Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 513 PM EDT Sun Apr 3 2022 Valid 12Z Thu Apr 7 2022 - 12Z Mon Apr 11 2022 ...Overview... A deep upper level trough and closed low is expected to be in place across western Alaska and the eastern Bering on Thursday, and a weakening surface low will affect southeastern portions of the state. By Saturday, the polar low continues to govern the weather pattern across the North Slope region, while an upper ridge axis tries to build in across the Aleutians and the southern Bering, and a second Gulf low likely develops and tracks in the general direction of the southeast Panhandle region. There is also a model signal for a low pressure system approaching the Aleutians by the beginning of next week. ...Guidance/Predictability Assessment... The 12Z model guidance suite continues to show fairly good synoptic scale agreement with the overall pattern through the end of the week, and a general deterministic blend represents a good forecast starting point through Friday. The 12Z CMC is considerably closer to the model consensus compared to its previous 00Z that was more out of phase across the Aleutians and Bering. By the weekend, models struggle with shortwave energy crossing the northern periphery of the Aleutians upper ridge, with the 12Z ECMWF considerably faster compared to the GFS and CMC. There is also a good deal of longitudinal spread in the main polar low by Sunday, but there is still decent agreement on the upper ridge in place across southwest Alaska. Due to these uncertainties in the later half of the forecast period, the WPC forecast leaned increasingly more towards the ensemble means to help mitigate these differences. ...Weather/Hazard Highlights... A corridor of moderate to locally heavy coastal rain and mountain snow between the Kenai Peninsula and the Alaska/Yukon border should be abating by early Thursday as the Gulf low steadily weakens. However, another round of organized precipitation (mainly light to moderate) is likely for the southeast Panhandle region Thursday night into early Friday as a second low approaches the region. Patchy areas of light snow are likely across southern portions of the Interior going into the weekend, and mainly dry conditions farther north. Depending on the eventual evolution and track of the next low reaching the Aleutians by next Sunday/Monday, widespread showers and some gusty winds can be expected for these islands. Most of central and eastern Alaska will likely have readings slightly above normal for the beginning of the extended period and below average for the western mainland. A gradual cooling trend appears likely across much of the mainland going into next weekend as the polar trough over northern Alaska keeps readings in check. Temperatures should also be generally a bit below average for southern coastal areas owing to increased cloud cover and precipitation. Hamrick 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