November 15 strikes again, again

No, that's not a typo in the title. In 2005 I posted an entry titled "November 15," followed in 2006 by "November 15 strikes again."

So this follows from those.

As I noted in the original entry, November 15 is notorious for having been the date of major severe thunderstorm & tornado outbreaks on three consecutive years in the late 1980s, culminating in the F4 Huntsville tornado in 1989.

Then it happened again in back-to-back years in 2005 with scores of tornadoes including an F4 in Madisonville, KY and in 2006 with widespread wind damage from Mississippi to the Carolinas including injury-producing tornadoes (followed by the deadly Riegelwood, NC tornado around sunrise on the 16th).

Now it's happened yet again, with reports of destructive tornadoes in eastern North Carolina during the wee hours Saturday morning. Kenly is one of the communities that has been hit.

[Kenly, N.C.; AP Photo / Gerry Broome]

This was not a classic standalone supercell -- the tornado formed within a cluster of thunderstorms as part of a line -- but the "velocity" radar image indicated rotation by way of the reds and greens, showing air moving rapidly in different directions and juxtaposed closely to each other.

[Source of radar images: GRLevelX]

This is all a result of a strong cold front interacting with warm, humid air out ahead of it, plus a deep dip in the upper-level jet stream and a strong "low-level jet," with showers and thunderstorms in the Mid-Atlantic and Northeast this afternoon capable of producing additional wind damage and possibly tornadoes.

SATURDAY EVENING ADDENDUM

The University of Wisconsin CIMSS Satellite Blog has a new entry (a cropped image from it is below) which shows that the low-level remnants of Paloma came into the Florida Panhandle early Friday morning and resulted in a big flare-up of thunderstorms with heavy rain and lots of lightning.

Although the large-scale drivers for the North Carolina tornadoes during the wee hours Saturday were the deep trough approaching from the west and unstable air surging northward up the coastal plain on the heels of strengthening low-level winds, the timing and location relative to what happened in the FL Panhandle early Friday had me wondering whether the Paloma remnants were a factor.

An examination of radar imagery shows that the early morning thunderstorms weakened to an area of showers over Georgia during midday Friday and then dissipated as they later moved into South Carolina, while new clusters of showers and thunderstorms developed over the Florida Panhandle and south Georgia and combined with those associated with an impulse from Alabama.

That's the stuff which later moved into North Carolina and got out of hand, and it was solidly in the warm, humid air well ahead of the cold front. And the CIMSS animation of low-level spin in the atmosphere showed a maximum in the Carolinas out ahead of the main trough, at least some of which appears to have been injected from the Gulf.

So while Paloma's remnants certainly didn't singlehandedly cause the rash of tornadoes, perhaps their last vestiges played a role?

If nothing else, it's an interesting coincidence ...

Meanwhile, no tornadoes reported yet today despite all the watches which were issued, but there has been wind damage in a few places from Virginia to New England, and in New Jersey unfortunately a man was killed when a tree fell on him.