Fox News Weather Center

El Nino-Fueled October to Feature More Rainfall, Storms for Southwest

Rainfall opportunities this week across the Southwest may be the beginning of more substantial drought relief heading into the winter as an El Niño-fueled weather pattern takes shape in the region.

Impacts from the rainfall middle to late week across the Southwest will generally be hit-or-miss drought relief opportunities; the best chances will perhaps hold off until the weekend.

Benefits from the rainfall should largely outweigh the threat for localized flooding, especially across the more mountainous terrain of the region.

Initially, a few showers and thunderstorms will dot the southern half of California.

The number of showers and thunderstorms will increase on Thursday and move farther inland. Areas from the southern California deserts northward to the Sierras will observe the increase in showers and thunderstorms later this week along with southwest Nevada and Arizona.

Palmdale, Las Vegas and Flagstaff will be among a host of other cities to see some rain later this week with rainfall chances lower for Los Angeles and San Diego.

"A 'bowling ball' of upper-level low pressure will feed off the anomalously warm sea-surface temperatures of the East Pacific, bringing needed rainfall to the Southwest later this week and into the weekend," said AccuWeather Meteorologist Ben Noll.

Counter-clockwise flow around the low pressure system will usher in the moisture necessary for the rainfall.

Toward or into the start of the weekend, most of the shower and thunderstorm activity will be across Arizona and southwest New Mexico while the rain chances diminish across the California. Phoenix and Flagstaff will be included in the wet weather.

The diminished chance for rain in California will be short-lived. A fresh storm moving in off of the Pacific Ocean will increase the moisture once again across California.

In fact, Sunday may feature the most widespread rain and beneficial rain for California, but this chance will have to be monitored as the week continues.

Depending on the exact track of the next system, the renewed rain chances could bring wet weather to San Diego, Los Angeles and San Francisco.

Beneficial rainfall across California and Southwest is expected to become increasingly more common heading into the winter months as El Niño encourages an active rainy season.

A look ahead through the end of October is optimistic for the drought-stricken region.

"A pattern of increased cloud cover and greater chances for rainfall will spring to life in the last week or two of October as an El Niño-dominated weather regime springs to life across the United States," said Noll. "Meaningful rain will stretch from the Southwest into Texas and the southern Plains, and, in some instances, bring the risk for flooding."

An El Niño pattern strengthens the southern branch of the jet stream and creates more stormy conditions across the Southwest. This correlation will continue into the winter.

"There's good news and bad news for California [looking ahead to this winter]," said AccuWeather Expert Long-Range Forecaster Paul Pastelok in AccuWeather's 2015 Winter Forecast.

"The 2015-2016 season may yield triple the amount of snow than that which fell last year in the central and northern mountains," said Pastelok. "This is what fills the reservoirs in the spring and early summer."

However, the wet conditions that will frequent the Southwest this winter will lead to instances of flash flooding and mudslides.