Five years since the Ides of March Outbreak

KCLX Level II radar image at 8:29 PM March 15, 2008, as seen through GR2Analyst. A supercell thunderstorm near Moncks Corner had just produced a tornado in the Strawberry neighborhood (between Moncks Corner and Goose Creek) while a forward flank downdraft from a supercell heading over southwest Charleston County was entering downtown Charleston (where I was living at the time). Radar estimated maximum hail size of 1.5 to 2 inches with these storms in addition to intense rotation.

KCLX Level II radar image at 8:29 PM March 15, 2008, as seen through GR2Analyst. A supercell thunderstorm near Moncks Corner had just produced a tornado in the Strawberry neighborhood (between Moncks Corner and Goose Creek) while a forward flank downdraft from a classic supercell heading over southwest Charleston County was entering downtown Charleston (where I was living at the time). While the tornado threat was greatly reduced near the coast, spotters reported quarter-size hail with storms near Johns Island, while baseball-size hail later fell on Hilton Head Island.

Today marks five years since supercells packing tornadoes, strong straight-line winds, and large hail ravaged South Carolina and Georgia in an incredibly unusual atmospheric setup for mid-March known as the Ides of March Tornado Outbreak. (Typically, our most favored time for tornadoes is April and May, according to a National Weather Service research study.)

The March 15 outbreak introduced me to the concept of a Particularly Dangerous Situation Tornado Watch, an enhanced type of severe weather watch more common in the Plains and in Dixie Alley (MS/AL). (Indeed, it was this outbreak which triggered my most intense study into meteorology as well as watch and warning dissemination and spurned on the creation of @chswx a few weeks later.) Here is the archived watch, PDS Tornado Watch 120, at the Storm Prediction Center website.

Three supercells from this event stand out for me: one spawned a EF1 tornado in the Strawberry mobile home community, causing $250,000 in damage and injuring several people (source). It struck a little too close to home for comfort; my parents live just a few miles south of Strawberry in Goose Creek and were very fortunate to dodge that bullet. A second supercell over Hollywood brought very strong winds to where I was living in downtown Charleston at the time — believe it or not, it was the first classic supercell thunderstorm I had ever been in! I didn’t see any hail but the wind was fierce — reminiscent of Hugo videos — with driving heavy rain. On Hilton Head Island, the third supercell produced baseball-size hail at the Hilton Head Airport causing severe damage to aircraft.

In the end, tornado damage up to an EF3 rating was found in several parts of the state (particularly on NWS Columbia’s turf). The Charleston metro area dodged a big bullet as a seabreeze had moved through earlier in the day which helped cut off needed surface-based instability for tornado formation closer to the coast.

Level III image from the afternoon of 3/15/2008 as supercells move through the Midlands of SC.

Level III image from the KCAE WSR-88D captured on the afternoon of 3/15/2008 as supercells moved through the Midlands of SC. (Please excuse the radar branding. Old inside jokes don’t hold up well in historical contexts…)

For more information, including a great technical discussion of the ingredients that led to such a rare outbreak, read NWS Charleston’s summary of the event; I also recommend their research paper (PDF) as it gets really deep into the meteorology. It also explores the challenges of issuing storm-based severe weather warnings in such a widespread severe weather situation (especially since storm-based, polygon warnings had just rolled out).

Fortunately, this March has been very calm and I’m pretty sure we all prefer it that way.