Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 414 PM EDT Mon Mar 26 2018 Valid 12Z Fri Mar 30 2018 - 12Z Tue Apr 03 2018 Model guidance today seems to further muddy the water as to how exactly the flow pattern will evolve across Alaska during the medium range period. The GFS and ECMWF/CMC showed differing solutions even on day 4 (Fri) with respect to a shortwave moving from the Bering Sea across southwestern mainland Alaska. The GFS was 12-18 hours faster with the wave. These timing differences resulted in significantly differing solutions by Sun-Mon, with the GFS consolidating the energy into an upper low over the eastern Gulf, and the ECMWF/CMC showing the wave interacting with additional Arctic energy as the Bering ridge builds, resulting in a cutoff low that drifts westward toward the Aleutians. Further, models continue to vary widely from run to run as to the exact character and orientation of the ridge as it amplifies across the Bering from Sat onward. Some solutions have shown the ridge migrating northward to the high latitudes of the Arctic, while others keep the ridge more anchored across the Bering Sea, and still other runs have shown the ridge never becoming fully established, and quickly weakening as a stream of shortwave energy from the north Pacific keeps the flow more progressive. Given these widely differing solutions throughout the medium range period, opted to keep any changes very limited. In terms of sensible weather, rising heights across Alaska will mean gradually increasing temperatures at least into the weekend. Southeast Alaska will see the greatest potential for precipitation on Fri under the influence of a Gulf low pressure system. Meanwhile, ridging will result in relatively dry conditions across much of mainland Alaska. Ryan