Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 557 PM EST Sat Jan 30 2021 Valid 12Z Wed Feb 03 2021 - 12Z Sun Feb 07 2021 ...Overview and Guidance/Uncertainty Assessment... Positive height anomaly centers will meander over the Arctic north of Siberia and south of the Gulf of Alaska, leaving an opening in between for the northern branch of split flow across the Bering to push eastward along 50-55N. The longwave setup lends itself to a bit of uncertainty in embedded smaller-scale features that, with today's deterministic model runs, escalated rather sharply after about next Thursday. In addition, the 12Z ECMWF was different in its handling of a Wednesday upper low supposedly forecast to dip southward south of the Aleutians though it showed a rather robust northern portion of that otherwise more southern (south of 45N) upper low. In order to prevent large changes to the forecast, opted to rely mostly on a blend of the ensemble means (GEFS and ECMWF ensembles) as upstream surface low development into the Bering was quite chaotic and without a clear trend. This would allow ridging to build back across the Interior Thursday but allow weaker shortwaves to still push inland, in between the deeper upper ridge centers to the NW and SE. QPF differences also remained for areas north of the Alaska Range -- wetter GFS earlier, and wetter ECMWF later. ...Weather/Hazards Highlights... Precipitation across the northern Gulf/southern mainland next week will generally be on the light to perhaps modest side, enhanced by weaker areas of low pressure into the Panhandle. Generally do not prefer any solution that shows a stronger low/precip area (GFS) into the Gulf at this point. By next Thu-Fri, system into the eastern Bering will spread snow across the Interior as its old triple point weakens but carries moisture eastward. Another system late Fri will spread its moisture eastward as well, but perhaps over southwestern areas (Y-K Delta). Temperatures will trend milder than normal through the period, limiting the below normal temperatures to the Panhandle and far northeastern areas Wed-Fri. Fracasso Additional 3-7 Day Hazard information can be found on the WPC medium range hazards 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