[wxqc] Weather data quality report for 2005-01-16 and 2005-01-17
Harold Lemon
hlemon22 at mindspring.com
Wed Jan 26 23:25:56 EST 2005
Dave,
Thanks for the suggestion. I did look over some of the different shields and I
may have to go that route if relocating the sensor doesn't work. But yes, I'll
agree that it is currently in a poor location with too much humidity and not
enough air circulation. I could ask Peet Bros. and see if they offer the shield
by itself. The plastic bowl shield sounds easy enough to make. Would you
happen to know if the Davis shield will fit any sensor or only Davis sensors?
----- Original Message -----
From: "Sandy and David Helms" <dshelms at comcast.net>
To: "Discussion of data quality issues" <wxqc at lists.gladstonefamily.net>
Sent: Monday, January 24, 2005 10:52 PM
Subject: RE: [wxqc] Weather data quality report for 2005-01-16 and 2005-01-17
Harold,
You might want to try one of the home brew solutions listed on Russ'
"Radiation Shields" web page:
http://www.wxqa.com/shields.html
I definitely encourage everyone to properly shield their temperature sensor
probe as even indirect sunlight will cause abnormally high measurements (use
plastic for the shield material as it is a poor absorber/emitter of solar
radiation). In addition to shielding, the sensor should be in a well
ventilated area on a post at 1.5 meters or 5 feet above ground on a ground
cover that is natural and representative for the surrounding area (cement is
not a natural ground cover).
Here's a example of a commercial passive radiation shield product, which is
advertised for just only $50:
http://www.provantage.com/buy-7davs008-radiation-shield-w-passive-airflow-te
mperature-humidity-sensor-davis-instruments-optional-accessories-weather-sta
tions-7714-shopping.htm
Hope this helps,
Dave
CW0351
-----Original Message-----
From: wxqc-bounces at lists.gladstonefamily.net
[mailto:wxqc-bounces at lists.gladstonefamily.net]On Behalf Of Harold Lemon
Sent: Wednesday, January 19, 2005 12:39 AM
To: Discussion of data quality issues
Subject: Re: [wxqc] Weather data quality report for 2005-01-16 and
2005-01-17
Evan,
Thanks a lot for the explanation. I'm glad to know that some of my data was
acceptable. My station is a Peet Bros. Ultimeter 2100 with their outdoor
temp/humidity sensor, no shielding, and no fan aspiration. To protect it
from
the sun, wind, and rain, the best place I could find was on the north side
of
the house under the patio cover mounted about a foot from the bottom of the
cover. The patio is cement. We have had a lot of rain here lately so there
is
a lot of moisture around that part of the house and probably to make matters
worse, I'm about 150 feet from a small creek. About the only thing I can
try to
do is move the sensor to another location which may not be as protected or
get a
sensor that's shielded.
Thanks again for your help.
Harold
----- Original Message -----
From: "Evan Bookbinder" <Evan.Bookbinder at noaa.gov>
To: "Discussion of data quality issues" <wxqc at lists.gladstonefamily.net>
Sent: Tuesday, January 18, 2005 6:52 AM
Subject: Re: [wxqc] Weather data quality report for 2005-01-16 and
2005-01-17
Harold, note that the barometer reading in the report is rounded to the
nearest whole millibar. Your numbers are WELL within tolerance.
Absolutely nothing to worry about. My concern with the FSL QC routine is
whether that millibar conversion is just a straight inches of mercury to
millibar converstion or if it's actually using temperatures to calculate
true "sea level pressure" as the NWS uses. This could also explain the
small degree of error you are seeing, but as a whole, it looks great.
Your dewpoint sensor definitely is having problems (which of course
plays directly into relative humidity). Your error is averaging -6 to
-7, meaning that your dewpoint is running much too warm. So I have
several questions for you...what manufacturer of instrument do you have?
where is the instrument sited on your property and what type of
vegetation/etc...is beneath it? Does your temperature/dewpoint set have
a fan aspiration? I'm concerned here because there are a number of "bad"
weather stations on the market that I really would not recommend to
weather hobbyists or professionals and the quality isn't sufficient for
your own needs, let alone the CWOP network. 6-7 degree errors on the
dewpoint are of course unacceptable, and usually there's little to blame
outside of pure instrument error/design with that measurement, but I'm
curious to see what you've got going on.
As for your winds, they appear to be light and variable (generally < 5
mph). The QC report would really only be of assett on a day where
everyone has a steady wind (say west at 10-15 mph) and true errors can
be noted.
Evan
----- Original Message ----- From: "Harold Lemon" <hlemon22 at mindspring.com>
To: <wxqc at lists.gladstonefamily.net>
Sent: Tuesday, January 18, 2005 1:50 AM
Subject: [wxqc] Fw: Weather data quality report for 2005-01-16 and
2005-01-17
I would appreciate it if someone could tell me what is going on with my
station.
I have included the reports below for 01-16-2005 and 01-17-2005. I
compared the
barometer readings with OAK, SFO, SJO, and HWD and don't appear to be
more than
.02 or .03 inches difference between them most of the time. I know I
have a
problem with dewpoint. The humidity is always about 20% higher than
everyone
else around me but, don't know if it is a problem with the sensor or
where it's
located. Where the wind is concerned, I calibrated the sensor with a
compass so
I don't understand why this is showing up in error.
Also, I am at 10 ft. elevation and set my barometer with HWD which is at
46 ft.
elevation. If their barometric pressure is at 30.30 in., should it be
the same
for my location or do I need to adjust it differently?
Any help would be appreciated. Thanks.
Harold
----- Original Message ----- From: "Weather Quality"
<weather-qc at nospam.gladstonefamily.net>
To: <hlemon22 at mindspring.com>
Sent: Sunday, January 16, 2005 6:05 PM
Subject: Weather data quality report for 2005-01-16
DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF
* (MB) * (DEG F) * (DEG F) * (DEG) *
(KNT)
16-JAN-2005 0016 CW3109 *1027(0.06)* 52(-1.5)*48.9(-8.1)* 304(
129)*5.21(-3.1)
16-JAN-2005 0101 CW3109 *1027(-0.0)* 51(-2.6)*48.5(-7.1)* 289(
135)*0.87(
1.2)
16-JAN-2005 0116 CW3109 *1028(-0.3)* 51(-2.6)*48.8(-7.4)* 0(81.2)*
0(2.07)
16-JAN-2005 0131 CW3109 *1028(-0.3)* 51(-2.6)* 49(-7.7)* 0(81.2)*
0(2.07)
16-JAN-2005 0146 CW3109 *1028(-0.6)* 50(-1.6)*48.3(-6.9)* 0(81.2)*
0(2.07)
16-JAN-2005 0201 CW3109 *1028(-0.5)* 50(-3.4)*48.6(-7.6)* 0(41.1)* 0(
1.8)
16-JAN-2005 0216 CW3109 *1028(-0.6)* 50(-3.4)*48.6(-7.6)* 0(41.1)* 0(
1.8)
16-JAN-2005 0231 CW3109 *1028(-0.4)* 50(-3.4)*49.2(-8.1)* 0(41.1)* 0(
1.8)
16-JAN-2005 0246 CW3109 *1028(-0.3)* 49(-2.4)*47.9(-6.8)* 0(41.1)* 0(
1.8)
16-JAN-2005 0300 CW3109 *1028(-0.2)* 49(-3.5)*48.2(-6.6)* 0( 75)*
0(1.16)
16-JAN-2005 0315 CW3109 *1028(-0.2)* 49(-3.5)*47.9(-6.8)* 0( 75)*
0(1.16)
16-JAN-2005 0331 CW3109 *1028(-0.3)* 48(-2.5)*47.2( -6)* 0( 75)*
0(1.16)
16-JAN-2005 0345 CW3109 *1028(-0.5)* 48(-2.5)*47.2( -6)* 0( 75)*
0(1.16)
16-JAN-2005 1816 CW3109 *1030(-0.3)* 48(0.09)*47.5(-6.6)*
262(-136)*2.61(-1.4)
16-JAN-2005 1846 CW3109 *1030(-0.5)* 49(-0.9)*47.9( -7)*
278(-152)*6.08(-4.9)
16-JAN-2005 1901 CW3109 *1030(-0.3)* 50(1.61)*48.6(-7.8)* 253(
177)*4.34(-2.9)
16-JAN-2005 1916 CW3109 *1030(-0.2)* 51(0.61)*49.3(-8.5)* 303(
127)*1.74(-0.2)
16-JAN-2005 1931 CW3109 *1030(0.01)* 51(0.61)* 49(-8.2)*
191(-121)*2.61(-1.1)
16-JAN-2005 1946 CW3109 *1029(0.21)* 52(-0.4)*49.5(-8.6)*
183(-113)*2.61(-1.1)
16-JAN-2005 2001 CW3109 *1029(-0.0)* 53(1.11)*50.1(-8.5)*
210(55.7)*2.61(-0.2)
16-JAN-2005 2015 CW3109 *1029(0.35)* 54(0.11)*50.5(-8.9)*
189(76.7)*4.34(-1.9)
16-JAN-2005 2031 CW3109 *1028(0.72)* 54(0.11)*49.9(-8.2)*
176(89.7)*1.74(
0.7)
16-JAN-2005 2100 CW3109 *1028(-0.5)* 55(0.99)*50.2(-7.9)*
313( -38)*4.34(-2.3)
16-JAN-2005 2116 CW3109 *1028(-0.0)* 55(0.99)*50.2(-7.9)*
232(43.5)*0.87(1.19)
16-JAN-2005 2130 CW3109 *1028(0.16)* 56(-0.0)*50.9(-8.5)*
339( -64)*4.34(-2.3)
16-JAN-2005 2145 CW3109 *1027(0.61)* 56(-0.0)*50.6(-8.2)*
282(-6.5)*4.34(-2.3)
16-JAN-2005 2200 CW3109 *1027(-0.2)* 56( 1.7)*50.6( -8)*
329( -22)*2.61(-1.1)
16-JAN-2005 2216 CW3109 *1027(0.03)* 57( 0.7)*51.2(-8.6)*
327( -20)*4.34(-2.9)
16-JAN-2005 2231 CW3109 *1027(0.03)* 56(1.09)*49.9(-7.3)*
312(-4.8)*5.21(-3.8)
16-JAN-2005 2246 CW3109 *1027(-0.2)* 57(0.09)*51.2(-8.6)*
321( -14)*5.21(-3.8)
16-JAN-2005 2300 CW3109 *1027(-0.4)* 57(0.75)*50.9(-6.9)*
333(18.3)*1.74(0.65)
16-JAN-2005 2316 CW3109 *1027(-0.2)* 57(0.75)*50.5(-6.8)*
39(12.3)*4.34( -2)
16-JAN-2005 2330 CW3109 *1027(-0.0)* 57(0.75)*50.5(-6.8)*
338(13.3)*1.74(0.65)
16-JAN-2005 2345 CW3109 *1027(-0.0)* 57(0.75)*50.2(-6.4)*
14(37.3)*4.34( -2)
16-JAN-2005 Smry CW3109 *-0.3(0.33)*-2.1(
1.7)*-5.9(1.54)*69.6(77.3)*0.76(
1.7)
Note that times are in UTC. The values displayed are 'Observed (error)'
The error value is 'analysis - observed'. I.e. if your observed value is
higher
than the computed value, then the error will be negative. You have to
pick out
the reading that is in error. The row with the time of 'Smry' is a daily
summary
and the data is 'mean(standard deviation)' for each observation during
that
day.
Graphs:
http://pond.gladstonefamily.net/cgi-bin/wxqchart.pl?date=20050117&site=C3109
For more information about quality checking, then visit
http://www.wxqa.com/
To discuss, sign up to WXQC at
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To stop this email, just click the link
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83
Subject: Weather data quality report for 2005-01-17
DATE UTC SITE * ALT * POT TEMP * DEW PNT * DD * FF
* (MB) * (DEG F) * (DEG F) * (DEG) *
(KNT)
16-JAN-2005 2345 CW3109 *1027(-0.1)* 57(-0.2)*50.2(-6.6)*
314(46.9)*4.34(-2.5)
17-JAN-2005 0001 CW3109 *1027(-0.2)* 57(-0.2)*50.5(-6.9)*
271(89.9)*5.21(-3.3)
17-JAN-2005 0016 CW3109 *1027(-0.2)* 57(-0.2)*50.9( -7)*
326(34.9)*4.34(-2.5)
17-JAN-2005 0031 CW3109 *1027(-0.2)* 56(0.79)*50.6(-6.7)*
283(77.9)*4.34(-2.5)
17-JAN-2005 0046 CW3109 *1027(-0.3)* 56(0.79)*50.9( -7)*
278(82.9)*2.61(-0.7)
17-JAN-2005 0101 CW3109 *1027(-0.5)* 56(-1.4)*51.2(-7.1)* 216(
158)*1.74(-0.6)
17-JAN-2005 0116 CW3109 *1027(-0.5)* 55(-0.4)*50.9(-6.7)* 0(31.1)*
0(1.12)
17-JAN-2005 0146 CW3109 *1027(0.02)* 54(0.59)*51.1( -7)* 0(31.1)*
0(1.12)
17-JAN-2005 0201 CW3109 *1027(-0.3)* 54(-2.7)*50.8(-6.8)* 0(79.6)*
0(0.68)
17-JAN-2005 0246 CW3109 *1027(-0.5)* 52(-0.7)*50.3(-6.3)* 0(79.6)*
0(0.68)
17-JAN-2005 0300 CW3109 *1027(-0.5)* 52(-1.5)*49.8(-6.3)* 0( 148)*
0(0.79)
17-JAN-2005 0316 CW3109 *1027(-0.6)* 52(-1.5)* 50(-6.6)* 0( 148)*
0(0.79)
17-JAN-2005 0331 CW3109 *1027(-0.8)* 52(-1.5)*50.3(-6.9)* 0( 148)*
0(0.79)
17-JAN-2005 0346 CW3109 *1027(-0.7)* 51(-0.5)*49.6(-6.2)* 0( 148)*
0(0.79)
17-JAN-2005 2100 CW3109 *1026(-0.7)* 57(-0.9)*53.5(-6.2)*
217(97.9)*1.74(-0.3)
17-JAN-2005 2115 CW3109 *1026(-0.0)* 58( -2)*53.8(-6.5)*
226(88.9)*1.74(-0.3)
17-JAN-2005 2131 CW3109 *1026(0.28)* 59( -3)*54.2(-6.8)*
282(32.9)*4.34(-2.9)
17-JAN-2005 2145 CW3109 *1026(0.52)* 59(-3.1)*53.8(-6.6)*
295(19.9)*4.34(-2.9)
17-JAN-2005 2201 CW3109 *1026(-0.6)* 59(-1.9)*54.8(-7.1)*
327(-0.9)*5.21(-2.4)
17-JAN-2005 2215 CW3109 *1026(-0.7)* 58(-0.9)*54.5(-6.9)*
323(3.12)*6.95(-4.1)
17-JAN-2005 2231 CW3109 *1026(-0.7)* 58(-0.9)*54.5(-6.9)*
303(23.1)*4.34(-1.5)
17-JAN-2005 2245 CW3109 *1026(-0.7)* 58(-0.9)*53.8(-6.3)*
294(32.1)*5.21(-2.4)
17-JAN-2005 2301 CW3109 *1026(-0.6)* 58(-2.1)*54.8(-7.5)*
316(7.25)*5.21(-1.7)
17-JAN-2005 2316 CW3109 *1026(-0.4)* 58(-2.1)*55.1(-7.8)*
353( -40)*4.34(-0.5)
17-JAN-2005 2331 CW3109 *1026(-0.3)* 58(-2.1)*54.8(-7.5)*
330( -17)*4.34(-0.5)
17-JAN-2005 2346 CW3109 *1026(-0.3)* 58(-2.1)*55.1(-7.7)* 312(
1.4)*1.74(2.08)
17-JAN-2005 Smry CW3109 *-0.4( 0.3)*-1.3(1.01)*-4.8(1.84)* 23(
112)*0.07(1.33)
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