Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 345 PM EDT Fri Apr 05 2019 Valid 12Z Tue Apr 09 2019 - 12Z Sat Apr 13 2019 Somewhat ill-defined upper pattern, with low amplitude waves and modest surface systems, will transition to a more amplified pattern as the bulk of the Pacific becomes dominated by a trough/ridge couplet through the mid-latitudes. This will be instigated by a robust system crossing the Aleutians on Wednesday and will move into the southern Bering Sea Thursday as a powerful sub-960mb low (or perhaps deeper based on some models). This would be near the low end of observed pressure values for April over the central Aleutians. The models have wavered on the lead-up pattern and thus modulated the timing of the more defined midweek system, but overall remain in decent agreement. The 12Z GFS lied on the southeastern side of the spread with the track of the low into the Bering Sea and was only lightly weighted compared to the 00Z ECMWF/ECMWF ensemble mean. Still expect the parent low to weaken near the St. Lawrence Islands as the triple point moves through the Gulf and into the Panhandle. Consensus approach should serve well to minimize future shifts in the evolution. Strong winds (40-50kts) around the low across the Aleutians may stay mostly over the Bering as peak intensity will be realized near the Aleutians. Precipitation will spread eastward through Southcentral as the triple point moves eastward but focused along the coast and especially southern/southeastern Kenai to Yakutat. Fracasso Bullet points from the WPC Days 3-7 Hazards chart can be found at: https://www.wpc.ncep.noaa.gov/threats/threats.php Hazards - Heavy precipitation across portions of the Alaska Panhandle, mainland Alaska, and the Aleutians, Wed-Fri, Apr 10-Apr 12. - High winds across portions of mainland Alaska and the Aleutians, Wed-Thu, Apr 10-Apr 11. 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