Alaska Extended Forecast Discussion National Weather Service College Park MD 756 PM EDT Wed Jul 30 2025 Valid 12Z Sun 03 Aug 2025 - 12Z Thu 07 Aug 2025 ...General Overview... The primary upper flow features to affect Alaska from this upcoming weekend into early next week will be a weakening low pressure system over the Gulf of Alaska, upper level ridging over the Interior and North Slope region, and closed low/trough emergence over the Aleutians and the Bering Sea. The latter will support development of a well organized southern Bering Sea surface low pressure system into the weekend whose dynamics and triple-point low development affect the North Pacific and the southern coastal areas going into next week. ...Guidance Evaluation/Preferences... There is generally good overall model agreement to begin the forecast period Sunday, and this holds true going into Monday as well. There has been a modest northwestward trend in the guidance overall compared to yesterday with respect to the main Bering Sea low pressure system, with the 00Z ECENS east of the fresh 12Z guidance at the time of fronts preparation. For early next week, the CMC is stronger with an arctic trough that sets up over the general vicinity of northern Yukon, and it also lingers the Gulf low longer than the GFS/ECMWF. The 12Z ECMWF is stronger with a second arctic trough developing over northwestern Alaska by next Wednesday/Thursday, and the GFS has a more defined surface low near the Arctic Coast by Monday. Taking these factors into account, the WPC fronts/pressures forecast was primarily derived from a multi-deterministic model blend on Sunday, and then gradually increased percentages of the ensemble means to about half by next Thursday. Slightly greater weighting was applied to the GEFS mean given its closer agreement with the guidance available at the time. ...Weather/Hazards Highlights... Isolated to scattered afternoon and evening showers and thunderstorms can be expected across the Interior most days. In addition, moist onshore flow ahead of the weakening Gulf low will tend to keep conditions unsettled at times for Southeast Alaska with periods of mainly light rain expected. Heavier rain is likely for portions of the Alaska Peninsula on Sunday, but not considered heavy enough to be hazardous at this time. By next Thursday, there may be some potential for gap winds in the Alaska Range. Warm temperatures are expected across much of the Interior and even across the North Slope going into the weekend and into Monday with an upper ridge axis in place, with highs well into the 70s and even some lower 80s, and lows generally in the 50s. A cold front drops south across the North Slope and settles in the general vicinity of the Brooks Range through the middle of the week, with temperatures falling about 10 degrees or so behind it. 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