Lack Of April Tornadoes This Year

April is winding down and so far there have been no reports of tornadoes in the state.  If this holds up, it would break our string of 3 consecutive months with tornadoes and leave 2012 tied with 1976 as the only years on record with tornadoes in January, February and March. 

Historic April 25-28, 2011 Tornado Outbreak

Who can forget the unbelievable tornado outbreak of April 25-28, 2011, which produced hundreds of tornadoes, took hundreds of lives and devastated many communities in southern and eastern states?  Indiana shares a small part of this massive outbreak with 3 confirmed tornadoes - two on the 26th and one on the 27th.

To read the storm surveys for these 3 tornadoes, click here 

April 25, 1961 Tornado

On April 25, 1961, at least one powerful F4 tornado swept across portions of east central Indiana.  Touching down in Shelby county a few miles north of Shelbyville, this tornado passed over I-74 with eyewitnesses reporting multiple vorticies.  The tornado destroyed barns and homes in Shelby and Rush counties.  Additional heavy damage occurred near the town of Boston where homes were destroyed.  The tornado eventually passed into Ohio.  Several people were injured but fortunately there were no fatalities.

This event may have actually been two separate tornadoes but it is not clear.


Source:

Thomas P. Grazulis, Significant Tornadoes 1680-1991 (Environmental Films, 1993).

April 20, 2004 "Surprise" Tornado Outbreak

Today is the eight year anniversary of the April 20, 2004 tornado outbreak.  It is hard to believe it has been that long.  Simply put, it remains one of the most poorly forecasted severe weather events I have ever seen.  Thankfully no lives were lost in Indiana but that was not the case in other areas.  You can view an excellent writeup on this event here

Also, be sure to check out the photo gallery, which contains several pictures from this event.

Map of Tornado Tracks

Remembering A Pair Of Significant April 19 Outbreaks

April 19, 1996 - 13 tornadoes

Map of Tornado Tracks

April 19, 2011 - 29 tornadoes

Map of Tornado Tracks

April Tornadoes By F/EF Scale Rating

1950-2010

April 3, 1974 Super Outbreak

Today is the anniversary of the 1974 Super Outbreak which impacted Indiana in a big way.  Click the link below to view the post from last year.

http://indianadoes.blogspot.com/2011/04/recalling-biggest-tornado-outbreak-on.html

2011 Year In Review

As we move toward the end of 2011, I thought it would be prudent to post a summary of this year's tornadoes.  Here it is month by month.


February:

6 tornadoes occurred, all of them on the last day of the month.  An EF2 tornado cut a 14 mile swath in Dubois county, injuring 1 person.  A separate EF2 struck portions of Gibson and Pike counties.


April:

This was a quiet month for tornadoes until the 19th.  29 tornadoes struck the state on the 19th and into the 20th, the second most in a single outbreak.  This event was followed up on the 23rd by an EF0 tornado in Jackson county.  Three additional tornadoes struck the state on the 26th and 27th, one of them an EF2 which had a 5 mile path through Warrick county.  There were 33 tornadoes in total during April, making it our second most active month on record.


May:

May followed a similar trend as April with a quiet early and middle part of the month.  Then an EF1 tornado in Jasper county kicked things off on May 22.  EF0 tornadoes struck Huntington and Ripley and Dearborn counties on the 23rd.  After a 1 day break, another significant outbreak happened on May 25.  This outbreak produced 22 tornadoes, including several EF2's and an EF3 in Lawrence county.  The Lawrence county tornado began east of Bedford and moved northeast for about 7 miles before lifting.  In all, there were 25 tornadoes in May.


June:

Like the preceding months, much of June was quiet.  The first tornado was a brief EF0 in Perry county on the 19th.  Another tornado struck Harrison county on the 22nd.  Two more tornadoes occurred during the early morning hours of the 26th, bringing the monthly total to 4. 


July:

Only 1 tornado happened in July, a brief EF0 in Newton county on the 23rd.


September:

After nearly 2 months without a tornado, an EF1 hit Jennings county early on the 26th.  An EF0 struck Elkhart county the following day. 


November:

An EF1 tornado touched down in Orange county on the 14th, the only tornado during November.  This was the last tornado of the year, bringing the 2011 total to 72.

Map Of April 19-20 Tornadoes

Three Additional Tornadoes Confirmed From Late April

Here is some info on the 3 newly added tornadoes from April 26 and April 27:

5 mile long EF2 in Warrick County:

At the initial damage point just southwest of Greenbrier, many trees were snapped or uprooted. As the tornado crossed Highway 61, it demolished a barn and tossed the debris about 50 to 75 yards. Another barn was damaged, and numerous large trees were uprooted and snapped. Several homes suffered roof damage from both the wind and from trees or large branches falling on them. Three telephone poles were snapped on Highway 61. Parts of the damage path were over inaccessible, roadless coal mine property. Peak winds were estimated near 120 mph. The average path width was 300 yards.

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1 mile long EF1 in Pike County:

The tornado began on Indiana Route 61 just south of Spurgeon. It travelled northeast across the eastern outskirts of Spurgeon. Numerous trees were snapped at the base. Several trees were uprooted. Several homes received minor roof damage. A barn was damaged, with debris carried a couple hundred yards. A small building was destroyed. Severe straight-line winds caused other damage throughout the town of Spurgeon. Peak winds were estimated near 105 mph. The average path width was 200 yards.

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Brief EF0 in Sullivan County:
An EF0 tornado briefly occurred near 621 E. Silver Street in Sullivan, Indiana. Damage was done to a home at this location. There was damage to a roof, one bathroom window was blown out, and a trampoline was blown over. Roof debris was spread out over the owner's lawn, with some shingles blown into a nearby tree and one large piece of ply wood from the roof was blown over the neighbor's house, up into a tree approximately 40 feet high.

Updated Information On April 19-20 Tornado Outbreak

First off, you can view the original summary of this event here.

The following changes were made to this outbreak:


-NWS North Webster changed their preliminary ruling of 2 tornadoes in Cass County to microbursts.

-NWS Paducah added a 5 mile long EF1 tornado from Warrick to Gibson counties.

-NWS Indianapolis added 2 tornadoes, a 3 mile long EF0 in Tippecanoe county and an 11 mile long EF1 in
Knox county.

-NWS Indianapolis extended the path of the Vermillion county tornado into Montgomery county for a total path length of 31 miles.  It was also downgraded from EF2 to EF1.

-NWS Indianapolis downgraded the Tippecanoe county EF2 to EF1.

-NWS Louisville added 2 tornadoes, a 2 mile long EF1 and a 3 mile long EF0 in Jefferson county.


There was a net gain of 3 tornadoes, increasing the total from 26 to 29 but still ranking this outbreak as having the second most on record.  Here are some updated stats:


Tornadoes by NWS area:

NWS Louisville:  19
NWS Indianapolis:  5
NWS North Webster:  3
NWS Paducah:  1
NWS Wilmington:  1


Tornadoes by intensity:

11 EF0
16 EF1
2 EF2

Most Frequent Tornado Days Since 1950

I have put together a list of the most frequent tornado days since 1950.  In other words, those calendar days which have produced at least one tornado most often.  Here are all of the days which have produced at least 5 times and I have also included the total number of tornadoes for each day.  Bold represents days which have had tornadoes in every decade with the exception of the current young decade.


April 20...5 days...22 tornadoes
April 28...5 days...5 tornadoes
May 14...5 days...10 tornadoes
May 18...5 days...9 tornadoes
May 25...5 days...10 tornadoes
May 26...7 days...13 tornadoes
May 27...7 days...10 tornadoes
May 28...6 days...11 tornadoes
May 30...7 days...35 tornadoes
May 31...6 days...10 tornadoes
June 4.....5 days...9 tornadoes
June 7.....5 days...13 tornadoes
June 8.....5 days...13 tornadoes
June 11...7 days...17 tornadoes
June 12...8 days...13 tornadoes
June 13...7 days...13 tornadoes
June 14...5 days...11 tornadoes
June 15...5 days...6 tornadoes
June 17...6 days...9 tornadoes
June 21...6 days...6 tornadoes
June 23...5 days...13 tornadoes
June 24...7 days...9 tornadoes
June 28...5 days...8 tornadoes
July 1......7 days...7 tornadoes
July 4......5 days...7 tornadoes
July 9......6 days...9 tornadoes


Interestingly, the day with the greatest number of tornadoes - June 2 - isn't on the list.  While only 3 June 2nds have produced tornadoes, a total of 46 tornadoes have occurred.

Violent Tornadoes And Recent Trends

F4/F5 tornadoes generate some of the strongest winds on the face of the earth and produce extreme damage.  Since 1950, Indiana has had over 2 dozen violent tornadoes which have occurred on 13 days.  3 days (4/11/1965, 4/3/1974, 6/2/1990) are responsible for a majority of the violent twisters, and these are the only days since 1950 to have at least 2 violent tornadoes.

Approximate F4/F5 tornado tracks, 1950-2010

April is a hot month with 5 out of the 13 violent tornado days occurring then. The median occurrence for a violent tornado is day #115 or April 25. Indeed, 2 violent tornadoes happened on or near this date, those being 4/25/61 and 4/26/94. Also, over half of the dates (7 out of 13) fall within the 60 day window of April 3 to June 2.

While we are past the median date for violent tornadoes, it does not mean that we should let our guard down until next year.  Violent tornadoes can happen at any time of year if the proper conditions come together.  It has been 13 years since our last violent tornado, which is the longest period without one since 1950.  While nobody can predict the date or location of the next one, it is only a matter of time until another one occurs.

NWS Confirms Tornado North Of Seymour

The National Weather Service office in Indianapolis has confirmed a tornado from the Saturday morning storms.  The tornado occurred in Jackson county just north of Seymour and had an intermittent path of approximately 4 miles.  For more information, see the page below:

http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=ind&storyid=67226&source=0

26 Tornadoes Confirmed In Tuesday-Wednesday Outbreak, Second Most On Record



Click For Larger Image

Wow, what an event.  With a total of 26 tornadoes, this is the biggest April outbreak on record and the second biggest in any month (37, 6/2/1990).  I had discussed the chance of tornadoes in a previous post but I was not expecting something like this, especially since the storms had transitioned into a more linear mode by the time they moved in from Illinois.  In a counterintuitive twist, with the instability/shear parameters being very favorable for tornadoes, perhaps the linear nature helped this outbreak be so prolific since it was unfavorable for long-lasting circulations/single tornadoes? 

Where should this outbreak rank among the all-timers?  Most of the tornadoes were relatively brief with no real standout, although total damage is still likely to run into the millions of dollars.  26 is certainly an impressive number, but despite being the second biggest outbreak on record, there were no violent tornadoes and only 4 EF2's.  Part of the problem in trying to compare modern outbreaks to those in past years is that more tornadoes are documented nowadays.  This event had more documented tornadoes than the 1965 Palm Sunday Outbreak and even the Super Outbreak, but I can't possibly claim that this one should rank among those.  Any attempt to rank outbreaks should employ a more complete approach than just looking at raw count, but even then you're at the mercy of imperfect data.  The lack of a violent, long track or high-impact tornado will make this event a little less memorable, but make no mistake, this was an impressive day that deserves to be recognized and remembered for many years to come.

A few notable aspects of this outbreak:

- 18 out of 26 tornadoes occurred in the 75 minute window between 11:15 PM and 12:30 AM

- Dubois county had 5 tornadoes, tied for the most in any Indiana county in one day since records have been kept.

- Anti-photogenic to the extreme - we're going on 4 days and I still haven't seen any pictures/video of a single tornado (Illinois footage doesn't count!).


We now stand at 30 tornadoes for the year, which is already above average.  With an active pattern continuing for the forseeable future, we will probably add to this total in the coming days.  Stay tuned...

21 Tornadoes Now Confirmed In Indiana From Tuesday-Wednesday Outbreak

The National Weather Service in Louisville has confirmed 7 additional tornadoes, bringing the state total to 21.  Here is the breakdown by area and intensity, subject to future modification as surveys are still ongoing.


NWS Louisville:  13
6 EF0, 5 EF1, 2 EF2

NWS North Webster:  5
2 EF0, 3 EF1

NWS Indianapolis:  2
1 EF1, 1 EF2

NWS Wilmington:  1
1 EF1

At Least 15 Tornadoes Confirmed From April 19-20 Severe Storms

National Weather Service personnel from North Webster, Indianapolis, Louisville KY and Wilmington OH have been surveying damage from Tuesday's storms and so far they have found 15 tornadoes.  The breakdown by area is as follows:

7 NWS Louisville
5 NWS North Webster
2 NWS Indianapolis
1 NWS Wilmington


This information is still preliminary and it is possible that additional tornadoes may be found.  Even if nothing else is found, this already goes down as one of the biggest April tornado outbreaks in state history in terms of raw count; it also surpasses a well-known outbreak that occurred exactly 15 years earlier on April 19-20, 1996.  It appears that many of the tornadoes were rain-wrapped and/or brief, and we are fortunate that most of them were of the EF0 or EF1 variety.  Still, this was a rather impressive event.

I will have more on this outbreak in the coming days.

April 17, 1922 Tornadoes

On April 17, 1922, multiple killer tornadoes struck Indiana.  One tornado nearly destroyed the tiny Warren county community of Hedrick before moving through Williamsport.  Another killer tornado struck Tipton and Madison counties, doing significant damage near Orestes.  Seventeen people died in all.

Here are the 500 mb and surface maps from that day.

April Nocturnal Tornadoes

With the upcoming significant storm and possible nighttime tornado threat, I decided to scan the records to see how many of our April tornadoes have occurred at night.  For purposes of this research, I defined the nocturnal period as the hours between 2100-0600.

Since 1950, there have been 228 April tornadoes in the state.  43 out of 228 occurred between 2100-0600 which comes out to 18.9%.  The 9 hour period makes up 37.5% of a day so it is clear that a majority of our tornadoes occur during daylight. 

The most recent April nocturnal tornado struck Decatur county in 2006.  The worst nocturnal tornado was the tornado that touched down near West Lafayette around midnight on April 26-27, 1994.  It took 3 lives and injured dozens more.     

I will have more on the upcoming storm system in a post later tonight...

April Tornadoes Per County Since 1950