Monsoon Storms Could Bring Flash Flooding, 58 MPH Winds To Tucson

TUCSON, AZ — Southern Arizona's monsoon is about to kick into high gear.

Forecasters are warning that Monday could bring a dangerous mix of thunderstorms, damaging winds, blowing dust and flash flooding across much of the region, even as an Extreme Heat Warning remains in effect until 8 p.m.

According to the National Weather Service in Tucson, storm coverage will increase through the afternoon and evening as temperatures climb 4 to 7 degrees above normal. While the heat will linger through Monday, a more active monsoon pattern is expected to bring gradual cooling later this week.

Storms are expected to begin developing over the White Mountains and the Sky Islands around midday before spreading into the valleys during the afternoon.

Forecasters say the upper-level weather pattern could allow storms to persist longer than usual, with some capable of producing wind gusts of at least 58 mph, hail up to 1 inch in diameter and areas of blowing dust.

A Blowing Dust Advisory is in effect from 2 to 8 p.m. Monday for areas from Tucson eastward, then from 4 to 10 p.m. across the western deserts as storms move west.

Forecasters say conditions could support the development of a haboob — a massive wall of dust driven by thunderstorm outflow — especially as storms move across Cochise County and pick up dust from dry lake beds such as the Lordsburg Playa in New Mexico and the Willcox Playa.

The flood threat is greatest south of Tucson.

A Flash Flood Watch remains in effect from 2 to 10 p.m. Monday for areas including Nogales, southeastern Pima County and southwestern Cochise County. Rainfall totals of 1 to 3 inches are possible, raising the risk of rapidly flooding roads, normally dry washes, rivers and other low-lying areas.

Forecasters specifically highlighted the Nogales Wash and the Santa Cruz River as waterways that could rise quickly if heavy rain develops.

The active monsoon pattern is expected to continue Tuesday and into the middle of the week. While additional rounds of afternoon and evening thunderstorms remain possible, the increased cloud cover and rainfall should help ease the extreme heat, with temperatures settling to about 3 to 6 degrees above normal through the rest of the week.