Ticker for September 6, 2013

                
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September 6, 2013  September 6, 2013  September 6, 2013  September 6, 2013


El Reno does the limbo

The drier air we've had camped over us recently has made for some deliciously cool
air in the mornings. It almost reminds me of early July! Yeah, strange year. One
station has been doing a particularly fantastic job of cooling at night, making
it stand out from its neighbors. El Reno. For instance, yesterday morning, all
the Mesonet stations around El Reno were in the mid-60s, for the most part, but
there sat El Reno at 59 degrees.



In fact, it dropped to a low of 51 degrees on the fourth. I've had a few folks
e-mail me and ask if those are bad observations, and the answer is an emphatic
"NO!". El Reno is famous for something called "Rapid in situ cooling."

And we all know just how painful that can be.

Basically, what happens is the El Reno Mesonet site undergoes rapid radiative
cooling (i.e., the ground starts emitting longwave radiation, or heat energy,
upwards), the air lay becomes stable, and the warm air above is not able to mix
back to the surface. So that cool layer becomes trapped and therefore the low
temperatures at that location can be quite a bit lower than surrounding stations.
Now I've glossed over the science on this phenomenon quite a bit, because I'll
look stupid if I try to explain it further. But some of my fellow Mesonet
colleagues wrote a paper on the famous El Reno rapid cooling which I'll provide
here.

https://content.mesonet.org/ticker/archive/20130906/elreno-cooling.pdf

So yes, those low temperature readings at El Reno are real.

And they're spectacular! (cue "Seinfeld" exit music)

One final note: ARGH!!



Gary McManus
Associate State Climatologist
Oklahoma Climatological Survey
(405) 325-2253
gmcmanus@mesonet.org