Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 604 PM EST Mon Jan 16 2023 Valid 12Z Fri Jan 20 2023 - 12Z Tue Jan 24 2023 ...Synoptic Overview and Sensible Weather... A broad upper trough is forecast to be in place across much of the Bering Sea and the Aleutians for Friday and into the weekend, with a closed polar low situated over far eastern Siberia that will slowly track westward. An active weather pattern will continue across the North Pacific with two well defined storm systems affecting Alaska. The first storm system is forecast to produce moderate to heavy coastal rain and heavy inland snow, mainly from the Kenai Peninsula to the southeast Panhandle, along with gusty onshore winds that may reach 40-60 mph at times. Several inches of liquid equivalent precipitation is likely across the coastal terrain, especially from the eastern Kenai Peninsula to the St. Elias Mountains through early Saturday. Enhanced runoff is expected for the lower coastal elevations. Some light snow will likely affect portions of the southern Interior region. Looking ahead to Sunday, a second well organized surface low will likely approach the eastern Aleutians and the western Gulf, with another surge of strong onshore flow across the Alaska Peninsula to the Yukon border. There is the potential for storm force winds across the coastal and offshore waters if the low remains strong as it approaches land. There may also be some down sloping winds from the Alaska range. The onshore flow will likely keep temperatures relatively mild by January standards across southern Alaska, especially near the coast. The coldest weather is expected to be north of the Brooks Range where subzero high temperatures are likely most days. ...Model Guidance Assessment... The 12Z model guidance suite has a very good overall depiction of the synoptic scale pattern pattern for the end of the week across the Alaska domain, and there is better model support for a triple point low developing on the front as it approaches the northern portion of the southeast Panhandle Friday night. There is some improvement in the overall model spread going into the Sunday-Monday time period regarding the next organized storm system approaching the eastern Aleutians and the Alaska Peninsula. The ECMWF has trended stronger compared to its 12Z run yesterday, and is generally southeast of the CMC and GFS solutions. The storm should weaken steadily by Monday night and into Tuesday as it moves inland across the mainland. The WPC fronts/pressures forecast is primarily based on a multi-deterministic blend with some ensemble means through Saturday, and then gradually increasing use of the ensemble means for early next week whilst still maintaining some previous WPC continuity. 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