Showing posts with label numbers. Show all posts
Showing posts with label numbers. Show all posts

Friday, April 11, 2025

Yes, The United States HAS Had A Lot Of Tornadoes This Year

A massive tornado in Lake City, Arkansas on April 2.
So far, this has been a very busy season for 
tornadoes in the U.S.
 If you been thinking that almost all you've heard in weather news this spring is tornadoes, there's a reason for it. 

The United States has had an exceptionally busy early part of tornado season. Through April 7, there have been 473 tornadoes. 

On average by April 7, there's normally about 270 tornadoes this far into the season, according to NOAA's Storm Prediction Center. 

That doesn't necessarily mean that will continue, but for now, we're way ahead of normal.

March got things off to a rousing start and the first week of April was even worse. A lull in tornado activity started on Monday and will probably last at least a week during which few tornadoes will touch down. 

But there are tentative signs that things could get really busy again toward the end of the month as we head toward the heart of tornado season. (Tornadoes activity usually peaks in May and early June).

 MARCH

There were no fewer than 175 confirmed tornadoes in March, and that number might go up as other reports are confirmed.

That's double the amount the United States usually sees in March..

March was punctuated by an unusually large tornado outbreak in the middle of the month with 116 twisters reported.  That's a big outbreak for any time of year but it's really odd for so early in the season. 

 The two busiest years for March tornadoes were 234 in 2022 and 208 in 2023.  Part of the issues is weak tornadoes are better detected than they were years and decades ago, so those are added to the count. 

March is usually just the beginning of tornado season. The vast majority of U.S. tornadoes strike in April, May and June. 

APRIL

April got off to an explosive tornado start. So far, no fewer than 182 tornadoes have been counted in the first seven days of April. That number -  182 - happens to be the average number of tornados for an entire April.  That's easily one of the busiest early Aprils on record. Through Monday, tornadoes had been reported somewhere in the U.S. on 12 consecutive days. 

That's the earliest in the year on record in which there were at least ten consecutive days with tornadoes.

As noted above, we have a lull going in tornado activity. Especially given super April tornado outbreaks in 1974 and 2011, I doubt there will be record number of twisters this month. Still forecasters are expecting at least the possibility of a notable uptick in severe storms and tornadoes toward the end of this month. 

Generally speaking more tornadoes occur in late April rather than early in the month. 

The record for April twisters is 757 in 2011. Interestingly, last year had the second highest number of April tornadoes with at least 356 twisters.

By the way, last year was the second busiest tornado year on record, with just under 1,800 twisters in the U.S,

LA NINA/CLIMATE CHANGE

However, the Washington Post reports that the increase in March tornadoes in recent years can't be fully explained by better counting. 

Part of it might be La Nina, a periodic cooling of eastern Pacific waters. One of the effects of that cooling is a wavier jet stream across the continental United States. A wavy jet stream means more and stronger storm systems. 

If these storms can produce the correct clash of warm, humid air from the south and frigid air from the north, and adequate shifting winds in the atmosphere, you get tornadoes. 

Both 2022 and 2023, those busy tornado Marches, were La Nina years.

La Nina has pretty much faded away, so that will probably be no longer much of an influence on the rest of tornado season. The second reason for so many tornadoes might not go away so fast. And this second reason has to do with climate change.  The Gulf of Mexico is toastier than normal, a trend that has been consistent in recent years as a warmer atmosphere also heats up the oceans. 

When the Gulf water is warmer, it allows even more moisture to stream northward into the kind of storm systems that spin off tornadoes. Humid air is a key ingredient for tornadoes, so the more moisture the merrier, at least from the perspective of twisters. 

La Nina is fading. And besides, the effects of La Nina tend to fade as we head further into spring.

However, warm Gulf of Mexico waters do influence tornadoes well into spring and early summer. 

That's not to say the rest of tornado season will be supercharged. It just increases the odds somewhat. 

But you never know what will happen. March, 2012 was a busy and tragic month for tornadoes, with 223 twisters reported. 

That month was punctuated by an intense tornado outbreak on March 2-3 that produced 81 tornadoes which killed at least 40 people.

But it turned out the rest of the 2012 tornado season was pretty unremarkable. The year ended up with about 1,000 tornadoes, Which seems like a lot but was still about 300 below normal.

By contrast, there weren't many tornadoes in March and early April, 2004. But the year turned out to have the most tornadoes on record, with 1,819 twisters, including 389 in just the final 11 days of May that year.   Tornado deaths that year were mercifully low considering the numbers, amounting to 35 people 

That's tragic of course, but fewer than in many of the slowest tornado years.  

Friday, September 29, 2023

Running Out Of Atlantic Tropical Storm Names Again?

Hurricane Lee off the U.S. East Coast on Sept. 14.
There's been a near record number of tropical
storms and hurricanes in the Atlantic this year. 
 It might not seem it, but it's been an incredibly busy tropical Atlantic hurricane season so far. 

At the moment, Tropical Storm Phillippe is wandering aimlessly in the central Atlantic. Tropical Storm Rina also formed way out there the other day. 

Another trailing system has a decent shot at building into a tropical storm.  The hurricane season lasts through November. And there's now only four names left on the 2023 hurricane or tropical storm list: Sean, Tammy, Vince and Whitney

It doesn't seem like it's been that busy because most storms have mercifully not made landfall.  So far, only Hurricanes Idalia and Lee, and Tropical Storm Ophelia have caused much trouble in the United States. Yeah, they were all bad, but it could have been a lot worse. 

Most tropical storms and hurricanes have stayed out over water. Many of them moved north into colder water and petered out without causing any harm. 

If we run out of hurricane names this year, it will be third time that's happened. 

The first time the Atlantic Ocean basin ran out of names was the horrid season of 2005. That's the year that brought us the huge disasters Hurricanes Katrina, Rita and Wilma, along with other destructive land falling hurricanes in the United States. 

In 2005, they resorted to using Greek names to deal with the last six tropical storms in the Atlantic basin.

Then came 2020 with a total of 30 named storms.  The National Hurricane Center ran through their name list early that season, resorting to the last of the names on the official list with Tropical Storm Wilfred on September 17, barely past the halfway point of the hurricane season. 

The rest of the 2020 season featured a confusing list of Greek named storms, including Delta, Zeta, Eta and Theta.

The whole point of naming tropical storms and hurricanes is to avoid public confusion. If two storms with distinct names happen at the same time, like this year's Hurricane Lee and Margo, it's easy to tell which one is which, and which hurricane you should worry about, and which one you can safely ignore. 

To solve the Greek letter problem if there are too many hurricanes and tropical storms, the World Meteorological has come up with a "B" list of sorts, names to use in the event we run out. So, if we get past Whitney in the Atlantic this year, we'll then go with Adria, Braylen, Caridad etc.   

It's a little odd that there have been so many tropical storms this year.  We're now in an El Nino pattern, which tends to squelch Atlantic tropical storms and hurricanes due to strong upper level winds.

Those winds have materialized due to El Nino. But the Atlantic Ocean is at record warm levels, which is jet fuel for wannabe tropical storms. So, tropical storms are forming left and right. The strong upper level winds are keeping many of these storms, like the current Phillippe and Rina on the weak side, so I guess we can be happy for that.