A powerful early-season storm system moving across the Southwest will help to trigger numerous showers and thunderstorms along with the threat of flash flooding heading into the weekend.
The most likely timeframe for heavy rain will be from later Friday night through Saturday night, when some thunderstorms will produce downpours that can drop very heavy amounts of rain in a short period of time.
In addition to the rain, gusty winds of over 40 miles per hour can be expected, especially across higher elevations.
While rainfall amounts will vary because of the scattered nature of the heavier pockets of rain and thunderstorm, the potential will exist for more than 2 inches of rain. This amount of rain is more than what typically falls during the entire month of September in many parts of Arizona and Utah.
The threat for flash flooding will include Phoenix and Salt Lake City, especially on Saturday.
Motorists traveling on interstates 10, 15, 17 and 40 through Arizona and Utah, especially on Saturday, should be prepared for blinding downpours and flooding. Remember that many vehicles can be carried away by only a foot or so of water.
Despite the threat for flash flooding, the rain will beneficial to portions of the Southwest that have been dealing with ongoing drought.
While this system will not help bring much, if any, rainfall to the hardest-hit drought areas in California, some places farther east will received welcomed rainfall. Parts of southern Utah and northern Arizona are battling a long-term severe drought and will benefit from the rain.
The trough helping to spawn this storm has already helped bring much-needed rainfall to portions of northern California. The rain helped firefighters battling large wildfires in that area.
A few showers and thunderstorms will continue into Sunday as the storm moves off to the east. Drier weather will prevail across the Four Corners by Monday and Tuesday.