Through the end of March, 2015’s tornado drought is among the biggest on record

April 7 update: As mentioned in the original text, there are perils to writing about current tornado numbers too quickly. At least 4 additional tornado reports came in late to SPC after the article was completed. They were all from March 31 in Arkansas, the southeast part of the state on top of the warnings shown in the map above. This brings the March preliminary to 13 per NOAA accounting. Please consider that change when looking at the stats below. I generally bounded them with the expectation that numbers could increase to about this level, so the place in history can still be well judged by reading!

Original post from April 1 at 9:10 a.m. EDT: March 2015 will be remembered for being as quiet as it gets for tornadoes. Twisters slept till late in the month as cold air dominated the eastern two thirds of the country. Despite the low numbers, one was fatal on March 25.

The month just ended was only part of a historically timid start to the 2015 tornado year. Seemingly the continuation of a trend in recent years?

While we expect the March-May period to finish below average for tornadoes, it appears an uptick in activity should be along as we get into April. Spring will of course take hold eventually.

In the meantime, let’s take a quick look at where we are and how it compares…

Note: For this analysis, I am focusing on 2008-present, largely because 2008 is the first full year with nationwide implementation of storm-based tornado warnings.

Tornadoes have been reported on seven days through the first quarter of 2015. In the prior seven years ending 2014, the one with the fewest tornado days over the same period was 2014 at 12. The year with the most tornado days during the January through March period was 2012 with 35.

Related: U.S. tornado days averages | Strong tornado days

No matter how you slice it, we’re at the bottom of the tornado barrel right now. Confirmed tornadoes for March 2015 should end up in the 6-10 range. A graph of all March tornadoes by year is below. The least productive seven years — those with fewer than 20 tornadoes — are highlighted in bright red.

While it appears March 2015 should, in final accounting, finish just above the least tornadic March in 1951 — when six were recorded — it’ll end up close to the second lowest March total of 8 in 1969. The other years with fewer than 20 March touchdowns are 1966 (12), 1958 (15), 1978 (17), and 2013 (18). 2014 just eked out of that grouping at 20.

On the other end, 1976 is the leader for the month with 180 tornadoes. Recent years like 2007 (170) and 2012 (154) fall into the top five most productive.

The three-year running stretch for March has been historically tame as well. About 50 twisters have touched down during the month since 2013. That easily undercuts any three-year period for futility, with 1968-70 the only other contender at 61 tornadoes.

March 2013, 2014, and 2015 all rank in the top 10 quietest for the month in the modern record.

Related: March tornadoes by the numbers | Where tornadoes form in March

But it’s not just March, as the tornado day count above alludes to. Given the lack of days with tornadoes, counts of tornado warnings, and tornadoes themselves are way down this year compared to recent times.

It’s almost hard to imagine 2008 right now.

Through this point, that year had more than 15 times as many tornado warnings as this one, and more than 10 times the tornadoes. Then there’s 2012, which started off with a bang then sort of petered out after the early season, ending up below normal for the year (as we’ll see below).

Given that the tornado record is kind of messy, especially as it’s being compiled, I’m not going to delve too deep into long-term comparisons. But, the preliminary count in the neighborhood of 32-38 tornadoes this year is also running in the top five least productive.

1969 safely holds the three-month record with 16 tornado touchdowns for the first quarter of the year. 1951 had 18 tornadoes, for second least. 2015 apparently falls in between 1951 and the next on the list, 1968, which had 40 tornadoes January through March.

Here’s how the graph above looks in map form, looped from 2008 to 2015:

You can check out each individually as well –> 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014 | 2015

Seven years (not including 2015) is too short of a period to come away with a bulletproof average, but we’ll go there anyway.

Based on the 2008-2014 time frame, we might “expect” 500 tornado warnings and 170 tornadoes once March has concluded. A longer-term average from NCDC says we should get about 144 tornadoes during the first three months of the year.

If this year’s 66 warnings and ~36 tornadoes through the end of March were hard to contextualize, that should at least help.

Even though this year is running about half as potent as the least potent in the “since 2008” sample, it’s hard to necessarily draw grand conclusions about the end-state of this tornado year. We’re just now entering into the typical peak months of April-June. This three month period is when over half of all tornadoes have happened historically.

Many will point to a season like 2010, which started quite slow and still ended up fairly significant. And as noted, 2012 started off big and ended fairly mediocre as far as overall numbers.

Again, a very small sample of the total modern tornado record, more for visualization of the current tornado drought rather than extrapolation for the rest of the year or beyond. Even expanding a comparison of first quarter of the year to total tornadoes in the full modern record doesn’t tell too much of a story. Some quiet years stay quiet, others go big, and others go average.

It’s wait and see time. Given that some of the highest human-toll tornado events have occurred early in the “season,” it won’t be such a bad thing if we stay quiet a bit longer.

Note: There’s a slight discrepancy between the 2015 tornado report numbers here and raw SPC numbers. I am using their filtered version (as it appears they do), but also noted that the Gig Harbor, Wa. tornado of Jan 18 appears to have been counted twice. Reports indicate this was one tornado. Given the numbers are preliminary overall, we should use them as a general guide and not a hard and final number anyway.

We’ve highlighted in the past how tornado reports are not necessarily all tornadoes, though the filtered version is often fairly close these days. Lacking a running verified list (NWS needs to do this!), seasonal counts are difficult to pin down accurately as the season is ongoing. Additionally, tornado warnings were issued on March 31. If any confirmed reports come from that or the other end of month event we will note here.