RENDLESHAM WEATHER STATION | FREE LEARNING CENTRE

Volume 7: Reading Weather Charts

Lesson 7.1: Synoptic charts

A synoptic chart shows pressure patterns, isobars and fronts at a stated time. Look at

the valid time and legend first. Low-pressure centres, fronts and tight isobar spacing

can help explain changing conditions.

Try it: Open a current Met Office surface pressure chart and describe the nearest

pressure centre.

Quick quiz: What is an isobar?

Answer: A line joining places with equal atmospheric pressure.

Lesson 7.2: Radar and satellite images

Rain radar estimates where precipitation is occurring, although it can miss light rain

or show false echoes. Satellites reveal cloud patterns, not a direct measurement of

rain at ground level. Animations are useful for observing movement, but do not

guarantee future conditions.

Try it: Compare radar imagery with what your rain gauge actually records.

Quick quiz: Does a satellite cloud image directly measure rain at your house?

Answer: No.

Lesson 7.3: Forecast models and uncertainty

Numerical weather prediction models calculate how the atmosphere may evolve.

Different models and ensemble members can disagree. Forecast confidence often

decreases further into the future, especially for exact shower locations. Use

probabilities and time ranges carefully.

Try it: Compare two forecasts for the same day and identify one uncertainty.

Quick quiz: Why can tomorrow’s shower timing change in a new forecast?

Answer: New observations and model calculations can alter the predicted outcome.

Talk about it: What did you learn, and how might it help you understand the weather where I live