Violent Storm

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A large, violent storm hit the Downtown Phoenix area and the eastern portion of the Phoenix area. Arizona State University climatologist Randy Cerveny will discuss the storm and more.

TED SIMONS: Coming up next on "Arizona Horizon" -- we'll speak with an ASU climatologist on the recent destructive storms to hit the valley. Also tonight, how small businesses can protect intellectual property and we'll learn about an effort to improve civil discourse in politics. Those stories next, on "Arizona Horizon."

NARRATOR: "Arizona Horizon" is made possible by contributions from the friends of 8, members of your Arizona PBS station. Thank you.

TED SIMONS: Good evening. Welcome to "Arizona Horizon." I'm Ted Simons. An effort to recall state superintendent of public instruction Diane Douglas was launched today. The recall group now has 120 days to collect 364,000 signatures to get the recall on the ballot.

MAX GOSHERT: Our coalition is not affiliated with particular political party or endorsing a certain candidate. We represent the people of Arizona have decided that enough is enough when it comes to the lack of leadership and support of education -- lack of support that education service receives in the state.

TED SIMONS: A Douglas spokesman says the recall effort is quote, not on the superintendent's radar at all. A large, violent storm hit central and eastern parts of Phoenix last night. Many residents awoke today to find downed trees and power lines blocking neighborhood streets and major intersections. And at one point last night more than 60,000 homes were without power with more than 30,000 still without electricity this morning. Why are we seeing so many strong, concentrated storms? Is this the work of a developing ElNino weather pattern? For the answers we turn to ASU climatologist Randy Cerveny. Good to have you back, good to see you. Glad you came in because I have some questions for you, mister. What happened last night?

RANDY CERVENY: The kind of storms we get are called convective, they're pop-up, not the kinds you would expect in the Midwest where it's like with a cold front that you have a long line of thunderstorms. These are generated by surface heating. So like the tops of mountains, South Mountain or down south by Tucson. Those mountains can generate enough heat that the rising air will pop up a thunderstorm that is generally pretty short lived but very intense.

TED SIMONS: These pop-up storms, do they usually have this kind of power?

RANDY CERVENY: Well, normally what happens is that they get pushed by upper level winds and so they don't sit over one area for long periods of time. The storm last night didn't move very fast. They were crawling and as they did that allowed more rain to fall then when they collapsed all that wind came out knocking down trees.

TED SIMONS: Oh, they sure did. So many trees in our neighborhood were knocked down. Was this a monsoon storm last night?

RANDY CERVENY: This was classic monsoon. This was something that is typical of what we used to have back in the 80's. We haven't seen quite as many of recently but it's the kind that is incredibly hard to predict. The National Weather Service, local TV meteorologists, we have a hard time predicting these because they are associated with such localized situations. The computer models look a broader view so they can tell you it's going to rain across the valley but they can't tell if it's going to rain over downtown Phoenix or over Tempe.

TED SIMONS: No kidding because everything is fine until they start popping up over what looks like South Mountain and then they kind of either drift over like they did Saturday night and last night or like Sunday night at least in our area they just sat there and made a bunch of rumble and nothing happened.

RANDY CERVENY: Yeah and a lot of times what will generate new storms is that they fall apart they will put out a gust of wind that will kick of more air that will generate a new storm. It depends on how much localized moisture you've got around that to whether you get new storms produced or not.

TED SIMONS: interesting. OK, so if this was a monsoon storm last night, how is monsoon 2015 shaping up?

RANDY CERVENY: Well, for the deserts we're still below the kind of rains that we would expect to see. The high country actually has gotten an even better monsoon than what we've had so far in Phoenix. There are parts of the plateau that are -- the Mogollon rim area that have gotten 100 to 200% of their normal monsoon rainfall. They have done really well, deserts, not so well.

TED SIMONS: For the areas that are doing well, from what we saw last night is ElNino playing a part?

RANDY CERVENY: Well, it's going to play an increasingly larger part here as we go into September and then into the fall. Because normally we start to see a little bit of shift in the way the monsoon works at this time. We'll start to -- you'll start hearing the TV meteorologists paying more attention to tropical storms that are down off the coast of Baja, in fact there's a depression right now that's going to probably influence weather on Thursday here in the metropolitan area. But that's going to become more frequent as we go into September and October. The moisture from those storms, we're not going to get hurricanes but the moisture from the storms are going to get pushed up into Arizona and we'll get more rain.

TED SIMONS: That is ElNino?

RANDY CERVENY: And that is partly due to ElNino.

TED SIMONS: Because usually late September, October, those are pretty dry months.

RANDY CERVENY: Right, but this year the Pacific Ocean is on fire basically so we're getting a lot of storms that made the social media this weekend. We have three category 4 hurricanes that were out in the Pacific Ocean just this weekend alone. We're going to see more of that in the next few months.

TED SIMONS: So the ElNino is still out there; it's still strong. We'll see increasing evidence. Maybe it wasn't ElNino last night although you could have fooled me but we'll see an increasing evidence of that, how is El Nino now shaping up over all?

RANDY CERVENY: It still looking like it's going to be a heck of an impressive fall and winter for us in terms of rainfall. We are predicting over the next three months to be above normal precipitation in the state of Arizona for September, October and November. Pretty much for the United States we are the only state that's going to have above normal precipitation.

TED SIMONS: Interesting. That's September, October, November. ElNinos sometimes don't even start until February, March, April, correct?
RANDY CERVENY: That's right. The forecast is that will continue on. That as we get into the wintertime that precipitation should actually continue.

TED SIMONS: So with this tropical storm now nearby Baja we got other activity maybe happening later, could we see a repeat of this kind of business Saturday night and last night?

RANDY CERVENY: Yeah, and if you remember this time last year we started to see some of those very kinds of effects of the moisture from tropical storms causing so much damage with heavy, heavy rains over the state, the last year at this time. We could see that again.

TED SIMONS: Last question, very quickly. Obviously, one season does not end a drought. Couple of these in a row, could that put a serious dent in the drought?

RANDY CERVENY: Oh, absolutely. Any moisture we get is going to help and this because we're anticipating above normal rainfall should put a pretty good dent for Arizona's drought. May not be quite as good for California because they are much deeper into the drought than we are but we'll get some support from all the rain.

TED SIMONS: Alright Randy, good to have you. Thanks for joining us.

Randy Cerveny: Arizona State University climatologist

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