Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 614 PM EDT Mon Jun 01 2020 Valid 12Z Fri Jun 05 2020 - 12Z Tue Jun 09 2020 ...Overview and Guidance/Predictability Assessment... Quasi-zonal flow across much of the North Pacific will encounter a pair of upper lows near Alaska later this week. Low over the Bering Strait is forecast to sink southeastward into next week as a persistent upper high slowly retreats into the Canadian archipelago. To the south, a system over the North Central Pacific will lift northeastward and perhaps interact with the Bering upper low moving across Bristol Bay. The models/ensembles were in good agreement through about 24 hours ago but have departed a bit from a consensus. This stemmed from the handling of both the northern stream upper low and the mid-latitude system and how they may interact (and at what longitude). Preferred to stay near the larger 12Z consensus and continuity rather than the 00Z ECMWF ensemble mean which shifted abruptly westward with the Pacific system in line with its deterministic counterpart at 00Z. With a farther east 12Z ECMWF, used the 12Z GEFS to smooth out some timing/track differences but added some detail with the 12Z Canadian that kept the system on an eastward trajectory until next Mon/Tue when it may attempt to lift into the Gulf. Confidence was no better than average given the model/ensemble changes. ...Weather Hazards/Threats... Near to above average temperatures will remain for northwestern mainland Alaska to the northeast of the upper low. That will bring cooler temperatures to southwestern areas as it crosses Bristol Bay. Weak mid-level flow near the Alaska Range to the Tanana Valley will promote scattered showers and some convection through the period, some of which could be locally modest in amounts. Temperatures will be within several degrees of normal between the Alaska and Brooks Range, but near to below normal over Southcentral to the Panhandle. By next week, the system over the central North Pacific will spread at least more cloudiness toward the coast but at this point appears to keep most rain over the water, except for maybe parts of the southern Panhandle. 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: - Much above normal temperatures across portions of northwestern Alaska, Thu, Jun 4. 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