Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 614 PM EST Thu Jan 02 2020 Valid 12Z Mon Jan 06 2020 - 12Z Fri Jan 10 2020 Upper ridging is forecast to rebuild over eastern Asia (near the Amur river or along the Russia/China border) with additional ridge building in the lower mid-latitudes south of the Gulf of Alaska. Combined with a weakening upper high in the Beaufort Sea, this favors a slow erosion of lower heights over the interior amid a fairly progressive flow out of the North Pacific. The models and ensembles have struggled with system timing in the quickening flow but overall aligned adequately. Relatively larger spread (though nominally smaller compared to later forecast times) existed at 2-3 days out with lower amplitude short waves over the North Pacific. This will carry a couple areas of low pressure toward and into the Panhandle Mon/Tue. The 12Z GFS favored the trailing low while the 12Z ECMWF/Canadian/UKMET favored the leading low which was the preferred route (though the Canadian was notably farther north). Once that system exited into British Columbia, focus shifted to the Bering Sea. Next system will likely come in phases, the first of which will be a triple point low headed toward the Gulf but likely weakening on Wednesday, then perhaps another front or two rotating under the old parent low. Ensembles show a good deal of spread with any system after next Wednesday so opted to carry each along at a reasonable forward speed. Any of the GFS/ECMWF/Canadian runs was plausible, but were simply used for just a bit of detail. Cold temperatures will ease with time as height slowly rise, but staying below average for early January. Rain/snow will focus along the Aleutians eastward to the Panhandle but will generally be light to modest amounts. North of the Alaska Range may be precipitation-free. Fracasso 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 Hazards: - Much below normal temperatures across portions of mainland Alaska, Sun-Tue, Jan 5-Jan 7. 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