Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 615 PM EDT Sat Apr 20 2024 Valid 12Z Wed Apr 24 2024 - 12Z Sun Apr 28 2024 ...Overview with Guidance Evaluation and Preferences... 12 UTC GFS/ECMWF/UKMET/Canadian model solutions are reasonably clustered with ensembles in a pattern with above normal predictability overall for mid-later next week. This primarily entails the slow weakening and meandering of a main deep low over the Bering Sea and the building of a warming upper ridge over the mainland, albeit with uncertain weaknesses aloft down toward Southeast Alaska. Prefer a composite blend coupled with manual adjustments to restore Bering Sea low pressure lost in the blending process due to displacement variances. Opted to increase blend weighting for the GEFS/Canadian/ECMWF ensemble means to maintain maximum product continuity heading into next weekend amid growing system and stream phasing differences in guidance, mainly with respect to a growing signal to lift ample Pacific low energy and moisture up into the western then northern Gulf of Alaska. However, the ECMWF is the least supportive of this system, highlighting lingering uncertainty. ...Weather/Hazards Highlights... A main storm under the influence of an amplified/closed upper trough/low aloft will linger and meander next week over the Bering Sea to enhance winds and waves, with flow periodically wrapping into coastal communities. Guidance is keeping precipitation amounts relatively 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 slowly rising pressures. This could still provide continued inflow into western Alaska. There is also a growing yet still uncertain signal that additional digging and subsequent rounding of ample upstream energies under the base of the main upper trough could act to interact with Pacific system energies set to track underneath to the south. This could result in the lifting of Pacific low energy and rain fueling moisture up into the western to northern Gulf of Alaska by next weekend to monitor. Elsewhere, in advance of this, a weaker lead system tracking across the northeastern Pacific may bring a period of mostly light precipitation to the Panhandle into later next week with a lower confidence due to the forecast spread. 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. Schichtel 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