Weather Notebook
Bryan Yeaton

Smell of Weather
Thu Dec 30, 2004

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We can see it; we can certainly feel it; we can even hear it but can we actually smell weather? Hi, Im Bryan Yeaton for The Weather Notebook.

Were not just talking about skunky, polluted air, or foul emissions from swamps and other such places. Or even the smells that waft in from the sea breeze, or from a field of newly-mown hay. But for ages, certain people claim to be able to predict weather based on their sense of smell. Perhaps you have heard:

Flowers smell best just before a rain. Or:

When ditches and ponds offend the nose, look for rain and stormy blows.

Many weather sayings are, um, misguided, but others do have a ring of truth like the ones we just quoted. Heres why:

First, warm and humid air enhances our sense of smell, because the humidity carries odor molecules to our noses. And humidity increases as the threat of rain increases. Lowering barometric pressure and rising air currents are also indicators of likely precipitation, and they both enhance the transmission of natural smells from far afield.

When the wind blows from a given direction with an approaching weather system, we may smell the gases given off by distant wet plants and soil long before the rains move over us.

Particular smells associated with a change in wind direction may also indicate coming weather changes, though this is often a local effect. For example, if an East wind brings rain and a swamp lies to your east, the smell of the swamp may be a good indication of rain in the near future.

So the next time you hear someone say, "It smells like rain", you might keep that umbrella handy.

Thanks to our contributing writer, meteorologist Keith Heidorn. Funding for The Weather Notebook comes from Subaru of America. We are produced by the Mount Washington Observatory.

Today's Links

Man and Weather: The Smell of Rain

STORMWARN: Weather Lore

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