The US National Weather Service on Tuesday said the Northern Plains and the Four Corners region were expected to experience fire weather conditions.
Most of the areas across the Southern Plains into the Gulf Coast and the upper Ohio River Valley into the Mid-Atlantic are likely to encounter widespread showers and thunderstorms, with risks of flash flooding.
Widespread rain, gusty winds, and mountain snow are expected in California and the Great Basin due to the presence of a large Pacific storm.
The NWS issued a red flag warning early Wednesday for Montana's Plentywood, Glasgow, Sidney, Circle, Terry, and Glendive. MDU Resources (MDU) unit Montana-Dakota Utilities is among the major service providers in these places.
A similar warning was raised for North Dakota's Williston, Dickinson, and Bowman, which also falls under the service area of Montana-Dakota Utilities.
In Arizona, a red flag warning was raised for Page, Kayenta, Flagstaff, Winslow, Show Low, and areas near Grand Canyon Village, Chinle, and St Johns, primarily served by Pinnacle West Capital (PNW) subsidiary Arizona Public Service Company.
Also placed under a red flag warning watch were Utah's Vernal, Green River, Moab, Hanksville, Capitol Reef National Park, Escalante, Zion National Park, and St. George. PacifiCorp's Rocky Mountain Power is the primary service provider in the state.
Affected areas in Colorado included Cortez, Nucla, Pagosa Springs, Durango, and Telluride. Xcel Energy (XEL) and Black Hills unit (BKH) Black Hills Energy are the primary electricity providers in Colorado
In Texas, the NWS issued a flash flood warning for New Braunfels, while a severe thunderstorm warning was raised for Corpus Christi, Rockport, Kingsville, Bay City. Areas near Refugio were placed under a flood warning watch. American Electric Power's (AEP) Texas unit is among the major service providers in these places.
A flood warning was raised for Mississippi's Meridian, Hattiesburg, and Gulfport. The state is primarily served by Entergy (ETR) and Southern Company's (SO) Mississippi units.
The NWS also issued flood warnings for certain areas of Indiana, Washington, Louisiana, and Kentucky.