Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 637 PM EDT Wed Jun 17 2020 Valid 12Z Sun Jun 21 2020 - 12Z Thu Jun 25 2020 ...Overview and Guidance/Predictability Assessment... Guidance offers a reasonably similar larger scale medium range pattern evolution for next week, but individual models offer less than stellar forecast spread with especially the timing and emphasis of offshore lows days 4-8. The 12 UTC GEFS/ECMWF ensembles are more consistent and better clustered. A blend of these ensembles and 19 UTC National Blend of Models along with the model with the best fit, the 12 UTC ECMWF, seems to produce a good starting point for the Alaskan medium range forecast package valid Sunday-next Thursday. The blend maintains reasonable WPC product continuity, low strengths consistent with favorable upper support and acts to mitigate less predictable smaller scale variances. ...Weather/Threats Highlights... Energy rotating around a persistent Arctic Ocean upper low will force a surface front and some periods of precipitation underneath across the North Slope/Brooks Range. Lingering instability to the south should also favor a pattern with scattered Interior convection. Lead closed low energy should support a deepened low set to lift slowly northward across the central Gulf of Alaska early next week that will slowly weaken over the northern Gulf into next midweek. This low should be a maritime winds/waves hazard and enhanced rainfall potential should increase across the Alaskan southern tier with lead wrapping moisture. A second Pacific low with seemingly favorable upper support may track eastward to the south of the Aleutians behind the main lead low. This should wrap some rainfall into the Aleutians and possibly more in earnest into the Alaskan Peninsula mid-later next week. 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: 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