Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 659 PM EST Wed Nov 23 2022 Valid 12Z Sun Nov 27 2022 - 12Z Thu Dec 1 2022 ...General Overview... The start of the extended forecast period on Sunday will be featured with an upper level ridge across the eastern Aleutians and the southwestern mainland, and the low near the southeast Panhandle will be weakening and moving away. However, a second low pressure system is progged to reach the Panhandle region on Tuesday with heavy precipitation and gusty winds. Meanwhile, arctic high pressure governs the overall weather pattern across much of the Interior going into the early-middle part of next week. ...Guidance/Predictability Assessment and Preferences... The 12Z model guidance suite, along with the 18Z GFS, indicates the low over the southern portion of the southeast Panhandle steadily weakening, and also agree well on the upper ridge over the western Gulf region. Shortwave energy from the Bering then breaks through the ridge and forms a new low over the northern Gulf early next week, with the ECMWF indicating a stronger storm compared to the GFS that is in a similar location. The CMC differs here by being a bit farther offshore with the low and is also more progressive as the low tracks southeastward along the British Columbia coast. Model differences become substantial by Wednesday/Thursday across much of the North Pacific and forecast confidence falls to below average. The WPC fronts/pressures forecast was primarily derived from a multi-deterministic blend for Sunday and Monday, followed by an increase of the EC/GEFS means through the middle of the week with about 70% ensemble means by Wednesday-Thursday. ...Weather/Hazards Highlights... For the weekend, the southeast Panhandle will likely get some heavy coastal rain and inland/mountain snow, from a combination of lingering moisture from a weakening short-range storm and the upstream low expected to be offshore by Saturday. Passage of a cold front progressing southward over the mainland behind the Friday-Saturday system may lead to a period of strong gap winds over some areas in the southern coastal areas. The next system in the series will likely produce a broad area of precipitation across the Bering Sea/Aleutians during the weekend, with some of this moisture likely to reach the southwestern half of the mainland by Sunday. Confidence remains limited on the details of precipitation coverage and intensity at this time due to uncertainty on the position and track of a surface low. How much moisture reaches the Panhandle on Monday will be dependent on the exact track of low pressure emerging over the Gulf. There will likely be another frontal system over the Aleutians/Bering Sea early next week and some of the precipitation could reach the far western mainland. The gradient between the front and high pressure departing into northwestern Canada may lead to some brisk winds, but again with low confidence in specifics at this time. High pressure building across the North Slope during the weekend should lead to a colder trend over most of the state from Friday through Sunday, with central areas most likely to see the greatest below normal anomalies. Then the eastward shift and amplification of upper features should bring a warming trend to above normal temperatures over western areas for early next week. Hamrick 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