Review of tornado in high shear, low CAPE environment on 3 May 2010 in Abbeville County, South Carolina

In preparation for our upcoming meeting, I would like to bring a recent event review to your attention.  Back on 3 May, a brief tornado touched down in Abbeville County, South Carolina.  The pre-storm environment was characterized by high shear and low CAPE.  Upon further review of the radar data, the familiar “broken-S” signature was seen in the reflectivity data about 10-15 minutes before tornadogenesis.  What made this case unusual was the relatively short length of the QLCS and the time of year.  That it occurred in May, which is normally thought of as a ‘warm season’ month, is proof that “broken-S” tornadoes are not cool season events, they are HSLC events.  It just so happens that the majority of high shear, low CAPE environments are observed in the cooler months.

Please take a look at:

http://www.erh.noaa.gov/gsp/localdat/cases/2010/3MayAbbevilleCoTornado/BuckStandTornado.html

for more information.

-pat moore

KGSP lowest four elevation slices of base reflectivity at 1235 UTC on 3 May 2010. Elevation angles are 0.5 degrees (upper left), 0.9 degrees (upper right), 1.3 degrees (lower left), and 1.8 degrees (lower right). Images created using GR2Analyst software.

As in previous figure, except at 1243 UTC.

As in top figure, except for 1252 UTC.

As in top figure, except at 1300 UTC. The tornado touched down north of Abbeville at 1303 UTC, near the southern tip of the northern line segment.

Advertisements

About nws-pat moore

B.S. Meteorology, State Univ. of New York - College at Oneonta (1987) M.S. Meteorology, The Florida State University (1996) National Weather Service (12/3/90 to present), stationed at GSP since 8/16/98.
This entry was posted in CSTAR, High Shear Low Cape Severe Wx. Bookmark the permalink.

3 Responses to Review of tornado in high shear, low CAPE environment on 3 May 2010 in Abbeville County, South Carolina

  1. Jonathan Blaes @ WFO RAH says:

    Pat,

    Nice case study. The Palm Sunday tornado event (March 28/29, 2010) in the carolinas was interesting in that it was a HSLC event that featured numerous supercells initially and then the event transitioned to more of a linear/widespread convection scenario. We had an EF-1 tornado in Person County after midnight which was associated with a QLCS. I don’t have a handy radar loop at this point, but may be able to put one together.

    JB

  2. nwspatmoore says:

    JB, Hunter…

    Thanks for your comments. Yes, we have examples of changing convective modes, which makes for a challenging event. We’ve also had events over the western Piedmont where convection will be in the form of a QLCS which then evolves into something more supercellular as it encounters better instability or surface-based buoyancy to the east.

    As for the Palm Sunday 2010 event, while the environment was clearly characterized by high shear and relatively low CAPE, there was something going on over the western Piedmont that organized the storms into more supercellular structures as opposed to a QLCS. We are usually more concerned with the linear modes in an HSLC environment because they give us so much more trouble. We have a good enough grasp on the mini-supercell conceptual model that as long as storms in an HSLC environment show supercell characteristics, we usually do well. The first storm on 28 March gave us trouble because it organized very quickly, but we had the Spencer tornado nailed.

    -pat moore

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s