Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 537 PM EST Fri Jan 08 2021 Valid 12Z Tue Jan 12 2021 - 12Z Sat Jan 16 2021 ...Deep lows to bring heavy precipitation and wind/waves from the Gulf of Alaska to Southern/Southeast Alaska Early Next Week... ...Guidance/Uncertainty Assessment... The large scale pattern was reasonably clustered through the period with the WPC blend initially blended with the 12Z ECMWF/CMC/UKMET/GFS and is expected to feature closed lows and/or troughing confined to the Gulf of Alaska west across the Aleutians. A pair of stronger/deeper lows is forecast during the period. The first will be ongoing at the start of the period and has decent clustering between the various models. Over time, typical model spread increases but by day 7/8, guidance suggests another shortwave trough will swing through. At the surface, low pressure is forecast to track across the Gulf and could bring hazardous weather by the end of the forecast period. But because of the higher model uncertainty, the WPC blend favored the ECENS/GEFS at this time. ...Weather/Hazards Highlights... The latest guidance continues to suggest a deep cyclone / closed upper trough over the Gulf of Alaska late this weekend into the early part of next week. This anomalous moisture fetch will favor heavy precipitation and high winds/waves from the Gulf toward the southern/southeast Alaska with the threat transitioning mainly to southeast Alaska by mid-week as the low weakens/occludes. After a brief break, another deep low is forecast to lift into the northern Gulf of Alaska and potentially could bring another round of heavy precipitation, significant waves, and high winds. Though given the lower than average model agreement and higher forecast uncertainty, there is still quite a bit of details left to discern. This pattern should also favor some much above normal temperatures into the Interior next week. Taylor 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 and mainland Alaska, Mon, Jan 11. 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