USDA's Joint Ag Weather Facility says in the Corn Belt, markedly colder air covers the Great Lakes States, but warmth lingers across southern and western sections of the region. "This morning's temperatures dipped below 32°F across much of Michigan and the northern halves of Wisconsin and Minnesota," USDA reports.
In the West, USDA says chilly conditions prevail west of the Rockies, while beneficial rain and snow showers dot the Intermountain region. "Recent storminess has boosted the average water equivalent of the high-elevation Sierra Nevada snow pack to 13 inches, approximately 46% of the late-March normal," USDA explains.
On the Plains, USDA says warm, windy conditions are enhancing the threat of wildfires, especially across western portions of the region. "Today's high temperatures could exceed 90°F as far north as southern South Dakota," USDA adds.
In the South, USDA reports warm weather—in the wake of last week's rainfall—is promoting a rapid pace of fieldwork and crop development. "However, most of Florida's peninsula remains extremely dry," USDA adds.
In its outlook, USDA says the development of an "Omega block"—a relatively stable jet stream flow in the general shape of that Greek letter—will result in record-setting warmth across the nation’s mid-section and somewhat cooler conditions along and near the Atlantic and Pacific Coasts. "Frost and freeze advisories are already in effect for Monday night and Tuesday morning in a broad area that includes the lower Great Lakes region, the middle Ohio Valley, and the northern Mid-Atlantic region," USDA reports. Meanwhile, a developing storm currently over the Intermountain West will drift northeastward, reaching the Great Lakes region by mid-week, according to USDA. "The storm could produce locally severe thunderstorms across the nation’s mid-section and briefly enhance the threat of wildfires on the High Plains," USDA reports. Storm-total precipitation, in the form of rain changing to snow, could locally exceed an inch across the north-central U.S., particularly in North Dakota, USDA reports. "Toward week’s end, a new storm will emerge from the West and develop over the Plains," USDA explains.