Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 729 PM EDT Fri Jun 28 2024 Valid 12Z Tue Jul 02 2024 - 12Z Sat Jul 06 2024 ...Overview and Guidance Evaluation/Preferences... The ensemble means from the GEFS, EC, and CMC continue to provide good to excellent agreement on the evolution of the upper-air pattern across Alaska through the medium-range period. The Rex Block upper-air pattern setting up in the vicinity of Alaska during the short-range period will persist into much of the medium-range period. Models continue to depict an initially deep Bering Sea low will weaken as it slides to the south of an upper ridge that will be anchored across northern Alaska. The WPC medium-range grids for Alaska maintained continuity by utilizing a 40% GFS/GEFS mean, 40% ECWMF/EC Ensemble mean and 20% CMC/CMC mean weighting through the entire extended period. ...Weather/Hazards Highlights... A rainy pattern will linger across portions of the Aleutians and Alaska Peninsula initially as the Bering Sea cyclone gradually slides across these areas before drifting farther to the east or southeast early next week. The terrain in south-central and northern Alaska are expected to have the best chance of showers and thunderstorms nearly each day and with the convection comes the possibility of dry lightning strikes during the afternoons and evenings. This would increase the risk for fire weather concerns given the dry fuels across the region. Ridging across mainland Alaska will maintain warm to hot temperatures. Daily highs are expected to rise into the 80 to 90F range for the most part across the eastern interior sections with mostly 60s and 70s expected across lower elevations of south-central Alaska, 50s and 60s in most coastal areas, 50s and 40s across the North Slope, and mid to upper 40s in the Aleutians. Higher elevations in the terrain across south-central and southeast Alaska should fall below freezing overnight. The North Slope will cool down closer to normal temperatures by Sunday as a surface high pressure system gradually sliding from west to east off the northern coastline of Alaska funnels colder air into the area from the Arctic Ocean. Similar temperatures are expected to last into late next week across mainland Alaska but with a gradual expansion of the coverage of scattered showers and embedded thunderstorms when upper shortwave energy from the Arctic Ocean could penetrate the upper ridge and destabilize the atmosphere. Campbell 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