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Weather Balloons

Notes:

Another tool to look at what is happening aloft is the data returned by weather balloons. These are information loaded, but there are a couple of points that can be easily extracted. The horizontal scale is temperature in C. The vertical scale is pressure with altitude in smaller numbers.

Note the two black lines. This is the dewpoint (left) and temperature(right) plotted for each altitude.

Nominally temperature decreases with altitude. The example on the left shows this. Note that the example is not from Oakland.

The example on the right is more typical of the Bay Area. The temp reverses sharply and increases by almost 10 degrees C (almost 18 degrees F). The dewpoint also sharply drops indicating much dryer air. The top of the clouds would be not higher than about 800 m (2600 feet). At Coe or Fremont Peak you would prefer the inversion to be lower.

Note also the wind rose on the right. This indicates the direction and intensity of the wind. At the point of the inversion the wind direction changes from west to north. The wind speed is not much higher in this example.