SALLISAW — A time of year commonly associated with tornadoes in Oklahoma has produced none in the area immediately west of Fort Smith.

National Weather Service officials have not confirmed any tornadoes in Sequoyah or LeFlore counties in 2018 as of Friday afternoon. This fits the larger pattern for all 25 Oklahoma counties Oklahoma covered by the Tulsa National Weather Service office, which have seen two tornadoes this whole year, meteorologist Sarah Corfidi with the Tulsa office said.

Since 1950, there have been about 300 tornadoes in the month of April and over 460 in the month of May in the Tulsa office's region, which also covers seven counties in northwest Arkansas and the Fort Smith region, Corfidi said.

“May is usually our biggest month," Sequoyah County emergency management director Steve Rutherford said of tornadoes in his county. "This year it wasn’t, so we’re just kind of looking at what’s going to happen for the rest of the year.”

Corfidi explained that the lack of tornadoes in Oklahoma this year is due to abnormal weather patterns in the state during April and May. She said an April that had below-average temperatures followed by a May with record highs disrupted the usual jet stream that brings severe weather through Oklahoma and Kansas.

As of Friday, Corfidi said, the jet stream was flowing through South Dakota and Nebraska.

"Into mid-June, it starts to be more climatologically favored to have storms in the northern and central plains, rather than the southern plains," Corfidi said.

Most of the tornadoes confirmed by the Tulsa office have been in the Fort Smith region in Arkansas, with Sebastian and Franklin counties each having three apiece. The most severe tornado in the region was a EF-2 on April 13 that damaged approximately 160 structures and injured four people in the Mountainburg area in Crawford County.

The only two Oklahoma tornadoes in the Tulsa office region have been in Osage County, just northwest of Tulsa.

“It depends entirely on the weather situation in that time of the year, whatever that is, and the fronts and how they come in, and the storms themselves and what those storms are doing," Rutherford said.

Though the late spring and early summer months typically produce more tornadoes than any other time of year in eastern Oklahoma, Rutherford said they are not limited to any specific month. He said tornadoes have hit Sequoyah County in every calendar month dating back to 1950.

Corfidi said winter tornadoes typically hit Oklahoma before a cold front happens.

“We’ve had it where we have severe weather going on in southeast Oklahoma, but we have ice ongoing in northeast Oklahoma," Corfidi said.

"I’ve seen them at midnight, and I’ve seen them at three in the afternoon. You can’t pinpoint them. It just depends entirely on the frontal movements and how the storms build," Rutherford said.

When tornadoes do hit Sequoyah County, they often begin there and move other places, Rutherford said. He said tornadoes that originate in Sequoyah County sometimes move south into LeFlore County, and that tornadoes that originate in LeFlore County often move north into his area. Rutherford also said he has seen tornadoes move east into Arkansas.

With these things in mind, Rutherford is staying prepared.

"I tell all of the people who work with us, ‘You never know what month it’s going to hit, so just be ready.’ Since I’m on the chat room with the weather service, I usually give them a heads up early in the day and say, ‘Hey, they’re saying we might have storms this afternoon. We might get some storms later in the day, so be ready. If I holler, come on in,’” he said.