Marine Weather and Tide Forecast for Juneau, AK

UPDATE
Mainly for Aviation and short term. Thunderstorm development southern part of panhandle with a lobe of vorticity moving into the south central panhandle this afternoon to early evening hours.



PREV DISCUSSION
ISSUED AT 644 AM Mon Jun 16 ...

SHORT TERM
A closed upper level low is currently sitting west of Haida Gwaii and will be moving northwest along the coast of the panhandle through Monday. The associated deeper trough tipped negatively overnight, which sent a 1000 mb surface low following up the coast of the panhandle. Currently, this low is off the western coast of PoW Island, and the attached gale force front is bringing increased winds and rain to the southern panhandle. Wind speeds along the coast will be enhanced by higher pressure along the coast mountains, increasing wind speeds to near gale or gale force. Additionally, the cooler air associated with the occluded front will descend to the surface, resulting in a strong, gusty jet with wind gusts as high as 45 knots. Therefore, gulf wind speeds have been raised to gale force (34-40 kts) through the day, with severe gale force wind gusts possible. Coastal communities may see land wind gusts up to 30 mph, with strongest speeds expected between 10 am Monday morning to 5 pm Monday evening. A band of precipitation is moving north over the panhandle, bringing light to moderate rain rates for up to 6 hours before transitioning to possible scattered showers behind the front.
Conditions are set to gradually improve through Monday, with precipitation looking to lighten up for the southern panhandle as it reaches the northern panhandle through the morning.
Precipitation should finish for the northern panhandle through the afternoon with only minimal accumulations expected.

LONG TERM
/Tuesday into next weekend/...
Rain continues for primarily the southern portion of the panhandle Tuesday before showers move up across the rest of the panhandle Wednesday into Thursday. These easterly showers are associated with waves moving around a weak low to the southwest in the Gulf around 140W. These showers will begin to decrease into Thursday night as a surface ridge begins to approach the panhandle, pushing the weakening low to the southeast. This ridge, accompanied by an upper level ridge building over the Gulf on Friday, will help to bring drier weather, clearer skies, and some higher temperatures into this weekend. Models showing 850mb temperatures of between 10 and 12 degrees C moving into the area alongside this ridge, which will bring us some warm air advection that will also aid in bringing temperatures up. This warm air advection alongside the surface ridging will bring some areas of the panhandle to over 70 degrees for their highs this weekend, with the highest temperatures looking to be Saturday afternoon.

Winds are expected to stay light in the majority of the panhandle midweek, with the exception of winds moving into Clarence Strait remaining elevated into Wednesday as the low to the southwest continues to bring southerly winds. Winds look to stay on the lighter side over the region for late in the week into the weekend. However, the pressure gradient in the northern panhandle may tighten as the ridge begins to move in while a low remains over Canada to the northeast, which may bring some elevated winds to Lynn Canal on Thursday.

AVIATION

Predominate VFR flight conditions across the panhandle this morning with CIGs AoA 4000ft.

Through the rest of the day, anticipating general MVFR to VFR flight conditions to prevail with CIGS AoB 5000ft and reduced visbys 3 to 5 SM through the afternoon within heavier precip as a front pushes into the southern panhandle and overspreads the area. Main aviation concern through the afternoon will be increasing LLWS up to 30kts near 2000ft for the southern and coastal TAF sites, particular Ketchikan, Klawock, and Sitka, through early Monday morning, decreasing through 00z. Winds for the southern panhandle TAF sites will increase through the morning and into the afternoon, with strongest overland winds around 15kts sustained with gusts up to 25kts likely. For the northern panhandle, expecting slightly less wind, around 10 to 15kts kts, but can't rule out an isolated gust this afternoon up to 25kts as front pushes through.

Gradual improvement to predominate VFR flight conditions 06z this evening as front exits the panhandle.

MARINE

Outside Waters: Wind speeds have been raised in the eastern gulf to gale force (34-40 kts) through the day, with severe gale force wind gusts expected in the eastern gulf off the coast of Prince of Wales and Baranof Islands. Widespread fresh to strong breezes (17-27 knots) will persist along the coast through midnight. Wave heights do not look to exceed 11 ft due to lack of sufficient fetch length and time for more developed seas. Small craft advisories follow the front offshore up the coast through the day, with gale warnings persisting through Monday evening.

Inside waters: Strong breezes coming in from Dixon Entrance will move up Clarence Strait and into Sumner Strait. As the low continues to move northward near Sitka, inner channel winds will increase slightly with some areas reaching sustained moderate breezes. Winds in the central & northern panhandle will switch southerly as the low tracks further north. Coastal entrances such as Southern Chatham Strait, Clarence Strait, and Cross Sound may see fresh to strong sustained breezes with near gale force gusts when the front passes over through Monday afternoon. These may also be associated with elevated wave heights of up to 7 ft. There is a small craft advisory in Chatham Strait that persists through Monday afternoon.

AJK WATCHES/WARNINGS/ADVISORIES
PUBLIC...None.
MARINE...Gale Warning for PKZ661>663.
Small Craft Advisory for PKZ036-641>644-664-671-672.