Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 330 PM EDT Mon Oct 08 2018 Valid 00Z Tue Oct 09 2018 - 00Z Thu Oct 11 2018 ...Widespread heavy to excessive rainfall will continue into Wednesday from the Southern Plains to the Great Lakes... ...Hurricane Michael will begin impacting the eastern Gulf Coast by late Tuesday and into Wednesday... ...Large temperature contrast between the Eastern U.S. and the Central/Western states... Widespread heavy to excessive rainfall is expected to continue along a quasi-stationary frontal boundary from the Southern/Central Plains into the Upper Mississippi Valley and Upper Great Lakes tonight and through Tuesday. Flash flooding will remain a threat, especially across portions of Texas and Oklahoma where WPC has a high risk of excessive rainfall through Tuesday morning and a moderate risk from Oklahoma through northern Wisconsin Tuesday into early Wednesday. In addition to the heavy rainfall, severe thunderstorms will be possible within a very moist and unstable airmass, and SPC has highlighted this entire region -- from the southern Plains to the Upper Midwest -- within a slight risk on Tuesday. By Wednesday, the upper level system responsible for this event should finally begin pushing slowly eastward, but heavy to excessive rainfall will still be possible along the front from the lower Mississippi Valley into the Upper Great Lakes. In addition, there is potential for heavy snowfall on the backside of this system across the higher elevations of the Great Basin, Central Rockies, and into parts of the northern High Plains. Hurricane Michael, currently located in the eastern Gulf of Mexico, is forecast to be a dangerous major hurricane by the time it reaches the northeastern Gulf Coast on Wednesday. Moisture associated with Michael has already started to produce showers and thunderstorms across portions of the eastern Gulf Coast, but the bulk of the heavy rainfall is expected to arrive by Tuesday evening as Michael's center nears the coastline. Regardless of the exact track or intensity at landfall, heavy rainfall and life-threatening flash flooding are possible across the Florida Panhandle and Big Bend region on Wednesday, and into portions of the Carolinas by Thursday. In addition, Michael is expected to produce life-threatening storm surge along the Florida Gulf Coast. For the latest information regarding Michael, please refer to the National Hurricane Center at www.hurricanes.gov. With regards to temperatures across the country, the nations midsection will continue to be the dividing line between a strong upper level ridge across the East, and an amplifying upper level trough in the West. Temperatures for portions of the East are forecast to be as much as 10 to 20 degrees above normal, with widespread record high overnight minimum temperatures likely. A handful of afternoon high records are in jeopardy as well, especially across the Ohio Valley and lower Great Lakes on Tuesday. On the other side of the front, temperatures will be well below normal, with afternoon highs of 20 to 30 degrees below normal possible for portions of the Central and Northern High Plains. Santorelli Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php