Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 552 PM EDT Fri Aug 05 2022 Valid 12Z Tue Aug 09 2022 - 12Z Sat Aug 13 2022 ...Very cold and wet pattern for August setting up over much of Alaska, especially the North Slope/Interior, with rounds of heavy rainfall likely across the South/Southeast... ...Overview... A deep closed low will drive a cold front across western/central Alaska and into the Gulf of Alaska early-mid next week, with widespread organized precipitation including terrain/mountain snows become increasingly likely across the Mainland. This system will usher in a much cooler regime across Alaska that now seems more likely to linger through late next week with the reinforcing digging of Arctic stream energies. Meanwhile, yet another protracted period with heavy rainfall potential develops and spreads across southern/southeast Alaska next week. ...Guidance/Predictability Assessment... The 12 UTC GEFS ensemble mean is the most amplified of the means with upper troughing over the mainland next week. However, all ensemble means are less amplified than the 12 UTC GFS/ECMWF/Canadian into later next week, so given the recent nature of the pattern opted to include some model info days 4-8 into a forecast blend with the GEFS mean even though GFS/ECMWF/Canadian embedded system model differences get less pretty over time across the Alaskan domain. This maintains decent WPC product continuity, albeit trending a bit more amplified and colder into longer time frames. ...Sensible Weather... Much of mainland Alaska looks to remain rather unsettled next week as strong systems dig into region. This likely brings protracted periods with gusty winds as well as widespread and locally enhanced precipitation given large height falls/upper support. Some of this precipitation could fall as snow, particularly parts of northwest Alaska and elevated terrain. The heaviest precipitation should shift south and east with time next week, with the potential for heavy rainfall once again returning to parts of south/southeast Alaska and the Panhandle region as low pressure systems focus a plume of long fetch Pacific moisture across the region. Precipitation over the Aleutians/Alaska Peninsula region also looks to become more organized by later next week as a new systems develops/reforms and tracks just to the south of the area across the northern Pacific. Chilly temperatures will overspread much of Alaska, including the Panhandle with daytime highs as much as 10 to 20 degrees below normal. The highest anomalies will feature across the North Slope and into the Interior region though, where anomalies could be as high as 30+ degrees below normal and morning low near or below freezing for some places. Temperatures may begin to slowly moderate from west to east mid-later next week but remain chilly and unsetted for summer. Schichtel Hazards: - Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Mon-Wed, Aug 8-Aug 10. - Much below normal temperatures across portions of mainland Alaska, Mon-Fri, Aug 8-Aug 12. Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook 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