Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 759 PM EDT Mon Mar 11 2024 Valid 12Z Fri Mar 15 2024 - 12Z Tue Mar 19 2024 ...General Overview... An amplified upper level flow pattern is expected to be in place across the Alaska domain for the end of the week and extending into next weekend. A upper trough initially over the western half of the mainland will weaken and this will equate to warming temperatures after a very cold start this week. Meanwhile, an elongated upper ridge axis with developing closed higher over eastern Siberia, and a building ridge axis over western Canada, will tend to result in a rather blocky pattern over the central and northern portions of the domain. A few surface lows will track eastward towards the Gulf region and produce rounds of unsettled weather from the Alaska Peninsula to the southeast Panhandle, with heavy precipitation expected from the Kenai Peninsula to the St. Elias Mountains on Friday and Saturday. ...Guidance Evaluation and Preferences... The 12Z model guidance suite features decent overall agreement among the GFS/ECMWF and their ensemble means through most of the forecast period. The 12Z CMC has trended closer to the model consensus compared to yesterday's 12Z run that was farther east with the trough over the mainland and suppressed the western Canada ridge much more. Given increasing uncertainty in subsequent surface low evolutions across the North Pacific and Gulf, the ensemble means accounted for about half of the forecast blend by next weekend. ...Weather/Hazards Highlights... Multiple rounds of moderate to heavy rain and mountain snow are expected from the eastern mountains of the Alaska Peninsula to the southeast Panhandle during the extended forecast period. The period of heaviest coastal rain and mountain snow is expected Friday and lasting into Saturday evening, where strong onshore flow coupled with orographic forcing will likely result in a few inches of QPF during this time. Temperatures for a vast portion of western and especially northern Alaska will start off quite chilly to end of the week, but a return to milder conditions will be expected by Sunday and early next week as highs rebound back into the 20s and 30s for most Interior locations south of the Brooks Range, and 30s to mid 40s near the southern coastal areas. 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