12.4 Notes Weather Analysis

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

• ASPECTS OF WEATHER MAPS

TEMPERATURELines on map: ISOTHERMSDescribe: SMOOTH LINECONNECTING AREAS OFEQUAL SURFACE TEMPERATURE.

PressureLines on map: ISOBARS

Describe: SMOOTH LINECONNECTING 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 INCLUDEGround clutter and Evaporation

Ground Clutter: Buildings, elephants, swarmsof bugs, or other energy waves can make storms look worse than they really ARE!

• EVAPORATION

When water evaporates before it reachesthe 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.

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

5 Forecasting Methods:

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

CLIMATOLOGY METHOD: DESCRIBE: Weather on a particular day willbe 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 startingpoint, direction, & speed & by understandingpressure & winds, the arrival of rain, snow, or hail storms are predicted.Uses: Predicting ARRIVAL of precipitation!