Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 706 PM EDT Thu Mar 28 2024 Valid 12Z Mon Apr 01 2024 - 12Z Fri Apr 05 2024 ...Guidance Evaluation and Preferences... The pattern over Alaska during the extended range (Monday-Friday) should be fairly progressive, first featuring an elongated trough and embedded systems through the Gulf/Southeast Monday-Tuesday. After this, strong ridging should build over the region on Wednesday-Thursday before another system begins to impact the Mainland by Wednesday. There is good consensus on this overall pattern through about the first half of the period, allowing for a combination of the deterministic model solutions. Uncertainty begins to increase especially Wed-Thurs with the next system into the Bering Sea. The ECMWF is fairly slow with the parent upper low through the far western Aleutians as multiple weaker shortwaves rotate around the main low into the Bering/western Alaska. The GFS and CMC (with some support from the EC-initialized AI model and ensemble means) maintain an elongated trough through the Bering. By Day 8/Friday, the GFS and ECMWF become more out of phase with each other with the EC showing ridging over the Gulf and the GFS, CMC, and ensembles, showing more troughing. After Tuesday, the WPC blend began including/incrementally increasing weighting of the ensemble means through the end of the period. Overall, this maintains good continuity with the previous WPC forecast. ...Pattern Overview and Weather/Hazards Highlights... Coastal impacts, including high wind/waves and flooding, should be coming to an end by the end of the weekend along with heavy snow threats over the Alaska range as a potent storm exits the state. A trailing system behind this across the Gulf into early week will keep some threat for unsettled/wet conditions along the coast, with gusty Gap winds likely on the backside of the surface low. Moderate to locally heavy rain may be possible for parts of the Panhandle on Tuesday. Precipitation will increase again Wednesday-Friday first over western Alaska and extending into the Interior and again the Southern Coast. None of this precipitation looks particularly hazardous at this point. Well below normal temperatures will progress west to east Monday-Tuesday across the state, moderating thereafter, except for the Southeast where daytime highs look to stay below normal most of the period. By next Friday, much of the state should be near or within a few degrees of normal. The North Slope region though, could be 10-20 degrees above normal next Thursday-Friday. Santorelli 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