A visit to the Swedish national weather service: SMHI

smhi norrköping

Yesterday I paid a visit to the Swedish national weather service: SMHI. It is something I have been wanting to do for quite some time since most of what I know about storms and weather is based on the weather situation in, and information from, USA.

Sweden is a very low on severe weather and I personally only experience about 2-3 thunderstorms per year. Tornadoes are extremely rare and I would assume all are EF0 from what I have seen from videos and photos. What I wanted to learn more about, while visiting SMHI was how rare tornadoes, supercells and other severe weather is in Sweden.

I got in contact with weather researcher Lisa Bengtsson who is a weather researcher in the field of the predictability in the atmosphere. Although she was not a specialist in the field of severe weather in Sweden she is one of the few at SMHI who actually had some experience with storm chasing. Lisa did her meteorology studies in Wisconsin in 2003 and spent a week chasing with the university weather club and was lucky enough to see two tornadoes. She was also lucky enough to find her Wisconsin-born husband, Joseph Sedlar, there. Joseph came along to Sweden and now also works at SMHI. I met up with both to discuss my favorite topic and to hear more about severe weather in Sweden.

lisa joe smhi
Lisa and Joe.

We talked a lot about storm chasing in general at first. Outside of their successful chase in Oklahoma Joseph had also done a few local chases in Wisconsin but none being successful enough to see a tornado. As you may know, Wisconsin is not a great chase area especially with all the trees, so chasing there is difficult and dangerous.

Severe weather in Sweden

We continued to talk about the severe weather in Sweden. It is a quite narrow subject since we don’t really get much severe weather in Sweden. Since severe weather in terms of supercells and tornadoes are so rare it is not a threat to consider here. Therefore there is no real need to quantify or report it, and there are no storm spotters or storm chasers either, so there is no data registered about it really. The only reports comes from social media and Swedes who spontaneously report tornadoes.

smhi

I am not sure though if using the word “tornado” here is suitable since the tornadoes (“tromb” in Swedish) we experience usually seems to be waterspouts coming ashore. At least those are the ones that gets reported or noted (land based, actual, tornadoes inland could remain unnoticed in remote areas). Since more people tend to live by the coasts, those are the ones that gets photographed and reported. Below is a beautiful example from Halmstad 2014 (not filmed by me):

 Here is another example which was actually north of Stockholm:

CAPE and shear in Sweden

Some of the reasons we do not get the same kind of severe weather as in the United States, or even continental Europe, is the lack of CAPE (instability) and the lack of moisture. The instability usually only builds up enough during long periods of High Pressure, which is when we usually get our thunderstorms (with August being the most prominent month).

We do get some moisture from the Baltic sea which does collide with the dry air from the mountains of Norway but the ingredients are just too weak to cause any major severe weather. Shear is, however, usually abundant and Sweden is close to the jet stream so we have some of the potential ingredients, but it is just not enough.

smhi radar stations

With global warming it seems plausible we would get more heat and moisture to Sweden so severe weather from thunderstorms may become more prominent in the future. One would imagine tornadoes being more common in Sweden already looking at Youtube but that is probably more likely due to more people having the possibility to film and share severe weather with their smart phones.

Weather threats in Sweden

Since, supercells and tornadoes does not pose a threat the weather is not usually observed in the mesoscale level so there are no real records of supercells either. The main threat from thunderstorms is, instead, flooding. In 2014 there was massive flooding in different parts of Sweden and on august 31 2014 I woke up to thunder at 5 a.m. and found the radar images below at SMHI:

Outside of flooding from thunderstorms the most prominent threat from the weather are the autumn storms. The storm Gudrun (Jan 8th 2005) where 20 people died in Sweden, stands out as an extreme example, that most Swedes remember.

Conclusion

The conclusion about my visit to SMHI and severe weather in Sweden is that since severe weather from thunderstorms pose such a weak threat it rarely causes any damage and thus not official warnings either. Since it does not pose much of a threat there is not really any reliable data about the occurrences either.

Thanks to Lisa and Joseph who was kind enough to allow me to visit and answer my questions!

Note: Any fact mistakes in this article is most likely my misinterpretation of Lisa and her colleagues.

Short interview with storm chasing legend Charles Doswell

doswell
Published with permission by C. Doswell. All rights reserved.

I had the privilege of getting ahold of storm chasing legend Charles “Chuck” Doswell. He was one of the first scientific storm chasers and was chasing back in the 70’s when no man in the right sense would dare going after a tornado!

As a respected meteorologist he has produced over 100 publications and is, according to Wikipedia, a contributor to the modern conception of a supercell. Thus, it is quite likely that a lot of the information and knowledge that you may hold on storms and supercells was once stated and figured out by this man.

 

1. Back in the 70’s you didn’t have the same technological tools which, I assume, made storm chasing more complicated than today. Is there anything you miss from those days, in terms of storm chasing?

Chasing today is MUCH more complicated than when I began in 1972.  What the technology does is increase our chances of getting to see a good storm and makes chasing safer.  I miss not having hordes of chasers to contend with on a chase.

 

2. If you’d look some 10 years into the future of the storm chasing community and industry. What do you think will be the greatest differences from now? Do you seen any threats?

I don’t like to speculate about what it will be like in 10 years.  I don’t have a good track record at such things.

 

3. You chase once a year as a special guest for Tempest Tours. What do you typically try to teach and share to the customers on these tours? I.e. what would you like people to know and understand when they go on a storm chasing tour?

I try my best to have my guests understand the basic physical processes they will see going one.  I also want to ensure they get an authentic chase experience – i.e., many hours of boredom, hopefully punctuated by all too brief periods of awestruck excitement.  Then they can appreciate that what they see on TV is not necessarily representative of what they can actually experience in storm chasing.

 

4. You have chased with several people over the years. Who would you like to bring out as the best storm chasers you know? What makes them so great?

I think Gene Moore, Roger Hill, Reed Timmer, Bill Reid, Tim Marshall … and others … are great chasers.  What they have in common is a relentless determination to succeed.  Some, of course, take that to an extreme …  [I don’t consider myself to be a great chaser.]

 

5.  What are common mistakes you see (far too) often other chasers do?

Core punching, failing to appreciate the dangers of what they’re doing, keeping their heads down watching radar on their laptops instead of looking out the window, failing to maintain situation awareness, driving like idiots … it’s a long list.

 

It is, in my opinion, interesting considering how storm chasing must have been back in the 70’s when you had no technical equipment and had to rely a lot of scarce weather reports and visual interpretations. It makes me think of that scene in the movie Twister when the main character let some dust pour through his fingers to “feel the wind”. Although that was not the method of choice in those days, obviously, experience and the gut feeling that comes with experience must have played a significant part.

As Charles mentions in the final question, a common mistake many modern storm chasers do is relying too much on their laptops.  The excellent guide “The Storm Chasing Handbook” by Tim Vaquez has a lengthy discussion about this as well: how chasing in the old fashioned style, as was the case back in the days, can make you improve your skills as a storm chaser. The technology will provide you with great data but it is only when you can combine this with experience and visual interpretations that you will become a truly great storm chaser.

With this I would like to thank Charles. If you’d like to read more about his current endeavors, check out his blog or website (which contains a gallery of amazing photos).