1. OK-FIRST Full Certification Course
Basic Meteorology
Earthstorm 2009
©Oklahoma Climatological Survey
February 2006

2. The Pre-Game Show Big picture vs. local detail: What do you need?
What really drives our weather?
The CEOs of weather
A few sidetracks
Air masses and fronts
Severe Wx Ingredients
Other Ingredients!

3. What are your weather data requirements?
OK-FIRST Full Certification Course
What are your weather data requirements?
(serious question)
February 2006

4. Our Methods are At Odds …
OK-FIRST Full Certification Course
Our Methods are At Odds …
Meteorologist in Oklahoma:
Big picture first, then drill down to local. You can’t make an accurate forecast without understanding the big picture. (We call this the forecast funnel)
Teachers in Oklahoma:
Local first! What is my immediate threat? I will worry about later, tomorrow, the next day, etc.!
Unfortunately, weather folks have been slow to provide information that is “friendly” to non-meteorologists.
February 2006

5. Fun with Flashlights

6. Equatorial (Tropical) Regions
Sun’s Incoming Rays
Polar Regions
Less Intense
Equatorial (Tropical) Regions
More Intense
Polar Regions
Less Intense

7. OK-FIRST Full Certification Course
This imbalance in the planet’s heating drives our “big-picture” weather
The atmosphere is constantly trying to “even things out” by sending warm air to the poles and cold air to the equator.
Exactly how does that happen?
OK-FIRST Full Certification Course
February 2006

8. Let’s get sidetracked …
Meteorologists are weird:
We love maps
We live in a different time zone
We play with balloons

10. We Love Maps! ALWAYS READ THE MAP LEGEND
Are these actual observations or are they forecasts?
When were the observations made?
When is the forecast valid?
What was the forecast lead time?
Who created the map?

11. Map Times
Most maps from commercial providers have clear, familiar times
Gov’t maps: another story
Z, GMT & UTC time: they’re all the same
Subtract five hours for CDT, six hours for CST
Ex.: 0354Z ( or “UTC”, or “GMT”) on the 11th is really 2254 CDT (10:54 pm CDT) on the 10th.

12. OK-FIRST Full Certification Course
What’s in a weather map?
State variables tell us a little bit about the state of the atmosphere:
Temperature
Moisture (relative humidity, dew point)
Wind speed and direction
Pressure / height
Almost all “station plot” type maps have each of these elements.
February 2006

13. A Surface Plot (OK Mesonet)
OK-FIRST Full Certification Course
A Surface Plot (OK Mesonet)
with ‘decoder ring’
February 2006

14. A Station Plot The wind barbs fly into the wind.
Long sticks = 10 mph
Short sticks = 5 mph
Pennant = 50 mph
NE of station: “wind gusting to” in mph
NW of station: Tair (air temperature)
SW of station: Tdew (dewpoint temperature)
SE of station: Rainfall (if any)

15. OK-FIRST Full Certification Course
“a mental picture of air motion”
February 2006

16. This is the only part we really care about!

17. The Troposphere (this is where the weather happens)
200 mb
About 40,000 ft.
300 mb
About 30,000 ft.
Meteorologists are big fans of 500mb
500 mb
About 18,000 ft.
700 mb
About 10,000 ft.
850 mb
About 5,000 ft.
1000 mb
About sea level

18. Radiosonde (wx balloon) locations
Each 3-letter station launches two balloons daily: 0Z and 12Z
So, what times of day does the Norman balloon fly?

19. What a Difference 6 Months Makes!
January
July
Why did the mb thickness expand from 5419m to 5824m?

20. The Troposphere (this is where the weather happens)
200 mb
About 40,000 ft.
300 mb
About 30,000 ft.
Meteorologists are big fans of 500mb
500 mb
About 18,000 ft.
700 mb
About 10,000 ft.
850 mb
About 5,000 ft.
1000 mb
About sea level

21. OK-FIRST Full Certification Course
TROUGH
TROUGH
RIDGE
A 500 mb map shows the state of the atmosphere “half way up”
February 2006

22. Looking Down at the North Pole
OK-FIRST Full Certification Course
Looking Down at the North Pole
Key Points:
The global connectivity
The alternating pattern: ridge-trough-ridge-trough
This ties in with the heat imbalance
Troughs are associated with cooling, Ridges with warming
February 2006

23. OK-FIRST Full Certification Course
February 2006

26. A global composite water vapor image.
©Oklahoma Climatological Survey

27. The CEOs of Weather
Ridges and Troughs play a prominent role in determining the big picture of the day’s weather.
They do not dictate the details at the surface!
Troughs are associated with disturbed weather:
Winder, cloudier, colder, possibly precip
Ridges are associated with more tranquil weather:
Calmer, sunnier, warmer, rarely precip

28. OK-FIRST Full Certification Course
TROUGH
TROUGH
RIDGE
A 500 mb map shows the state of the atmosphere “half way up”
February 2006

30. Low (Cyclone) versus Wave

31. OK-FIRST Full Certification Course
February 2006

32. OK-FIRST Full Certification Course
February 2006

33. OK-FIRST Full Certification Course
February 2006