Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 335 PM EDT Wed Mar 27 2019 Valid 12Z Sun Mar 31 2019 - 12Z Thu Apr 04 2019 There remains very good agreement in models and ensembles for a strong ridge/upper high building over the mainland through the weekend and into next week which would keep temperatures above average for this time of the year, with a handful of daily record highs possible. There is some question towards the end of the period on if/how much undercutting of the ridge happens which could bring in southerly flow and an increase in precipitation chances by the end of the period to parts of the Peninsula and Southern Coast. The predominant storm track through the period will be through a region of persistent negative 500 hPa height anomalies well south of mainland Alaska, and mostly south of the Aleutians. Some recent model runs have shown potential for a deep low to enter the western Bering Sea by early next week, but solutions have shown high run-to-run variability and thus confidence is low in this specific scenario. An upper ridge across Alaska in a more weakened state would likely be needed to allow a stronger system to enter the Bering, and right now the general consensus is to keep a strong ridge in place through early next week, with perhaps even a slight westward modulation in position. Model consensus was sufficient during the first half of the extended period to base the forecast on a multi-model deterministic blend (ECMWF/GFS/CMC) during days 4-6 (Sun-Tue). After that time, increasing weight was placed toward the ECENS and NAEFS ensemble means to account for increasing uncertainty and spread during days 7-8 (Wed-Thu). Ryan Bullet points from the WPC Days 3-7 Hazards chart can be found at: https://www.wpc.ncep.noaa.gov/threats/threats.php -No significant hazards are expected over Alaska during this forecast period 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