Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 531 PM EST Mon Nov 27 2023 Valid 12Z Fri Dec 01 2023 - 12Z Tue Dec 05 2023 ...Overview... Upper pattern for the first five days of December will feature a strong and fast Pacific jet off eastern Asia racing eastward toward southern British Columbia and the CONUS Pacific Northwest coast. In the mid-levels, troughing over the Bering Sea will slowly but steadily lumber eastward into the Gulf of Alaska by the start of next week, potentially supporting a more organized system. Otherwise, the pattern is relatively quiet with little to no precipitation in much of the interior and temperatures near to above normal. ...Guidance Evaluation and Preferences... With such a fast flow across the Pacific, model predictability is low by nature. Any apparent agreement may be transient and give a false sense of (higher) confidence. Nevertheless, the 12Z ECMWF/UKMET/Canadian did offer a reasonable well-clustered solution near the ensemble mean consensus (GEFS/GEPS/EPS) while the 12Z GFS was most different in timing (generally quicker) and track of some smaller-scale features. Thus, used a blend of mostly the non-GFS deterministic models with a minority weighting (~30%) of the ensemble means to start, with a transition toward about a 50/50 split mid-period and a majority ensemble weighting by next Mon/Tue (~70% ensembles) to account for increased uncertainty in any northeast Pacific system tracking into the Gulf or Panhandle. ...Weather/Hazards Highlights... For the Fri-Sat period, precipitation will focus mostly along the Aleutians, coastal Southcentral, and into the Panhandle as the west-east elongated/weakening system translates into British Columbia but onshore flow continues. By next Sun-Tue, a lead system around Sunday may track toward the Panhandle, which would bring an increased chance of more modest rain and snow to the region, but the majority of the precipitation looks to be focused just south of the area. Subsequent troughing and perhaps another system will likely keep the chances of precipitation high for the Panhandle next Mon/Tue, but details are murky. Highest totals may again be over the most southern areas of the Panhandle. Much of the interior will see only spotty light snow through the period. Temperatures are forecast to be near to above normal as the coldest of air will be over northeastern Russia under a cold upper low. Fracasso 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