Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 525 PM EST Sat Nov 26 2022 Valid 12Z Wed Nov 30 2022 - 12Z Sun Dec 04 2022 ...Heavy snow/ice and freezing rain threats for Southwest/Western Alaska into the Interior mid-later next week... ...Guidance/Predictability Assessment and Preferences... The 12 UTC GFS/ECMWF/Canadian model solutions are well clustered Wednesday-Friday in a pattern with seemingly above average predictability and in line with 12 UTC GEFS/ECMWF ensembles. Prefer a composite of these guidance pieces to mitigate smaller scale system variance. The 12 UTC UKMET in particular seems an outlier with these embedded system timings, but at minimum shows lingering weather focus uncertainty. Forecast variance with embedded systems grows more quickly by next weekend, but prefer to still blend the GFS/ECMWF/Canadian models with the GEFS/ECMWF ensemble means to provide as much common system depiction amid growing uncertainty. This forecast strategy has been collaborated with local Alaskan forecast offices. Forecast product continuity is less than stellar heading into next weekend given embedded system focus variance growth at these longer time frames. ...Weather/Hazards Highlights... Models and ensembles agree to sustain an amplified mean upper ridge position up over western Alaska. The ridge will support unseasonably warm conditions over much of the mainland outside of the southeastern Interior and the Southeast Panhandle, with greatest warm anomalies expected from western Alaska through the North Slope next week. This solution is well supported in models and ensembles, bolstering forecast confidence. In this pattern, a leading/organized low will lift into the Arctic Ocean by midweek and the progression of the supporting upper trough across the Bering Sea will act to focus midweek moisture into western Alaska through the top of the upper ridge. Another deepened cyclone is then slated to track into the Bering Sea toward Alaska later next week into next weekend and act to rebuild western Alaskan ridge amplitude. While there is uncertainty with the interactions of Bering Sea systems moving around or more bodily into the ridge next week, the aforementioned preferred guidance composite would highlight repeatable threats for heavy snow/ice and freezing rain across Southwest/Western Alaska into the Interior midweek and likely again later next week/weekend in a pattern periodically channeling system energies and above average moisture into the region. Downstream of the upper ridge, a deepened low and digging upper trough will work away from the Panhandle midweek. However, cold high pressure in the wake of the system will linger over southeastern Interior Alaska valleys and settle southward across the Panhandle next week. Strong northerly gap winds may linger into Wednesday behind the system over the Panhandle due to the strong and cold high pressure system. The strong winds will also accompany temperatures around 20+ degrees below average over the Panhandle. Additional system energies digging to the lee of the mean upper ridge position should act to maintain unsettled, but still cold conditions over the region through the period. Schichtel 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