Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
879 FXUS62 KKEY 071851 AFDKEY Area Forecast Discussion National Weather Service Key West FL 251 PM EDT Fri Jun 7 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 251 PM EDT Fri Jun 7 2024 Southerly flow has helped keep convective activity muted across the Florida Keys forecast area this afternoon. Cloud streamers north of the Lower Keys have attempted to develop showers, but have really struggled and puttered out quickly. GOES Visible Satellite is highlighting a reverse cloud attempting to develop along the Lower Keys. The VWP is noting the shift in the steering flow direction to more southwesterly, so this could finally be the trigger that is necessary for at least some convection along the island chain this afternoon. The close proximity of an upper-level shortwave over the northeastern Gulf has helped produce a plethora of lightning strikes over the Mainland, so if a thunderstorm does develop, occasional to frequent lightning strikes are not out of the question. Temperatures have climbed into to near 90 degrees in most island communities, making for a toasty afternoon. The shortwave trough over the northeastern Gulf will gradually drive southeastwards and elongate across Florida and the Bahamas through tomorrow. This will keep some upper-level support available for our area, so have kept chance lightning through tomorrow morning. As of this afternoon, our atmosphere has remained mostly untapped. Have decided to nudge PoPs up for tonight to 50% as our steering flow looks to return to the south, which could potentially bring Cuban convective or outflow across the Straits and island chain. Ample moisture will remain in place across the region through Saturday, however, some drier air will filter into the region as a mid level ridge builds across the Gulf. At the surface, light to gentle southerly winds will prevail through Sunday night. Southerly flow is not generally a favorable direction for shower and thunderstorm development, so we could see PoPs drop more in the upcoming forecast cycles. Mesoscale processes would be the dominant forcing mechanism for any showers or thunderstorms that develop for a majority of the weekend. Looking ahead into next week. the forecast becomes very murky in terms of both rain/thunder chances and winds. The overall synoptic set-up between models show some agreement, but that is about as far as the agreement goes. Ensemble guidance brings an upper-level trough across the Southeast next week, which will begin to pull high moisture content up from the western Caribbean beginning Tuesday, with the best moisture moving across the Keys around Wednesday night into Thursday morning. The ECMWF keeps the moisture plume to our west and rain chances a little more muted. Meanwhile, the GFS brings the deep tropical moisture directly over the Keys. How far east this moisture makes it will likely be dependent on the strength and location of of a mean layer ridge in the western North Atlantic. If the GFS scenario plays out, we could see a few days of unsettled weather and potentially heavy rainfall. Have held onto high chance PoPs and chance thunder Monday through the extended forecast due to the high uncertainty regarding the forecast. We will continue to monitor forecast trends and update as necessary each forecast cycle. Stay tuned. && .MARINE... Issued at 251 PM EDT Fri Jun 7 2024 There are no watches, warnings, or advisories in effect for the Florida Keys coastal waters. From synopsis, weak high pressure over the central North Atlantic will slide further eastward through the weekend as a frontal boundary stalls off the Eastern Seaboard and over north Florida. This will result in light to gentle southerly breezes across the Keys coastal waters through Monday. Southeast to south breezes will likely become gentle to moderate early next week. && .AVIATION... (18Z TAFS) Issued at 251 PM EDT Fri Jun 7 2024 VFR conditions will prevail at both EYW and MTH through the TAF period. Going into this evening it is possible that some showers or thunderstorms could spark up, but for the time being VCSH is included at EYW but if confidence increases then the TAFs will be updated. Near surface winds are southwest to south at 5 to 10 knots. && .CLIMATE... On this day in 2017, the daily record rainfall at Key West (4.39") and Marathon (4.24") were both recorded. Rainfall records date back to 1871 in Key West and 1950 in Marathon. && .PRELIMINARY POINT TEMPS/POPS... Key West 81 89 81 90 / 50 40 40 40 Marathon 81 89 82 90 / 50 40 40 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...NB Aviation/Nowcasts....AP 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