Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 733 PM EDT Sat Mar 22 2025 Valid 12Z Wed 26 Mar 2025 - 12Z Sun 30 Mar 2025 ...General Overview... A broad upper low/trough is expected to encompass most of the Gulf region for the second half of the week, with a forming low over the eastern Gulf that will likely lift north and then northwest into Friday and Saturday over the northern Gulf as a blocky upper level pattern becomes established. Meanwhile, a strong upper ridge becomes established over the central/western Aleutians and over the southern Bering Sea going into the end of the week and next weekend, with some shortwave energy crossing the Bering Sea north of the ridge axis. ...Guidance/Predictability Assessment... Similar to yesterday, the ensemble means are overall in agreement on the large scale synoptic pattern across the domain in how the broad upper low gyre evolves across the Gulf and the downstream upper ridge across the Aleutians and Bering Sea. However, the deterministic guidance continues to struggle on how shortwaves from eastern Siberia cross the northern periphery of the Aleutians ridge and potentially affect southwestern Alaska. The CMC has trended closer to the model consensus compared to yesterday in having less potent shortwave energy crossing the Bering. The GFS remains stronger with a closed upper low crossing the Bering and reaching the western mainland around Friday, but its ensemble mean is not on board with this scenario. Given the deterministic spread by next weekend, the ensemble means accounted for about 50-60% of the model blend by that time. ...Weather/Hazards Highlights... The southern coast and Panhandle will likely see periods of mainly light to moderate coastal rain and mountain snow mid-week in association with low pressure settling over the central/southern Gulf. Much of mainland Alaska north of the coastal mountain ranges should be dry for most of the forecast period, but surface low re-development over the northern Gulf may result in additional rain and mountain snow for Southeast Alaska. Nothing appears to reach hazardous level criteria through the entire forecast period. Expect temperatures to gradually moderate closer to normal by mid-week as the upper trough gradually weakens across the western mainland. The North Slope and Brooks Range should be near or slightly below average through much of next week, while the Interior and the Panhandle could see a mix of above and below normal temperatures. 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