7/13/04 REPORTS: Great Lakes/Ohio Valley


Had a meeting I couldn't miss at work until 4 today, so got a very late start. Too late, as it turns out. Storm was still going strong near Bloomington, IL a little after 4 so I decided to blast north and try to intercept. It looked good until I was within about 20 minutes of it - at which time it weakened and sped off to the SE. So all I got today was a rainbow, and 300 miles of driving. Oh well, that's part of chasing.

I see in LSRs that in addition to the multiple tornadoes, there were also hailstones 4 inches and larger - some confirmed by NWS observers.

To see what I MISSED today, go to:


SOMEBODY got some awesome pics!
I was torn between dropping down into IN to intercept the supercell rolling across IL or stay home and let the forecast big wind event come to me in GR.

I took off from Grand Rapids, MI shortly after spotters reported a tornado on the supercell in IL. Driving down US31 in IN I could see the darker storm skies to my SW. As I neared Rochester, IN I could finally get the Monticello Weather radio and it indicated a tornado warning. Unfortunately it was still too far South and West - near I74. I stopped at the library in Rochester - fast Internet access to check out the radar. The storm had turned quite a bit more South than when I started the chase. It looked like the path would take it near Indianapolis which was probably about the earliest point I could catch it. Didn't want to go that far and chase in that populated an area so I turned back to GR. Saw some mammatus in Rochester and some nice towers to my West near Holland, MI. That was about it. We got a little rain in SE GR and less lightning. No rainbow.
Highlights of the chase, if you called if that:
60 mph winds, 0.25 inch hail, torrential rains,
the liightning was pretty decent.

Chase the following counties that were warned for severe
thunderstorms: Barry, Clinton and Eaton County

Here is a couple pics of the baron xm radar, from tonight:

I have to remind myself to reset the clock on the laptop
to the right time, LOL

30 West Michigan Storm Chases and no tornadoes,
then again very few reports of tornadoes in West Michigan

I was watching that supercell in IL before I left to go to work this afternoon. I was amased to see it formed a huge bow echo that raced across KY & TN. It hit Huntsville, AL around 11:30. I work in a restaurant that is on a nice ridge and watched as the outflow boundary moved through. That was all it was but winds were over 50mph were I was and I watched as MANY power transformers blew in Huntsville. Saw the power go out all at once for a good part of the city. We have a pretty good view from where I work. Never seen an outflow boundary do so much damage.
I had the most amazing nine hour long chase day. From the very first tornadic cell in Illinois that popped, I watched it as from 1130 hrs ET as it moved southeast and approached the westside of Indianapolis. Not having mobile radar yet I was unaware it began to bow out and by the time it reached my location, it had picked up tremendous speed. I got caught in the path of it and had to seek shelter. A tornado warning was issued for southern Hendricks and Northeastern Morgan county around 5:30 or so. I was just west of that area, and the movement was SW at 35. No tornado or wall pics to speak of, way way too much wind and rain to see in front of your face... but we got a lot of everything else from some good tree damage to a car wreck to astounding mammataform/sunset and killer lightning 3 hours later.
I'll post pics when I get rest.
Well, yesterdays derecho was much further southwest than expected. I did actually go out and locally chase the MI stuff at around 11PM (just to watch the lightning, which was very intense). Went about 35 miles north of my house, trying to locate myself in front of a smallscale bow, since there was absolutely northing downstream from my house to watch.
When I got to my destination, I waited for 10 minutes and then got blasted with a 50MPH wind gust, then heavy rain and very small hail (smaller than pea sized). I decided to head back home, only to find numerous trees down closer to home (about 1-2 miles away!), with my weather station reporting a max wind gust of around 72MPH... Guess I should have just stayed home and enjoyed the show...
I ventured out last night as well. Didn't go far, 15 WNW Ann Arbor, as there wasn't anything to chase. Just waited for it to roll me, as I expected to be the case earlier in the day.

Ended up in perfect position for the cell that was migrating SE from Lansing at 10:30. And, as usual, it died before it got to me. 20MPH gusts, pea-sized hail, and lightning.

It WAS an intense lightning show! Got a good 1-1 1/2 hours of lightning on video. That made it all worthwile! Especially for a backyard chase.
Decided to forgo moving into my new apartment in 90 degree temperatures coupled with 75 Tds and chase the MDT risk/TOR box in central Illinois. Got out of class around 11:30am; saw the *early* supercellular development E of the Quad Cities; and decided it was catchable (as it was moving E/SE at 30). With NW flow at 500mb; S/SW at the surface; oodles of CAPE; and LI's around -8; I was expecting another "Plainfeild" type day. Targeted the Pontiac, IL region as the storm took more of a SE track; as expected.

Long story short; was chasing alone; road options and travel conditions became problematic; and I missed the large tornado E of Peoria by 15 minutes. By the time I intercepted the tornadic portion of the storm near El Paso; the meso was undercut like a whale's mouth and booking S/SE along I-39. Headed S on 39 from El Paso; eventually stopping S of Hudson to tripod/shoot video/stills as the meso wrapped up into a "mini-bell" shape. Encountered numerous trees/powerlines down near Farmer City and points SE towards Champaign. Ran into Scott Kampas; and later a few other local chasers; where we all converged at a Steak n' Shake in Champaign.

Post-chase jackassery transpired following an incident with Scott attempting to turn off his pager; loosing his cool following sporadic taunting banter from myself and others; and pitching the pager across the restaurant (Scott mentioned after the fact he ment to throw it down on the table; whoops). The pager came into close proximity of a baby; landing in a large pile of fries. Obviously embarrassed; frozen in a "did that just happen?" state; we apologized for this senseless act of violence against technology and humanity; and made amends with the family involved. Yet another strange chase-related debacle from 2004.

The evening concluded with a picturesque atom bomb CB to our N (near Chicago) at dusk. I departed for Kalamazoo; arriving back home around 1 A.M; only to see (on TWC) the storms I had been chasing hours before were now entering northern Georgia!

Drove from Southeastern OH into Indianapolis, plan was to head straight north out of Indianapolis. Checked online weather data, the huge cell was heading through Illinois and the spc had a tornado watch box in effect in Illinois. We figured we had time to catch the cell as it neared the Indiana border. The Mesoscale discussion on this storm had a nice "projected path" plot on the website. Quick change of plans added 150 miles to the trip but that seems to be the norm. You always go 300 miles more in a day than you expect.

Took I74 west and met the storm on the Illinois border. The front end of the cell was overhead and we saw a lowering on the front(SE) end. Took Highway 41 south to get a closer look at the potential wall cloud. Well the feature we were chasing was moving away from us rather fast and by the time we got closer we were more or less under a small section of the front of the storm when the winds and rain kicked in. That wind was intense, luckilly we were on the edge of it and able to drive N out of the worst of it. A few miles deeper into the intense winds and I imagine that we would have had to take shelter. There is no easy escape path from intense straight line winds. Never meant to get under the worst of any part of that storm but it was moving rather fast. Noting the tree damage later and the car and semi that were flipped over I was glad that we had not ventured too far under the core of that cell. Once we got under the rain free section of that storm we were able to do some stress free chasing.

When we got into Illinois, Vermillion county was tornado warned and so was one other county on the border of Indiana. Dewitt county , further W, had just gone tornado warned so things looked good. The storm quickly moved out of the Danville region so we tried to get to Piatt county ( Monticello) as fast as we could. Piatt county is one county SE of Dewitt so I figured that it too would go tornado warned. Nice mammutus overhead as we headed for the Monticello region. By the time we got there the storm had moved on. Chasing fast moving storms is very dificult.

Nice mammutus photos, nice lighting show both in Illinois and on the way home. My digital camera does not allow for good lightning photos and we had no other camera or video so a good lightning phot op was missed.

Power outage through much of Indiana on the way home. The map of storm reports from the spc shows the path of devastation from that storm.

The weather kiosks in the Indiana state rest areas are rather useful. Nice to know they have them. Next Indiana chase will start with a highway rest area before a WiFi hot spot.

Looks like we just missed the tornadic section of that storm. More or less as expected, I figured the further north we could get the more "tornadic" and less "derecho" the storms would be. Since our target area got pulled substantially West by the Illinois storm we were unable to get too far north in time.

Well it was a nice day for a 900 mile drive.
i left around 3pm from my house to go out to my mom's which is near danville as i saw the supercell that had formed in illinois had a south east path. tornado warning went up as i arrived at moms house, watched a nice lightning show for a few mins. before i moved westward towards danville. come to find out the storm shifted barely to a more southerly path and i couldn't catch up fast enough to get on the other side of the storm so i was stuck on the wrong side and got hammered with rain. never really saw any good structure from my vantage point as i didn't want to drive more west seeing as how i would have been even more in the core. all in all it was a good experience as i went back to mom's to observe a nice cumulonimbus forming to the north, got some great shots of it, will post them when i get them developed. storms that fired around 10pm had amazing lightning and good LP structure. i could have stayed out and watched the 10pm lightning show for hours, it was mother nature at her best.
Reviewing the synoptic setup, I am still astounded that such a strong tornado formed. Based on the CAPS analysis from 2 pm, there really is nothing on the synoptic scale that would suggest that strong tornadic supercells would form. I think it is very likely that this event was driven by the all-too-familiar extreme CAPE/low level boundary combo. The storms moved very far to the right of the mean flow, muck like the Jarrell, Texas storm of 1997. I am sure someone will do a case study...should be interesting.

The damage done to that factory looks like F4 to me...it really tore it up. From the prelim. damage survey, this tornado might have been even stronger (considering the two houses that were completely wiped). It's pretty unlikely that they will rate it an F5, but it is certainly a possibility. It sure is great that no one was killed. 8)

It wasn't a synoptically obvious event, but you don't ignore >6000 CAPE w/ 100kt@H250, 50kt@H500, 40kt@H700 events, even if it is unidirectional. Surface winds were progged to be southwesterly but ended up being more southerly.

No, that picture is not mine. It was allegedly taken with a Sprint camera phone. What an incredible year.

It wasn't a synoptically obvious event, but you don't ignore >6000 CAPE w/ 100kt@H250, 50kt@H500, 40kt@H700 events, even if it is unidirectional. Surface winds were progged to be southwesterly but ended up being more southerly.

This is true. I suppose the more amazing thing was how long the storms stayed relatively isolated...the merger into an MCS took a long time, allowing the storms to stay tornadic for quite a while.

I don't think the environment was ever uni-directional - except perhaps for the early elevated convection. Flow aloft was definitely NWerly, so with SW flow at the surface you have a quarter turn hodograph. At times, the flow did appear closer to 200 instead of 235, and may have been more like 180 near the storm updrafts resulting in motion opposite the surface flow (streamwise vorticity). There was a strong thermal boundary nearby (64F at Pontiac at 1943Z), but this was well east of the main tornadic cell, which occurred in a region where a number of new cells were generating and the southwesternmost storm produced (in an amazing 40 minutes from first echo) the large tornado. While not a textbook severe weather event, such events do occur several times a year. With extreme instability, amazing things can happen with marginal low-level shear - sort of the opposite of the IL event in April were incredible shear was combined with marginal instability - both yeiding significant tornado events.

BTW, I have a new appreciation for cell phone cameras - not a bad pic!

These tornadoes formed in an incredibly humid environment. Dewpoints of near and even ABOVE 80 degrees were observed in northern IL. I cannot recall another tornadic event with dewpoints this high before. Although I'm sure it has happened.
Reviewing the synoptic setup, I am still astounded that such a strong tornado formed. Based on the CAPS analysis from 2 pm, there really is nothing on the synoptic scale that would suggest that strong tornadic supercells would form. I think it is very likely that this event was driven by the all-too-familiar extreme CAPE/low level boundary combo. The storms moved very far to the right of the mean flow, muck like the Jarrell, Texas storm of 1997. I am sure someone will do a case study...should be interesting.

While an outflow boundary could very well have played a role, I don't think it was necessary. Based on the 18Z ILX sounding, about 2 hours before the tornado, there was 25-30 knots of speed shear in the lowest 0-3km. There is almost 90 degress of directional shear over 0-6km AGL, and 30-35 knots of speed shear over 0-6km. The 700mb winds were 35 knots, and I've rarely seen flow at this level less than 35 knots when violent tornadoes were produced. And don't discount 20 knots at 850mb, especiall with the direction shear present. With the amount of CAPE present, 20 knots at 850mb is fine. Also, this storm did not more very far to the right of the mean flow. The hodograph has an estimated storm motion to the southeast, which is pretty close to the direction the supercell moved. I do agree about the extreme CAPE, with the actual CAPE being nearly 4000 j/kg, that's a lot to stretch a vortex.

Keep in mind this sounding represents the atmosphere about 2 hours before the supercell produced the tornado. The midlevel winds strengthened throughout the day as the shortwave approached. I'm willing to bet the 0-3km shear was even stronger when the tornado was produced. Based on this sounding, I'm confident the environmental shear alone was conducive for violent tornadoes.

ILX 18Z Sounding


Jim Bishop
I'd have to agree with Jim here for the most part. I don't think it was THAT synoptically non-evident. I mean, you still had about 90 degree directional shear in the 3-4 km, which makes this no different that the typical Plain's southwest-flow aloft with se surface winds, which yields 90 degrees of veering. Wind profiles did strengthen through the day, yielding a more favorable environment than the 18z ILX shows. Yes, 0-3km SRH wasn't too impressive, but the extreme instability made than made up for it. I'm not entirely sure why NW flow events catch people "off-guard', since I've had plenty of success in these types of events. It's really no different than the more textbook setups, and there really isn't any more reason for storms to go MCS instead of discrete supercells as long as the shear vector is appropriately oriented to the convergence-inducing boundary; shear vectors perpendicular or 45 degree to the boundary tends to favor discrete activity, while shear vectors parallel to a boundary tend to favor MCS development... The 'perpendicular shear vector - boundary orientation' may be more common in the plains in the spring given the usual orientation of the dryline, but I've seen many northwest flow events away from the plains still with favorable orientation...

I don't feel the environment would have supported strong+ tornadoes if there was only 2000 CAPE available, as the low-level shear isn't that strong. However, increasing the CAPE to 4000-6500 changes the story signficantly...