Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 637 PM EDT Fri May 26 2023 Valid 12Z Tue May 30 2023 - 12Z Sat Jun 3 2023 ...Synoptic Overview... A closed upper low over the northern Gulf of Alaska early in the week is forecast to slowly weaken, while a reinforcing shortwave dropping south behind it across the Alaska Peninsula will help to re-establish the closed low again over the same general area of the Gulf going into the middle-end of the week. Upper level ridging builds in across the Aleutians and the Bering for the Wednesday to Friday time period ahead of the next low pressure system approaching from the general direction of the Kamchatka Peninsula. Meanwhile, a polar cold front associated with an arctic trough is forecast to drop south from the Arctic and bring slightly colder weather for the Brooks Range and points north by midweek. ...Guidance Evaluation/Preferences... The 12Z model guidance suite is in good overall agreement on the main synoptic scale features through next week, with generally above average confidence through about Thursday for most areas. Some timing differences become apparent with the 12Z GFS across the Gulf as the second shortwave builds southward, and it is displaced to the west of the model by late Wednesday onward, but generally more agreeable across mainland Alaska. By next Saturday the CMC differs with a closed low over eastern Siberia that is not reflected in the other guidance, and it is southeast of the model consensus with the low across the eastern Gulf. The fronts/pressures incorporated a general deterministic blend through Wednesday, followed by slightly less of the GFS/ by Thursday and less of the CMC by Saturday, whilst increasing contributions from the ensemble means to about half by that time. ...Sensible Weather and Potential Hazards... Much of the Southeast and southern coast will likely have ongoing light to occasionally moderate showers, owing to the slow moving disturbances over the northern Gulf. However, no areas of significant rainfall or snow are currently expected for this time period. Isolated to scattered showers will be possible across portions of the Interior that will mainly be diurnally driven. Temperatures will generally be cooler than average for most days across much of the mainland, with the greatest anomalies expected across western Interior areas. This will mainly equate to highs 55 to 65 and lows 35 to 45 for most locations. There will likely be some relatively milder conditions across the northern third of the state on Tuesday ahead of the cold front. Hamrick No significant hazards are expected over Alaska during this forecast period. 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