Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 654 PM EST Thu Nov 11 2021 Valid 12Z Mon Nov 15 2021 - 12Z Fri Nov 19 2021 ...Overview and Guidance Evaluation/Preferences... Negatively tilted troughing across the Bering Sea/central-eastern Aleutians to start the period on Monday will gradually weaken and shift eastward sending a surface low pressure system into the Gulf of Alaska by mid-week. This low should linger, in a weakened state, through the remainder of the week as it interacts with more amplified troughing digging south across the Mainland. Meanwhile, upper ridging should slide eastward across the Aleutians ahead of the next upper low which moves towards the region later next week. For days 4-5/Monday-Tuesday, the guidance shows reasonable agreement on this set-up to warrant a general deterministic model blend. After this, the models begin to diverge with the typical timing and detail differences regarding shortwave energy into the Gulf and also energy/surface low south of the Aleutians next Thursday-Friday. The biggest model concern is that the 12z ECMWF drops a deep upper low north of Alaska into the Mainland by next Wednesday. The GFS/CMC and the ensemble means support more amplified troughing across the state while the core of the upper low stays north of the state in the Arctic. As such, the WPC forecast leaned away from the 12z ECMWF days 6-8 with more emphasis towards the ensemble means. ...Weather/Hazard Highlights... Generally dry conditions are likely for most of the mainland through next week, other than a few possible snow showers. A surface low exiting the Gulf on Monday may continue to bring some light to moderate precipitation to the Panhandle region, though the best precipitation chances should stay to the south. Precipitation should accompany the next cold front, spreading eastward from the Aleutians to the Peninsula region on Monday into Tuesday. After a brief dry period, precipitation should once again increase across the Panhandle by mid week as the surface low makes its way into the Gulf and a stationary frontal boundary sets up along the coast. The next system into the western Bering/Aleutians should bring another round of unsettled conditions to the region with light to moderate precipitation and gusty winds for the western Aleutians and Bering Sea. Below normal temperatures should prevail across much of Alaska (with the exception of the North Slope region) through next week as surface high pressure becomes established across much of the state. The most pronounced anomalies should be over the western and southwestern part of the state where daytime highs could be as much as 15-30 degrees below normal. The north slope should begin above normal, but quickly moderate back closer to normal the rest of the week. Santorelli 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 No significant hazards are expected over Alaska during this forecast period. 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