Explore the characteristics of and be able to identify on a weather map: High and Low pressure systems; Warm, Cold and Occluded fronts; and Weather associated with each feature. Classroom participants would also take part in a guided forecast exercise.

1. Kyle Nelson, Meteorologist
@wxkylenelson

2. Weather awareness:
Leave it to others?
https://twitter.com/WNST/status/402141803475779584

3. “Dude, powder day tomorrow?”
Or more commonly:
“What is the weather going to be like today/tomorrow?”
Million Dollar question:

4. Get the forecast right…
Great day!
Feeling of
accomplishment
Point against anyone
who doubts your skills

5. Get it wrong…
Plan “B”?
You’re probably
buying beer
tonight
Don’t be this guy!! 

6. In the next ~28 minutes…
We will explore the characteristics of and be
able to identify on a weather map:
High and Low pressure systems
Warm, Cold and Occluded fronts
Weather associated with each feature
Participate in a guided forecast exercise

7. What do you know about
weather? (pre-test)
10 questions
3 minutes

8. What Drives Our Weather?
The Sun – The
principal source of
light and heat energy
4-8-S290-EP

9. What causes weather?
When air masses with different properties collide
Variables: Temperature, Moisture, Wind Velocity
Atmosphere wants to be well-mixed

11. Air Mass
Body of air with similar temperature and
moisture characteristics

12. Temperature
Measure of how hot or cold something is
Device: Thermometer
Warm air rises, cooler air falls
Warmer air is less dense
Can hold more moisture

13. Air Mass Origins
Maritime
Moist
Continental
Dry
Polar
Cold
Tropical
Warm

14. Pressure
Force per unit area
Directly related to mass
Device: Barometer
Warmer air has lower pressure than cooler air

15. Winds
Winds are driven by
temperature differences
which create pressure
differences
Responsible for
transporting weather
systems and air masses
Device: Anamometer

16. A boundary between two different air masses
Fronts

17. -Warm air overtakes a cooler air
-Slow moving
-Less dense air overriding denser air
Warm Front

18. • Precipitation along and ahead of the front
• Wind shift from east to south as front passes
Warm Front

19. -Cooler air mass slides under a warm air mass
-Fast moving
-Dense air settling under less dense air
Cold Front

20. • Precipitation along the front
• Wind shift from south to west as front passes
Cold Front

21. • Cold front catches up with a warm front
• Moves with the low pressure system
Occluded Front

23. Low Pressure
• Rising air
• Unsettled weather
• Associated with fronts
• Circulation
• Right hand rule

24. Low Pressure
• Different precipitation types
depending on location
• Snowfall and precipitation
type forecasting is difficult!

25. High Pressure
• Sinking air
• Fair weather
• Circulation
• Right hand rule

26. Great method for weather in the field!
Stand with your back to the wind. Low pressure will be to your left.
(In the northern hemisphere)
Buys-Ballot’s Law

27. Seasonal Differences
Summer Winter

29. Surface weather maps
But these are just dots and lines and numbers!!
How a numerical model sees weather
Data points on a grid
Where are the highs, lows and fronts?
Did someone say colored pencils?

30. Fronts: Look for wind shifts and temperature changes
Pressure centers: Look for winds spiraling
into (Low) or out from (High) a point
Plot fronts and pressure centers

31. Fronts: Look for wind shifts and temperature changes
Pressure centers: Look for winds spiraling
into (Low) or out from (High) a point
Plot fronts and pressure centers

34. We harness technology!
Computer models make first guess
Forecasters add value, especially for snowfall

35. Case study review: Time 1

36. Case study review: Time 2

37. Case study review: Time 3

38. Case study review: Time 4

39. Case study review: Time 5

40. Where would you expect
snow to fall?

41. Before

42. After

43. Snow Totals Dec 19-20, 2012

44. What did you learn about
weather? (post-test)
10 questions*
2 minutes
*These may look very familiar…

46. Image Sources
http://ww2010.atmos.uiuc.edu/(Gh)/home.rxml
http://www.weather.gov/mkx/122012-winterstorm
http://www.weather.gov/lot/2012dec20
https://en.wikipedia.org/wiki/Buys_Ballot%27s_law
http://www.theweatherprediction.com/habyhints2/440/
http://www.ncep.noaa.gov/
http://visibleearth.nasa.gov/
http://www.pinterest.com
http://www.aos.wisc.edu