Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 627 PM EDT Fri Jul 2 2021 Valid 12Z Tue Jul 6 2021 - 12Z Sat Jul 10 2021 ...Overview and Guidance/Predictability Evaluation... The deterministic models and the ensemble means are in generally above average agreement on the synoptic scale pattern. North Pacific and western Aleutians shortwave energy will likely merge with a northern Bering Sea upper level low early in the forecast period, followed by the upper low eventually dropping over the Gulf of Alaska. Meanwhile, low-mid level flow around the periphery of a deep Arctic low should begin to lower heights aloft over the northern/western mainland later in the week. This overall pattern evolution will favor a broad coverage of scattered showers next week, with typical model differences regarding placement of heaviest rainfall totals. In terms of model preference, the WPC forecast was primarily derived from a deterministic model blend through Thursday, and then less of the GFS and more of the ensemble means for Friday and Saturday. The GFS becomes more amplified and farther south with the core of the upper low over the Gulf of Alaska compared to the model/ensemble consensus, so less weighting was applied to the GFS for the end of the forecast period. ...Weather/Threats Highlights... The general pattern will support a broad area of moisture overspreading the state with many locations seeing multiple days of scattered to numerous showers. The initial Aleutians/Bering Sea system could also produce some gusty winds, especially over marine and coastal areas. Upstream flow could bring another surface system and precip area into the western mainland late in the week. At this time, the best potential for highest five-day totals would likely be over portions of the southern coast/mainland into the southeast Panhandle. The clouds and rainfall will keep high temperatures below normal over most of the state with the coolest anomalies tending to be over the southern mainland. Hamrick/Rausch Hazards: - Much below normal temperatures across portions of southern mainland Alaska, Mon-Thu, Jul 5-Jul 8. 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 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