textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Key Messages:

- A large storm system will bring widespread rain and snow to most of Southcentral tonight through Tuesday night.

Discussion:

Abundant cloud cover is over a good portion of the state this morning. Despite cold air advection behind the trough the moved through yesterday, the cloud cover has prevented many areas from dropping into the 20s this morning. A few lingering showers were still ongoing over the southern Cook Inlet area associated with a weak surface low and trough. This activity should diminish through late morning. The rest of of Southcentral should see some peeks of sunlight by this afternoon before clouds overspread the region tonight.

The next system is already taking shape as the low deepens over the Bering Sea and the front lifts up across the AKPEN, Kodiak Island, and the western Gulf through this afternoon. Widespread precipitation will follow behind the front...first across the AKPEN and Kodiak Island before spreading north across the Kenai Peninsula, Susitna Valley, and Prince William Sound. Some downsloping may limit precipitation for a bit across the western Kenai Peninsula, Anchorage Bowl, and Mat Valley but is expected to fill in by Monday afternoon. Models have struggled with this next system but have come into pretty good agreement on this latest model run. Precipitation type will be highly dependent on temperatures by tomorrow morning with snow or a rain/snow mix in the morning then changing over all rain as temperatures warm. Higher elevations (>2000 ft) will see snow with a possible changeover to a rain/mix for coastal areas. As temperatures drop back down towards freezing Monday night, should see precipitation change back.

The Susitna Valley over to the northern Copper River Basin will see higher snowfall totals ranging from about 2-4" for lower elevations to 4-8" for the areas along the Denali Highway and Paxon/Isabel Pass area through Tuesday afternoon. The Glenn Highway from about Sutton over to Tolsona could also see snowfall totals of between 2-4". These areas will be the most likely areas to see temperatures hovering near to below freezing allowing for snow to accumulate. Elsewhere, light accumulations will quickly melt as temperatures warm and snow changes over to rain. Thompson Pass will also see mostly snow, though there is a chance it could swing from snow to a mix of precipitation at times. However, it should remain cold enough for modest snowfall rates of 1" to 1.5" per hour with the potential to see accumulations above 10 inches from Monday through Tuesday. The coastal areas along the Gulf and Prince William Sound will see the bulk of precipitation from the system. The lower-elevations along the coast could see rainfall amounts of several inches. By late Tuesday, this system will start to push out of Southcentral, but showers could linger into Wednesday over the Copper Valley.

- PP

AVIATION

PANC...A few lingering light rain showers drifting near the terminal will dissipate by this evening. Some remaining patches of low stratus could occasionally still bring ceilings down into MVFR range this afternoon and evening. Otherwise, VFR conditions and light winds will persist through Sunday afternoon.