####018003784#### FXAK02 KWNH 212137 PMDAK Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 536 PM EDT Sun Apr 21 2024 Valid 12Z Thu Apr 25 2024 - 12Z Mon Apr 29 2024 ...Overview with Guidance Evaluation and Preferences... 12 UTC GFS/ECMWF/UKMET/Canadian model solutions are well clustered with ensemble means into later this week. This mainly entails meandering a primary low over the Bering Sea and the building of a warming upper ridge over the Interior. A composite solution maintains good detail in this time frame. Guidance solutions remain reasonably well clustered into next weekend, but pattern evolution continuity compared to yesterdayâ€s runs is less than stellar, lowering forecast confidence. The newer runs offer a more rapid transition of Bering Sea upper trough/low energy into the Gulf of Alaska at the expense and uncertainty of the entrainment of Pacific system energies. Prefer to quickly pivot to an ensemble mean blended forecast approach by Saturday in an attempt to mitigate lowering predictability, with a solution that is somewhat less progressive than the models over the Gulf of Alaska. This seems more reasonable considering overall amplitude. Applied manual adjustments to restore maritime low pressure depth lost in the blending process due to displacement variances considering potential support aloft. ...Weather/Hazards Highlights... A main storm under the influence of an amplified/closed upper trough/low aloft will linger and meander into later this week over the southern Bering Sea to enhance winds and waves, with enhanced flow periodically wrapping into coastal communities from the Aleutians to Southwest Alaska. Surface low/front details over the Aleutians/Bering Sea become more uncertain late week, but there is a good signal for the general persistence of cyclonic flow with slowly rising pressures into Thursday/Friday. There was an uncertain signal yesterday 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. However, latest model and ensemble trends instead now steadily progress the main Bering system and wholesale significant height falls bodily and with transition into/across the Gulf of Alaska Friday through the following Monday. This would offer a protracted maritime hazard. This would also focus flow/rainfall from the Alaska Peninsula and Kodiak Island out across South-Central to Southeast Alaska later in this forecast period from mainly the Bering Sea origin system and to a lesser certainty any Pacific based entrainments to still monitor for added moisture availability. 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 north-central mainland, cold high pressure over the Arctic may keep temperatures near to somewhat below normal, especially 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 $$