Tornados count relationship to hurricanes in NC

[downeastnc]

In the main Atlantic hurricane thread on the main forum I had seen several years thrown out there as analogs for this years cane season......two of the more common ones were 1996 and 1999 which if you lived in NC are years we got smacked about quite a bit.

So the other day Shaggy looked up those years and searched for severe weather to see if they had active severe weather springs or not and to see what those years had.

Interestingly enough

4-15-96 had a tornado outbreak in NC



then strangely enough 4-15-99 also had a small outbreak



then of course we all know what happened 4-16-2011




So while I dont really hold to much faith in analogs I was surprised to see this and overall both 96 and 99 were very good severe years with lots of springtime storm activity all across the SE and North Carolina. I will however be a believer if NC gets hit by several hurricanes this year lol......

[shaggy]

Heres my best shot at running some stats off the NCDC stats page. Any of you guys that are better with statistics than I am please feel free to correct me if I have made an error somewhere

ok here are the numbers using the NCDC storm event pages stats. I used Jan 1st to June 30th as my sample dates.

Of the years we have seen landfalling tropical storms and hurricanes in NC we saw 8 years since 1984. Those years are

1984- Diana

1996- Bertha/Fran

1998-Bonnie

1999- Dennis/Floyd

2003-Isabel

2004-Charley

2006-Ernesto

2008-Hanna

In those 8 years we had a total of 232 tornadoes with an avg of 29 a year.

In the other 18 years of no tropical landfalls we have a total of 174 tornadoes and an avg of only 9.6 a year. This number is thrown off by 2 of those years that saw high tornado counts in 1989 with 24 and 2009 with 31. So those 2 years account for 55 out of the 174 total. 2009 only had 8 named tropical systems all year as well.

4 out of the 8 years with tropical landfalls had years with 30+ plus tornadoes.

IMO there seems to be a pattern of more tropical activity in general for NC when we have an active spring with lots of tornadoes.

[k***]

Heres my best shot at running some stats off the NCDC stats page. Any of you guys that are better with statistics than I am please feel free to correct me if I have made an error somewhere

ok here are the numbers using the NCDC storm event pages stats. I used Jan 1st to June 30th as my sample dates.

Of the years we have seen landfalling tropical storms and hurricanes in NC we saw 8 years since 1984. Those years are

1984- Diana

1996- Bertha/Fran

1998-Bonnie

1999- Dennis/Floyd

2003-Isabel

2004-Charley

2006-Ernesto

2008-Hanna

In those 8 years we had a total of 232 tornadoes with an avg of 29 a year.

In the other 18 years of no tropical landfalls we have a total of 174 tornadoes and an avg of only 9.6 a year. This number is thrown off by 2 of those years that saw high tornado counts in 1989 with 24 and 2009 with 31. So those 2 years account for 55 out of the 174 total. 2009 only had 8 named tropical systems all year as well.

4 out of the 8 years with tropical landfalls had years with 30+ plus tornadoes.

IMO there seems to be a pattern of more tropical activity in general for NC when we have an active spring with lots of tornadoes.

That's not the greatest sample size but some interesting statistics nonetheless. Seems like the similar patterns (incoming troughs) produce tornadoes and NC landfalls. Years with big ridging likewise would not be great for tornado outbreaks and would suppress TC tracks to the south and into FL/GOM.

[shaggy]

That's not the greatest sample size but some interesting statistics nonetheless. Seems like the similar patterns (incoming troughs) produce tornadoes and NC landfalls. Years with big ridging likewise would not be great for tornado outbreaks and would suppress TC tracks to the south and into FL/GOM.

Well I was afraid of going outside of that sample size because of the possibility that alot of tornadoes in the 50's-60's and 70's may have gone unreported or were reported as straightline wind damage. With the increase in basic observations of the general public and dopplar radars the tornado data is much more reliable over the last 25 years.

The numbers are interesting and I guess we will see what happens come hurricane season but just found it very interesting. We are over 30 tornadoes this year already so this will be a good year to see if this possible correlation holds up.

[weatherman566]

We are going to have a hurricane impact the United States this year. It's very likely in my opinion. Based on the pattern, you can also use 2008 as a great analog. We had a very active severe weather season across the Southeast (Remember March 15?). We had cold air that didn't want to leave across the northern portions of the United States. Also, we are in a fading La Nina. In my opinion, our hurricane seasons are the most active when La Nina is dying or if we are in neutral territory. (No La Nina or El Nino)

I'm thinking a storm similar to Ike. Just my thoughts. 2011 will have a bigger impact this year than the previous years. Not as much activity as last year, but more impacts. Plus, the Gulf is unusally warm for this time of year. See if I'm right!

[shaggy]

It has been brought to my attention that while I focused on NC landfalls only the SE did in fact sustain a hit in 1989 which had an elevated tornado number. Hugo was in that year and struck SC instead of recurving into NC.

[shaggy]

A little more breakdown by the numbers:

Of the years where 30+ tornadoes were confirmed we have

1984 with 34 T's and Hurricane Diana

1996 with 31 T's and Bertha/Fran

1998 with 54 T's and Bonnie

2008 with 45 T's and Ernesto

2009 with 31 T's No storm

Thats 80% of those years with a subsequent landfall. The only year that didn't 2009 was a down year for the tropics with a well below avg of just 8 named storms.

Next group of numbers is 20-30 Tornadoes and that was one year only

1989 with 24 T's Hurricane Hugo

Next group 14-20 tornadoes

1991 with 17 T's No landfall(close call with bob)

1999 with 14 T's Dennis/Floyd

2000 with 19 T's No storm

2003 with 17 T's Isabel

2004 with 19 T's Charley

2006 with 18 T's Hanna

So thats 4 out of 6 years with landfalling storms.

We are currently sitting in the over 30 T's range for the year so that puts us in the highest % for POSSIBLE tropical action this year.

[downeastnc]

A little more breakdown by the numbers:

Of the years where 30+ tornadoes were confirmed we have

1984 with 34 T's and Hurricane Diana

1996 with 31 T's and Bertha/Fran

1998 with 54 T's and Bonnie

2008 with 45 T's and Ernesto

2009 with 31 T's No storm

Thats 80% of those years with a subsequent landfall. The only year that didn't 2009 was a down year for the tropics with a well below avg of just 8 named storms.

Next group of numbers is 20-30 Tornadoes and that was one year only

1989 with 24 T's Hurricane Hugo

Next group 14-20 tornadoes

1991 with 17 T's No landfall(close call with bob)

1999 with 14 T's Dennis/Floyd

2000 with 19 T's No storm

2003 with 17 T's Isabel

2004 with 19 T's Charley

2006 with 18 T's Hanna

So thats 4 out of 6 years with landfalling storms.

We are currently sitting in the over 30 T's range for the year so that puts us in the highest % for POSSIBLE tropical action this year.

Cant say we didnt warn ya........

[NavarreDon]

Cant say we didnt warn ya........

Nice find & impressive work. Props to you and Shaggy

[shaggy]

Nice find & impressive work. Props to you and Shaggy

Thanks. It started out as just a casual conversation between me and downeast(we're brothers) and it just kinda went from there. As we found more interesting numbers the more we looked into it.

This now makes 5 out of 6 years with 30+ tornadoes in the spring with subsequent landfalling tropical systems.

[WidreMann]

Thanks. It started out as just a casual conversation between me and downeast(we're brothers) and it just kinda went from there. As we found more interesting numbers the more we looked into it.

This now makes 5 out of 6 years with 30+ tornadoes in the spring with subsequent landfalling tropical systems.

You need more than that. Years with landfalling tropical systems that had no spring tornado outbreak? What constitutes an outbreak? What area does the outbreak occur in and what area does the TC have to make landfall? All you've done so far is not very scientific at all.

[shaggy]

You need more than that. Years with landfalling tropical systems that had no spring tornado outbreak? What constitutes an outbreak? What area does the outbreak occur in and what area does the TC have to make landfall? All you've done so far is not very scientific at all.

I went from Jan 1st through June 30th of all the years I looked at. I stopped at June 30th to prevent any contamination from tropical systems making landfall. I searched NCDC for my info. Once we get back into the 70's tornado reports drop considerably and many were probably not reported like they have been in the last 30 years or so.

There were 17 years without a landfalling tropical system. The average tornado count between Jan 1st and June 30th for those non-landfalling years is 8.8 tornado confirmations(doesn't mean there weren't more that went unreported). Of the landfalling years which equaled 9 years the average number of tornado confirmations was 28.4 for NC. If you add this year to the numbers we have 65 tornadoes on the NCDC site http://www4.ncdc.noaa.gov/cgi-win/wwcgi.dll?wwevent~storms that I am using and that increases the average to 32.1 for years with landfalling tropical systems.

Years that have had landfalls 32.1 average

years without 8.8.

Not scientific but the numbers speak pretty clearly......feel free to provide me evidence that my numbers are wrong.

[CAD_Wedge_NC]

I went from Jan 1st through June 30th of all the years I looked at. I stopped at June 30th to prevent any contamination from tropical systems making landfall. I searched NCDC for my info. Once we get back into the 70's tornado reports drop considerably and many were probably not reported like they have been in the last 30 years or so.

There were 17 years without a landfalling tropical system. The average tornado count between Jan 1st and June 30th for those non-landfalling years is 8.8 tornado confirmations(doesn't mean there weren't more that went unreported). Of the landfalling years which equaled 9 years the average number of tornado confirmations was 28.4 for NC. If you add this year to the numbers we have 65 tornadoes on the NCDC site http://www4.ncdc.noa...?wwevent~storms that I am using and that increases the average to 32.1 for years with landfalling tropical systems.

Years that have had landfalls 32.1 average

years without 8.8.

Not scientific but the numbers speak pretty clearly......feel free to provide me evidence that my numbers are wrong.

Nice research Shaggy/Downeast....... Don't worry about Widreman, he gives everyone a hard time. We overlook him as much as possible. He's still mad because the trees in his yard caught all the snow last winter.

[WidreMann]

Nice research Shaggy/Downeast....... Don't worry about Widreman, he gives everyone a hard time. We overlook him as much as possible. He's still mad because the trees in his yard caught all the snow last winter.

I think asking for more than two lucky analogs was a fair request. Shaggy provided an adequate response to my request.

[Sunny and Warm]

There is some truth to these analogs. When I lived in PA, April/May troughs often led to summer ridging. In fact, you could predict summer heat to be above/below average by what spring brought. Correlation is pretty high.

[Brick Tamland]

So where do earthquakes fit in the picture?

[Juliancolton]

I'm thinking a storm similar to Ike. Just my thoughts. 2011 will have a bigger impact this year than the previous years. Not as much activity as last year, but more impacts. Plus, the Gulf is unusally warm for this time of year. See if I'm right!

How can you have any idea what the storm will be like?

[downeastnc]

Going to bump this thread to make it easier to keep track of how many tornados we have this year, since we do pretty good about listing confirmed ones in threads I was hoping folks would also include any confirmed tornados this year in this thread. The numbers in 2011 pointed to us getting hit and we had Irene , last year we barely had any tornados and obviously no hits from last years putrid TC season.

 

This year we have had 3 confirmed that I know of all yesterday 2 in Roberson and 1 in Wayne, there was also the Beaufort hit but I checked and it was Dec 26th so it wont count on this years cycle....if there was another one I missed this year let me know here thanks.

[downeastnc]

A little more breakdown by the numbers:

Of the years where 30+ tornadoes were confirmed we have

1984 with 34 T's and Hurricane Diana

1996 with 31 T's and Bertha/Fran

1998 with 54 T's and Bonnie

2008 with 45 T's and Ernesto

2009 with 31 T's No storm

Thats 80% of those years with a subsequent landfall. The only year that didn't 2009 was a down year for the tropics with a well below avg of just 8 named storms.

Next group of numbers is 20-30 Tornadoes and that was one year only

1989 with 24 T's Hurricane Hugo

Next group 14-20 tornadoes

1991 with 17 T's No landfall(close call with bob)

1999 with 14 T's Dennis/Floyd

2000 with 19 T's No storm

2003 with 17 T's Isabel

2004 with 19 T's Charley

2006 with 18 T's Hanna

So thats 4 out of 6 years with landfalling storms.

We are currently sitting in the over 30 T's range for the year so that puts us in the highest % for POSSIBLE tropical action this year.

 

 

Since we are officially at the cut off point we used to make these list I thought I would give a update, based on the numbers out there the number of tornados so far is in the mid to upper 20's and possibly right at 30 but a lot of these are unconfirmed reports of tornados etc. so a firm working number is hard to find ATM.

 

That said with the above numbers of 25-30 tornados so far this year means we fall into the above average chance of seeing a landfalling TC in NC. If we have had 30 (unofficially we have had 28 ) then 5 out of 6 years with that many ended with a landfalling TC in NC......however and interestingly the one year we had 30+ tornados and no landfall we were in a EL Nino which we are apparently in or heading into now......

 

If you take all years that had a landfalling TC in NC and average all of them the average number of tornados in a year with a landfall is 28 which is again right about where we are for the year. So again all indicators strongly suggest a higher than normal chance of a landfalling TC in NC this year.....with the El Nino being the only caveat.

 

the last few years have proven pretty reliable since this thread first started

 

2011 had a insanely high number of tornados well over 30 and we had Irene

 

2012 had 17 and Beryl was technically a depression then a post tropical system with winds of 40mph over the NC coast so that's iffy and we haven't been counting depressions and haven't really considered post/sub/extra tropical systems and how they factor in especially since the criteria used to determine these things has evolved and gotten more precise over the last 20 years or so.

 

2013 we had 8 tornados and that matches the average of tornados we have for years without landfalls so that is exactly what we would have expected last year.

[downeastnc]

Since we are officially at the cut off point we used to make these list I thought I would give a update, based on the numbers out there the number of tornados so far is in the mid to upper 20's and possibly right at 30 but a lot of these are unconfirmed reports of tornados etc. so a firm working number is hard to find ATM.

 

That said with the above numbers of 25-30 tornados so far this year means we fall into the above average chance of seeing a landfalling TC in NC. If we have had 30 (unofficially we have had 28 ) then 5 out of 6 years with that many ended with a landfalling TC in NC......however and interestingly the one year we had 30+ tornados and no landfall we were in a EL Nino which we are apparently in or heading into now......

 

If you take all years that had a landfalling TC in NC and average all of them the average number of tornados in a year with a landfall is 28 which is again right about where we are for the year. So again all indicators strongly suggest a higher than normal chance of a landfalling TC in NC this year.....with the El Nino being the only caveat.

 

the last few years have proven pretty reliable since this thread first started

 

2011 had a insanely high number of tornados well over 30 and we had Irene

 

2012 had 17 and Beryl was technically a depression then a post tropical system with winds of 40mph over the NC coast so that's iffy and we haven't been counting depressions and haven't really considered post/sub/extra tropical systems and how they factor in especially since the criteria used to determine these things has evolved and gotten more precise over the last 20 years or so.

 

2013 we had 8 tornados and that matches the average of tornados we have for years without landfalls so that is exactly what we would have expected last year.

 

The number of tornados we had this year from Jan 1 to June 1st indicated that we would be very likely to have a landfalling TC this season in NC. The total number of tornados in 2014 is still not confirmed but several tornados I know occurred  are not listed as official but the total was around 30 which would put 2014 in the top tier so after last night we have had a landfalling TC in 6 of the 7 years we have had 30 or more tornados by June 1st....

[shaggy]

With last weeks active storms and several tornados does anyone have a confirmed tornado count so far this year? We should be somewhere around 10-13 I think if I remember correctly.

[LithiaWx]

You guys can't really believe this stuff?  Can you?

 

correlation does not equal causation

[downeastnc]

2 hours ago, LithiaWx said:

You guys can't really believe this stuff?  Can you?

 

correlation does not equal causation

Believe what?  We just noticed a strange pattern where it seems that the years that have extremely active severe weather in NC also tends to be the years we have landfalling TC in NC, while years with quiet severe weather seasons tend to not have landfalling TC's. Its just a interesting and fun observation and every year around this time we try to see where the numbers are. 

[LithiaWx]

3 hours ago, downeastnc said:

Believe what?  We just noticed a strange pattern where it seems that the years that have extremely active severe weather in NC also tends to be the years we have landfalling TC in NC, while years with quiet severe weather seasons tend to not have landfalling TC's. Its just a interesting and fun observation and every year around this time we try to see where the numbers are. 

The theory is right up there with earthquake and hurricane correlation.   JMO but sometimes we look too hard trying to find patterns that are random. 

[snowlover91]

30 minutes ago, LithiaWx said:

The theory is right up there with earthquake and hurricane correlation.   JMO but sometimes we look too hard trying to find patterns that are random. 

 

Its a far more valid conclusion with statistical data to back it up. The atmosphere tends to go in patterns and cycles, this is a scientific fact. It's reasonable to conclude that when statistics indicate a certain pattern produces certain outcomes it's worth looking in to. 

After all, this is how seasonal forecasting is done even though this is in its infancy. Large scale patterns like El Niño's generally correlate with wetter patterns in this area and a better chance for cold weather. There are various other factors that affect it too but that's just one example. What Ron posted is an interesting correlation that is worth looking further into. He actually took the time to do research and back up his statements with statistical analysis, if you're going to criticize it you should come up with some facts to indicate otherwise. Just my 2 cents. 

[LithiaWx]

25 minutes ago, snowlover91 said:

 

Its a far more valid conclusion with statistical data to back it up. The atmosphere tends to go in patterns and cycles, this is a scientific fact. It's reasonable to conclude that when statistics indicate a certain pattern produces certain outcomes it's worth looking in to. 

After all, this is how seasonal forecasting is done even though this is in its infancy. Large scale patterns like El Niño's generally correlate with wetter patterns in this area and a better chance for cold weather. There are various other factors that affect it too but that's just one example. What Ron posted is an interesting correlation that is worth looking further into. He actually took the time to do research and back up his statements with statistical analysis, if you're going to criticize it you should come up with some facts to indicate otherwise. Just my 2 cents. 

It was a good post but it's up to him to prove the theory.  I obviously don't give it much credit.  There are too many variables which can be framed to fit the limited data.

 

[snowlover91]

29 minutes ago, LithiaWx said:

It was a good post but it's up to him to prove the theory.  I obviously don't give it much credit.  There are too many variables which can be framed to fit the limited data.

 

I don't think he was trying to "prove" anything but rather show an interesting correlation that can be useful if further data continues to corroborate it. If you haven't read the other posts by Steve and Ron you should. It sounds like you read the first post in the thread and then wrote it off without reading the additional info/research provided. 

[frazdaddy]

On 5/27/2017 at 5:38 PM, snowlover91 said:

I don't think he was trying to "prove" anything but rather show an interesting correlation that can be useful if further data continues to corroborate it. If you haven't read the other posts by Steve and Ron you should. It sounds like you read the first post in the thread and then wrote it off without reading the additional info/research provided. 

GOOD POST.

[shaggy]

So I was sitting here at work bored freezing my butt off and went to the NCDC to research the years since Irene in 2011. So here are the reported tornadoes and subsequent tropical system activity.

2012 tornadoes 12 landfalls none

2013 tornadoes 5 landfalls none

2014 tornadoes 31 landfalls Arthur

2015 tornadoes 8 landfall Ana

2016 tornadoes 12 landfall Mathew along SC coast

2017 19 landfalls none

This now makes 6 out of 7 years with 30+ tornadoes with a landfall later in the year.

So averaging out the years with landfalls and the average tornado count is 34.8 and without landfalls is at 10.

So 6 years later and the data and unscientific results are holding true.

[shaggy]

So figured I would revisit this thread since it's been active so far this spring. Last year was the exception to our research. I only saw 6 confirmed tornados for last year and we had florence. Florence was an anomaly all of her ow  though.