Extended Forecast Discussion NWS Weather Prediction Center College Park MD 102 AM EDT Mon Jul 22 2019 Valid 12Z Thu Jul 25 2019 - 12Z Mon Jul 29 2019 ...Overview and Guidance/Predictability Assessment... The models continue to show deamplification of the eastern US trough next weekend into early next week, with persistent upper ridging centered across the Four Corners region/Southwest and developing over Florida. Mid level waves and associated surface fronts traverse the northern tier from the Pacific northwest to the upper Great Lakes. The mid week front stalls as it crosses from the Florida Panhandle/northern Peninsula to South Texas. The front decays next weekend. Farther west, shortwave energy should move a cold front across the northern Great Basin/northern Rockies, reaching the northern High Plains by day 3 (Thu) and 4 (Fri). This fronts decays as the parent low pressure departs into central Canada. Additional shortwave energy is expected to reach the Pacific Northwest next weekend and deamplify as it moves inland across the northern Rockies and Plains next Sun and Mon 29 Jul. Deterministic and ensemble solutions showed sufficient consensus during days 3-7 to use a multi-model blend (12Z ECMWF/ECMWF Ensemble mean/18z GFS/18z GFS Ensemble mean/12 Canadian global/12z UKMET). ...Weather Highlights/Threats... The frontal boundary off the Eastern Seaboard into the Gulf of Mexico is expected to focus areas of showers and thunderstorms from the eastern Gulf coast to Florida. The shortwave/frontal system moving from the Pacific Northwest to the Northern Plains/Upper Midwest should bring an increase in shower/storm chances to the Upper Midwest by late week and across the Great Lakes next weekend and Mon 29 Jul. Meanwhile, daily scattered storms will be possible across the central/southern Rockies as some monsoonal moisture manages to spread into the upper ridge. Temperatures across the central and eastern US are expected to gradually moderate back to normal towards the end of the week. Areas of temperatures 5-10 degrees above normal developing from the central Plains to the lower Great Lakes and northeast Sun 28 Jul and Mon 29 Jul as heights/temperatures aloft in the Ensemble Means climb to above normal values. Temperatures cool to slightly below normal values next Sun 28 Jul to Mon 29 Jul in the northern Rockies to high Plains. 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