FXUS62 KKEY 191524 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1124 AM EDT Tue May 19 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Very warm and humid conditions over the next few days will lead to a generally moderate risk of heat illness with periods of high risk conditions. - Rain and thunder chances will remain on a plateau through tonight, and gradually decline thereafter. - Breezy conditions continue for the Island Chain through this evening. Small Craft Should Exercise Caution across all the Florida Keys coastal waters today. && .DISCUSSION... Issued at 1124 AM EDT Tue May 19 2026 A busy day for KBYX radar this morning. Showers have remained active throughout the coastal waters through much of the morning while occasionally allowing for brief downpours on the island chain. A majority of the island chain has experienced some rain, though the Upper Keys have lacked due to some drier air up on that side of the island chain. GOES-19 Satelitte reveals that outside of showers locations, skies are partly cloudy for most of the area. Temperatures across the island chain are in the mid 80s currently. Along the Reef, marine observation sites are recording 15 to 20 knots. A Small Craft Should Exercise Caution headline is in place for all of the Florida Keys waters for the freshened breezes through this evening. Conditions are expected to remain similar for the remainder of the day with scattered showers struggling to become thunderstorms but still dropping a few tenths of an inch of rainfall when impacting any location. && .PREVIOUS DISCUSSION... Issued at 440 AM EDT Tue May 19 2026 CIMSS products shows a mean layer ridge remains in place across the western North Atlantic. However, embedded within the ridge is an upper level disturbance located to the north of the Bahamas. At the surface, a high pressure system remains in place to the north of Bermuda. Marine observation platforms surrounding the Island Chain are recording mainly east breezes of 15 to 20 knots as a result. Moisture undulations continue to rotate around the ridge with deeper moisture currently moving through as GOES 19 Total Precipitable Water (TPW) shows estimated PWAT values of 1.8 to 1.9 inches moving through the Keys. KBYX radar has been active for much of the overnight with scattered showers moving in an east to west fashion through the Keys with occasional showers impacting the Island Chain. The showers have been struggling to develop vertically due to the northwest flow aloft attributed to the upper level disturbance to the east. This is tilting the clouds to the south and thus choking off the updrafts causing the activity to weaken as fast as they develop. GOES 19 Nighttime Microphysics imagery shows partly cloudy skies throughout the Keys. Temperatures along the Island Chain are in the lower 80s and dew points are in the mid 70s. .FORECAST... Surface high pressure across the western North Atlantic will continue to dominate the Keys weather for the next several days. The high will be at its strongest today with gradual weakening each day thereafter. Therefore, breezy conditions are expected to continue through this evening out of the east with modest slackening afterwards. Moisture is expected to remain elevated through at least Wednesday night before slightly drier air rotates in from the southeast for late week into the holiday weekend. This will result in chances of rain becoming slight chances. Instability will also remain elevated keeping thunder in the forecast throughout the period. Temperatures will remain quite consistent through the week with highs in the upper 80s to occasionally 90 degrees and overnight lows in the lower 80s to perhaps near 80 degrees with any showers. && .MARINE... Issued at 1124 AM EDT Tue May 19 2026 Small Craft Should Exercise Caution headlines are in effect for all Florida Keys coastal waters through this evening. From synopsis, surface high pressure centered north of Bermuda will continue to promote moderate to fresh east to southeast breezes through tonight. Highest breezes will prevail through this evening. Breezes will then slowly slacken before the weekend with peaks expected during the evenings and lulls during the day. Rain and thunder chances will remain above normal through much of the week. && .AVIATION... (15Z TAFS) Issued at 1124 AM EDT Tue May 19 2026 VFR conditions will prevail at both EYW and MTH through the TAF period. Scattered showers will continue to move northwest through the Straits into the island chain through the afternoon, therefore, VCSH is included at both EYW and MTH. If direct shower impact is to occur TEMPOs will be included for reduced visibilities, lower cloud ceilings, and gusty winds. Near surface winds outside of convection will be easterly at near 10 knots. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...AP Aviation/Nowcasts....AP Data Acquisition.....AP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest