Monsoon intensifies, higher chances of storms through Monday evening

Posted: Updated:
PHOENIX (3TV/CBS 5) -

The monsoon is expected to intensify Sunday evening, and that means a better chance of storms moving into the Valley through Monday morning.

An inverted trough situated across southeastern Arizona, deep moisture, decent dynamic forcing and higher instability will fuel thunderstorms, that could be severe at times, from the high country through the Valley.

Storms will develop first along the Mogollon Rim, White Mountains and SE Arizona late this morning and this afternoon. Steering flow will come from the east and southeast, so there's a good chance for storms and outflows to move into Metro Phoenix this evening and into early Monday morning. Some of these storms will be capable of damaging winds and large hail.

These storms are also expected to be slow-movers, so with abundant moisture to work with, flash flooding will also be a threat from the mountains to the Valley. Blowing dust is also a possibility.

Storm chances remain elevated through Monday before the inverted trough tracks northward. This will open the door for a drier air mass to start moving into Arizona for Wednesday and Thursday, decreasing the amount of storms we see in Arizona, and dropping storm chances for the Valley.

High pressure will reposition itself across the Four Corners region by the end of the week and into next weekend, reigniting monsoon conditions and increasing storm chances once again.

In Metro Phoenix, look for a high of 99 today with a 20 percent chance of storms after 11 a.m. Storm chances increase to 40 percent this evening and into the overnight hours.

For Monday, a high of 97 degrees with a 30 percent chance of storms is in the forecast. Storm chances drop to 20 percent Tuesday and 10 percent Wednesday, as highs rise back up to the low 100s.

[SPECIAL SECTION: Weather]

Click/tap here to download the free azfamily mobile app.

Copyright 2017 KPHO/KTVK (KPHO Broadcasting Corporation). All rights reserved.


  • Arizona's Family Weather BlogMore>>

  • Keeping outside rabbits (and other critters) cool in the heat

    Keeping outside rabbits (and other critters) cool in the heat

    Thursday, April 26 2018 10:20 PM EDT2018-04-27 02:20:02 GMT
    Royal Norman with his bunnies. (Source: 3TV/CBS 5)Royal Norman with his bunnies. (Source: 3TV/CBS 5)
    Royal Norman with his bunnies. (Source: 3TV/CBS 5)Royal Norman with his bunnies. (Source: 3TV/CBS 5)

    Rabbits and other critters are fun as pets. But we have to make sure as it gets hot outside that we take care of them.

    More >

    Rabbits and other critters are fun as pets. But we have to make sure as it gets hot outside that we take care of them.

    More >
  • This week's pollution problems

    This week's pollution problems

    Wednesday, April 25 2018 6:20 PM EDT2018-04-25 22:20:48 GMT
    Lots of sunshine and lights winds aren't helping the ozone pollution. (Source: 3TV/CBS 5)Lots of sunshine and lights winds aren't helping the ozone pollution. (Source: 3TV/CBS 5)
    Lots of sunshine and lights winds aren't helping the ozone pollution. (Source: 3TV/CBS 5)Lots of sunshine and lights winds aren't helping the ozone pollution. (Source: 3TV/CBS 5)

    This week's combination of unseasonably warm temperatures and light winds has brought a big pollution problem. You can't see ozone pollution, but it's pretty dangerous to your health. 

    More >

    This week's combination of unseasonably warm temperatures and light winds has brought a big pollution problem. You can't see ozone pollution, but it's pretty dangerous to your health. 

    More >
  • Running with pride at Pat's Run

    Running with pride at Pat's Run

    Saturday, April 21 2018 1:16 AM EDT2018-04-21 05:16:53 GMT

    It’s a big weekend here in the Valley as we celebrate the life of Pat Tillman and honor him and raise money for military members. I will be running with pride this weekend, after my brother Erich’s promotion that took place in Washington DC.

    More >

    It’s a big weekend here in the Valley as we celebrate the life of Pat Tillman and honor him and raise money for military members. I will be running with pride this weekend, after my brother Erich’s promotion that took place in Washington DC.

    More >