Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 509 PM EDT Fri Jul 05 2024 Valid 12Z Tue Jul 09 2024 - 12Z Sat Jul 13 2024 ...Overview and Guidance Evaluation/Preferences... Forecast spread and uncertainty with embedded systems and interactions have increased through medium range time scales despite a still reasonably similar larger scale pattern evolution. Continuity is best maintained with a larger focus on the more cycle to cycle consistent ensemble means, with only limited model input for days 4-8 detail, but the main general weather related guidance trends from the last few days remain in play to further monitor. Accordingly, the WPC product suite was primarily derived from the NAEFS/ECMWF ensemble means, with only small inputs from the 12 UTC GFS/ECMWF/Canadian. ...Weather/Hazards Highlights... A weakening surface front across Mainland Alaska should provide some focus for local precipitation next week, with higher totals likely associated with higher terrain given an overall pattern with favorable upper support. Much of Alaska remains generally wet and unsettled, which should help bring some relief to wildfire activity. For early next week, rain and storms will spread from Southwest Alaska through the Alaska Peninsula to SouthCentral as Gulf moisture gets pulled northward ahead of now less certain northern stream upper troughs/systems progression over the mainland. A heavy rainfall/runoff issue threat may be as moisture feeds inland into favored south facing terrain of the Alaska Range where some spots could see 1-2" totals, especially on Monday. Given overall upper troughing over the state into next week, daytime highs across nearly all of Mainland Alaska will be well below normal, with the greatest anomalies across western and northern parts of the state. Temperatures may begin to moderate mid-later next week. There is also still some threat to lift organized low pressure/frontal systems up across the Gulf of Alaska early-mid next week. This track would support unsettled maritime conditions over the Gulf and offer potential for moderate to heavy rainfall from southern Alaska through the Southeast. The main focus may develop from eastern southern Alaska through northern Southeast Alaska next Tuesday and Wednesday, but the signal is guidance has not increased from earlier runs. Later period system activity guidance support is less than uniform in guidance, but the preferred ensemble means do still show an amplified and slowly evolving larger scale pattern with a major closed upper low/trough centered over the Bering Sea and an emerging upper trough over the Gulf of Alaska as ample energy feeds downstream to fuel cyclo/frontogenesis. In this scenario, heights rise over-top into the eastern Mainland. While specifics are currently lacking in certainty, this pattern would seem to favor a continued wet and system active period from West/Southwest Alaska through the southern Alaskan tier through mid-later next week as organized/unsettling systems will be prone to develop and evolve/linger over the eastern Bering and downstream into the Gulf of Alaska to monitor over the coming days for better clarity. Schichtel 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