####018003997#### FXAK02 KWNH 192350 PMDAK Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 749 PM EDT Fri Apr 19 2024 Valid 12Z Tue Apr 23 2024 - 12Z Sat Apr 27 2024 ...Deep cyclone will bring very strong/high winds to the western Aleutians early next week... ...Overview with Guidance Evaluation and Preferences... A relatively stagnant synoptic pattern is forecast to prevail in the vicinity of Alaska through next week, with a slow-moving but weakening deep cyclone over Bering Sea coupled with a ridge extending north into mainland Alaska. This will be in stark contrast with a fast west-to-east storm track across the northern Pacific. The deep cyclone over the Bering Sea will likely bring very strong to high winds for at least the western portion of the Aleutians early next week before a gradual weakening of the cyclone is forecast to take place through midweek while it lingers over the Bering Sea. Model guidance is in general agreement with this synoptic pattern through midweek. Toward the end of the week, guidance shows some divergence regarding how long the Bering Sea low will linger and how far east a developing low pressure system from the North Pacific will track toward the Gulf of Alaska and how deep it will turn out to be. A general compromise of the model guidance is adopted (with 40% 00Z/12Z ECMWF, 40% 12Z GFS/GEFS, and 20% from the 12Z CMC/CMC mean) which yields solutions that are quite compatible with yesterday's WPC 500mb and surface prognostic charts. The Day 8 depicts a modestly strong occluded cyclone sliding northeast just off the Alaska Peninsula. ...Weather/Hazards Highlights... The strong storm near the western Aleutians will be the main system of interest early next week as it should gradually trend weaker after Tuesday. This storm should also produce areas of strong winds across at least the western Aleutians and into Bering Sea where a high wind area is depicted on the Hazards map. Meanwhile, a leading front will likely focus higher moisture contents toward the eastern Aleutians and the Alaska Peninsula/Kodiak Island ahead of the occluded front and a triple-point low through midweek. Some of this activity may also be heavy but models are keeping the QPF amounts modest thus far. Surface low/front details over the Aleutians/Bering Sea become more uncertain later in the week but there is a good signal for the general persistence of cyclonic flow with rising pressures. Some lingering precipitation is possible along the southern coast early in the week due to the initial shortwave over/near the southwestern corner of the mainland. The weak system tracking across the northeastern Pacific may bring a period of mostly light precipitation to the southern Panhandle toward the end of next week with a lower confidence due to the model spread. Meanwhile, the guidance spread appears far enough south to keep the Panhandle mostly dry. Most of the state should see above normal temperatures during next week, with the highest anomalies tending to be over the Interior. To the north of a front settling over the central mainland, cold high pressure over the Arctic may keep temperatures near to somewhat below normal across the North Slope. Locations near the Southcentral coast and northern Panhandle may also see near or slightly below normal readings. Kong/Rausch 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 $$