Busy spring severe weather season slowly wanes

Yahoo

24-05-2025

The spring severe weather season is winding down, but it leaves behind a trail of destruction, following one of the most active periods for tornado activity in more than a decade.
Between the start of March and the end of May, the Storm Prediction Center received over 900 preliminary tornado reports - significantly above the seasonal average of around 600, based on historical data from the 1990s and 2000s.
Despite the activity, the year began on a relatively quiet note, with January only seeing 20 tornado reports, followed by 41 in February - both below average.
April proved to be the busiest month of the year for tornadoes, with 351 reported across the country.
The tally made the month the third most active April on record, behind only 2024 and 2011.
The most intense tornado outbreak of the season occurred in mid-March, when energy from an atmospheric river event fed into a developing storm system, which produced more than 100 tornadoes, including at least three that were rated as EF4 on the Enhanced Fujita Scale.
Absence Of Ef-5 Tornadoes May Be Because Of Damage Assessments, Not Changes In Weather Patterns
The largest number of tornadoes during a single outbreak occurred in early April, when more than 150 tornadoes plowed across much of the central U.S.
The deadliest event happened in May, as violent storms swept across Missouri, Indiana and Kentucky, killing at least 27 people.
The most destructive tornado during that outbreak tore through London, Kentucky, and was rated EF4, with estimated winds of 170 mph, according to the National Weather Service.
Despite the devastation, the EF4 twister in the Bluegrass State was not the strongest of the year - that distinction belongs to a tornado that occurred near Diaz, Arkansas, in mid-March.
Wind speeds during the EF4 were estimated to be at least 190 mph, which is just about 10 mph shy of being designated an EF5.
Fortunately, the tornado spared significant population centers, and no fatalities were connected to the event.
Notably, there have been no EF5 tornadoes reported in 2025, continuing a 12-year drought of the most violent category of a twister.
The last EF5 tornado in the U.S. struck Moore, Oklahoma, on May 20, 2013, with winds of around 210 mph.
Some researchers argue that surveying methods have led to fewer EF5 classifications, rather than a genuine shift in weather patterns.
Through the first five months of the year, Missouri and Illinois have seen the highest number of tornadoes, with initial counts of 105 and 104, respectively.
These totals are far above those of traditional tornado-prone states such as Kansas and Oklahoma, which reinforces a growing consensus among some forecasters that "Tornado Alley" is indeed shifting.
Why Tornado Alley Is Shifting East
Even though meteorological spring ends in May, severe weather threats don't disappear with the turn of the calendar.
Thunderstorms can impact most of the Lower 48 year-round, but widespread events triggered by cold fronts become less frequent in the southern U.S. as summer takes hold.
During the summer months, severe weather threats often stem from different atmospheric phenomena such as derechos and sea breeze collisions.
Derechos are long-lived complexes of thunderstorms, which often travel along the rim of high-pressure systems.
Further south, sea breeze interactions often fuel near-daily thunderstorm activity across Florida and the Gulf Coast.
Later in the season, tropical cyclones may enter the picture, some of which can produce dozens of tornadoes, but tornado outbreaks associated with tropical systems are not yearly occurrences.
June still remains an active month for tornadoes, especially across the Northern Plains, though there is a noticeable decline in activity by July.
A secondary severe weather season typically returns to the South in November and December, as frontal boundaries make their return ahead of winter.Original article source: Busy spring severe weather season slowly wanes