Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 247 PM EDT Sat Apr 06 2019 Valid 12Z Wed Apr 10 2019 - 12Z Sun Apr 14 2019 Deep troughing well southwest of the Aleutians on Wednesday (500mb height anomaly around -3 stnd dev) will lift northeastward into the Bering as ridging builds ahead of it into the Gulf and eastern interior portions of Alaska. This will help strengthen a system well down into the 960s mb, reaching peak intensity as it crosses the Aleutians. Strong winds 40-50 kts are likely. Upper pattern will largely split the system into the decaying parent low in the Bering and triple point low with the frontal system into the Gulf, spreading rain/snow to the AKPen, Southcentral, and eastward into the Panhandle. The North Slope and eastern interior will stay largely quiet and precipitation-free. The ensembles were mostly aligned through the period and were close to continuity, so used that as a starting point for the forecast. The 00Z ECMWF was closest among the deterministic models, followed by the Canadian and GFS in various stages. The evolution of the multi-shortwave conglomerate early in the week will act to modulate how the deeper system tracks into the Bering Sea, but opted to maintain a somewhat simpler frontal analysis for now. Next system of interest would be next weekend out of the central Pacific and across the western or central Aleutians and into the Bering Sea. 00Z ECMWF/GFS and 12Z GFS/FV3 GFS were either close to or surrounded the ensemble consensus. Upper ridging should still hold in place from the Yukon northwestward into the Beaufort Sea. Fracasso Bullet points from the WPC Days 3-7 Hazards chart can be found 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