Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 744 PM EDT Sun Oct 13 2024 Valid 12Z Thu Oct 17 2024 - 12Z Mon Oct 21 2024 ...Overview and Guidance Evaluation/Preferences... The weather pattern across the Alaska domain will be featured with a surface high situated over the Bering Sea and extending inland across the mainland for the end of the week. A pair of surface lows over the Gulf will likely consolidate into one main low, but most of the bad weather should remain south of the mainland, although the southeast panhandle could be affected going into the weekend. A trend to colder weather is likely for most of the state through the extended forecast period. Towards Sunday and Monday, attention then turns to the western Bering as the next storm system begins approaching the region. The 12Z model guidance is in relatively good overall agreement across the Alaska domain for Thursday, although there are already some differences in the structure of the low(s) passing south of the Aleutians and then into the Gulf. These differences involve whether there is just one main low, or two separate lows pivoting around each other. Forecast confidence is good over the mainland and the ridge holding over the Bering through Friday. Looking ahead to Sunday and beyond, models are showing a stronger signal for a storm over eastern Siberia with a cold front approaching the western Bering, although there remains a good deal of spread in the ensembles and there will likely be adjustments for timing and/or intensity in future forecasts. The ensemble means were gradually increased to about 50% by next Sunday/Monday. ...Weather/Hazards Highlights... A quieter weather pattern is expected across most of the mainland for the end of the week. There will likely be some showers and mountain snow for the southeast panhandle region for Friday into Saturday as the surface low from the Gulf approaches the region. Farther to the north across the Brooks Range and up to the Arctic Coast, periods of snow are likely as an arctic shortwave and surface trough passes through the region, with several inches of accumulation likely by Friday afternoon across northeastern Alaska. Elsewhere across the mainland, mainly dry conditions can be expected. Temperatures will be rather chilly across most of the state in the wake of a strong cold front, with more of an arctic air mass place. Daytime highs will likely be near or below freezing for most inland areas by the end of the week into Saturday, and mid 30s to mid 40s near the southern coast. Some valley locations near the Brooks Range could have overnight lows near zero or even colder by Thursday and Friday. Warm air advection ahead of the next Bering Sea storm system could result in milder conditions returning to southwestern Alaska by next Monday. 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