textproduct: Juneau

SYNOPSIS

Key Messages:

- Strong north and northeast winds continue slightly diminishing throughout the day Tuesday. Winds will relax late Tuesday into Wednesday.

- Temperatures continue to trend down through the week.

LONG TERM

Wednesday night the axis of a ridge aloft will continue transiting east into B.C, with the stout pressure gradient which was responsible for our strong outflow weakening, leaving much lighter winds for the inner channels. Westerly flow upstream of the ridge axis will begin to transport some moisture into the Panhandle early Thursday, helping drive some snow Thursday into Friday. Current forecast shows the best snow potential along the northern coast and in the central and southern Panhandle, with a range of 3 to 7 inches possible; 2 inches or less for Juneau north. Friday the longwave trough begins to dig south, forming into a closed low along the western seaboard over the weekend. As this feature transits south, a very tight surface pressure gradient forms again between an arctic high in Canada and the relative warm waters of the Gulf, increasing the confidence that strong gale force outflow winds return for many inner channels through the weekend with the associated colder weather and freezing spray.

Into early next week, outflow diminishes again as the Yukon high weakens and a new weather system moves in from the W. The possibility of precipitation returns for most areas by Tuesday with most of the areas likely still cold enough for it to be mostly snow.

AVIATION

Clear skies continue for most of the panhandle this morning with the exception of some clouds for the outer coast and areas north and west of Yakutat. VFR conditions are expected to continue this morning as outflow continues but will be weakening during the day today. With the weakening winds, the potential for LLWS and turbulence around ridge top level should diminish as well. Conditions are expected to slowly start deteriorating towards the latter half of the TAF period as a low is expected to move across the northern Gulf tonight bringing more clouds and an increasing chance for precip. CIGs could drop down to MVFR with clouds moving in for portions of the NE Gulf and central panhandle locations.

MARINE

Outside: Offshore flow from the channels diminishes through Wednesday morning, and seas are on their way down, with residual NW seas, masking SW swell generated from a system a few days ago south of the Aleutians. Significant heights less than 12ft by Tuesday evening, and between 5-9 feet on Wednesday, with the highest seas over the open Gulf. Mariners should be aware of lingering northerly outflow out of major inlets/bays along the northern coast, reaching close to gale force through Wednesday morning.

Inside: Winds continue to diminish Wednesday, with moderate to fresh breezes expected for most locations by late Wednesday afternoon, then lasting through Friday morning. Lynn Canal may hold onto winds closer to 15-20 kt for slightly longer, but they should likewise follow suit by late Wednesday or evening. However, Friday evening winds are expected to ramp back up to gale force for most central/northern channels with the threat of heavy freezing spray becoming more extensive.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Cold Weather Advisory until 9 AM AKST this morning for AKZ318- 319-323-325>329-331-332. Cold Weather Advisory from noon today to 6 PM AKST this evening for AKZ328. Cold Weather Advisory from noon today to 3 PM AKST this afternoon for AKZ329. Cold Weather Advisory until noon AKST today for AKZ330. MARINE...Heavy Freezing Spray Warning for PKZ011-012-031. Gale Warning for PKZ012. Small Craft Advisory for PKZ013-031-661-662.