Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
690 FXUS62 KKEY 270851 AFDKEY Area Forecast Discussion National Weather Service Key West FL 451 AM EDT Mon Jul 27 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Peak rain and thunder chances are expected today with decreasing rain chances expected for tonight, though still above normal as the active pattern continues. - Light to gentle west to northwest breezes expected this morning becoming mainly westerly this afternoon and tonight. - Heat indices may approach 105 to 110 degrees each afternoon for some Florida Keys island communities, especially in the Upper Keys. && .DISCUSSION... Issued at 445 AM EDT Mon Jul 27 2026 CIMSS products shows the Keys remain in between two massive ridges with one centered over the central North Atlantic and the other across the South-central United States. The Keys are on the eastern periphery of the ridge over the South-central states resulting in northwesterly flow down the Florida Peninsula. A trough remains in place just off the Eastern Seaboard in between the two ridges and Florida remains on the backside of this trough. At the surface, high pressure is centered across the central Gulf with the Keys on the eastern side of this high along with a surface trough over the Florida Peninsula. Marine observation platforms surrounding the Island Chain are recording northwest breezes of 5 to 10 knots as a result. KBYX radar was quiet up until an hour or two ago when showers and thunderstorms developed throughout the Florida Keys coastal waters, especially in the vicinity of the Lower Keys. GOES 19 Nighttime Microphysics imagery shows partly cloudy skies throughout the Keys with a mixture of upper level and low level clouds. Temperatures along the Island Chain are in the lower to mid 80s and dew points are in the mid 70s. .FORECAST... Surface troughing remains across the Eastern Seaboard and the western North Atlantic today and tonight. This is in between two massive ridges with one across the central North Atlantic and the other across the South-central United States. This will keep increased moisture across the area for today and tonight leading to well above normal rain chances (70%). Slightly drier air moves in tonight resulting in rain chances dropping to slightly above normal (40%). Rain chances peak today as moisture maximizes and the greatest forcing is overhead. Another trough is expected to swing down from Canada sliding across the Great Lakes, Northeast, and Mid-Atlantic. This will reinforce the current troughing already in place. At the surface, a frontal boundary will remain draped across North Florida and Georgia for the next several days. This is quite unusual for this time of the year. Due to this, it will keep a fairly unsettled pattern across north to central Florida as the moisture focuses across this area. Drier air is expected to move into the Keys due to the ridge across the Atlantic leading to decreasing rain chances. The heat will become the main story again especially from mid week onward. Daytime highs will be in the lower 90s and overnight lows in the lower 80s with some mid 80s from mid to late week. Dew points in the mid to upper 70s will lead to heat index values of 105 to 110 degrees. Light to gentle west to northwest breezes are expected today before shifting to the southwest to west by Tuesday. Breezes will freshen to gentle to moderate as the high across the Atlantic and the front across Florida act in tandem with one another leading to an increased pressure gradient, especially for mid week. After mid week, the gradient relaxes some and breezes relax back to light to gentle. && .MARINE... Issued at 445 AM EDT Mon Jul 27 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, troughing just off the Eastern Seaboard will remain for the next day or so before another trough swinging southeastward through the Great Lakes and into the Northeast reinforces the trough across the East Coast. At the surface, this will result in a frontal boundary remaining draped across the northern Florida/Georgia for much of this week. Initially, expect west to northwest light to gentle breezes before shifting to the southwest to west by Tuesday. Breezes will become gentle to moderate towards mid week before slackening back to light to gentle breezes by late week. && .AVIATION... (06Z TAFS) Issued at 445 AM EDT Mon Jul 27 2026 VFR conditions are expected to mostly persist at both EYW and MTH terminals through the TAF period. Near surface winds will remain mostly west to northwest through this evening before shifting more to the southwest to west. Well above normal rain and thunder chances are expected today. Since there has been decent agreement across the guidance, VCTS was included in both TAFs beginning at 27/12z. The best chance time for shower and thunderstorm activity appears to be during the daylight hours today. Any showers and thunderstorms will be capable of reducing CIGs and VIS to MVFR conditions, as well as producing gusty winds, and occasional lightning strikes. There is also the low probability for brief IFR conditions. && .CLIMATE... On this day in 2024, the daily record rainfall of 2.32" was recorded in Key West. Rainfall records for Key West date back to 1871. && .PRELIMINARY POINT TEMPS/POPS... Key West 89 82 90 82 / 60 30 40 20 Marathon 89 81 91 82 / 70 50 50 20 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MJV Data Acquisition.....MJV Visit us on the web at weather.gov/key Follow us on Facebook and X at: www.facebook.com/nwskeywest www.x.com/nwskeywest