Extended Forecast Discussion NWS Weather Prediction Center College Park MD 105 AM EDT Wed Jul 24 2019 Valid 12Z Sat Jul 27 2019 - 12Z Wed Jul 31 2019 ...Weather Highlights/Threats and Guidance/Predictability Assessment... Latest models still indicate that eastern US upper troughing will gradually deamplify this weekend into early next week as a mid level ridge builds across Florida. A weakening front in Florida and into the Gulf of Mexico will remain a main focus for heavier convection and rainfall, with return warm/moist advection early next week allowing activity to move north across the lower to mid MS Valley and TN Valley and then into the Appalachians Wed 31 July. A persistent feature in the upcoming pattern will be a closed high over the Southwest. Expect daily scattered monsoonal convection will work around the ridge over the southern Great Basin/Rockies/High Plains in upper diffluent flow, and pockets of above normal temperatures in the interior CA/OR and across NV/ID/AZ. Mid-level impulses and wavy surface fronts will traverse the northern tier states from the Pacific Northwest eastward to the Great Lakes and eventually the northeast. These will enhance moisture, instability and showers/storms from the n-central U.S. into the Midwest/Great Lakes. Teleconnections from the Southwest ridge corresponds to a trough from the Great Lakes to the lower OH Valley, where rainfall probabilities increase from early to middle portions of next week. The 12-18Z GFS forecast this trough further east than the GEFS Mean/ECMWF Mean/operational ECMWF. Given the non-GFS solution correspond better with teleconnections next week, the preferred blend did not include the 12-18z GFS. The WPC medium range product suite was mainly derived from a blend of the 12-00 UTC ECMWF/18 UTC GEFS/12 UTC ECMWF ensemble mean. This maintains good WPC continuity. The inclusion of the older 00z ECMWF helped mitigate the faster 12z ECMWF run in moving the northeast Pacific trough onshore and inland faster than the model/ensemble majority Wed 31 July. Petersen 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