Results
This chase case was for Friday, May 15, 1998. See reports below.
(no text of the reports because SPCs usual storm reports display does not go back this far, but text reports can be found at the NCDC storm reports online database, and I've saved a copy of it
here)
The severe/tornadic storms in Iowa moved into Wisconsin and Illinois, where they would continue to produce a few additional tornadoes early in the evening.
This was an interesting case because it seemed to frustrate many of you who chose to target SW Iowa. In looking at the data myself, if I had to make chase decisions, I would have done the same thing as you guys. I did a few hand-drawn analyses of the data, and I'll show the
19Z analysis as an example. In this synoptic analysis, surface pressure is contoured every 4 mb and dewpoint is contoured every 5 F with the highest dewpoints shaded darkest green and fading from there. I did not include contours near the edges of the map since the area of interest was in the middle of it. You can clearly see the position of the surface low and the warm sector with a decent dryline in Iowa and Missouri. That dryline stuck out like a sore thumb! You just don't see drylines make it into Iowa or Missouri often. Granted this dryline was synoptically forced, but it caught my eye right away. I would've been glued to it. Since I also like surface lows and backed winds, I would've tried to say near it, which would've put me southwest of Des Moines during most of the event. The surface low and attendant upper level shortwave moved quickly during this event, though, with the surface low moving from near Salina at 12Z to all the way into central Minnesota by 00Z. Thus it would've been hard to stay with it. The biggest storms in southeast Iowa formed along the dryline, however.
Arguably, the place to be during this event would've been on the supercell that produced several tornadoes, some strong and long track, that moved through Washington. This was a significant event for the area. As a frightened 13-year-old boy in Marion, IA sat glued to the TV as a news helicopted from KCRG in Cedar Rapids caught, for the first time on live tv, a bona fide large tornado as it passed northwest of Lone Tree in Johnson county. I can't find any video of that online, but I know it's in the archives at KCRG. This tornado did significant damage to Washington and was rated F3, as well as were a few other tornadoes spawned by this storm. To those of you near that cell, good job. You would've been very pleased. Here is a video of the big one early in it's life:
http://www.youtube.com/watch?v=IvNN5rXXKXo.
I want to thank all of you who participated in this case. I had fun putting it together and seeing how people would do with an uncommon severe weather scenario. I hope you enjoyed it. Congrats to those who saw any tornadoes. Several states were impacted, so the success was widespread. Enjoy your steak dinners!
