I kept a close watch on weather conditions and the radar yesterday – Tuesday Aug 6th – and wound up chasing a good storm as a result.  Neither the SPC or the local Blacksburg NWS office offered hope of severe thunderstorms yesterday but curiously persistent deep layer (0-6 km) shear values over 40 knots and surface-based CAPE (instability) values in the 1500-2000 j/kg range kept my attention.  When a small area of showers developed and sustained themselves over western Bedford county in mid-afternoon my interest was further piqued and I finally headed out the driveway to give chase at 4:15 pm.

By this time the area of showers had pushed slowly into eastern Bedford and Campbell counties so I chose Rte 460 as my egress path.  I paused near the town of Bedford to recheck radar and navigation and realized that continuing east on 460 would send me directly into heavy rain.  Thus I dove south on Rte 122 and maneuvered my way via rural routes (including an unexpected gravel / dirt avenue) to Rte 43.  Taking this road south I turned eastward again on Rte 24 to catch up with the slow-moving storms and did so before reaching the Campbell county line.

Since I didn’t want to plunge into the heavy rainfall (by now a flash flood warning had been issued on this cell) I turned off onto a side road to get a better view of a lowering I had noticed under the storm base.  Parking on the side of another gravel lane I photographed this wall cloud to the east, likely near the Evington area:

5:41 pm

However, the rain shaft on this storm was pushing southward and beginning to impinge on my vantage point so I retreated westward a mile or so and found another rural route that pointed eastward toward Johnson Mountain.  Reaching an intersection marking the end of this road I was faced with the choice of heading northeast into the rain or southwest along the base of the mountain and chose the latter, much to my overall delight as I found another wall cloud building under a cell to the west:

5:57 pm

This cell was clearly rotating both visually and on radar while the wall cloud continued to build.  The surface wind was at my back, being ingested into the storm as it organized:

6:00 pm

 When the rain from this cell began to obscure visibility I pushed further southwest along the base of the mountain and quickly found a convenient church parking lot perched on the mountain’s slope from which to really see the storm:

6:13 pm

 I watched from this location for a few more minutes before the rain again filled in and motored further down the nicely placed county road to another vantage point where I stopped and watched some more.  From this location I videoed the storm as it began to wrap up and visibly rotate (video is sped up 4x, taken at approximately 6:28 pm):

I came very close to calling a report into NWS Blacksburg as the feature at the left center of the video looked a lot like a multi-vortex funnel but it didn’t last long as the cell weakened after another minute or two.

Realizing that if I continued southwestward the storm would escape to the east I chose to leapfrog eastward via Rte 43, crossing to U.S. Route 29 where I once again dove south to avoid rainfall.  I navigated east of 29 and wound up south of Altavista along more rural lanes to catch up with “my” storm:

7:14 pm

As the cell majestically sailed along I was able to get out of the chasemobile at several spots to enjoy the countryside and the view.

7:35 pm

I found one more spot further south and east from which to enjoy the storm as sunset began to darken the sky.  At this point the storm had become outflow dominant (wind in my face) and I abandoned the chase to avoid driving along unfamiliar rural roads after dark.  I should note that at no time during this chase did I see any lightning or hear any thunder.  It seems the cloud tops weren’t high enough for electrification even though the wind shear was sufficient to create rotation.  Great chase!

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