Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 320 PM EST Sun Nov 17 2024 Valid 00Z Mon Nov 18 2024 - 00Z Wed Nov 20 2024 ...Heavy snow over parts of the Olympic Peninsula/Cascades and moderate to heavy snow over the Northern Intermountain Region/Northern Rockies... ...There is a Slight Risk of excessive rainfall over parts of the Southern High Plains on Sunday, Central Gulf Coast on Monday, and Central Gulf Coast/Southeast on Tuesday... ...There is a Slight Risk of severe thunderstorms over parts of the Southern High Plains on Sunday and Southern Plains on Monday... A front over the Pacific Northwest into Northern California will move eastward to the Ohio, Middle/Lower Mississippi Valleys, and Southern Plains by Tuesday evening. A second front extending from the Great Lakes to the Southern High Plains will move eastward, and the front s eastern end will dissipate overnight Monday over parts of the Northeast. A wave of low pressure will develop along the western end of the boundary over the Southern Plains overnight Sunday and moves to northeastward to Central Canada by Tuesday evening while the boundary moves to the Great Lakes to the Lower Mississippi Valley. In addition, a second wave of low pressure will be over the Central Gulf Coast on Tuesday. The Northwest front will create coastal rain over parts of the Pacific Northwest into Northern Central California through early Monday. The system will produce heavy snow over the Olympic Peninsula/Cascades through Monday afternoon, followed by moderate to heavy snow on Tuesday. As the front moves eastward, moderate to heavy snow will develop over parts of the Northern Intermountain Region/Northern Rockies overnight Sunday into Monday, then moderate snow over the region on Tuesday. Further, weak onshore flow will aid in producing rain over parts of coastal Northwest and Northern California on Monday into Tuesday. Meanwhile, as the wave of low pressure moves northeastward over the Southern Plains, moisture will stream northward over the area, producing heavy rain. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Southern High Plains through Monday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas the most vulnerable. Moreover, showers and severe thunderstorms will develop along and ahead of the front over the Southern High Plains. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over the Southern High Plains through Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Additionally, there will be an increased threat of severe thunderstorm wind gusts of 65 knots or greater over parts of the Southern Plains. Furthermore, as the front moves eastward, showers and severe thunderstorms will develop along and ahead of the boundary over the parts of the Southern Plains. Therefore, the SPC has issued a Slight Risk (level 2/5) of severe thunderstorms over the Southern Plains from Monday through Tuesday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Also, on Monday, as tropical moisture streams over the Central Gulf Coast, heavy rain will develop over the region. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Central Gulf Coast from Monday through Tuesday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas the most vulnerable. Likewise, as the axis of tropical moisture moves eastward, heavy rain will develop over parts of the Central Gulf Coast and Southeast. Therefore, the WPC has issued a Slight Risk (level 2/4) of excessive rainfall over parts of the Central Gulf Coast and Southeast on Tuesday. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, small streams, and low-lying areas the most vulnerable. Moreover, rain and thunderstorms will develop over parts of the Upper Midwest and Ohio Valley overnight Monday into Tuesday. Ziegenfelder Graphics available at https://www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php