textproduct: Juneau

SYNOPSIS

Key Messages:

- A low marine layer will impact the outer coast and filter into Icy Strait and the Southern Inner Channels through Wednesday morning.

- Scattered showers return Wednesday afternoon into Thursday morning for the southern and central panhandle, with skies clearing through Thursday afternoon and Friday.

- Another front moves into the northern gulf coast Saturday, with rain likely for the northern panhandle. The rest of the panhandle seeing above normal temperatures for the weekend.

LONG TERM

Simply put, Friday, anticipate a nice day with sea breezes for the region. Friday night we start to see a tale of two regimes: wet for areas north and west of Frederick Sound and potential for warm and dry south of Frederick Sound.

Touching on rain first, a gale force system will lift into the western Gulf late Friday, bringing southeasterly sustained winds of near-gale force to strong breezes to most of the coast into Saturday. Seas will also increase, likely reaching near 14 ft along the northern coast. Rain will also accompany this system, with the focus on heaviest rain near Prince William Sound; however, expect light to moderate rain for areas north and west of Frederick Sound, especially west of Cape Fairweather. For all communities, we anticipate 24 hour rain total to remain below 3 inches.

Now an interesting turn of events is taking place in the southern Panhandle by Sunday. As guidance continues to shift the rain a bit west, this means we will see drier conditions for Prince of Wales and Ketchikan. One consequence of this will be potential loss of cloud over and see temperatures in the upper 70s to possible low 80s before rain and cooler temperatures arrive Monday. As of Tuesday afternoon, our published forecast is trending warmer and drier for this weekend in the south. Stay tuned.

AVIATION

/18z Wednesday to 18 Thursday/ A marine layer of low clouds lies across the outer coast and has spread inland across the southern inner channels. Ceilings are lowest over Yakutat (400- 600ft) and down to MVFR over PAGS and the southern panhandle. Through this morning, the MVFR clouds have advanced northward into Frederick Sound due to southerly surface winds and a large sunny break to the north of it and over northern BC. The expectation is that the marine layer clouds will lift some through the afternoon then lower again this evening with some potenial for drizzle. Outside of the marine layer, sea breezes are becoming established and the larger scale W-SW surface flow is adding to that. Expect those sea breezes to peak through the afternoon as usual, then decrease overnight, becoming light and variable into early Thursday.

MARINE

Inner Channels: Winds in Lynn Canal are still holding out south of Taiya Inlet with gusts up to 28 kt as of 4am. Icy Strait also looks to see increased winds through the morning hours of 15 to 20 kts. These winds are expected to slacken through late morning. Through the day Wednesday, winds across the panhandle look to be overall lower than Tuesday due to less diurnal heating as a result of more cloud cover. Stronger sea breezes are expected to return on Thursday with sky cover diminishing (warm land areas near colder water driving the sea breeze circulations).

Outer Waters: Marine stratus over a majority of the Gulf of Alaska will be the primary potential headache for mariners Wednesday morning. Within this marine layer, expect patchy fog with visibilities less than 1/4SM possible. This layer is expected to remain in the general vicinity of the Gulf through the majority of the week.

Looking at the winds over the outer waters - predominantly NW winds will continue to be funneled along the near shore terrain, creating pockets of increased wind around the predominant capes. Sustained winds are expected to be around 20-25 kts, especially around Cape Spencer. Winds on Wednesday across the Gulf are expected to be lighter, and this terrain based forcing is not as likely to occur. However, increased winds are expected on Thursday, especially north of Cape Spencer, due to increasing pressure gradient as a low pressure system moves in from the west. This low pressure system is expected to move into the gulf Friday night with near gale force winds north of Cape Spencer.

AJK WATCHES/WARNINGS/ADVISORIES

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