Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
860 FXUS62 KKEY 301904 AFDKEY Area Forecast Discussion National Weather Service Key West FL 304 PM EDT Sun Jun 30 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 300 PM EDT Sun Jun 30 3004 It has been a fairly wet day across the Florida Keys to end June. KBYX radar has been active all day with numerous showers and scattered thunderstorms ongoing much of the day. The stratiform rain that held its grip across the Lower and Middle Keys has finally dissipated this afternoon, though, scattered showers and thunderstorms continue to wax and wane. Due to the vast amount of cloud cover today, temperatures have been held in check along the Island Chain when compared to this time yesterday with temperatures in the lower to mid 80s. Dew points are also a little lower when compared to this time yesterday in the mid 70s. Marine platforms are observing chaotic wind speeds due to the convective influences, but direction is mostly northeast to east. .FORECAST... The forecast for the next week can be broken down into 3 distinct periods. The first one being tonight and Monday. An upper level disturbance continues to propagate southwestward across the southern Florida Peninsula through this time frame. As a result, we have the 3 ingredients needed to support showers and thunderstorms. We have the tropical moisture, lifting mechanism, and the instability. Therefore, the previous forecast was largely kept due to the high confidence. The previous 50% was held for tonight with 60% for Monday. The only change was to go with chance thunder for tonight and Monday since statistical guidance had fairly high thunder probabilities along with the strong upper level disturbance moving through. Any showers and storms will be capable of gusty winds, potentially strong, and frequent lightning at times along with heavy rain. The next period is Monday night through Tuesday night where ridging will be the dominant feature again. The only caveat to this will be potentially some weak shortwaves in the upper flow that may touch off an increased period of showers and storms. However, there is too much uncertainty in terms of timing and exact placement to warrant higher PoPs during this time frame, therefore, maintained the 30%. Also, with sunnier conditions returning, expect a return to much warmer temperatures again with highs in the lower 90s Tuesday. Right now, it appears dew points will remain low enough to not warrant heat advisories but we will keep an eye on this. Wednesday through next weekend, the main story will be Beryl (major hurricane) passing by well to the south of the Florida Keys as per the latest National Hurricane Center (NHC) track. However, the subtropical high over the Atlantic and Beryl passing by to the south may result in an increase in winds for a time across the Keys but for now it looks to remain below breezy conditions for the Island Chain. There still remains uncertainty as to exactly how much moisture will move through the Keys in association with Beryl but the most likely time period would be Wednesday through Thursday where we may see an increase in showers and thunderstorms but still too early to tell. At the very least, we expect Wednesday through next weekend to feature near normal rain chances (~25%) and highs in the lower 90s with lows in the lower to mid 80s. Dew points look to remain low enough right now to not warrant heat advisories but we will keep an eye on this. && .MARINE... Issued at 300 PM EDT Sun Jun 30 3004 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, an area of low pressure located in the southwestern part of the Bay of Campeche moves inland tonight and dissipates. The western periphery of the subtropical high over the Atlantic will maintain modest control over the Keys. This will result in mainly gentle to moderate breezes over the next few days, occasionally light to gentle. Tuesday through late week, breezes will freshen as the gradient between the subtropical high over the Atlantic and Beryl (major hurricane) strengthens. Beryl is expected to remain well south of the Florida Keys as it marches west northwest through the Caribbean Sea. Please review the Tropical Cyclone Advisories for additional information on the track and future evolution of Beryl. && .AVIATION... (18Z TAFS) Issued at 300 PM EDT Sun Jun 30 3004 Scattered showers and isolated thunderstorms will wax and wane in the vicinity of the terminals through 18z Monday. Bouts of sub- VFR ceilings and visibilities will be possible as this activity pushes through, along with gusty winds. There will likely be extended bouts of VFR conditions as well, but timing prediction for sub-VFR conditions warrants leaving out impacts for now. Radar will be monitored to potentially rapid storm development, with TEMPOs and amendments to be issued as needed. Outside of any storm, near- surface winds will remain out of the east less than 10 knots. && .PRELIMINARY POINT TEMPS/POPS... Key West 81 89 82 91 / 50 60 40 20 Marathon 81 89 83 91 / 50 60 40 30 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....BT Data Acquisition.....JAM Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest