textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

With the dissipation of today's round of showers this afternoon, expect a brief break in the rain ahead of a more significant rainfall event to affect Southcentral through the remainder of the weekend. The forecast remains on track, with a deep and amplified upper low set to bring an atmospheric river to portions of Southcentral over the weekend and into next week. Ahead of the system, the coastal ridge will continue to build through this evening leading to increasing gap winds. The winds will be similar (though slightly weaker) to the wind event earlier this week. Tonight the main plume of moisture will arrive with deep south- southeast flow aloft. With this flow direction, and a few embedded shortwaves, the eastern Kenai Peninsula and western Susitna Valley will be favored for moderate to heavy rainfall. Seward will likely receive the most, with 4 to 6 inches of rain expected through Monday evening. Anchorage will have some downsloping, but perturbations moving through the southerly flow may bring periods of light rain, especially in this moist environment. Ridging farther to the east will help to keep the Copper Valley dry with warmer temperatures.

By Tuesday the upper trough will take on a negative tilt and begin to move east, spreading moisture to the rest of Southcentral on Tuesday. Looking ahead, more of the same. Rain.

SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)

The low in Bristol Bay will continue to bring onshore flow and rain showers to the Mainland and AK Pen into Sunday evening as it slowly moves onshore this weekend. Also, persistent northerly flow in the Central Aleutians and northwest flow in the Western Aleutians results in continued wind gusts ranging from 35 to 45 mph through the weekend.

As the low moves onshore and a Bering Strait low forms Monday, a more pronounced trough pattern begins to form in the Bering Sea. This brings multiple waves of moisture through Bering Sea / Bristol Bay. The first of these waves slides a weak low southeastward from Russia Monday morning reaching just north of the Pribilof Islands by Monday afternoon. It brings a resurgence of precipitation and winds to the Central Aleutians and Pribilof Islands by this time. The front then reaches the Mainland Coast Monday evening with rain and onshore S/SE winds. This coincides with low tide. The trough will also bring continued waves of moisture through the Western Aleutians resulting in continued showers through mid-week.

-Johnston

AVIATION

PANC...Widespread rain showers are expected. There could be a brief period of decreased shower activity this afternoon and evening when gusty southeasterly winds from Turnagain Arm move across the airport. VFR to MVFR ceilings are expected with rainfall. By 08Z, northerly flow will bend Turnagain Arm winds down-Inlet. At that time, low-level wind shear appears more probable as southeast winds continue across the Chugach Mountains, while surface winds over the airport become light and northerly. This could last through at least Sunday afternoon.