METR 361 Spring 2014

Composite Chart Lab

Assignment:

On an eastern U.S. base map, you will construct a composite chart using the paper maps weather in a real case, given in this lab. For each map located on the website, identify just those parameters favorable for severe thunderstorms. To do that, use symbols similar to the ones used by Miller. For example, Miller used different kinds of arrows for jet streams. You could use arrows that are different colors for different levels. In the sample composite chart below, a red arrow is from 850 hPa while a blue arrow is from 200 hPa. You must add the maximum wind speed in knots to each arrow, as shown. Draw them right on your paper maps.

For other symbols, you should devise different ones to represent the different favorable parameters you find. Use the sample chart below for ideas and think of others on your own. You get to figure out how to represent in symbols all the important ingredients on each map. You must include a key showing the symbols you made up and the parameters they mean.

Once you have all the maps analyzed, transfer ONLY the symbols to the blank base map in the same geographic positions. This becomes your composite chart. Then go to the SPC website and read the discussion for today’s outlook. On a separate piece of paper, using a format similar to the SPC discussion, you write an assessment of what your composite map means for this specific case. In that assessment, identify the important ingredients you found for this severe weather case and explain what each one brings to the severe weather potential. Also, if any important ingredients favorable for severe weather are missing, you need to put that fact in your discussion. Your discussion is only for 00Z, the time of your maps.

Your analysis maps are as follows (all are 00Z):

US surface plot, 850 hPa, 700 hPa, 500 hPa heights, and 200 hPa.