Weather across America

(NATIONAL) There is an Enhanced Risk of severe thunderstorms over parts of the Plains and Mississippi Valley, heavy snow coming for the Northern and Central Plains, and a Slight Risk of excessive rainfall over parts of the Southern Plains and Lower Mississippi Valley.

On Sunday, a front over the Southern Plains and Lower Mississippi Valley will move northward as a warm front. Moisture pooling along the boundary will produce heavy rain. Therefore, the Weather Prediction Center (WPC) has issued a Slight Risk of excessive rainfall over parts of the Southern Plains/Lower Mississippi Valley into Monday morning. The associated heavy rain will create mainly localized areas of flash flooding, with urban areas, roads, and small streams the most vulnerable.

West of the warm front, there is a dryline bisecting the Southern Plains where showers and severe thunderstorms will develop. Therefore, the Storm Prediction Center (SPC) has issued an Enhanced Risk of severe thunderstorms over the Southern Plains through Monday morning. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes. Furthermore, there is an increased threat of severe thunderstorm wind gusts of 65 knots or greater, hail of two-inch or greater, and EF2-EF5 tornados over parts of the Southern Plains.

Meanwhile, weak onshore flow and additional upper-level energy will create coastal rain and higher-elevation snow over the Pacific Northwest and Northern California through Monday evening. In addition, the energy will produce heavy snow over the Cascades through Tuesday morning. Snow also develops over the Northern Intermountain Region, continuing into Tuesday evening. On Tuesday, the coastal rain continues over parts of the Pacific Northwest and Northern California.

Additionally, as the low pressure associated with a front moves into the Upper Midwest on Sunday evening, light snow will develop over parts of the Upper Midwest into Monday evening. As the storm moves into Michigan, light rain and snow develop over the Upper Great Lakes from Sunday evening into Monday morning. Furthermore, rain will develop along the front on Monday afternoon into Monday evening from parts of the Northeast to the Ohio Valley, as showers and thunderstorms will return to the Southeast on Monday.

The upper-level energy develops a wave of low pressure along a front over the Great Basin by late Sunday evening. The surface low will move eastward across the Rockies on Monday and into the Central Plains/Middle Mississippi Valley by Tuesday evening. The system will produce snow over the Northern/Central Rockies overnight Sunday into Monday. The system will produce a major winter storm producing over a foot of snow from the Central Rockies to the Northern Plains, challenging some April snow records in the Dakotas and northwest Minnesota. Localized 24 inches plus totals are possible from southeast Wyoming to central South Dakota. Avalanches and significant impacts from snow load are possible across portions of Utah.

Additionally, strong wind and heavy snow will create whiteout conditions Tuesday, causing dangerous to impossible driving conditions and considerable disruption to daily life. Furthermore, wind chills will fall to near or below zero during the blizzard in the Northern Plains, which could be life-threatening to anyone stranded. Widespread gusts in excess of 50 MPH will spread from the Southwest and Four Corners on Monday and into the Plains Tuesday. As a result, power outages, wind damage, and blowing dust, are likely produced outside of thunderstorm activity.

In the meantime, in the warm sector, as the associated front moves onto the Plains, showers and severe thunderstorms will develop over parts of the Plains and Mississippi Valley on Tuesday. Therefore, the SPC has issued an Enhanced Risk of severe thunderstorms over the parts of the Southern Plains, Middle and Lower Mississippi Valley, and the Western Ohio Valley on Tuesday. The hazards associated with these thunderstorms are frequent lightning, severe thunderstorm wind gusts, hail, and a few tornadoes.