Drawing an Isotherm

Drawing Isotherms

Welcome to the "Drawing Isotherms" learning page! Here, you'll learn how to analyze surface temperature patterns by drawing isotherms, which are contours of equal temperature. Follow the step-by-step directions below to practice this essential meteorological skill. We'll also include an interactive site where you can practice making isotherms and identifying weather fronts.

What are Isotherms?

Isotherms are lines drawn on a map connecting points that have the same temperature. They help meteorologists visualize temperature patterns and identify areas of similar temperatures.

Steps to Draw Isotherms

1. Gather Your Materials:

   • Surface temperature data (map or chart)

   • Pencil

   • Red medium felt-tip pen

   • Eraser

2. Analyze the Surface Temperature Pattern:

   • Look at the surface temperature map and draw contours (lines of equal temperature) that are multiples of 5°F (e.g., 50°F, 55°F, 60°F, etc.).

3. Draw Preliminary Isotherms with Pencil:

   • Using a pencil, start by identifying the temperature values at different points on the map.

   • Begin drawing dashed lines (- - - - - - - - -) that connect points with the same temperature. 

     • Note: do not draw over numbered values rather lift your pencil over the number and then continue drawing on the other side.

   • Ensure that each line smoothly transitions between the points, reflecting the temperature gradient.

4. Finalize with a Red Medium Felt-tip Pen:

   • Once you are satisfied with the pencil lines and weather fronts, trace over the isotherms with a red medium felt-tip pen.

   • Draw the isotherms as dashed lines for clarity.

   • Trace the weather fronts with the appropriate colors and symbols.

5. Identify and Draw Weather Fronts:

   • Analyze the temperature gradients and patterns to identify any weather fronts (boundaries between different air masses).

   • Draw the weather fronts using appropriate symbols and colors:

     • Cold Front: Blue line with triangles pointing in the direction of movement.

     • Warm Front: Red line with semicircles pointing in the direction of movement.

6. Label Each Isotherm and Front:

   • Clearly label each isotherm with the corresponding temperature value (e.g., 50°F, 55°F, etc.).

   • Place the labels along the lines at regular intervals.

7. Erase Pencil Marks:

   • After finalizing the isotherms and weather fronts with the pen, carefully erase all the pencil marks.

   • Ensure that the dashed lines, weather fronts, and labels remain intact and visible.