Ticker for December 18, 2001

                
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December 18, 2001  December 18, 2001  December 18, 2001  December 18, 2001


Terrain Influences Morning Evolution

Several of the last few mornings have revealed a little bit about how
the local setting can modify things on the microscale.  Take a look at
northwest Oklahoma in these morning weather maps (from Dec 14th and this
morning):




This week, the Camargo Mesonet station, nestled in the Canadian River
valley in western Dewey County, has reported morning temperatures as
much as 20 F less than nearby Woodward and Cheyenne.  For instance,
at 9:30 this morning, Camargo reported calm winds and a 37 F temperature
while Woodward and Cheyenne were windy and warmer.  On mornings with a
very shallow and very pronounced inversion (i.e., Amarillo this morning:
 ),
subtle differences in terrain can spell huge differences in the time
it takes to erode the inversion layer.

Protected and "deeper" locations (relative to the surrounding terrain)
may take much longer to escape the inversion conditions.  Higher (again,
relative to the surrounding terrain) locations may complete the erosion
of the inversion layer much more quickly.  That's what happened at WOOD
and CHEY this morning and several mornings during the last week.