nav canada weather

by Greg
(Canada)

Nav Canada Organization

Nav Canada Organization

How do I read an upper wind report from Nav Canada weather web site?


Barry's Response - Greg: Yeah, that's a good question. From what I understand, these are machine-generated tables that meteorologists don't need to use every day. I never finished the operational training, though.

Tables are sorted by station and assigned latitude and longitude ids. The next two lines in the left column indicate the forecast comes from the Canadian Meteorological Center in Montreal.

After that, it gives the date and Zulu time of the last input. "For use" indicates the Zulu hours for which the wind forecast is intended. There's a row at the top with elevations (when in doubt, assume ASL).

Here's the shakey part. It looks to me like a direction (2-digit) then speed (presumably knots like all other speeds on the site), since the group of four digits always starts with a pair ranging from 01 to 36. After that, there's a minus (and occasional plus) sign followed by another pair of digits, but not in the lowest column.

Could this value be a sign of shear? Maybe a standard deviation or gusting values. I wouldn't expect anything but shear at higher latitudes, but it's best to ask an air traffic controller, flight service specialist or experienced pilot.

Bottom line:

Ya got me! But I did a little more research.

You may find it challenging to read an upper wind report from the Nav Canada weather website at first, but with a little practice, you will become familiar with the format and key information.


Here's how to navigate the report:

- The upper wind report is under the aviation or pilot-specific section on the Nav Canada weather website. Look for a section called "Upper Winds" or "Upper Air."

- Identify the altitude: The upper wind report will give you specific altitudes, usually in flight levels or pressure levels (e.g., FL250 or 300mb). Find the altitude that's right for you.

- Wind direction and speed: The upper wind report will tell you the wind direction and speed at your altitude. Wind direction is given in degrees, showing where the wind is coming from. Knots are usually used to measure wind speed.

- The upper wind report may include temperature, dew point, and other atmospheric parameters in addition to wind information. They're useful for flight planning and assessing weather.

- Upper wind reports may include symbols and abbreviations that represent different meteorological elements. To understand these symbols and abbreviations, refer to the website's legend or key.

- Think about the validity period: Upper wind reports are usually valid for a certain period. Check the validity period of the report to make sure it's up-to-date.

- Don't be afraid to ask for help: If you're unsure about anything about reading the upper wind report, don't be afraid to ask experienced pilots, meteorologists, or aviation professionals. You can get valuable insights from them and understand the information better.


Search this site for more information now.

It takes practice and knowledge of aviation weather terminology to read upper wind reports. As you get more comfortable with these reports, you'll get better at interpreting them.

Want to go a little deeper?

Hodographs and Ekman spirals are both meteorological concepts related to wind patterns.


What they are and how a novice can find and use them:

- Hodographs are graphical representations of wind speed and direction at various altitudes. This shows how the wind changes with height. Hodographs are used in meteorology and aviation to analyze wind shear and storms.

You can find a hodograph on meteorological websites, research papers, or textbooks about atmospheric dynamics. The output of some weather models and forecasting tools may also include hodographs.

You need to know how to interpret a hodograph's shape and characteristics. Hodographs can tell you about wind speed, wind direction, wind shear, and severe weather potential. The best way to learn to read hodographs is to ask a meteorologist or study resources specifically about it. Check this Wikipedia article for an example: https://en.wikipedia.org/wiki/Hodograph

- The Ekman spiral describes the pattern of wind direction and speed in the ocean or lower atmosphere as depth increases. The Coriolis effect and frictional forces act on moving air or water to cause it.

You can learn about fluid dynamics and the Coriolis effect (where the wind pretends to curve to the right) from educational resources, textbooks, or online tutorials. Ekman spiral diagrams and visualizations can also be found on some meteorological and oceanographic websites.

Using the Ekman spiral concept, beginners can learn how wind patterns change with depth in the ocean or lower atmosphere. It helps explain how water and air masses mix vertically and the direction of surface currents. Oceanography, marine navigation, and atmospheric science can all benefit from understanding the Ekman spiral.

Wikipedia again to the rescue: https://en.wikipedia.org/wiki/Ekman_spiral

You can ignore the partial derivatives in the article and just look at the text and drawings if that suits you.
Both hodographs and the Ekman spiral are more advanced topics in meteorology and oceanography. To deepen your understanding and use of these concepts, consult reputable educational sources, talk to experts in the field, or take courses or tutorials.

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THANKS
by: Barry

All, thanks for you input. I intend to revisit this in the future. The article referred to is at https://www.stuffintheair.com/weatherstations.html

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just started its training
by: barty

I am undergoing its training right now. I have just started and I really do not know how to help you right now. So I will get back to you after some time. Just remember me.

From Barry - Wishing you all the best as you go through Nav Canada's air and weather services training! You'll gain the knowledge and skills you need to excel in your training with dedication and perseverance.

Make sure you take your time to learn and absorb the information, and don't be afraid to ask for help when you need it. When you're ready, your leaders will be here. Wishing you the best of luck on your journey.

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Upper wind decode
by: Anonymous

3000 ASL foot winds do not contain temperature forecast, all temperatures above 30000 ASL are negative

Coded format:
site ddss ddssttt ddssttt etc...

where site is the where the forecast is for

where dd is direction the wind is from in degrees true divided by 10 where 01 actually means 010, 35 means 350 (think runways: runway 24 is aligned along 240)

where ss is speed in knots

where ttt is temperature in celcius, the first character is + or -

exceptions: if wind speed is greater than 99 knots add 50 to dd and subtract 100 from sss (e.g. 9000 foot winds over Ottawa are forecast to be 290 at 119 knots temperature -22 is coded as 7919-22)

does that help?

From Barry - There will be a lot of trainees who are just starting out who will benefit from this.

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has good knowledge
by: Anonymous

was very informative and interesting

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...
by: Anonymous

those are things that meteorologists understand better. it's all science and mathematics. I'm sure that after a few weeks on learning, everyone can understand it. Nice article. 5 stars

From Barry - Thank you.

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nav candada weather comment
by: Anonymous

At first this seemed like a promising post. There was some relatively technical information which seemed to make sense, and then you dropped the ball! You ALMOST got this thing figured out! Do a little more searching and see if you can come up with a difinitive response for this guy. Also, this is a case where a picture or diagram would be really valuable. See if you can find one of those to put on here as well.

From Barry - I enjoy ensuring that my answer is accurate and up-to-date by researching the question thoroughly and finding reliable sources. Taking a look at the different perspectives on the issue also helps us understand it better.

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Nav Canada Weather
by: doglover

thought it was interesting as a first impression. it would be cool to find how the air quality and meteorology works with the plus and minus. the zulu and knots. it would be cool to learn alot more about all of it plus you can never gain too much knowledge.

From Barry - I'm looking forward to learning new things from this and how it can help me in the future. I hope it'll be a great learning experience for all my readers too.

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