Sitka, AK Weather

Synopsis

Key Messages:

- Onshore flow lasting will keep rain showers across the panhandle until Thursday before rain chances diminish and bring a drier trend going into the end of the week.

- Clearing skies and cooling trend to start out the weekend, with overnight temperatures dipping down into the low to mid 30s, and the northern panhandle possibly getting down into the upper 20s.

Long Term

/Friday through Sunday/... Benign days are ahead compared to the last week of strong systems for the panhandle. Friday sees the low pressure currently in the northern gulf finally fill completely, with another system moving up from the southwest. Not expecting this system to reach the southern panhandle fully, only expecting the extreme southern portion to be clipped by some moisture Saturday going into Sunday. Otherwise, expect to start out with mostly a cool trend, with overnight temperatures dipping down into the low to mid 30s, and the northern panhandle possibly getting down into the upper 20s. Could see some northerly winds increase out of Lynn Canal, but uncertainty in low strength and has lead to less winds for now.

Aviation

/through Thursday morning/

Remnants of strong front form yesterday continue to depart SE out of the AOR, leaving predominate VFR flight conditions in its wake with CIGS generally AoA 4000ft and unrestricted visbys. Behind the front, moving into a showery regime with hit or miss rain showers expected to impact the SEAK terminals through the TAF period as a low in the NE Gulf transits SE-ward and weakens through Wednesday night/early Thursday morning. With this regime, expect VFR flight conditions to prevail through the period, with likely reduced visibilities down to 2 to 4SM and gusty winds within any passing shower. Not seeing much lightning activity this morning, however could still see the occasional strike across the NE Gulf from Yakutat to Sitka, although high forecast confidence not as dense in coverage or intensity as yesterday. No LLWS expected through the TAF period. Winds remain around 10 kts or less through the day, outside of Skagway and Haines which will continue to see slightly stronger winds around 15 kts with gusts up to 25 kts possible into the afternoon before all terminal winds diminish overnight to near calm and variable after 09z Thursday.

Marine

Outside (Gulf and Coastal Waters): Conditions over the Gulf and outer coastal waters this morning continue to trend down for winds. Buoy observations show most places getting down to 20 kt or less with a few reporting less than 10 kt. The low pressure located near Prince William Sound will continue to bring onshore flow and showers for the next few days before weakening. Some of these showers could have a few rumbles of thunder but are not expected to be too significant. Main concern for the coastal and Gulf waters will be the elevated seas that are expected to continue for the next few days. WSW swell will continue to bring elevated seas before the swell influence decreases Thursday afternoon and we see wave heights start to diminish. Until then, seas are expected to be closer to 10 to 14 ft for today.

Inside (Inner Channels): Winds in the Inner channels this morning have dissipated significantly with most places down to 15 kt or less. A few places still are holding out with some 20 kt sustained winds that might persist through the day today. Otherwise, winds will continue to be on a downward trend for the next few days as the low currently located over Prince William Sound continues to weaken before high pressure builds in the Interior. With high pressure setting up in the Interior for the end of the week, offshore flow is expected to develop. At this time, wind speeds are not expected to be significant but this could change if a low pressure does pass south of the area for the weekend.