Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 440 PM EST Fri Dec 06 2024 Valid 12Z Tue Dec 10 2024 - 12Z Sat Dec 14 2024 ...Heavy precipitation and gales along the southern coast through early next week... ...Gales should be expected in coastal and offshore areas... ...Overview/Guidance Evaluation/Preferences... Model guidance remains consistent and agreeable in showing a mid- to upper-level ridge across mainland Alaska weakening as a trough between the Sea of Okhotsk and the Gulf of AK team up with a retrograding system across northern Canada to cause its erosion. Within the west-to-east trough, the main deep layer lows are expected to be most persistent over portions of the Bering Sea and Gulf of AK/northeast Pacific. While the broad flow is agreeable, detail issues remain with individual cyclones. For the pressures, fronts, winds, and QPF/PoPs, used primarily a compromise of the 12z runs of the GFS, ECMWF, UKMET, and Canadian before including some 00z ECMWF/12z NAEFS means later in the forecast to account for the uncertainty. The remainder of the grids were more 19z NBM heavy, as usual. ...Weather/Hazards Highlights... Deep south to southeast flow should keep south-central AK and Kodiak Island quite wet early, within 5-10" of liquid equivalent/rain expected from late Monday into early Wednesday, before rainfall/precipitation becomes less intense and moves eastward as the Gulf of AK portion of the trough slowly edges east, making the AK Panhandle wet, but not abnormally so. Portions of southern and central AK should be relatively mild early, but the beating down of the mid- to upper-level ridge and the subsequent deeper layer flow becoming more northwesterly should cause the arctic drape/colder air to shift south more toward southern AK by late next week. The general upper troughing near southern AK should keep sea level pressure near to below average statewide. The stormy pattern should offer gales near most coasts and island groups, though there's enough uncertainty on cyclone depth to not be confident in storm-force winds for the time being, but wind gusts could approach such levels. Roth Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook 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