Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 714 PM EDT Sun Apr 25 2021 Valid 12Z Thu Apr 29 2021 - 12Z Mon May 3 2021 ...Weather Pattern and Model Guidance... The forecast period begins on Thursday with a closed upper low over western Alaska, a weakening low over the Gulf, and a large low passing south of the central/western Aleutians. The upper low/trough lingers over the Alaska mainland going into next weekend. Meanwhile, the Aleutian low should continue slowly eastward near 45-50 degrees north and reach the northern Gulf by next Monday. The 12Z deterministic guidance agrees well on the overall synoptic scale pattern through next weekend, with the normal timing and amplitude differences in individual lows and shortwaves. The GFS remains more amplified with the first disturbance crossing the Gulf for Friday/Saturday, but is in good agreement with the ECMWF on the next system on Sunday/Monday, with the CMC a bit slower. The greatest uncertainty resides across the Bering Sea and eastern Siberia regarding a separate shortwave pivoting around the upper trough over western Alaska. The WPC forecast leaned toward a blend of the 12Z ECMWF/CMC/GFS for the Thursday through Saturday time period, and then more of the EC/GEFS means beyond that. ...Sensible Weather... Temperatures are expected to be on the cool side for many areas under the influence of the upper level trough and mostly cloudy skies, with highs generally in the 40s for most of the mainland, and still remaining in the 20s north of the Brooks Range. Widespread subfreezing lows are also expected for most of the state, but nothing appears record breaking for now. The best precipitation prospects will be from the Kenai Peninsula to the southeast panhandle through Friday, and then across the Aleutians and the Alaska Peninsula/Kodiak Island as the next storm system approaches. Hamrick Additional 3-7 Day Hazard information can be found on the WPC medium range hazards 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