Upper low helps send monsoonal moisture into California and beyond
By
Brian Thompson, AccuWeather meteorologist
Updated Jul 25, 2021 11:12 AM EDT
An upper-level low is going to pull monsoonal moisture to the north and west through the early part of this week, bringing the risk for thunderstorms into California.
As the core of the moisture gets pulled away from the Four Corners, there will be a bit of a break in the thunderstorms for much of Arizona heading into the middle part of this week.
The upper low is over Arizona as of Sunday morning, which will lead to a very active day of thunderstorms and the potential for flash flooding across the state.
This feature will move to the west and northwest over the next couple of days. This will push the threat for showers and thunderstorms more into California and Nevada over the next couple of days.
By Monday, there's a fair amount of energy sliding through Southern California. This will lead to some showers and thunderstorms across that area as well as southern Nevada through the day.
This round will not just be limited to the Sierra or the higher terrain. With this energy pushing through, we'll see some showers and storms in some coastal areas as well.
The threat for these showers and thunderstorms will shift northward into Northern California, northern Nevada and parts of Oregon Monday night into Tuesday as the energy rotates clockwise around the broad ridge to the east.
Toward the middle of next week, the threat for showers and storms will shift more toward central and eastern Oregon as well as Idaho.
Any rain is certainly good news for a lot of this area, and hopefully the impressive surge of monsoonal moisture will allow these storms to put down decent rainfall in some areas.
In fact, it wouldn't be surprising to see some flash flooding given just how much moisture there is.
Precipitable water values will be up over 2 inches in spots, which will allow some of these storms to dump a lot of rain.
However, the lightning is always a concern in setups like this.
Some areas will get a decent amount of rain, but even if a storm is producing a fair amount of rain, the lightning can strike outside of where it's raining, which can provide a spark on dry ground.
The dry lightning risk may increase the farther north you go, as the moisture will not be as copious by the time this energy sparks storms in Oregon and Idaho by Tuesday and Wednesday.
Meanwhile, as the monsoonal moisture shifts, much of Arizona will get a break during the first half of the week. While there will be some spotty storms in the mountains, the coverage will not be widespread as what we've been seeing.
The coverage of storms will start to pick back up again later in the week.
Report a Typo
Weather Blogs / Western US weather
Upper low helps send monsoonal moisture into California and beyond
By Brian Thompson, AccuWeather meteorologist
Updated Jul 25, 2021 11:12 AM EDT
An upper-level low is going to pull monsoonal moisture to the north and west through the early part of this week, bringing the risk for thunderstorms into California.
As the core of the moisture gets pulled away from the Four Corners, there will be a bit of a break in the thunderstorms for much of Arizona heading into the middle part of this week.
The upper low is over Arizona as of Sunday morning, which will lead to a very active day of thunderstorms and the potential for flash flooding across the state.
This feature will move to the west and northwest over the next couple of days. This will push the threat for showers and thunderstorms more into California and Nevada over the next couple of days.
By Monday, there's a fair amount of energy sliding through Southern California. This will lead to some showers and thunderstorms across that area as well as southern Nevada through the day.
This round will not just be limited to the Sierra or the higher terrain. With this energy pushing through, we'll see some showers and storms in some coastal areas as well.
The threat for these showers and thunderstorms will shift northward into Northern California, northern Nevada and parts of Oregon Monday night into Tuesday as the energy rotates clockwise around the broad ridge to the east.
Toward the middle of next week, the threat for showers and storms will shift more toward central and eastern Oregon as well as Idaho.
Any rain is certainly good news for a lot of this area, and hopefully the impressive surge of monsoonal moisture will allow these storms to put down decent rainfall in some areas.
In fact, it wouldn't be surprising to see some flash flooding given just how much moisture there is.
Precipitable water values will be up over 2 inches in spots, which will allow some of these storms to dump a lot of rain.
However, the lightning is always a concern in setups like this.
Some areas will get a decent amount of rain, but even if a storm is producing a fair amount of rain, the lightning can strike outside of where it's raining, which can provide a spark on dry ground.
The dry lightning risk may increase the farther north you go, as the moisture will not be as copious by the time this energy sparks storms in Oregon and Idaho by Tuesday and Wednesday.
Meanwhile, as the monsoonal moisture shifts, much of Arizona will get a break during the first half of the week. While there will be some spotty storms in the mountains, the coverage will not be widespread as what we've been seeing.
The coverage of storms will start to pick back up again later in the week.
Report a Typo