textproduct: Juneau

SYNOPSIS

Key Messages:

- Decent break in weather for much of the region through most of the week.

- Main threat to mariners and aviators is periods of dense fog, with freezing fog likely this morning.

- Active weather returns by late weekend, with rain for most of the panhandle. Accumulating snow possible for the north.

LONG TERM

Through the end of the week a persistent ridge will continue to dominate southeasts weather, blocking major storms from making landfall over our neck of the woods. Main threat remains in outflow winds, with ensemble systems showing a slight increase in surface pressure gradient between the Gulf and our Canadian neighbors. Given the NE to SW pressure gradient, thinking Taiya and Taku Inlet see near-gale force winds Thursday/Friday with strong breezes to near-gales for Lynn Canal. These outflow winds will help cool arctic air infiltrate southeast, increasing chances for a few inches of snow as a wave of moisture moves over this weekend; mainly for communities in close proximity to the Coast Mountains.

Though there is still lots of spread between models, overall guidance suggests a small upper level disturbance moving into the gulf late Saturday night. The resulting surface inflection looks to send a front into the panhandle through Sunday, bringing widespread precipitation back to the panhandle into Monday. This system has the possibility of bringing gale force winds along the outer coast, with strong gusts pushing up into the channels. The pressure gradient in the northern panhandle will attempt to keep strong northerly outflow winds through Lynn Canal as the low moves inland. Temperatures will be the more uncertain part of the extended forecast, as outflow during the week bringing cooler temperatures southward will be combating the southerly onshore flow associated with the low. CPC guidance suggests overall warming temperatures next week with the more active weather, but due to the weakening outflow winds persisting in Lynn Canal, northern panhandle communities still have a chance to see this precipitation fall as snow before most likely changing over to rain by early next week. Precipitation still looks to remain on the lighter side of what is typical for Southeast Alaska, though continued onshore flow and another potential broad low following behind should keep relatively consistent precipitation in the forecast for next week.

AVIATION

Similar to the past few days, predominantly VFR conditions across most of the panhandle, with periods of IFR and LIFR, especially across the central panhandle and the Icy Strait Corridor as fog redevelops. Warming temperatures will result in (less) freezing fog, and more 'standard' fog formation. As is so often the case with fog, that likely means that CIGS and VIS will fluctuate through Wednesday. The far northern panhandle (Skagway and Haines) will instead see outflow winds, especially Skagway, resulting in stronger low level winds.

MARINE

Inside (Inner Channels): Lighter outflow winds continue across most of the inner channels today, with the exception being Lynn Canal and Taku Inlet, where winds are moderate to fresh with strong winds in Taiya Inlet. Pockets of dense fog continue across portions of central/southern inner channels this morning, with thicket across Frederick Sound, Clarence Strait and portions of Glacier Bay into western Icy Strait waters. Fog looks to dissipate this afternoon, but patchy development is possible again tonight. The outflow continues to build across the inner channels through the week with speeds of strong breezes to near-gale force. Lastly, there is a chance to see light freezing spray develop across Lynn Canal later this week due to increasing winds and decreasing temperatures. We will continue to monitor this possibility.

Outside (Gulf and Coastal Waters): High pressure continues to bring fairly benign marine conditions across the outside waters. Pockets of dense fog linger from Cape Edgecombe down to Dixon Entrance. As outflow winds build through the week, expect fresh to strong breezes to come out of Cross Sound, and other common outflow locations, by Friday. Then this weekend, a change in pattern comes due to a series of low pressure systems pushing north into the Gulf waters. This will allow gulf winds and seas to increase and remain elevated.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Freezing Fog Advisory until noon AKST today for AKZ321>322-326>328. MARINE...