Area Forecast Discussion
Issued by NWS Key West, FL
Issued by NWS Key West, FL
536 FXUS62 KKEY 300811 AFDKEY Area Forecast Discussion National Weather Service Key West FL 411 AM EDT Thu May 30 2024 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 400 AM EDT Thu May 30 2024 Currently - Weak and variable breezes continue this morning due to the persistent lack of any driving force. Currently, the lack of pressure gradient is due to troughing along the Atlantic coast and the Atlantic ridge held off to the east. An associated deep layered trough is marching eastward through the eastern United States and has contributed to the near total break down of the mid and upper level ridge that stretches across our area. Last evenings sounding indicated ample CAPE but some lower level inhibition and drier air. This along with the lack of forcing has been enough to keep shower activity at bay. The weak flow has kept record warmth across the area with highs breaking into the 90s. Thankfully, dew points remain in the lower to mid 70s. Forecast - The overall pressure gradient will remain weak across the Keys today into tomorrow. As a result, winds will remain quite light and often variable. Synoptically speaking, winds will tend easterly. We are already in the season where any hint of troughing aloft usually spells wet. Countering this will be relatively low precipitable water, persistent lower level inhibition, and lack of forcing. With that said, South Florida should light up this afternoon. This along with a northeast to east steering flow may drive this activity and their progeny into our gulf and bay side waters. Another potential convective source will be the development of an island cloud line. While some island locations will have a higher chance of being affected than others, overall the convective chance is expected to remain slight. Continued hot conditions will prevail with day time highs pushing above 90. Dew points will remain in the lower to mid 70s. Guidance has been consistent for awhile now that a high pressure system centered over the Great Lakes will drive southeastward over the next couple of days and off the Mid-Atlantic coast. The unusual path/evolution of this high will sharpen the local pressure gradient. Expect northeast to easterly breezes to freshen considerably Friday afternoon and evening. These breezy conditions will prevail through the weekend. The incoming drier modified continental air will result in dew points dropping, likely below 70. High temperatures will also be pushed down to near normal. In addition, mid and upper level ridging will strengthen and deep layered moisture will remain limited. Overall, rain chances will remain limited at best. By late in the weekend and early next week, the previously mentioned high will elongate out into the Atlantic. The pressure gradient and winds will trend downwards. Expect subtle moistening and warming to take place. However, the steady easterly breezes should help to hold conditions to near or slightly above normal. Rain chances are expected ease upwards to low chance due to increasing low level moisture and a migrating shortwave trough. && .MARINE... Issued at 400 AM EDT Thu May 30 2024 A slack pressure field will persist across Keys waters today. As a result, winds will remain light and, at times, variable. There is the potential that mainland sea breeze convection may move into our gulf side waters late this afternoon and evening. An unusual, for this time of year, Canadian high will spill southeastward off the Atlantic coast over the next few days. As this high pushes out into the Atlantic the local pressure gradient will considerably steepen. As a result the long stretch of slack breezes will finally end. Expect easterly breezes to freshen Friday afternoon and remain so through the weekend. There is a high probability that a caution will be required and advisories cannot be ruled out. && .AVIATION... (06Z TAFS) Issued at 400 AM EDT Thu May 30 2024 VFR conditions will be dominant at both EYW and MTH terminals during the TAF period. Early near surface winds will remain light and variable. In the late afternoon to evening, persistent east- northeasterlies will develop which creates a few uncertainties. A cloud line may develop over EYW if the wind angle is correct, and multiple hi-res models show thunderstorms over South Florida spawning outflow boundaries and showers over the Florida Bay and our gulf side waters and not to far from the terminals by the evening hours. && .CLIMATE... On this day in Keys Weather History, a waterspout moved onshore as an F0 tornado along the north end of Duval Street in 1999. No damage was reported from this tornado. && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...11 Aviation/Nowcasts....AJP Data Acquisition.....AJP Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest