textproduct: Anchorage

LONG TERM FORECAST (Days 4 to 7, Saturday through Tuesday)

Going into the weekend, a longwave upper level trough will be over mainland Alaska with a deepening low at the base of the trough in the North Pacific. The low moves northeastward into the Gulf on Saturday, with guidance showing lowest surface pressure around 980 mb early Sunday morning. A tightening pressure gradient will promote small- craft to gale-force winds throughout the Gulf around the low, as well as accelerate gap winds in favorable areas (northwest winds through the AKPen, southeast winds in Turnagain Arm and Copper River Valley). Moisture pulled in from the Pacific will promote rainfall for the northern Gulf Coast through the weekend, with the heaviest rain expected Saturday night through Monday morning. Lighter rain may spill over into interior locations of Southcentral throughout the weekend, with highest chances in the Susitna Valley. Out west, persistent shortwaves will maintain overcast skies with occasional showers for Southwest, the Bering, the Aleutians and the AKPen through Monday morning. With the AKPen being closest to the low, chances for showers will be highest there.

Beginning Monday morning, a ridge looks to build in the Bering as longwave troughing continues over the mainland. Showers are expected to linger across Coastal Southcentral and parts of the AKPen, with some small craft winds possible through gaps in the AKPen as well given cold air advection on the west side of the low. Forecast confidence decreases Monday as models diverge on solutions. In general, models hint at the ridge slowly moving east on Tuesday to the eastern Bering. This may taper off lingering showers for the AKPen and Gulf Coast on Tuesday and promote quieter weather across Southern Alaska. Details will become more clear in the coming days.

- PA

AVIATION

PANC...Southeasterly winds will increase rapidly Tuesday morning, with gusts reaching 30 kt by 15Z and 40 kt by 20Z. VFR conditions will prevail initially, with light rain showers developing around 08Z. Ceilings will lower to MVFR by 20Z as steadier rain develops, with MVFR conditions persisting through the remainder of the TAF period. Winds become more southerly Tuesday evening while remaining gusty.

LM