Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 509 PM EST Tue Jan 28 2020 Valid 12Z Sat Feb 01 2020 - 12Z Wed Feb 05 2020 ...Some moderation in temperatures next week... ...Low pressure system to bring windy/rainy conditions to the Aleutians... A well-defined system (sub-960mb) will move into the Bering next week and unravel to the east. The models have showed this evolution with increasing heights to the mainland for several days. However, uncertainty in the forecast ramps up after Sunday due in part to how much northern stream energy either slips westward/ southwestward near the Bering Strait or splits eastward or northward atop upper ridging. The ECMWF fell in the former camp while the GFS in the latter, but the ensembles mostly clustered near their parent model. Opted to favor the ECMWF a bit over the GFS as the Canadian/UKMET were closer to the ECMWF. Nevertheless, could not rule out any scenario as upper ridging could be underestimated as it surges northward. This would affect the possible sfc low into western areas that may be overdone in the ECMWF guidance, and as such showed a weaker version of this. Favored upper pattern suggests triple point development into the Gulf around Monday as the front continues eastward. Could see shortwaves develop around the decaying Bering upper low that may or may not help to slow the front via sfc wave development, which was a scenario showed by all the deterministic runs though at various points in time. Ensembles show weakening troughing in the Bering by the end of the period as another system may enter from the west. Temperatures will moderate from 15-25 below average to within several degrees of average over much of the interior, from south to north, as southerly flow strengthens. Models may be too quick to erode the cold air mass in place so trended a bit slower to raise temperatures than the NBM. Precipitation will be favored along the coast from the Aleutians across to the Panhandle where several inches of rain (some onset snow) are possible along the coast and southeastward-facing areas (Kodiak, Kenai peninsula) but much more favored for the Panhandle by later in the period. Fracasso Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php Hazards: - Heavy precipitation across portions of the Alaska Panhandle, mainland Alaska, and the Aleutians, Fri-Mon, Jan 31-Feb 3. - High winds across portions of mainland Alaska and the Aleutians, Sat-Sun, Feb 1-Feb 2. - Much below normal temperatures across portions of mainland Alaska, Fri-Mon, Jan 31-Feb 3. 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