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

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!

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

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

Fun with Flashlights

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

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

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

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?

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.

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

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

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)

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

This is the only part we really care about!

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

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?

What a Difference 6 Months Makes! January July Why did the 1000-500mb thickness expand from 5419m to 5824m?

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

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

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

OK-FIRST Full Certification Course February 2006

A global composite water vapor image. ©Oklahoma Climatological Survey

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

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

Low (Cyclone) versus Wave

OK-FIRST Full Certification Course February 2006

OK-FIRST Full Certification Course February 2006

OK-FIRST Full Certification Course February 2006