Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
856 FXUS62 KKEY 090216 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1016 PM EDT Tue Sep 8 2026 ...New DISCUSSION, MARINE, AVIATION... .KEY MESSAGES... - Moisture will linger across the region through the end of the week, supporting rain and thunderstorm chances. - The primary threat for any stronger thunderstorms will be dangerous lightning strikes. When thunder roars, go indoors. If on a boat, stay low, or go below. - Heat index values will range from 100-108 degrees daily with little relief from the muggy conditions overnight. Know the signs of heat stress, take frequent breaks, and stay hydrated. && .DISCUSSION... Issued at 1016 PM EDT Tue Sep 8 2026 A quiet late afternoon came to an end this evening over the waters north of the Florida Keys. Shortly before sunset, isolated showers rapidly developed into thunderstorms just north of Key West. Additional thunderstorms that developed over the Everglades also sent outflow boundaries towards the Keys, one capable of generating wind gusts up to 34 knots. This burst of convection is why, despite a nearly clear radar for most of the day, we have been keeping shower chances near normal. Typical weather conditions for the Keys in September means even tiny showers can rapidly build into 40,000 to 50,000 ft behemoths. Expect showers that do form overnight to develop and collapse rapidly. Away from the nearby showers and thunderstorms, conditions remain relatively benign tonight. Anemometers along the reef were too far from the thunderstorms to observe downdrafts. Temperatures along the Keys are slowly decreasing towards the lower 80s. CIMSS-MIMIC PWAT estimates still calculate over 2 inches over the Florida Keys. Nighttime showers have also been able to generate layers of cirrus clouds that will linger over the waters surrounding the island chain. Surface winds are forecast to become prevailing east to southeasterlies as the Atlantic ridge lifts north, away from Southern Florida. We may see shower development ahead of freshening breezes. However, for the typical person in the Keys? Tonight, expect lows in the lower to mid 80s once again, light winds, and short lived showers. Tomorrow, brace for highs near 90, dew points in the upper 70s, heat indices from 100 to 105 degrees, and a chance of showers. && .MARINE... Issued at 1016 PM EDT Tue Sep 8 2026 No watches, warnings, or advisories are in effect for the Florida Keys coastal waters. From synopsis, Florida Keys coastal waters will initially remain under a broad nebulous pressure pattern tonight, leading to light and variable winds. By early Wednesday, the western extent of the Atlantic Ridge will begin building in and allow breezes to become more easterly while freshening to gentle to moderate. Waves of low- level moisture pushing across the Keys will support elevated rain and thunder chances through Sunday. && .AVIATION... (00Z TAFS) Issued at 1016 PM EDT Tue Sep 8 2026 VFR conditions will prevail at EYW and MTH. Surface winds will be light and variable early in the period, but are forecast to become prevailing east to southeasterlies. Light winds and copious moisture indicates shower and thunderstorms may be able to form near the terminals and cause brief bouts of sub VFR conditions and possible VCTS. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 92 82 92 / 30 30 30 50 Marathon 84 91 83 90 / 30 30 50 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...AJP Aviation/Nowcasts....AJP Data Acquisition.....DM Visit us on the web at weather.gov/key Follow us on Facebook and X at: www.facebook.com/nwskeywest www.x.com/nwskeywest