Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 205 PM EST Sun Feb 10 2019 Valid 12Z Thu Feb 14 2019 - 12Z Mon Feb 18 2019 ...Guidance/Uncertainty Assessment... Latest GFS/ECMWF and GEFS/NAEFS/ECMWF ensemble means overall cluster reasonably well for the upcoming week and the WPC Alaskan medium range forecast product suite was mainly derived from a composite blend. Applied manual adjustments to depict deeper offshore low pressure centers consistent with favorable support aloft in a stormy pattern with above normal forecast predictability. ...Pattern and Weather/Threats Highlights... Expect a deepened leading low/frontal system and lingering rains will exit the southeastern Gulf of Alaska Thursday, cutting underneath a stalled lingering frontal drape pushed just offshore southeast Alaska. In the wake of this system, models and ensembles build an upper ridge with a mean axis over the western half of the mainland. Pattern amplification will tend to force a new upstream series of potentially deep and stormy low pressure systems over the western half of the Bering Sea and Aleutians. This occurs as high pressure builds over the mainland and northwest Canada. Maritime interest threatening high wind/waves and precipitation may be able to work increasingly toward western/southwestern Alaska and the AKpen/Gulf of AK by next weekend contingent on an expected slow eastward shift of the shielding downstream ridge. Schichtel WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can be found at: http://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif http://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml http://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html