textproduct: Juneau

UPDATE

Update to the Aviation Section to include the 06z TAFs.

PREV DISCUSSION......ISSUED AT 322 PM AKDT Thu May 7

SYNOPSIS... - Enjoy the break Thursday afternoon. Rain and wind return for the weekend. - Periods of gale force conditions are likely along the coast over the weekend. See Marine Section for further info.

SHORT TERM...

Going into further detail, low clouds and some light rain was the theme early Thursday, but in general we are seeing excellent clearing from a building surface high in the eastern gulf, with winds diminishing as the pressure gradient relaxed. Our summer time weather comes crashing to an end Friday as a unseasonably strong storm lifts into the Gulf over the weekend, bringing wind and a few inches of rain to the region. For timing, expect the first wave of light rain to impact the central and southern Panhandle by Friday morning, lifting north through the afternoon. Friday evening moderate to heavy rainfall quickly advances across the Panhandle, with rainfall persisting into Sunday. For folks along the coast, expect the strongest winds, with periods of gale force conditions. See marine section for further detail.

LONG TERM.../Sunday through Tuesday/... Rain continues across the panhandle as we move out of the weekend and into the week. However, rain rates appear to be lightening up from moderate and persistent to light and showery over the day Sunday. There could be periods of heavier showers on the inner eastern part of the panhandle -- Juneau, Petersburg, Wrangell -- through the day Monday. Winds across the panhandle continue to diminish through the day Sunday as the low jumps onto land in the western gulf. High winds from channeling the previous day have the potential to linger in the inner channels across the panhandle with models picking up on Stephens Passage in particular. At the same time, winds in Lynn Canal look to increase through the day Sunday and be sustained around 20 mph as the pressure gradient over the panhandle squeezes.

AVIATION.../through 06z Saturday/...VFR conditions continue for the panhandle with some occasional MVFR ceilings being reporting at times in Yakutat. MVFR conditions are expected to become more prevalent across the panhandle as a low moving north into the Gulf of Alaska will bring reductions in ceilings and visibilities starting during the morning hours for the southern panhandle before spreading north. Ceiling heights are expected to be around 2,500-3,500ft as conditions diminish. Locations farther to the north will see either a delayed onset or potentially less significant ceiling reductions for places like Skagway. With the incoming rain and winds, some visibility reductions are possible as well visibilities dropping down to around 4-5 SM. Another concern will be the LLWS as this system moves north. Currently the far southern TAFs reflect this but it is expected to move north tomorrow into tomorrow evening.

MARINE... Outside (Gulf and Coastal waters): Simply put, periods of near-gale to gale force easterly to southeasterly winds impact the majority of our coast Friday afternoon into the weekend, with seas building to 15 to 18 ft.

Further info: Thursday morning, buoy systems and satellite derived wind/altimeter passes show gentle to moderate breezes across the central Gulf and diminishing seas of 4 to 6 ft. Expecting these conditions to stick around Thursday afternoon, before an unseasonably strong gale force system starts to lift north into the Gulf, impacting the weekend.

Expect winds to become southeast through Thursday evening, slowly increasing to moderate to fresh breezes. Friday morning winds will be easterly fresh breezes along the majority of our coast before a front associated with the low lifts through the eastern gulf, bringing a few hours of near-gale to gale force SE winds. Regarding timing, expect these frontal winds to reach the Prince of Wales coast by 2 to 4 pm Friday, Sitka Sound by 3 to 5 pm, and the Fairweather Range by 6 to 9 pm. After the frontal passage, southeast winds of strong breezes persist for the majority of our coast, with a more extensive period of near-gale to gale force winds for our coast Saturday late morning. Associated with this system is an excellent dynamic fetch responsible for southerly swell, along with the aforementioned fetch of southeasterly winds generating large southeasterly wind waves along the coast. Expect large and confused seas of 15 ft, to potentially as high as 18 ft, along the majority of our coast, with the focus of wave energy from the Fairweather Grounds to Cape St. Elias.

Inside: Light winds remain the theme Thursday afternoon for the inside, with the exception of a few locales like Clarence Strait and Lynn Canal that are seeing some organized winds of moderate breezes. Primary threat remains Friday through the weekend as a gale force low pushes into the central Gulf, driving southeasterly winds through many channels. Given the low location, major east- west channels and passages like Icy Strait, Peril Strait, and Clarence Strait (to name a few) will see the strongest winds. By and large, expect sustained winds of strong breezes for many locations, with some favored areas (like Snow Passage in Clarence) seeing a few hours of near-gale force conditions Friday afternoon. Southerly winds of fresh breezes to strong breezes continues across many central and southern inner channels Saturday.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...Wind Advisory from 4 AM to 1 PM AKDT Saturday for AKZ332. MARINE...Gale Warning for PKZ644-652-664-671-672. Small Craft Advisory for PKZ031>033-035-036-053-641>643-651- 661>663.