Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
872 FXUS62 KKEY 131945 AFDKEY Area Forecast Discussion National Weather Service Key West FL 345 PM EDT Thu Jun 13 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 330 PM EDT Thu Jun 13 2024 After very quiet daytime hours yet again today, recent KBYX radar returns suggest things are quickly changing. Showers and thunderstorms are approaching our western coastal waters, with additional activity to the east. It is a bit interesting that convection has struggled to fire over Cuba today, despite ample deep, tropical moisture sampled in the CIMSS satellite-derived total precipitable water product. Temperatures are generally in the mid to upper 80s across the island chain, with dew points in the upper 70s. For tonight, all available mesoscale numerical weather prediction guidance suggests the convection west of our coastal waters will sag southeastward this evening. Widespread showers are expected to continue through much of the overnight hours, with heavy rainfall being the primary threat. A Flood Watch remains in effect for the entire Florida Keys island chain through the overnight period. The stationary front that has remained draped across the Florida Peninsula for much of the week will remain in place for at least 24 more hours. With a conveyor belt of deep, tropical moisture continuing, bouts of unsettled weather should continue through tomorrow, before drier air finally begins to filter across the Keys for late Friday night through the weekend. The front will be replaced by a modified continental high that will slide from the Mid-Atlantic eastward to the western Atlantic for late in the weekend through early next week. Winds will clock around to the east and freshen, with an extended period of breezy conditions expected for this period. Rainfall will be dictated by any moisture undulations in the easterlies, although in this freshened flow, at least low-end chance levels of measurable rainfall can be expected for most periods, especially in the eastern island communities and marine zones. There is global numerical weather prediction ensemble support to suggest a tropical wave may push towards the Keys coastal waters by the middle to latter part of next week, which may result in an uptick in rainfall late in the forecast period. With increased sunshine expected for the weekend through much of next week, temperatures should moderate to near normal, with highs near 90F, and lows in the lower 80s. & .MARINE... Issued at 330 PM EDT Thu Jun 13 2024 Small Craft Should Exercise Caution headlines posted for the western marine zones south of the Lower Keys, including western Hawk Channel and the western Straits of Florida. Scattered showers and thunderstorms are expected to increase in coverage and intensity over the next several hours. Heavy rainfall, gusty winds and confused seas, and cloud to surface lightning strikes will be possible with any stronger storm. From synopsis, the pattern for the remainder of the week will feature weak high pressure over the western North Atlantic and a frontal boundary stalled over northern Florida. However, the main weather maker will be a large cyclonic system centered over Central America. Mainly moderate breezes and an extended period of unsettled weather featuring thundery squalls will persist tonight through Friday night. Rain and thunder chances will decrease gradually starting Saturday. Breezes will freshen by Sunday night, with moderate to fresh easterly breezes expected for late in the weekend into early next week. && .AVIATION... (18Z TAFS) Issued at 330 PM EDT Thu Jun 13 2024 VFR conditions will mainly prevail through approximately 22Z, but showers and thunderstorms similar to yesterday will approach both terminals and push through during the late afternoon and evening hours. Intermittent periods of MVFR or even IFR conditions are possible due to fluctuations in CIGs and VIS. VCSH is in the forecast at 22Z, and changes over to VCTS at 22Z, but there are still no TEMPO groups for category changes due to uncertainty with respect to timing. Near-surface winds will overall remain southerly, but become variable when the showers and thunderstorms move through. && .PRELIMINARY POINT TEMPS/POPS... Key West 77 88 79 90 / 80 70 50 40 Marathon 77 88 79 89 / 80 70 50 40 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...Flood Watch through late tonight for FLZ076>078. GM...Small Craft Advisory until 5 PM EDT this afternoon for GMZ044- 054-055-074-075. && $$ Public/Marine/Fire...BT Aviation/Nowcasts....DP Data Acquisition.....11 Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest