textproduct: Juneau

SYNOPSIS

Key Messages:

- Rain showers diminish through Monday night across the panhandle.

- Partly to mostly sunny skies and warmer temperatures are expected for Tuesday. Temperatures look to reach mid to upper 60s across the panhandle. Sea breezes will pick up through midday.

- Chances of rain return Wednesday concentrated mainly to the southern and central panhandle.

LONG TERM.../Thursday through Saturday/

An area of lower pressure in the upper levels looks to move across the panhandle on Thursday, putting a damper on most of the active atmospheric forcing across the panhandle. Winds aloft look to be extremely light with off shore flow directions, which is likely to dry out the panhandle through the day. This trend of diminishing precipitation is then followed by clearing skies through the day Friday as a strong upper level ridge takes its place over the panhandle. This ridge building in, and an upper level low, then aims a strong jet at the northern gulf coast. Models are indicating a plume of moisture associated with this this jet, which looks to bring rain back to the northern panhandle on Saturday. The exact position and magnitude of this upper level jet and the moisture associated with the surface low still have strong spread between models, but the current thinking is Yakutat will get receive moderate rainfall, with precipitation chances falling as you move south down the panhandle on Saturday.

Winds through the period look to be relatively calm due to an east/west gradient that takes hold of the panhandle. There is potential for sea breezes on Friday due to clearer skies allowing more daytime heating. The threat moves in as the low pressure system in the western gulf builds in, bringing stronger winds to the northern outer coast of the panhandle. Winds look to build Friday night and continue through the day Saturday. Confidence is high that winds in the gulf could reach 20kts sustained with gusty candidness. Local forcing, like the coastal jet, could cause winds to build even higher.

AVIATION.../Through 00z Wednesday/

Widespread VFR conditions continue through a majority of locations, with a mid-level cloud deck around 4000 to 6000 ft traversing northwestward across the panhandle. This band has shifted slightly southwestward through the morning, allowing for areas north of the Icy Strait Corridor to start clearing from north to south. Potential for the occasional light shower still exists for the southern and central panhandle, though a few brief pockets of wetting rain have been observed as far north as Juneau and Gustavus. Some of the showers are bringing CIGs down to MVFR in the far southern panhandle, but these will lift back up as the shower passes. Winds are still relatively light for most locations, only picking up with any heavier shower that blows through. Any locations seeing broken ceilings most likely have felt onshore sea breezes start to pick up, with southerly winds around 10 to 15 kts in Northern Lynn Canal and going into Skagway.

Through the rest of the afternoon, the band of clouds will continue to slowly shift out of the northern panhandle. The southern panhandle will continue to see potential for showers overnight as the associated system in the gulf continues to direct mid-level clouds overhead. The most likely places to see these showers are the far southern tip of the panhandle. Throughout the period, skies will clear more and more from north to south. This will allow for onshore sea breezes to once again take over through the morning, increasing by the afternoon.

MARINE

Gulf(Gulf and Coastal Waters): As of Monday afternoon, ASCAT/AMSR2 wind passes highlight winds below 25 knots, with coastal buoys reporting ESE moderate breezes along the Fairweather Grounds. Sea state is a combination of southerly swell of 16 seconds at 2 ft and southeasterly fresh seas 7 to 8 seconds at 6 to 8 ft. Fresh seas will slowly subside this evening, allowing the southerly swell to continue to flourish. Tuesday a ridge begins to build across the eastern Gulf, with northwest winds building to near 15 to 20 knots into the midweek. Highest winds along Cape Decision and western Prince of Wales coast. South ground swell near 16 to 19 seconds at 3 ft will move in Thursday. Deep water significant wave heights remain below 6 ft through the week.

Areas of gale force to near-gale force winds and seas near 14 ft are likely along our coast this weekend.

Inside (Inner Channels): Monday afternoon surface observations across the inside are showing winds less than 20 knots, except for Taiya Inlet. One excellent report was from the vessel David B via the Marine Exchange of Alaska, giving us some insight into the upper arms of Glacier Bay. Moving through the next few days, diurnal sea breezes become the primary threat. Mariners navigating northern Lynn Canal should be aware of afternoon winds reaching moderate to fresh breezes (11 to 21 knots). For folks heading into Glacier Bays Bartlett Cove, be aware of southwesterly winds near 15 knots coming out of Icy Strait Tuesday afternoon.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...None.