Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 221 PM EST Fri Nov 08 2019 Valid 12Z Tue Nov 12 2019 - 12Z Sat Nov 16 2019 Models show relatively good consensus that a deep surface low should approach the Alaska Peninsula Tue-Wed. Timing and some remaining intensity differences among deterministic and ensemble solutions make for moderate confidence, with ensemble means showing central pressure values 15-20 mb higher than their respective deterministic solutions. Given the trend, incorporated a blend of the latest deterministic guidance (ECMWF/CMC/GFS) into the forecast for days 4-5 (Tue-Wed), which resulted in a downward trend in the central pressure of the system compared to the previous forecast (although still not quite as low as shown in the latest deterministic solutions). This low pressure system could produce a variety of impacts, including the potential for high winds and significant waves along the coast. As this system moves inland and weakens Thu-Fri, the upper-level energy, along with additional arctic shortwave energy arriving from the north, are forecast to linger across western mainland Alaska in the form of an upper low through late next week. Model solutions agree on this general concept although solutions differ as to the specific intensity of the upper low. South of this upper low, a stream of small scale but quick moving shortwaves are expected to cross near the Aleutians and toward the Gulf of Alaska. Spread increases through time, but some consensus was noted among ensemble means that another low pressure system should approach southern mainland Alaska by next Fri night or Sat, associated with one of the more significant aforementioned shortwaves. Given gradually increasing spread, a trend to heavier weighting of ECENS/GEFS ensemble means was shown during days 6-8 (Thu-Sat). Ryan Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php - High winds across portions of mainland Alaska, Tue-Wed, Nov 12-Nov 13. - Much above normal temperatures across portions of northern Alaska, Mon-Wed, Nov 11-Nov 13. - High significant wave heights for coastal portions of mainland Alaska and the Aleutians, Tue-Wed, Nov 12-Nov 13. 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