Alaska Extended Forecast Discussion...UPDATED National Weather Service College Park MD 643 PM EDT Sat Jul 5 2025 Valid 12Z Wed 09 Jul 2025 - 12Z Sun 13 Jul 2025 ...Synoptic Overview... A strong Arctic trough and surface front will sink south across the northern half of Alaska next week, bringing well below average temperatures to the North Slope and portions of the Interior and chances for snow showers to the Brooks Range. Meanwhile, a series of surface low pressure systems will track across the Pacific into the Gulf, which will result in unsettled weather through the period for the southern half of the state and heavy rain potential for Southeast Alaska. ...Guidance Evaluation and Preferences... There is fairly good agreement on the upper level pattern through the period, with an average amount of spread for this time period. Model differences late in the period (next weekend) will have the largest influence on the weather forecast. Models are all depicting an upper low developing over the Bering Sea that will slowly sink southeast across the Aleutians and eventually into the Gulf. The evolution of this feature will greatly influence timing and position of surface low pressure systems moving into the Gulf towards Southeast Alaska. The 12Z CMC/ECMWF are well clustered, bringing a portion of the low's energy south across the Aleutians late Saturday into Sunday, but the 12Z GFS keeps the low over the Bering through the period. The ensemble means from the CMCE/ECENS/GEFS are all in good agreement on moving the upper low south towards the Aleutians on Sunday. For this reason, the WPC forecast for next weekend leans more towards the ECMWF/CMC and ensemble means than the GFS. The WPC forecast blend consisted of a near even blend of the 12Z GFS/ECMWF/CMC/UKMET for the first two days of the period (Wednesday-Thursday), which resulted in a middle of the road solution that seems to represent the pattern well. Ensemble means from the CMCE/ECENS/GEFS were added in increasing amounts while the GFS was phased out of the blend for Friday through Sunday. ...Weather/Hazards Highlights... A strong Arctic front will bring well below average temperatures to the northern half of Alaska next week. Temperatures are forecast to drop 10-20 degrees below normal across the North Slope and 5-15 degrees below normal for much of the Interior. For the North Slope, high temperatures are forecast to only reach the 40s and lows will likely be near to just below freezing. For the Interior, highs are forecast to be in the 50s and lower 60s and lows are expected to be in the 40s. Temperatures will be cold enough in the Brooks Range to support chances for snow showers as the Arctic front moves through Tuesday into Wednesday. Though less extreme, below normal temperatures are also expected for the South-Central Mainland and Southeast Alaska where increased cloud cover and precipitation chances are expected through the period as low pressure systems move into the Gulf. Given the west to east low tracks and persistent onshore flow, Southeast Alaska is likely where the majority of the rain will fall next week. Mid-next week, heavy precipitation is expected to focus on the Kodiak Island and Kenai peninsula areas, then the focus will shift to Southeast Alaska Friday though the weekend. Dolan 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