Surface observations are extremely important for a variety of reasons. First off, some people absolutely need these observations to perform their tasks safely. You wouldn’t want a pilot to fly into a foggy airport now, would you? They also are critical for successful forecasting, especially in the short term. And of course, it’s important to simply know what the weather is like in the present!
Here, I will explain some basics. You can find more detail in a presentation created by Robert Houze, one of my professors from the University of Washington.
Above is an example of a surface observation. Let’s go through each section and explain it in more detail. Temperatures are in Fahrenheit.
Pressure:
The pressure observation is the last three digits of the observed pressure, with the last digit being to the right of the decimal point. Based on the pressure reading, meteorologists either add a 9 or 10 beforehand to determine the appropriate pressure reading for that station. For example, the pressure above is 1013.8 mb, not 138. However, if the pressure reads something like 999, meteorologists would add a 9 instead of a 10, giving a pressure of 999.9 mb, as that is far more realistic than 1099.9 mb.
Determining whether to add a 9 or a 10 is pretty easy, and although there are situations where there could be an overlap (for example, 400 could correspond to 940 for a tropical cyclone or 1040 for a strong ridge of high pressure), you can just look at nearby stations and other indications on the map to get an idea of what the prefix is.
Wind:
Wind is not measured by numerical units. Instead, we have barbs. Small barbs are equal to 5 knots, while large ones are equal to 10 knots. When it gets really windy, we also use flags, which are equal to 50 knots. The diagram below shows a nice example of some different wind barbs.
Cloud Cover:
Cloud cover is denoted by that circle at the middle. In the example above, it is black, but it is not always black. The chart below is pretty self explanatory. “Sky obscured” means fog.
Current Weather:
Temperature, wind, and all that jazz are all very nice, but we want to know what’s actually happening at the station. And that’s where the current weather symbols come in. These symbols generally let us know what’s happening precipitation-wise. Take a look below.
If none of these are happening (ex: the sky is clear and sunny and there are no crazy dust devils or haboobs going on), I wouldn’t be surprised if this part is simply omitted.
Congratulations! You can now read station models. Now, put your knowledge to use!