Ticker for November 4, 2002

                
MESONET TICKER ... MESONET TICKER ... MESONET TICKER ... MESONET TICKER ...
November 4, 2002   November 4, 2002   November 4, 2002   November 4, 2002


Meteograms are Fun!

The cold season is upon us ("cold" as in "not hot", but epidemiologists
in the audience may nod in agreement anyway), and that means meteograms
begin their finest hour - uh, season - as meteorological tools.

Today's all-star meteograms show two processes that typically become
more visible during the cooler months.

At Medicine Park, a pronounced wet-bulbing event occurred shortly after
noon.  The dew point depression at the site shrank from 16 degrees to
just over three in less than an hour!


At Ninnekah, overnight temperatures were highly correlated with wind
speed, demonstrating that mixing, or the lack of it, can play a big
role in determining temperatures:



The Hazards of Being a Mesonet Station

If a Mesonet station could talk, it would tell you that it's no fun
being 33 feet tall and well-grounded during a thunderstorm.  Also,
weather stations need to be distant from any objects rivaling their
height.  This all means Mesonet towers can be pretty darn attractive
to a lightning bolt.  So, despite some highly-effective lightning
protection measures, sometimes fate wins out and a Mesonet station
becomes Mother Nature's personal conductor.

When that happens, coordination between the Mesonet's QA Manager and
a Mesonet technician begins.  It's a process that has matured over
the years to balance the quickest possible response to an "injured"
station, while maintaining satisfactory performance at other stations.

Here are some pictures snapped by Mesonet technician Kris Kesler.
They show the effects of a lightning strike last month at the Eufuala
Mesonet station.  They also show that Mesonet technicians support some
delicate electronics beyond meteorological instrumentation.

The commentary is also Kris's:

"Evidence of arcing between data logger (removed) and the back plane
of the enclosure":


"Damage to ground trace on expansion board.  Repaired on site":


"Damage to traces and relays of the multi-plexer":