Backyard Chase... sort of... 10/24/10

This was a rather unexpected event.

Well... not entirely unexpected... The Storm Prediction Center did have a slight risk across East Texas into Arkansas and Louisiana. I also had reasoned that if the Dry Line did not cross I 35 by late evening then things might be real interesting. But, when the first few storms fired in East Texas and Louisiana I kind of wrote off the event thinking the best lift had already passed well east of our area. But I was wrong...

The Dry Line did not push east of I 35 until evening (if it ever actually did) and was set up right along I 35 by  4pm. We had very high instability with very strong shear over much of North and East Texas when storms fired right along it. The result of all this was a pretty major severe weather outbreak from I 35 eastward with at least a couple tornadoes (one of which impacted the city of Rice and caused significant damage there).

It was about 4pm that I began to notice a change in the sky over Collin County and that something was indeed going to happen. Towering cumulus began to erupt everywhere (and I mean erupt)... especially just to my southwest. It was pretty clear that major storms were trying to form because the exploding upward motions in the clouds was quite pronounced. There have only been a couple of times that I can remember seeing such violent upward motions to towering cumulus, and each one of those times yielded very intense storms.

The first reflectivity that appeared in Collin County was on the far southwest side. Since all the activity was moving northeast I figured my best bet was to jump on 78 and get to Farmersville as quickly as possible. As soon as I left James Langford was able to keep an eye on the radar for me and nowcast. (I did have radar, but since I spent a lot of my time driving I couldn't keep such a close eye on things.) The cell that I had targeted intensified at an alarming rate and quickly became severe. Once it had reached 380 near McKinney it took a hard right turn and began to move straight east. I made it as far as county road 550 north of the last branch of Lake Lavon that 78 crosses when I suspected that the storm was too close for comfort. To make things more interesting new cells were continually firing on the main storms flanking line where they would quickly be ingested by the main cell.

At this time the cell had been showing supercellular characteristics with some striations trying to become visible in the sides of the updraft tower (though never very pronounced), the development of a vault area, and a large rain free base to the south of the heaviest precipitation.

 Since new cells were continually firing straight west of me and being drawn into the main cell and since the main cell was now moving straight east while getting bigger all the time, I decided to head back south and not drive all the way to Farmersville. I thought at this point that maybe I should give up the pursuit of this cell since it had more or less beaten me to Farmersville, but James insisted that if I went straight to Greenville and get on I 30 I might be able to stay a head of the cell. So, I headed back south to FM 6 and took it northeast towards Greenville. At this point the supercell was beginning too look very outflow dominate and had gotten huge, practically taking up an entire county in size. As I headed into Greenville I drove underneath a mean looking gust front and experienced some heavy rain and wind.

Once I reached I 30 I was able to get out ahead of the storm again... but the whole time the storm was picking up speed and I was leaving the treeless landscape and heading into the woods of East Texas where the view of the sky becomes very narrow on the highway. James then informs me that new cells along the supercells flanking line were beginning to rapidly intensify and that I would soon have a more solid line of storms on my tail rather than just one big cell paralleling I 30. So I decided to quickly pull over at the nearest exist, grab a few pictures, and then punch back through the storm  to the other side before the new supercell to my southwest overtook me. By this point I was probably about 10 miles or so west of Sulpher Springs on I 30.

The lighting under the storm base was pretty much perfect. The underside of the gust front was very turbulent and choppy... the sign of a storm being dominated by strong outflow.

 

James stitched this panorama for me since I didn't have the software to do it. It's also a pretty compressed version in order to get it online. And yes that is half a truck in the foreground!

 I headed back west on I 30 without running into too much rain until I reached another decent viewing area on Paterson Street just north of I 30 and very near the town of Campbell. By the time I reached this spot James informed me that the storm that would've originally overtaken me had gone tornado warned along with the bigger storm to the north of I 30 (which was now north of Sulpher Springs). Not really sure how much danger I would've really been in but giving up the chase on these storms sure seemed to be the right choice. 

The rest of the pictures I took were at the turnout for Paterson Street (FM 513) as it had the only decent viewing for miles and storms kept firing to my south-southwest and training off to my east. During this time the Rice Texas Tornado took place and James Langford eventually joined me east of Greenville to shoot lightning.

This towering Cumulus exploded into a full thunderstorm rather quickly. The motion was quite amazing and comparable (in my mind) to an erupting volcano. 

This storm did not live particularly long, but a new one developed right where it originally had and with the same ferocity. The new one quickly became severe as it passed to my southeast and was even tornado warned. 

Verticle Panorama since it was too close and too large to get in one frame. The top part of the panorama is actually directly overhead.

By the time James joined me the sun had set and we shot lightning for a good hour or more. New storms fired way to the southeast of Dallas near Corsicana and, despite being so far away, we had a vivid lightning display.

They were probably the most electrically active storms I had ever seen since the Paris storm from April 3rd 2008. 

In the end I had over 400 images to edit and still have a ton more to go through. 

Again... Thanks James for the nowcasting!