Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 542 PM EST Sun Nov 17 2024 Valid 12Z Thu Nov 21 2024 - 12Z Mon Nov 25 2024 ...Windy/snowy pattern for Northern Alaska and enhanced gap winds for a cooled Southeast Alaska... ...Guidance Evaluation/Preferences... Guidance seems better clustered now valid for Thursday into Saturday in amplified flow, bolstering forecast confidence in a composite GFS/ECMWF/UKMET/Canadian model blend. Yesterdayā€s 12 UTC GFS seemed to crash energy too robustly into the ridge next weekend, but todayā€s 12 UTC GFS backed off from that outlier solution. This is more in line with a preferred composite of compatible GEFS/ECMWF/Canadian ensemble means later next weekend into early next week amid growing forecast spread in guidance. Todayā€s 12 UTC ECMWF may be the outlier now versus the ensemble means at these longer time frames. ...Weather/Hazards Highlights... Main impacts will focus with system energies riding the periphery of an Aleutians to Interior upper ridge. Expect midweek enhanced winds and snow over the North Slope/Brooks Range underneath an exiting Arctic Ocean closed low. This now seems more likely to be followed by another impactful Bering Sea to West/Northwest Alaska to North Slope/Brooks Range and northern Interior Alaska wind/snow storm threat into next weekend to monitor for intensity and local detail/threats. Deep layered maritime lows dug to the lee of the main upper ridge should hold south of the state, mainly as a maritime threat, but with a enhanced gap winds threat to the northeast of the main circulation with cold air intrusion and settlement across Southeast Alaska and vicinity. Amplified upper ridging from the Aleutians to the Interior and storm track from the Bering offers a moderated temperature pattern into next weekend until northern periphery of the ridge flattens and frontal cooling returns over the mainland with passage of the next main system in an ongoing series. Schichtel 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