textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

The broad upper trough that brought the widespread snowfall and cold temperatures will continue to shear apart today and gradually retreat north and west over the coming days. Our focus is now on a broad north Pacific trough with multiple embedded shortwaves that will lift north into the Gulf this evening and into the remainder of Southcentral over the weekend. The evolution of this system is very complex and remains poorly resolved in model guidance. The main complexity is how the incoming warm front, inverted surface trough and elongated surface low will interact with the deep Arctic airmass that will get pushed over Southwest Alaska. The Blizzard Warning remains in effect for Kodiak Island but there is still high levels of uncertainty for snow amounts, with some recent model guidance now showing the front well to the east of the island. This is an outlier, but a low probability possibility nonetheless.

The general timeline of events for this system will be strong winds and snow for Kodiak starting this evening and continuing as late as Saturday morning. Rain may mix in at times. This will depend on the east-west position of the surface low as it develops and moves north of the Island. By Friday afternoon, widespread snow is expected for the Prince William Sound communities, which will likely spread inland to most of, if not all of Southcentral overnight. This is where the forecast becomes most uncertain, as this is where there are significant differences in the positioning of the Arctic trough over Southwest Alaska. A north-south oriented band of moderate to heavy snow is expected to develop on the eastern periphery of the trough, anywhere from the western Susitna Valley, to right over the Cook Inlet areas that were most recently impacted by heavy snow. Some solutions have this over the Copper Basin, but this is a far eastern outlier. Wherever this band sets up is likely to get 6-12+ inches of snow.

Forecast confidence is highest for the eastern Sound and southern Copper Basin, where somewhat regardless of the upper level feature to the west, will receive the bulk of the precipitation from the warm front. A Blizzard Warning is now in effect for Thompson Pass, a Winter Storm Warning is in effect for Ernestine and 46 mile, and Winter Weather Advisories are in effect for McCarthy, Chitina, and Kenny Lake. Stay tuned to the forecast for more updates as this system progresses north.

-CJ

AVIATION

PANC...Satellite imagery this morning reveals a 200 to 500 foot low stratus deck in and around the terminal. For this morning, ceilings and visibility will bounce around between VFR to LIFR at times due to low stratus and mist/fog meandering around the terminal. This should clear out fully later this morning as dewpoint depressions widen. VFR conditions will persist after this morning. Light northerly winds will persist through today. Northerly winds pick up to 10 kts or a little greater by tonight and Saturday morning. These elevated northerly winds could cause some instances of drifting snow tonight and Saturday morning.