1. Quality checking results and discussion by e-mail
Philip, CW0003, operates an on-line analysis and display system of the MADIS quality checking results for registered CWOP stations. In addition to on-line displays and lists, he can send you a summary of your quality checking results by e-mail if you sign up below.
- On-line sign-up form
- Site meta data - use 5 character ID
- Average performance of CWOP stations - use 5 character ID
- Individual station quality checking
- Equipment types in use
- Summary checks
- CWOP Barometer Miscalibration Report
- CWOP Altitude/Location Error Page
- Registered vs USGS Elevations
- Stuck Station Report
- Add Pictures of your Station
Philip has also set-up an e-mail reflector discussion list for CWOP quality checking. To join this list, send an e-mail to "wxqc-subscribe@lists.gladstonefamily.net" (without the quotes). This list will build up an archive that should contain a lot of pertinent information on the CWOP quality checking.
2. Hourly Quality Checking Results
Compressed files of the Hourly QC Results for the day previous to that in the filename are available. If you download and ungzip one of these, there are numbers for the different hourly observations. The number outside the parenthesis is the difference between the QC analysis and the observation. Negative means that the observation is greater (warmer) and positive means the observation is less (cooler) than the analysis. The number inside the parethesis is the threshold to declare a questionable observation (max five per hour).
The uncompressed files are not suited to viewing single station results, so here is a way to view hourly results for a particular station. Enter a start (the previous 15 days are available) and end date (current UTC day is the latest) and your 5 character NWS ID into the form below (don't use CWxxxx, use Cxxxx). The year must have four numbers. After an interval dependent delay, you will receive a list of the number of questional observations (max five per hr) for each hour of each day that quality checking results were available. You will also receive tables of the averages and standard deviations (rms) of the differences between your questionable observations and the analysis. Since standard deviation is undefined for a single difference, "one" indicates only one difference in the set.
These results can be used for close examination of the station response during the times when the atmosphere is coolest or warmest (under normal conditions). For example, if the temperature differences are positive and occur early in the morning when the atmosphere is the coolest, it may be that you are in a low area where cold air settles and this area of cold air is too small to be represented by the interpolated value. Another example is in the afternoon, during the time when the solar heating is the greatest. If your station has differences that are negative numbers, it may indicate the temperature transducer has solar heating, making false warm readings. Then you need to improve your radiation shielding. Look at Radiation Shields for ideas.
Another approach is to look the hourly results for stretches of days for which there was no changing weather, i.e. a constant weather regime. Then note if there are more questionable observations for different weather regimes.
3. Quality Checking Summary Information
Current quality checking summaries for CWOP stations in the USA can be seen at QC Summary Messages. These summary files provide quality checking information for each station over hourly, daily, weekly and monthly time scales. The Summary Message Description explains the format and tells how to interpret the summary messages. The QCMS Overall Description tells how each each of these quality checking procedures are done and how the summary files are produced.
4. Daily Quality Checking Results
These are stored versions of the Daily QC Summary Infomation from number 1 above. They cover 0000 to 2359 UTC for the day previous to the compilation date indicated in the file name. These files allow you to look back in time and see if your station had similar results in the past. There is always a lot of variation in weather related items. So, when evaluating your weather station, don't just look at a single day. Look over many days and see if there are patterns.
| Page generated on Aug 1, 2006. Site maintained by Russ Chadwick, KB0TVJ. Send any comments to russ@wxqa.com. |
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