textproduct: Fairbanks

SYNOPSIS

Clear skies, light winds, and seasonable temperatures continue across the majority of our area Sunday. On Monday, a system arriving in the Gulf of Alaska will cause light, wrap-around precipitation in the southeast Interior and eastern Alaska Range. Scattered flurries are possible in the southwest Interior on Monday, ahead of a more substantial front arriving in the YK Delta Monday night. This system brings widespread precipitation to the YK Delta and Western Interior on Tuesday which should begin as snow, but turn to a rain/snow mixture as temperatures warm above freezing Tuesday afternoon. Light mixed precipitation continues east into the Interior on Wednesday. In the latter half of the week, calmer conditions look to return, with chances for another round of precipitation in the West by next weekend.

FORECAST ANALYSIS AND DISCUSSION

We begin Sunday morning with a 548 decameter high over Mackenzie Bay and a 525 dam low over the YK Delta. This pattern is resulting in clear and calm conditions across the majority of Northern Alaska. However, the low over the YK Delta becomes diagonally stretched, extending from the Gulf of Alaska to the Bering Strait Sunday night. The part of the upper low that that drops into the Gulf becomes stacked on top of a deepening 1012 millibar surface low moving north, pulling moisture along with it. As a result, we see wrap-around precipitation make it up into the southeast Interior Sunday night into Monday. Parts of the Tanana Valley southeast of Delta Junction will see up to an inch of snow through Monday. We may see scattered snow flurries in the southwest Interior as well on Monday, as an upper-level ridge over the Bering pushes the remnants of the YK Delta low farther inland.

Coming in from the southwest behind that ridge is a warm front. A series of lows from the north Pacific are pulling warm moist air up from the tropics. That moisture will be arriving in Southwest Alaska sometime Monday evening. Initially, the precipitation type should be predominantly snow, as temperatures in the YK Delta and southeast Interior remain at or below freezing through Tuesday morning. However, it should transition to rain or a rain/snow mix as temperatures rise Tuesday afternoon. the front continues north into the Western Interior and Seward Peninsula on Tuesday. High pressure pulls a good portion of the moisture towards Anchorage and the rest of South Central Alaska, reducing the overall impact on Western Alaska.

Winds behind the front will be easterly and gusting into the mid 20s for areas in the YK Delta and likely above 30 mph for areas along the Coast and for St. Lawrence Island. Southerly winds through the eastern Alaska Range swell Tuesday, up to 40 mph.

EXTENDED FORECAST DAYS 4-7

At the start of the extended, on Wednesday, the front from the southwest will continue eastward into the Interior, providing slight chances for mixed precipitation. High pressure quickly reestablishes itself over mainland Alaska in the wake of this system. Ensemble models are in relatively good agreement on keeping this high pressure anchored over Alaska. As a result, another low moving into the Bering on Friday takes a northerly track through the Bering Strait. Precipitation should be limited to the West Coast, and the gradient between the low and the high pressure over Alaska creates strong southerly winds through the strait.

Uncertainty surrounds exactly how much precipitation will move from Western Alaska further northeast, with overall accumulations regionwide expected to remain light. Warmer temperatures will accompany this front as most locations south of the far northern Arctic Coast see highs build well into the 30s to mid 40s with overnight in the teens/20s.

The overall pattern change appears to shift high pressure farther east from the Bering to mainland Alaska, potentially allowing weak systems to travel up along the West Coast more easily.

Coastal Hazard Potential Days 3 and 4...None

AFG WATCHES/WARNINGS/ADVISORIES

AK...None. PK...Brisk Wind Advisory for PKZ851.