Identify Pennsylvania on the map. Notice that there are five stations around Pennsylvania including one in the western part of it. Others are in western New York, northern Virginia, eastern Maryland, and northeastern New Jersey/New York City. All five stations are cloudy (except Maryland has missing data), windy and rainy. Can you explain why winds are from different directions but going around the same location?

Identify Pennsylvania on the map. Notice that there are five stations around Pennsylvania including one in the western part of it. Others are in western New York, northern Virginia, eastern Maryland, and northeastern New Jersey/New York City. All five stations are cloudy (except Maryland has missing data), windy and rainy. Can you explain why winds are from different directions but going around the same location?

The hint to this answer is in the following statement:

Focusing on the station model for New York City (can you find NYC?), we see that the temperature is 64° F and the dew point temperature is 60° F. The sea-level pressure at New York City is 965.1 mb (more on this shortly). The winds are strong and from the east, and New York is experiencing overcast cloud conditions with light rain as Superstorm Sandy passes just to its south. Interestingly, not far away in Washington, DC, the wind direction is from the northwest. Winds around low pressure in the Northern Hemisphere blow in a counterclockwise direction and cause clouds and rain, as in this case. This helps us understand why we should decode the sea-level pressure as 965.1 mb, consistent with cloudy, stormy low pressure, instead of 1065.1 mb, which would be very high pressure. Use the activity below to decoding real observations.