Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 515 PM EST Sat Jan 22 2022 Valid 12Z Wed Jan 26 2022 - 12Z Sun Jan 30 2022 ...Overview... A cold upper trough will move in from the Bering and replace the upper ridge that will be over the state through Monday, and results in much colder weather spreading from west to east through the middle to end of the week. Meanwhile, a storm system over the Gulf will lift northeastward towards the southeast Panhandle region and result in unsettled weather near the coast for the end of the week, and a couple of big storm systems crossing the western Aleutians will also tend to keep rain/snow across the islands through the middle to end of the week. ...Guidance/Uncertainty Assessment... The 12Z model guidance suite is in good synoptic scale agreement across most of the domain for the middle of the week, with the greatest model spread evident over the Gulf region where the 12Z CMC is displaced with a surface low that is not supported by the other guidance. By Thursday, the GFS is displaced to the west of the model consensus and to a lesser degree the GEFS mean with the longitudinal axis of the upper level ridge building over the Bering, and this affects the low placement over the Gulf as the omega block pattern tries to develop. By next weekend, the GFS appears to be in better alignment with the ensemble means with the ridge, although still northwest of the consensus with the Gulf low. Therefore a multi-model blend (greater weighting to the UKMET and ECMWF) through Thursday night seems to be a prudent starting point in the forecast process. By the end of the forecast period next weekend, more of the GFS is used in place of the UKMET whilst increasing use of the ensemble means. ...Weather/Hazard Highlights... The pattern change that is forecast to take place across much of the state will tend to result in less snow showers across the mainland as arctic high pressure builds into the region. The exceptions will be across the southern coastal region and the southeast panhandle where moist onshore flow ahead of the Gulf low will likely produce widespread precipitation starting on Wednesday, with very heavy snow for the coastal mountain ranges and strong winds near the coast. Periods of rain/snow are also likely through the middle to end of the week for the central and western Aleutians. The passage of the strong cold front early in the week will cause temperatures to be near to below normal levels through mid-week across most of the state as the ridge moves away from the state and the arctic trough builds back in. 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