|After going for nearly four months without a chase, I was
dieing to get out there again. The weekend looked to be an active one
with a setup in the Dakotas on Saturday. Sunday didn't look as good
with the instability, but with ample speed shear and a surface low parked
right overhead, the low level shear had enough veering to create a decent
chance for tornadoes in western Iowa.
|I didn't have great expectations for this chase.
The RUC showed low instability over the target area, and there was a lot of
rain and cloud cover lingering around that wasn't
helping the situation. I decided to go for it anyway, noting that
there was some clearing to the west and that SPC was sticking to the
forecast. I had to drive Jenny back to her house in Westchester that
morning so I didn't get on the road until almost 10, which was rather late
for an early afternoon intercept in western Iowa.
I made pretty good time, however, and the storms were holding off on
their initiation until late afternoon. There is one universal truth
and this chase was no exception in demonstrating the fact that Iowans cannot
drive. I guess they are so used to idling through town behind tractors
that once they get on the interstate they forget that the speed limit is 70
mph and have never learned common courtesy. Trucks and cars were
blocking the left lane, no one would pass each other. I cut off a
driver who refused to get out of the left lane, who then became irate,
driving along side me giving me the finger, flashing his lights, and then,
after great effort, finally made it back ahead of me so he could once again
block off the left lane so no one could pass. Nice.
|I finally turned off 80 west of Des Moines, kissing the
Sunday drivers goodbye, and headed north, just before highway 71. I
had stayed south where the instability was supposed to be better, but the
earlier convection and a rather strong inversion had kept anything from
firing behind the rain. Storms were severe and tornado warned on the
northwest side of the low near Sioux City, so I headed up in that direction
hoping storms would continue to fire to the east around the low. Near
Audubon I caught some building cumulus that was casting picturesque
|Not expecting to see much on this chase after the conditions
seemed that they would not pan out, I was ecstatic when storms quickly fired
overhead. One rapidly went severe warned and I plotted a course for the
intercept. "Woohoo!" Heading west toward a newly severe warned
|Heading back north coming in from behind on a
north-northeast moving storm.
|As I approached the storm, it appeared to be organizing with
an updraft base.
I passed a couple of chasers pulled off on the side of 71 so I pulled off
to see who it was: Scott Weberpal and Doug Raflik.
|Our storm was on a line that stretched from east to west and
wrapped around the northern portion of the surface low. Looking back
west as the storm stretched overhead with clear skies behind it.
|With the sun behind us we got some great contrast. A
new updraft tower going up on the back edge of the storm:
|We got back on the road to keep up with the storm.
Looking east at a base:
|A short while later a lowering condensed and a short inflow
tail formed on the front of it. This was probably a small wall cloud,
and you can see what might be a rear flanking downdraft clear slot behind
As we approached the base of the storm, we got caught in some rain and
hail from the new updrafts that were continuously spawning on the back edge
of the line. We stopped as the hail intensified but still could make
out of the base of the storm.
|A white snake-like tube dangled down from the base.
"Is that a funnel?" I thought to myself. Scott jumped out of his car
pointing up excitedly. I too got out to shoot a picture, but a wall of
rain soaked me and I had to retreat for fear of ruining my camera. The
funnel lasted only a few moments and I was unable to get a shot of it.
Here's a shot Scott nabbed through his windshield that I heavily enhanced to
bring out the funnel. You can see it as the white feature in the
center of the photo, descending below the cloud base:
|I left Scott and Doug and continued north into the core a
ways before turning east to intercept newly tornado warned cells on the end
of the line. By the time I had worked myself into a good position on
the southern tip of the line, all that left was an occluded base and
expanding outflow boundary. There was still a half hour left on the
tornado warning when I intercepted, but they cancelled it early. I
stayed on the base until I was sure it had lined out, however, since I saw a
similar looking base drop a tornado on May 5. I finally broke off at
about 7:30 and started my long trek back home, making it in by 2:30 am.
This chase was a ton of
fun. I went in with low expectations and I exceeded them, bagging a
white funnel cloud. Sure it didn't touch down, but it was a nice catch
after a four month hiatus. Although I still put 900 miles on the van,
this chase was also closer to home than most of my chases this season.
It was also nice meeting Doug Raflik and seeing Scott back on the chase.
- Iowan drivers lack courtesy, and they don't take well to aggressive
- Don't step out of the car to shoot storm features when its hailing
and pouring rain.