Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 427 PM EDT Wed Jun 26 2019 Valid 12Z Sun Jun 30 2019 - 12Z Thu Jul 04 2019 The WPC Alaskan medium range product suite was primarily derived from a composite blend of the 12 UTC GFS/GEFS and 00 UTC ECMWF/ECMWF Ensemble mean guidance along with the 12 UTC National Blend of Models. Model and ensemble forecast spread has decreased since yesterday, bolstering forecast confidence to above normal levels days 4-8. This maintains excellent WPC continuity. Model guidance continues to agree that the northern extent of the upper ridge over the Interior/North Slope will breakdown through the medium range period, allowing for portions of the mainland to be influenced by a stronger and more active westerly mid/upper-level flow. There is a decent guidance signal for a series of weakening frontal systems across the Aleutians and into western portions of the mainland; whose associated shortwaves knock down the ridge, with associated moisture and precipitation working into a lead summertime airmass. A deeper second main system brews back across the Aleutians and Bering Sea before reaching the mainland in about a week with stronger flow. This may also offer a maritime and eventual precipitation/wind threat. Schichtel Additional 3-7 Day Hazard information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php Hazards: - Excessive heat risk across portions of Mainland Alaska, Sat-Sun, Jun 29-Jun 30. - Enhanced wildfire risk across portions of Mainland Alaska, Sat-Wed, Jun 29-Jul 3 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