Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 609 PM EDT Sat Aug 06 2022 Valid 12Z Wed Aug 10 2022 - 12Z Sun Aug 14 2022 ...Very cold and wet pattern for August setting up over much of Alaska through next midweek, especially the North Slope/Interior, with rounds of heavy rainfall likely across the South/Southeast... ...Overview... It remains the case that a deep closed low/upper trough with strong height falls 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... Forecast confidence is not bolstered by less than ideal guidance run to run continuity variance related to stream phasing/separation in an active medium range pattern for Alaska. Accordingly, and with an eye toward continuity, blended the 12 UTC ECMWF with the latest GEFS/ECMWF ensemble means. The ensemble means maintain generally lower heights over the mainland for much of next week in a continuing pattern and the 12 UTC ECMWF offers insight on undercutting upper trough/low development and track over the Gulf of Alaska that seems about the midpoint of a cluster of 12 UTC ECMWF/GFS/UKMET/Canadian solutions. ...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 then Kodiak Island/southern Alaskan tier also looks to become more organized by later next week into next weekend 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 into next midweek, 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 20+ degrees below normal and morning low near or below freezing for some places. Temperatures should slowly moderate later next week. Schichtel 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