Weather Basics: Wind

Summary

This video provides an in-depth exploration of wind, including its causes, types, and effects. It explains how wind develops due to temperature differences between air masses, and the role of jet streams in weather patterns. The video also covers various wind types, such as land and sea breezes, upslope and downslope winds, Chinook winds, and Santa Ana winds, highlighting their characteristics and impacts. Additionally, it touches on the relationship between wind and weather phenomena like temperature inversions and wildfires.

Takeaways

• 🌬️ Wind is caused by differences in temperature between air masses, leading to variations in air density and pressure.
• 🌀 Jet streams are fast-flowing, narrow air currents found about seven miles above Earth's surface, typically exceeding 100 mph.
• 🌍 In North America, two significant jet streams influence weather: the subtropical jet and the polar jet, with the latter having a more direct impact.
• 🔄 Jet streams can act as steering mechanisms for storm systems, influencing their movement and development.
• 🏞️ Land and sea breezes are local wind patterns resulting from the temperature differences between land and water bodies.
• ⛰️ Upslope and downslope winds occur in mountainous regions, with upslope winds during the day as air warms and rises, and downslope winds at night as air cools and descends.
• 🌡️ Temperature inversions can occur when cool air settles in valleys, with warmer air above it, potentially leading to fog formation.
• 🌤️ Chinook winds are warm, dry winds that can rapidly increase temperatures and melt snow in the Pacific Northwest.
• 🔥 Santa Ana winds are dry, warm winds in Southern California that can escalate wildfire risks by drying out vegetation.
• 📊 The highest recorded surface wind speed was 231 mph at Mount Washington, while the highest measured wind speed was within an F5 tornado at 318 mph.

Q & A

What causes wind?

Wind develops in response to differences in temperature between air masses, which can also be expressed in terms of density or pressure. Air flows from a denser air mass or one of higher pressure toward a less dense, low-pressure air mass.

What are isobars and how do they relate to wind strength?

Isobars are lines of constant pressure on a weather map. The tighter the isobars, the stronger the winds.

What is a jet stream and where are they typically found?

Jet streams are fast-flowing, relatively narrow currents of air found about seven miles above the Earth's surface. They form at the boundaries of adjacent air masses with significant temperature differences and typically exceed 100 miles per hour in speed.

How do jet streams influence weather patterns?

Jet streams can serve as steering mechanisms for storm systems, influencing the path and behavior of weather patterns. They can also affect the flow of colder air southward during seasonal transitions.

What are the two branches of the jet stream that affect North America?

The two branches of the jet stream that affect North America are the subtropical jet and the polar jet.

How do land and sea breezes form?

Land and sea breezes form due to temperature differences between land and water. In the morning, the land is cooler than the water, creating a land breeze as air moves from the land to the water. In the afternoon, the land heats up more than the water, leading to a sea breeze as air moves from the water to the land.

What is an upslope wind and when does it typically occur?

An upslope wind occurs when air warms along the sides of hilly or mountainous terrain and rises up the slopes. This typically happens during the day as the Sun warms the slopes.

What are chinook winds and what effect do they have on temperature?

Chinook winds are warming winds from the ocean into the interior regions of the Pacific Northwest. As the air moves down the eastern slopes of mountains, it accelerates, dries, and warms, leading to significant temperature increases, sometimes by 20 to 40 degrees or more.

What are Santa Ana winds and when are they most prevalent?

Santa Ana winds are dry, warm winds that blow into Southern California from the surrounding desert. They are most prevalent in the fall and winter, with a peak in September through March.

Why are Santa Ana winds dangerous?

Santa Ana winds are dangerous because they quickly dry out vegetation, increasing the risk of wildfires. If a fire starts, the fast-moving, dry, and hot winds can spread the fire rapidly.

What is the highest recorded surface wind speed and where was it recorded?

The highest recorded surface wind speed is 231 miles per hour, which was recorded at the Mount Washington observatory in New Hampshire in April of 1934.