Early stages of the first storm showed signs of setting up a strong easterly inflow jet. Note the beginning stages of a tail cloud on the northeast quadrant of this extensive cumulus updraft. No precipitation was falling at our location, but an audible roar was heard coming from the east. This sound combined with streamers from the anvil led us to believe large hail was already in progress.
The coverage of my 17 mm wide angle compresses the scene making both storms look small, but they were covering much of the sky at this time. The closest updraft was sporting a tail cloud extending east. No precipitation was seen under the base of the first cell as in a classic LP (low precipitation) structure. The storm further northwest is developing in a more classic manor with rain falling from the north east quadrant of the storm.
LP supercell with an inflow tail cloud. Violent rotation was in
progress at this time in southeast portion for the updraft. This was our view
looking north and the cloud rotation was above and just left of the road. Note
the stacked structure on the eastern side of the concentric updraft. The whole
storm was turning. As the area just north of the circulation crossed highway
#29 golfball hail forced us under the canopy of a large
tree.
A rotating rain curtain swings around the back of the
circulation as the storm turns from LP to a classic supercell. This
configuration would show up on a radar as a "hook echo." Two inch diameter hail
was beginning to fall at our location and tennis ball hail was verified to our
east. This funnel never became planted on the ground, but whisps of
condensation were seen nearing the ground.
The funnel narrows and spins tighter in this image forming a
very narrow needle under
the base that can be seen shooting to ground in a few of our photographs. The
bright backlighting burned out this feature in most of the shots. A second very
narrow rope vortex can
be seen traveling south through the rain curtain. Some of the condensation from
this feature can be seen on the ground and to the right of the funnel. This
funnel made Storm Data as a tornado, although we did not see debris at the
time.
Radar image of second supercell moving into Llano County as first cell weakens. Both storms are shown just to the east of Junction, Texas. The large storm complex to the north may be seen in the background of some of the images. Image courtesy of WeatherTAP.
Supercell number two moving through northern Gillespie County
toward the Enchanted Rock State Natural Area. \Note the twin inflow flanks from
both the west and the south southeast. The area of intense rotation was at the
intersection of these flanks.
We chose to avoid driving under the rotating base structure and approached the storm from the west-southwest. This method was slower, but it allowed us to avoid the golfball to tennis ball haid that fell from both storms. The large red funnel appeared rather suddenly from out of the rain as the setting sun cast light under the storm. The rotation of this vortex was very strong producing a laminar glaze on the side of the funnel to reflect the evening sunlight.
An excellent synoptic study of this day can be found on Lon Curtis' web page. Radar, synoptic maps and satellite are used to look over the situation. Look about half way down the page. His study concentrates on the nearby Bell County supercell seen in the background of some of my shots, but is quite useful in providing data for this case as well.
After looking northeast to witness this dramatic scene the roads became tree shadowed as they twisted through the park area. This blocked the view funnel as it moved southeast and extended very close to the ground. We later learned this became a tornado as it rain wrapped just to our southeast. The only damage it did was to flatten a bunch of trees in the Enchanted Rock area.