Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 321 AM EDT Sat Sep 17 2016 Valid 12Z Sat Sep 17 2016 - 12Z Mon Sep 19 2016 ...Locally heavy rain possible today from the Mississippi valley to the lower Great Lakes... ...Severe thunderstorms possible across the southern High Plains... ...Temperatures will warm across much of the U.S. into early next week... A relatively slow-moving cold front will bring showers and thunderstorms to areas from the lower Mississippi valley to the Great Lakes and Northeast today. Locally heavy rain will be possible in these areas. The front will move east on Sunday, bringing showers and thunderstorms to much of the Mid-Atlantic and Northeast. Farther west, scattered thunderstorms will be possible along the trailing stationary end of the frontal boundary, across the southern and central High Plains today. Some thunderstorms may be severe across the southern High Plains, and the Storm Prediction Centers has outlined portions of this area for a slight risk of severe thunderstorms. Two Pacific cold fronts and upper-level disturbances will bring areas of showers to the northwestern U.S. today into Sunday. The first of these upper-level disturbances will move into the Upper Midwest by Sunday afternoon and evening, bringing scattered showers and thunderstorms. Temperatures will be near or slightly above average across most of the nation today, but should gradually warm through Monday. By Monday, high temperatures are forecast to be 5 to 15 degrees across most of the nation, with the exception of the Pacific Northwest, where clouds and some showers will keep temperatures slightly below average. Ryan Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php