textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

- A Wind Advisory remains in effect for the Anchorage Hillside and the Seward Highway along Turnagain Arm through 10AM this morning for wind gusts up to 55 mph. The Wind Advisory for west and south Anchorage has been CANCELED.

- Flood Watch remains in effect for Central/Western Susitna Valley from this morning through Friday morning, due to heavy rain.

Discussion:

A cloudy and wet morning over the western half of Southcentral and Kodiak Island as widespread rainfall in ongoing this morning. Satellite imagery shows a steady stream of moisture being drawn up from the North Pacific over Kodiak Island and up into the interior. The Bering low that has been driving this set-up is sitting over St. Matthew Island where is will wobble around as it weakens. Its front has generally stalled over the AKPEN and western Gulf as of this morning, and while it may still get nudged a bit further east, it will be weakening and washing out by Wednesday. A ridge of high pressure continues to dominate the eastern half of the Gulf, but will see its axis shift east over the Panhandle as a compact low moves into the southern Gulf. This low will continue to trek north on the periphery of the ridge before moving inland near Yakutat. However, with the ridge still firmly in place over the Gulf, dry air entrainment has been preventing good saturation to the surface across the Kenai Peninsula and Anchorage Bowl. This has resulted in less than efficient rainfall overnight. Recent model trends have also been cutting off the moisture transport earlier which will also result in lower rainfall amounts. Expect rain to start tapering off over the western Kenai Peninsula and up through the Mat Valley and becoming more showery by this afternoon. Modest rainfall still anticipated for the eastern Kenai where highest amounts will fall over the southern half. While heavier rainfall will be winding down by tomorrow, intermittent rain showers will continue through Friday.

Winds have decreased overnight for the western and southern areas of the Anchorage Bowl resulting in the Wind Advisory being canceled early; however, gusty winds are likely through mid-morning. A Wind Advisory remains in effect for the Anchorage Hillside as Winds still remain elevated early this morning, but should diminish by mid- morning as well.

- PP

LONG TERM FORECAST (Days 4 through 7: Friday through Monday)

To start out the longer term period, an upper-level low will remain in place across interior Alaska on Friday. This low moves off to the east across Yukon, Canada by Saturday. Aside from some scattered showers at times across the Southern Mainland, expect mostly quiet weather for Friday and Saturday.

The long-term forecast becomes more uncertain for Saturday and Sunday, especially for the Bering and Aleutians. The point of uncertainty arises with how guidance wants to handle upper-level energy coming out of Kamchatka. The Canadian and European suites want to develop this energy more than the GFS. Hence the GFS has a drier solution across the Aleutian Chain while the European and Canadian suites are wetter. Also of note, while the Canadian and European guidance does develop the Kamchatka energy, the resulting surface low is not expected to be strong at this time.

Across the Southern Mainland for Sunday, like the Bering, there is some uncertainty in the forecast. The Canadian and European suites take a shortwave moving out of the Arctic and keep it confined more to Northern Alaska which would be a drier solution for the Southern Alaska. The GFS, on the other hand, wants to dig this shortwave more to south and over Southern Alaska which would be a wetter solution for both Southwest and Southcentral Alaska for Sunday. For Monday, an upper-level low over interior Alaska moves south towards Southern Alaska. There does not look to be a lot of moisture with this system at this time and the likely outcome for Monday will be that this upper-level system helps to kick off some diurnally-forced showers across Southcentral and Southwest Alaska.

AVIATION

PANC...Strong southeasterly Turnagain Arm winds will continue to steadily relax this morning through early afternoon. Periods of steady light rain will continue to move over the terminal through this morning before tapering off by early this afternoon with ceilings expected to remain in the VFR range.