113 FXAK67 PAJK 172332 AFDAJK Southeast Alaska Forecast Discussion National Weather Service Juneau AK 232 PM AKST Thu Jan 17 2019 .SHORT TERM.../Through Saturday/ Complex pattern aloft will make for a tricky forecast, especially Fri night and Sat. Upper trof will remain across NW Canada and E interior AK. Several shortwaves will move N through SE AK and the eastern gulf during the period. First main shortwave will move N into the southern area Fri, then reach the N Fri night while weakening. Another shortwave will move N into the southern area Sat. At the surface, high pressure will remain over NW Canada, while a series of fronts move N into the area. An occluded front will move N into the S area Fri, then reach the N and weaken there Fri night. A low will move NNE to the central BC coast Sat, with its associated occluded front moving into the S Sat morning. Models have been struggling with the second system, but seem to be honing in on the low track. Main forecast issues will be how long any leftover fog will last, how far N precip gets with the various systems, and winds. Areal coverage of the fog has decreased quite a bit today with the increased offshore flow drying things out. Still a little fog around Yakutat, and some spotty fog over the more sheltered parts of the inner channels. Offshore flow will continue to increase, with drier air being advected in. Also, clouds will move in from the S tonight, so expect much of the remaining fog to dissipate or freeze out this evening. The place that might hang onto fog longest is around Yakutat, as higher level clouds will stay S of there for the most part, and outflow will take longer to become established. As for precip potential, precip should move into the far S late tonight or early Fri morning ahead of the first front. Models suggest this front will remain strong enough for some of the precip to reach the N by Fri evening, enhanced by a little overrunning and deformation aloft. Could see a couple inches of snow out of this front over the central area and parts of the N Fri afternoon and night. The S may start as snow or a mix but should become mainly rain by Fri afternoon as warmer air moves in. Approach of second front and low will increase offshore flow over the N, so the leftover frontal band there should dissipate early Sat morning, and end any remaining snow associated with it. More precip should reach the S Sat morning, with it being mainly rain. Winds will be increasing some tonight as pressure gradient increases between the NW Canada high and front approaching from the S. Gales will continue in Lynn Canal, with SCA level winds over much of the remaining northern inner channels. Keeping strong winds going for Skagway through Fri as colder air will continue to filter in. In the Juneau area, still some weak mtn wave activity downtown, but this will likely diminish late tonight. Keeping strong winds there through tonight. Offshore winds across the central and S will increase some Sat as low and second front move in. .LONG TERM.../Saturday night through Wednesday, as of 10 PM Wednesday/ While the weekend continues to draw nearer, the forecast continues to remain uncertain. Extreme shifts in Saturday's low track continue with each new model guidance provided. Synoptically, the period begins with 3 upper level low pressure systems interacting with each other, the strongest of which sits the border between northern Alaska and the northern Yukon, and it will likely act to direct weather systems further south from southeast Alaska's perspective. The other two upper lows remain over the the northern Pacific. This leaves multiple surface lows and fronts scattered over the southern gulf and northern Pacific as well as a forecast situation. Precipitation has trended further south. This drastically lowered the snow amounts over the northern Panhandle as a whole. Additionally with the more southern low track now favored in the forecast gales are no longer expected over the Gulf. Sunday the surface front driven by the more western upper low over the northern Pacific looks to come ashore. Ultimately, wind will not be very impactful Sunday; however, snow potential will still exist briefly for the northern Panhandle before the warmup likely begins. Monday through midweek, continues to look quite wet and active; however, this will also mark a shift into a much warmer weather pattern with highs pushing well above freezing by the middle of the week for the vast majority of the Panhandle. Forecast confidence is below average for the weekend and adjustments are likely. Ensemble means and the NBM continue to act as the primary guidance of the extended forecast. Fortunately, next week shows much clearer signatures allowing for higher confidence Monday into mid- week. && .AJK Watches/Warnings/Advisories... PUBLIC...Strong Wind through late tonight for AKZ025. Strong Wind through Friday afternoon for AKZ018. MARINE...Gale Warning for PKZ012-013. Small Craft Advisory for PKZ021-022-031-032-036-041-042. Small Craft Advisory due to Seas for PKZ043-051. && $$ RWT/JB Visit us at http://www.weather.gov/Juneau