In the backcountry, weather forecasting is an important skill for the hiker to have. Learning the basics is an important first step.
Previously, I posted a short article about using your GPS to monitor barometric pressure while in the backcountry and think it worthwhile to cover a few other topics concerning in-the- field observations starting with thunderstorms.
Let me begin by stating that forecasting begins at home. Monitor your local cable channels and radio stations to get a broad, general idea of the weather conditions before an outing. Further refine that information by checking internet sources such as Weather Underground and the National Weather Service’s site.
Next familiarize yourself with book on the subject by leaders in the field. My “go to” reference is Northwest Mountain Weather by Jeff Renner. Renner is a professional meteorologist and broadcaster, an outdoorsman and flight instructor. He has several other books in print that are worth checking into.
Northwest Mountain Weather provides a superb overview on how the “weather works” in the Pacific Northwest. Uniquely focused on this region, the book provides an overview of climate and weather, local weather patterns as well as snow and avalanche conditions and provides many charts and data sources.
My personal favorite is Chapter Seven, “Field Forecasting Guidelines,” which identifies what to watch for and monitor while in the backcountry.
Forecasting a thunderstorm in the field
The dark clouds of a thunderstorm provide a strong sense of mass and energy. They can be seen a long way off. Avoid them when possible. As a storm develops you will notice that the clouds may change shape, grow taller and darker. In many cases an anvil shaped cloud growing tall and developing a distinct leading edge may be observed. This is a sign that a storm is on the way.
Lightning is the predominant killer associated with a thunderstorm. Roughly 40 people are killed each year and approximately 240 are injured. Visit the National Weather Service’s site for more information about lightning safety.
The ideal action to avoid the danger of a significant storm is to get out of the weather. Leave the field for the safety of a building or car. Caves can provide shelter but must be deep and dry. A shallow cave offers almost no protection.Renner’s guidelines include a brief list of what to Do and what Not to do in the event of a thunderstorm: “Do watch for cumulus showing strong upward development. Do choose a campsite uphill from valley floor. Do get away from exposed areas, pinnacles, peaks. Do get away from water. Do seek low ground in open valleys and meadows. Do move at once if hair or scalp feels tingly. Do not stand under trees.”
Wilderness Survival trainer Peter Kummerfeldt in his book Surviving a Wilderness Emergency amplifies Renner’s comment by adding the following:
“Be proactive – don’t wait until you are getting wet to suspend outdoor activities. Don’t be connected to the tallest object in the area. If caught outside, move into low trees of even height and stand away from tree trunks. Stay away from isolated trees. Water is a great conductor of electricity – get out of the water at the first sign of a storm developing.” For more information, visit Kummerfeldt’s website at www.outdoorsafe.com.
Thunderstorms have the potential to deliver large quantities of water. Look for higher ground and stay out of stream beds that may flood significantly and without warning.
The key is to stay alert and make a plan of action when a storm approaches.