Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 328 PM EST Sat Feb 25 2023 Valid 00Z Sun Feb 26 2023 - 00Z Tue Feb 28 2023 ...There is a Slight Risk of excessive rainfall over parts of Southern California... ...Heavy snow over the Cascades and Sierra Nevada Mountains... ...Snow and rain/freezing rain over parts of the Upper Midwest... ...There is a Moderate Risk of severe thunderstorms over parts of the Southern Plains on Sunday... A storm over the Great Basin will move eastward to the Ohio Valley/Central Appalachians by Monday evening. The system will create heavy rain/embedded thunderstorms over Southern California, ending overnight Saturday. Therefore, the WPC has issued a Slight Risk of excessive rainfall over parts of Southern California through Sunday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and burn scars the most vulnerable. In addition, the higher elevations of the Sierra Nevada Mountains will have moderate to heavy snow through Sunday morning. There will be a slight pause in the snow on Sunday morning. The threat of excessive rainfall ends by Sunday. The snow will result in reduced visibility and hazardous driving conditions. On Sunday, the snow and lower elevation rain will move into the Southwest and then move into the Central/Southern Rockies by Sunday evening before ending late Sunday night. Meanwhile, onshore flow over the Pacific Northwest will produce rain and higher elevation snow over parts of the Northwest overnight Saturday. A front associated with the moisture will move inland over the Northwest, moving to the Great Lakes by Monday evening. As the front moves inland, snow will move over the Northern Intermountain Region and into Northern California on Sunday morning. By late Sunday morning, rain returns to Central/Southern California as the snow moves into the Northern Rockies. Heavy snow will also return to the Sierra Nevada Mountains continuing into Monday evening. Moreover, upper-level energy will produce snow over parts of the Northeast, ending by Sunday morning. Furthermore, moisture extending from the Southern Plains to the Mid-Atlantic will aid in creating light rain over the region through late Saturday evening. As the Storm over the Great Basin moves out of the Rockies on Sunday afternoon, showers and severe thunderstorms will develop over the Plains. Therefore, the SPC has issued a Moderate Risk of severe thunderstorms over parts of the Southern Plains from Sunday into Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally, there is an increased risk of severe thunderstorm wind gusts of 65 knots or greater over parts of Oklahoma into southwestern Missouri. Overnight Sunday, the rain moves northward into Upper Mississippi Valley/Upper Great Lakes; areas of rain/freezing rain will develop over the region, with the rain/freezing rain moving into parts of the Lower Great Lakes by Monday afternoon. Also, on Monday, the rain will change over to snow over parts of the Upper Mississippi Valley/Upper Great Lakes, and snow developing over parts of the Northeast as rain moves into the Ohio Valley and Mid-Atlantic. In the meantime, showers and severe thunderstorms will develop over parts of the Ohio Valley on Monday. Therefore, the SPC has issued a Slight Risk of severe thunderstorms over parts of the Ohio Valley on Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php