Cloud Reading: Weather Observation
In California, late fall usually means the door to Pacific storms begins to open wide, bringing snow to the highlands. Regardless of where you live, the weather affects your daily life, but it’s especially important for people who spend time outdoors. Skiers and other winter sports enthusiasts will naturally listen to the latest weather reports before heading to the heights. But once they’re slipping through the blanket of glass or walking in potentially bad weather, they may not have a radio or television or reliable cell phone service available to monitor the storm that forecasters said was coming.
However, approaching storms give hints of their imminent arrival at least several hours in advance. The following hints can help you decipher those clues:
“A Field Guide to the Atmosphere” by Vincent J. Shaefer and John A. Day (Houghton Mifflin).
As the title suggests, this book is about more than weather forecasting. Like all the books in Peterson’s field guide series, its primary focus is identification; in this case, clouds, rainbows, glories, halos and other atmospheric phenomena. For this, it has numerous drawings, as well as 336 black and white photographs and 32 in color.
Because the atmosphere is not just something to identify, but also a constantly changing system to observe, the book devotes much space to discussing the processes at work in the ocean of air. It’s as much for the skier who wonders how a high, icy cirrus cloud can halo the sun as it is for the snow camper who wants to know if he’ll have to get out of his tent the next morning. .
“Resisting the Desert” by William E. Reifsnyder (Sierra Club Books).
The subtitle of this book is “The Sierra Club Guide to Practical Meteorology.” It is written with the outdoor recreationist in mind. The first part of the book is a basic course on the why of winds and storms. Of particular interest to the future forecaster is a table showing how different weather conditions – pressure (for which you will need an altimeter/barometer to measure) wind, clouds, precipitation, temperature, humidity and visibility – change as approach systems and passed. By the way, the chapter on “Weather Hazards,” especially its discussion of wind chill, hypothermia, and avalanches, should be of particular interest to the skier.
The second part deals with general weather patterns for various regions of the United States and Canada, including the Sierra Nevada, and generally mild, wet winters produce good skiing conditions.
Pocket Weather Trends (Weather Trends Inc.)
This device is the most practical of the three forecasting aids. It looks like a simple slide rule. A slide rack has 6 boxed areas on its front with photos and descriptions of different types of clouds. Each box has eight compass directions. Each slide, one for each of several regions, has a black mark in the middle that is aligned next to the wind direction within the box that corresponds to the cloud type observed overhead. Then, in two horizontal windows, one from November to April and the other from May to October, the slide will show you the forecast for the next 12 to 36 hours.
All of these books are available on Amazon.
In addition to books or charts, there are portable weather instruments that a recreationist can take with them. Accurate measurements of weather conditions can take the guesswork out of forecasting. Companies such as Kestrel, Ambient Weather, Speedtech, Weather Mate, and Davis Instruments make portable devices that can measure temperature (current, maximum, and minimum), pressure, elevation, wind speed, relative humidity, dew point, and other measures. Also, they are all water resistant or waterproof. These are available directly from the manufacturer, recreation stores, or online.
