textproduct: Juneau

LONG TERM

Convective snow showers continue into Thursday with cold air advection streaming across southeast AK, with a vertically stacked low and unseasonably cold temps aloft. However, northerly outflow will filter in drier continental air into the northern panhandle by Thursday afternoon behind the low passing southeast over the panhandle, effectively shutting off the snow from the Icy Strait corridor north. Showers will diminish significantly across the rest of the panhandle as well. An additional 1-3 inches of snow possible from Icy Strait south, with heavier amounts expected across near Port Alexander and Prince of Wales Island. Snow will develop back into the region on Friday with onshore flow, but lack of any significant forcing will keep fairly scattered and light.

With the northerly outflow strengthening and much below normal 850 temps aloft, expecting cold temps across southeast AK for the end of the week. Expect highs in the teens and lower 20s north to upper 20s and 30s central and south. Nighttime temps will dip down into the single digits to lower teens north to upper teens and 20s south. Below zero temps are possible along the northern highways, esp Thursday night, and there is the potential they reach Cold Weather Advisory criteria.

For the weekend, general model trend is for a frontal boundary straddling over the central/southern panhandle with ridging to the south and upper low to the north and a steady upper-level jet overhead. Multiple waves and upticks in moisture will pass along the boundary and through the panhandle, bringing more snow. Preliminary forecast is showing light to moderate snow along the Icy Strait corridor and Juneau with 4-6 inches possible, with heavier amounts up to 8+ inches possible south along the coast and over central/southern panhandle. Warmer air and rising snow levels could bring a rain/snow mix or all rain that would eat into snow total across the south. The drier air north of the boundary will limit the potential for significant accumulations for Yakutat and especially Skagway and Haines. Temperatures moderate a bit over the weekend as the arctic air retreats and the northerly outflow weakens.

AVIATION

as rain and snow persist. Conditions are expected to continue with onshore flow and a low over the Gulf bringing precipitation to the area. Ceilings and visibilities are expected to increase during the lighter periods of precipitation but will decrease during the heavier periods. The precipitation impacting the area is expected to become more showery headed into tomorrow. With the showery nature, some areas could see improvements potentially up to VFR conditions while areas in the showers could be dropping down to LIFR due to the potential for heavier showers. One concern headed into tomorrow with the showers is the potential for some showers to potentially develop into convection with the potential for a lightning strike or two. But this is something that will need to be watched going into the day.

MARINE

Inner Channels: Winds are predominately southerly today with the highest winds across the central inner channels. Five Fingers, Scull Island, and Rocky Inland are all blowing 25 to 30 kt out of the southeast most of the afternoon. Otherwise most areas are around 15 kt or less for winds right now. Inner channels winds are expected to diminish tonight but when the higher westerly winds in the gulf reach the panhandle on Wednesday, the more east/west channels (like Icy Strait, and Frederick Sound) will see some increases in W to SW winds to around 20 to 25 kt. Finally toward late Wed night, northerly outflow will be starting up in the north so expect winds to switch from S to N for Lynn Canal and Glacier Bay with Lynn Canal winds increasing to at least min gale force by late Wed night. Seas will mainly be around 4 ft or less with some areas seeing up to 6 ft with the higher winds as they crop up. Some freezing spray will likely returns for the far northern channels late Wednesday night as outflow starts up and air temperatures start dropping.

Gulf Waters: Expect increasing W winds through Wednesday that will then last into wednesday night before diminishing. The central and southern gulf will see winds reaching mid range gale by Wednesday that will likely last into Wednesday night. Seas are sitting around 7 to 10 ft currently with the highest seas in the southern part of the gulf (Swell is around 7 to 8 ft from the SW at a period of 8 sec). Expect seas to increase with a long fetch of increasing winds across the entire West to east distance of the gulf. Seas max out around 20 to 30 ft by Wednesday evening before starting to subside into Thursday. One other thing is the possibility of freezing spray for even the central gulf waters by Wed night due to the cold air streaming across the gulf and the higher winds. It is mainly going to be light in intensity though.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Winter Weather Advisory from 6 AM to 9 PM AKST Wednesday for AKZ318. Winter Weather Advisory from 9 AM Wednesday to 6 AM AKST Thursday for AKZ322. Winter Weather Advisory from 6 PM Wednesday to 4 PM AKST Thursday for AKZ323-328. Winter Weather Advisory until 6 AM AKST Thursday for AKZ325. Winter Weather Advisory until 6 PM AKST this evening for AKZ326. MARINE...Gale Warning for PKZ661-663-664. Small Craft Advisory for PKZ011-021-022-031-034-035-053-641>644- 651-652-662-671-672.