textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

A series of upper-level shortwaves continues to move inland from the northern Gulf helping to enhance shower activity along a stalled and weakening front draped along the coast. Temperatures have warmed into to the mid 30s to lower 40s for locations along coastal Prince William Sound and eastern Kenai, allowing for the precipitation to fall as rain. Father inland, temperatures are in the teens in the Copper River Basin and 20s and 30s from Homer north into the Mat-Su Valleys. Any precipitation that is making it over the coastal mountains is falling, and will continue to fall, as a very light wintry mix. Snow levels are currently around 2,000 ft.

The forecast looks on track a much stronger front will lift across the Gulf tonight into Tuesday morning with models developing a second surface low just off the southern coast of Kodiak Island by mid-morning Tuesday. The pressure gradient will rapidly strengthen over the western Gulf with widespread gales and a swath of storm force winds developing by Tuesday morning from Middleton Island to the Barren Islands and Shelikof Strait. This east-northeast oriented swath of strong winds is an ideal direction to see strong winds across parts of Kodiak Island. Wind gusts up to 60 mph will work across the northern end of Kodiak Island, with typical spots helping to channel the winds. In addition, the warm and moist airmass will bring periods of moderate to heavy rainfall for Kodiak Island. Modest rainfall amounts are also expected for the immediate Gulf coastal areas along the eastern Kenai Peninsula.

Lee-side areas north and west of the coastal mountains continue to look mostly downsloped with a dry northerly wind through Tuesday, likely keeping any freezing rain in the morning hours to just a few scattered sprinkles. By Tuesday evening, however, flow aloft will become more southerly and some stronger shortwaves moving over should be enough to kick some light rain into the western Kenai, Anchorage, and potentially the Mat-Su Valleys. Warmer air will also likely push into Valdez and the southern half of the Copper River Basin by tomorrow afternoon, allowing any snow to mix with and change to rain for Valdez and, perhaps, a wintry mix along the Edgerton Highway.

The warm and wet pattern along the coast will continue through the week as multiple storms move through. Well above normal temperatures will continue everywhere in Southcentral.

- TM/CJ

LONG TERM FORECAST (Days 4 through 7 - Friday through Monday)

Late this week, the upper-level longwave pattern appears fairly similar to today with a ridge over western North America extending up into mainland Alaska with a broad, complex low pressure system sitting several hundred miles south of Kodiak Island. The main difference will be that deep longwave troughing over the far western Bering Sea will promote a much stormier pattern heading into the weekend and early next week. The complex low south of Kodiak Island lifts into the Gulf through the weekend, bringing wet, rainy weather along the coast from the Pacific side of the Alaska Peninsula up to the north Gulf coast. A deformation band associated with troughing to the north/northwest of the low may allow precipitation to spread into the southern mainland in the form of rain, freezing rain, or possibly snow for the coldest locations.

The main feature to track in the long term, however, is a compact, moderately-deep low moving up from the North Pacific into the vicinity of the eastern Aleutians/Alaska Peninsula on Sunday. This low, depending on track, could lead to various hazards across the Aleutians, Bering Sea, and Southwest Alaska, including high winds and blowing snow/blizzard conditions. Strong winds will be associated with a sting jet on the south side of the low, which has the potential to bring 75 mph wind gusts to the Eastern Aleutians and Alaska Peninsula if the track shown by the EC and GEM verifies. However, the alternative solution shown by the GFS keeps the low south of the peninsula, which would spare the region from the strongest winds and impacts. There is a decent potential for the low to track into the Bering Sea, though, towards Southwest Alaska. The low looks to quickly lose its tap of warm air as it moves north, which means precipitation mainly in the form of snow along the Southwest Alaska coast would be easily blown around leading to significantly reduced visibility. As the track is uncertain at this point, there is low confidence in the resulting impacts at this lead time. The active storm track continues into next week with another compact low developing south of the Aleutians on Monday, with further potential to skirt the Aleutians or track north into the Bering Sea.

Quesada

AVIATION

PANC...VFR conditions are expected to continue through the period...though a few brief drops to MVFR are possible as elevated showers pass through this afternoon and evening. Another round of showers expected Tuesday afternoon and evening with a stronger front lifting north over the terminal. Near freezing temperatures today will rise above freezing by Tuesday, mitigating any light freezing rain concerns with any showers passing over the terminal. North to northeasterly winds will increase by 12-15Z Tuesday morning ahead of the incoming front.