textproduct: Juneau

SYNOPSIS

Key Messages:

- Gale force system continues to push away towards southern British Columbia, leading to generally diminishing wind and seas across the region.

- Wednesday is expected to be a break day with more seasonable temperatures: highs in the 40s across much of southeast Alaska, with low 50s possible for the southern panhandle.

LONG TERM

The end of the week into the weekend will bring more typical southeast springtime weather with a sub- gale force low and front to quickly advance into the Gulf of Alaska through Thursday. In response to this low, anticipate cloud cover to increase ahead of the front Thursday morning, with widespread precipitation expected late Thursday into Friday. Now the main question is precipitation type: rain or snow? The source of this low is the more typical Aleutian storm track, with warmer air aloft than what we have previously seen the last few weeks with our storm cycles. While this warm air certainly suggests that rain will be the dominant precip type, the biggest question is how weak outflow winds will continue keep protected interior sections of southeast cooler at the surface. However, we have spring sunshine and longer days to help with warming. Considering this, the current forecast has a quick hit of wet/heavy snow for the region Thursday night and a transition to rain Friday, with the northern Panhandle transitioning later Friday morning. Snow levels will likely increase to above 1000 ft for much of the Panhandle by Friday afternoon as surface temperatures warm into the 40s.

One item of note is that while Thursdays low looks to remain below gale force for much of the eastern Gulf, mariners operating along the coast should be vigilant for another round of elevated seas Friday into the weekend.

For the long term update, the pattern this weekend into Monday remains on track, with a continuous lower-level warming trend favoring mostly, if not all, rain across the panhandle from early Friday morning through Sunday. Rainfall will be minimal, with high confidence of less than an inch, due to weak upper-level forcing and seasonally average precipitable water with the frontal passage. Winds are also trending downward, with minimal impacts mostly confined to the southern panhandle coastal waters. Another weak low moves onshore Monday in the southern region, bringing more light precipitation throughout the day.

AVIATION.../through 12z Thursday/

VFR conditions continue across the panhandle, with a majority of sites seeing clear skies and calm winds. Haines and Wrangell are the exceptions for wind, with Wrangell seeing up to 10 kts of southeasterly winds and Haines seeing northwesterly outflow gusts up to 25 kts through the early morning. The other exceptions are Juneau and Gustavus, both seeing a very patchy, shallow fog layer persist through the morning. Conditions are largely staying VFR, with the occasional drop in VIS from this fog layer becoming slightly more thick. With how this fog has trended overnight, conditions are expected to remain VFR with the fog layer staying too shallow to bring VIS down for an extended period of time and below freezing temperatures potentially forcing the layer to frost out through the morning.

Other than the potential for localized fog development through the morning, conditions are expected to stay largely clear through the period. Outflow winds are expected to pick up through midday Wednesday, increasing to 10 to 15 kts through the afternoon for most sites. Gusts up to 25 to 30 kts will continue through Haines and pick up for Skagway, and LLWS at 1000 ft is expected down Gastineau Channel in Juneau due to northeasterly outflow winds from Taku Inlet. Through the end of the period, wind speeds are expected to diminish again. Upper level clouds should begin to move in from southwest to northeast going into Thursday morning as a front moves towards the panhandle by Thursday night.

MARINE

Outside Waters: The gale force low continues to shift away from the region towards southern British Columbia, with winds and seas continuing their downward trend through Wednesday night. Seas 9 to 13 ft this morning will drop down to 4 to 7 ft tonight. Winds becoming more northerly 10 to 20 kt today, then dipping down to 5 to 15 kt overnight. Another low and front swing through the Gulf for Thursday and Friday, with winds becoming strong to possibly gales and seas increasing to 10 to 15 ft

Inside Waters: Moderate outflow conditions continue across the inner channels this morning, with strong northerlies in Lynn Canal. Winds will diminish through tonight as the gradient weakens with the low pushing further away. Winds pick up from the south becoming fresh to strong across the central/southern inner channels by later Thursday and continuing into Friday with the approach of the next low and front, with gales possible for Clarence Strait. Weaker outflow conditions will likely continue across the northern channels.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...Small Craft Advisory for PKZ012-013-641>644-651-652-661>664- 671- 672.