Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 326 PM EDT Thu Apr 18 2019 Valid 12Z Mon Apr 22 2019 - 12Z Fri Apr 26 2019 ...Guidance/Predictability Assessment and Weather Highlights/Hazards... Model variance grows quickly next week, but mainly with small-mid scale offshore lows. GEFS/ECMWF ensembles seem reasonably compatable early-mid next week, but even the means become quite varied by later next week with potential renewed Pacific storm developments to the south of the Aleutians. The WPC Alaskan medium range product suite was mainly derived from a model/ensemble composite blend Monday, then ensemble means thereafter amid growing forecast spread. However, there is decent confidence the pattern next week will be highlighted by a deepened and meandering storm/low set to spin heavy winds/high seas and heavy precipitation over the northern Gulf of Alaska and southern Alaska, especially in favored terrain early week. There will also be an additional coastal focus into southeastern Alaska with development of a persistent and moist onshore fetch. This will overall be supported by amplified mean closed low/troughing aloft over the Gulf, with periodic upstream reinforcement from upper trough energies digging down over unsettled western/southwest Alaska and the Bering Sea. There is also some signal for renewed storm potential over the northern Pacific along/south of the Aleutians by mid-later next week. Given much greater uncertainty, WPC progs only offer conservative system representation at this time. Schichtel Bullet points from the WPC Days 3-7 Hazards chart can be found at: https://www.wpc.ncep.noaa.gov/threats/threats.php - Heavy precipitation for parts of the Alaska Panhandle and mainland Alaska, Sun-Mon, Apr 21-Apr 22. - Heavy precipitation for parts of the Alaska Panhandle, Tue-Wed, Apr 23-Apr 24. - High winds for parts of the Alaska Panhandle and mainland Alaska, Sun Apr 21. 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