Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 504 PM EDT Sun Jun 04 2023 Valid 12Z Thu Jun 08 2023 - 12Z Mon Jun 12 2023 ...A stalled deep layer low will continue bringing rain to much of Alaska mid-late week through this weekend... ...Overview/Guidance Evaluation/Preferences... A deep layer cyclone over the eastern Aleutians/Alaska Peninsula will be the main weather feature going into next week/weekend across the Alaska region. With such a blocky pattern and such a large system, there is relatively good model agreement and higher confidence in the bigger picture details. Details around the broad low remain problematic, as the 12z GFS shows the low tracking farther east than the remainder of the guidance. Given the blocky June pattern, a slower track holding the low west may be more likely. As shortwaves round the large low, upper ridging will get beaten down/worn away with time, which allows frontal systems to steadily push eastward across AK. Overall a multi-model deterministic blend of the 12Z GFS/ECMWF/UKMET/CMC was able to be used for the WPC forecast early on in the 500 hPa heights, pressures, winds, and QPF with slowly increasing amounts of the GEFS and EC ensemble mean guidance as the period progressed, while keeping the GFS contribution low. The remainder of the grids are more evenly distributed amongst the deterministic and ensemble guidance, as usual. ...Sensible Weather and Potential Hazards... The heaviest precipitation amounts associated with the stacked low may take place early next week in the short range period when moisture anomalies are highest, possibly channeling moisture from what was Mawar in the western Pacific. Mainly rain is likely, increasingly statewide, though some precipitation could be snow in the highest elevations and some mixed precipitation is possible in the North Slope. Rain amounts over time could accumulate to several inches next week for parts of the Alaska Peninsula and Southcentral Alaska. Warmer than normal temperatures remain in the cards north of the Alaska Range on Wednesday underneath the brief upper ridge, with lows in the 50s and highs in the 70s for the lower elevations of the Interior. Wednesday and perhaps Thursday may be warmer than normal for parts of Southeast Alaska as well before a cooler trend. The upper low and the coincident rain and cloudiness chances should keep high temperatures down below normal along the southern coastal regions. As rain becomes increasingly entrenched across the state, temperatures across the interior should fall back towards average values for early to mid June. Roth/Tate 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