Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 350 PM EDT Fri Sep 06 2019 Valid 12Z Tue Sep 10 2019 - 12Z Sat Sep 14 2019 The forecast period begins on Tuesday with a broad trough over the eastern Aleutians, and a decaying Rex block over western Canada with an upper level high over the Northwest Territories and a broad low near the Pacific Northwest. By Thursday, a large and occluded low pressure system emerges over the Bering Sea that lingers through the end of the week. The 00Z ECMWF was slightly more progressive than the model consensus with the low crossing the Bering Sea, but closer than what it was yesterday. There was enough deterministic model agreement on the synoptic scale through Thursday, so a blend of the ECMWF, GFS, and CMC solutions served as a good starting point in the forecast process, and more of the ensemble means by Friday and Saturday. In terms of sensible weather, this equates to a rather active weather pattern for the maritime regions and coastal areas of the state, especially the Aleutians and the southern coast of Alaska. Increased moisture advection north of the Gulf low is expected to produce moderate to locally heavy rainfall from King Salmon to the southern Yukon border, including the Anchorage area. Gale force winds are likely across parts of the Aleutians and especially over the Bering sea for the middle to end of the week in association with the big surface low. Temperatures are expected to be mainly in the mid 50s to upper 60s for highs, and mid 30s to near 50 degrees for overnight lows. Hamrick -------------- Hazards: - Heavy rain across portions of the Alaska Panhandle and mainland Alaska, Thu-Fri, Sep 12-Sep 13. 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 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