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Questions for Claire

Archives: February

I'm learning about clouds in school. Can you tell me what nimbus, cirrus, cumulus and stratus clouds look like and how high they are in the sky? Thanks!

Friday, February 6, 2009 | 10:30 AM PT

Question submitted by Connor Hayden
(Vancouver, BC)

Great question Connor!

Cloud types are widely varied, but in general the layers are split into three - low, middle and high. Low clouds are those found at 0-10000 feet, middle clouds are found from 10000-23000 feet and high clouds are above 23000 feet. Within each layer however there are many variations. There is a great web site that has pictures to show the typical cloud type at each layer: It's called "The Weather Doctor"

Within each layer there are 4 main types of clouds: Cirro form (high and wispy), Nimbo form (dark and stormy with the ability to have the cloud base lower to the surface during precipitation), Cumulo form (heaped, fluffy looking clouds) and Strato form (which are layered clouds). The National Weather Service has a great web site showing the different types of clouds and how they form.

I am very curious how you go about reaching your predictions. Could you share that info bit by bit with your viewers? I suspect many would be interested in understanding this a little more.

Friday, February 6, 2009 | 10:18 AM PT

Question submitted by John Boer
(Vancouver, BC)

John, I wish it was a simple process, but it's not!

Basically weather forecasting still boils down to pouring over numerical guidance charts, analysing current weather observations and understanding how the atmosphere will change with time under certain circumstances. Environment Canada does actually put some of their operational guidance charts on line - if you want to check them out, they can be found on the Environment Canada web site. There is even a small write up as to how the charts can be used.

I also use model output from other countries when it comes to looking at the longer term forecasts.

It takes me about 4 hours to do all the forecasting for the 18 cities that you see on the weather segment during The National. It takes me another 3-4 hours to forecast for BC and then make all the graphics that are required for the local show.

Claire, we are considering retiring to Vancouver Island. I know there are varied weather patterns on the Island but can't find a good source for average rainfall. hours of sunshine etc for the major cities / areas. Is there a source you can recommend?

Friday, February 6, 2009 | 10:08 AM PT

Question submitted by Don Lyster
(Calgary, Alberta)

First off Don, welcome to BC! You will love living here.

I get so many enquiries about historical weather records. So here's the answer, for everyone not just those sourcing out potential retirment locations (!). Environment Canada maintains a climate or historical weather on line site at: http://www.weatheroffice.gc.ca/canada_e.html

On the right hand side is a list of further links, click on the "Historical Weather" link and then when you are redirected - click on the "Climate Data Online" link.

I hope this helps.