Extended Forecast Discussion NWS Weather Prediction Center College Park MD 245 AM EDT Sun May 19 2019 Valid 12Z Wed May 22 2019 - 12Z Sun May 26 2019 ...Overall Weather Pattern... The upper level pattern across the continental U.S. will remain quite amplified and slow to change next week. A hot upper level ridge over the southeast U.S. becomes anchored over the region and gradually becomes stronger for the second half of the upcoming work week. Across the western U.S., a large scale upper trough will be dominant as multiple shortwave perturbations keep conditions cool and unsettled. This will also be slow to move given the expected development of an omega block type pattern upstream over the eastern Pacific. Lead main weather features include a strong low pressure system for the Plains and Upper Midwest Tue/Wed, followed by weaker lows and frontal boundary meanderings from the Southwest to the Northeast U.S. later week overtop the Southeast ridge. The pattern offers a periodic local threat for strong to severe convection and potential for cell training/excessive rainfall. ...Weather Highlights and Hazards... The main things that will make weather headlines for the second half of the week and extending into next weekend will be the anomalous heat and humidity building across the southeastern quadrant of the nation, the unseasonably cool weather expected for the interior western U.S. and northern plains, and the ongoing threat of heavy rainfall and potential severe weather across the central U.S. High temperatures are forecast to be on the order of 10 to 15 degrees above late May averages from the Midwest to the Southeast U.S., with the hottest readings expected for the Friday to Sunday time period. There is a good chance that the first 100 degree temperatures of the season could be realized across inland portions of southern Georgia and South Carolina. The opposite will hold true for the western U.S. under the influence of the upper level trough, with daytime highs of 15 to 25 degrees below normal for mid-week, and then moderating to 5 to 15 degrees below normal by the end of the forecast period. D. Hamrick 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