Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
107 FXUS62 KKEY 161903 AFDKEY Area Forecast Discussion National Weather Service Key West FL 303 PM EDT Sun Jun 16 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 302 PM EDT Sun Jun 16 2024 KBYX radar shows a couple showers across the westernmost Straits of Florida to the southwest of Rebecca Shoal Light. These showers most likely formed along a speed convergence boundary. GOES 16 Visible satellite imagery shows some high cirrus streaming from west to east across the Keys with mainly cumulus and stratocumulus streaming from east to west. Temperatures along the Island Chain are in the upper 80s to near 90 degrees with dew points in the upper 70s to near 80 degrees. This is resulting in heat indices of 100 to 105 degrees. Strong surface high pressure is centered off the New England coastline and building southward as pressures are falling across the Yucatan Peninsula and the Bay of Campeche. Due to this, marine platforms are observing 15 to 20 knots across the western parts of the reef with 10 to 15 knots for the central and eastern areas of the reef off the Middle and Upper Keys. Island Chain communities of the Middle to Lower Keys are observing 15 to 20 mph with the Upper Keys 10 to 15 mph. .FORECAST... Strong surface high pressure off the New England coastline is slowly moving farther out into the North Atlantic and building southward as it does so. This is working in combination with pressures falling across the Bay of Campeche and the Yucatan Peninsula resulting in a strengthening pressure gradient across much of the Southeastern United States. This will be the dominant weather feature driving the Keys weather for the next few days. As a result, breezy conditions are expected to continue through mid-week with the Upper Keys waiting until tomorrow to see the uptick in the breezes. Regarding moisture, the tropical moisture plume that has plagued South Florida and the Keys for the past week is continuing to shift northwestward bringing the unsettled weather to Texas and Louisiana. This will result in the aforementioned areas becoming very wet in the days to come and the Keys being in a more typical summer pattern for the next few days. The exception will be tonight where we will remain quite dry. Therefore, PoPs were decreased from 20% to 10% for tonight. Monday through Tuesday night remained unchanged at 30%. The National Hurricane Center has increased (70% chance of development over the next 7 days) the odds of tropical development occurring in the Bay of Campeche in the days to come as a piece of the Central American Gyre breaks off and moves northwestward. Then things get interesting, the latest guidance continues to show a vorticity lobe in the upper levels, originally associated with recent rains across Florida, coming back to the west. Model guidance shows this festering for a little bit over the western North Atlantic to the north of Hispaniola and Puerto Rico. This vort maxima will be waiting on the upper level ridge that will bring the prolonged heat to the Midwest and Northeast to pick this energy up and shift it back to the west. As we know, we have clockwise flow around a high so once this gets picked up it will most likely have only one place to go which continues to remain uncertain at this time. Some guidance brings this feature into the north to central Florida coastline or perhaps even as far north as South Carolina. It is still remains too early as to what this feature will become but the risk is there for tropical moisture to potentially make a reappearance for at least some part of Florida mid to late next week resulting in PoPs being kept at 40%. One thing to also mention is the flow looks to be fast so anything that might try to develop wouldn`t have much time to do so. We will continue to monitor. && .MARINE... Issued at 302 PM EDT Sun Jun 16 2024 Small Craft Advisories are in effect for most of the Florida Keys coastal waters, except for Florida Bay, the Bayside and Gulfside waters to the west end of the Seven Mile Bridge, eastern hawk Channel, and the far eastern Straits of Florida. Small Craft Advisory Likely will be Required Monday afternoon are headlined in the zones without the Small Craft Advisory. From synopsis, strong surface high pressure centered off the New England coast working in tandem with falling pressures over the Yucatan Peninsula and the Bay of Campeche is expected to result in moderate to fresh breezes tonight through mid week. An area of low pressure may develop mid week a few hundred miles north of the central Bahamas near mid week and move towards the north to central Florida coastline. This will result in slackening breezes before high pressure takes control again resulting in freshening east to southeasterly breezes late week. && .AVIATION... (18Z TAFS) Issued at 302 PM EDT Sun Jun 16 2024 VFR conditions will prevail at both island terminals through the TAF period, however, brief intermittent MVFR CIGS are possible through the late afternoon. Easterly surface winds will between 12 to 16 knots, with frequent gusts of 18 to 23 knots. && .CLIMATE... On this day in 1906, a Category One Hurricane moved slowly to the north-northeast crossing what is now the Seven Mile Bridge. Instrumentation in Key West recorded a minimum pressure of 29.62" and a peak wind of 42 mph. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 89 83 89 / 10 20 30 30 Marathon 82 90 82 90 / 10 30 30 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory until 5 AM EDT Monday for GMZ033>035-043- 044-053>055-073>075. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....NB 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