Ticker for January 14, 1999

                
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January 14, 1999   January 14, 1999   January 14, 1999   January 14, 1999


Medicine Park "Inversion Poker" Phenomenon Visits

Throughout the nearly five years of the Oklahoma Mesonet's existence,
there have been several occasions of "inversion poking" by a handful
of stations.  These events are usually nocturnal, and are usually
characterized by warmer temperatures, higher wind speeds, and sometimes
vastly different wind directions, compared to neighboring stations,
as a Mesonet tower protrudes into a layer of the atmosphere not
observed elsewhere in the state.

The vast majority of the significant "inversion poker" events have taken
place at Medicine Park, presumably because the local terrain (the Wichita
Mountains) effects on the lower atmospheric layers.

Take a look at the Mesonet meteograms for Medicine Park (Comanche County,
in southwest Oklahoma) and surrounding stations at the Mesonet subscriber's
data page:

http://www.mesonet.org/


Last night's data shows what could be a mild case of such an event
at Medicine Park.  Notice the wind speeds out of the north between about
1:00 and 5:00 am.  Medicine Park's sustained wind speeds were observed
to be 30-35 MPH through the time period, with gusts into the 40-45 MPH
range.

All of the neighboring stations failed to observe a single five-minute
average wind speed greater than 20 MPH during the time period, with
only a smattering of 20+ gusts (all less than 25 MPH).  Medicine Park
observed all 50 of the 50 strongest wind gusts of the morning.

The winds at 850 mb were from generally the north in the region,
according to this morning's radiosonde data.  It appears that the local
terrain has once again modified the structure of the lower atmosphere
so that the layers above the boundary layer could be observed by the
ten-meter-tall Mesonet station near Medicine Park.

This isn't one of Medicine Park's best performances, however.  Several
events with drastic temperature and wind direction fluctuations have
occurred at the station over the years.