First warning: Flash floods possible on Thursday

GRAND JUNCTION, Colo. (KJCT) – Thursday is a First Alert Weather Day. Heavy rains may cause flooding and flash flooding in parts of Western Colorado and Eastern Utah.

Flood warning begins this evening

A Flood Warning is in effect from midnight Wednesday night through midnight Thursday night for the Uncompahgre Plateau, Lower Dolores River Valley, Paradox Valley, Dallas Divide, La Sal Mountains, Canyonlands and Arches area. Flash flooding due to excessive rainfall is possible. Runoff into rivers, creeks, streams and other flood prone areas also increases the risk of flooding in these areas. This warning includes Glade Park, Nucla, Naturita, Norwood, Blanding, Paradox, Bedrock, Moab, Canyonlands National Park, Colorado National Monument and Ridgway.

Regular showers and storms likely

Occasional showers and thunderstorms will come in waves through Saturday night or early Sunday morning. There will be dry periods between waves. The waves will form over central and southern Utah and move northeastward, emerging from an area of ​​low pressure aloft over the western U.S. Occasional heavy rain may occur. Flash flooding and flooding are possible outside of the flood warning, but the greatest risk is within the warning. Showers and thunderstorms may favor the mountains in the afternoon, and the valleys may be more affected at night and in the morning.

Predicted rainfall amounts

Rainfall amounts will generally range from 1/4 to 5/8 inch in the valleys through Sunday, including around Grand Junction, Delta, Montrose and surrounding areas. Locally, up to 1 inch of rain is possible. In the higher elevations – including the Uncompahgre Plateau, Grand Mesa, San Juan Mountains, Elk Mountains and La Sal Mountains – amounts of 1 to 2 inches are likely. In small areas high on the Grand Mesa and in the La Sal Mountains, more than 3 inches of rain are possible through the weekend.

Our next 24 hours

Tonight will be mostly cloudy. A few showers or thunderstorms are possible, especially on our nearby mountains. Temperatures will cool from 80-85 degrees at 6 p.m. to 85-87 degrees by 8 p.m., then drop to 80-85 degrees by 10 p.m. Rainy areas may be 5-10 degrees cooler. The rest of the night will be cloudy with occasional showers and thunderstorms. Some thunderstorms may be heavy at times. Thunderstorms may also bring frequent lightning. Morning lows will be 19 degrees around Grand Junction, 15 degrees around Montrose, 16 degrees around Delta, and 14 degrees around Cortez. Thursday will be mostly cloudy with occasional showers and heavy thunderstorms. Localized flash flooding is possible. Thunderstorms may bring frequent lightning. Highs will be 29 degrees around Grand Junction, 25 degrees around Montrose, 28 degrees around Delta and 27 degrees in Cortez.

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