued at 458 AM EDT Thu Aug 15 2024 There are no watches, warnings, or advisories in effect for the Florida Keys coastal waters. An Atlantic ridge axis stretching west across the Florida Keys will support light to gentle breezes through this afternoon, generally variable. Breezes will shift to the northwest by tonight, as a trough dips south along the Eastern Seaboard. As the ridge axis fractures over the Florida Peninsula, breezes will become more chaotic Friday through Sunday. Once the ridge reestablishes itself late in the weekend through early next week, light south to southwest winds will resume. Tropical Storm Ernesto north of Puerto Rico will likely impact the island of Bermuda as a hurricane Friday night through Saturday. && .AVIATION... (06Z TAFS) Issued at 458 AM EDT Thu Aug 15 2024 VFR conditions are expected to prevail at both EYW and MTH today. Near normal rain chances are expected today as cloud lines may form along the island chain this afternoon. As timing and exact location are uncertain, left mention out of either TAF for now. Near surface winds will be light and variable. && .CLIMATE... On this day in 1920, the daily record low temperature of 70F and the daily record rainfall of 2.40" 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 93 83 92 82 / 30 20 30 30 Marathon 93 83 92 82 / 40 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