Learn This: How To Read Mountain Weather
The Southeast Buttress of Cathedral Peak in Tuolumne Meadows. Grand Teton. The Diamond on Colorado’s Longs Peak. Some of the country’s most compelling routes require a trip into the alpine, where the sweat poured into frequently grueling approaches is paid back in spectacular summit views. But it takes more than solid quads, healthy lungs, and good climbing technique to ensure success on an alpine climb; it also takes a healthy respect for mountain weather.
Climbers should consider wind speeds, the chance of snow or rain, and the forecasted highs and lows when planning any trip into the mountains. But most importantly, according to meteorologist Joel Gratz, is mitigating your chance of getting struck by lightning. “If the temps drop a little bit, if the wind picks up, if it starts to precipitate, usually you have some time to extricate yourself from the situation,” Gratz said. “But once the storm is close enough to produce lightning, you’re one bolt away from being injured or killed, and that can happen in a second.”
Here are his tips for respecting the weather:
1. Before you go
Check the point forecast
Instead of looking at the forecast for the nearest town, examine the forecast for the actual location of your climb. The National Weather Service’s website lets you click an exact point on a map, or you can enter lat/long coordinates into the search bar. The point forecast is likely more accurate than using the nearest town, which can be thousands of feet lower than your climb.
Check the hourly forecast
Take a finer-grain look by checking the hourly forecast. At weather.gov, you can find it by clicking on “Hourly Weather Graph,” which tells you when the winds will likely pick up, when the temperature is expected to peak, and when thunderstorms should begin to build. Plan to be up and off your objective at least an hour before the forecast calls for storms to move in. Also, pay attention to a rapidly changing forecast. If the chance of storms differs radically from day to day leading up to your climb, that’s a sign that meteorologists may not have a lot of confidence in the forecast.
Check the radar
These are not especially accurate in the mountains, owing to the fact that the peaks can block the radio waves. The first reading may not give you much useful intel for your climb, but checking regularly and learning the patterns will be useful later. Notice the direction weather is moving in from, and you may start to see systems the more frequently you head into the high mountains. For example, storms from the north may drive colder winds than those moving in from the southwest.
Chat with locals
People who frequently climb in an area may have valuable beta about how the weather forecast routinely differs from conditions on the ground. Some canyons may funnel winds more strongly than predicted, or shaded walls may be much cooler. Call a local gear shop or guiding company for insight.
2. In the field
Watch the sky
Once you’ve committed to the climb, pay attention to the weather. Look for signs that the forecast is right or wrong or moving in quicker, and adjust your plans. Take into account whether you have a good vantage point. For example, a view to the east from a climb in Rocky Mountain National Park is not especially helpful since weather tends to move in from the west. If your view to the west is blocked, be aware that it may be easier for a weather system to sneak up on you.
Know your clouds
They won’t all produce a lightning bolt. You should be worried about rising cumulous clouds, which are puffy and simultaneously hard-edged, like the bicep of a bodybuilder. As the building cloud gets taller, it becomes capable of producing lightning, rain, and hail and takes on a new name: cumulonimbus. High, wispy clouds, known as cirrus, and low shelf-like clouds, known as stratus, are less of a concern. Stratus clouds can produce light precipitation, but they won’t produce lightning. Graupel (small spheres of snow) are also a sign of electrical activity.
3. Back at home
Log your observations
If you plan on climbing frequently in the area, it’s a good idea to write down what you observed. Note the weather forecast, what the radar looked like, and what actually happened so you can look for patterns in the future.
Joel Gratz is the weather nerd behind opensnow.com, the go-to website for those in search of powder. Gratz, who studied mountain weather as a grad student at the University of Colorado at Boulder, hikes, climbs, and bikes when there’s no snow to be skied.