Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
635 FXUS62 KKEY 030227 AFDKEY Area Forecast Discussion National Weather Service Key West FL 1027 PM EDT Sun Jun 2 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 1027 PM EDT Sun Jun 2 2024 It has been a busy late afternoon into evening across the Florida Keys. An outflow boundary worked its way westward from the Upper Keys to the Lower Keys and is now moving across the offshore Gulf waters near the Dry Tortugas and across the western Straits of Florida. This outflow boundary was responsible for developing convection along it bringing a thunderstorm to Marathon earlier this afternoon around 4-430 pm ish. This same boundary pushed further westward and sparked new thunderstorms in the vicinity of Key West which prompted a Special Marine Warning for wind gusts exceeding 34 knots just outside the harbor. In Key West Harbor, wind gusts to near 30 knots were realized and a Marine Weather Statement was issued for the storm. Most of the activity late this afternoon and this evening has been very pulsey in nature. This means that from the time a tower started to go up to the time it diminished averaged between 30-45 minutes which is typical especially as we get further into the rainy season here in the Florida Keys. A very summer-like evening for sure. With the recent rain in Key West, temperatures are in the mid to upper 70s with the remainder of the Keys having rebounded to near 80 degrees. Surface high pressure off the Carolina coast continues to move further out into the Atlantic this evening. As a result, marine platforms around the Keys are observing east breezes of 10 to 15 knots with Island Chain communities observing near 10 mph. .SHORT TERM FORECAST... It is no surprise the 00z evening sounding is very moist especially from approximately 935 mb up to 760 mb with slight drying above this layer. However, the main theme is a very moist sounding. There were showers nearby so the sounding most likely went through the cloud associated with the earlier activity. CAPE value measured was near 1500 J/kg which is sufficient to support thunderstorms. Also, the PWAT value measured was 2.26 inches indicative of a very moist atmosphere over the Keys. Wind profile shows mainly east winds with slight veering to the east-southeast. Also, we have troughing at both the mid to upper levels. The upper level trough was also accompanied by a 50-60 knot jet streak which is finally a trigger to help provide some lift in the atmosphere to get storms. The outflow boundary moving westward at the surface also helped to spark the convection as well. All in all, the ingredients came together to support an active late afternoon and evening across the Keys. Going through the overnight, residual moisture remains along with convective outflow boundaries which could spark new activity at any point in time. We have seen this already in the Upper Keys where new showers formed. Therefore, no change expected to the ongoing forecast. && .MARINE... Issued at 1027 PM EDT Sun Jun 2 2024 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, high pressure off the Carolina coast will weaken as it lengthens eastward into the Atlantic over the next few days. As a result mostly easterly breezes will range gentle to moderate, peaking in the afternoon and evenings and lulling overnight into the morning hours. Above normal rain and thunder chances will persist through at least Monday night. && .AVIATION... (00Z TAFS) Issued at 1027 PM EDT Sun Jun 2 2024 VFR conditions are generally expected for both EYW and MTH terminals through the overnight period and into the morning hours on Monday. With the atmosphere largely worked over from this evenings convection, current thinking is the overnight will remain quiet resulting in VCSH being pushed back into the morning hours on Monday. Any shower or thunderstorm that moves over the terminal will result in MVFR conditions for CIGs and VIS with the potential for IFR in the heaviest activity, mainly for VIS. Near surface winds will be out of the east to southeast at 12 to 15 knots through the overnight with 8 to 12 knots for much of Monday. In and near convection, winds may gust higher. && .PRELIMINARY POINT TEMPS/POPS... Key West 82 90 82 90 / 50 50 40 30 Marathon 82 90 82 90 / 50 50 40 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MJV Data Acquisition.....DP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest