Monday, December 29, 2014

Weather Lore -- from "Enter the Forest"

[Nyerges has been teaching outdoor skills since 1974.  He is the author of many books, including “Testing Your Outdoor Survival Skills,” “How to Survive Anywhere,” “Enter the Forest,” and others. Information about his books and classes can be seen at]

Aside from consulting with newspapers, the weather service, and such online services as Weather Underground, you should learn to make your own weather observations, and learn to interpret what you see.  If nothing else, this helps to increase your awareness of the environment and keeps you alert.

Birds perch more and fly lower before a storm because the low-pressure air makes it harder to fly.

A barometer – either store-bought or home-made – is a good tool for determining if there will be clear days or rain ahead.  A rising barometer indicates decreasing air pressure and clear weather, while a rapidly falling barometer sometimes forecasts rain, snow, or other stormy weather.

Though you might have a barometer on your wall at home, most people do not carry a barometer with them into the wilderness areas.  However, many people do carry altimeters (sometimes built into their wrist watches), and these are essentially barometers.  First, you need to know where you are on  your map, and your altimeter needs to be accurate.  Then, over the course of a day or so, if our altimeter shows a higher elevation than is accurate, it means the pressure is falling and this could indicate that a storm is coming.  If the altimeter shows a lower elevation than what the map indicates, then the pressure is rising and you have a general indication of clear or clearing weather.

The key here is an accurate altimeter, and your observation of a change in the altimeter while you were at the same location.

Dew on the grass at night or early morning can be a sign of fair weather, and dry morning grass can foretell rain or an overcast day.  However, in some areas where it is very dry, you may not get morning dew even though  the day will be clear.

The presence of a red sunrise or sunset is also a good general indicator of the weather to follow.  A red sunset generally indicates fair weather, and a red sunrise may foretell rain within 48 hours.  A simple rhyme makes it easy to remember:  “Red sky at night, sailors delight; red sky in morning, sailors take warning.”

Learning to read the clouds can be another skill for short-term weather forecasting.

For example, cumulus clouds are the puffy, flat-based, cauliflower-like clouds which are constantly changing. They mean fair weather followed by clear nights. However, if they begin to stack up into cumulonimbus clouds, that means rain or snow is on the way.

Cumulonimbus clouds result from strong vertical air currents.  These are the most familiar thunderheads, with winds often molding the tops into an anvil form.  Their based may almost touch the ground in the mountains, and violent updrafts can carry the tops to 75,000 feet.  In their most violent form, they can produce tornadoes.  Usually a sign of approaching storms, these cumulonimbus clouds will drop rain or snow, and sometimes hail.

There are many other natural signs which will tell you about upcoming weather systems. Most of these signs are fairly logical once you understand the mechanisms at work.  One of the best books on this subject is Eric Sloane’s illustrated “Weather Book.” Sloane gives the reader a basic understanding of the principles which control weather, and his beautiful drawings make the subject easy to grasp.

I have also learned a lot from Ellsworth Jaegar’s “Wildwood Wisdom” and from the weather section of most Boy Scout manuals.

Observing short-term weather signs is a good way to increase your awareness. When planning your trips, take advantage of all the modern resources.

Once while discussing weather with meteorologist Dr. George Fischbeck, well-known to Southern California TV audiences, he told me that he is very suspect of the long-term weather projections of a week to 10 days. “Weather is a very dynamic thing,” he told me. “No one can accurately predict the weather beyond more than 48 hours.”


How to determine weather conditions by observing a rope that was hung from a tree limb:

If the rope is:
The weather condition is:

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