12.4 Notes Weather Analysis

Main Idea: Weather maps are created to organize & describe meteorological (weather) observations.

ASPECTS OF WEATHER MAPS TEMPERATURE Lines on map: ISOTHERMS Describe: SMOOTH LINE CONNECTING AREAS OF EQUAL SURFACE TEMPERATURE. Pressure Lines on map: ISOBARS Describe: SMOOTH LINE CONNECTING AREAS OF EQUAL AIR PRESSURE.

RADAR MAPS Describe: Energy waves are sent out, & the amount reflected back is measured. Reflectivity Effects: The more energy reflected back, the higher the rainfall amount.

LIMITATIONS INCLUDE Ground clutter and Evaporation Ground Clutter: Buildings, elephants, swarms of bugs, or other energy waves can make storms look worse than they really ARE!

EVAPORATION When water evaporates before it reaches the ground, it can look like RAIN on a map!

MAIN IDEA 2: Weather predictions are not always accurate. However, much information & science goes into each forecast made.

5 Forecasting Methods: PERSISTENCE METHOD: DESCRIBE: “The weather tomorrow will be like the weather today.”

NUMERICAL MODELS: DESCRIBE: Scientists collect data & computers analyze it to predict weather.

CLIMATOLOGY METHOD: DESCRIBE: Weather on a particular day will be close to the average weather of that same date of past years. Uses: Long-term forecasts

ANALOG METHOD: DESCRIBE: Weather is predicted by comparing current conditions to past conditions that commonly produce bad types of weather. Uses: Predicting SEVERE weather!!

TRENDS METHOD: DESCRIBE: By looking at a storm’s starting point, direction, & speed & by understanding pressure & winds, the arrival of rain, snow, or hail storms are predicted. Uses: Predicting ARRIVAL of precipitation!