Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 719 PM EDT Wed May 25 2022 Valid 12Z Sun May 29 2022 - 12Z Thu Jun 02 2022 ...Overview... Upper ridging centered over Mainland Alaska looks to remain in place through at least the middle of next week. This will separate an upper low well north of Alaska (which may send some troughing into the North Slope region) from a train of upper level/surface lows in the North Pacific and keep much of the interior mostly dry and very warm. Models suggest one fairly strong low should lift into the Gulf around next Tuesday-Wednesday with coastal and maritime rain/wind threats. Meanwhile, a weak upper low will drop southward through the far western Aleutians Sun-Mon as it weakens in favor of another low moving eastward well south of the Aleutians. ...Guidance/Predictability Assessment... With the exception of some fairly minor timing/placement differences of systems, the latest model guidance remains in generally good agreement through at least the first half of the period and a general model blend between the 12z deterministic models was preferred. Beyond Monday, some uncertainty lingers regarding the closed low in the Gulf. The 12z GFS was much quicker to break down the upper ridge over the Mainland and weaken/pull north the low, while the ECMWF and CMC suggested more ridging and thus holding the low back in the Gulf. The ensemble means seem to support the idea of stronger ridging over interior Alaska and thus the WPC forecast trended towards the ensemble means/ECMWF for the latter periods. The 18z GFS (available after forecast generation time) did come more in line with the ECMWF and CMC increasing confidence in the WPC forecast. Elsewhere, there remains some question on interactions between the far western Aleutians upper low and the next one moving in south of the Aleutians, but a blend of the ensemble means here (with deterministic model contributions for system definition) seemed to work well. ...Weather and Hazard Highlights... Precipitation across most of Mainland Alaska should be generally very light, and tending to focus along/near a frontal boundary across the northern portion of the state this weekend. By early next week, some increasing precipitation chances could move in towards the eastern Aleutians/Southern Coast/Panhandle with maritime wind threats as well associated with the surface low in the Gulf. Much of interior Alaska will be quite warm with daytime highs averaging near 20 degrees above normal for some areas and fire weather a possible concern in the drier locations. Initial troughing may bring temperatures below normal across the North Slope region this weekend but moderate back towards normal as the upper ridge edges into the region by next week. Far southern locations will be near or below normal influenced by the low in the Gulf. Santorelli No significant hazards are expected over Alaska during this forecast period. 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