Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
504 FXUS62 KKEY 161900 AFDKEY Area Forecast Discussion National Weather Service Key West FL 300 PM EDT Tue Jul 16 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 259 PM EDT Tue Jul 16 2024 Shower and thunderstorm activity has certainly quieted down quite a bit from this morning. This is thanks to a slug of dry air moving in from the east, which is effectively shutting down almost all convection. There is a couple of broken lines of convection that remain active off the Lower Keys. These lines have been cycling through showers and thunderstorms pretty much all afternoon. Meanwhile, the dry air is taking a bit longer to mix down to the surface and so we still have dew points in the mid to upper 70s. This combined with temperatures in the upper 80s to lower 90s has at times created heat index values near or exceeding 108. Thankfully we have not had at least 2 hours consecutively of a heat index of 108 or higher and thus were able to refrain from issuing a heat advisory. However, it is still hot outside and residents should take precautions nonetheless if doing any outdoor activities for an extended period of time. .FORECAST... An Atlantic ridge continues to extends it reach across the Florida Peninsula and over the Gulf of Mexico. This will maintain east to southeast breezes across the region through the coming days. The most recent slug of dry air will shift to our west by Wednesday afternoon. However, even with that being said, boundary layer moisture will be slow to return with much gusto. Therefore, even though we will continue to see a prolonged period of easterly winds, rain chances are only slightly higher than climatology this week. As we go into the weekend, the pattern becomes more interesting. An easterly undulation will pivot through starting as early as Saturday night. Better moisture will accompany this undulation as it moves across south Florida. At the same time a TUTT will be sliding westward around the base of the Atlantic Ridge. There is a potential for the features to phase and would lead to higher rain chances than currently advertised. However, timing is everything and therefore will stay at or just slightly below middle of the road for now. Otherwise, no tropical threats on the horizon and no air mass changes expected. Daytime highs will stay in the 90s with overnight low dipping into the lower 80s. Dew points will remain elevated and a threat for Heat Advisory conditions will persist through the next 7 days. && .MARINE... Issued at 259 PM EDT Tue Jul 16 2024 Atlantic ridging will remain across the Florida Peninsula through the duration of the forecast. This will result in gentle to moderate east to southeasterly breezes across Keys waters. Winds will tend to surge in the evening and night hours and lull during the day. && .AVIATION... (18Z TAFS) Issued at 259 PM EDT Tue Jul 16 2024 VFR conditions will prevail at EYW and MTH through the TAF period with easterly to southeasterly winds near 10 knots. Isolated showers and thunderstorms in the vicinity of the Lower Keys will continue over the next few hours, so the VCSH will remain in the TAFs until at least 22Z, and any activity that looks to move over either terminal will have short term amendments issued appropriately. && .PRELIMINARY POINT TEMPS/POPS... Key West 83 90 83 90 / 10 20 30 30 Marathon 83 91 82 91 / 10 20 30 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...LIW Aviation/Nowcasts....DP Data Acquisition.....DR Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest