It could be a hot, dry summer this year in Kansas City — as well as for Missouri and surrounding states.
Look to the Pacific Ocean for the reason. One of the strongest El Niños on record is quickly weakening and appears to be shifting to La Niña.
“If you look at the historical records of the last 80 years, when you transition from El Niño directly to La Niña, the summer that is involved is usually warm and dry,” said Tony Lupo, a professor of atmospheric science at the University of Missouri in Columbia. El Niño weather patterns are associated with a warming of the central and eastern tropical Pacific, while La Niña events are the reverse.
There seems to be a correlation between this type of transition and hot, dry weather, Lupo said.
“El Niño plays a role in the path of the jet stream,” he said. “When we undergo this transition, the jet stream is further north, which allows the sun to really heat up the continent.”
It’s drier, too, because the storms that produce rain follow the jet stream away from states in the central and south-central part of the country.
Lupo said he’s not sure how much warmer this year will be compared with average temperatures.
“We had the same prediction in 2012 when things were in a La Niña-type pattern,” he said. “Of course, that summer was ridiculously hot and dry.”
That year ended up being the third-warmest and -driest summer in the central part of the country, only behind the summers of 1936 and 1980. But other summers involved in a La Niña were not as bad.
“How much warmer and drier it’s going to be is a little unclear given the statistics,” Lupo said.
However, he doesn’t expect this summer to be as hot as the summer of 2012.
The possibility of a hot, dry summer could be bad news for Kansas City and the surrounding region, which already are experiencing abnormally dry or moderate drought conditions.
As of Tuesday, more than 68 percent of Missouri and Kansas were experiencing abnormally dry or worse conditions, according to the U.S. Drought Monitor. Slightly more than 6 percent of Missouri and 15 percent of Kansas were under moderate drought conditions.
As of Thursday, Kansas City had received 5.33 inches of precipitation for the year. That’s 1.8 inches below normal, which is about 80 percent of the rainfall typical for this point, said Spencer Mell, a meteorologist with the National Weather Service in Pleasant Hill.
“The storm track has been basically to the south of us, where they obviously picked up a tremendous amount of precipitation, especially this (past) weekend,” he said.
Kansas City’s rainfall deficit wouldn’t be too difficult to make up at this point. And relief could be on the way.
“In the short term, we actually look like we are going to be kind of wet,” Mell said.
There’s a strong storm system coming the middle of this week that could bring significant rainfall totals.”
And the long-range outlook is good, with normal to slightly above normal precipitation expected through the middle part of the summer.
“We are not at a dire situation yet,” Mell said. “But we are certainly in need of precipitation.”
One or two good rains would cut into the deficit and the abnormally dry and moderate drought conditions would disappear.
Dennis Patton, a horticulturist with Johnson County K-State Research and Extension in Olathe, said it’s been so dry this year that he had to violate a rule he has about how early each spring he waters his lawn.
In a typical year, he never waters in April — there’s usually enough rainfall in April, May and June that lawns don’t need supplemental moisture. But a week or two ago he watered it.
Gardeners planning their spring plantings might want to consider that it could be a hotter, drier summer, he said.
“You may want to think twice about some of your plant choices and whether or not you are going to take care of the plants if it does turn out to be a hotter, drier summer,” he said.
Gardeners, for example, might want to consider cutting back on annual flowers unless they are willing to care for them. Without that care, the flowers might burn up come July or August.
It’s OK to plan on planting trees, shrubs and other long-term plants.
“Just know that you might have to be a bit more slave to watering,” he said. “What it really boils down to is that if it’s hot and dry, make sure you keep your investments alive.”