Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 604 PM EST Sun Dec 08 2019 Valid 12Z Thu Dec 12 2019 - 12Z Mon Dec 16 2019 Upper ridging will meander over the Arctic Ocean which will favor reinforced/reinvigorated troughing to its southwest out of the Bering Sea. The storm track will be fairly progressive but not without wound-up/robust surface systems. The first system of interest will be a dying low near Kodiak Thu per the consensus of the 12Z ECMWF/UKMET/Canadian as the GFS remains the only one to move a coherent surface low from the occlusion into Bristol Bay. Weak system will slide underneath the dissipating surface low into southern BC as another system moves through the Bering east-southeastward through the Aleutians. Consensus from the models (even the 12Z GFS there) sufficed until about late Saturday. Thereafter, the ensembles favored low pressure in the eastern Bering/Bristol Bay while the deterministic models (except the GFS) took low pressure south of the Aleutians. Though some triple point development may ultimately warm the front's orientation, opted to maintain a simpler progression with the old parent low weakening over the eastern Aleutians with the triple point moving into the Gulf. Ensembles were steady with timing for this cycle. Yet another system may move into the western Bering around next Monday but with little agreement seen in the models as of yet. Temperatures will largely be near/above average with a southerly component to the flow and near/above average heights and low level temperatures (850mb temperature anomalies about +1 to +2 sigma). There should be a trend back toward more typical December values by next week over at least the interior. Precipitation will be focused along the coast from Southcentral to the Panhandle around the lead weakening occlusion and trailing upper trough. Some rainfall could be heavy along the coast ending Thursday before a drier pattern between systems. Expect a renewed precipitation uptick next Sun/Mon. 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 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