11 March 2000 Case Study
A late-winter, surprise heavy snow event occurred during the morning of 11 March 2000. Forecasters anticipated 1-2 inches of snow, but the system became convective, resulting in heavy snow in a narrow band in Missouri and Illinois.
Snowfall occurred mainly during the morning hours (0900—1500 UTC) in east-central Missouri.
“Thundersnow” was observed at Spirit of St. Louis (KSUS) and St. Louis International (KSTL) airports for approximately 2 hours, beginning shortly after 1200 UTC.