Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 400 PM EDT Thu Oct 04 2018 Valid 00Z Fri Oct 05 2018 - 00Z Sun Oct 07 2018 ...A flash flood threat exists from eastern Kansas northeastward into the Upper Great Lakes on Friday... ...Potential for severe weather expected over areas of Kansas and the Oklahoma/Texas panhandles... ...Well below average temperatures anticipated across much of the western/central U.S. while vast warmth extends elsewhere... Highly amplified flow across the country will keep a very active weather pattern heading into the weekend. Southwesterly flow aloft over the middle of the country will feature a series of embedded disturbances forecast to race from the Four Corners toward the Upper Midwest. Such impulses are expected to traverse atop a potent frontal boundary and abundant moisture from the Gulf of Mexico. Widespread showers and thunderstorms should extend from west Texas northeastward across much of eastern Kansas and Missouri into the Great Lakes. Within this area of active weather, the primary flash flood threat will exist from the Central Plains northeastward into the Upper Great Lakes, mostly on Friday into Saturday morning. A Moderate Risk for flash flooding is in place over eastern Iowa into northern Illinois/southern Wisconsin given heavy rainfall on top of soils which are saturated from prior hydrologic events. Additionally, the Storm Prediction Center is anticipating an organized threat for severe thunderstorms across sections of Kansas down into the Oklahoma/Texas panhandles. Not to be forgotten, along the northern extent of the precipitation shield, surface temperatures will be cold enough to support snowfall accumulations. Based on the latest forecast, 4 to 6 inches of snow is possible over North Dakota while slightly lighter amounts into northern Minnesota. Farther west, Pacific systems traversing inland will spread modest snow amounts to the Tetons northward into southwestern Montana. A sharp frontal boundary stretching across the nation will support a fairly impressive temperature gradient. North of this meandering front, departures from climatology should be on the order of 15 to 20 degrees primarily over the Northern Rockies into the adjacent Northern/Central Plains. High temperatures should struggle to get out of the upper 30s to lower 40s across the northern tier of the country. While daily records should not be broken, it definitely will feel like Autumn in these locations. On the contrary, south of the boundary, abundant warmth will be commonplace as a vast ridge sits overhead. Readings will likely be 10 to 15 degrees above average favoring widespread 80s and even perhaps 90 degrees as far north as St. Louis, Missouri on Friday. Given the humid conditions, overnight radiational cooling should be limited leading to lows in the mid/upper 60s. This could support some daily records, especially across the mid-South and into the Appalachians. Rubin-Oster Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php