We all know that it has been a hot, dry summer for the state of Utah and for our region. However, our weather is about ready to change as the first true monsoonal push of precipitation arrives this week for northern Utah while the south has seen a few monsoon related storms. This should allow for areas that have not received much precipitation this summer to get a welcomed shot of rainfall and thunderstorms.
What is the monsoon?
It is a change to our seasonal weather pattern with an increase in rainfall activity to areas that are primarily dry during the summer months. In North America, this is called the “North American Monsoon” and occurs during the month of July after a typically dry June across the desert southwest. Seasonal reversal of wind directions leading to temperature differences between land and water also plays a role in the monsoon. This mainly happens in Asia, but North America also sees this activity to a lesser extent.
Tropical moisture is pulled into the southwest United States, thanks to an area of low pressure that tends to sit stationary near Las Vegas while an area of high pressure sits nearly stationary around the Four Corners region. Moisture from the Gulf of Mexico is then pulled into the desert southwest which, when combined with the daytime heating, creates plenty of instability leading to large and juicy thunderstorms.
These severe storms can drop 1 to 2 inches a rain an hour. These larger storms can also sit stationary over dry washes and slot canyons leading to flash flooding throughout southern Utah. Burn scars are also susceptible to debris flows from past wildfires and this can have an effect throughout the state.
We can expect a potential for moderate to high flash flood concerns beginning Wednesday through Friday so be sure to know before you go and pay attention to any warnings that are issued for possible imminent flash flooding over the coming days.
You can check here for flash flood warnings or advisories.