Lightning lit up the sky over Antelope Island, Utah, on Sunday. For the first half of the week, more storms will move across the western half of the U.S.

Monsoon moisture brought stormy conditions to the Southwest over the weekend, producing an incredible display of lightning over Antelope Island, Utah, which a drone captured. Today, monsoonal moisture will bring more storms to the Southwest.

The WeatherRadar shows the potential for more slow-moving thunderstorms over Arizona, Utah, Colorado and New Mexico. Cities such as Phoenix and Santa Fe, Ariz., could see flash flooding with some of these heavy downpours.

The flood threat for the Southwest will linger into midweek. A few strong storms are also forecast for Montana and the northern Plains on Tuesday and Wednesday. Keep an eye on the WeatherRadar and make sure your Weather & Radar app alerts are turned on.