Ticker for January 19, 1999

                
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January 19, 1999   January 19, 1999   January 19, 1999   January 19, 1999

More Overnight Oscillations

Last week, the Ticker looked at several situations which showed remarkable
overnight behavior in the wind field.  Medicine Park gave another
"inversion poking" performance on Wednesday night, and Kenton displayed
a strange, rhythmic oscillation of the wind speed Thursday night.

Take a look at the Norman meteogram from the Subscribers home page:


The Mesonet QA Manager brought this to the Ticker's attention today.
Beginning about 7:00 pm last night, there were no less than four (and
hints of a fifth) quasi-periodic temperature rise-fall couplets,
which show a strong correlation to rise-fall couplets in the wind
speed field.

The temperature rises are probably due to good old-fashioned mixing
from increased turbulence near the surface (a respectable surface
inversion was present in this morning's Norman sounding).

The Oklahoma Mesonet wasn't the only network to pick up the strange
goings-on.  Three OKC-area NWS station also picked up a warming "peak"
in the overnight hours, and the three stations had significantly
differing temperature observations at several times during the night
(at 11 pm, Will Rogers reported 38F, Wiley Post 48F and Tinker 41F).

The fluctuations weren't confined to the Oklahoma City area, though.

Tulsa-area Mesonet stations Haskell and Claremore




seemed to have picked up a significant oscillation of temperature,
also.

All told, this makes three nights in the past week that Oklahoma
Mesonet stations have displayed fascinating wave-like observations
in a shallow, well-defined boundary layer.