Weather Journal: Sometimes storms spin, even over the Roanoke Valley | Local News

Do you remember the South Roanoke tornado of 2008?

Probably only if you live in South Roanoke, or did some Roanokers did (and I didn’t) on June 3 that year.

A spindly funnel, spawned by a small but potent supercell thunderstorm rolling east-southeast out of West Virginia, caused $ 350,000 damage on 55 properties, including 10 homes, mostly from falling trees. It was rated EF-0 with winds no higher than 80 mph and the intermittent path never wider than 60 yards for 1.4 miles from just northwest of Virginia Western Community College to the Robin Hood Road area.

Roanoke, Salem or Roanoke County.

Tornadoes are blessedly uncommon in the Roanoke Valley. While the mountains do not literally block or deflect tornadoes or supercells (rotating thunderstorms) that are already occurring, the southwest-to-northeast orientation of the Appalachians, partly obstructing the flow of warmth and moisture from the Gulf of Mexico and often trapping more stable on the northeast, and Roanoke’s close to them play roles in the conditions necessary to produce tornadoes being fairly rare.

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It is difficult to get the levels of moisture, shear and instability all at once to spawn a tornado, as cooler, drier on often banks along the eastern slopes of the Appalachians.

Tornadoes tend to be more common west of the Appalachians or farther south and east Virginia and central Virginia where “lee trough” often develops and focuses more favorable severe storm parameters some distance east of the Blue Ridge.

But they have been around for four years. Just since 2018, tornadoes have Craig, Montgomery, Pulaski, Botetourt, Bedford and Franklin counties. Three homes were destroyed in eastern Bedford County 10 days ago

Rotating thunderstorm cells are a little more common. We’ve had two interesting rotating structures over the Roanoke Valley in the last couple of weeks.

On Friday afternoon, May 27, a tight rotation ramped up very quickly, as seen on Doppler radar, in a thunderstorm moving northeast over the Hollins area just northwest of Roanoke.

Torrential rainfall and strong winds At my location south of Roanoke, it was brief rain and a few limb-shaking wind gusts.

On Thursday afternoon, June 2, a visually impressive mesocyclone, akin to what is known as the Great Plains of the central US, passed over the southern part of the Roanoke Valley.

It went right over my location south of Roanoke, but it was not possible to relocate somewhere to see it better. I could get enough of the elephant to know what I was looking at, though.

Fortunately, Luke Barrette of Roanoke got amazing photos of the full structure, looking southwest from the Ballyhack Golf Club east of Roanoke. One such photo is included with this article.

Cloud bases were too high, a result of lower surface dew points, and instability had not been ramped up all that daytime heating, so there was a little tornado risk with this rotating storm structure.

Any storm that rotates can, in theory, produce a tornado.

Living tornadoes in the Roanoke Valley should always have been difficult.

Being living on Kansas or Alabama just doesn’t make sense historically.

I don’t think about the danger of tornadoes locally I did twice in my Roanoke Valley days.

Since the 1890s, there are only five reliable recorded instances of tornadoes hitting Roanoke, Salem or Roanoke County, as shown in the accompanying graphic, with a sixth see probable from historical references.

Only the 1896 Salem storm, known to have caused deaths, only the 1974 tornado from Salem across northwest Roanoke into northern Roanoke County, occurs near the end of the first “Super Outbreak,” produced a ship swath of damage.

In more than a century, there is something that has spun up in the Roanoke Valley, something that has been sporadic. years, could identify it. But, by the same token, we also have the 1953 Starkey storm or the 1899 Norwich storm were in fact tornadoes.

On the flip side, both history and recent events are uncomfortably close proving that tornadoes are not impossible in our valley, and there is no magic barrier that protects metro Roanoke from affecting one, even more serious one than any have had before.

Lynchburg suffered major damage in April 2018 from the EF-3 tornado on the 0 to 5 Enhanced Fujita Scale of tornado intensity, and the April 2019 tornado in southern Franklin County likewise rated EF-3. A Wizard-of-Oz quality funnel barely missed Fincastle on an August day in 2020, while the ground barely made it over Blacksburg without doing so again on the last day of August in 2021.

Climate science does not have a clear projection on whether tornadoes and temperatures are likely to occur, and that it is not always directly linked, and in fact, warming the atmosphere. Some studies point to less frequent but more intense tornado outbreaks.

More menacingly, there is considerable evidence that the nation’s core tornado-producing region has shifted or expanded eastward, closer to us.

Tornadoes are something that the Roanoke and New River valleys should always have, and we should always be prepared to get into the interior of the structure, on the lowest floor, away from windows, if a warning is issued or we otherwise perceive a threat.

But be thankful you don’t live where they are a constant menace. Ducking in the bathroom as you know someone’s subdivision is turning to splinters not far away and yours may be next is no fun.

Weather Journal appears on Wednesdays.

Contact Kevin Myatt at. Follow him on Twitter.


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