textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

Discussion:

Overnight remain quiet with any final showers dissipating and many areas seeing a period of clear to mostly clear skies which allowed temperatures to fall into the upper 20s to mid 30s for many areas across Southcentral. By early this morning, mid and high clouds have begun to push into Southcentral preventing temperatures from falling further and lowering fog potential along the mid and upper Cook Inlet areas. Radar is also picking up on the increasing cloud cover over Cook Inlet and the southern Kenai Peninsula. Meanwhile, satellite imagery shows today's weather disturbance starting to pivot more north as it cross the AKPEN and makes its way towards the Bristol Bay area later today. Rain and mountain snow showers will begin to fill in across Kodiak Island later this morning, then up along the eastern Kenai Peninsula and the western Susitna Valley by this afternoon. This will be the first in a series of systems that will lift up through Southcentral over the next several days.

These systems will have a good fetch of moisture transport northwards allowing for a period of moderate to heavy rain for coastal locations of the Kenai Peninsula, Prince William Sound, and the northern Gulf Coast from today through Saturday where up to several inches of rainfall can be expected. For higher elevations, moderate to heavy snow can be expected with strong ridgetop winds and snow levels increasing from about 800-1200 ft to 1200-2500 ft by Saturday. Increasing easterly winds across the Chugach and Kenai Mountains will help to downslope much of the western Kenai Peninsula, Anchorage Bowl, and lower Mat-Su Valley keeping these areas mostly dry.

With strong easterly flow and increasing pressure gradient over the Chugach Mountains, allowing for strong Turnagain Arm, Knik, and Copper Valley winds to develop. The winds will start to increase later today, peaking on Friday, then decreasing Friday night into Saturday. The core of the strongest winds will remain out over the Arm itself while some southeast winds make it into town this afternoon. Flow bends further down- inlet beginning early Friday morning with a return to northeast winds across the Anchorage Bowl. However, southeast winds return across the Bowl Friday afternoon and persist into Saturday. The Anchorage and Eagle River Hillside will also see gusty southeast winds, potentially up to 50 mph Thursday night into Friday. The Knik and Copper Valleys will also see gusty southeast winds Thursday through Saturday.

Another shortwave lifts through the Gulf Saturday afternoon and evening. This will bring another shot of moisture to Kodiak Island, the northern Gulf Coast, and Prince William Sound. Sunday brings another shot of precipitation to the northern Gulf coast with the bulk of the precipitation looking to be more focused on eastern Prince William Sound and northern Gulf Coast, including Cordova; however, models have some slight differences to work out over the next few days with this late weekend system.

- PP/DAN

LONG TERM FORECAST (Days 4 through 7: Sunday through Wednesday)

Upper level high pressure over the western Gulf and and low pressure over the eastern Bering Sea will keep Southcentral Alaska in an active storm track at the start of the long term forecast period. Reinforcing shortwave troughs and associated surface features will send a waves of moisture across southern Alaska Sunday through Tuesday. Model agreement regarding exact timing and placement is poor at this time, but most global models depict a low pressure system moving into the western Gulf on Tuesday, increasing chances for winds up to gale-force in nearby waters. Things get messy beyond this, with the one thing models agreeing on is low pressure in the western Bering Sea by Wednesday. There are hints of high pressure redeveloping in the Gulf by this time, but exact placement will greatly influence weather for Southcentral. Stay tuned as things become clearer in the coming days!

AVIATION

PANC...VFR conditions persist. Turnagain Arm winds increase from the late morning through the afternoon.