Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 737 PM EDT Wed Mar 19 2025 Valid 12Z Sun 23 Mar 2025 - 12Z Thu 27 Mar 2025 ...Overview... A slow moving surface low is forecast to be in place across the northern Gulf for Sunday into the beginning of next week. Onshore flow ahead of this low will keep coastal showers and mountain snow ongoing during this time. A second low develops farther south later in the forecast period, but should not be impactful to most land areas. Meanwhile, a cold upper low/trough will tend to keep cold weather in place across western portions of the mainland, while upper level ridging across the eastern mainland will result in generally above average temperatures for late March. ...Model guidance and predictability assessment... The 12Z model guidance suite features good overall agreement across the Alaska domain Sunday and into Monday, with mainly mesoscale differences noted with the low pressure system situated over the Gulf region. Going forward into the middle of the week, model and ensemble spread increases significantly with timing and amplitude with shortwave energy crossing the Aleutians and North Pacific, while things are in better agreement over the mainland. The ensemble means serve as a better starting point in the forecast process for the Wednesday to Thursday time period owing to the deterministic model differences. ...Sensible weather and potential hazards... The southern coast and Panhandle will likely see periods of mainly light to moderate coastal rain and mountain snow from the weekend into Monday in association with gradually weakening low pressure settling over the northeastern Pacific/southern Gulf of Alaska. Flow behind the Pacific low pressure systems may produce periods of brisk to strong northerly winds over the Aleutians and into the Alaska Peninsula, most likely during Sunday-Monday while remaining below hazardous thresholds. Portions of the western mainland may see scattered light snow continuing into the weekend along a persistent wavy surface front that should begin to push eastward around Sunday. Flow around high latitude Arctic high pressure should maintain brisk easterly winds across the North Slope through the weekend and possibly into early next week. The upper trough extending southeast from an eastern Siberia upper low this weekend will likely keep temperatures below normal over western portions of the mainland. The below normal anomalies should gradually expand eastward into early next week as the upper trough axis moves eastward. Since the upper trough will be weakening with time, temperatures should moderate closer to normal by Tuesday-Wednesday. Most other parts of the mainland will likely see above normal readings most of the time. Hamrick 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