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Large tornadoes in 2017.

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2017 got off to a quick start for the tornado outbreak tracker. An outbreak hit on the second day of the new year and one of the largest winter tornado events on record struck in late January.

Since that time, additional large outbreaks struck in each month through June. After tending to the active side for much of the year, we have settled into a close-to-average range while awaiting any tropical or second season activity. So far, 11 outbreaks can make our list.
[Tornadoes of 2017 - Wikipedia]
As in the past, we'll continue to use a 20 confirmed tornado count as the baseline for this outbreak tracker. While there is plenty of argument about what constitutes an outbreak, there is little doubt some of the low numbers accepted in the past are too low for today's reporting environment. We feel that using 20 as a base removes most questions as to an event's legitimacy as notable in most years.

Posted: January 5, 2017. Last updated: August 18, 2017.

Large tornado outbreaks of 2017
Events with at least 20 confirmed tornadoes
(A) January 2, 2017 | 36 confirmed tornadoes, 43 reports, 37 warnings, 4 watches
January 2 SPC event page

A typical cold-season tornado event, low pressure moved across parts of the South spawning severe weather and tornadoes. Many of the tornadoes came from line segments of storms known as quasi-linear convective systems. A larger convective system also created numerous wind damage reports, and in Alabama four people died from straight line winds.

(B) January 21-23, 2017 | 81 confirmed tornadoes, 112 reports, 198 warnings, 14 watches
Jan. 20 SPC event page | Jan. 21 SPC event page | Jan. 22 SPC event page

This classic high-end severe weather pattern set up the deadliest few days of tornadoes in over a year. It was also among the largest tornado outbreaks on record during the winter. More people were killed in this series of tornado volleys than all of 2016. We also saw the first "High Risk" from the Storm Prediction Center since 2014, although it ended up not being the biggest tornado day of the bunch.

A powerful late-winter jet stream overspread a warm and unstable air mass hanging out in much of the eastern half of the country, touching off a major early-season severe weather outbreak. Tornadoes were focused across parts of the Midwest and upper Mid-South. Several high-end tornadoes impacted parts of Illinois, Missouri, and Indiana. Long-track tornadoes across southern Missouri, Illinois, and Indiana were somewhat reminiscent of the great Tri-State event of 1925.

(D) Mar. 6-7, 2017 | 60 confirmed tornadoes, 89 reports, 90 warnings, 6 watches
Mar. 6 SPC event page

Another in a late-winter and early-spring volley of storm systems, this one was the farthest west outbreak so far this year. While many of the tornadoes were QLCS-type, spinning up within lines and broken lines, several supercells dropped tornadoes as well. The Kansas City area was particularly hard hit as an EF3 struck east of town. Fortunately, no one was killed despite relatively high impact.

The South took on yet another outbreak, and sadly more tornado deaths occurred in this event. At least three people were confirmed killed over the two days. The first day of this outbreak included an infrequent "high risk" from the Storm Prediction Center, the second such issuance this year. Interestingly enough, no tornadoes of EF3+ strength have been confirmed, which is unusual for a "high risk" event.

The wait wasn't long for another high risk. Following a several-year lull without, the third of the year came along. Much like the first, parts of the southeast were ground zero for this event. This one had the look of a biggy, and it was, even though many will tell you it was not. A low-amplitude trough with speed max pushing into the risk area at just the right time for ugly weather. As with many such days, storm mode threw a wrench or two into plans. Despite what chasers might say, days like this not reaching maximum potential is always a good thing.

A cap to an active month, this was a fairly classic system that featured an upper level low crossing the four corners, and significant severe weather across the eastern Plains into the South and Midwest. Also, a blizzard in the High Plains. Linear convective systems with embedded supercells were the dominant storm type, as has been the case in much of 2017. This event was unfortunately the cause of a number of deaths in several different tornadoes.

An overperformer, and the start of kind of a weird peak season that favored places east of normal. Much of the day featured a marginal risk from the Storm Prediction Center as a shortwave trough over the Mississippi Valley prepared to enter into a longwave trough focused over the Carolinas. A number of tornadoes occurred on a QLCS system over the southern part of the region early in the day. As the shortwave rotated through the region, a warm front in the Carolinas and Virginia helped pop some more supercells and tornadoes into the night.

This was perhaps the most classic multi-day chase event of the season as things lined up for a big Plains day followed by more tornadoes as the upper low moved out across the region the day after. May 18 featured yet another high risk, this time over parts of southern Kansas and northern Oklahoma. Like most high risk days, there were plenty of tornadoes, and lots of fast moving storms, storm mergers and difficult chasing. Tornadoes hit Kansas again the day after when the upper low rolled by, and additional activity was reported east along the cold front.

(J) May 24, 2017 | 23 confirmed tornadoes, 37 reports, 54 warnings, 5 watches
SPC event page

This one just inched into our count here, and it impacted a region that has seen plenty of tornado events during 2017. Another large upper level trough slowly swinging east was the culprit. Perhaps the most notable aspect of this event was that it started so far east. It came near the tail of one of several very quiet stretches for tornado alley during peak season.

(K) June 28, 2017 | 24 confirmed tornadoes, 33 reports, 43 warnings, 4 watches
SPC event page

Once we get out of the peak of the peak of the season, getting big outbreaks can be tough. Even by June, some you might expect on this list - like the one in Wyoming and the surrounding high plains that dropped just shy of 20 tornadoes - are not there. "Subtle and almost anywhere" is the tale of this late in the season many years. With low pressure spinning over Minnesota, clusters of supercells developed in places like Iowa, dropping a number of photogenic tornadoes on somewhat of a low-key day.

The top 5 events based on confirmed tornadoes

#1: January 21-23, 81 tornadoes (B)
#2: May 18-20, 76 tornadoes (I)
#3: February 28-March 1, 70 tornadoes (C)
#4: March 6-7, 60 tornadoes (D)
#5: April 2-3, 59 tornadoes (E)

Methodology/Sourcing

For an outbreak to be continuous over multiple days, there must be no breaks greater than 12 hours. In some eyes this may constitute separate outbreaks, but we do it in attempt to simplify the discussion and to attempt to capture a system crossing the United States in its entirety as one outbreak when possible. Although we are presenting confirmed tornadoes, data is preliminary and subject to change. This is particularly the case when the most recent event is less than a week or two in the past.

We have tried to do this project over several years now. It is one that we are very interested in. It also happens to be quite time consuming for a small team that also has day jobs. While discussing how to move forward during our update over this summer, we have concluded that Wikipedia is a great source we should not be overlooking. We will continue to independently verify data we use, but the primary source for a current year (prior to SPC release of track information) will be that website.
Mitch Feiler contributed to this post.
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The largest tornado outbreaks of 2017 - U.S. Tornadoes

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2017 got off to a quick start for the tornado outbreak tracker. An outbreak hit on the second day of the new year and one of the largest winter tornado events on record struck in late January. Since that time, additional large outbreaks struck in each month through June.

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Hurricane Harvey happened for several days in 2017.

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Video

Satellite images show the scale of flooding in towns outside of Houston. Satellite images ©2017 DigitalGlobe.

Video

Some families hit hard by Tropical Storm Harvey are choosing to stay in their flooded homes. We take you along a rescue mission in a community in southeast Houston, where some also choose to leave.

Survivors face hurdles of their own, with help likely to be slow in coming. Managing the shelters that are housing tens of thousands of them remains " the biggest battle that we have right now," Brock Long, the administrator of the Federal Emergency Management Agency, said on Thursday. Rich and poor alike have had their homes and lives upended.

There were many positive stories, too. A huge volunteer effort operated with little official guidance. A businessman turned his mattress store into a safe haven. And the women and cat in a viral photo of a flooded nursing home are safe. The Houston Independent School District also said that all students will receive three free meals a day for the school year.

While it has been called a " 500-year flood," that term may be misleading: A similar storm may not be as far off as you might think.

Video

Homes and shelters were flooded and the largest oil refinery in the U.S. was shut down after heavy rains flooded Port Arthur, east of Houston, overnight Tuesday. Credit Credit... Beulah Johnson, via Associated Press

* The Hurricane Harvey Relief Fundwas established by Mayor Sylvester Turner of Houston and is administered by the Greater Houston Community Foundation.

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Hurricane Harvey: The Devastation and What Comes Next

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Survivors face hurdles of their own, with help likely to be slow in coming. Managing the shelters that are housing tens of thousands of them remains " the biggest battle that we have right now," Brock Long, the administrator of the Federal Emergency Management Agency, said on Thursday.

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Hurricane Irma happened for several days in 2017.

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The Meteor Showers happened in 2017.

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All year long as Earth revolves around the sun, it passes through streams of cosmic debris. The resulting meteor showers can light up night skies from dusk to dawn, and if you're lucky you might be able to catch one.

If you spot a meteor shower, what you're really seeing is the leftovers of icy comets crashing into Earth's atmosphere. Comets are sort of like dirty snowballs: As they travel through the solar system, they leave behind a dusty trail of rocks and ice that lingers in space long after they leave. When Earth passes through these cascades of comet waste, the bits of debris - which can be as small as grains of sand - pierce the sky at such speeds that they burst, creating a celestial fireworks display.

A general rule of thumb with meteor showers: You are never watching the Earth cross into remnants from a comet's most recent orbit. Instead, the burning bits come from the previous pass. For example, during the Perseid meteor shower you are seeing meteors ejected from when its parent comet, Comet Swift-Tuttle, visited in 1862 or earlier, not from its most recent pass in 1992.

That's because it takes time for debris from a comet's orbit to drift into a position where it intersects with Earth's orbit, according to Bill Cooke, an astronomer with NASA's Meteoroid Environment Office, who spoke to The New York Times last year.

The name attached to a meteor shower is usually tied to the constellation in the sky from which they seem to originate, known as their radiant. For instance, the Orionid meteor shower can be found in the sky when stargazers have a good view of the Orion constellation.

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All year long as Earth revolves around the sun, it passes through streams of cosmic debris. The resulting meteor showers can light up night skies from dusk to dawn, and if you're lucky you might be able to catch one. If you spot a meteor shower, what you're really seeing is the leftovers of icy comets crashing into Earth's atmosphere.

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The earthquake happened on September 19, 2017.

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Mexico Earthquake Kills Hundreds, Trapping Many Under Rubble (Published 2017)

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In Mexico City, where a school collapsed, ordinary citizens used their bare hands to try to free the students trapped in the rubble.

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The Solar Eclipse happened on August 21st 2017.

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On August 21, 2017, the shadow of the Moon will sweep across the U.S. landscape, transforming day to twilight. In the surreal gloaming of an eclipse, the temperature drops, birds go silent, crickets begin to chirp, and blossoms start to close. As this scene plays out across a 70-mile wide path of totality from coast to coast, a continent-spanning wave of instruments -- ranging from home-made pinhole cameras and certified eclipse safety glasses to the most sophisticated telescopes in operation today - will be trained on the Eclipse Across America.

Just before totality, a point of glistening sunlight is visible making the moon look like a diamond ring. Then as that drop of sunlight shines through rugged valleys on the Moon's limb, tiny points of light called "Baily's Beads" appear like a string of beads around the vanishing edge of the sun. But best of all are the pearly white streamers that emanate all around the dark disk at totality.

Scientists eagerly anticipate this eclipse for the unique science opportunities it provides.

Alex Young, NASA's Associate Director for Heliophysics at the Goddard Space Flight Center in Greenbelt, Maryland, says, "This will be the first total eclipse to span the U.S. since 1918, and scientific instruments have come a long way."

The event presents a perfect opportunity to shed light on phenomena such as solar flares and coronal mass ejections, or CMEs -- billion-ton clouds of magnetized plasma ejected from the sun. To learn about their dynamics, researchers must study a region of the sun that reveals itself during an eclipse-the corona.

"Solar telescopes can create artificial eclipses using disks called coronagraphs," explains Young. "Unfortunately, man-made coronagraphs also block the sun's inner corona where CME eruptions originate."

Fortunately, during a total eclipse of the sun, the Moon makes a better coronagraph. At totality, the sun's inner corona appears in clear detail.

Totality lasts mere minutes at any one location, but the Citizen Citizen CATE Experiment will be positioning 68 identical telescopes across the country in the path of totality. The combined network will capture 93 minutes of images and will show changes in the solar atmosphere.

Matt Penn, Astronomer at the National Solar Observatory in Tucson, Arizona says, "The telescopes will be operated by a variety of volunteers, ranging from middle school students to retired scientists, and everyone in between."

Meanwhile, NASA planes will photograph the Sun, and a cadre of balloons will be floating near the edge of space to observe the eclipse. You can watch too - live from the balloons on August 21 at eclipse.stream.live.

"The terrain and weather are quite varied across the U.S., and the Moon's shadow will briefly change the climate in each locale, sometimes with drastic drops in temperature within seconds to minutes."

Young reminds everyone to be safe. Solar filters such as eclipse glasses are necessary to look at the sun directly. If you're in the narrow path of totality, you can safely remove your solar filter when the moon completely covers the sun. However when the Moon moves off the center of the solar disk-even a little-the sun's blinding surface reappears and you should once again use your solar filter. NASA has a whole web page devoted to safety tips: eclipse2017.nasa.gov/safety

Many people don't know that the Moon's orbit is slowly spiraling outward due to tidal forces. In about 600 million years the Moon will appear too small in the sky to fully cover the sun. Every solar eclipse is counting down to the last one.

Young says, "We live in a fortunate time."

For NASA's live coverage of the eclipse go to www.nasa.gov/eclipselive

For total coverage of NASA science, visit science.nasa.gov

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On August 21, 2017, the shadow of the Moon will sweep across the U.S. landscape, transforming day to twilight. In the surreal gloaming of an eclipse, the temperature drops, birds go silent, crickets begin to chirp, and blossoms start to close.