Extended Forecast Discussion NWS Weather Prediction Center College Park MD 332 PM EDT Thu Jul 25 2019 Valid 12Z Sun Jul 28 2019 - 12Z Thu Aug 01 2019 ...Weather Highlights/Threats and Guidance/Predictability Assessment... A strong/hot upper high will slowly migrate out of the Southwest and into the southern Rockies next week as a summertime upper ridge builds through the west-central U.S. The Southwest will see an increase in monsoonal-driven showers/storms as the upper high moves to the east of Arizona, allowing Mexican moisture to advect northward and around the upper high across the south-central Great Basin/Rockies. This main ridge/high will be sandwiched by gradually amplifying upper troughs offshore the Northwest and over the eastern U.S. A lead and weakening surface front stalled over Florida and the Gulf of Mexico will boost convective potential into early next week. Surface fronts will also meanwhile traverse the US/Canadian border through this forecast period with area-wide light/modest rainfall, but with a risk of locally heavier amounts with focused convection, especially over and downstream from the Midwest/Great Lakes. Model and ensembles agree fairly well with each other Sun-Tue such that a consensus blend approach served well as a starting point. By next Wed/Thu the 00/06 UTC GFS offer a break from continuity and now bring much more ample Pacific height falls/troughing rapidly inland across Canada. This is not well supported by GEFS/ECMWF ensembles that preferably hold more system energy offshore more in line with the 00 UTC ECMWF and WPC continuity. Schichtel 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 Hazards: - Heavy rain across portions of the Upper Midwest and the Upper Great Lakes, Sun, Jul 28. - Flooding occurring or imminent across portions of the Mississippi and Missouri River Basins. - Excessive heat across portions of California, Sun, Jul 28. 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