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000 FXAK67 PAJK 272311 AFDAJK Southeast Alaska Forecast Discussion National Weather Service Juneau AK 311 PM AKDT Mon Mar 27 2017 .SHORT TERM...A complex mess of systems will be affecting the area through Tue. A low over the E-central gulf will move NNW and dissipate along the N gulf coast by late this evening. Another low will move NE across Haida Gwaii late tonight, then into central BC Tue. Yet another low will move N into the W gulf Tue. The lows will also have sfc trofs associated with them, mainly on S and E sides. Used blend of the 12z GFS and NAM to handle things through Tue. Main forecast concerns will be precip potential/ptype/amounts and winds. As of 23z...Rain was falling over most of the area, with some snow still reported over the Haines/Chilkat Valley area. As low moves past area to the W tonight, it will sweep a trof through the area and precip should become showery and diminish over the N and central panhandle. The far S will keep some rain going as next low brushes past them to their S overnight and Tue morning. Once this low moves inland Tue afternoon precip should decrease over the S. Over the NE gulf coast, they will be in and out of precip through Tue with multiple lows/trofs affecting them. The snow in the Haines/Chilkat valley area should change to rain as warmer air moves in this evening. Not expecting much more snowfall there...possibly another inch or two. Winds will be strongest near the multitude of lows and trofs. Up to SCA level winds are expected near the main lows and trofs moving through, with most of the stronger winds over the gulf. Will have some 20-25 kt E-SE winds over much of the central and S inner channels until trof moves through this evening. After that, winds on inner channels will be in the 10-20 KT range although the central inner channels may get fairly light overnight and Tue morning with weak pressure gradient there. Otherwise, think central panhandle could get patchy fog overnight as breaks in clouds occur and winds become light. It will be rather short lived though as temps will rapidly warm Tue morning in the late March sun. .LONG TERM.../Tue night through Mon/ Upper level trough over the AK peninsula will finally shift to the northeast while an upper level ridge crosses in to the central AK gulf by Wednesday evening. As the ridge continues to track eastward over the panhandle the next significant low will move just south of the Aleutian chain by Thursday. This upper low will then expand over the western portion of the AK interior by Friday. After that...uncertain on how it will eventually move. At the surface, the low moving up the central gulf will reach Prince William Sound Tuesday evening with the associated front tracking over the eastern gulf and then the panhandle through Wednesday. Gulf winds pick up to max small craft along the front with potential gales. Precip from this front will mainly be focused on the northeast gulf and north central panhandle. Southwesterly flow starting a warming trend so expect more rain than snow with only minor accumulations of a couple of inches for the far north and at higher elevations. Surface ridge builds over the gulf behind the front for a drying trend starting late Wednesday night into Thursday. This will be short lived. The next major low will have moved south of the Aleutians by this time with associated gale force front crossing into the central gulf. The front will reach the eastern gulf then panhandle early Thursday evening into Friday morning. Winds will reach at least gale force over the gulf and potentially higher. Small craft winds will increase over the inner channels. With the warm southerly flow once again expect more rain than anything from this front, but that rain may be heavy. The surface low will eventually track eastward through the weekend followed by weak ridging. New model runs were mostly in line with previous forecast regarding position of the incoming system, a slight increase in speed for the Thursday evening low/front. Mostly refreshed/increased winds to a blend of GFS/ECMWF and increased pops for the Thursday front. Due to southwesterly flow did not drop pops off completely between systems but greatest chance for dry/clear skies is over the southern panhandle. More indications of warmer overnight temps due to higher 850 mb temps/SW flow and precip/cloud cover so also nudged up lows a few degrees. Forecast confidence is average. && .AJK Watches/Warnings/Advisories... PUBLIC...None. MARINE...Small Craft Advisory for PKZ022-034-036-043-051>053. Small Craft Advisory due to Seas for PKZ041-042. && $$ RWT/PRB Visit us at http://www.weather.gov/Juneau

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