Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
453 FXUS62 KKEY 011900 AFDKEY Area Forecast Discussion National Weather Service Key West FL 300 PM EDT Sat Jun 1 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 300 PM EDT Sat Jun 1 2024 KBYX radar has remained quiet for much of the day. However, within the past hour, a shower has developed near Biscayne Bay south of Miami. This shower was moving to the southwest to west at 5 to 10 knots. GOES 16 Visible satellite imagery shows mostly fair weather cumulus throughout the Florida Keys with any stratocumulus confined to the Upper Keys closer to the shower. Temperatures along the Island Chain are in the upper 80s to near 90 degrees with the Big Pine Key RAWS coming in with 92 degrees. Dew points are in the lower 70s as the modified continental air mass remains over the area. Strong surface high pressure just off the North Carolina coastline is dominating the pattern across much of the Southeastern United States, including Florida. As a result, marine platforms are observing northeast to east winds of 15 to 20 knots with Island Chain communities observing 15 to 20 mph. .FORECAST... The aforementioned surface high pressure continues to drive farther southeast into the Atlantic over the next couple of days. As a result, expect fresh breezes to continue through this evening before gradually relaxing through the remainder of the weekend and into early next week. Regarding rain chances, mid and upper level troughing deepens slightly across the area with weak shortwaves/perturbations moving through the flow. The upper trough will be accompanied by a 70 knot jet streak placing the Keys in the left exit region of this jet for the next several time periods as it slowly traverses eastward through early next week. Therefore, expecting an uptick in convective activity beginning tonight across the Keys. Due to this, increased PoPs tonight to 40% from 30% and also increased Sunday through Monday from 40% to 50%. Model guidance is also showing instability on the rise for the next few forecast periods. We decided to keep tonight slight chances for thunder but decided to increase Sunday through Monday to chances of thunder. With the mid to upper level support and attendant jet streak, hi-res guidance is hinting at these showers and thunderstorms potentially having a fair bit of wind energy with them and therefore, some of the showers and thunderstorms could have strong gusty winds where they occur. Also, while we had cloud lines today, conditions become a bit more favorable for Sunday especially with the increasing moisture. After Monday, we lose the upper level trough with zonal flow commencing for Monday night through mid week, though, mid level troughing remains along with low level moisture. Therefore, based on this, chance PoPs were maintained. For late week into the first half of next weekend, model guidance is differing mainly on the timing of features in the upper levels. Model guidance seems to be honing in on a closed upper level low developing somewhere in the vicinity of northern to central Florida while it moves northeastward. With lingering moisture and mid to upper troughing remaining, chance PoP were maintained through this period. && .MARINE... Issued at 300 PM EDT Sat Jun 1 2024 Winds are expected to surge across much of the Keys late this afternoon continuing through 11 PM this evening before gradually subsiding. As a result, a Small Craft Advisory is back in effect for all the Florida Keys coastal waters until 11 PM EDT. From synopsis, high pressure just off the eastern North Carolina coastline will continue moving farther southeast into the western North Atlantic tonight. This will result in moderate to fresh northeast to east breezes. The aforementioned high sets up over the western North Atlantic for Sunday through the middle of next week while slowly weakening. This will result in gentle to moderate breezes peaking in the afternoon and evenings and lulling overnight into the morning hours. Breezes will further slacken towards late week as the high continues to loosen its grip. && .AVIATION... (18Z TAFS) Issued at 300 PM EDT Sat Jun 1 2024 Through 02/18Z, prevailing VFR conditions are expected at both EYW and MTH. Scattered rain showers with moderate to heavy precipitation may develop after 02/00Z and move within the vicinity of either MTH or EYW. An isolated thunderstorm is not out of the question. However, chances of sub-VFR conditions are too low for inclusion in the TAFs. Cell motions likely would be from 065/15KT. && .CLIMATE... On this day in day in Keys Weather History, the daily record low of 65F was measured at Marathon in 1955. This measurement tied for the coldest temperature ever recorded in the month of June. Temperature records at Marathon date back to 1951. && .PRELIMINARY POINT TEMPS/POPS... Key West 88 80 88 80 / 20 30 50 50 Marathon 87 80 88 80 / 20 40 50 50 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...Small Craft Advisory until 11 PM EDT this evening for GMZ031>035- 042>044-052>055-072>075. && $$ Public/Marine/Fire...MJV Aviation/Nowcasts....Kasper 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