We have covered how to read, interpret, and forecast variables such as temperature, wind, and moisture from weather maps. You'll apply this knowledge to the weather maps linked below.
It's Monday evening and you're in Vancouver. The model maps provided start on Monday morning and continue until Wednesday morning, every 3 hrs. As a reminder, you're evaluating your ski plans for the next day, Tuesday.
Clicking the button below will take you to a loop of a 70.0-kPa pressure-level map. In these maps the top row contains:
[Weather model name] | [Date/Time in Pacific Time] | [Date/Time in Universal Coordinated Time]
The latter time zone is used frequently in meteorology — think of it as a standard, universal time zone so that scientists around the world can reference times without having to convert. The bottom of the plot tells you what fields are plotted.
Tip: If you click in the slider bar at the top of the controls, you can step back and forth with the keyboard arrow buttons.
70.0 kPa weather forecast maps
If neither of these options work for you (to view the 70.0kPa weather maps) try the link below. This will bring up a PDF file showing all the weather forecast maps in sequential order.
Interpretation considerations
- Is there a front approaching your area of concern? If so, what kind of front is it?
- What are the expected low and high temperatures over your skiing elevation range?
- What does the moisture field tell you about the cloud cover? At what elevation?
- What are the winds going to do at the elevations you are concerned with?
Clicking the button below will take you to a loop of a 85.0-kPa pressure-level map.
If neither of these options work for you (to view the 85kPa weather maps) try the link below. This will bring up a PDF file showing all the weather forecast maps in sequential order.
Interpretation considerations
- Is there a front approaching your area of concern?
- What are the expected low and high temperatures over your skiing elevation range?
- What does the moisture field tell you about the cloud cover? And at what elevation?
- What are the winds going to do at the elevations you are concerned with?
You've learned about pressure and sea level pressure. Sea level pressure is plotted in contours on this map. The trickiest part of interpretation might be that not all of the contours are labelled.
Total cloud cover is in grey shading, with darker greys representing thicker, darker clouds. Note: the plot does not tell you what elevation the clouds are at.
Precipitation is shaded in colours. Now that we're covered the rain/snow line, you can use the above temperature plots to figure out freezing level, and the below plots to determine when and how much precipitation will fall. As a brief overview of precipitation amount, 0.25-1 mm in 3 hrs (lightest two shades of blue) is very light precip, 1-4 mm in 3 hrs (darkest two shades of blue) is light precipitation, 4-6 mm in 3 hrs (lightest shade of green) is moderate precipitation, 6-15 mm in 3 hrs (darkest 2 shades of green) is heavy precipitation, and above that is very heavy precipitation.
Lastly, this is liquid equivalent precipitation — this is how much liquid would result if you melted the snow that fell. To convert this to snowfall amounts, the simplest rule is to multiply by 10, e.g., 1 mm of liquid equivalent precipitation would be 1 cm of snow. Note: this rule does not always apply, but it's good enough for this exercise. If the precipitation falls as rain, no conversion is needed.
Sea Level Pressure / Clouds / Precipitation weather forecast maps
If neither of these options work for you (to view the Sea Level Pressure weather maps) try the link below. This will bring up a PDF file showing all the weather forecast maps in sequential order.
Interpretation tips
- What does the pressure pattern look like on your ski day? What does the pressure gradient look like?
- Do you expect precipitation? Rain? Snow? If snow, what would its characteristics be? How much will accumulate?