Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
508 FXUS62 KKEY 140832 AFDKEY Area Forecast Discussion National Weather Service Key West FL 432 AM EDT Mon Jul 14 2025 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 430 AM EDT Mon Jul 14 2025 KBYX radar has been active overnight. Multiple mesoscale boundaries continue to meander about the Florida Keys. These boundaries have been responsible for waxing and waning isolated showers and thunderstorms throughout the overnight hours. Most of the activity has remained out over the Straits of Florida with the most recent activity being a fairly robust thunderstorm which developed right over Big Pine Key and No Name Key. This cell prompted a Marine Weather Statement for wind gusts to near 30 knots through around 400 am earlier this morning. GOES East Nighttime Microphysics imagery shows cumulus congestus clouds along with some high level cirrus throughout the area. The only cumulonimbus is associated with the thunderstorm over Big Pine Key. MRMS data shows estimated rainfall amounts of a half to one inch for Big Pine Key. Temperatures along the Island Chain are in the lower 80s with dew points in the mid to upper 70s. However, Big Pine Key has dropped to a cool 72 degrees with a dew point of 67 degrees as a result of a thunderstorm that recently affected the area. High pressure remains over the area with low pressure centered off the north Florida/Georgia coastline. The pressure gradient between these two systems is actually rather weak with only a few millibars separating high and low pressure. Due to this, marine platforms around the Keys are observing mainly variable breezes of 5 knots or less, especially outside of any convection. Island Chain communities are also observing variable breezes of near 5 mph or less. .FORECAST... Today through Wednesday, the focus will mainly be on the 30% area for tropical development within the next 7 days that the NHC- National Hurricane Center has highlighted across the northern Gulf. At most, a weak area of low pressure is expected to continue meandering slowly southward from off the Georgia coastline and then retrograde back to the west through mid week. As a result, bouts of showers and thunderstorms are expected to be initiated each day as the system slowly moves through the area. Most of the activity the Keys could see may initially form on the mainland and then drift southward through the Keys. Any storms will be capable of producing strong gusty winds, locally heavy rainfall, and frequent lightning. The forecast was split for the today period for the Upper Keys (70%) and then the Middle and Lower Keys (50%). Confidence remains higher in the Upper Keys being the more favorable region for showers and thunderstorms today as storms roll off the mainland. As we progress into tonight, the chance for rain goes up to about the same everywhere with 70% for the Island Chain. The Weather Prediction Center (WPC) has the Keys highlighted in a marginal risk (Level 1 out of 4) for the today through Tuesday time period. A more typical summer time pattern returns for the second half of the week and into the weekend. High pressure over the Atlantic builds into Florida bringing a return to the east to southeasterlies and moisture undulations around the western periphery of the high. As a result, expect decreasing rain chances with 40% for Wednesday night and Thursday before rain chances return to around normal for the remainder of the extended which is near 30%. Also, it will for sure be summer with highs in the lower 90s and overnight lows in the lower 80s. Heat index values are expected to range from 102-107 degrees through this period which is just under Heat Advisory criteria. We will continue to monitor. && .MARINE... Issued at 430 AM EDT Mon Jul 14 2025 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, weak low pressure tries to develop in the vicinity of Florida heading through the first half of the week. Initially, the Keys will be on the southern fringe in a col region resulting in mainly variable breezes through tonight. As the weak low pressure area shifts to the west and high pressure builds in behind, breezes will freshen becoming southeast to south at first, before becoming east to southeast for mid to late week. Also, expect increasing coverage of showers and thunderstorms through the middle part of the week. && .AVIATION... (06Z TAFS) Issued at 430 AM EDT Mon Jul 14 2025 VFR conditions are expected to largely prevail at EYW and MTH through the TAF period. The exception will be the likelihood of passing showers and thunderstorms throughout the day producing MVFR or lower conditions , though timing and coverage carries enough uncertainty to leave mention of this for later TAF amendments and routine issuances. Winds will remain variable at near 5 knots. Higher gusts will be possible with passing shower and thunderstorm activity. && .CLIMATE... On this day in 2023, the daily record high temperature of 98F and the daily record warm low temperature of 86F were recorded at Marathon. Temperature records for Marathon date back to 1950. && .PRELIMINARY POINT TEMPS/POPS... Key West 88 78 85 80 / 50 70 80 60 Marathon 90 76 86 80 / 50 70 80 60 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....MC Data Acquisition.....MC Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest