Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 743 PM EDT Mon Apr 28 2025 Valid 12Z Fri 2 May 2025 - 12Z Tue 6 May 2025 ...General Overview... The first days of May are expected to be rather unsettled in terms of expected weather conditions from the Alaska Peninsula to the southeast Panhandle, courtesy of multiple low pressure systems and moist onshore flow from the Gulf. Aloft, a broad upper low is expected to be in place across the Bering for the end of the week, and then pivoting to the Gulf by Sunday and into early next week. Meanwhile, the Arctic surface high will continue to be strong and result in sustained polar easterlies north of the Brooks Range, and below average temperatures in many cases. ...Guidance/Predictability Assessment... The 12Z model guidance suite features good overall model agreement for the end of the week, and therefore a deterministic model blend suffices as a good starting point in the forecast process. Looking ahead to next weekend, timing and location differences have narrowed compared to yesterday with the second system approaching the Gulf region. Similar to yesterday, there has been a northwestward trend in the guidance with that low over the past couple of days of model runs. By the end of the forecast period next Tuesday, the guidance is in very good agreement for a day 8 forecast with the Gulf low, but varies much more across the western Bering, with the CMC a stronger outlier with the next low near Siberia. The ensemble means were increased to about half by this time, mainly owing to the uncertainties over the western portion of the domain. ...Weather/Hazards Highlights... Late season heavy rainfall is still expected from eastern portions of the Alaska Peninsula to the Prince William Sound region for the end of the week, but this should be abating in intensity going into Friday as the low weakens. It will unfortunately remain rather unsettled for the southern coastal areas with damp onshore flow continuing and periods of rain and mountain snow. With the following storm system over the Gulf next weekend, there will likely be a return of additional rainfall for the southern coastal areas and extending to the southeast Panhandle, but currently not expected to reach hazardous levels with that event. A quasi-stationary frontal boundary draped across the Interior for most of the forecast period will separate a mild and spring-like airmass across south-central Alaska, from a much colder and polar-like airmass from the Brooks Range northward. Temperatures are generally expected to be below average with the Arctic surface high continuing to govern the overall weather pattern. 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