textproduct: Juneau

SYNOPSIS

Key Messages:

- Clear skies and warm daytime temperatures taking with high temperatures into the upper 60s and isolated locations into the low 70s.

- Another front moves into the Northern Panhandle through Tuesday, with increasing marine winds across the inner channels and elevated seas along the coast.

LONG TERM

/Wednesday Through Saturday/ The mid to long term forecast remains mainly unchanged as a low along the Aleutian chain moves into the Gulf of Alaska late Tuesday into Wednesday. This low will send a front into the panhandle bringing widespread rain showers into SE AK. The NE gulf coast is most likely to see periods of moderate showers with slightly elevated winds. On the other hand, the southern panhandle is more likely to see longer breaks between showers. The main impact from this low, Wednesday into Thursday, will be increased southwesterly swell along the gulf and into the gulf coast. The significant wave heights along the gulf are anticipated to be around 15 ft at a period of 15 to 20 seconds.

Winds greatly decrease Thursday and remain on the lighter side into the weekend as the low continues to weaken. However, this low will continue to allow shower development into the panhandle with continued onshore flow. Overall QPF remains on the lower side as these showers are anticipated to be on the lighter side. Similar conditions will continue into the weekend with breaks in between showers. Along with this, slightly warmer maximum temperatures, than what we have seen, are anticipated late this week through the weekend. There is even a slight chance, around 40%, that portions of the southern panhandle could see temperatures into the low 70s during the start of next week. We will continue to monitor this potential as it is still a week away.

AVIATION

/through 00z Wednesday/ VFR conditions ongoing across the panhandle with a SCT deck around 5000 to 7000ft as ridging and on-shore flow moves in from the west across the Gulf as remnants of a low tracking SE into the N Pacific towards Vancouver. Anticipating VFR conditions to prevail for majority of the TAF period for all TAF sites, except Yakutat. Main aviation threat overnight will be any morning low level IFR cigs/visbys that develop under the ridge, but expecting those to diminish shortly through the early afternoon Tuesday as daytime heating gets underway.

A low near the Alaska Peninsula/Bristol Bay will send a front across the Gulf and into the panhandle through Tuesday afternoon, with flight conditions diminish at Yakutat down to MVFR by 14 to 18z Tuesday. Sustained winds increase up to 15kts with potential for gusts up to 30kts, left out LLWS for this TAF issuance as expecting surface SE-ly and 2k winds to parallel flow with speeds around 40kts max. Front extends eastward towards the Sitka, Gustavus, and Hoonah, with increasing potential for rain and increasing winds after 21z, reaching Juneau near 23z end of TAF cycle. Sustained winds increase through the afternoon around 10 to 20kts, with gusts up to 25kts, up to 30kts at Skagway and Yakutat. Will need to keep an eye on Skagway tomorrow afternoon as gradient tightens with front pushing inland, could see isolated gusts to 35 kts.

Thinking S Panhandle from Kake to Petersburg southward will see an extended period of VFR through the end of the TAF period, into late Tuesday evening as front primarily targets the N Panhandle.

MARINE

Outside: Coastal and Gulf winds have ranged between 15 to 25 kts NW-ly through the afternoon as ridging shifts eastward across the Gulf. Anticipating winds to shift W through the late evening with wave heights diminishing to 6 to 9 ft with swell becoming more SW-ly. By Tuesday morning, a 980 mb low near the AK Pen sends a front across the Gulf with winds turning SW-ly and barrier jet Gale formation from Icy Bay west to Cape Suckling. By Tuesday evening, winds across the Gulf remain SW-ly around 10 to 15kts, increased along the Gulf and SE-ly around 20kts.

Inside: Winds have remained around 15kts or less across the inner channels as pressure gradient diminishes, going near calm and variable overnight. Winds quickly increase through Tuesday afternoon with N/S channels as gradient tightens from arriving frontal passage. Strongest S-ly winds are expected in N Lynn, Taiya Inlet, and the upper arms of Glacier Bay, sustained near 25 kts with gusts up to 35 kts. Expecting these winds to slacken slightly but continue through the evening and into early Wednesday morning. Wave heights around 2 to 3 feet are expected within the inner channels, up to 4 feet in the aforementioned locations

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Frost Advisory from 2 AM to 7 AM AKDT Tuesday for AKZ319>321-325. MARINE...Gale Warning for PKZ652. Small Craft Advisory for PKZ012-022-053-641>644-651-661>664-671- 672.