textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Discussion:

The vertically stacked low continues to spin in the central Gulf as it slowly progresses northeastwards towards Southeast Alaska through the weekend. The diminishing of showers along the coast early this afternoon will be short-lived as the next shortwave trough rotating along the northern periphery of the low reaches the Gulf coast by late this afternoon. Shower coverage is expected to pick back up through Saturday morning for the northern Gulf coast and Prince William Sound with the arrival of the shortwave and as the low center nears the coast. Any lingering chances of precipitation for inland areas continues to decrease through this evening, with mainly dry conditions expected through Sunday as off-shore flow takes over. Snow levels will stay fairly consistent around 2500' as the low translates across the Gulf, so will still see rain changing over to snow at higher elevations while showers still persist.

A weak front will move across the Alaska interior Saturday morning. Colder northwesterly flow will help to dry things out, but models are hinting that the front could squeeze out some light precipitation of the Upper Susitna and Copper Basin. However, overall confidence is low (20-40%) that any precipitation out of this frontal passage will amount to anything too impactful. Cooler temperatures will move in behind this system with low temperatures dropping into the teens and 20s for most of inland Southcentral for Sunday morning.

Looking ahead to early next week, a Bering Sea low will send its front into the Gulf, bringing an uptick in winds across the Gulf and along the coast for Monday. Model spread remains fairly high with regards to a potential triple-point low spinning up in the Gulf, but expect precipitation to begin to overspread Kodiak Island and the eastern Kenai by early Monday.

-JH/PP

LONG TERM FORECAST (Days 4 through 7: Tuesday through Friday)

The seasonably active weather pattern in the Gulf continues through the long term period, with a fairly inactive pattern poised for the Bering. By Tuesday morning, a decaying surface low along the northern Gulf coastline will continue to bring gusty easterly winds and rain to the area. For the Alaska Peninsula, Bristol Bay, and inland Southcentral locations, expect unsettled and showery weather to continue through early next week as weak shortwaves rotate through the upper level flow. Additionally, gusty northerly winds enhanced by cold air advection on the back side of the low will be possible across the eastern Aleutian Islands and AK Peninsula, especially through favored gaps and passes.

By mid to late next week, a more impactful storm is expected to build in the southern Gulf/northern Pacific, entering our area south of the Alaska Peninsula. Widespread rainfall and strengthening winds are expected to spread across the Gulf of Alaska including Kodiak Island. In the Bering by Wednesday afternoon, there is quite a large spread in model solutions, with the GFS suggesting a 995 mb gale-force low over the Central Aleutians, and the Canadian and EC solutions suggesting a 1024 mb ridge blocking all active weather in the area at that time. By Thursday, this contended low may shift into the Gulf, bringing another round of winds and rain to Southcentral, while other solutions are spreading the high pressure ridge at that time. Both solutions suggest a new frontal system entering the westernmost Bering/Aleutians by Thursday afternoon into Friday morning. Stay tuned as we continue to monitor this system and the progression of guidance.

AVIATION

PANC...VFR conditions and light winds will persist through this evening. Cooling temperatures and clearing skies overnight could allow for formation of low stratus late tonight into Saturday morning, possibly bringing ceilings into MVFR range or lower. Confidence in the development of low stratus is still relatively low, and low cloud formation will depend on the degree of clearing of upper level cloud cover tonight into early Saturday.