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Unique Quality Control Issues
Derek S. ArndtOklahoma Climatological
SurveyJune 25, 2002
Automated QA Flags Decision-making algorithm compiles
results of automated QA tests Final flag (“good”, “suspect”, “warning”
or “bad”) determined by logic The final flag is never final! The Qualparm table represents the QA
Meteorologist’s latest and best assessment of observational quality for the given time
Automated report arrives in the QA Meteorologist’s inbox each morning.
Capturing Real Events With Automated QA Automated QA software is
invaluable as a front-line detector However, nothing beats the trained
eye and brain of a QA meteorologist
Sometimes, unique meteorological events fail QA tests and good data is suggested to be “bad”
Goodparms Goodparms reflect observations
that are known to be good, but have failed an automated QA test
In the next generation of OK Mesonet QA structure, Goodparm entries will override automated QA tests that have been “fooled” by Mother Nature
Noteworthy Goodparm Events The following examples of real
meteorological phenomena that were initially “flagged” by automated QA processes
Thanks to automated reporting, and a vigilant QA Meteorologist, these “bad” events turned out to be some of the network’s gems!
Inversion Poking Extreme spatial anomalies occur
Air temperature Dew point temperature / relative
humidity Wind direction Wind speed
Associated with shallow inversion and stable surface layer
Inversion PokingNorman, OK Sounding
25 Oct 20011200 UTC
Inversion PokingOK Mesonet Sfc Plot
25 Oct 20011330 UTC
Inversion PokingNorth Central OklahomaElevation (meters)
Inversion Poking 26 Oct 19990600 UTC
Cold Air Pooling Extreme temperature anomalies
develop due to radiational cooling Events tend to occur within a few
hours of sunset, suggesting in situ cooling (versus cold air drainage) Radiationally cooled air is prevented
from mixing
Cold Air Pooling 26 Oct 19990600 UTC
Cold Air Pooling East Central OklahomaElevation (meters)
Cold Air Pooling 4 Nov 19991215 UTC
Mesohighs Typically occur concurrently with
convective line or cluster May trigger spatially-oriented QA
tests May be a traveling QA
phenomenon
Mesohighs 1 Jun 19990235 UTC
Mesohighs 1 Jun 19990235 UTC
Mesohighs 1 Jun 19990236 UTC
Mesolows Typically located off the trailing
edge of convective precipitation May be a traveling QA
phenomenon
Mesolows 25 May 20000700 UTC
Mesolows 25 May 20000730 UTC
Mesolows 25 May 20000800 UTC
Mesolows 25 May 20000659 UTC
Mesolows 25 May 20000730 UTC
Mesolows 25 May 20000801 UTC
Heatbursts Originate from air that has subsided
dry-adiabatically from mid-levels of outwardly-innocuous thunderstorms
Downdrafts sometimes cause damaging winds and substantial temperature rises
Heatbursts occur much more often in Oklahoma than previously thought
Heatbursts 20 Sep 19981049 UTC
Heatbursts 20 Sep 19981148 UTC
Heatbursts 20 Sep 19981248 UTC
HeatburstsAir Temperature
20 Sep 19981145 UTC
HeatburstsWind Gusts
20 Sep 19981145 UTC
Heatbursts Mesonet Meteogram20-21 Sep 1998
Winter Precipitation Automated QA is quite good at
detecting wind sensors that accumulate ice and barometers that become sealed from the atmosphere (P ~ T at constant V!)
Unique conditions that accompany snowfall can sometimes lead to erroneous flags
Winter Precipitation Visible Imagery7 Dec 1999
Winter PrecipitationAir Temperature
7 Dec 19991000 UTC
Land-Atmosphere-Vegetation Soil temperatures are sensitive to
the characteristics of the soil and vegetation above them
Vegetation of surrounding land areas can impact temperature and dew point observations at a site
Land-Atmosphere-Vegetation
Land-Atmosphere-Vegetation
Sloshing and Wave Events
That’s It!
Here’s to “bad” data!Best of luck to you and your network!
Derek ArndtOklahoma Climatological Survey
