Historical weather information is available and can help us with estimations of future weather conditions. There is data from Hatteras on Cape Hatteras, and from Manteo Airport on Roanoke Island which lies between Cape Hatteras and the mainland. Kitty Hawk is close by.

When faced with the large amount of data available, meteorologists must find a way to bring it into manageable form. This involves thinking first and acting later.

The thinking steps are:

Deciding WHICH of the available data values will be useful for weather prediction.
Deciding HOW to record them in a way that is easiest to use.

'WHICH' data values will depend on your focus, whether it is temperature, wind speed, visibility, etc.
'HOW' to record data in a simple fashion involves transferring selected data to:
(1) a carefully designed table and
(2) creating charts and graphs from that data in an easy-to-read form.

Here is a possible chart graphing maximum and minimum temperatures on December 17 at Hatteras and Manteo. The corresponding table is also shown.

Examine the "big picture" first. Look at the shape of the graph and any trends before looking at exact values in the table.

What is noticeable in "big picture" terms?
The green Manteo lines follow the same profile in every year except 2001. Wonder why?
The exception year for Hatteras seems to be 1998 when the maximum and minimum lines veer apart.
The maximum temperatures for both locations stay very close to each other, more than the minimums do.

In 2002, the lines end at the closest point in the entire seven-to-nine year range. This can be confirmed by looking at values in the table.

After looking at this graph, and maybe checking temperatures for adjacent dates, a justifiable temperature prediction for December 17, 2003 can be made. Will it be cooler? Or warmer? Make the prediction then wait and see. Good luck!

Since dew point varies with the humidity and temperature of the atmosphere, try superimposing the recorded dew point values on the temperatures graph above to demonstrate the relationship and help with the forecast. A dew point calculation chart gives further illustration.

The wind speed, visibility, and precipitation predictions can be made using these same graphing methods.

A note about graphing: Graphs can always be prepared by hand with gorgeous results by artistically gifted students, but a computer spreadsheet program is highly recommended. The convenience and availability of multiple chart copies encourages the "risk taking" involved in trying many different approaches on the way to a prediction. The graphs in this activity were prepared and embellished using the Microsoft Excel program.