textproduct: Juneau

UPDATE.../to add the 18z aviation discussion/

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, most likely in the morning hours.

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

LONG TERM

Mid range pattern remains consistent; an amplified ridge will remain in place over southeast, with the axis stretching into southcentral AK. This feature will continue to block large systems from making landfall over southeast, with a cool arctic airmass dominating the Yukon and B.C. territories driving outflow for the inner channels. Magnitude of outflow winds looks to remain below gale force for the most part with the exception of gale force gusts for localized areas like Taku Inlet and perhaps Taiya. By the weekend, a prominent system in the far southwest gulf will push some moisture into southeast bringing light precipitation and increasing wave energy along the coast.

Though there is still lots of spread between models, overall guidance suggests a small upper level disturbance moving into the eastern gulf 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.../Until 18Z Wednesday/

A northerly outflow wind pattern is in place, which is bringing breezy/gusty conditions through the 24-hour TAF period for the northeastern Panhandle/Lynn Canal region sites, including PAGY & PAHN. Winds elsewhere across Southeast Alaska are on the lighter side as the the SFC pressure gradient is much more relaxed. As far as CIGs and VISs are concerned, VFR flight conditions are expected for most areas through the period. The exception looks to be the PAPG area, which will see LIFR category conditions from dense FG through this morning, improving to VFR. Then, tonight, conditions for PAPG look to deteriorate again for several hours. LLWS values continue to be rather benign through the period.

MARINE

Inside (Inner Channels): Lighter outflow winds continue across most of the inner channels today, with the exception being Lynn Canal and Taku Inlet, which could see moderate to strong breezes through tonight as the gradient tightens. Pockets of dense fog continue across portions of central/southern inner channels this morning, but looks dissipate by this afternoon. The outflow continues to build across the inner channels through the week with speeds of strong breezes to near- gale force. One benefit of outflow will help limit fog potential as we move through the week. Mariners should continue to watch for fog development in protected bays and inlets.

Outside (Gulf and Coastal Waters): High pressure continues to bring fairly benign marine conditions across the outside waters. Winds and seas looks to increase by late week and into the weekend as a series of low pressure systems push north into the Gulf waters. Outflow winds also look build through the week, with fresh to strong breezes coming out of Cross Sound by Friday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Freezing Fog Advisory until noon AKST today for AKZ321-326-327. Dense Fog Advisory until noon AKST today for AKZ328-330. MARINE...Small Craft Advisory for PKZ012.