textproduct: Juneau

SYNOPSIS

Key Messages:

- Low and frontal band moving into British Columbia Coastline just north of Vancouver Island Friday.

- The next big low (roughly in the mid 960mb range) to impact Southeast Alaska Sunday as it and the associated frontal band moves through the SE Gulf of Alaska on Sunday.

LONG TERM.../Sunday through Friday/

A fairly active pattern will continue for Southeast Alaska through the long term period. A significant low pressure system moving northward toward the area late Saturday and into Sunday. This system currently appears to be the most worthy particularly for the southern panhandle, with increasing forecast confidence in strong winds (40-50mph) for areas south of Port Alexander. The uncertainty on the exact strength of this system is due to how quickly and where the low that moves through on Friday dies out. If the Friday low weakens and dies out over by PWS before the late Saturday-Sunday system moves in then the southern panhandle could see sustained SE winds closer to the 45-55mph. In addition to wind this low will bring a round of rain and high elevations snow (including the Haines and Klondike Highways). This low will continue to move north and then west toward Prince William Sound late Sunday and into Monday and weaken. Multiple shortwaves after this system will move through the area each brining their own bouts of preciptiation. What is more noteworthy during this period is the gradual lowering of snow levels through the rest of the week. Current guidance even has snow levels dropping down to around 1000 feet with for areas along the Coastal Range and the northern Panhandle late next week. As a result if precipitation were to be also moving through due to a shortwave disturbance there would be the potential for it to fall as snow or rain/snow mix at sea level. All that said there is still great uncertainty when it comes to that time frame and multiple things would have to align, but it is certainly something to watch.

AVIATION.../Through 12z Saturday/

Primarily VFR flight conditions with hit or miss LIFR visbys and cigs conditions due to fog this morning across the northern panhandle. Across the southern panhandle, an overcast cloud deck around 5kft is slowly moving its way northward as a low in the N Pacific transit NW towards Prince William Sound through Friday. Any lingering fog across the northern panhandle through Friday morning as this low moves northwestward with periods of rain once again expected across the panhandle. As rain passes, there may be short periods of MVFR ceilings around 2000 to 3000 ft, but forecast confidence remains high that ceilings and visibilities will remain predominate VFR into Friday evening. Northerly winds strengthen near Haines and Skagway with wind gusts around 30 kts through Friday morning. Otherwise, winds remain largely 10 kts or less across the other terminals, with isolated gust up to 20 kts this afternoon. No significant LLWS concerns through the TAF period, but will need to watch for increasing SE- ly winds aloft across the S panhandle by Saturday morning.

MARINE

Outer waters:

Predominantly northeasterlies out of interior passes from Cape Spencer southward through the morning hours up to 30 knots shifting southeasterly as a weak low moves into the central gulf. Big highlight for the morning hours will be the strong southerly swell to 15 ft as a result of the strong low south of Haida Gwaii. This combined with the stronger northeasterly, opposing the swell, has wave heights ranging between 15-18 ft south of Cape Edgecombe.

Expect seas to mitigate somewhat to around 9-12 ft as the weak low moves into the central gulf, before increasing from a stronger system moving northward. Long fetch windows with at least gale force winds will generate higher significant wave heights for the same areas previously mentioned, around 20-25 ft. Still a fair amount of uncertainty for how this system will move up, particularly regarding timing of gale to strong gale force winds along with wind direction, ranging between more southerly to more easterly.

Note: Buoy 46082 (Cape Suckling) was ripped from its mooring and set adrift during the powerful storm Monday Nov 9. Data is no longer available for this sensor.

Inside Waters:

Stronger northerly winds are in full effect, with north south facing channels experiencing up to 30 knot winds for the northern half of the panhandle. Expecting these to diminish fairly quickly as the weak low moves into the central gulf, effectively shifting the highest winds from the north south facing channels to more easterly in nature. For the southern half of the panhandle inner waters, expect a gradual increase in wind speeds Saturday into Sunday as the stronger low pressure moves near the panhandle. Gale force winds for Clarence Strait look to begin Saturday night, through have the possibility to begin as late as Sunday morning, depending on how this stronger low will move up the coastline.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Wind Advisory from 6 PM Saturday to 6 AM AKST Sunday for AKZ328. MARINE...Gale Warning for PKZ641-661. Small Craft Advisory for PKZ012-013-022-031-033-036-053-642>644- 651-652-662>664-671-672.