Sunday, June 15, 2008

Thursday, June 12, 2008: central Kansas

We started the morning in Omaha, and I had a message from Jen, the Free Press reporter from our 2006 trip. On our way south, I called her back and did a brief interview with her about this year's chasing and the previous night's tornadoes (which had sadly killed 4).

Anyhow, our thought was that we would stop in Topeka, KS for lunch and a data stop. We did that (lunch was, for me, an awesome sub and for CB a wrap from Jersey Mike's) and determined that our destination would be near Wichita.

Now, on the way, CB kept on looking at the city of El Dorado, west of Wichita, and singing "El Doradoooooo", trying to sing to the tune of Canyonero, the Simpsons SUV. Anyhow, after a while we both took it as a sign that, instead of Wichita, we should head to El Dorado.

We got to the toll booth at the turnoff from the turnpike when who should call, but Paul Sirvatka. He asked where we were and after about a minute of perusing data (he was actually already in the CoD lab), he stated confidently that we were in the right place.

Sweet.

We went into town and pulled up to the side of a Best Western. As soon as we puled in, a RADAR on the flatbed of a truck pulled in. It had University of Maryland painted on it.

We checked tonnes of data and decided that Paul was right. There was a northeast-southwest convergence line or stalled front just north of us; where we were there was a south breeze, temperatures in the low 30s and dewpoints in the low 20s. It was juicy.

We went to get some snacks and drinks, as we knew that we wouldn't be eating for quite a while. While waiting for CB I talked to a couple of the guys with the RADAR.

We left town and went just a little bit north, in order to watch the goings-on at the convergence line. This is an example of the towers that were going up and quickly fuzzing out on us.


So we waited and waited, although not for too long; soon enough one of the towers went higher than the other and was much MUCH broader than the others. It was seriously ingesting the good air.


We decided that we needed to go after this storm, which we did. As we approached it, the weatheradio went off. Tornado warning, Doppler-based, for this storm. SWEET!

So we caught up to it and saw a lazily-rotating wall cloud. And we kept on it. And on it. And on it. At one point, I can say, I was puzzled as to why it wasn't producing. To wit:


And then:


Shortly after this picture we passed by lots of other chasers, like cloud 9 and Roger Edwards. I really wish we could have stopped to talk to him, but we were in chase mode.

Wxdog called, asking us where we were. He told us that the storm we were on was one of 2 really good ones, based on RADAR. Again, of course, we were chasing blind (although I'll say a bit more about this later). Big hook, he said.

Anyhow, this storm hit the mess of construction that is the Turnpike interchange near Emporia, so our road options were all of a sudden cut off. D'oh!

We went into Emporia to get a data feed, and the RADAR shot made my jaw drop.

We couldn't catch the storm we had been on, but that was okay--I mean, just look at the hook on the storm south and west of Emporia.

We blasted south and this is what we got:

It was weakly rotating, but the heavy precipitation (yes, more HP supercells) was obscuring the wall cloud. This one went east and the precipitation from the next one caught us, so we dropped south. Saw the same thing there. It was starting to get dark and the storms were looking very HP, so I suggested we get a room in Emporia. Just after I said that, the weatheradio buzzed again. Tornado warning, for the storm just southwest of us. Okay, well, apparently I can't really call them properly. :P

We caught that storm and it was dark and impossible to take pictures; there was lots of neat outflowy stuff and maybe a wall cloud, but the storm wasn't going to produce.

We drove back to Emporia in the pouring rain, and CB got us a discount on the room. And I quote, "because she's awesome". I'm serious.

So that was the end of our 2-day central and southern plains chase.

I want to muse on why the storms didn't produce tornadoes that we saw; there were a few reports that afternoon, but way fewer than there would have been, due to the fact that just about every chaser on the planet was there.

I think, after much rumination, that the lack of low-level shear (something we knew would happen; in fact, I hadn├Ęt even expected such awesome supercells) was the main limiting factor to the storms. The low-level shear wasn't enough to keep the outflow or HP cores of the storms from disrupting the inflow for long enough for tornadoes to happen. That's my opinion, anyhow.

The only other thing I can think of about this trip right now is this: I don't want to chase the USA without in-car RADAR. Although we hit the exact right spots (in my opinion) by going visual, I would like to have had the extra assurance of the RADAR imagery to confirm that we were on the right storms. There is a bit of a debate going on at Stormtrack right now, though, that maybe in-car RADAR might not be the best thing, as it creates complacency that you can get closer to the storm without being in danger. Of course, this is leading to some problems because the RADAR imagery is usually at least 5 minutes old, and if the update doesn't happen as expected and you don't recognize it, you could be in danger. If you're not looking out the window, which is apparently what has been happening from time to time.

Rant off.

It was a great chase. Thanks to Wxdog for capturing some information and for some nowcasting suport; to JJH for the same, and to CB for being a good chase partner, even though the music on my iPod might not be to your liking.

Wednesday, June 11, 2008: northwest Iowa

So Miss Shannon Cool Beans (CB) and I left at about 8:30 AM to go chasing on Wednesday morning. I had just gotten off night shift, so I was a touch tired. Despite that, I didn't sleep much in the car--maybe an hour or so after Fargo.

Anyhow, we got to Sioux Falls, SD just before 4:00 PM, and coincidentally JJH called us to ask where we were. We told him and he said that we were in a good spot, as initiation was occurring just west of us, and that we should be able to see it. As we had been clagged in with cloud since about Fargo (along with some brutal near-zero visibility fog north of Watertown), we weren't looking hard enough. But then we opened our eyes and could see, just off to our west, a line of darker cloud bases embedded
within the cloud deck. We did a data stop and saw that we were, indeed, in just about the right spot. So we went east by about 10 miles, where we were much better able to see things off to our west.

Towers were going up but they were kinda fuzzy--indication that the instability wasn't yet being realized well enough to complement the shear.

Well, we kept on going east, trying to stay ahead of the line and trying to see if one storm would take over. It was hard to be sure, but one off to our southwest looked pretty good. We headed in that direction and soon heard the first tornado warning of the day on the weatheradio. We extrapolated its future location (seeing as how we were chasing as luddites, that is without mobile internet), and got in place. When we got there, we could see an area of rotation, but it was hard to pick out because the storm had started to rain pretty heavily. Still, this is what we could see:

Well, after that it got ugly. The line of storms had grown, evolving into a north-south line of HP supercells. Some tornadic circulations were in there, but it was mostly heavy rain. Here's an example of what the RADAR looked like.



The rest of the chase was done "visually", although I use that term loosely. What we could mostly see was a lot of rain. At one point we were in the middle of a tornado warning, where the town we were in (Primghar) was named. It got windy and the rain got even heavier, and I got scared. Turns out I was right to be scared, as some other chasers got a direct hit from a tornado that evening that they couldn't even see. Scary.

Iowa is flooded. Well, at least the part of it we saw. I didn't take any pictures of all the standing water, but I did take a picture of what the rain was doing in Primghar.


We got some pictures of another developing storm, but we were pretty much done for the day; a line of embedded HP supercells is not something I think I want to chase, ever again. Too scary, as you can't see anything.

We overnighted in Omaha. A town where you can't get anything to eat aside from Taco Bell at 1 AM. Unless you go to the casino. Yikes.

Back from the trip

I'm still recovering physically, but I'll have a full recap with pictures and RADAR captures later today.

Tuesday, June 10, 2008

First long-distance chase of the year

In the morning, SM and I will be taking off for (hopefully) Omaha. I've been watching this setup for a couple of days and it looks pretty awesome. I think the outbreak region will be bimodal, with one area up by Aberdeen, SD, and another down by Omaha. The better moisture and instability, as well as the better dynamics will be in Nebraska.

Then the next day, it looks like southeast Kansas, before coming back home the next day.

SM and I missed the last outing that JJH, JDS and DD hit, so this is our vengeance, as they can't make it.

On another note, my last forecast for June 4 seems to have worked out.

Let's hope this one works out, too.

Monday, June 02, 2008

Convective outlook for June 4, 2008

I know how I've talked about not relying on the models too much, and I try to practice that all the time. However, in the 24 to 72 hour forecast period, one must rely on model output.

Well.

This is now the second consecutive day where the models have been pointing to a pretty serious central plains setup for Wednesday. Specifically, near the Kansas-Nebraska border.

Moisture--well, dewpoints are already 20°C or higher.
Instability--with cooling moving in aloft, MLCAPEs look to be in the 2500 to 3000 j/kg range.
Lift--a warm front is slated to be draped across the region.
Shear--with a 50 knot 500 mb jet streak moving across the region, 0-6 km shears look to be 50 to 60 knots.

Additionals: a good upper jet (70 to 80 knots) is forecast to be nosing into the region.

If I could, I would be leaving tomorrow morning to go to chase the Nebraska/Kansas border. Now, I can't guarantee that tornadoes will occur, but I will say that very large hail is likely with this setup, as well as flash flooding. But if a storm can ride the warm front and ingest the lower LCLs and low-level shear, this setup could produce a prolific tornado producer. Here's a comparison: this setup looks to me a lot like this day.

We will see in a couple of days if I'm right. Or more correctly, how wrong I am.