835 FXUS62 KKEY 290232 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1032 PM EDT Sun Jun 28 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Slight chances of showers and thunderstorms will persist through the middle of the week. - Mainly gentle to moderate east to southeast breezes will persist overnight across the Florida Keys coastal waters. - There will be little relief in the warm temperatures overnight, with minimum temperatures near record values in the lower to mid 80s for most communities. && .DISCUSSION... Issued at 1028 PM EDT Sun Jun 28 2026 CIMSS products shows the beginning of what will be quite an amplified pattern across the lower 48. A deep mean layer ridge is currently strengthening and building across the ARK-LA-TEX region along with deep mean layer troughing across the Intermountain West. However, there is another subtly feature undercutting the ridge across the Keys and Cuba currently. In order to see this feature, we need to look at the GOES 19 Mid-level water vapor imagery. While looping the last few hours, we notice a weak cyclonic flow in the imagery or a weak tropical wave/trough moving slowly westward. This may be one of the factors attributed to the increased shower and thunderstorm activity today across the Keys as well as across the Southwest Florida mainland. KBYX radar has remained slightly active this evening with a couple showers, occasionally a thunderstorm, across the SE Gulf waters and the eastern Straits of Florida. Temperatures along the Island Chain are in the mid 80s and dew points are in the mid 70s. At the surface, an Atlantic ridge extends westward through the Keys and into the Gulf. Marine observation platforms surrounding the Keys are observing east to southeast breezes near 10 knots as a result. .SHORT TERM FORECAST... The 00z evening sounding shows a mostly dry vertical profile. The PWAT value measured was 2.01 inches which is a little below the 90th percentile for the date. There is also plenty of instability (CAPE) in the profile with a value measured of 3251 J/kg. This is a very high value and most likely one of the reasons why most of the activity today became thunderstorms. The cells were feeding off the instability and didn't need much to make them become a thunderstorm. We expect it to remain fairly quiet overnight since we are lacking some of the ingredients to really get storm activity going. However, any shower that does develop will be capable of becoming a thunderstorm quite easily due to the impeccable amount of instability across the area. No changes to the ongoing forecast as a result. && .MARINE... Issued at 1028 PM EDT Sun Jun 28 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a broad high pressure system centered over the North Atlantic will continue to extend westward to the Florida Peninsula through early week. This will support bouts of light to gentle breezes that may freshen to gentle to moderate at times, mainly in the overnight hours. Starting late Monday, a frontal boundary will press south across the Florida Peninsula and stall across central Florida. This will act to weaken the high and allow for slackening breezes through Thursday. Thereafter, breezes will resume a cycle of overnight peaks and daytime lulls. && .AVIATION... (00Z TAFS) Issued at 1028 PM EDT Sun Jun 28 2026 VFR conditions are expected to persist through the TAF period at both EYW and MTH terminals. Near surface winds are expected to remain mostly easterly through the period. While most of the overnight is anticipated to remain rain free, there is the slight chance for a few nearby showers near the terminal Monday morning. There was decent consensus across the guidance leading to at least average confidence, therefore, VCSH was included in the TAF beginning 29/12z Monday. There is also the risk for an afternoon cloud line. && .PRELIMINARY POINT TEMPS/POPS... Key West 92 84 92 83 / 50 20 20 20 Marathon 89 83 90 84 / 50 20 20 10 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MJV Data Acquisition.....DR Visit us on the web at weather.gov/key Follow us on Facebook and X at: www.facebook.com/nwskeywest www.x.com/nwskeywest