1. cold front – cold air moves in under a warm air mass
cold front – cold air moves in under a warm air mass. Cold fronts often bring brief, heavy storms. There may be thunderstorms and strong winds. After the storm, the weather is usually cooler and drier.

2. cold front – cold air moves in under a warm air mass
cold front – cold air moves in under a warm air mass. Cold fronts often bring brief, heavy storms. There may be thunderstorms and strong winds. After the storm, the weather is usually cooler and drier.

3. warm front – warm air moves in over a cold air mass
warm front – warm air moves in over a cold air mass. Warm fronts often bring light, steady rain of snow. The precipitation may last for days. Winds are usually light. Warm front may also bring fog – stratus clouds that form near the ground. Afterward the weather is usually warmer and more humid.

4. warm front – warm air moves in over a cold air mass
warm front – warm air moves in over a cold air mass. Warm fronts often bring light, steady rain of snow. The precipitation may last for days. Winds are usually light. Warm front may also bring fog – stratus clouds that form near the ground. Afterward the weather is usually warmer and more humid.

5. warm front – warm air moves in over a cold air mass
warm front – warm air moves in over a cold air mass. Warm fronts often bring light, steady rain of snow. The precipitation may last for days. Winds are usually light. Warm front may also bring fog – stratus clouds that form near the ground. Afterward the weather is usually warmer and more humid.

6. warm fronts vs. cold fronts

7. thunderstorm – the most common type of storm

8. thunderstorm – the most common type of storm

9. tornado – a violent whirling wind that moves across the ground in a narrow path

10. tornado – a violent whirling wind that moves across the ground in a narrow path

11. hurricane – a very large swirling storm with very low pressure at the center

12. hurricane – a very large swirling storm with very low pressure at the center

13. hurricane – a very large swirling storm with very low pressure at the center

14. storm surge – a great rise of the sea along a shore

15. storm surge – a great rise of the sea along a shore

16. storm surge – a great rise of the sea along a shore