A dangerous weather split grips the country Monday as severe thunderstorms pound the Ohio Valley while record heat scorches the West.  

The Ohio Valley faces its most serious threat as a cold front crashes into warm, humid air. This violent collision may spawn powerful thunderstorms capable of knocking down trees and power lines with wind gusts exceeding 60 mph. Quarter-sized hail could pelt areas from Cincinnati to Charleston, W.Va., where residents should take precautions by securing outdoor furniture and having multiple ways to receive weather alerts. While the tornado threat remains low, any storm could produce brief twisters in the most unstable air. 

While storms rage in the East, lake-effect snow will develop across parts of the northern Midwest Monday night. Traditional snowbelt areas downwind of Lake Superior, including Michigan's Upper Peninsula and northern Wisconsin, could see 1 to 3 inches of wet, heavy snow accumulation. The highest amounts will focus on grassy and elevated surfaces, with roads likely remaining wet rather than snow-covered due to marginal temperatures.  

Further west, a massive high-pressure system continues its unrelenting grip, cooking the region with record-breaking heat. Southern California and Arizona will swelter through afternoon highs in the 90s, with some inland desert locations approaching triple digits. The Pacific Northwest enjoys milder conditions with temperatures in the 50s and 60s, while the Rockies shiver with highs only reaching the 30s and 40s. The highest mountain peaks will retain their winter snowpack even as lower elevations experience early spring conditions. 

The dramatic temperature extremes highlight spring's volatility across the nation. While the Southeast basks in pleasant 70s and the Mid-Atlantic enjoys comfortable 60s, the northern Plains remains stuck in 40s. This sharp contrast demonstrates how jet stream patterns can create vastly different weather conditions from one region to another. 

Residents in affected areas should take appropriate precautions. Those in the storm zone should identify safe shelter locations, while Westerners enduring the heat should stay hydrated and limit afternoon outdoor activities. Travelers in the northern Midwest should prepare for possible slippery spots Monday night as the lake-effect snow develops.