Thursday, November 15, 2012

Winter Tornadoes?


I received a very interesting email from meteorologist John Robinson with the National Weather Service office in North Little Rock.

A few months ago, it was thought El Nino conditions would prevail this winter, but that's not likely to pan out.  It's now thought neither El Nino or La Nina will exist.  ENSO Neutral is the state of near-normal climate characterized by neither El Niño nor La Niña conditions.  Simply put, I call it "La Nothing".

John brought to my attention some research from 2 very well respected meteorologists on the possibilities for an active tornado season starting in January through March. Here's the email

"This brings to mind a paper published in 2008 by Ashton Robinson Cook,
a Little Rock native working on a PhD in meteorology at the University
of Oklahoma, and Dr. Joe Schaefer, who was director of the Storm
Prediction Center for many years.  The entire paper can be found on
this SPC Web site:

Their paper shows that we are most likely to have winter tornadoes in
our part of the country when ENSO Neutral conditions prevail.  (Note
that they defined winter as the months of January, February, and

Two of the graphics from the paper are attached.

The first shows tornadoes occurring on “tornado days” during the
winter ENSO Neutral phase (1950 through 2003).  "Tornado days" are
defined as days on which at least 6 tornadoes occurred in the 24-hour
period from Midnight to Midnight.  On average, about 3 "tornado days"
occurred each ENSO Neutral winter.

The second shows tornadoes occurring on “strong and violent tornado
days” during the winter ENSO Neutral phase (1950 through 2003).
"Strong and violent tornado days" are defined as days on which at
least 5 tornadoes of F2 or greater intensity occurred in the 24-hour
period from Midnight to Midnight.  On average, about 1.75 "strong and
violent tornado days" occurred each ENSO Neutral winter."

Does this mean we will have an active tornado season starting in January?  It's tough to say, but based on the research, we better keep an eye on this especially since this year has been so quite.  We definitely don't want complacency. 


The Weather Fanatic said...

It's interesting that the NWS service is going with an above average precip for this winter. I've noticed our rainfall over the last month or so has been quick hitting. We really need a good soaking over the next 3 months and I hope we get it. It does seem that El Nino has died after what appeared to be a fast start in late August through early October.

If slightly warmer than average temps play out, this outlook is plausible. I'm thinking we will have to enjoy our cold snaps when they come and hope the timing is right for snow or sleet, otherwise we are staring at an ice storm which by the way is far overdue for Central Arkansas. I sure hope we don't see a repeat of 12 years ago.

I think if we have any winter at all this year, it will be short lived UNLESS a blocking high over Greenland sets up and the AO stays negative for a few weeks. That would be nice to see a repeat of 2 and 3 years ago wouldn't it?
I remember growing up having near 80 in January and then 20's the next day. You have to get lucky for tornadoes not to accompany. We may not be so lucky this winter since it has been so quiet. Extreme weather is here to stay, so expect the unexpected. Sandy is a prime example.

Snowbird, stay humble and keep expectations low this winter so we can be pleasantly surprised. I am in the warm camp this winter with quick shots of cold. Let's hope it mixes with some snow or sleet.

Michael Bodiak The Weather Fanatic

John Sacrey said...


Excellent blog post. There are 2 minor mistakes you will want to correct. The first being the link to the SPC. If you click on it, it is a email redirect instead. The second is you have "quite" instead of "quiet" in the next to last sentence.

John Sacrey

The NEW Arkansas Weather Blog