Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 654 PM EST Sun Jan 29 2023 Valid 12Z Thu Feb 02 2023 - 12Z Mon Feb 06 2023 ...Pattern overview and Weather/Hazard Highlights with Model Guidance/Predictability Assessment... With the anomalous upper ridge breaking down over Alaska, a more typical west to east storm track is forecast to resume across the North Pacific to the Aleutians during the medium-range period, as a piece of the anomalous ridge retreats into the Arctic Ocean and evolves into a closed High. Model guidance shows very good agreement that mainland Alaska will be situated in between these two synoptic scale regimes. While the main center of a polar vortex meanders over eastern Siberia, low pressure systems that form along the North Pacific storm track through the latter half of next week appear to be on the weak side and do not appear to consolidate into a larger system as they move pass the Aleutians and then south of the Gulf of Alaska. In this pattern, lingering low pressure centered over the Gulf of Alaska midweek will bring unsettled weather slowly eastward from the southern coastline to the Panhandle through the end of this week. Precipitation is not expected to be excessive, though the southern Panhandle should see moderate to heavy amounts of mountain snow Thursday/Friday. Meanwhile, model ensembles show decent agreement that moisture ahead of a larger cyclone will gradually advance across the Aleutians from west to east during the weekend. This system does not appear to be excessively strong while moving across the Aleutians. A period of moderately heavy precipitation is possible Sunday to Monday along the windward side of the Alaska Peninsula to the Kenai Peninsula as a low pressure wave may form along the occluded front just off the coast. Temperature-wise, a slow cooling and drying trend is forecast to continue across the entire mainland Alaska into the medium-range period, bringing temperatures down to near normal by the end of the week when sub-zero readings are forecast to expand across the northern half of the state. But as the larger cyclone moves across the Aleutians and into the Bering Sea, deeper and stronger southerly flow ahead of the system will help set off a warming trend across much of Alaska by Sunday into Monday. The WPC Alaskan medium range product suite was derived from a 40% blend of the 06Z & 12Z GFS/12Z GEFS, 40% from the 12Z ECMWF/00Z EC mean, and 20% from the 12Z CMC/CMC mean, with increasing usage of the ensemble means for Days 6-8 in a pattern with overall near to above average predictability. The results appear quite compatible with yesterday's forecast package. Kong Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html