Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 722 PM EDT Sat Apr 15 2023 Valid 12Z Wed Apr 19 2023 - 12Z Sun Apr 23 2023 ...Cold pattern for much of Alaska to temperarily ease next week... ...Guidance Evaluation/Predictability Assessment... Latest models and ensembles now offer more similar larger scale pattern evolutions next week, bolstering foreacast confidence to near normal levels overall, but still differ with the focus of small-mid scale embedded systems over time. A composite of generally compatible guidance from the 12 UTC GFS/ECMWF/UKMET/CMC seems to offer a good forecast basis Wednesday into Friday and the blend process tends to mitigate embedded system differences consistent with uncertainty. This solution also has good ensemble support during this period. Prefer to change guidance preference away from the increasingly varied system depictions of the models toward the more run to run stable and compatible 12 UTC GEFS/ECMWF ensemble means later Friday through next weekend, but kept some model input for better definition. Model timing varies, but in particular they have trended toward a more amplified renewed mainland upper trough versus more modest ensemble mean development. While plausible, prefer to see a few more model cycles to confirm. ...Overview and Weather/Hazard Highlights... Upper lows/troughs over the Arctic Ocean, through the mainland and additionally over the Gulf of Alaska are expected to remain roughly sandwiched between upper ridges centered both to the west and east of Alaska, allowing a a blocky pattern to linger into early-mid next week. The pattern is slated to become transitional mid-later next week as ridging to the west of the state reforms into a strong closed high to center near the Bering Strait. Height rises downstream over the mainland may be limited in this transition, but should allow some temporary easing of the cold pattern. However, expect cold conditions of varying degrees may prove hard to fully dislodge for much of the state. There is now a growing signal for a renewed cooling upper trough to dig southward down through the mainland Friday-next weekend. The North Slope/Interior then South-central would accordingly become more unsetlled with scattered light snows. Farther south, there is a risk of deeper than expected Gulf of Alaska low developments to monitor given potentially potent, but quite uncertain energy interactions within a mean upper trough position held over the area. Periods of light to locally moderate precipitation will mainly be limited to Southeast Alaska. There is potential there for enhancement heading into next weekend if any of the uncertain Gulf of Alaska lows develop and track with close enough proximity. 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