Omaha Tornado Chaser: 4/9/11 Iowa chase

This day was already my 2nd chase of the season which is pretty impressive for this time of year in my area. Last year, I don't believe I went out until the end of April! This day was well advertised for almost the whole week with the only differences being on location, and also how strong the cap would be. The last part was a concern because it would be possible despite the unseasonable warmth and moisture, no storms would form due to the cap in the atmosphere. Finally, the night before the forecasts focused on northeast Nebraska into Northern Iowa as the prime area. Besides the extreme instability that was forecast to develop, there would be a lot of shear available for supercells with large hail and tornadoes.
I hung around Omaha waiting for signs of initiation. At about 430, i took off up I-29 with a plan to go to Onawa, Iowa. There was a storm forming slowly in northeast Nebraska west of Onawa, moving in the direction of that city. I made it up to the exit and went west of town about 3-4 miles. I had a great view of the storm the west and north of me. The storm didn't look all that great for about the first 30 minutes i was sitting there. The only thing that was impressive about the storm at first was the amount of lightning up in the clouds, and also soon after i was parked, the inflow winds into the storm increased like crazy to consistently 30-40 mph. There were new storms firing back by Madison and Norfolk Nebraska. I was just about ready to leave the original storm i was watching and head west about 50 miles towards the new storms which were supposedly in a better environment for tornadoes. I was literally typing in the new city in the garmin when i looked up at the back of the storm and started to see all kinds of rotation. At one point I almost felt unsafe enough to move as an intense area of rotation that looked like it was trying to form a funnel was right above me!
I filmed this for a bit and then looked out to the northwest and saw all kinds of dust blowing around. I immediately noticed that rather than it just being blowing dust, what i was seeing were gustnadoes forming. These aren't true tornadoes because they normally aren't attached to the cloud base but are still signs of strong shear, updrafts, and rotation very near to the ground.
I proceeded to take some really cool video over the next 10-15 minutes. Near the beginning of the video, I am suddenly hit by one of these gustnadoes as it goes right over the top of me! I also filmed a strong RFD go across the field and into the trees about 1/4 to 1/2 mile away. It was cool to see all the debris and dust being carried by this and when it hit the trees a bunch of birds went flying out! The storm was now really getting its act together and was tornado warned. I checked the radar and the main area of circulation was right over the top of me!
The storm was beginning to move into western Iowa further now. I hopped in the car and headed back east through Onawa. The sirens were blaring, but of course I saw several people including kids out playing and walking around still. I got out east of town a few miles and had another great view of the storm to my north. It was again kicking up these gustnadoes. I pulled over and started filming and not more than 30 seconds two very large, intense ones formed in the corn field in front of me. They were intense enough and large enough that for a while i thought for sure I was seeing a tornado form. I kept looking up at the clouds though and didn't see any real strong rotation. You could even see these little tiny suction vortices form right in front of me about 50 feet or so and kick up some dirt and old corn stalks. The other circulations were strong enough that there was now old corn stalks falling from the skies!! The larger gustnado kindof fell apart and moved onto the east so I hopped back into my car and went east as well.
The storm was heading towards Mapleton, Iowa, so I continued east down Hwy 175. This is where I made my "mistake" of the night. 175 turns north and comes into Mapleton from the southwest. I was taking a look at the radar and felt there was no way I could beat the storm to Mapleton, so I continued east on Hwy 37 until county road L32 where I headed north. This road would take me into Mapleton from the south and also give me options to go east if need be. As i got within a couple of miles, I began to see reports of tornado going through Mapleton. I was approaching the storm and could begin to see a very dark area that was kindof fuzzy/hazy in the center of the storm. Along the edges of this dark area, it seemed to be rotating. At first, I wasn't sure whether this was the tornado. After seeing other reports and video, though I am sure I saw the ending of the tornado and what I was seeing was all the dust being thrown around in the air from the tornado. I still wish I would have gone up on 175, but I wanted to make sure I could go east if I wanted to and not have to take a gravel road, so who knows what would have happened.
It was now nearly dark, so for a while i headed east(on mainly gravel roads) and wanted to find a good spot for lightning shots. I was close enough to the storms yet though that there was usually strong winds or light rain falling, so I never did stop for pics. I did stop at one point because i could see a wall cloud being illuminated by the lightning, but never saw a tornado. I started heading home all the while watching on radar and online the reports of a major tornado outbreak ongoing. I never chase at night if possible, but this night I wish I would have kept on chasing. The storms continued to allow great visibility of the tornadoes even after dark. There was constant lightning with the storms and the flatter terrain allowed great visibility as well.

Below are some of the radar grabs of the storm and the severe weather outlooks:

curved hodograph showing the amazing directional shear

moderate risk from Omaha on north and northeastward

tornado probs

very high probs of large hail

severe storm just as it was developing at 615 pm(i'm located at the white circle with the dot in the middle)

storm relative velocity grab at 647 pm. notice the purple box is a tornado warning. i'm still located at the white circle. the small purple triangles are signals of strong rotation

hook starting to form as storm heads towards Mapleton

large hook on storm as possible tornado heads towards Mapleton

monster supercell heads towards odebolt and arthur, with tornadoes later confirmed

Here are some of my pics. I didn't take a lot as I was mainly videotaping the gustnadoes, etc. I have my brand new HD camcorder for this season, but it didn't come with the cord I need to transfer video onto my computer, so my video will be up in a week or so.