textproduct: Juneau

MID MORNING AND 18Z AVIATION UPDATE

The Freezing Fog Advisory for Yakutat has been cancelled. The dense fog has receded and visibility has improved this morning. Dense fog is still expected just offshore of Icy Cape this morning through the afternoon, staying predominantly over the marine areas to the west of Yakutat. Through the rest of this afternoon, dry conditions will continue under mostly clear skies with temperatures rising into the upper 20s to upper 30s across the panhandle. Next weather system on the horizon arrives by Sunday afternoon, bringing rain and snow back to the area.

LONG TERM

A pattern change emerges for the end of the weekend into next week, with our pleasant, but foggy, conditions giving way to onshore flow, snow/rain, and wind. Trying to keep things simple, a complex of systems in the west Pacific, fed by a stout jet and moisture from remnants of tropical storm Nokaen off the east coast of the Philippines, will merge they move toward the western Gulf of Alaska. Meanwhile a closed low forms over mainland Alaska, moving west toward the Russian coast by the end of the weekend. Expect southeasterly winds to become more organized in response to these systems late Sunday, with minimum gale force conditions anticipated for much of the coast, and seas increasing beyond 15 ft Tuesday, with a secondary low late Wednesday. One consequence of this pattern is moist onshore flow, which will contribute to snow impacts for areas north of Sitka/Angoon before a transition to rainfall occurs. For a much more detailed discussion, reference the hydrology section below; keeping things simple, expect 3 to 5 inches of snow at sea level for the Icy Strait Corridor (Hoonah, Gustavus, Juneau) and in northern Lynn Canal.

CPC guidance suggests overall warming temperatures next week with the more active weather, but due to the weakening outflow winds persisting in Lynn Canal, northern panhandle communities still have a chance to see this precipitation fall as snow before most likely changing over to rain by early next week. Precipitation still looks to remain on the lighter side of what is typical for Southeast Alaska, though continued onshore flow and another potential broad low following behind should keep relatively consistent precipitation in the forecast for next week.

AVIATION

/through 18z Sunday/ Benign conditions across the panhandle as outflow winds have diminished overnight, with the majority of the panhandle seeing VFR conditions and surface winds less than 10 kts throughout the TAF period. The NE Gulf Coast may still see some fog, but most is expected to stay offshore this morning. This fog is not looking as likely to impact Yakutat, until around 03z this evening where chances return for some VIS restriction and low stratus, with potential to drop from VFR down to IFR or lower. The outer coastline will begin to see some cloud cover move in early tomorrow morning from around 12z towards the end of the TAF period, with MVFR conditions associated with CIGs AoB 3000 ft, expected to start with Sitka and along Baranof and Chichagof Island along the outer coast and expected to move further inland from W to E just beyond the TAF period. Winds are expected to shift for these areas as the front moves in from a weak northerly offshore flow to a SE-ly direction, though winds are expected to stay calm and below 10 kts through 18z tomorrow morning.

MARINE

Inner Channels: Winds across the northern inner channels have subsided as the pressure gradient has collapsed. Through the day on Saturday, expect winds to remain fairly light, with most areas seeing winds in the 5-10 kt range. Waveheights remain ~3 ft or less through this time frame, with the exception of ocean entrances, where higher wave heights are possible. Conditions begin to deteriorate Sunday night, as a front moves into the panhandle, bringing increasingly strong winds and elevated seas.

Outer Coastal Waters: Through Saturday, winds of ~5-15 kt are expected, with seas generally remaining ~3-5 ft. Conditions will deteriorate on Sunday as a front works it way across the Gulf of AK, with winds approaching 20-25 kt for the outer coastal waters by Sunday night.

AJK WATCHES/WARNINGS/ADVISORIES

PUBLIC...None. MARINE...