000 FXUS62 KKEY 060919 AFDKEY Area Forecast Discussion National Weather Service Key West FL 419 AM EST Mon Feb 6 2023 ...New DISCUSSION, MARINE, AVIATION... .DISCUSSION... Issued at 418 AM EST Mon Feb 6 2023 Lower to mid tropospheric flow above the immediate surface has become westerly as a southern stream shortwave progresses quickly off the southeast United States, escorting an interesting convectively- enhanced low pressure system rapidly northeast well offshore. Near the surface, it was difficult to discern much of a trough except for the discrepancy between near 70F dew points over the Keys versus lower 60s dew points over south mainland Florida. Water vapor imagery shows the apex of the cyclonic curvature of the upper trough continuing to push southeast over the eastern Straits, with precipitable water values just above 1.3 inches per GOES16 estimates. A shallow cyclonic feature in the 850-700 mb layer was holding position in the eastern Gulf, likely preventing any advancement of the sub-one inch precipitable water values any closer to the Keys. A few showers were noted in the Straits not too far offshore the reef, rooted on southward- drifting boundaries. Today through Wednesday, mid level ridging will slide east across the Gulf as a northern stream trough moves offshore the Mid Atlantic states, and low level ridging builds across the eastern seaboard, then southeast offshore Georgia and South Carolina. This will allow for a period of breezy easterly winds. The lower tropospheric moisture depth varies among the short term guidance, with the most likely location for a few showers to be the Straits, and especially along any convergence zones setting up north of western Cuba. The mid level heights rise only slightly beyond late tonight over the Keys, with dry air dominating throughout the 700-200 mb layer. Instability actually builds a bit over the western Straits by Tuesday and Wednesday nights. While good mixing by day and the nearby continental airmass appears to entrain over the Keys proper, this could leave to a thunderstorm or two well southwest of Key West over the Straits during the night. While in the gridded forecasts, the coverage would be too limited to warrant general thunder mention in the coastal waters text forecasts at this time. Breezy conditions will abate somewh Thursday through Friday as low level ridging moves east while another progressive trough moves into the central U.S. Patchy deeper moisture begins to head northwest around the mid level ridge by Wednesday night, thus slight chances for rain resume for the Keys forecasts. The next front appears to approach late Friday. Guidance is attempting to reach greater agreement, although the GFS slightly slower and slightly less enhanced with the northerly wind surge, at least during the Friday night portion. As usual, there is a pretty good spread in the ensemble MOS guidance concerning how near or below normal temperatures may briefly get, but the concensus remains in drier, breezy first half to two thirds of the weekend. And, as before, quick progression of the following high means guick moderation with moisture left by the stalling trough lurking not too far to the south for early next week. && .MARINE... Issued at 418 AM EST Mon Feb 6 2023 No watches, warnings, or advisories are in effect for the Florida Keys coastal waters at this time. However, Small Craft Advisories may be required tonight for portions of the Straits of Florida and Hawk Channel. High pressure will build across the eastern United States, resulting in freshening northeast to east breezes this evening. Fresh to strong easterly breezes will continue through the middle of the week as the high pressure builds into the western North Atlantic and offshore the southeast United States. Winds will turn out of the southeast and slowly decrease Thursday and Thursday night as the high pressure moves further east. A cold front will approach the Florida Keys and adjoining coastal waters late Friday. && .AVIATION... (06Z TAFS) Issued at 418 AM EST Mon Feb 6 2023 VFR conditions will prevail at both EYW and MTH through the TAF period, but there may be brief instances of MVFR ceilings early this morning. Surface winds will be light and generally north to northeast this morning, then will begin to increase during the day and veer to the northeast to east by this evening. && .CLIMATE... On this day in 2009, both the daily record cold high temperature (64F) and the record low temperature (49F) were recorded in Marathon. Temperature records in February date back to 1951. && .PRELIMINARY POINT TEMPS/POPS... Key West 80 72 80 72 / 10 10 10 0 Marathon 81 72 81 72 / 10 10 0 0 && .KEY WATCHES/WARNINGS/ADVISORIES... FL...None. GM...None. && $$ Public/Marine/Fire...JR Aviation/Nowcasts....NB Visit us on the web at weather.gov/key Follow us on Facebook and Twitter at: www.facebook.com/nwskeywest www.twitter.com/nwskeywest