CWOP Wind Data...

I thought I remember seeing a post somewhere in the forum regarding how wind data is reported to CWOP
vs. WU, etc. My wind direction that gets sent to WU is much more consistent (less variance) than what gets
sent to CWOP. I thought this was due to the difference in averaging times (2 min. for WU data and 1 min. for
CWOP)? If this is correct, would it be possible to change this in CWOP to also use a 2 minute average, or at
least to give an option to do so? While seemingly like a small difference, the 2 minute data results in a more
consistent data set, at least the way the AcuRite (18 sec) update gets averaged regarding wind direction. It
would also make it more consistent/comparable among data sets (be it WU, etc). Thanks for any help or
suggestions you can provide. Otherwise, have been using WD for about 4 months now and it is working
awesome now after the bug fixes :slight_smile:

The following is from Fed Met Observer Handbook #1:
5.4.1 Wind Direction. The wind direction shall be determined by averaging the direction over a 2-minute
period. When the wind direction sensor(s) is out of service, at designated stations, the direction may be
estimated by observing the wind cone or tee, movement of twigs, leaves, smoke, etc., or by facing into the
wind in an unsheltered area.
5.4.3 Wind Speed. The wind speed shall be determined by averaging the speed over a 2-minute period.
At designated stations, Table 5-1 shall be used to estimate wind speeds when instruments are out of service
or the wind speed is below the starting speed of the anemometer in use.
5.4.4 Wind Gust. The wind speed data for the most recent 10 minutes shall be examined to evaluate the
occurrence of gusts. Gusts are indicated by rapid fluctuations in wind speed with a variation of 10 knots
or more between peaks and lulls. The speed of a gust shall be the maximum instantaneous wind speed.

I do not see anything in CWOP that would contradict using a 2 min avg. I am hoping Brian can give me some
clarification and at least an option to use 2 min avg wind data if possible. Thanks…

WD sends the last 2 minute average windspeed to CWOP
always has (as that was a requirement of CWOP (note that WD was the first software to send data to CWOP))

Brian,

Here is what I am observing with CWOP compared to 1 minute data log file. I am not seeing any
difference since you changed the wind DIR to 2-min avg in build 31. It is giving same 1 min
output of Wind DIR to CWOP but is sending 2-min Wind SPEED avg to CWOP, based on log file.

log file time wind SPD DIR cwop wind SPD DIR
0006 8.4 080
0007 8.8 011 9 011

0016 10.9 018
0017 9.3 113 10 113

0026 12.3 082
0027 10.8 139 12 139


1436 3.7 282
1437 5.0 286 4 286

1446 3.8 228
1447 0.2 059 2 059

1456 2.1 256
1457 3.2 284 3 284

If the log file is true 1 min data, then I still believe the wind DIR is not
a 2 min avg. to cwop What am I missing? You were certain it always used
2 min data when I first sent message in forum and then you found out it was
not (ie. you believed me). Is it possible, based on what I have shown, that the
change you made is not showing up for some reason (whether on my end or
yours) and cwop is still using 1-min DIR? I can send more examples from before
and after build 31, and I still see no change in output. I want to believe you too,
but do you believe me and what I am seeing? Thanks for any clarification and help
you can provide to explain this or why I am interpreting it wrong.
Thanks…