Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 654 PM EST Sat Jan 14 2023 Valid 12Z Wed Jan 18 2023 - 12Z Sun Jan 22 2023 ...Synoptic Overview and Sensible Weather... A fairly progressive flow pattern is expected to be in place across the northern Pacific mid-late next week, with a broad upper trough over the Bering Sea and western Alaska, and upper level ridging then builds across western Canada by Friday and next weekend as a +PNA pattern attempts to develop. At the surface, a well organized low is expected to track northeastward just to the southeast of the Aleutians and likely reaching the vicinity of Kodiak Island by Friday morning. This storm system will likely 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 40-50 mph at times. Most of the Interior should remain dry with perhaps some light snow in a few locations. The onshore flow will likely keep temperatures slightly above average across southern Alaska, and near to below average for the Interior and the North Slope. ...Model Guidance Assessment... The 12Z model guidance suite has a very good overall depiction of the synoptic scale pattern pattern on Wednesday, and better day 4 agreement compared to yesterday. For the storm system approaching the southern Alaska coast late next week, the models are generally well clustered through Thursday night, and the GFS appears to develop a triple point low near the coast by Friday morning. Looking ahead to next weekend, models differ more significantly with shortwave energy and surface lows originating from the far western Aleutians, but there is a decent signal among the deterministic GFS/ECMWF/CMC for a potentially well organized and strong low pressure system to enter the Gulf by next Sunday, with the GFS fastest and the CMC/ECMWF well to the south, so that will be something to monitor going forward. The WPC fronts/pressures forecast is primarily based on a GFS/ECMWF/CMC blend with some ensemble means through Thursday, and then gradually increasing use of the ensemble means for the Thursday through Saturday time period 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