Where The Fronts Are

• A front is the leading edge of an air mass.

• If it is the front of a cooler air mass, it will be a COLD FRONT.

• If it is the front of a warmer air mass, it will be a WARM FRONT.

How to tell where a front belongs on a map.

• A front will be located where the temperature changes rapidly in a short distance.

• Isotherms will be close together.

Warmer airCooler Air

50°F

30°F

35°F

40°F

40°F

45°F

45°F

50°F

30°F

35°F

25°F

Now that we know WHERE the fronts are, how do we know what

KIND they are?

• It depends on which direction the line you just drew is moving…

Thisline

Now that we know WHERE the fronts are, how do we know what

KIND they are?

• It depends on which direction the line you just drew is moving…

• If colder air is coming in, it is a cold front.

• If warmer air is coming in, it is a warm front.

So how do I know which way the front is moving?

• Look at the winds on both sides of the front.

• On one side, the winds will be “pushing” the front.

• On the other side, the winds will be retreating from the front.

Pop Quiz!

• A pressure center (Low or High) is located at the “corner” of these two fronts.

• What kind of pressure center is it?

Almost There!How do you know if it is a cold

or warm front?• Put yourself in front of the front.• Ask yourself: “Self, what kind of air am I in

now: warm or cold?”• Then ask yourself: “Self, what kind of air

will I be in after the front passes?”• If it got cooler, it is a cold front.• If it got warmer, it is a warm front.

Warmer air

Cooler air

I’m in warm air now

Warmer air

Cooler air

Hey it got colder!

It must be a cold front

What about the Eastern “Leg”?

Warmer air

Cooler air

Boy, it’s pretty cool

Warmer air

Cooler air

Aah! Nice and warm.

It must be a warm front

What kind of weather do you get from each?

Cool Air

Warm Air

Warm air rises because it is light & fluffy.

Cold Front

A Cumulonimbus Cloud“Thunderhead”

Rain

20-50 miles

Storms are very small, 20-50 miles or so and last only a brief time.

Right now it’s nice and warm

Gadzukes! It got cold!

Warm Air Cool Air

Frontal interface

Warm is light and fluffy and it likes to float!

Warm Air Cool Air

First come the Cirrus

Which way is the weather coming from?

It’s pretty cool nowSuch pretty cirrus clouds!

Hmmm, the clouds are getting low

The warm front gets closer…

Clouds get lower and thicker

Darn! It’s starting to drizzle.

Lower and thicker then gentle rain for a long time.

It’s much warmer now

Warm Front