textproduct: Anchorage

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

The progressive pattern looks to continue through late Tuesday or early Wednesday as multiple upper-level waves move southeast from the Chukchi Sea to the Alaska Panhandle. This will generally bring periods of active weather, with some lulls between systems.

The combination of cold air advection, a northwesterly low-level jet, and a shortwave trough through the northwesterly flow, will lead to and increase in northwesterly winds through the Barren Islands and around Kodiak Island/the AKPen, as well as northerly and westerly gap winds for Seward and Whittier by late Monday. Clouds and scattered showers will linger across portions of Southcentral Alaska as these waves move through, especially for the higher terrain and through the Copper River Basin.

Farther west, an upper-level ridge will build over the North Pacific, extending across the Aleutians, by late Monday. A warm front attached to a Kamchatka Low will move overtop the ridge and into the southern Bering for Tuesday morning. This feature looks to transition into an elongated surface low as it phases with a shortwave trough moving southeast through the Y-K Delta, brining more rain and gusty winds from Bristol Bay to Kodiak Island.

Model agreement then falls apart late Tuesday through Thursday. The biggest question will be how amplified the longwave pattern gets as the aforementioned ridge begins to extend north and east ahead of a deepening trough over the far western Aleutians. Most guidance is beginning to advertise a ridge axis moving over Southcentral with multiple upper-level waves and resultant surface lows moving into the western half of the Bering from the North Pacific. The surface fronts associated with these surface features look to move as far east as western Alaska Wednesday and Thursday with additional rounds of heavy rain and gusty south to southwest winds.

- TM

AVIATION

PANC...VFR conditions and light winds will persist through tonight. Rain is then expected to spread across the terminal tonight with periods of light to moderate rain showers Friday morning through Friday evening. The best chance for heavier rain showers will be after midnight through around 6 AM Friday and again Friday afternoon. MVFR ceilings and visibility are likely is any steadier rainfall. A strong southeasterly wind through Turnagain Arm will quickly develop this evening. These winds are expected to move over the terminal tonight and continue through Friday night before diminishing. Expect winds similar to those of two day's ago, with sustained SE winds 20 to 35 mph with gusts 35 to 50 mph.