1. NATS 101 Lecture 3 Climate and Weather

2. What is Pressure at 0.8 km? (Tucson, Arizoina)
Use Equation for Pressure Change

3. What is Pressure at 1.6 km? (Denver, Colorado)
Use Equation for Pressure Change

4. What is Pressure at 8.7 km? (Mt. Everest)
Use Equation for Pressure Change

5. “Climate is what you expect. Weather is what you get.”
Climate and Weather
“Climate is what you expect.
Weather is what you get.”
-Robert A. Heinlein

6. Weather Weather – The state of the atmosphere: for a specific place
at a particular time
Weather Elements
1) Temperature
2) Pressure
3) Humidity
4) Wind
5) Visibility
6) Clouds
7) Significant Weather

7. Responsible for boxed parameters
Surface Station Model
Responsible for boxed parameters
Temperatures
Plotted F in U.S.
Sea Level Pressure
Leading 10 or 9 is not plotted
Examples:
plotted as 138
998.7 plotted as 987
plotted as 360
Ahrens, p 431

8. Sky Cover and Weather Symbols
Ahrens, p 431
Ahrens, p 431

9. Wind Barbs Direction Wind is going towards Westerly  from the West
Speed (accumulated)
Each flag is 50 knots
Each full barb is 10 knots
Each half barb is 5 knots
65 kts from west
Ahrens, p 432

10. SLP pressure
temperature dew point
cloud cover
Ohio State website
wind

11. Practice Surface Station
Temperate (oF)
Pressure (mb) Last Three Digits (tens, ones, tenths)
Dew Point (later) Moisture
Wind Barb Direction and Speed
Cloud Cover Tenths total coverage
Ahrens, p 431 72 58
111
Decimal point
What are Temp, Dew Point, SLP, Cloud Cover, Wind Speed and Direction?

12. Practice Surface Station
Sea Level Pressure
Leading 10 or 9 is not plotted
Examples:
plotted as 138
998.7 plotted as 987
plotted as 360
Ahrens, p 431 42 18
998
Decimal point
What are Temp, Dew Point, SLP, Cloud Cover, Wind Speed and Direction?

13. Surface Map Symbols Fronts
Mark the boundary between different air masses…later
Significant weather occurs near fronts
Current US Map
Ahrens, p 432

14. Responsible for boxed parameters
Upper-Air Model
Responsible for boxed parameters
Conditions at specific pressure level
Wind
Temperature (C)
Moisture (Later)
Height above MSL
UA 500mb Analysis
Ahrens, p 431
Ahrens, p 427

15. Climate
Climate - Average weather and range of weather, computed over many years.
Whole year (mean annual precipitation for Tucson, 1970-present)
Season (Winter: Dec-Jan-Feb)
Month (January rainfall in Tucson)
Date (Average, record high and low temperatures for Jan 1 in Tucson)

18. Climate of Tucson Monthly Averages
Individual months can show significant deviations from long-term, monthly means.

19. Average and Record MAX and MIN Temperatures for Date

20. Climate of Tucson Probability of Rain
Cool Site: Western Region Climate Center

21. Climate of Tucson Extreme Rainfall
Cool Site: Western Region Climate Center

22. Cool Site: Western Region Climate Center
Climate of Tucson Snow!
Cool Site: Western Region Climate Center

23. Summary Weather - atmospheric conditions at specific time and place
Weather Maps  Instantaneous Values
Climate - average weather and the range of extremes compiled over many years
Statistical Quantities  Expected Values

24. Reading Assignment Ahrens Pages 25-30 Problems 2.1-2.4
(2.1  Chapter 2, Problem 1)
Don’t Forgot the 4”x 6” Index Cards… I’m getting antsy for a pop quiz You must be lusting for one too!