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Old 09-17-2013, 10:33 PM
 
Location: Vernon, British Columbia
3,018 posts, read 2,517,775 times
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I've noticed quite a few errors in the Environment Canada database, many of which are purported as fact when they are, in fact, clearly wrong. I will start with two obvious ones, and follow up with more later.

1) North West River, Newfoundland & labrador, is apparently the hottest temperature ever recorded in that province at 41.7C (107F). This is wrong for several reasons. First, the day before and the day after this data (August 11, 1914) were only 65F. That's right, the temperature jumps 42 degrees, then just as suddenly drops 42 degrees. Meanwhile, the overnight lows stayed about the same (~50F). Second it rained that day, and there is no way the temperature could vary that much in wet weather. Third extreme heatwaves do not occur on single days; the heat builds over several days. And fourth, the second hottest place in Newfoundland that month couldn't eve break 80F.

I suspect that the actual temperature as 67, but someone misread it as 107.

2) Grand Forks, BC, was 25C (77F) on December 4th, 1943, according to Environment Canada. This cannot be the case anywhere in Canada in December as I'm sure you would all agree to be so.


Other countries have similar problems with their records, so here is the place to tell us about them.
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Old 09-17-2013, 11:09 PM
 
Location: Saskatoon
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Quote:
Originally Posted by Glacierx View Post
2) Grand Forks, BC, was 25C (77F) on December 4th, 1943, according to Environment Canada. This cannot be the case anywhere in Canada in December as I'm sure you would all agree to be so.
I don't agree. While 25 in December is certainly extremely uncommon and hasn't been recorded in most parts of Canada, that doesn't mean that it could never be and that the Grand Forks record is inherently wrong. The day before was 17.2 and the day before that was 14.4, considering that Grand Forks has an average high of only -1 in December and that it has a dry climate which allows for great deviations from average, I'd say it's a reasonable (albeit rare) record.

Do you have any evidence or sources that the record is wrong? Your first point had some good logic and analysis to it but this one just seems to be you saying "Nowhere in Canada can get that warm at that time of year" without anything to back it up. Which I disagree with - even if this particular record is wrong that doesn't mean that 25 can never happen a single time anywhere in Canada in December.
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Old 09-18-2013, 12:59 AM
 
Location: Vernon, British Columbia
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I suppose I should give an explanation.

1) The surrounding weather stations all showed a temperature in the mid 50s that day.
2) The daily highs from the previous month have been stripped from the record book (I suspect because of a faulty thermometer). They should have also removed the first 4 days of December as well, but they were likely missed somehow.
3) The weather station was in operation for 66 years, and no other December temperature came even close to that date.
4) See the attached graph of the daily all time extremes at that location.

Weather Records That Should be Erased From the Record Books-grandforks.png
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Old 09-18-2013, 04:16 AM
 
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One record that should be erased is the temperature the WMO currently lists as "Highest temperature ever on Earth": 56,7 at Greenland Ranch, Death Valley on July 10th, 1913. That was a faulty thermometer which was too close to the ground and was also covered with sand at the time of the measurement.
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Old 09-18-2013, 02:44 PM
 
Location: Niagara Falls, ON
1,217 posts, read 1,114,334 times
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Quote:
Originally Posted by Glacierx View Post
I've noticed quite a few errors in the Environment Canada database, many of which are purported as fact when they are, in fact, clearly wrong.
Good find. I emailed EC and they told me that their data quality control team was investigating the issue.

Quote:
Grand Forks, BC, was 25C (77F) on December 4th, 1943, according to Environment Canada. This cannot be the case anywhere in Canada in December as I'm sure you would all agree to be so.
25c is possible somewhere in the country, maybe a 1 in 500 year event? I'm not sure what the national record is but St. Catharines has recorded at least 21.9c in December.

Last edited by Humid Subtropical; 09-18-2013 at 02:58 PM..
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Old 09-18-2013, 03:06 PM
 
Location: Vernon, British Columbia
3,018 posts, read 2,517,775 times
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Quote:
Originally Posted by Humid Subtropical View Post
Good find. I emailed EC and they told me that their data quality control team is investigating the issue.

I'm sure 25c is possible somewhere in the country, maybe a 1 in 500 year event? I don't know what the national record is for December but St. Catharines has recorded up to 21.9c.
25 is the national record, head and shoulders above anyone else. You also have to remember that southern interior valleys such as Grand Forks do not get very warm in the winter. You'll find much higher extremes in Alberta than you'll find around Grand Forks. The all time December maximum in Castlegar (near Grand Forks) is less than 12 degrees. Extreme 1 in 500 year heat waves do not just strike one town and leave everyone else around them untouched.

I notice that EC has fixed one of their mistakes. The changed a July 1st Quick, BC, temperature from -13 to +13. There are literally hundreds of other mistakes though. Here is another example: 50 degrees C in June.
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Old 09-18-2013, 03:42 PM
 
Location: Niagara Falls, ON
1,217 posts, read 1,114,334 times
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I don't disagree that the Grand Forks reading is a mistake. Do you know what the actual record is for the nation though? I'm sure 25c will happen eventually.

It looks like many of the stations having issues are missing a TC or WMO ID..
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Old 09-18-2013, 04:28 PM
 
Location: Vernon, British Columbia
3,018 posts, read 2,517,775 times
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Quote:
Originally Posted by Humid Subtropical View Post
I don't disagree that the Grand Forks reading is a mistake. Do you know what the actual record is for the nation though? I'm sure 25c will happen eventually.

It looks like many of the stations having issues are missing a TC or WMO ID..
I don't know, but possibly Lillooet, BC. I only have the data for BC on hand, so here are all occurrences of 20 degrees or more in BC since records began in 1873...

Location ===========Temperature==== Year ===Confidence Level
SCUDDER POINT-------------------------33.1-------1996-----0%<<EC has recently removed this value from their database.
DUNCAN GLENORA-------------------------28-------1996-----0%<<EC has recently removed this value from their database.
MALAHAT---------------------------------25.3-------1996-----0%
GRAND FORKS----------------------------25-------1943-----0%
SANDHEADS CS---------------------------23.4-------1999-----0%
GREY ISLET (AUT)------------------------23-------2004-----0%
ELKO-------------------------------------22.8-------1955-----1% <<EC has recently removed this value from their database.
108 MILE HOUSE ABEL LAKE----------------22.5-------2008-----0%
CRISS CREEK-----------------------------22.5-------2008-----0%
LILLOOET---------------------------------22.2-------1933-----95%
N VANC GRAND BLVD-----------------------22-------1996-----2%
CAPE SCOTT------------------------------21.1-------1899-----5%
HORSEFLY LAKE GRUHS LAKE----------------21-------2008-----0%
COWICHAN LAKE HATCHERY---------------20.6-------1943-----60%

Last edited by Glacierx; 09-18-2013 at 04:46 PM..
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Old 09-18-2013, 08:34 PM
 
Location: Saskatoon
753 posts, read 582,008 times
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I don't know if this one is wrong/inaccurate, but Canada's all-time humidex record was a whopping 53C set in Carman, Manitoba in 2007. According to the records the dew point hit 30C that afternoon, which just seems much too high for that area. Granted, the southeastern prairies do get periods of oppressive humidity during the summer, but a 30 degree dew point is literally Persian Gulf levels of humidity and would considered very high even in most tropical climates. So the fact that it happened in the middle of a continent with no major warm bodies of water nearby just seems a bit off.

I did ask about this in another thread, and someone said something about crops and how they can give high dew point readings due to evapotranspiration, or something of that nature. Does anyone have any knowledge/info on this sort of thing that they can share, and any idea whether this record is legitimate?

Quote:
Originally Posted by Glacierx View Post
I suppose I should give an explanation.

1) The surrounding weather stations all showed a temperature in the mid 50s that day.
2) The daily highs from the previous month have been stripped from the record book (I suspect because of a faulty thermometer). They should have also removed the first 4 days of December as well, but they were likely missed somehow.
3) The weather station was in operation for 66 years, and no other December temperature came even close to that date.
4) See the attached graph of the daily all time extremes at that location.

Attachment 118166
All right, fair enough then.
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Old 09-18-2013, 08:39 PM
 
Location: New Jersey
15,044 posts, read 13,102,898 times
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Quote:
Originally Posted by Morningrise View Post
I don't know if this one is wrong/inaccurate, but Canada's all-time humidex record was a whopping 53C set in Carman, Manitoba in 2007. According to the records the dew point hit 30C that afternoon, which just seems much too high for that area. Granted, the southeastern prairies do get periods of oppressive humidity during the summer, but a 30 degree dew point is literally Persian Gulf levels of humidity and would considered very high even in most tropical climates. So the fact that it happened in the middle of a continent with no major warm bodies of water nearby just seems a bit off.

I did ask about this in another thread, and someone said something about crops and how they can give high dew point readings due to evapotranspiration, or something of that nature. Does anyone have any knowledge/info on this sort of thing that they can share, and any idea whether this record is legitimate?
I don't know if they're accurate, but apparently similar dewpoints have been recorded in farmland located in the US Midwest (Iowa). I would guess it's also possible in Carman since it's in the same region, although it is farther north.
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