Rainfall This Week Could Bring Drought Relief and Increased Flood Risk for the Western US [Forecast]

Rainfall is expected to occur in the Western United States this week starting on Tuesday evening, September 13, according to meteorologists.

The Western rainfall is reportedly capable of bringing a drought relief but an increased flood risk for the region.

In recent weeks and months, the West has been ravaged by extreme heat and recurring wildfires, including in the states of California and Washington.

The new weather forecast comes a week after Tropical Storm Kay brought flooding and mudslides in the Southwest, especially in Southern California.

However, local authorities said it did not entirely contribute to the elimination of some ongoing wildland fires due to the persistence of fire weather conditions.

Now, forecasters are saying that further drenching rain is possible for the Western US in the coming days.

The forecast also follows a CNN Weather and National Weather Service (NWS) report regarding a "false fall season" this week, illuminating an extended summer season since June.

The report highlights the relatively cooler temperatures in some parts of the US this week, while the rest of the country will still suffer from hot weather before the official autumn season arrives on September 22.

If the wet weather outlook pushes through, it will likely alleviate the ongoing drought conditions for most parts of the Western US, where wildfire smoke also led to poor air quality.

On average, the U.S. drought monitor reported last week that there are varying levels of dry conditions for Washington, Oregon, California, Idaho, Montana, Wyoming, New Mexico, Colorado, Arizona, Utah, and Nevada.

Western Rainfall Forecast

AccuWeather forecasters said that cooler air with showers and thunderstorms has entered the Western US, several days after record-breaking heat pummeled the region.

In addition, related weather hazards are expected throughout the week.

The adverse weather is caused by a surge of tropical moisture linked with the North American monsoon that has stretched across the Intermountain West.

It caused daily rainfall and storms across the region, as well as strong wind gusts in some locations.

In Phoenix, Arizona, less than an inch of rain arrived on Sunday evening, September 11, wherein damaging wind gusts caused flight delays and diversions at the Sky Harbor International Airport.

NWS Rainfall Forecast

The NWS, through its Weather Prediction Center (WPC), stated that heavy rain and thunderstorms will continue to generate flooding in the Intermountain West and the Four Corners region in the next few days.

The WPC explained that a moisture advection traversing to the Southwest, Great Basin, or Intermountain West will collide with an upper level shortwave energy that will also support widespread precipitation and severe weather.

West Drought Summary

As of September 8, the U.S. Drought Monitor released a report entitled "West Drought Summary" where it mentioned an anomalous upper-level ridge over the central Great Basin over the past week.

The anomaly is reportedly attributed for causing a dangerous heat wave and record-high temperatures across the region.

The record heat also led to the aggravation of fire weather conditions in Northern California, the Pacific Northwest, and the Northern Rockies, the drought agency said.