Fox News Weather Center

Surge of tropical moisture to raise flood threat across southwestern US

A surge of moisture from former-Tropical Storm Javier will help fuel drenching downpours across the southwestern United States into Thursday, elevating the risk of flash flooding.

While Javier is no longer an organized system, a plume of moisture will move northward.

"Moisture from what was once Javier will be drawn through Mexico into eastern Arizona and western New Mexico," AccuWeather Meteorologist Alyson Hoegg said.

The surge will enhance typical summertime monsoonal moisture that is already in place. This will lead to numerous drenching showers and thunderstorms across the region.

Any thunderstorm will be capable of dropping large amounts of rain in a short time. Some could produce rainfall at a rate of 2 to 3 inches per hour.

"These thunderstorms will produce locally heavy rain and flash flooding," Hoegg said.

Travel delays may arise quickly due to flash flooding and road closures. Motorists traveling through the Southwest may face blinding downpours and should allow for delays.

Drivers on interstates 10, 25 and 40 could face delays or slow travel.

Dry stream beds and drainage areas could quickly turn into raging rivers.

While most of these storms will remain below severe criteria, isolated strong wind gusts will still be possible. Any wind gust that does occur could bring down small trees and kick up enough dust to lower visibility.

In addition to drenching downpours, the added moisture from Javier will keep humidity levels high, resulting in uncomfortable conditions outside.

Dew points, a measure of moisture in the air, will be in the upper 60s to lower 70s, a range that is often described as uncomfortable to oppressive.

The most widespread flood threat from storms will last into Thursday, before the moisture will be suppressed southward.

"Thunderstorms will again develop Thursday and Friday afternoon and continue into the evening but outside of locally heavy rain, the flooding threat will greatly diminish," Hoegg said.

The elevated moisture will shift eastward into Texas heading into the weekend and could yield thunderstorms across that region.