Friday, August 22, 2008

Fay Bringing Historical Rain Totals

I tell you, I look at the CoCoRaHS maps each day across Florida and just can't believe what I am seeing!

Click on Florida for today and then look at Volusia County. The view lets you see surrounding counties too.

There are a half-dozen reports between 6.50-11.50 inches and that was as of 6:30am MDT this morning.

Fay is slowly drifting west and may go back over water as it parallels the panhandle over the next 48 hours.

Depending on the exact track, it could make 1 or 2 more landfalls as it follows the panhandle's irregularly shaped coastline.

Elsewhere, most of the country is quiet and seasonal.

Today's Lesson

In weather class, we learn about heat capacity and specific heat.

The heat capacity of a substance is the ratio of the amount of heat energy needed to make a corresponding temperature rise.

The heat capacity of a substance per unit mass is called specific heat.

In other words, specific heat is the amount of heat needed to raise the temperature of one gram of a substance by 1° celsius.

If we heated 1 gram of pure liquid water on a stove, it would take about 1 calorie* of heat to raise the temperature by 1° celsius.

*a calorie is a measure of heat

So therefore, pure water sets the standard for measuring specific heat.

Soil would only need 0.2 calories of heat, so it has a specific heat that is 1/5 less than water.

What this means is that water heats and cools slowly. It has an enormous capacity for storing energy than most other substances.

Why is this important to weather? Because 3/4 of our planet is covered by water.

1 comment:

  1. Chris,

    The specific heat of pure water is 1.0 Does that apply to all forms of water (solid/liquid/gas)?