Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 446 PM EDT Tue Mar 14 2023 Valid 12Z Sat Mar 18 2023 - 12Z Wed Mar 22 2023 ...Overview/Guidance Evaluation/Predictability Assessment... A deep layered low with low pressure systems swirling around the northeast Pacific begins the forecast period. With time, troughing from eastern Asia moves across the Bering Sea into western AK. Mid-level ridging holds firm across eastern AK. Broadly, the guidance is in good agreement on this scenario. But, details regarding system strength (system moving into the Bering Sea) and location (lows circling about south of AK) argues for a consensus/intermediate approach. The 500 hPa heights, pressures/fronts, and winds were based on a compromise of the 12z GFS, 12z ECMWF, 12z UKMET, and 12z Canadian early before using up to 40% of the ensemble means (ECMWF & NAEFS) later in the period to deal with the uncertainty. The QPF was based on a compromise of the 19z NBM weighted towards the 12z ECMWF, 12z GFS, and 12z UKMET. The rest of the grids were 19z NBM based, as usual. ...Weather/Hazard Highlights... Rain, possibly still heavy, should start out the period in southeast and south-central AK with the best chances for such remaining along the southern periphery of the state through the period, with another skirmish with moderate to heavy rainfall expected in about a week. With the strong system moving through the Aleutians into the Bering, gale to possibly storm force winds are expected from the 19th into the 22nd. The forecast pattern evolution in advance of this storm supports a warming trend across mainland AK. Temperatures should still be well below normal over interior through southwestern mainland areas late this week into the early weekend. The North Slope should be above normal at that time and at least low temperatures may be above normal over the Panhandle and southeast corner of the mainland. Expect most areas to be above normal by early next week, aside from the southern Panhandle possibly staying below normal for highs. The North Slope will likely see the warmest temperature anomalies, though high temperatures are forecast to be in the teens. Roth Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Fri, Mar 17. - Much below normal temperatures across portions of mainland Alaska, Fri, Mar 17. 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