This scene was thanks to an overperforming MCS that tracked along the instability gradient from Iowa to southeastern Missouri (and is still going at the time of this post). In 8 years, I have only seen a late afternoon full double rainbow in downtown St. Louis 2 times. This was the second, not as good as the first, but still worth adding an image to the formal photo gallery. Larger version: http://stormhighway.com/stlouisphotos/storms_weather/double_rainbow_gateway_arch/h-1396.php The first one back in May 2010: http://stormhighway.com/stlouisphotos/storms_weather/double_rainbow_gateway_arch/
