Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 333 AM EST Sat Feb 24 2018 Valid 12Z Sat Feb 24 2018 - 12Z Mon Feb 26 2018 ...There is a slight risk of severe thunderstorms over parts of the Lower Mississippi Valley into the Tennessee/Southwestern Ohio Valleys... ...Heavy snow over the Cascades and Northern Rockies... ...Heavy snow for Upper Mississippi Valley/Upper Great Lakes... ...Rain/freezing rain possible over parts of New England... A wave of low pressure over the Southern High Plains will deepen rapidly while moving to the Upper Great Lakes by Sunday morning and continue to move to James Bay by Sunday evening. The system will produce snow over parts of the Southern/Central Rockies into the Central Plains that will move northeastward into the Upper Midwest by Saturday evening. Buy Sunday evening the snow will move out of the Upper Great Lakes into Canada. The snow will be heavy at times over the Upper Mississippi Valley into the Upper Great Lakes overnight Saturday into Sunday. Additionally, showers and thunderstorms will develop along and ahead of the associated front over parts of the Southern Plains into the Lower/Middle Mississippi Valley into parts of the Ohio Valley by Saturday evening. The showers and thunderstorms will move eastward to the Southern Mid-Atlantic/Southeast by Sunday evening, while continuing over the Western/Central Gulf Coast. In addition, rain will develop over parts of the Northern/Eastern Ohio Valley into the Central Appalachian on Saturday morning moving into the Mid-Atlantic by Saturday evening with a few embedded thunderstorms. The rain will move into parts of the Northeast by Sunday morning continuing into Sunday evening. Snow will also develop over parts of Northern New England on Sunday. Areas of rain/freezing rain will develop over parts of interior Northern New England on Sunday, too. Meanwhile, one area of upper-level energy followed by a second will move over the Pacific Northwest moving southeastward to the Central/Southern Plains by Sunday evening. With the addition of onshore flow, coastal rain and higher elevation snow will develop over the Pacific Northwest into the Northern Rockies through Sunday evening. On Saturday, coastal rain and higher elevation snow will move into parts of Northern California and snow into parts of the Great Basin and Central Rockies by Saturday evening into Sunday. A second surge of coastal rain and higher elevation snow moves into the Northwest on Sunday into Sunday evening. The snow levels will low with this storm on Saturday and Sunday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php