The 2023 tornado season is ramping up

The 2023 tornado season is starting out to be an active one, especially in the southern U.S. Just over a week ago, March 24-27, there were 30 twisters, including one EF4, that resulted in catastrophic damage in Rolling Fork and Silver City, Miss. Additional tornadoes were spawned March 31 and April 1 across a large region of the Mississippi Valley, as well as parts of the Midwest. As of late Saturday, there were 18 twisters reported from this outbreak. The long-range weather charts are indicating the potential for more severe weather across the central U.S. into at least the middle of this month.

Many of this year’s tornadoes also occurred in January. On Jan. 2-4, a three-day severe weather outbreak impacted the southern U.S. with 58 twisters. The Southeast was hit Jan. 12 with 41 tornadoes. Another outbreak occurred Feb. 26-27 with 30 tornadoes reported from Oklahoma, heading north-eastward into Illinois, Indiana and Ohio.

According to the Storm Prediction Center, there have been 311 tornadoes reported during the first three months of 2023. With more severe storms expected in April, it’s possible that we’ll see a very active tornado season across the country.

Last year, there were 1,152 confirmed tornadoes across the U.S., very close to normal. Total damage was near $480 million with 23 fatalities. The strongest tornado last year was the Byran County tornado in Georgia. On April 5, an EF4 twister hit the region with estimated winds of 185 miles per hour.

The most intense tornadoes are EF5, which is the highest on the Saffir-Simpson Scale. The last time the U.S. reported a twister that strong was May 20, 2013, in Moore, Okla. One of the most devastating seasons was back in 2011 when there were multiple EF-5 twisters reported.

In an average year, there are about 1,200 tornadoes sighted in the U.S. In 2021, there were an above normal 1,313 confirmed twisters that resulted in about $7.7 billion in damage, which was considerably higher than last year. More than 60% of all U.S. tornadoes each year occur in what is called, "Tornado Alley," which stretches from Texas and Oklahoma northward through Kansas and eastern Colorado into Nebraska and Iowa.

During the spring season, cooler air from the north will collide with warmer air from the south. The Gulf of Mexico also provides a moisture source. This combination, along with a few other factors, sometimes will result in conditions very favorable for the formation of small to intense tornadoes.

Although, the spring season is the most common occurrence for tornado formation, there have been outbreaks at other times of the year, including the winter months. On Feb. 5-6, 2008, a storm system spawned 84 tornadoes and hit the southern U.S. across four states.

The U.S. receives more tornadoes than any other country. In fact, there are four times more twisters here than in Europe. In recorded history, tornadoes have been seen in all 50 states. In Alaska, there were two twisters reported, one in November of 1959 and the other in August of 2005. Both were on the very low end of the intensity scale. Since 1950, Hawaii has seen 40 tornadoes. The last one, reported March 17, 2000, was an EF0 seen near Waimea.

One of the most active months for tornadic activity in the U.S. is in May. The average number of tornadoes for May is 276, with the majority occurring in Texas (43), Oklahoma (28) and Kansas (38). Both Idaho and Washington average one tornado during the month of May. For an entire season, the average number of twisters in Idaho is four.

The intensity of a tornado is currently measured by the Enhanced Fujita Scale, which was implemented in 2007. It examines the damage caused by the twister and wind speeds. An EF0 and EF1 tornado generally inflicts minor damage, but an EF5, the most severe, will cause widespread destruction. Prior to the enhancement, the Fujita Scale was used based on the damage of structures and area vegetation.

Here in North Idaho, our chance for severe weather increases during the spring season. Cliff and I are predicting an above normal precipitation pattern for April, and perhaps into May, as the jet stream moves northward from California. After this weekend, the chances for bigger snows are low. However, we can’t forget the 7.8 inches of snow that fell last year April 15. One of the long-range computer models is pointing to the possibility of more snow around the middle of month. Prior to that, we’ll likely have high temperatures near 70 degrees. Again, one extreme to the other in short order.

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Contact Randy Mann at randy@longrangeweather.com.