Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 245 PM EDT Sun Oct 07 2018 Valid 00Z Mon Oct 08 2018 - 00Z Wed Oct 10 2018 ...Widespread heavy to excessive rainfall likely from the Southern/Central Plains into the Upper Mississippi Valley and Upper Great Lakes region... ...Large temperature contrast expected across the nation between the amplifying upper trof over the Southwest...Great Basin and Rockies and the strong mid to upper level ridge centered along the Mid-Atlantic coast.. ...Tropical Storm Michael expected to enter the southern Gulf of Mexico Monday...threatening the Gulf coast by late Tuesday into Wednesday. Heavy rains may begin to affect the Florida Keys beginning Sunday night... Widespread heavy to excessive rainfall expected over the next three days across the mid section of the nation from the Southern to Central Plains into the Upper Mississippi Valley and Upper Great Lakes region. The slow moving...amplifying mid to upper level trof over the Southwest/Great Basin/Southern Rockies region will continue to provide strong large scale lift in the axis of much above average moisture values that will persist across the Southern to Central Plains into the Upper Mississippi Valley/Upper Lakes region. A series of waves of heavy to potentially excessive precipitation is expected to push in a general south to north direction across the above listed areas over the next several days. This has lead to flash flood watches being issued across a large portion of the Southern to Central Plains and over portions of the Southwest. While the heaviest precipitation amounts are expected to be in the form of rain across the mid section of the nation...there is potential for heavy snows from the Wasatch of Utah..into the Rockies of Colorado/Wyoming Sunday night into Monday and northeast into the Northern High Plains Monday night into Tuesday. There will continue to be large temperature contrasts across the nation over the next few days given the overall very amplified flow from the deep Southwest/Great Basin/Southern Rockies upper trof and the Mid-Atlantic coast upper ridge. High temperatures are expected to be 15 to 25 degrees below average over portions of the Northern to Central Plains...Great Basin and Southwest. At the same time...high temperatures are expected to be 15 to 20+ degrees above average from the Ohio Valley...Lower Great Lakes into portions of the Northeast. Tropical Storm Michael is expected to move slowly northward late this weekend off the east coast of the Yucatan Peninsula and enter the southern Gulf of Mexico on Monday. The initial effects from this system for the U.S. will be across the Florida Keys where heavy rains in some of the outer bands may begin to affect this region late Sunday into Monday. Please refer to the NHC advisories for potential impacts from this system on the Gulf coastal regions later this week. Oravec Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php