Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 552 PM EST Mon Jan 29 2024 Valid 12Z Fri Feb 02 2024 - 12Z Tue Feb 06 2024 ...Bitterly cold temperatures across the Western Mainland will quickly rebound to near or above normal by early next week... ...Overview... Upper troughing over Alaska should shift east with time as a blocky upper ridge builds in upstream and shifts over the Mainland by the weekend. This should help moderate bitterly cold temperatures across the state as well as usher in a drier overall pattern for much of the Interior and the Southeast. A deep upper low will affect much of the Aleutians late this week with increased precipitation and gusty winds before rotating north/westward and becoming absorbed into an additional upper low dropping down from the Kamchatka Peninsula. Multiple streams of energy rotating around the base of this broad trough will keep conditions unsettled across the Aleutians and into the Alaska Peninsula and eventually the Southern Coast. ...Guidance Evaluation/Preferences... The latest 12z models and ensembles show pretty good agreement on the overall large scale pattern, but plenty of variability in the smaller scale flow details. Initially, there is increasing agreement that a deep surface low (central pressure possibly down near 960mb) will track across the west-central Aleutians Friday-Saturday, though the 12z CMC was a little faster/farther east and weaker with this by the weekend. After this, another couple of lows will pivot towards the Aleutians but there is increasing uncertainty in the placement and track of these systems. There is some consensus though that a system may move in towards the Alaska Peninsula/Bristol Bay region Monday-Tuesday but lots of uncertainty on the strength of this system and any potential weather impacts. The WPC blend for today leaned heavily on the 12z ECMWF and GFS given their better agreement with the ensemble mean guidance. Gradually increased the percentage of the ensemble means days 5-8 to attempt to break down some of the uncertainty near the Aleutians, but still keep some definition to systems that tend to get washed out by the ensemble means. Overall, this maintained fairly good continuity with yesterdays forecast. ...Weather/Hazards Highlights... Troughing in the Gulf to start the forecast period on Friday may continue to support moderate to locally heavy precipitation across the Panhandle region, but this should decrease in coverage by the weekend and beyond as upper ridging builds in to the region. A deep surface low near the Aleutians Friday-Saturday should support increasing precipitation from west to east as the cold front shifts through the Aleutians. Also likely to be a period of gusty winds given the strong pressure gradient present, but still some uncertainty on the strength of the overall system and whether winds will be particularly hazardous or not. Additional surface lows into early next week will continue to keep unsettled conditions across the Aleutians and farther east towards the Southern Coast with general moist southerly flow. One system lifting towards the Alaska Peninsula late period may begin to bring precipitation into parts of Southwest Alaska as well but lots of uncertainty on this still. Well below normal temperatures over the Mainland will linger through the end of the week but should eventually push eastward by the weekend. After this, a general warm up will be in place as upper ridging builds over the state, but parts of the eastern Interior may hold onto the below normal temps even into early next week. By next Monday-Tuesday, the greatest positive anomalies should be across western Alaska and the North Slope where daytime highs could be 10-20+ degrees above normal, a strong contrast to conditions currently. Southeast Alaska looks to stay near or below normal most of the forecast period. Santorelli 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