What is the cause of strong winds?

What is the cause of strong winds?

What is the cause of strong winds? Photo: wwwuppertal The wind is simply air in motion, flowing from high atmospheric pressures to low pressures. Moving anything requires a force. Strong winds are due to a strong pressure gradient force. A… More »

Sun pillar

Sun pillar

Sun pillar Sun pillar at sunrise by CaptPiper The other morning, I saw a column of light above the rising sun — what was that? A rising, or setting, sun behind high clouds will sometimes project a vertical shaft of… More »

What is sleet?

What is sleet?

Sleet is translucent balls of ice that are frozen raindrops. The most common forms of precipitation are rain, snow, freezing rain, and sleet. In Wisconsin, precipitation usually begins as ice particles in a cloud. The temperature conditions below the cloud base determine if the precipitation ends up as rain, snow, freezing rain, and sleet. More »

What is the coldest wind-chill temperature ever recorded in Madison?

What is the coldest wind-chill temperature ever recorded in Madison?

What is the coldest wind-chill temperature ever recorded in Madison? Photo: LongitudeLatitude The face of a frigid windchill. The wind-chill temperature describes the increased loss of heat by the movement of the air. The wind-chill is relevant to humans and… More »

Where does the water come from in Midwestern snow storms?

Where does the water come from in Midwestern snow storms?

Where does the water come from in Midwestern snow storms? ENLARGE Photo: NOAA/NASA GOES Project Water can travel a long way to dump onto the Midwest as snow. This picture shows the storm system that cause the massive February 2011… More »

Do abundant snowstorms suggest global warming is not occurring?

Do abundant snowstorms suggest global warming is not occurring?

Do abundant snowstorms suggest global warming is not occurring? ENLARGE Graphic: Rutgers University Global Snow Lab This graphs shows the area of land covered by snow over the past few decades in North America. No. These storms are individual weather… More »

Why do bridges ice before the road?

Why do bridges ice before the road?

Why do bridges ice before the road? People in cold climates are used to signs warning that “bridge freezes before road.” Water on surface will freeze once the surface becomes cold enough, but why does the road cool faster? ENLARGE… More »

What is freezing rain?

What is freezing rain?

What is freezing rain? ENLARGE Photo: Mike Giovinazzo Freezing rain covers everything with a sheet of ice. When water particles fall from clouds and reach the surface as precipitation, they do so primarily as rain, snow, freezing rain or sleet.… More »

Why does snow disappear?

Why does snow disappear?

Why does snow disappear? ENLARGE Photo: Amanda Graham Sublimation in action. When the snow builds up on my patio, it starts to evaporate after a few days, even though the temperature is still below freezing. On average, what percentage of… More »

What are the northern lights?

What are the northern lights?

What are the northern lights? Aurora Borealis over Iceland, by Moyan Brenn The northern lights, also called aurora borealis, are an evening light show seen as a diffuse glow or as overlapping curtains of greenish-white and sometimes red light. Auroras… More »

How do ice ridges form on a lake?

How do ice ridges form on a lake?

How do ice ridges form on a lake? ENLARGE Photo: Jeff Miller Pressure ridge near shore on Lake Mendota in Madison, WI Lake ice formation is dynamic. Even when a lake is completely frozen, the ice is not stagnant. It… More »

Why do I feel colder on a damp day?

Why do I feel colder on a damp day?

Why do I feel colder on a damp day? © S.V. Medaris A damp, January morning brings hoarfrost to a Wisconsin farm. Let’s define a damp day as one with high relative humidity but without precipitation or fog. High relative… More »