Saturday, April 16, 2011

04/10/11 April Mini-Supercell

A mini-supercell develops along a
pre-frontal trough
south of Cambridge, IL

Sunday, I chased locally near my hometown of Kewanee, IL. Sunday, was "supposed" to be the day for a good ole' tornado outbreak in northern Illinois that got even some of us feeling "tingly". Things quickly changed however Saturday night on my way home from work to "prepare" for Sunday's chase. After reviewing the 00z model-suite Saturday evening I wanted to throw the computer across the room especially after missing several "big" tornadoes in Iowa that Saturday evening because of work already that night. My heart sank as the model-runs showed the main target-area had pushed north into Wisconsin. Yes, I've chased there before, but I made a promise to never chase in that state again after a chase in that state in 2006. Mother Nature kind of made my decision for me especially when the tornadic threat looked to be confined to north of U.S. Highway 18 in Wisconsin where the terrain and geography are not too cooperative for viewing storms. Also, add the fact of the screaming early spring storm speeds off to the northeast I quickly chose to sit back instead of chasing "big bears" into the woods of northern Wisconsin. Anyhow, since chasing in Wisconsin was not something I was willing to do my options were somewhat limited. I could have either chased in northeast Iowa and maybe get some tornadic luck before the storms raced northeast into Wisconsin or I could of played close to home and hope that discrete supercells would form along a pre-frontal trough in west-central Illinois. In the end, I chose the lazy target and sat at home most of the day. I analyzed a pre-frontal trough that would erode the strong cap enough to allow convective initiation along the Mississippi River. Marginal instability was in place with roughly a 1,500J/kg CAPE, strong wind-shear with 0-6km shear at 60kts, and a moist boundary-layer with dew points around 60°F. By 7:00pm, I headed west on U.S. 34 after seeing some towers going-up and "blips" light-up to my southwest near Burlington, IA. I ventured west of Galva, IL where I found a developing mini-supercell at this point. It was quite photogenic upon arrival, but with the fast storm speeds neither myself or anyone for that matter could keep up with it. My Ford Escape unfortunately doesn't have warp-speed...grr! I quickly had to let that storm go and that was about it for my chase day. It was a disappointing day that had major potential in this area the day before, but it's the Midwest after all and the weather changes in a heartbeat. Their were several factors why we didn't get any tornadoes in northern Illinois. One, was the rather marginal instability in place with the presence of a strong cap. Strong deep-layer shear it seemed was too much to sustain vigorous updrafts as once storms developed the shear toppled them over. Also, the farther northwest position of the surface low and a more positive tilt to the upper-level trough didn't make this area as favorable for tornadoes as some earlier model-runs showed days before the event. The farther northwest position of the surface low and synoptic features shifted the tornado threat north and led to Wisconsin's biggest April tornado outbreak. Anyway, for those interested the real show ended up being in Wisconsin seen here. Storm reports from that area can be also found here. I've posted some photos from my relatively short local chase from Sunday evening below:

Convection bubbling at sunset...
(Canon telephoto-zoom lens (70-300mm))
I took this shot outside Galva, IL as an updraft collapsed
due to the
excessive deep-layer wind shear and a
strong cap, however
this is probably the strangest cloud-formation
I've ever photographed
as this thing was being stretched (vertically)
...if you COULD put this under
an updraft well anybody
would get excited
and it was the weirdest darn thing I've ever seen...
One of my best investments in recent years I've
made as a photographer...

(Canon 70-300mm telephoto-zoom lens)
Wide-angle shot of a developing mini-supercell at sunset in
Henry County, IL outside Galva, IL
Orphan anvils seen here as storms struggled with a stout cap
in place and strong wind shear aloft
A beautiful shot of distant convection at sunset...
Convection racing northeast at 55mph...
good luck keepin' up with that!
I've added a YouTube clip (above) of the "short" chase which
gave me an excellent test of my GoPro camera
(You'll be seeing a lot more of these clips in the coming
months, hopefully with a monster supercell in front of it)
Another telephoto shot...the storm speeds gave me
something else to photograph since keeping up with
these storms were not a possibility unfortunately...
Maybe the best shot on a fairly boring chase day?!
Spring starting to bloom as convection looms...
Love that telephoto lens...but still like my
Sigma 10-20mm wide-angle the best though...
Sunset with some nice "rays" along the western horizon
One last shot...on to the next chase Mother Nature...

That's all for storm chasing in at least the near future until the pattern really shows some "opportunities" in the next few weeks. It's spring however, so it won't be too much longer and I'm sure I'll find myself again in the "battle-zone". Heck, maybe even this never know?! Stay tuned...