Weather Appreciation

[Glacier]

Seriously ... Skagit River??? viewtopic.php?f=26&t=29869&p=1335955#p1335955

I'm rethinking some of these records including this one. I have done some research on temperature extremes lately, and have come to realize that they aren't as reliable as once thought. Recently (as in last September) the so called "hottest temperature on earth" recorded in Libya some 100 years ago was stripped from the record book after a "weather historian" in the states questioned the data (and rightly so).

The next hottest temperature ever recorded in California is also suspect, but even without that record, Death Valley is the hottest place on earth.

Upon further research, many, many of the other records are become suspect. Both the coldest and hottest temperatures ever recorded in Hawaii should be stripped from the record book. and therefore, Hawaii is the only State that has never recorded 100 degrees F.

The records in Canada pre-late 40s are pretty hit and miss. I notice that during the late 1800s York Factory, Manitoba was the frequently hitting 40 degrees despite being situated way up on Hudson Bay. This is highly suspect considering it was often the only place in Canada to do so some years.

The hottest temperature ever recorded in Newfoundland is supposedly 41.7 degrees occurring way up Labrador in August of 1914. This most certainly did not occur because 1) the temperature both the day before and the day after was only 18 degrees and 2) this would be as hot as any temperature ever recorded in BC during the month of August. Highly improbable for that part of the world.

I'm thinking of starting a blog that highlights some of the weather records that are suspect, but on another site where weather nerds abound in great number.

Let me just end this note on a positive comment. Not all records are suspect. The coldest temperature ever recorded in Canada during that cold February day in 1947 is most certain accurate. Since the thermometer only went down the -80 F, the meteorologist scratched the glass down to where the alcohol bottomed out. It looked to be -84 degrees, but they sent the thermometer to the lab in Ontario at which point they discovered that the thermometer was almost 3 degree off, and the true temperature was only -81.4 degrees F.

[GenesisGT]

With the mention of the temperature inversion over the valley right now, thought I would publish the upper wind/temperatures compared to the reported surface temperature, fyi. Currently the temperature is -7.1 and the upper temperatures forecasted over Penticton (closest place to Kelowna) are;

Kelowna Airport is at an altitude of 1421ft, the temperature at 6000ft is +03 and staying at +02 for the next day.

Edit: the temperature reported on Castenet is -7.1 the temperature reported at the airport is -2.

[Glacier]

On Monday, Whitehorse was +11 degrees. On Tuesday Fort Nelson was +11. Kelowna was about 15 degrees colder than that both days. The warm air has traveled far and wide, but kind of skipped over us!

The cold air has started to creep back into the northwest corner, so it's currently -11 up around Fort Nelson, but besides that Vernon is one of the coldest spots in BC right now at -5. Only Princeton (-10), Merritt (-7), Clinton (-6), and Yoho National Park (also -6) are colder.

[LoneWolf_53]

Kelowna Airport is at an altitude of 1421ft, the temperature at 6000ft is +03 and staying at +02 for the next day.

When I was flying back from Ontario a few days back, it was -82C at 38,000ft.

[Glacier]

Two winters stand out as the most brutal in the entire history of this province (records began in 1873). They were the winter of 1949/1950 and the winter of 1968/1969. Which one was worse depends on how and where you measure it.

January of 1950 was the coldest average month. Kelowna was below -20 for 21 of 31 days, and the temperature dropped below -30 even in Oliver where it was -31. Higher up, Chute Lake was -42 and Joe Rich was -43. Westwold was -50 degrees Fahrenheit (-45.6 C). Prince George was -50 Celsius (-58 F).

The winter of 1968/69 started earlier and lasted longer, but January was not quite as cold. The average in Kelowna was only -12.3 instead of the -15.7 experienced in 1950.

The Kelowna airport, which did not exist in 1950, shattered the city's all time record in December of 1968 by recording -36.1 degrees, and at the same time Vernon was -38.9. Note that the airport is in a low spot sheltered from the wind, and thus allows the cold air to sink down into the valley bottom. This is often referred to as a frost hollow. The Puntzi Mountain airport, another frost hollow that never existed in 1950 - and situated a mere 2 degrees lattitude north of Kelowna, set the all time provincial record for the coldest December temperature ever recorded in BC at -63 degrees F (-52.8 C). This value tied record set up by the Yukon border at Smith River during the 1949/50 winter.

Comparing the average temperatures between the two winters, most places in southern BC were slightly colder in 1949/1950 (although Kelowna was not), but the more recent winter was colder in the far northern part of the province.

Two other winters could be considered runner-up winters. The winter of 1971/72 never got super cold, but the average was almost as cold as 1968/69. In addition to the cold, this winter had oodles of snow. Normally dry places like Kamloops had almost a meter of snow on the ground. 1917 was also bitterly cold, but most of us weren't around then.

Keeping in mind that Penticton, Kelowna, and Vernon averaged -5.9, -6.3, and -9.2 in 1949/1950, here are the coldest winters on record in BC:

1) -30.5 in 1968/69 at Lower Post
2) -29.3 in 1968/69 at Smith River
3) -28.0 in 1949/50 at Smith River
4) -28.0 in 1971/72 at Lower Post
5) -26.0 in 1968/69 at Fort Nelson
6) -25.2 in 1955/56 at Smith River
7) -24.8 in 1971/72 at Fort Nelson
8) -24.7 in 1949/50 at Fort Nelson
9) -24.2 in 1968/69 at Dease Lake
10) -24.2 in 1981/82 at Fort Nelson

[Cumungala]

Imagine it being an average temperature of -30 for a whole month like it was in Lower Post. Wow. 1949-50 must have been a year where Okanagan Lake froze over, and probably 1968-9 was also.

This has been a pretty good winter so far. There has been snow on the ground at my house and in all parts of Kelowna (even right down to the lake) continously since about December 10th. Thats almost 45 days and counting. There was a short period around Christmas and New Years where there were quite a few bare patches on my lawn, but areas only a block away still had a full snow cover.

This is what I think the number of days of snow on the ground would be for a normal winter in towns around the Okanagan. Some of these numbers are precise and from the climate normals on the Environment Canada website.

Grand Forks: 85 days
Midway: 85 days
Greenwood: 100 days
Keremeos: 70 days
Princeton: 100 days
Osoyoos: 50 days
Oliver: 50 days
Okanagan Falls: 60 days
Penticton Airport: 35 days (actual, but it seems a bit low to me)
Naramata: 45 days
Summerland: 70 days
Peachland: 45 days
West Kelowna away from lake: 70 days
West Kelowna by the lake: 50 days
Kelowna by the lake: 50 days (closer to downtown core) 60 days (all other areas, even down to the lake)
Glenmore/ East Kelowna/ Rutland: 70 days
Kelowna Airport: 75 days (actual)
Joe Rich: 110 days
Beaverdell: 110 days
Big White: Probably 250 days lol
Winfield: 80 days
Vernon by the lake: 65 days
Vernon away from the lake: 80 days (actual)
Lumby: 85 days
Cherryville: 100 days
Armstrong: 80 days
Enderby: 85 days
Salmon Arm: 70 days

Vancouver: 10 days maybe

[Glacier]

Imagine it being an average temperature of -30 for a whole month like it was in Lower Post. Wow. 1949-50 must have been a year where Okanagan Lake froze over, and probably 1968-9 was also.

49/50 was indeed a cold one. The average January temperature in Penticton is -1.7, but in 1950 it was -14.3 (a full 12.6 degrees below normal). The central interior were even more below normal. Prince George and Vavenby were more than 19 degrees below normal. Fort Nelson was only 6.2 degrees below normal. The 19.2 degrees below normal in Vavenby is the most below normal ever recorded in BC (Atlin was also 19.2 degrees below normal in December of 1917).

Apparently, Okanagan Lake has only frozen over fully on two occasions, with 1949/50 being the most severe of the two. The other year was 1906/07, but a few of the other cold winters were close.

An interesting note: While January of 1950 was the coldest month in BC, February of 1936 was the coldest month in Canadian history with 3.6% of the country being at least 10 degrees below normal.

The following picture shows Okanagan Lake in 1936

[Glacier]

The following graph shows the average wettest day of the year in BC and Alberta. Notice that our part of the world is the only area area of the map (and indeed Canada outside of the high arctic) whose wettest day of the year is typically less than 20 mm.

[Glacier]

Even the coldest month on record was able to be warmer than the warmest January on record for a day, but 2013 could not...

[Spocky]

I apologize if this point has been brought up before (I didn't read all 22 pages... sorry) but I'm rather incensed at how Kelowna's climate is misrepresented by the EnvCan location at the Airport. A couple of days ago I went up to Vernon and was amazed at how there was about 30% snow cover in Kelowna city proper, around a foot of snow in the fields around the airport, but by the time I got up to Crystal Waters just a few minutes up 97 the cover was actually less than Kelowna city! That cold snow hollow the airport is in is the completely wrong place to have the weather station as it is not indicative of the conditions closer to the lake where most of the population lives. It's a similar dichotomy to Victoria where Gonzales gets about half the precip of the Airport! If only Vic Airport was listed, Victoria couldn't claim its dry and sunny reputation (which really only extends to the southern half of Oak Bay anyway...) There should be a downtown weather station reporting to EnvCan and the current one should be renamed Kelowna Airport to show the difference. But then again, I'm having problems with EnvCan lately anyway. In at least three separate occasions in the past couple of weeks they have forecast a low temp for that night as late as midnight and that temp has been exceeded in the minus category by up to 7 degrees! That's a heckuva spread in a very short term forecast! Another ridiculous example of EnvCan folly is that Summerland and Osoyoos share exactly the same forecast every day even though the difference can be 3 or 4 degrees (Osoyoos can be colder in winter and warmer in summer). Anyway, [RANT OFF].

[Glacier]

You are absolutely right about the airport not being representative of the majority of the city. The airport sits in a frost hollow, meaning that overnight temperatures are much colder than elsewhere in the city. This is due to the geographic low spot as well as the lack of wind (no wind + no sun = temperature inversion).

There is a significant difference between the Victoria airport and Victoria in terms of precipitation and sunshine, but not so for Kelowna. The Kelowna airport is not any less sunny than the rest of the city. Oliver and Penticton receive less sunshine than the airport while Summerland and Vernon receive more - mostly because Vernon and Summerland are in open areas with smaller surrounding hills.


Check out my sunshine map for the province.

[GenesisGT]

I apologize if this point has been brought up before (I didn't read all 22 pages... sorry) but I'm rather incensed at how Kelowna's climate is misrepresented by the EnvCan location at the Airport

A quick note of clarification, EnvCanada does not operate/own the weather reporting station at the Kelowna Airport, it is owned and operated by NAV CANADA, the company that provides air navigation services across Canada. The first use for the reporting of weather at the airport is for aviation purposes. Having said that a reporting station has to meet certification criteria outlined by the World Met Org (WMO) and EnvCan, to have a certified weather station by the water in the city area some one would have to provide a piece of land that meets the criteria. Such as size of lot with no buildings, trees, etc within a certain distance.

[Woodenhead]

This is why you need to take all stats & records with a small grain of salt - weather stations aren't always in the best places, or enough places - local variations can & do occur.

[Glacier]

I know what you mean, although the differences are fairly consistent from year to year (if stations are set up properly). The airport is about 1 degree colder than downtown, but it's a couple of degrees warmer than Joe Rich Creek. Last month the entire Okanagan valley was right on normal +/- a half degree. The airport was just under a degree colder than Winfield, but they were both 0.2 to 0.3 degrees above their respective normals. The extreme cold at the airport was -18 while the extreme cold in Winfield was only -12.5, as we would expect.

Local variations occur, and that is why it's important to keep long term records at the exact same spot, and at a location that doesn't see the city encroaching around. The Osoyoos weather station is in a horrible spot because of its proximity to pavement, and there was talk about moving it up to the airport. The idea was shot down, and I suspect by the town because it would mean a cooler average, which would not fit into their tourism marketing plan.

Most or at least a lot of the CS weather stations seem to exaggerate the actual temperature, I suspect due to faulty equipment. It seems that most of them including the Osoyoos station show more accurate readings now. The two Osoyoos stations were only a couple hundred meters apart, and thus the large temperature difference we see in the 1990s is likely due to poor site selection (eg. pavement too close) or faulty equipment. It looks like the problem was largely fixed in 2005.

P.S. another sign that the weather station exaggarated the temperature is that between 1992 and 2002 Osoyoos recorded year extreme maximum temperature for the province 8 different years. This is quite unusual from the norm because at no time in previous history nor since 2002 has it been the hot spot.

When we look at the extreme values obtained every year, the differences are even more severe. A couple 100 meters apart at the same elevation should never result a 2 degree difference let a long a 3 and 4 degrees difference if the weather stations are set up properly.

This is for the month of July

The Oliver STP weather station is also a bad representation because of the gravel.



Hence the reason, it tends to read so higher than other Oliver station.

This is for the month of July

[GenesisGT]

Below is a picture of the Revelstoke weather observing compound, which gives an idea of the size and how it is situated. The picture is from an article in The Revelstoke Current (April 2011) which indicates the compound is being moved closer to the airport/runway so IFR approaches could be developed for the airport and the airport could be certified for scheduled flights. If the weather compound is not within a certain distance to the runway then the reports are not considered accurate enough for some aviation uses, such as runway approach minimums.

I wonder if having moved the compound will have any affect on the long term climate data?

http://www.revelstokecurrent.com/2011/04/27/new-automated-weather-station-cuts-trail-through-the-flats/