May 22, 2013

May 22, 2013: Down Days Coming and Early Exit


Thom and I are in Wichita Falls after a day in north-central Texas.  Although there looks to be a supercell-favoring pattern tomorrow (May 23) in northwest TX and the southern TX Panhandle, I've decided to return home with Thom, who has get back due to family issues (good ones, though).

This will be the last active log, and I will now concentrate on trying to get some pictures up for our productive days, mostly May 18 and 19.

I am impressed with the numercial models, particularly the ensembles, which suggested a pattern favorable for supercells in the central Plains almost 10 days in advance.

It turns out that several research projects on tornado formation and evolution were able to get excellent data sets during the last five days.  The Moore, Oklahoma tragedy casts a pall on this.  Nonetheless, we are going to learn much about tornadogenesis because of these couple of projects.  They were not on the Oklahoma City supercell, however, as they were south where most storm spotters and chasers were that day.

I just learned that the tornado we documented near Kinsley, KS has been rated an EF4.   There was no damage (as far as I know) to assess to determine this.  But the Doppler on Wheels (DOWs) were there, and they were able to estimate the wind speed associated with the funnel.  The map above shows the track for the first tornado.   The colors correspond to damage or DOW evidence for a rating.  The red tag shows the position of the tornado when the winds were 165-185 mph.  This corresponds to an EF4 rating.  The radar plot below right shows the DOW plotted radar images at the time the tornado was at maximum strength.   We have pictures and video corresponding to most of the 7 mile damage path for this tornado.

The damaging tornado that struck Moore is still making the news.   I was interviewed via cell phone by KTVU-Channel 2 in Oakland...but I declined other interviews (one from CNN, and directed them to my colleagues who are actually in the Oklahoma City area and who have done refereed research on the previous tornadoes that struck that area.

One reason I don't want to answer specific questions about the Moore tornado is that Thom and I were not there, nor have we assessed the damage.  Several of my colleagues have already been involved in that, and their results already are belying the hyperbole about that tornado (for example, it was not two miles wide, nor did it have a two mile wide damage path.  So far, I've only heard of documentation of damage consistent with an EF4 rating.   But I only get that information hours after the surveys take place.

I'm personally curious what meteorological parameters were in play in the Oklahoma City area that afternoon, that were not in play further south, where most researchers, spotters and chasers were placed.  It's not obvious from the weather data and charts I have for that hour.

Yesterday's Chase

The early runs of the models suggested a few isolated supercells forming around 1PM between Fort Worth and Abilene.  By the time we got into that area, the models were showing none of that, but more of a discontinuous line.  And that's what happened.  We played hopscotch with the rapidly progressing front, trying to stay in the rich moisture ahead of it.

When we got to Waco, several of the cells on the south end of the line became somewhat discrete.  They showed some signs of becoming supercells, but never did.  So, at around 6PM, we called it a chase, and drifted back to Wichita Falls.  Along the way, we changed our plane reservations from Sunday afternoon to tomorrow, Thursday, May 23.

This will be my earliest exit from a storm chase in all my years of chasing.  However, apart from the first day, we've had pretty intense chasing every day of the trip.  Of course, the best and most productive days for documenting tornadoes occurred on May 18 and 19 for us.

Once I have more time to examine our photography and videos for May 18, I will begin posting photo documentation of that day.