Ticker for December 13, 2002

                
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December 13, 2002  December 13, 2002  December 13, 2002  December 13, 2002


And We Promise Not to Say "Blanket"

The role of cloud cover on a still winter night was very apparent at
the Hooker Mesonet station the other night.  Check out the highs and
lows in the Panhandle on December 4th:



Where'd that four degree reading at Hooker come from?

Take a look at a time series of the Hooker temperature at 1.5 meters
(brown, because it's closer to the ground), at 9.0 meters (blue, and
closer to the sky) and wind speed (gold, because it's pretty) for
the 48-hour period spanning the 4th and 5th:



Notice the temperature at 1.5m and 9.0m drop from shortly before sunset
on the 4th until midnight.  At midnight, however, the temperature rose
sharply.  Often, we can blame increased winds and mixing for this kind
of overnight warming, but the winds remained light throughout the night!
Sometimes, we can blame a wacky instrument, but the rising action was
observed at both 9.0 meters and 1.5 meters

The culprit was revealed at a nearby ASOS station.  Low clouds
returned at midnight!  These clouds were warmer than the surface (there
was a whopper inversion that night), plus they helped re-radiate the
earth's heat that was lost earlier to clear skies.  So, like a big,
red-hot space heater (except not as hot, and with no electric cord),
they emitted enough energy to make a significant difference at the
surface.

(Thanks to Andy Dean for pointing this event out)


Speaking of Wacky Instruments

A new quality assurance (QA) tool has recently been employed by the
Mesonet's QA manager: the goodparm.

Sometimes, bizarre, microscale, or extreme events get flagged by
the Mesonet's automated QA software.  The goodparm list indicates
those events that were checked out by the Mesonet's QA Manager and
discovered to be real!  This overrides the automatic QA flags and
lets the user know that this seemingly wacky data was an authentic
trick of Mother Nature's.

The benefits of the goodparm table are threefold:

1. It rescues good data from the stigma of QA flagdom
2. It allows automated QA routines to be designed more aggressively,
because a manual override is now available
- and, most importantly -
3. It provides one-stop shopping for folks who enjoy Mother Nature's
extreme bag of tricks!