815 FXUS62 KTBW 202357 AFDTBW Area Forecast Discussion National Weather Service Tampa Bay Ruskin FL 657 PM EST Tue Dec 20 2016 .AVIATION... Low clouds associated with a stationary frontal boundary stretched across the peninsula will bring MVFR CIG conditions for most of the night. Some brief IFR conditions could happen overnight into the early morning hours. Some patchy BR is also possible at all terminals between 09-12Z. Winds will be out of the northeast at 5-10 knots through the period. && .Prev Discussion... /issued 202 PM EST Tue Dec 20 2016/ SYNOPSIS... Aloft - A broad low was across Baffin Island Canada and a short wave trough over Ontario and the upper Great Lakes troughed south over much of the eastern U.S. Ridging stretched from Mexico to FL. Surface - A low was in southern Ontario while high pressure sprawled diagonally across the nation from the southern plains to Atlantic waters east of New England. A diffuse and nearly stalled frontal boundary was across FL...from Sarasota Bay to Cape Canaveral and stretched over the adjacent waters. SHORT TERM (Today and Wednesday)... The short wave trough slides east to the Gulf of Saint Lawrence with the associated troughiness exiting the eastern seaboard as the Gulf of Mexico ridge builds back over Mexico...with flow aloft the area backing from nearly zonal to more west- northwesterly. The surface high pressure tracks to the eastern states from FL to NY while the frontal boundary continues to creep south...across southern FL Wed then exiting the state at days end. The developing northwest flow aloft along with the surface high moving east will eventually push the decaying boundary south and out of the area by late day Wed. However...until then the front will have enough energy along with ample moisture to support a few showers in the far south and southeast this afternoon. Slightly drier air works in behind the front with slow clearing for Wed... but for tonight there will be considerable cloudiness...along with patchy fog generally south of the I-4 corridor. Temperatures tonight will cool some but remain above normal...the highs Wed will be near normal. LONG TERM (Wednesday Night - Tuesday)... Surface high pressure along the mid Atlantic coast extending southwest into the northern Gulf region will provide tranquil dry weather across the entire forecast area Wednesday night through early Thursday. On Thursday another cold front will approach from the west with this front then weakening as it sags south through the forecast area during Thursday night and early Friday. Lack of sufficient moisture accompanying the front should result in a dry frontal passage with winds veering around to the northeast and east in its wake on Friday as strong surface high pressure builds toward the mid Atlantic coast. During the upcoming holiday weekend and into early next week models continue to show strong upper level ridging (591 DM) developing over the area in response to an amplifying upper level trough out west. The building upper ridge and increasing large scale subsidence associated with it should suppress rain chances with unseasonably warm and muggy conditions expected. Temperatures at the start of the period will be closer to normal compared to what they have been, but will still be running around 5 degrees above normal. Then during the upcoming holiday weekend temperatures are expected to climb to some 10 to 15 degrees above normal as strong upper level ridging builds in over the region with overnight lows in the 60s area-wide, with daytime highs reaching into the lower and middle 80s each afternoon. AVIATION... 20/19Z-21/18Z. A weak front continues to ease south with north and northeast winds and abundant low level moisture. This morning/s IFR to LIFR is giving way to MVFR with LCL IFR...mainly CIGS...for this afternoon and evening. Anticipate conditions to deteriorate AFT midnight with BKN-OVC low stratus and some patchy BR. These will prevail through sunrise then begin to lift mid-morning. MARINE... A weak front creeps south of the waters and exits late day Wed as high pressure builds in with a slightly drier north and northeast winds..reducing the threat of sea fog. A second front moves through late Thu-early Fri...maintaining north to northeast winds. High pressure builds in behind this second front then moves out over the Atlantic for the weekend with winds becoming easterly. Winds and seas generally look to remain below headline criteria although there may be a few nocturnal wind surges. FIRE WEATHER... Ample low level moisture will continue across the area as a weak front creeps southward and exits the area late Wed. Northerly to northeasterly flow fills in behind the front and will be reinforced by a second front late Thu-early Fri...maintaining a slightly cooler and drier air mass. However temperatures hover near normal and the RH stays above critical levels. High pressure moves out over the Atlantic for the weekend with winds becoming easterly.. allowing more moisture to return. && .Preliminary Point Temps/PoPs... TPA 61 73 60 76 / 0 0 0 0 FMY 65 78 62 80 / 10 0 0 0 GIF 60 73 57 77 / 0 0 0 0 SRQ 63 74 60 76 / 0 0 0 0 BKV 56 71 52 76 / 10 0 0 0 SPG 62 72 61 74 / 0 0 0 0 && .TBW WATCHES/WARNINGS/ADVISORIES... FL...None. Gulf waters...None. && $$ AVIATION...74/Wynn