textproduct: Anchorage

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

An active, progressive pattern continues through the end of the week and into early next week as multiple systems quickly track from west to east. This will generally bring periods of active weather, with brief lulls in between for most locations.

By Friday morning, a 990 mb low will have tracked just east of St. Laurence Island and begins to move inland near the Norton Sound, bringing moderate to heavy precipitation across much of southwestern Alaska. Concurrently, southwesterly small-craft to gale- force winds will continue to push into Bristol Bay and the Kuskokwim Delta coast. Widespread precipitation will also filter into Southcentral, and will be particularly heavy for the northern Gulf coast and Talkeetna Mountains. Turnagain/Knik gaps winds will likely return Friday, bringing potential for gusty conditions around Anchorage and Palmer. River levels across the Susitna Valley, such as the Yentna River at Lake Creek will have to be monitored closely with this system for potential flooding concerns.

By Saturday morning, the trough ejects a surface low into the Gulf, causing rainfall to taper off from west to east across the mainland as this low continues toward the Alaskan Panhandle. Some showers may linger in spots, particularly for Prince William Sound and the western/central Chugach, though conditions will gradually improve as ridging rebuilds over the region. A separate North Pacific low moves into the western bering by Saturday which will likely bring another wave of precipitation to the western/central Aleutians.

Deterministic solutions begin to differ substantially by Monday. However, ensemble means show a broad ridge amplifying just south of the Aleutians, which could set up a period of moist flow. Another shortwave appears to work down the mainland by Monday. If this feature can tap into this moisture, another round of widespread precipitation could be on track for much of the southern Alaska early next week.

-CW

AVIATION

PANC...Clouds will be on the increase this afternoon and evening as a frontal system advances toward the terminal from the west. VFR conditions will persist through tonight, although light rain is expected to develop by this evening. A southeasterly Turnagain Arm wind will develop overnight with these winds beginning to move over the terminal by early Tuesday morning. Sustained winds of 15 to 30 mph are likely along with gusts up to 40 mph. Occasional gusts of 45 to 50 mph are possible ( 30-40%) during the peak of the wind event, likely between 8 AM and 6 PM. Any heavier rainfall should hold off through the first half of Tuesday due to the these winds. However, steadier rain is expected by late Tuesday afternoon as the winds begin to diminish and the front moves into the area. MFVR cigs and vis are expected with this round of steady rainfall. There is a low chance ( 10-20%) that ceilings may fall to IFR in the wake of this system overnight Tuesday into early Wednesday morning as the wind flow aloft weakens.