Extended Forecast Discussion NWS Weather Prediction Center College Park MD 143 AM EDT Sat Aug 04 2018 Valid 12Z Tue Aug 07 2018 - 12Z Sat Aug 11 2018 ...More hot temperatures for the West next week... ...Overview and Guidance/Uncertainty Assessment... The upper high in the west will only begrudgingly abate somewhat by next weekend as an upper low slowly moves into British Columbia. The east will see another trough settle into the region. The models/ensembles were mostly aligned in their forecasts though the 12Z UKMET was slower/deeper than most of the ensembles in the Great Lakes around Wednesday. A deterministic blend was sufficient to start the period. By next Fri/Sat the 12Z/18Z GFS runs were slower to bring in the closed low (weakening to an open wave) and farther south than the ensemble means and 12Z ECMWF/Canadian, but were not the most extreme solution of the multi-center ensemble. Nevertheless, trended toward the ensemble means and ECMWF/Canadian for some details by the end of the period. ...Weather Highlights/Threats... With the upper low lingering offshore, ridging will support well above average temperatures in the West/interior West. Random record highs (including more numerous record warm minimums) are again likely for the Desert Southwest, Great Basin, and interior Northwest (until heights fall and the front pushes ashore). Precipitation should be confined to coastal/northern Washington and then on the east side of the upper high over NM/CO eastward to the southern Plains. Upper trough in the East raises the chance for precipitation that will focus along/ahead of a surface cold front. As it settles into the Southeast, the typical warm/humid airmass will support scattered convection with locally heavy rainfall. Fracasso/Roth WPC medium range 500 mb heights, surface systems, weather grids, quantitative precipitation, winter weather outlook probabilities and heat indexes are found at: https://www.wpc.ncep.noaa.gov/medr/5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/medr/5dayfcst_wbg_conus.gif https://www.wpc.ncep.noaa.gov/5km_grids/5km_gridsbody.html https://www.wpc.ncep.noaa.gov/qpf/day4-7.shtml https://www.wpc.ncep.noaa.gov/wwd/pwpf_d47/pwpf_medr.php?day=4 https://www.wpc.ncep.noaa.gov/heat_index.shtml