A front extending from the Northeast to the Southern Plains will move off most of the Eastern Seaboard by Tuesday evening.
Article continues below
Moisture from the Gulf of Mexico will stream northward over the Western Gulf Coast/Lower Mississippi Valley into the Ohio Valley.
The moisture will produce showers and strong to severe thunderstorms with heavy rain over parts of the Western/Central Gulf Coast and the Southeast.
Therefore, the WPC has issued a Slight Risk of excessive rainfall with these thunderstorms over parts of the Western/Central Gulf Coast and the Southeast through Monday morning.
The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable.
Furthermore, some of the thunderstorms will be strong to severe.
Therefore, the SPC has issued a Marginal Risk of severe thunderstorms over parts of the Western/Central Gulf Coast and part of the Southeast from Sunday into Monday morning.
The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes.
The threat of excessive rainfall and severe thunderstorms ends on Monday.
Additionally, lake-effect snow will develop downwind from the Great Lakes and snow over parts of the Northeast.
Rain will develop over parts of the Lower Mississippi, Tennessee, and Ohio Valleys, along with parts of the Northeast and the Mid-Atlantic/Southeast Sunday evening into Monday.
Along the rain/snow line, light rain/freezing rain areas will develop from the Southern Plains into the Ohio Valley from Sunday evening to Monday evening.
On Monday, lake-effect snow will continue downwind from the Great Lakes and upslope snow over parts of the Central Appalachians and snow over parts of the Northeast.
The snow will result in reduced visibility and the snow/ice will produce hazardous driving conditions.
Meanwhile, cold high pressure over the Northern Plains will move southward to the Ohio Valley by Monday.
The cold air will bring temperatures 15 to 35 degrees below average over parts of the Northern Rockies/Great Basin to the Plains and Upper Mississippi Valley.
As the cold air moves southward, the intensity of rain/freezing rain will pick up over parts of the Southern Plains and a greater area of rain/freezing rain from parts of the Lower Mississippi Valley into the Ohio Valley from Monday evening into Tuesday evening.
Moreover, an upper-level low will develop over Northern California on Sunday, move southward to Southern California and Northwestern Mexico by Monday evening, and weaken slightly on Tuesday.
A front associated with the energy will also move southward from the Great Basin/California to the Southwest/Southern Rockies by Tuesday evening.
The system will produce coastal rain and higher-elevation snow over California on Sunday into Monday morning.
The coastal rain and higher-elevation snow will continue over parts of California on Monday.
Furthermore, snow will develop over parts of the Great Basin/Central Rockies and Central High Plains from Sunday evening into Monday morning.
On Monday, the snow will move into parts of the Southwest.
On Tuesday, the snow will start to wane over the Southwest and Central/Southern Rockies, with rain at lower elevations of the Southwest.
The snow will result in reduced visibility and hazardous driving conditions. ■