Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 725 PM EDT Thu Sep 21 2023 Valid 12Z Mon Sep 25 2023 - 12Z Fri Sep 29 2023 ...Overview and Guidance Evaluation/Preferences... Strong upper ridging in the mid-latitudes of the North Pacific south of the Aleutians will promote a fast jet stream along and south of 50N next week, with deep troughing well southeast of the Gulf of Alaska easing in time. Troughing is favored over northeastern Russia extending southeastward across the southwest mainland which will maintain a drier than normal pattern. By the end of next week, ensembles start to signal a system moving out of the central North Pacific toward the Aleutians. The guidance was in good agreement overall with the relatively progressive pattern west of the Gulf, though the 12Z GFS was a bit strong with a mid-week wave that arced just south of the central Aleutians. Preferred the flatter/weaker majority that fit with continuity. This was led by the 12Z ECMWF with support from the Canadian most of the time. By the end of the period, the GEFS mean and ECMWF ensemble mean showed good clustering with low pressure approaching the Aleutians and perhaps moving into the eastern Bering Sea. The 19Z NBM was a good starting point for the sensible weather grids. ...Weather/Hazards Highlights... Little to no rain/snow is expected over the majority of the interior/mainland this period. Depending on the proximity of the low southwest of Haida Gwaii, the southern Panhandle may see a bit more rain early in the week. With the approach of the central Pacific system, light rain should overspread the Aleutians later next week. Temperatures are forecast to be within several degrees of typical values for late September, with highs generally in the 40s/50s and lows in the 20s/30s. Fracasso 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