Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 501 PM EST Sat Nov 28 2020 Valid 12Z Wed Dec 02 2020 - 12Z Sun Dec 06 2020 ...Storm systems are expected to lie over and south of Alaska during the next week... A strong blocking ridge across Saskatchewan will force the flow across eastern and central Alaska to be southerly through the period, with low pressure areas impacting the state late Tuesday (where guidance is agreeable) and perhaps Thursday/Friday. A significant storm is expected to move well to the southwest of the state late next week into the weekend. This trio of cyclones is expected to keep seas across the northeast Pacific quite unsettled through the period with wet and windy conditions predominately for south-central and southeast sections of the state. The pressures, 500 hPa heights, and wind grids were deterministic based (12z Canadian, 12z UKMET, 12z GFS, and 12z ECMWF) from late Tuesday through Wednesday before increasing weights of the 12z NAEFS mean and 00z ECMWF ensemble mean were used thereafter. The remainder of the grids made greater use of the ensemble means. In the pressure pattern, this kept rather good continuity. Much of the North Slope as well as the eastern two-thirds of the mainland should see above to well above normal temperatures through the period within the southerly flow regime with highest anomalies likely to be for lows (20F or more above normal in some cases). The Panhandle will tend to be above normal as well, with the potential for a foot of liquid equivalent precipitation within a persistent onshore flow regime. Expect the best potential for below normal temperatures over the west/southwest part of the mainland and through the Peninsula/Aleutians, in an area of persistent mid-level troughing into mid-week. It is uncertain whether or not western AK will be in an area of ridging or troughing late week into next weekend, though there was a slight lean in the ensemble mean for at least some troughing, which if verified would favor somewhat below average temperatures. Roth 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