Marine Weather and Tide Forecast for Newhalen, AK

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3/Tonight through Thursday)...

A very stable pattern will lead to continued cold and windy conditions across the eastern Bering Sea and into portions of Southwest AK the next few days. Perhaps more impactful, conditions are perfect for large areas of extreme vessel icing across Southwest AK coastal waters. Taking a look at satellite imagery, a strong high amplitude blocking ridge is centered over the western Aleutians and covers much of the western Bering Sea. Deep and strong northerly flow east of the ridge is maintaining a bitter cold airmass across the eastern Bering Sea and Southwest AK. Gusty northerly winds can be found across the eastern Bering and down across the eastern Aleutians (Nikolski, Dutch Harbor, Akutan) and southern Alaska Peninsula (False Pass, King Cove, Sand Point), Satellite-based freezing spray imagery shows extensive freezing spray across marine areas along the Alaska Peninsula. Cold Weather Advisories remain in effect along the southern Alaska Peninsula for wind chills as low as 10 below zero. Winds have lightened up across the rest of Southwest Alaska, so wind chills are no longer a big factor. However, temperatures are well below normal for this time of year, ranging from around zero to 10 degrees above zero. Lastly, a short-wave trough tracking down the east side of the ridge is bringing snow showers and enhanced winds to the Pribilof Island and central to eastern Bering Sea this afternoon.

The upper level ridge will remain nearly stationary through Thursday, resulting in very persistent weather conditions across the region. The primary cause of fluctuations in the forecast will be short-waves tracking southward across western AK and the eastern Bering Sea. The short-wave in the Bering this afternoon will move to the eastern Aleutians (Dutch Harbor area) and southern Alaska Peninsula this evening, bringing a period of steady snow showers and strong, gusty winds. This will exit to the North Pacific by early Tuesday morning, but a reinforcing shot of cold air advection behind it will produce snow showers off the ice edge and down to the Eastern Aleutians/Alaska Peninsula. A secondary fast moving upper level short-wave combined with the low level cold air advection will strengthen gap winds along the Alaska Peninsula and lead to expansion of marine areas covered by heavy freezing spray and extreme freezing spray (potential for 4cm/hour or greater icing rates). Sub-zero degree wind chills will persist across the Alaska Peninsula, where Cold Weather Advisories remain in effect all the way through Wednesday.

Another short-wave will ride over top of the ridge and across the northern Bering Sea Wednesday before diving southward Wednesday night through Thursday. This will bring snow to portions of the Kuskokwim Delta and down across the eastern Bering Sea to the Alaska Peninsula. The airmass behind this doesn't look nearly as cold as what is in place right now and over the next couple days.
Thus, winds will be weaker, temperatures/wind chills more moderate, and there will be less heavy freezing spray for marine areas.

-SEB

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

The long-term outlook suggests a complex atmospheric setup. An upper-level trough centered over the northern Gulf of Alaska will stretch southward into the North Pacific, serving as a hub for several rotating shortwaves. While high pressure is expected to dominate the Bering Sea through Sunday, the weather will shift by Monday afternoon as an upper-level low arrives, bringing snow showers to the western mainland.

Regarding local impacts, a tightening pressure gradient along the coast will trigger intense winds through the gaps of the North Gulf Coast. Additionally, strong northerly flow and cold air advection will lead to gusty gap winds and frigid conditions across the Alaskan Peninsula. Model guidance is generally in good agreement in this pattern that will keep temperatures well below seasonal norms for both South and Southcentral Alaska through the end of the forecast period.

AVIATION

PANC...VFR conditions and northerly winds will persist through the TAF period. The northerly winds are expected to increase this evening in conjunction with colder air moving into the region.