Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 352 AM EDT Mon Sep 30 2019 Valid 12Z Mon Sep 30 2019 - 12Z Wed Oct 02 2019 ...There is a moderate risk of excessive rainfall over parts of the Southern High Plains/Southern Rockies with a slight risk of excessive rainfall over parts of the Middle Missouri Valley... ...The major winter storm across the Northern Rockies will wind down... ...Much below average temperatures across the Northwest into the Northern High Plains, and much above average temperatures east of the Rockies/Northern Plains... A deep upper-level low over the Northwest will slowly weaken and start to move eastward by overnight Tuesday. A front extending from the Northern Plains southwestward to the Central High Plains into parts of the Great Basin will move eastward to the Great Lakes/Ohio Valley southwestward to the Central High Plains by Wednesday. Moisture from the Western Gulf of Mexico will stream northward over the Southern Plains into the Upper Midwest. In addition, the Gulf moisture will flow westward banking up against the Southern Rockies. Showers and thunderstorms will develop east of the Southern Rockies into the Middle Mississippi Valley. Furthermore, tropical moisture (in part from Tropical Storm Narda in the East Pacific at upper-levels) will funnel into the Central U.S.. Heavy rain associated with the showers and thunderstorms will produce conditions where numerous flash flooding is likely, with many streams that may flood potentially affecting larger rivers over parts of the Southern High Plains/Southern Rockies through Tuesday morning. Also, scattered flash flooding is possible in mainly localized areas over parts of the Middle Missouri Valley, likewise, through to Tuesday morning. The showers and thunderstorms will continue to develop along and ahead of the boundary over parts of the Middle Mississippi Valley to the Southern High Plains through Wednesday. Heavy rain will also be associated with these storms. A large temperature range is expected across the CONUS into Wednesday as an upper-level troughing dominates in the West, and upper-level ridging builds across the East. Underneath the trough, daytime highs could be 20 to 30+ degrees below average across much of the Northwest with several daily record low maximum temperature records possible into Tuesday, especially across the Northern Great Basin/Rockies and California. Meanwhile east of the Rockies, temperatures will be much above average. The core of the heat will be from the Southeast/Central Gulf Coast States to the Ohio Valley where widespread daytime highs in the mid to upper 80s near 90 (north) and mid to upper 90s (south) could approach or exceed record values. For the East, this stretch of record warmth will continue through much of the week. Additionally, warm, dry, and gusty weather across Colorado will continue the critical fire weather conditions through Monday where red flag warnings are currently in effect. The ongoing major winter storm across the Northern Rockies is expected to wind down on Monday. An additional 1 to 2 feet (locally higher) of snow is still possible, particularly for portions of Western Montana. Winter storm warnings and advisories remain in effect for much of the North-Central Montana through Monday morning. Strong winds may bring blizzard conditions, with blowing snow continuing to disrupt travel on Monday even after the snowfall has come to an end. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php