Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 658 PM EST Thu Feb 24 2022 Valid 12Z Mon Feb 28 2022 - 12Z Fri Mar 04 2022 ...Overview... A relatively mild pattern is forecast for Alaska during much of next week, as southerly flow dominates in between an upper low/trough across the Kamchatka Peninsula/western Aleutians/Bering Sea and ridging with an axis over northwestern Canada that should build over Mainland Alaska by mid next week. A couple of surface lows should move into the northeast Pacific/Gulf of Alaska while shortwaves rounding the western trough sends a couple of organized surface lows across the Aleutians and into the Bering Sea. Above average temperatures and periods of light to moderate coastal precipitation are expected with this pattern. ...Guidance/Predictability Assessment... Recent model and ensemble guidance continues to show good agreement on the large scale pattern described above, but struggle with the smaller scale details. There are some timing issues with surface and weak upper lows over the northern Pacific and Gulf of Alaska during the early part of next week, but a multi-model deterministic blend seemed to provide a relatively good starting point. Meanwhile, a main upper level low will meander near the Kamchatka Peninsula through much of next week as various shortwaves rotate across the western/central Aleutians and into the Bering Sea. The first should reach the Aleutians by around next Tuesday, weakening by Wednesday over the Bering Sea. The next system, with model guidance suggesting it should be stronger than the first, will dross the Aleutians on Thursday as it sends a frontal system towards the western Mainland and Alaskan Peninsula. This second system shows some degree of uncertainty in terms of track and placement of the surface low, but the ensemble means offer a good middle ground solution. The WPC forecast leaned more towards the ensemble means for this system given the late period timing. Some much smaller contributions from the deterministic solutions were included even through days 7 and 8 for a little bit of added system definition. This approach maintained good continuity with yesterdays WPC forecast as well. ...Weather/Hazard Highlights... Moist southerly flow is forecast to keep rain and snow chances in the forecast particularly across coastal areas. Precipitation could be enhanced into early next week with the possibility for a lingering low pressure system, but with only light to perhaps locally moderate amounts expected. Precipitation over the southern Coast and Panhandle should trend lighter with time as upper level ridging moves into the region. Increasing precipitation and possibly gusty winds are then forecast for the Aleutians through much of the workweek, with amounts and timing dependent on low pressure/frontal systems. Current forecasts show the best signal for notable precipitation there by around next Wednesday-Thursday. Above average temperatures will abound over Alaska through much of next week, especially for lows. The highest anomalies are forecast over the northern and western parts of the mainland for the beginning of the week, with lows up to 30-40 degrees above normal and highs 20-30 degrees above normal. Anomalies will ease with time, reaching near to slightly below average for highs in the Panhandle in the southeastern mainland by midweek, but remaining above normal farther north and west for the week. Santorelli No significant hazards are expected over Alaska during this forecast period. 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