Alaska Extended Forecast Discussion National Weather Service College Park MD 743 PM EDT Fri Aug 8 2025 Valid 12Z Tue 12 Aug 2025 - 12Z Sat 16 Aug 2025 ...General Overview... A rather active weather pattern develops across much of western Alaska and the Aleutians going into Tuesday and Wednesday. An amplifying upper trough over the Bering, and two separate surface lows ahead of it, will likely result in heavy rain from the central Aleutians to the western Brooks Range. The southern low crosses the southern mainland to the northern Gulf by Thursday, and the northern low tracks near the Arctic Coast, with a cold front crossing the Interior and North Slope region. A quieter weather pattern should then settle in across most of the state by the end of next week. ...Guidance Evaluation/Preferences... The 12Z model guidance suite initially has some differences across the Gulf region for Tuesday, with the GFS more amplified with the upper trough reaching the British Columbia coast, but otherwise decent agreement across most of the mainland. By Thursday, the CMC becomes stronger with a second shortwave trough crossing the Bering and likely becomes too strong over the Gulf by Friday. Model spread becomes much worse by Friday night into Sunday across most of the domain with large longitudinal differences in trough placements, and therefore the ensemble means accounted for about 70% of the model blend by that time with low confidence. ...Weather/Hazards Highlights... An incoming surface low from the Bering in combination with a cold front approaching from eastern Siberia will result in an enhanced fetch of moist southerly flow across western mainland Alaska early next week. Moisture flux oriented towards the terrain across this region will lead to heavier rainfall across portions of the Seward Peninsula and extending north to the western Brooks Range, and a heavy rainfall area has been added to the WPC hazards graphic for the 12th and 13th where the best model signal is for the heaviest rainfall. Elsewhere, moderate to locally heavy rainfall will also be possible across portions of the central Aleutians and the southwestern mainland. Improving weather conditions compared to the short range period can be expected for southeast Alaska as the rainfall becomes lighter on Thursday and then tapering off by Wednesday. Temperatures should generally be within 10 degrees of climatological averages for most areas next week. 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