Chase Logs 2007
Thunderscapes
June 20-21, 2007
4:00pm-7:30am
Anoka, Isanti, and Ramsey Counties, MN
It was yet another potential storm chase day and here I was, sitting at my desk at work. I sat there for most of the morning tracking the southward progress of a zonal cold front draped across the midsection of the state, which had prompted the SPC to elevate the severe thunderstorm threat to a slight risk for the area. Convection began firing over in central Wisconsin shortly after noon, but in Minnesota the skies remained clear. But it wasn't long before two cells broke through the cap along the cold front, one in far western Stearns county and the other in northeastern Sherburne county. As these storms neared severe limits the SPC issued Severe Thunderstorm Watch #430 for central and southern MN at 4:25pm CDT. The chase was on. I left work with my mom (carpooling = save money for gas needed on storm chase) within minutes of the watch's issuance and snapped photos of the now severe thunderstorm camped out over Isanti county with my cell phone the whole way home. One of these photos is below.
I wasted no time in packing up the car and heading out shortly after 5:00pm. The Isanti storm had by time tracked southeastward into northeastern Anoka County, but appeared to be on a weakening trend on radar. Hence I set my sights on the western cell, now tracking south of St. Cloud and heading straight for Anoka County. I crawled northward on MN HW 47 in rush hour traffic, finally making it up to Burns Township by 5:25pm. I stopped on the top of a hill in a residential area to photograph the two storms that flanked me to the east and west. Photos 1, 2, and 4 showcase the Stearns County storm, while the other two photos are of the departing storm over NE Anoka County.
Continuing north, I turned off at a vantage point in Nowthen I had used in the past to observe storms. Here I noted that the original storm cell had split in two, with one cell heading southeast towards southern Wright County (photos 3 and 4), and the other continuing eastward into Isanti County (last photo below). The Isanti storm appeared more potent and was closer, hence I chose to intercept that storm.
I cruised through St. Francis and into Isanti County, only to be greeted by a light rain curtain that obscured the storm. With reports of large hail just to the north streaming in over the weather radio, I elected to pull over and observe the southern end of the storm as it passed. Besides light green skies, the storm looked in pretty rough shape. At 6:05pm the NWS issued a tornado warning for the southern cell that I had elected not to chase. Hoping to possibly catch up with the Wright county storm, I pulled out and backtracked to Nowthen to watch the storm. The tornadic storm's base and anvil filled the southwestern skyline (first two photos below), and was too far away for me to catch. Dejected, I moseyed back home to plan out the rest of the night. . .
MPX Radar Data from 5:01pm-6:09pm CDT of the Cells Splitting
I got home at 6:45pm and promptly starred at the radar for half an hour before deciding to move over to the Anoka High School parking lot to watch the departing storms at sunset. I set up shop in the free lot and began taking time lapse video of the tornadic storm as it continued its journey southeastward into Carver county. Trailing the supercell were additional CB towers, each in a different stage of development. It was quite an interesting sight to see (first row of photos below). But this cell wasn't the only thing I was worried about. Behind me to my northwest, additional cells were sprouting up and training in a NW to SE line--right over me (second row of photos). Hardly had I taped for 20 minutes before the first of these storms forced me into the car. Besides brief heavy rain and the distant clap of thunder, the storm amounted to little else.
As this storm cleared I could already see the second CB tower filling in the northwestern skyline. With the Carver county storm fading away and the cells behind it still in the developing stages, I decided to turn my attention to this approaching infant storm (first row of photos below). Half an hour later I once again found myself in the car with my cameras on my lap as this storm tracked overhead. To the south, the cells training behind the original supercell had exploded into supercells as well. For the next hour I taped the development of this system as it went through the final stages of development into a supercell (second row of pictures).
The golden rays of the setting sun coated the western end of the storm in a yellow veil. As the storm matured over the evening, mammatus clouds developed on the underside of the anvil and "sank" down the anvil towards the updraft of the storm, almost as if they were on a conveyer belt. This is especially noticeable on the time lapse video, posted at the bottom of this log.
In addition to this system, two other storms attempted to steal my attention during this timeframe. The second CB cell that passed over my location at 8:20pm weakened shortly after its passage, allowing for several lobes of dissipating convection to spin off from it. One of these lobes drifted southward and developed an anvil, complete with mammatus clouds, before the updraft died. The convection under the cell dissipated within minutes, leaving an orphan anvil stratified across the southeastern sky. This anvil lasted for a good 20 minutes (photos below) before finally succumbing to the environment.
This cell erupted just after it passed overhead, giving me a front row seat to watch its awesome power. The storm was so close that I could just sit and watch the clouds rise over me. I can't say that I've ever seen a storm grow that quickly from that close. The proximity of the storm also meant that I could take stunning close up photos of the cumulonimbus towers (photos below, minus the setting sun). The storm took mere minutes to reach its mature stage.
As the evening waned, the southern supercell complex over the SW Twin Cities continued its southeastward track and became obscured shortly after 9pm as another elevated developing storm passed a few miles to my south (first row of photos below). The now mature eastern cell also began moving away at sunset as a veil of clouds drifted overhead (second photo row).
The fading sunlight provided one last round of entertainment for the night as the eastern storm and the developing rainstorm (which had blocked my view of the southern cell) filled the eastern sky. The cells exploded in pink and dark red coloring, casting an ominous glow across the landscape. The eastern cell began undergoing another round of intensification as the light faded, spurting out tiny C-C lightning bolts. The increasing hoards of mosquitoes, along with yet another impending rainstorm developing to the NW, finally ended my storm chase at 9:30pm.
Or so I thought. The morning of June 21 came quickly since I was planning on carpooling into work with my mom. We left the house at 5:00am and stopped by a nearby gas station. As I was pumping gas, I glanced to the south I couldn't believe my eyes. There, just above the treeline, was the anvil of the storm. Overnight the complex had redeveloped multiple times and eventually merged into one large cell that drifted southward. By the time I saw the storm it was situated near Owatonna, MN, a good 80 miles away. Since I was driving I handed the camera to my mom, who snapped a few photos on the drive into work, including a few nice shots of the storm and the Minneapolis skyline. I dropped her off at work and bolted to a nearby hill, where I took my final photos of the departing anvil. The storm cell dissipated in the late morning hours near the MN/IA border.
It is ironic and fitting that the storm chase should end where it all began, in Arden Hills, 16 hours later.
