Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 354 PM EDT Mon Oct 03 2016 Valid 00Z Tue Oct 04 2016 - 00Z Thu Oct 06 2016 ...There is a slight risk of severe thunderstorms over parts of the Northern/Central Plains and High Plains... ...Heavy rain possible over parts of the Upper/Middle Mississippi Valley... ...Heavy rain possible over parts of the Cascades... ...Temperatures will become 10 to 15 degrees below average over most of the Western third of the U. S.... A deep upper-level low over the Northern/Central Rockies will move northeastward and deepen over the Northern Plains by Wednesday. The system will produce showers and thunderstorms from parts of the Northern High Plains into the Northern/Central Plains southward into the Southern High Plains that will move into the Mississippi Valley by Wednesday. Rain will also develop over parts Northern/Central Rockies and into parts of the Great Basin continuing into Wednesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php