Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 653 PM EST Tue Jan 17 2023 Valid 12Z Sat Jan 21 2023 - 12Z Wed Jan 25 2023 ...Synoptic Overview and Sensible Weather... The medium-range forecast period will begin on Saturday as an occluded cyclone approaches from the south, bringing heavy rain to the immediate coast as heavy inland snow reaches peak intensity from the Kenai Peninsula to the southeast Panhandle. Near and just off the Gulf Coast, easterly wind gusts may reach 40-60 mph at times. Precipitation intensity should rapidly decrease later on Saturday as the cyclone rapidly weakens. Some residual moisture should make across the mountains and precipitate as light snow through the remainder of mainland Alaska from south to north for the rest of the weekend. The next occluded cyclone of concern will begin to edge closer toward the Aleutians on Sunday. This system will likely bring another potent surge of moisture toward the Gulf Coast as the triple-point approaches. Heavy rain near the immediate coast along with heavy mountain snow will once again impact the southern coastal sections into the northern Panhandle beginning Sunday night and into Monday. Potential exists for the heavy precipitation to extend westward to affect eastern portion of the Alaska Peninsula initially. There is also the potential for storm-force winds to develop near and just off the Gulf Coast Sunday night, as well as development of down-sloping winds from the Alaska range. Precipitation intensity is forecast to gradually trend downward thereafter. However, sustained onshore flow will keep the Gulf Coast region under a threat of heavy precipitation into early next week. In addition to the influx of moisture, 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 as described above across the Alaska domain through the medium-range period. The ECMWF and the EC mean support a cyclone track farther to the southeast off to the south of the Aleutians Sunday night versus a more northerly track by the CMC, while the GFS is in between these extremes. The WPC fronts/pressures forecast is primarily based on a 40% blend of the 12Z ECMWF/00Z EC mean, 40% 12Z GFS/GEFS, and 20% 12Z CMC/CMC mean, with increasing proportion toward ensemble means toward Day 8. This scheme yielded a solution very compatible to the previous WPC forecast package. Kong Hazards: - Heavy precipitation across portions of the Alaska Panhandle and southern mainland Alaska, Fri, Jan 20 and Sun-Mon, Jan 22-Jan 23. 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