Stormtalk

Wednesday, 18 August

Don’t forget to submit a comment to the thread: Stormgasm.com T-Shirt and DVD Giveway, in order to be entered in the contest which ends September 10.

Satellite image of the Atlantic tropics August 18. You can see a tropical wave near the coast of Africa that computer models indicate will become a tropical storm this weekend.

With large, violent tornadoes in North Dakota/Minnesota last week and the rope tornadoes that occurred on Monday in Colorado, we continue to see the results of an active late summer severe weather pattern. In fact, there are two more setups expected this week, one today across South Dakota and Minnesota, and another on Thursday over the same region. The tornado setups just keep coming here in 2010, and every time you think it’s over, another photogenic tornado occurs.

There are plenty of reasons why things have been so active as of late, even for the last couple months. But the two main reasons, IMO, are the strengthening moderate La Nina combined with the warm Atlantic Ocean waters (positive Atlantic Multidecadal Oscillation). The La Nina (among other things) has kept the jet stream quit active across the northern Plains, and the warm Atlantic has helped keep robust low level moisture present across the Plains. Both conditions are needed to sustain an active severe weather pattern.

The other developing weather story is in the tropics, where computer models are indicating that a tropical storm (or possible hurricane) will develop by the weekend (August 21/22) over the far eastern Atlantic. I’ve talked about the tropics a little over the last couple weeks, and have mentioned that a combination of factors has kept them quiet relative to what has been expected for this season. Those factors, such as dry air, African dust, and the wrong phase of the MJO, haven’t really changed all that much. But, computer models insist a tropical wave coming off Africa will have enough energy to become a tropical storm this weekend.

This doesn’t really change what I said recently, that the tropics look quiet and less active than expected by many seasonal hurricane forecasts. Having a Cave Verde tropical storm or hurricane in late August is normal. Actually, we’ve only had one hurricane and two named storms so far. By now, we should have had three named storms with one hurricane. So, this upcoming storm in the Atlantic (assuming it develops) will basically keep this season at a normal pace. I do think dry air and African dust are going to be a problem, but given time and distance, things can change and maybe we’ll see our next hurricane by this time next week. However, for it to have a good chance of becoming a major hurricane, those inhibiting factors need to improve.

 
- Jim

Monday, 16 August 2010

 
August 12 Tornado in North Dakota rated EF3: Photo courtesy NWS Bismarck, ND

EF3 Tornado in North Dakota August 12, photo courtesy NWS Bismarck, ND

On Thursday, August 12, a violent tornado swept through Bowbells, a small town in northwestern North Dakota. One person was killed and one injured in their automobile Thursday evening, when the nearly quarter mile wide tornado crossed highway 52, east of Bobwells, carrying the automobile several hundred yards. The tornado is also responsible for severely damaging a home in the Bowbells area. The official rating of the tornado from the NWS damage survey team in Bismarck, ND is EF3.

Like a broken record, violent tornadoes continue occurring this summer across the northern plains. Each time I make a post like this, I wonder if this may be the last time until maybe the fall that I talk about a violent tornado again. Yet, these events just keep happening.

So, it’s reached the point where I’m wondering if the fall tornado season will be more active than normal. It’s clear we have been unable to break the summer pattern of violent tornadoes. And of all people I know occasional tornadoes are common in the late summer across the northern plains. But when you have multiple killer, violent tornadoes like we’ve had, it’s unusual, and representative of a large scale weather pattern.

I guess we’ll have to wait and see if this active weather pattern continues this fall. If it does, storm chasers may have an unexpected encore to what most consider one of the best spring storm chasing seasons of the decade.

 
- Jim

Saturday, 14 August 2010

Photo taken in Milford, CT August 14

Photo taken in Milford, CT August 14

Cirrus cloud in Milford, CT August 14

My wife and I found ourselves in Milford, CT just after noon on Saturday. I’ll get into why in a minute. But, we both saw several jets flying in the air above us, leaving interesting looking contrails. The contrails spelled out ‘HOT SUMMER’. I found this kinda odd. I mean, I know it’s been a hot summer up here and everything, but it’s been in the 70s for the past few days. At the time the picture was taken, it couldn’t have been any warmer than 73 degrees. Oh the irony.

The other issue is why were several jets flying over Milford, CT leaving contrails that spelled out anything at all? I wonder what the point of that was. The whole thing just strikes me as very strange.

Anyways, the only reason we were there was because we had gotten up to make a noon appointment and run some errands. Well, on the way to our appointment in Milford, while driving north on the Merritt, we got into a car accident. Yep, some guy in a pick-up truck rear-ended us. And this is so typical of Connecticut drivers. Everyone in front of me was slamming on their breaks and riding each others buts. I wasn’t, so I avoided hitting the guy in front of me. Too bad the guy behind me wasn’t paying more attention. Luckily, the damage to the rear of my car appears mostly cosmetic. Anyways, that was fun. Good times.

- Jim

Thursday, 12 August 2010

Visible satellite image over the Atlantic basin on August 12

It’s mid August and the tropics are quiet. If you look at a satellite image, you might think its May or June instead of nearly the middle of the hurricane season, since it’s hard to find even an area of thunderstorms anywhere across the Gulf, Caribbean or Atlantic Ocean. Based on NOAA’s 2010 Atlantic Hurricane Season Forecast, and Colorado State University’s Forecast, this should be a very active season. Even looking a climatology, we are heading into the more active part of the hurricane season. About a week ago, I event talked about how I thought the tropics would become much more active by now and into next week. Yet, the tropics are silent. So what gives?

Well, from what I was seeing last week around this time, the MJO was moving west into the Atlantic Ocean. This was bringing enhanced, large scale, rising motion into parts of the Atlantic, and helping potential tropical waves to develop. That trend was supposed to continue, but it didn’t, as seen quite clearly from today’s satellite image of the Atlantic Ocean.

So now we are left with no help from the MJO. Depending on how much more the MJO moves east and strengthens, it could further impede tropical action in the Atlantic for the next week or so. Add to the list an abundance of dry air and upper level disturbances all over the Atlantic basin and you are left with the sound of crickets.

But, according to Dr. Philip Klotzbach (the Colorado State Hurricane Forecaster), “it is too early to think that this is a seasonal forecast bust”. He is forecasting 18 named storms and 10 hurricanes this season.

So, we’ll have to wait and see what happens. The true peak of the hurricane season begins August 20 and goes through around mid October. That leaves a lot of time to play catch-up. But, Klotzbach’s forecast calling for 18 named storms and 10 hurricanes is going to be really tough to reach, considering we stand at 1 hurricane and two tropical storms so far this season. Although, water temperatures remain very warm, so anything’s possible.

But the way things look now, it could be late August or even early September before things really pick up again. That isn’t to say there won’t be a random storm in the open Atlantic before then. But, the big ramp-up in tropical storm and hurricane activity I expected by now just isn’t panning out. We’ll see though, something always changes with the weather, and Klotzbach sure seems optimistic.

- Jim

Tuesday, 10 August 2010

Jesse Duncan, shirt model. Was my awesome and fearless chase driver May 10.

Jesse Duncan models back of shirt.

2003 Tornado Highligh DVD

T-shirt and DVD Giveaway!
 
With only one limited edition Stormgasm.com t-shirt remaining, I thought it would be nice to give it away to a lucky commenter here on Stormtalk. All you have to do is leave a comment in this thread, responding to the question below. Then, on September 10, I will announce the winner, who will be selected using a random number generator.

To make things more interesting, the winner will also receive a 2003 Tornado Highlights DVD from Stormgasm.com. All the winner has to do is email me their name and address, and I’ll have the t-shirt and dvd shipped to them. Just make sure you leave a comment in this thread responding to the question below to be entered in this contest.

Good luck!

 
The question: Among all the videos of tornadoes available on youtube, on storm chaser websites, and on DVDs and video tapes, which tornado is your favorite, and why?

(Feel free to elaborate, especially if it’s video of a tornado you saw personally, or were affected by in some way. Also, you can list more than one video if you have more than one favorite. But, let’s try to keep this to a maximum of five.)

- Jim

Tuesday, 10 August 2010

EF4 tornado confirmed in Minnesota…

 
It is now confirmed by the NWS damage team that the tornado that occurred Saturday, August 7 in Wilkin County, MN was a low end EF4 tornado. More information here.

I also wanted to share this tornado footage someone posted on YouTube of the Wilkin county tornado, likely shot after it caused the EF4 damage in Minnesota. This video is amazing. It reminds me a lot of my Manchester, SD tornado footage from June 24, 2003 after the tornado move north of town and into open farm fields.

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Monday, 9 August 2010

On Saturday, August 7, a supercell tracked from southeastern North Dakota to west central Minnesota, producing at least two tornadoes and causing significant damage. Thankfully, there were no major injuries or fatalities.

The most significant damage occurred in southeastern North Dakota where a pickup truck was thrown a half mile into a field, with the engine block thrown nearly two thirds of a mile (damage pics here). The tornado was nearly a half mile wide at that time. According to the NWS office in Grand Forks, North Dakota, this tornado was at least an EF3. But, it could have an even higher rating on the Enhanced Eujita scale, once the final damage survey is complete.

This is all very impressive. I was out of town when the tornadoes occurred, and didn’t have a chance to look at the setup. I did glance at the SPC Outlook at some point on Saturday, and they only had a 5% risk for tornadoes. They may have upgraded at some point, but I don’t know. The point is this event didn’t look like one likely to produce violent, photogenic tornadoes. Yet, it produced at least two tornadoes, one with at least an EF3 rating. That’s impressive.

This tornado event is a great example of a day that ends up producing good tornadoes, even though the setup didn’t look that great. These kinds of events happen more often than you might expect. For example, I chased several tornadoes on May 12, 2004 in southern Kansas. That day the SPC had a 5% risk for tornadoes. But, one supercell ended up producing several tornadoes, one which destroyed a house in Harper County, KS. Another was a large wedge tornado, rated F4.

It’s a very good thing these tornadoes moved through rural areas. Had they struck in a more populated region, significant injuries and possibly fatalities may have occurred.

Oh, and this is another day to add to the list of significant August tornadoes. This year has simply been amazing. I mean, seriously, just when I think the season may be winding down, there’s another violent tornado to talk about. It makes me wonder how many more violent tornado days we’ll have over the next few months. We are, after all, getting closer to the fall ‘tornado season’. There are usually a couple good tornado setups in the mid September to mid October window. We’ll see…

- Jim

Friday, 6 August 2010

Nine weeks into a hurricane season that is expected to be very active has so far been on par with a normal season. But, it is still relatively early in the season, with plenty of time for the tables to turn.

Over the past several weeks, Atlantic water temperatures have been at some of the highest levels since 1950, which provides significant fuel for tropical storms and hurricanes. But as of late, wind shear, dry air and an abundance of African dust have all hindered tropical storm and hurricane development. These factors, in spite of the warm water temperatures, are why we have only seen one hurricane (which was weak) and two tropical storms so far this season.

But, I think the tides will be turning over the next several days to two weeks, with more sustained tropical storms and even hurricanes across the Atlantic. The first reason is because climatology (image below) tells us that tropical storm and hurricane activity dramatically increases as we head into mid August. But the more significant reason is due to the Madden Julian Oscillation (MJO) moving back into a phase which favors the development of tropical storms and hurricanes across the Atlantic Ocean.

Hurricane and Tropical Storm Climatology from NOAA

Atlantic Sea Surface Temperature Anomalies

For about the past week or so, the Atlantic Ocean has actually been under a phase of the MJO which causes large scale sinking motion, making any tropical disturbance fight an uphill battle to develop into a tropical storm, let alone a hurricane. Then, factor in the wind shear and dry air issues, and no disturbances really stood a chance of becoming anything significant.

But now, the rising motion associated with the MJO has moved into the eastern Atlantic, and this should continue to spread westward into the Caribbean over the next week or two. This should really give the hurricane season a huge boost, especially compared to the way it’s been lately. If I’m right about this, then by this time next week we’ll be talking about a tropical storm or even a hurricane somewhere in the Atlantic basin that stands a shot of becoming something significant. At the very least, we’ll be talking about something developing that stands a decent shot of becoming significant. The only concerns would be how much wind shear persists, and how much African dust continues to drift into the Atlantic.

So, we’ll see what really happens over the next week. Either way, the season should pick up soon.

- Jim

Thursday, 5 August 2010

4 people died in Ohio Wednesday from a strong line of storms producing high winds…..
 

SPC storm reports for Wednesday, August 4, 2010

According to the AP, high winds associated with a line of severe thunderstorms knocked over barns being renovated Wednesday at Ohio’s largest egg farm near Hartford, killing two workers. Based on the SPC storm reports page, this occurred around 1 p.m.

A couple hours earlier (according to foxtoledo.com), the same line of storms caused a cinder block wall to blow over near Edgerton, Ohio, falling onto and killing an eighteen year old male construction worker. According to the coroner, the death was caused by injuries from blunt-force trauma. Hours later in Cumberland, Ohio, high winds from thunderstorms caused a tree to fall onto a woman, killing her.

More information about the Edgerton, Ohio collapsed high school wall.

When I think about severe weather related deaths, I usually think about tornadoes, flooding, even oppressive heat. But, fatalities from strong straight line winds are usually not on the list. Yesterday, a line a severe storms producing damaging straight line winds moving through Indiana and Ohio is responsible for all of this. The storms moved quickly east and evolved into a long-lived, damaging squall line known as a derecho. This derecho moved all the way to Pennsylvania, Maryland and Virginia, causing over 200 damaging winds reports.

Well, at least this high wind event in of itself isn’t surprising. During the summer months, the Midwest is notorious for having damaging wind events which sometimes extend into parts of the Mid Atlantic. It’s the combination of quality low level moisture, hot temperatures and upper level disturbances moving over the top of an intense heat ridge that triggers these events.

- Jim

Tuesday, 3 August 2010

 
Storm chasing tours and their benefit to aspiring new chasers…

Today I saw an interview with a reputable storm chasing tour owner. The question came up about who would pay two to over three thousand dollars for a week to ten days of storm chasing. This reminded me of an important option aspiring new chasers have that shouldn’t be overlooked. I’m talking about signing up for a chasing tour as an alternative to storm chasing for the first time with little knowledge of storm chasing, let alone meteorology.

It makes sense when you consider all the costs associated with storm chasing. First and foremost, you have to set aside a large chuck of money for gas alone. Then, you have to eat and pay for hotel rooms daily. You also have to worry about wear and tear on your vehicle, or rental car fees. Finally, you have to put forth an enormous amount of time and energy to make your own forecasts and go through the stress of chasing. That’s an involved list if you really think about it!

So, if you have never been storm chasing before, and you are not comfortable forecasting tornadoes on your own, paying a couple grand or more for a chasing tour can be highly beneficial. Most of these tour groups pay for you hotel room. They give you a comfortable seat in their van and do their personal best to find you a tornado. On top of that, most of these groups teach you what they know along the way. So, as long as the tour guide is experienced with a good track record, you really have nothing to lose.

As someone taking your very first storm chasing trip, going storm chasing can be very frustrating. Not only do you have to pay for everything, but you have a lot of stress just trying to forecast tornadoes. I mean, even I get frustrated, and I’ve been storm chasing for over ten years! On top of that, you have to find your own hotel every night. When you get tired from all the driving and stress, you still have to stay on top of the latest changes in the weather forecasts to give you the highest chances for seeing a tornado. I mean, you need to know if a drive from Oklahoma to South Dakota overnight is necessary to witness that one, awesome tornado. Sometimes, it really does come down to last minute decisions.

Most of all, it’s dangerous for first time chasers to go storm chasing without prior knowledge of supercells, tornadoes, and meteorology in general. Storm chasing is simply a dangerous hobby unless you have the knowledge and experience to practice it in a safe manner. In fact, I know some professional meteorologists who don’t know the first thing about storm chasing. That’s because storm chasing requires a combination of meteorology skills and experience. And without real experience out in the field chasing storms, there’s really no way to learn this hobby. That’s what makes taking a chasing tour as your first chasing trip so valuable. Doing that, you learn how to chase storms without putting yourself in a dangerous situation. Plus, your odds of actually seeing a tornado and having a great storm chasing experience increase significantly.

So, if you are an aspiring storm chaser, you might consider giving a chasing tour a try to get your feet wet. That’s my opinion anyways.

- Jim

Monday, 2 August 2010
 

A tornado hit Penola, Australia Saturday evening…

Map of Australia. The "A" indicates the location of the tornado on July 31

According to ABC South East SA, a tornado hit Penola, Australia Saturday evening (July 31) at 6 p.m. ACST. There was so much damage the South Australian Government is providing $250,000 in aid to help the clean-up effort.

This tornado is somewhat unusual, as it occurred during Australia’s meteorological winter. But it’s not the first time Australia has seen a damaging August tornado. Back on August 25, 1999, a tornado went through Perth in Western Australia. That tornado left a 100 meter wide damage path and trapped several people in an apartment complex.

Australia averages about 20 tornadoes per year, most of which occur in New South Wales. From 1795 to June 2003, New South Wales reported 364 tornadoes. Compare this to the United States, which averages over 1,000 tornadoes per year.

- Jim