Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 423 AM EDT Tue Mar 27 2018 Valid 12Z Tue Mar 27 2018 - 12Z Thu Mar 29 2018 ...There is a slight risk of severe thunderstorms over parts of the Southern Plains... ...Heavy rain possible from parts of the Southern Plains to parts of the Ohio/Tennessee Valleys... ...Heavy snow possible over parts of the Northern Cascades and the Northern Rockies... A front extending from the Southern Plains northeastward to the Great Lakes will become quasi-stationary moving very slowly to the Lower Great Lakes to the Southern Plains/Western Gulf Coast by Wednesday evening. Moisture from the Western Gulf of Mexico will stream northward pooling along the boundary through Wednesday evening. Showers and thunderstorms will develop along and ahead of the front over the Southern Plains and the Lower Mississippi Valley that will expand into the Tennessee Valley overnight Tuesday and into parts of the Southeast/Southern Appalachians by Wednesday evening. Rain, heavy at times, will also develop along the boundary over parts of the Middle Mississippi Valley into parts of the Ohio Valley through Wednesday evening. Rain will also extend into the Great Lakes that will move into parts of the Lower Great Lakes and the Central Appalachians by Tuesday evening. The rain will continue to move into the Northeast by Wednesday morning, ending over the Northeast by Wednesday evening. As the rain moves into the Northeast there will be pockets of rain/freezing rain over the region Tuesday morning into Wednesday morning. In addition on Wednesday, the rain will move into the Northern Mid-Atlantic through Wednesday evening. Furthermore, snow will develop over parts of the Central/Southern Rockies on Tuesday morning ending overnight Tuesday. Meanwhile, onshore flow and upper-level impulses will aid in producing rain and higher elevation snow over parts of the Pacific Northwest that will end by Wednesday morning. Snow will also develop over parts of the Northern Intermountain Region/Northern Rockies on Tuesday expanding into parts of the Central Rockies by Wednesday evening. Additionally, a front moving southward out of West-Central Canada, overnight Tuesday, will move southeastward to the Central Plains and extending into the Upper Great Lakes by Wednesday evening. The system will develop rain over parts of the Northern Plains overnight Tuesday that will mix with snow over parts of the Northern Plains by Wednesday morning. The rain and snow will move into parts of the Upper Mississippi Valley and Upper Great Lakes by Wednesday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php