textproduct: Juneau

UPDATE.../For 06z TAF issuance/

Winter maintains its grip across SE AK, though more so in some locations than in others. Snow continues across the central panhandle, with rain for the south. The northern panhandle will remain dry and cold through Monday, and while blustery conditions and an upper level cloud deck are expected at times, VFR conditions will remain prevalent for Skagway, Haines, and Yakutat.

The Icy Strait Corridor southward will prove a different story. The current band of snow is shifting northward, and will be reinforced by a wave racing up from the south through the overnight hours. Slowly warming temperatures in the southern panhandle on Monday will lead to the rain/snow line reaching as far north as Wrangell by Monday evening. However, with the band of snow lifting north, chances of snow, and subsequent VIS reductions to low end MVFR or into IFR, increase across the Icy Strait Corridor by late Sunday night. CIGS and vis across the central panhandle will remain IFR/MVFR between 0.5k and 2k feet through Monday. Weak LLWS develops overnight as winds 2kft aloft becoming 20-30kt. A pocket of LLWS and mountain wave activity is possible for the southern approach near PAJN as east- northeast 30+kt cross barrier flow develops.

SYNOPSIS

- Moderate to heavy snowfall continues across the SE AK panhandle Sunday into Monday. Multiple warnings and advisories remain in effect across a majority of the panhandle for additional snow accumulations up to 9 inches through Monday morning. - Additional winter weather products have been issued for a follow up snow event Monday night into Tuesday. Heavier snow is expected to impact the central panhandle, with potentially lighter snow north of Angoon depending upon the track of the system.

- More active weather pattern lasts through the rest of the week and into the weekend as systems continue to move into the Gulf.

LONG TERM.../Wednesday through this weekend/

Onshore southwesterly to westerly flow and upper level shortwaves will work to keep systems moving into the panhandle, with the current active weather pattern lasting through the rest of the week and into the weekend. The next system to move in after the Tuesday system will be Wednesday night into Thursday morning as a low moves NE into the Gulf before looking to move up into the N coastline, through models are not showing much confidence on the exact position or trajectory of the low as it moves in with plenty of spread across the ensembles. Despite the spread on the low positions for both this system and the next moving in Friday into Saturday, there is some agreement on the low center staying further westward, between south of Yakutat to the NW Gulf near Kayak Island. It seems that some of the lack of model agreement in the long term is related to the strength of the upper level ridge over the Gulf and SE AK. This is especially impacting the current model agreement on the next impactful system Friday into Saturday, with nearly half of the ensemble clusters pushing for a more SW-ly flow aloft with the low pushing in more directly into the NE Gulf and closer to the panhandle, and half suggesting a solution of the low remaining further west towards Anchorage with the stronger upper level ridging over the Gulf and the trough staying a bit further westward. The models appear to show more confidence for the cooling trend this weekend as the low center begins to bring some colder air down and across the Gulf into the panhandle, regardless of the positioning of the low center being a bit further west, with a more zonal to almost NW-ly flow setting up aloft.

The lack of model agreement and overall spread between the two main solutions are making some of the precipitation amounts uncertain at this time, particularly for Yakutat as the position of the low Thursday will make a difference in how much snowfall they receive. Overall QPF amounts are not looking too impactful for Wednesday through Friday, but the Friday into Saturday system may bring a bit more precipitation. The continued warming trend Thursday through the early weekend will begin to transition more of the central panhandle to rain, and transition the northern panhandle to more of a wintry mix with the warmer onshore flow. Not as much snow accumulation for this reason, even as QPF amounts look to be higher for the Friday / Saturday system, due to the warmer temperatures and wet bulb temperatures and higher snow levels pushing in across the N panhandle.

AVIATION.../through Monday night/

VFR conditions north of the Icy Strait Corridor last through Monday, with strong winds blowing out of Skagway. However, the Icy Strait Corridor southward will prove a different story. The current band of snow, although it has begun to slowly weaken, is shifting northward, and will be reinforced by a wave racing up from the south through the overnight hours. Slowly warming temperatures in the southern panhandle on Monday will lead to the rain/snow line reaching as far north as Wrangell by Monday evening. However, with the band of snow lifting north, chances of snow, and subsequent VIS reductions to low end MVFR or into IFR, increase across the Icy Strait Corridor by late Sunday night. CIGS and vis across the central panhandle will remain IFR/MVFR between 0.5k and 2k feet through Monday. Weak LLWS develops overnight as winds 2kft aloft becoming 20-30kt. A pocket of LLWS and mountain wave activity is possible for the southern approach near PAJN as east- northeast 30+kt cross barrier flow develops.

Winds from Icy Strait corridor south will generally be less than 10kts, except 10-15kt at times across the southern panhandle this afternoon and evening as the low pressure moves across. Increasing northerly outflow for PAHN and PAGY will bring winds 15-25G25-35kt.

Further north for PAYA quiet weather will prevail, with VFR flight conditions and light winds.

MARINE

Inside (Inner Channels): Northerly outflow conditions have increased throughout the day with near gale to gale force winds of 28 to 40 kts through Lynn Canal and into Point Couverden. These stronger winds will continue through tonight before slightly diminishing tomorrow morning. Along with these winds, fully developed seas, up to 8 ft, and times of heavy freezing spray are likely tonight. This will create hazardous marine conditions through Lynn Canal into the Icy Strait, northern Stephens Passage, and northern Chatham Strait areas. Even though winds will slightly diminish on Monday, a low moves northeast into the gulf on Tuesday once again increasing northerly outflow winds. This will create widespread gale to strong gale force winds, with storm force wind gusts possible, across Lynn Canal and into Point Couverden. Once again, fully developed seas will build along with freezing spray. At this time, southern channels, especially Clarence Strait into Sumner Strait, will start to see winds become southerly. We will then continue to see winds become southerly across the inner channels through the end of the week.

Outside (Gulf and Coastal Waters): Outflow winds have begun to dominate the gulf with easterly fresh to strong breezes coming out of common gap wind areas like Dangerous River and out of Cross Sound. As winds continue, seas will build to 8 to 10 ft out of the aforementioned areas. Otherwise, seas remain around 5 to 7 ft across the gulf. These winds will continue for the NE gulf coast into the start of the week as another low pressure system moves NE into the gulf late Monday into Tuesday. This low will strengthen the pressure gradient, in turn strengthening those common gap wind areas to gale force winds. It will also allow winds south of the low to become westerly and increase to strong breezes to near gales. Outflow winds will begin to diminish Tuesday night as the low pushes inland. At that time increased winds will continue along the southern gulf. Winds will then greatly relax through Wednesday, giving the gulf a slight break before another system arrives late week.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Cold Weather Advisory until 9 AM AKST Monday for AKZ318. Winter Storm Watch from late Monday night through late Tuesday night for AKZ320>325-327. Winter Weather Advisory until 9 AM AKST Monday for AKZ323-327. Winter Storm Warning until 9 AM AKST Monday for AKZ326. Winter Weather Advisory until 6 AM AKST Monday for AKZ328-329. MARINE...Heavy Freezing Spray Warning for PKZ011>013-053. Gale Warning for PKZ012-013. Small Craft Advisory for PKZ011-022-031-641>644-651-661>664-671.