Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 530 PM EST Tue Feb 22 2022 Valid 12Z Sat Feb 26 2022 - 12Z Wed Mar 2 2022 ...Overview... The upper ridge axis that will be in place across the state for the end of this week should be shunted east to western Canada by the weekend as a broad upper trough becomes established over the Gulf, with a couple of surface lows tracking towards the southeast Panhandle and British Columbia coast. A brief ridge axis builds northward over the Aleutians by early next week ahead of the next amplified trough approaching from the west. This will equate to above average temperatures across most of the mainland and periods of rain/snow for coastal areas. ...Guidance/Predictability Assessment... The 12Z deterministic guidance and the ensembles have the best overall depiction regarding the retreating ridge axis over eastern Alaska/western Canada at the beginning of the forecast period Saturday, and some latitudinal differences with the low pressure system over the Gulf region and also across the Bering. Basically all of the deterministic guidance and the 12Z GEFS/ECENS mean are now farther east with both of these lows compared to the 00Z ECENS. By Monday, models continue to struggle with the next low over the southern Gulf, with the UKMET northwest of the model consensus and the ECMWF stronger but close to the consensus regarding placement. However, the guidance at this time has a good handling of the ridge briefly building over the Aleutians. With the next storm system approaching the Aleutians by next Tuesday, it appears the GFS is stronger than the CMC/ECMWF, and a second strong storm likely follows that system by the middle of next week. Taking these factors into account, the WPC fronts/pressures forecast is primarily derived from a multi-deterministic blend for this weekend, and then greater weighting on the ECMWF and GEFS mean, along with some CMC, GFS, and previous WPC continuity going forward into early next week. ...Weather/Hazard Highlights... Strong low-level flow to the east of a wave (and trailing front) tracking from south of the Alaska Peninsula into the northern Bering Sea Friday into early Saturday will enhance the potential for heavy precipitation along the southern coast of the mainland late this week. The Kenai Peninsula should see the highest totals from this event. The heavy precipitation may extend as far east as the Panhandle, with low-confidence details for a possible trailing wave determining amounts and duration of activity over the southeastern coast/Panhandle over the weekend. Some precipitation could extend farther north over the mainland but in much lighter and scattered form. While precipitation along the southern coast and Panhandle should generally trend lighter with time, another area of moisture could reach the southeastern coast/Panhandle early next week if a northeastern Pacific system tracks close enough. A strengthening northwestern Pacific to western Aleutians/Bering Sea system and leading front may bring increasing winds and rounds of rain across the Aleutians for early next week. Coverage of much above normal temperatures will be greatest this upcoming weekend. Highest anomalies should be over the northwestern half of the mainland and some areas could see readings up to 35 degrees above normal, especially for lows. Above freezing temperatures will likely reach as far north as the Brooks Range. Temperatures should steadily moderate from south to north early next week but remain above normal over most areas for the majority of the forecast period. Hamrick Hazards: - Heavy precipitation across portions of southern coastal Alaska, Friday, Feb 25. - High winds across portions of southern mainland Alaska, Friday, Feb 25. 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