Chase Logs 2008
Life in the Cities' Tornado Alley: Multiple Wall Cloud Afternoon
May 31, 2008
4:00pm-9:30pm
Northwestern Twin Cities Metro Area, MNThis past week I started my internship at the Duluth NWS office and drove back home on Friday (May 30) for my brother's graduation party. As I left the office that afternoon I realized that I had only packed my Canon PowerShot digital camera in my backpack, and left the rest of the cameras at my friend's house. I decided not to run back and grab them, hoping that the weather would remain calm during my stay. Well, Mother Nature had other plans. Isn't life wonderful? :)
The SPC issued a slight severe weather risk for southern and central MN due to a passing shortwave feature moving through the state. Thunderstorms began firing along a line from Grand Forks southeastward to Mankato during the mid-afternoon hours, and by 4:00pm I had identified a cell near St. Cloud that was poised to strike Anoka by the dinner hour. The storm became severe just after passing St. Cloud, and as I watched the radar I noted some slight rotation, but nothing too strong and with the cell's size being so small, I disregarded it. But minutes later to my surprise a tornado warning was issued for northern Wright County and at 5:15pm, with the storm located near Becker, I took off on HW 169 south to meet up with the cell.
Left: Storm relative velocity image of the cell as the tornado warning was issued (note the rotation near the Wright and Sherburne County border)
5:21pm CDT May 31, 2008
Right: Base reflectivity image of the tornadic storm 5:29pm CDT May 31, 2008Just after turning onto Ferry (on my way to HW 169) I glanced to my west and saw a very narrow, low cloud extending about three-fourths of the way from the base of the storm. While it was too far away for me to see if it was rotating, it had some nice striations that suggested possible rotation (it could have also been some vertically stacked scud clouds in an updraft, but since radar showed rotation, I'll assume it was a wall cloud). I was not in a position to photograph the cloud, however, and so I booked down Ferry and got out my camera and tried to take a photo of the wall cloud as I crossed HW 10, but as my luck would have it I took the photo just as a fence post crossed in front of the wall cloud (first photo below). My next opportunity came several minutes later as I crossed the Mississippi River. I narrowly managed to capture a decent photo of the wall cloud, but by then it had already started to dissipate (second photo below).
I continued south on HW 169, taking sporadic photos of the dying wall cloud (first and third photos below). I eventually pulled off at a bank at the intersection of HW 169 and 120th Ave. in Champlin and, along with a local police officer, monitored the storm as it passed to the south. It was actually more exciting to watch another storm that had come through a few minutes beforehand as it moved through points east of me (second photo). After enduring some heavy rain showers and watching hail shafts pass to the south (fourth photo), I moseyed on back to Anoka at 6:00pm. I took some random photos on the drive back of a storm to the north and the departing cell to the south in my rear view mirror (fifth photo).
I pulled off at the Anoka County Fairgrounds just south of my house to take photos of the departing storm's structure and a rainbow gracing the southeastern skies (first two photos below). I sat there for fifteen minutes as the storm developed a beautiful anvil coated beneath by mammatus clouds (fourth and fifth photos). Due to the storm's high base I could still see the scud remnants of the wall cloud as it tried to reorganize (third photo), but to no avail. I got back home at 6:30pm and began monitoring the next storm, already darkening the northwest sky.
The core of the second storm passed ten miles to the north at 7:00pm, where it dropped golf ball sized hail on East Bethel and other surrounding communities. Shortly thereafter I ventured outside to watch the storm pass, and noticed an ominous cloud looming just over the treeline to the northeast (first two photos below). I hopped on my brother's bike and pedaled down to the county fairgrounds for a better look at the storm. When I got into a clearing I turned around and was shocked to see yet another wall cloud. There was a small amount of rotation to it, but not much. I snapped a few photos before moving over to the grandstand for a better view of the cloud's base (last three photos below).
But by the time I got up the bleachers, the cloud had moved behind the treeline and all I could see was the the scud trailing the storm. The sirens began screaming for the second time in less than two hours just after I reached the bleachers when other spotters reported a funnel from this cloud closer to the cities. I have a hunch that they may have confused the large amounts of scud under the storm with a funnel (see first two photos below of the scud), but I will never know for sure. I sat there on the bleachers for a few minutes watching the beautiful crepuscular rays to the west (third photo) and the departing storm to the east (last two photos) before I headed back home to track other storms popping up around the cities.
As the 8:00 hour rolled around, I hightailed out to the Anoka High School parking lot for a night of watching storms at sunset. I happened to be at the center of all the action, surrounded by no less then seven different cells (although two were dying and consisted of orphan anvils).
Panoramic View of the Storms looking (from left): NW, NNE, E, SE, and SW (three storms)
My main attention was focused on a developing thunderhead to my northwest, which slowly moved like a curtain in front of the sun, casting ominous shadows on the eastern cells. But the sprawling anvils to the southwest were equally appealing, so I spent the next 45 minutes photographing these two systems. The photos below are organized by storm, starting with the NW cell.
Northwestern Cell 8:14pm-8:25pm
Northeastern Cell (First Three Photos) 8:19pm-8:22pm and the Eastern Cell 8:23pm
Southeastern Cell 8:16pm-8:31pm
Southern Orphan Anvils (2) 8:11pm-8:25pm
Southwestern Thunderheads (2) 8:18pm-8:31pm
Distant Thunderhead to the West 8:28pm-8:38pm
The northwestern cell grew closer as the afternoon waned and by 9:00pm I could clearly see rainshafts filling the northern sky, poised to strike (first row of photos below). With the sunlight fading (but still casting beautiful colors on the southern cells (second row of photos)), I hurriedly snapped a few photos of the approaching rain and the fading pink southern storms before jumping into the car just as the first wave of rain rolled in (third row of photos).
Despite a possible opportunity to photograph lightning, I elected to head back home--220 photos was enough for one day.
