There is a powerful early-season storm that is tracking across the Southwest, and this will help trigger many showers and thunderstorms along with the threat of flash flooding as we head into this weekend. As for the time frame with this system, the most likely chance for heavy rain and flash flooding will occur from later on Friday night into Saturday and Saturday night.
Some of these storms are capable of producing downpours that can drop very heavy amounts of rain in a short period of time. In addition to the rain and flash flood threat, strong winds of over 40 mph can be expected in the area, especially in areas of higher elevations. Essentially, the mountainous regions will have the highest threat for gusty winds.
The rainfall amounts will surely vary because this system is very scattered. There will be heavier pockets of rain with this particular system, and the potential will exist for more than 2 inches of rain in a short time span. Now, this amount of rain is definitely more than what typically falls during the entire month of September in many parts of the desert regions of Arizona and Utah.
Now, the threat for flash flooding will include Phoenix and Salt Lake City, especially on Saturday. If you are a motorist and plan on traveling on Interstates 10, 15, 17 or 40 throughout Arizona and Utah, you should definitely be prepared to deal with blinding downpours and flooding disasters.
This will most likely occur mid-day Saturday. It is always important to remember that many vehicles can be carried away by water, and it only takes a little over a foot of water to do this. Now despite the threat for extensive flash flooding, the rain will definitely be beneficial to parts of the Southwest that have been dealing with extreme and ongoing drought for a while.
Even though this system probably won’t bring much help, if any, rainfall to the hardest-hit drought areas in California, some places in the farther east will receive very welcomed rainfall. Parts of Southern Utah and Northern Arizona are still facing a long-term severe drought and will benefit from the rain very much.
The trough that is helping to spawn this storm has already helped greatly, bringing much needed rainfall to portions of northern California that has been drought stricken since early last year. The rain also helped against battling the large King wildfires in that area, that firefighters have been trying profusely to put out.