Long-awaited wet weather to arrive in Southwest
By
Jessica Storm, AccuWeather Meteorologist
Updated Oct 4, 2021 8:43 PM EDT
Have you ever wondered what you're breathing into your lungs if you inhaled wildfire smoke? It’s not just the smoke that can drastically impact your health.
Wet and humid weather is on the way to the Southwest this week, which could even produce the first measurable rain at the Los Angeles International Airport since July and cause locally heavy downpours at higher elevations.
Ahead of the rainy shot, hot and dry conditions continued across the region this past weekend, providing high temperatures in the upper 80s in Los Angeles on Sunday, over 10 degrees Fahrenheit above average. Las Vegas had temperatures around 90 F on Sunday, just a few degrees above the typical high temperature of 88 F.
However, cooler and wetter conditions will be rushing into the Southwest within the week. It will be rather unsettled and cloudy across Southern California on Tuesday, according to AccuWeather Senior Meteorologist Mike LeSeney.
A thunderstorm that moved through the Los Angeles area late Monday afternoon caused a delay in the Monday Night Football matchup between the Los Angeles Chargers and the Las Vegas Raiders.
Heavy rainfall from showers and thunderstorms is expected across much of the Southwest, especially in California, Nevada and Arizona. AccuWeather forecasters are predicting a possible thundershower in downtown Los Angeles on Tuesday, though the heaviest precipitation is expected to stay mainly in the mountains.
A dip in the jet stream will develop into a "cut-off" area of low pressure offshore southwest of Southern California this weekend, according to LeSeney.
Low pressure that is "cut off" is also known as a closed area of low pressure in the upper levels of the atmosphere that has become completely displaced from the typical westerly current.
"This upper-level low will then spin its way towards the Southern California coast and will move ashore Monday night," said LeSeney.
Showers and thunderstorms will form generally on Tuesday from Southern California to western New Mexico, moving into the Four Corners region on Wednesday.
"Cold air aloft will be stacked overtop warmer air at the surface resulting in atmospheric instability and the formation of showers and thunderstorms, especially over the higher terrain of the mountains," explained LeSeney.
Heavy thunderstorms can impact places like Flagstaff and Sedona, Arizona, on Tuesday afternoon. Temperatures will also drop drastically on Tuesday, including in Flagstaff, where the high temperature is anticipated to remain at least 10 degrees below average and in the middle 50s. Los Angeles is forecast to have high temperatures in the refreshing middle to lower 70s on Tuesday and Wednesday.
"This storm will also bring in more humid air which may result in locally heavy rainfall, especially during the afternoon and evening hours when showers and thunderstorms may be most numerous," said LeSeney.
Despite most of the Southwest experiencing drought conditions, these heavier storms bring the chance of flooding, especially in Arizona, where monsoon storms have greatly increased the seasonal rainfall totals. Since June 1, Flagstaff has received over 10 inches of rain, which is nearly 140% of average. Phoenix has reported nearly 170% of its average since the start of June.
In California though, rain has been seriously lacking, with over 45% of the state in exceptional drought, according to the United States Drought Monitor. The Los Angeles International Airport has reported 0.12 of an inch since June 1, all of which occurred on July 26. That was the last time measurable rain fell at LAX, and the first time since March.
While rain can be a relief in drought-stricken areas, too much rain falling at once can lead to flash flooding issues as the dry ground, which is less porous than regular earth, can't absorb the rainfall fast enough and the water runs off instead.
And where rain doesn't fall, dry lightning can still occur, raising the risk for wildfires across such a dry area. Dry lightning is a term used during a thunderstorm that produces little to no rainfall. These lightning strikes can light dry vegetation and spark wildfires easily.
As of Monday morning, 10 large active fires are burning across California, the second most of any state in the United States, and two in Nevada, according to the National Interagency Fire Center. The Dixie Fire, located in Northern California, has burned more than 963,000 acres of land so far and continues to burn.
Another pattern change is in the works for the Southwest later in the week and into the weekend as another deep dip rides into the Pacific Coast, bringing more cool air, high winds and even high-elevation snow into the Southwest.
For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.
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News / Weather Forecasts
Long-awaited wet weather to arrive in Southwest
By Jessica Storm, AccuWeather Meteorologist
Updated Oct 4, 2021 8:43 PM EDT
Have you ever wondered what you're breathing into your lungs if you inhaled wildfire smoke? It’s not just the smoke that can drastically impact your health.
Wet and humid weather is on the way to the Southwest this week, which could even produce the first measurable rain at the Los Angeles International Airport since July and cause locally heavy downpours at higher elevations.
Ahead of the rainy shot, hot and dry conditions continued across the region this past weekend, providing high temperatures in the upper 80s in Los Angeles on Sunday, over 10 degrees Fahrenheit above average. Las Vegas had temperatures around 90 F on Sunday, just a few degrees above the typical high temperature of 88 F.
However, cooler and wetter conditions will be rushing into the Southwest within the week. It will be rather unsettled and cloudy across Southern California on Tuesday, according to AccuWeather Senior Meteorologist Mike LeSeney.
A thunderstorm that moved through the Los Angeles area late Monday afternoon caused a delay in the Monday Night Football matchup between the Los Angeles Chargers and the Las Vegas Raiders.
Heavy rainfall from showers and thunderstorms is expected across much of the Southwest, especially in California, Nevada and Arizona. AccuWeather forecasters are predicting a possible thundershower in downtown Los Angeles on Tuesday, though the heaviest precipitation is expected to stay mainly in the mountains.
A dip in the jet stream will develop into a "cut-off" area of low pressure offshore southwest of Southern California this weekend, according to LeSeney.
Low pressure that is "cut off" is also known as a closed area of low pressure in the upper levels of the atmosphere that has become completely displaced from the typical westerly current.
"This upper-level low will then spin its way towards the Southern California coast and will move ashore Monday night," said LeSeney.
Showers and thunderstorms will form generally on Tuesday from Southern California to western New Mexico, moving into the Four Corners region on Wednesday.
"Cold air aloft will be stacked overtop warmer air at the surface resulting in atmospheric instability and the formation of showers and thunderstorms, especially over the higher terrain of the mountains," explained LeSeney.
Heavy thunderstorms can impact places like Flagstaff and Sedona, Arizona, on Tuesday afternoon. Temperatures will also drop drastically on Tuesday, including in Flagstaff, where the high temperature is anticipated to remain at least 10 degrees below average and in the middle 50s. Los Angeles is forecast to have high temperatures in the refreshing middle to lower 70s on Tuesday and Wednesday.
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"This storm will also bring in more humid air which may result in locally heavy rainfall, especially during the afternoon and evening hours when showers and thunderstorms may be most numerous," said LeSeney.
Despite most of the Southwest experiencing drought conditions, these heavier storms bring the chance of flooding, especially in Arizona, where monsoon storms have greatly increased the seasonal rainfall totals. Since June 1, Flagstaff has received over 10 inches of rain, which is nearly 140% of average. Phoenix has reported nearly 170% of its average since the start of June.
In California though, rain has been seriously lacking, with over 45% of the state in exceptional drought, according to the United States Drought Monitor. The Los Angeles International Airport has reported 0.12 of an inch since June 1, all of which occurred on July 26. That was the last time measurable rain fell at LAX, and the first time since March.
While rain can be a relief in drought-stricken areas, too much rain falling at once can lead to flash flooding issues as the dry ground, which is less porous than regular earth, can't absorb the rainfall fast enough and the water runs off instead.
And where rain doesn't fall, dry lightning can still occur, raising the risk for wildfires across such a dry area. Dry lightning is a term used during a thunderstorm that produces little to no rainfall. These lightning strikes can light dry vegetation and spark wildfires easily.
As of Monday morning, 10 large active fires are burning across California, the second most of any state in the United States, and two in Nevada, according to the National Interagency Fire Center. The Dixie Fire, located in Northern California, has burned more than 963,000 acres of land so far and continues to burn.
Another pattern change is in the works for the Southwest later in the week and into the weekend as another deep dip rides into the Pacific Coast, bringing more cool air, high winds and even high-elevation snow into the Southwest.
For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.
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