Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 756 PM EDT Thu Sep 29 2022 Valid 12Z Mon Oct 03 2022 - 12Z Fri Oct 07 2022 ...Overview... Upper ridging is forecast to dominate the pattern over Southeast Alaska through much of next week causing warming temperatures there, as well as likely dry conditions in the Panhandle Monday-Tuesday before increasing chances for rain later in the week. Farther west, expect a more active pattern as a midlatitude upper/surface low in the Bering Sea Monday pushes southeastward into the northern Pacific, before a larger scale Arctic trough and low pressure system edge toward northwestern Alaska late week. ...Guidance/Predictability Assessment... The initial low in the Bering Sea for the early part of the forecast period Mon-Tue already shows some differences in the model guidance. The 12Z GFS and UKMET show solutions that split the mid-upper energy with part tracking northeast and part south, while the ECMWF takes most energy to the south, and the CMC stays more phased with the energy. The ensemble means are much like their deterministic counterparts, and the associated surface lows show a wide variety of solutions in terms of position and strength. The WPC forecast leaned more toward the ECMWF/CMC type solutions but did include some of the GFS (including the 06Z run) and GEFS mean as a balance for this feature in the first half of the forecast period. Model guidance is at least more agreeable with the mean ridge axis extending northwest from British Columbia across the Panhandle next week. Models also show that a shortwave may come across interior Alaska Wed-Thu, with some variety in timing, but the larger scale trough shows better consensus as it edges toward northwestern Alaska along with a possibly strong surface low for the latter half of next week. The forecast blend later in the period favored the EC/GEFS ensemble means along with some ECMWF/CMC components. ...Weather/Hazards Highlights... A weakening surface low pressure system (from energy that was once Kulap in the western Pacific) could cause some lingering precipitation from the Kenai Peninsula eastward into Southcentral Alaska Monday. Light to moderate precipitation is possible across the Aleutians and the Alaska Peninsula along with perhaps some light showers across the western side of the state due to the midlatitude low. Increased moisture inflow and the lingering low pressure system in the northern Pacific for the latter half of the week could enhance precipitation across Southcentral and possibly into the Panhandle. Coverage of light to moderate precipitation could increase across Interior Alaska Thursday and Friday ahead of the upper trough. The likely strong surface low could lead to the potential for high winds for the northwestern interior, particularly along the coast. The bulk of Alaska will see low temperatures above normal through the medium range period, with more of a mix for highs. Above average highs are likely to be seen across the interior between the Brooks and Alaska Ranges, with pockets of below average highs within those ranges and for the southern part of the state through early next week. These areas, along with the North Slope, are forecast to warm to above normal by midweek and beyond. Tate Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sun, Oct 2. - High winds across portions of mainland Alaska, Thu, Oct 6. 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