Fall is Kansas’ second tornado season. Luckily the first season never got underway

Can you feel it? The slight bite in the air first thing in the morning?

Autumn looks to be arriving a bit early in Kansas this year, weather officials say, which means more time for sweaters and hot cocoa and crisp air. But it could also mean more time for something else: tornadoes.

Kansas has a “second season” for tornadoes in the fall, with warm and cold air masses clashing as the season changes. Yet Kansas hasn’t really had much of a “first season” so far in 2020, which is particularly good news given how injuries caused by a large tornado could strain hospitals already dealing with the COVID-19 pandemic.”

The Wichita branch of the National Weather Service has never gone this deep into a calendar year without a tornado before.

“We’re in the heart of the Plains and we stick out like a sore thumb” with that zero, said Roger Martin, a meteorologist with the Wichita branch. “So that’s pretty telling.”

The Wichita branch has issued only two tornado warnings the entire year. Across the state, only 27 tornadoes have been recorded – many of them weak land spouts.

“It’s just unbelievable,” said Chance Hayes, warning coordination meteorologist for the Wichita branch of the weather service.

Weather officials in the central U.S. are “just completely flabbergasted” at the lack of tornado activity so far this year, Hayes said.

Oklahoma and Texas, who with Kansas make up the heart of Tornado Alley, also have seen remarkably low tornado totals so far this year.

Paul Pastelok, senior meteorologist and head of the Long Range Forecast department at AccuWeather, said unusually dry air in the mid- and upper levels of the atmosphere over the desert Southwest starved Tornado Alley of the juice it needs to generate the supercell thunderstorms that spawn tornadoes.

“It’s getting harder and harder to have a more typical Tornado Alley develop now,” Pastelok said. “It only happens when conditions are absolutely perfect now.”

It’s been an active spring and summer for thunderstorms, weather officials say, but they didn’t develop with all the ingredients needed to produce tornadoes in the Southern Plains.

Kansas hasn’t seen so few tornado warnings issued since 1989, Martin said. That year also capped a stretch when the Sunflower State reached double digits on the number of tornadoes just four times in 14 years.

Weather experts were speculating about whether Tornado Alley was becoming a thing of the past. But the arrival of the 1990s saw a resurgence of tornadoes both in number and ferocity, silencing that speculation.

No one factor is behind the relative lack of tornadoes in Kansas so far this year, meteorologists say. But one significant element is how the jet stream set up this spring, bringing fronts and cooler air down into the Plains from the Pacific Northwest. That consistently brought cooler, stable air into Kansas and blocked warm, moist air from the Gulf of Mexico.

Such patterns typically only last for a few weeks at a time, said Mike Umscheid, a meteorologist with the Dodge City branch of the weather service. But this pattern blossomed in April and lasted all summer. The northwest flow is actually favorable for a wet summer in much of Kansas because by then the upper-level winds aren’t strong enough to keep warm, moist air from the Gulf of Mexico from the Sunflower State.

True to form, it’s been an unusually wet summer in the western part of the state, with numerous night-time thunderstorms rolling through Kansas.

“It’s certainly been a weird season, all the way from April,” Umscheid said.

But tornadoes require a specific combination of conditions to converge before they can form, weather officials say, and one or more of those pieces has been consistently missing in the Wichita area and much of the Southern Plains.

Forecast models suggest the northwest flow pattern could continue well into autumn, Umscheid said, bringing chances for moisture but not the kind of instability that helps fuel tornadoes.

But Hayes cautions against dropping your guard.

“Just because it’s been quiet doesn’t mean it won’t happen and you can’t be complacent,” he said.

Second Season has produced 108 tornadoes since 1950 just in the southeast corner of Kansas managed by the Wichita branch of the weather service. Since the turn of the century, the Wichita coverage area has averaged two tornadoes a year in the fall.

“Just because we’re starting to transition doesn’t mean we’re out of the woods,” Hayes said.

Forecast models indicate that a La Nina pattern, in which surface temperatures in the central Pacific Ocean are cooler than average, will set up late this year. What would that mean for Kansas?

“When you look at past history, that shows an increase in the number of severe storms, including tornadoes and large hail,” Hayes said. “That would lead us to think that this spring definitely could be a busier severe weather season.”

Pastelok is taking a wait-and-see attitude. The La Nina may not be a strong one, he said, and if the cooler temperatures set up in the central Pacific rather than waters farther west, it could well mean historical data carries little weight for 2021.

“We’ll be all finding out new twists” in the weather, he said.

This story was originally published September 8, 2020 at 5:01 AM.