Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 234 PM EDT Sat May 04 2019 Valid 12Z Wed May 08 2019 - 12Z Sun May 12 2019 Today's models and ensembles still show a blocking pattern through the middle of next week with a high amplitude Bering Sea trough extending across the Aleutians into the north Pacific and resultant high amplitude ridge across the northeast Pacific and southeast Alaska. Towards the end of next week, the models start to diverge with the number and placement of vortices rotating around the Bering Sea trough and resultant placement of lows in the Bering and adjacent western AK. The 06z GFS and 00z ECMWF show a deep cyclone developing over the northeast Pacific 00z Fri that then moves north onshore later Fri to early Sat. The 00z Canadian lagged several hours behind the GFS/ECMWF, with enough spread in the ensembles to support a weaker system. Next weekend, the spread among where low pressure develops over the Bering Sea, northeast Pacific and adjacent southern/western AK grows large, with confidence plummeting due to little overlap of where low pressure centers are located next weekend. Also, the ECMWF and GFS have made significant run to run changes. Consequently, preferred to rely on a consensus of the 12Z GFS/00Z ECMWF and their ensemble means given the lack of agreement. Temperatures will be warmer than normal over southeast AK through most of the upcoming week due tot he strong upper ridge and corresponding warm temperatures that remain well above normal. Precipitation will focus over the southern coastal areas Wed-Thu, with low pressure along the west coast fostering showers moving inland. Locally heavy rain may be possible in upslope locations. The rain may redevelop over the upper Aleutians to Kodiak Island and southwest AK Fri into the weekend if the stronger lows in the 00z ECMWF and 06z GFS verify, as well as the 12z GFS. Petersen 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