SACRAMENTO, Calif. — In the doldrums of summertime, much of the American Southwest has been baking under unrelenting heat. But, it isn't supposed to be this way day-in and day-out. Believe it or not, it's supposed to be raining.
"It's really the rainiest time of year for places like Tucson, Arizona; Albuquerque, New Mexico; Phoenix, that area," said Dr. Dan McEvoy, a climatologist with the Western Regional Climate Center, part of the Desert Research Institue. "Las Vegas also can get quite a bit of precip from the monsoon."
Of course, we expect it to be dry this time of year in Northern California. We get most of our rain during wintertime atmospheric river events, unlike Arizona and New Mexico, which depend on the monsoon for the bulk of their rain.
This year though, the proverbial monsoonal taps have been slow to open up.
"Overall, it's been a very slow start to the monsoon," said McEvoy. "And I kind of like the term that – I don't know who started using it – but 'nonsoon', when these monsoons don't really show up."
"Just about no rainfall in Albuquerque. Phoenix [had] one of its driest Julys. There was some spotty, decent monsoon rain, for example, Tucson, further south in Arizona, got about two inches in July, but that was still below average for the year. So the entire region is well below average. And with that lack of clouds and rain, it's been extremely hot in that region as well," said McEvoy.
A dry monsoon – or "nonsoon" – isn’t necessarily a water supply problem, as most of that comes from winter snowpack in the Rockies.
"It's more about keeping the healthy landscape and vegetation, and also reducing fire danger for that region," said McEvoy. "Because if (it) continues to be hot and dry, like we've seen this year, then the fire danger can persist well into the summer."
A persistent high pressure, largely set up over southern Arizona and New Mexico over the past month, has brought a record-setting stretch of high temperatures. However, it also has kept the region largely dry.
"So what that's doing is with the clockwise circulation around the high-pressure system, just being that a little bit further south, it's not able to draw in the moisture from the big water bodies like it does," said McEvoy. "And so this is setting up to kind of have drought conditions start developing again."
Still, hope isn’t lost. The monsoon season still has another month or so to go. The monsoon season officially started on June 15th, and it goes through September.
"The kind of shorter-term forecasts, at least for the next week or two, still show it being quite dry and hot with really no monsoonal moisture returning that could change," said McEvoy. "There is hope and a chance that it could return for a late start to the monsoon which would help. I think it'll still be tough to make up the seasonal – like the total monsoon deficits that have already occurred as the monsoon period is about halfway over."
Watch more from ABC10: Extreme heat returns for Northern California weekend
