textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

- Another cold night is expected again Wed morning, especially for coldest prone locations (Butte, Muldoon, Campbell Tract, and the Eagle River Valley) with temperatures approaching freezing. Temperatures will depend on cloud cover. The main concern is for cold and frost sensitive outdoor plants/vegetation. The Frost Advisory was extended for an additional night. A trend toward seasonable temperatures is expected for the last half of the week. - Gusty offshore winds continue over the next few days with the strongest winds along the coast and through gaps and passes.

Discussion:

Isolated pockets of cold temperatures were observed this morning for coldest prone locations in the western Kenai Peninsula, Anchorage, and Matanuska Valley. The frost advisory will remain in effect until 9AM AKDT Wednesday. Frost and colder than normal temperatures will continue to be a concern for sensitive outdoor plants. Protect, move, or cover those plants for an additional morning should skies be clear during the coldest part of the morning. Frost potential will depend on cloud cover. If conditions stay more on the clear side, the airmass looks to be very similar to tonight/early Tuesday morning with more frost potential. If there are more clouds present, this will prevent radiational cooling from fully taking effect and thus lower frost potential. Temperatures look to trend to more seasonable temperatures Thursday onward as a ridge will start to build and high clouds start to filter across Southcentral.

Gap winds, but especially through Whittier and Seward, will remain elevated for the next few days as flow will remain out of the northwest. Gusts may relent somewhat this afternoon near Seward as the low in the eastern Gulf moves onto the North Pacific and higher pressure builds across the area. The sea breezes may briefly shift winds during the warmest part of this afternoon for coastal communities, but northerly offshore winds will prevail by this evening.

For Wednesday, a shortwave digs south from Central Alaska to northeastern portions of the Copper River Basin. This feature will be pretty moisture starved, but a few showers are not out of the question for Wednesday afternoon. A strong upper-level ridge builds in for Thursday as all of Southcentral remains dry. The next weather system to watch will come from the Bering Friday and this weekend as the pattern will switches from dry to wet. Models differ with the onset timing of its arrival. The earliest spill over could begin as early as Thursday night.

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

The long-term period looks to remain active, especially across Southwest Alaska, the Bering Sea, and the Aleutian Chain. With a ridge axis anchored over Southcentral and the Gulf of Alaska, and a complex low pressure system spinning about in the central Bering Sea, Southwest Alaska appears to be the more active of the areas.

Across Southcentral Alaska, the ridge will be overhead for much of Friday with relatively quiet weather anticipated. The ridge moves east to the eastern Gulf of Alaska and into Yukon, Canada Friday evening which will open the door to southwest flow aloft. Steady rain from Southwest will move into Southcentral through late Friday as a plethora of shortwaves lift up and over the area from North Pacific and Gulf. Showers continue over Southwest, the Aleutian Chain, and Southcentral for Saturday as a broad upper- level trough remains in the Bering and southwest flow aloft remains across Southcentral.

A series of several shortwaves spinning around the complex low in the Bering will move from the Bering into Southwest Alaska Friday and Saturday. By late Saturday, a compact low entering from the northern Gulf will enter the southeastern Bering Sea with the chance to swing into Southwest Alaska. Model agreement is poor regarding the progression of this feature, however it may bring a more condensed push of rainfall into the area. Also, depending on the orientation of the southwest winds into Southwest Alaska, coastal concerns in the Kuskokwim Delta remain present as a possibility, but we will continue to monitor it's progress.

-CL

AVIATION

PANC...VFR with light winds throughout the TAF period.