823 FXUS62 KKEY 200059 AFDKEY Area Forecast Discussion National Weather Service Key West FL 859 PM EDT Mon Apr 19 2021 .DISCUSSION... A fairly active convective evening over the Florida Keys coastal waters. Several thunderstorms have developed from cumulus fields over the Florida Straits and progressed towards the northeast near 20 knots. Storm tops have been just shy of 45 kft, and have been more organized than a typical pulse thunderstorm scenario. One thunderstorm north of Key West breifly popped above 50 kft.This is not surprising since the Key West evening sounding revealed a good degree of convective instability. Precipitable water values are up around 2 inches, and the boundary layer from 700mb down is close to saturation. ML CAPE is approaching 3000 J/kg with virtually no inhibition. Therefore, any lift from boundaries or thunderstorm outflow will produce a convective cell. New cells are now forming well southwest of the Lower Keys - also moving swiftly towards the northwest. So it would seem that this convection will last well into the overnight hours. && .MARINE... Scattered showers and thunderstorms will impact the Keys coastal and nearshore waters for the remainder of the evening and overnight. Some of these storms could be strong, producing wind gusts approaching 34 knots. Storms that do develop will be moving rapidly towards the northwest, between 20 and 25 knots. Winds will be generally from the southwest around 10 knots, but can dramatically shift and strengthen in the vicinity of showers and storms. && .AVIATION... Although VFR conditions will generally prevail at both the Key West and Marathon terminals, passing strong showers and storms can result in brief periods of MVFR or even IFR conditions, mainly at the Key West terminal overnight. There is not enough certainty in the timing and location of the storms as the evening progresses, so there may be amendments to the terminal forecast as events unfold. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...Devanas Aviation/Nowcasts....Devanas Data Acquisition.....KR Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest