Chase Logs 2009
Evening Echoes: The Remnants of the Spicer Tornadic Storm Complex
July 14, 2009
4:00pm-11:00pm
Anoka, MNFinally, a severe/tornadic storm system develops within striking range of the Twin Cities and where am I? At the doctor for a physical and going shopping with my brother. I deserve a smack on the back of the head. A moisture tongue shifted over south central Minnesota early on July 14, bringing dewpoints into the mid-60s by early afternoon. The SPC issued a Slight Risk for the southern half of MN, extending southward into Iowa and Missouri, indicating an unusually high threat for tornadoes. This stemmed from the extremely impressive veering wind pattern across the area and strong low-level jet ahead of an advancing short wave/cold front. Ragged cloud cover from a departing system earlier in the day hampered daytime heating across the eastern half of the state, confining temperatures in the low 70s. From my standpoint, whatever storms fired along that boundary (whether it be the cold front or a leftover outflow boundary from the morning storms), regardless of their reflectivity appearance, would be potential tornado producers.
I left work for the doctor shortly before 3:00pm, just as convection began initiating out over far west central MN. Afterwards, I went shopping with my brother and didn't return home until 5:00pm. I was greeted by my weather radio blaring out warnings for central MN counties. I raced downstairs and booted up my machines. I sat there shaking my head as I stared at the multi-storm cluster working it's way across Stearns County, well within my storm chasing range. While numerous tornado warnings where out for these storms, the reflectivity patterns of these storms were not overly impressive. I sat at my desk, debating whether or not to chase these storms (during the height of rush hour). As I read through the storm reports from the afternoon, it was only then that I noticed a number of tornado/damage reports from the town of Spicer in Swift County from an hour before. Online news reports confirmed that a tornado had hit the town of Spicer.
The only storm within my reach was a system bearing down on St. Cloud. The storm had a decent rotation signature on radar, but the reflectivity imagery painted a picture of a storm on the verge of transitioning to a squall line (as seen in the radar images below). As much as I wanted to head out and chase this storm, I withheld myself and figured that the storm was near it's end. Sure enough, within 30 minutes, the storm bowed out and the rotation signature dissipated.
July 14, 2009 6:38pm CDT: Base reflectivity, composite reflectivity, and storm relative velocity radar images of the rotating storm near St. Cloud.
The primary cell cluster merged into a small MCS and tracked across north central MN (Brainerd area), dumping up to 6 inches of rain throughout that area. A squall line--the leading edge of the cold front--developed shortly after 6:00pm CDT and tracked steadily eastward across the state, reaching Anoka County by 9:30pm (radar images below). I went outside and filmed the lightning associated with the approaching storm from my driveway before the rain forced me inside. A total of 0.47 inches of rain fell in a 15 minute time span from this squall line. A video of the lightning show is below.
July 14, 2009 9:30pm CDT: Base reflectivity, composite reflectivity, and storm relative velocity radar images of the squall line nearing Anoka.
