Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 535 PM EDT Fri Oct 16 2020 Valid 12Z Tue Oct 20 2020 - 12Z Sat Oct 24 2020 ...Guidance/Predictability Assessment... Upper ridging is forecast to move into western coastal Alaska from the Bering Sea by midweek next week, blocking much of the Interior from significant precipitation. The 12Z guidance showed good agreement overall to start the period Tue-Wed and a deterministic blend sufficed. Thereafter, the 12Z GFS strayed from the 12Z ECMWF/Canadian/UKMET and ensemble mean consensus with its its handling of a northern central Pacific system next week--remaining farther south with its sfc low rather than near the western Aleutians Wed-Thu. Thereafter, the GFS came back into agreement with the ECMWF and ensembles as it takes the surface low eastward just south of the Aleutians with a lead system weakening and flattening in the southern Gulf. With generally good agreement to next Sat, split the difference evenly between the GFS/ECMWF and their ensemble means. ...Weather/Threats Highlights.. Upper ridging will bring above normal temperatures to much of the Interior, especially over the North Slope, with dry conditions. Temperatures may be 10-15 degrees above normal along and north of the Brooks Range, and 5-10 degrees above normal north of the Alaska Range. Areas of eastern/southeastern Alaska and especially the Panhandle will see near to below normal temperatures as high pressure delivers easterly flow to the region. Rainfall will be confined to the Aleutians and coastal Southcentral areas, as well as into the Panhandle as lingering surface low pressure weakens Tue-Wed. It will be rather breezy over the southern Bering due to the tightening pressure gradient between mainland high pressure (nearing 1040mb) and low pressure near the western Aleutians (perhaps 980s or even lower). Fracasso 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