Grensburg Tornado Environment Analysis By Jon Davies

[Shawna Davies]

Jon Davies did an analysis on the Greensburg tornado environment if anyone is interested. Here's the link:

http://members.cox.net/jondavies6/050407greensburg/050407greensburg.htm

Shawna Helt

MOD: Corrected link address

 

[Jason McKittrick]

Maybe it's just my computer, but your link doesn't seem to work.

 

[Josh Richardson]

It worked for me just fine...

 

[Craig Maire II]

Sorry but it doesn't work for me either?

 

[Dan Cook]

fine here as well.

 

[Andy Wehrle]

If it doesn't work for you take two of the / out of the http:////

 

[Scott Olson]

As always Jon does a good job of summarizing the environment. I noticed the same thing with the RUC soundings I've been looking at, the model looks way to dry for the beginning period. The RUC also appears to underdo 0-1km SRH a bit as the 3hr NAM graphical map shows 350 m2/s2 centered over the storm. This is also consistent with the 300 m2/s2 shown on SPC mesoanalysis and what I'm assuming was calculated 400 m2/s2 via the Haviland profiler. That profiler really has winds kicking up 45-50kts in the lowest 500m in the 10 o'clock hour.

Those strong increasing low level winds and strong moisture advection helped keep the boundary layer well mixed and the CINH stayed quite neglibile. So the normal problems that would apply at night didn't materialize here and the favorable environment was there for the taking.

Storm motion Bunkers vs. Obs:


That's quite a wild ride there. I've seen several other comparsions of cyclic supercells and usually it's bunkers, right, bunkers, right. The surge/retreating of the gust front and propogational component with multiple strong mesocyclones make for a complicated motion. The radar loop is very interesting as is the tornado track for the Greensburg tornado. The left turn conincides with the end portion of the Greensburg cell and than as expected the next cycle resumes a more right track and slower forward (14kts) speed. Also, it's worth noting that about 3/4 of the low level helicity was confined to the 0-1km layer and very close to the surface.

I've posted a little bit of more thoughts on my blog but I think Jon has covered it very well.

 

[rdale]

Correct link:

http://members.cox.net/jondavies6/050407greensburg/050407greensburg.htm

 

[Brandon Sullivan]

WOW! What a great analysis... Great Job!

 

[Bobby Prentice]

Haviland, Kansas wind profiler data

The Haviland, KS wind profiler was in excellent position to sample the Greensburg storm inflow environment.

FSL real-time (and archived) profiler data display

Haviland, KS Wind Profiler 60-minute data, 5/4/2007 16z - 5/5/2007 03z (800x550)

Haviland, KS Wind Profiler 6-minute data, 5/5/2007 0154z - 5/5/2007 0300z (800x550)

Haviland, KS Wind Profiler 6-minute data, 5/4/2007 2254z - 5/5/2007 0300z (1200x1500)

I believe the Haviland profiler also reports surface observations, but I do not know where to find the data.

Perhaps the primary reason the RUC (and, thus, SPC mesoanalysis) was so dry in the Greensburg area was because of an obviously too dry (faulty) Haviland surface dew point? If I remember correctly, the RUC does ingest mesonet temps/dew points, but not winds. The RUC should have ingested the Haviland wind profiler data.

 

[Eric Flescher]

wow that analysis was just what I was looking for

This analysis is done amazingly well. Thanks for posting.

***

Jon Davies did an analysis on the Greensburg tornado environment if anyone is interested. Here's the link:

http://members.cox.net/jondavies6/050407greensburg/050407greensburg.htm

Shawna Helt

MOD: Corrected link address