Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 742 PM EDT Thu Apr 11 2024 Valid 12Z Mon Apr 15 2024 - 12Z Fri Apr 19 2024 ...Synoptic Overview, Guidance Evaluation, & Preferences... An upper level ridge axis will likely be in place across the eastern mainland and into the southeast panhandle region for the beginning of next week. Meanwhile, a storm system over the North Pacific tracks in the general direction of the AK Peninsula by Wednesday and brings a return to more rain and snow for southern coastal areas of the state. Meanwhile, a second low pressure system is forecast to track across the Bering and weaken with time. The 12Z model guidance suite features sub-par levels of agreement as early as Monday, and these differences only grow in magnitude over the course of next week. The CMC is most out of alignment across the Bering Sea region with more surface high pressure over that region through midweek, whereas the model consensus favors low pressure. Upon examination of the ML guidance from the ECMWF, there is some support for the stronger GFS solution over the Bering early in the period, and this also holds true for the Pacific low lifting northward towards the AK Peninsula. The UKMET is also fairly close to the ML and GFS guidance, so the model blend was based on a UKMET/GFS/ECMWF blend as a starting point through Wednesday, and then increasing percentages of the GEFS mean (the EC mean is likely too far south with the low over the Pacific) to close out the work week. Given the below average confidence in the guidance, changes in the forecast are nearly a certainty in future updates. ...Weather/Hazards Highlights... Coastal rain and mountain snow is likely to increase going into the Wednesday-Thursday time period from Kodiak Island to the Prince William Sound region as moist onshore flow increases ahead of the Pacific low moving northward, and the QPF forecast has trended higher compared to yesterday. However, there are major timing differences in the guidance and the onset of the heavy precipitation is subject to change. Depending on the tightness of the pressure gradient, strong winds could also be an issue for portions of the AK Peninsula and extending eastward to the Kenai Peninsula. Temperatures are expected to be cold to start the forecast period across most areas, but gradually moderating through the week with the upper level ridge building in over the eastern mainland. 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