Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 630 PM EST Sat Jan 01 2022 Valid 12Z Wed Jan 05 2022 - 12Z Sun Jan 09 2022 ...Record cold possible for some areas of the Panhandle next week... ...Overview... A blocky pattern will continue through much of the medium range period over the high latitudes as an upper high over northeastern Russia/Chukchi Sea meanders in place while reorienting itself. This favors very cold high pressure over most of the region south of the Brooks Range, while a storm track near the Aleutians leads to periods of generally light to moderate precipitation and brisk winds there, before the possibility of increasing moisture for Southcentral Alaska by next weekend. ...Guidance Evaluation and Preferences... Model guidance particularly in terms of the ensemble means showed reasonably good agreement with the overall blocky pattern, though with some typical model differences in the details. The upper high centered over northeastern Russia and the Chukchi Sea still looks to be oriented west-east on Wednesday before gradually changing shape and reorienting north-south by Friday, and back to west-east over the weekend. Its position and orientation were pretty consistent among model guidance, except for the 12Z UKMET, which tended to have a westward displacement of the upper high compared to consensus around days 4-5. Though with some differences in timing and strength, shortwave energy could drop south through northwestern Canada on the eastern side of the high and push a cold front through eastern parts of Alaska late in the week. For the early part of the period, favored a deterministic blend of the 12Z GFS/ECMWF/CMC, which aligned well with the ensemble means. By Friday to Sunday (days 6-8), deterministic model variations and thus uncertainty increase for the prevailing storm track near the Aleutians and potentially eventually spreading into the Gulf of Alaska next weekend as the influence of the upper high retracts. Once again GFS runs retrograde a surface low north of the Aleutians by Saturday led by different placement of a closed mid-upper low compared to the EC/ensemble guidance, which is not impossible but currently contradicts the ensemble guidance. Favored the ECMWF in terms of the deterministic models instead, and gradually increased the weighting of the ensemble means gradually to 50% by the end of the period, but kept a good proportion of the EC in the blend to enhance strength of features. ...Weather/Hazard Highlights... Precipitation during the latter half of next week will be generally limited to light to locally moderate rain/snow over the Aleutians to Kodiak Island, while much of the mainland should see dry conditions given periods of high pressure. One exception over the mainland could be light snow showers for far northeastern Alaska as a weak surface cold front slips through northwest Canada. Then by next weekend, a warm front is currently forecast to push toward or into the Gulf stemming from a low over the northern Pacific, increasing moisture and potentially spreading rain/snow into Southcentral Alaska. Given the cold surface high pressure encroaching into Alaska, much below normal temperatures remain forecast for the mainland south of the Brooks Range, gradually trending less extreme with time. However, temperatures over the Panhandle should stay well below normal the entire week with offshore flow, and temperatures could approach record cold for overnight lows and/or daytime highs. The North Slope will see well above average temperatures midweek moderating closer to normal by next weekend. Tate 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