Extended Forecast Discussion NWS Weather Prediction Center College Park MD 104 AM EDT Mon Aug 17 2020 Valid 12Z Thu Aug 20 2020 - 12Z Mon Aug 24 2020 ...Remaining hot for much of the West into next week... ...Overview and Weather/Hazard Highlights... Strong upper ridging over the Southwest will persist into next week as troughing lingers over the lower Ohio, Tennessee, and lower Mississippi River Valleys. This will result in well above normal temperatures in areas west of the Rockies, some of which may approach and exceed record values throughout the Great Basin southward to the Colorado River Valley/Southwest especially through this week. Some isolated showers/storms will dot the landscape over the Rockies each day. A stalled frontal boundary near the Gulf Coast and through the Southeast will be a focus for periods of showers and thunderstorms, especially across Florida. To the north, lighter rainfall is forecast across the Upper Midwest/Great Lakes later this week into the weekend along another frontal boundary. This may push into the Northeast late in the weekend into next Monday. Cooler than normal temperatures will be prevalent over the southeast quarter of the CONUS by only a few degrees. ...Guidance/Predictability Assessment... The latest deterministic guidance was primarily used for the WPC blend for days 3-5, anchored by the 12Z ECMWF and 12Z/18Z GFS which offered the best agreement and consistency from the previous forecast cycle. Canadian/UKMET were close with most features but still differed with the handling of low pressure through southern Canada later this week and over the northeastern Pacific this weekend. 12Z GFS fell out of favor CONUS-wide by about Sunday per its likely too aggressive solution with Canadian troughing. Trended to a nearly even blend of the 18Z GFS/GEFS and 12Z ECMWF/ECMWF ensemble mean for the last two days of the forecast which maintain the western upper high. Fracasso Additional 3-7 Day Hazards information can be found on the WPC medium range hazards chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range 500mb heights, surface systems, weather grids, quantitative precipitation, winter weather outlook probabilities and heat indices are 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