Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 552 PM EST Mon Feb 10 2020 Valid 12Z Fri Feb 14 2020 - 12Z Tue Feb 18 2020 ...Guidance and Uncertainty Assessment... The 12 UTC ECMWF is the deterministic model that offers a solution Friday/Saturday that seems best aligned today with the ensemble means and WPC continuity. This solution still seems reasonable. Accordingly and after collaboration with local WFO offices, it was also agreed that the forecast starting point for the WPC Alaskan product suite would then be mainly derived from the compatable 12 UTC NAEFS mean and especially the 12 UTC ECMWF ensemble mean Sunday-next Tuesday. Guidance from the 19 UTC National Blend of Models was also included in these composite blends. The overall pattern evolution seems less predictable than normal, so only modest forecaster adjustments were applied to add increased detail consistent with individual weather feature predictability. ...Weather Pattern and Hazards Highlights... Frigid air deeply settling over the Interior and North Slope may prove slow to moderate over the next week as Arctic stream upper troughing digs back over the region. Meanwhile, a powerhouse storm will focus a threat of heavy precipitation/winds/seas across the Aleutians/Bering Sea by Thursday. The deep low will gradually weaken Friday/Saturday as a developing triple point low is expected to progress eastward across the northern Gulf of Alaska and offer a moderate precipitation threat into the southern and southern Alaskan tier. There is an increasing guidance signal that additional systems feeding into the Gulf in this stream will offer some potential to phase with Arctic stream energies more ernestly in about a week. Stream phasing is not very predictable at long lead times, but could support deep northern Gulf low development along with unsettled seas and a heavy precipitation threat into southern and southeast Alaska. Schichtel 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 Hazards: - Heavy precipitation for parts of the Alaska Panhandle and mainland AK, Mon, Feb 17. - Much below normal temperatures for parts of mainland Alaska, Thu-Sun, Feb 13-Feb 16. 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