Tuesday, July 10, 2007

Dust Storm Hits Frankfort, Stronger T-Storms Usher in Relief Today & Tonight

It was certainly an eventful night last night at the Clinton County Fair. No, it wasn't the elephant ears or the giant rabbits that caught everybody's eye, but a dust storm that blew up over the area for about 2 minutes. It looked more like Arizona than Indiana. Our videographer Tom Harmeson came back to WLFI caked in dust. This storm was whipped up by an outflow boundary which is the cool rush of air that thunderstorms like to drag down from the upper-levels of the atmosphere. There were a few sprinkles and bolts of lightning, but that was about it. We once again dodged severe weather across the area last night.

This brings us to our excellent blog question of the day!

Hi Mike!

I have a question and was hoping you would have the answer. In my opinion, we did not have a “normal” spring season. In the years past we usually have some good thunderstorms that produce high winds and hail. However, this year, we have not seen the norm. In you opinion is this because of Global Warming, El/La Nina/Nino? I live in West Lafayette and I can’t even remember having any true thunderstorms this year. Has West Lafayette had any storms that have produced high wind or hail this year? If not, is that bad because we are not following our normal trends? Don’t get me wrong, I love the sunshine and hate the rain but I understand that a good mix is needed.


Kristen Van Laere

You have made light of what a difference a year makes. Thanks Kristen for your great questions. Our severe weather season has been unusually slow. Tippecanoe County has had only 1 severe weather day this year on April 11th with a report of a couple downed trees. I went out to check the damage and could only find a couple of small tree limbs. So even that report was questionable. This pretty much sums up our severe weather season here in the Lafayette area. We have had only 5 days so far with any severe weather reports in our entire viewing area. This includes tornadoes, wind gusts of 58 mph or greater, and nickel size hail or larger. Compare this with last year's 17 days with severe weather reports. The big stat that sticks out is we had 11 tornadoes in our viewing area, compared to just 1 this year. This is a huge drop-off.

What is the cause? Well, the atmosphere has been blocked by two unusually strong high pressure systems. One of these highs has been to our West bringing searing heat and Utah's biggest fire in its history. The other high is the more traditional Bermuda high that was so strong that it brought some of the worst forest fires ever to Georgia and Florida. It was also centered much farther west than normal. These two monster systems caused a logjam in the normal atmospheric flow. Instead of a sleek west to east flow across the Midwest it was severely disrupted. These higher jet stream winds usually give our thunderstorms spin and help in the formation of supercells which bring tornadoes, hail, and wind. The old saying to remember is that no flow aloft means severe weather is a no go.

The problem we have with this is that nature always seems to make up for lost time. Remember this past winter! This blocked flow will likely loosen its grip. Change is in the offing with cooling Pacific Ocean temperatures or a stronger La Nina developing. When we have a slow severe weather season early it tends to pick up later on as we head toward late summer and early fall. The reason for this is that patterns do shift. So we need to keep our guard up, including today.

I drew a severe weather outlook for us based on climatology of other unusually strong July fronts that have moved through the area and I would say that large hail and damaging wind gusts are likely. Now I am not expecting widespread severe weather, but isolated severe weather. Tippecanoe County really has not had a true dose of severe weather since last August 23rd. So even isolated severe weather is a big deal. Make sure to keep it here. Have a great day and stay safe.

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