Weather in the mountains changes fast. The rapid changes in elevation, the valleys and peaks, and even vegetation all create micro climates that can exchange latent heat in surprising ways. Additionally, mountains uplift winds from low-lying plains, which can help create precipitation. Knowing how to gauge changes in weather is a useful tool for any mountain hiker, and when it comes to mountain climbing, it's a skill that might save your life.
Instructions
Difficulty: Moderately Easy
Clouds
Step 1
Know the basic types of clouds: cumulus, stratus, cirrus and nimbus. Fluffy cumulus clouds form in the lower atmosphere, 6,500 feet to 20,000 feet. Stratus and cirrus clouds are thin and layered, and typically are found above 20,000 feet. They are composed predominantly of ice crystals, which also cause sun dogs and haloing. Nimbus, from the Latin word meaning cloud or rain, describes clouds that are about to burst.
Step 2
Watch for cumulonimbus clouds--large, vertically developed, cumulus clouds with swollen, dark underbellies. Also known as thunderheads, they often bring violent storms. If you see cumulonimbus clouds flocking in from the horizon, and you have yet to reach the summit, it would be wise to turn back.
Step 3
Stay aware of cumulus clouds in general. Even if they are white and fluffy, speckling distant valleys with shadow, pay attention. As cumulus clouds aggregate above mountains and peaks, they could begin to turn darker, and hail could be on the way.
Step 4
Gauge airflow by the direction of cirrus clouds. Typically, cirrus clouds occur in fair weather. High in the atmosphere, and stratified along isotherms and pressure gradients, they mark air currents. This can help you gauge the movement of the weather, and from which direction the weather is approaching.
Step 5
Watch for distant rain. From a distance, rain appears as dark wisps, a veiling and graying of the landscape. If you see cumulus clouds with this appearance, and they are moving toward you, act quickly.
Winds and Pressure Differentials
Step 1
Keep track of the wind. If you're hiking at tree line, observe the movements of deciduous leaves. Low pressure turns leaves over; there is a distinct noise and visual patterning to this effect. When people say they can "smell the rain" coming, this is often low pressure bringing down an accumulation of ozone from the ionization occurring in the clouds. If you are above tree line, watch another hiker's hair. It will rise and fall with lowering pressures.
Step 2
Feel the temperature of the wind. As you climb higher, note the temperature of the wind, its force and frequency in gusts. A cold wind might bring precipitation, especially if it is moving clouds.
Step 3
Be aware of the landscape. High ridges--knife-edge ridges--often batter winds between them. In the heat of the afternoon, winds typically should be rising. If it is cold and the atmosphere is inverted (which could indicate wind), the wind might change direction.
Step 4
Use your surroundings. Northern aspects (mountainsides facing north, typically on the southern side of a valley) will be colder, wetter and populated by more evergreens. Southern aspects (those areas facing south) will be warmer, drier and populated by deciduous and hardwood forests. This means convective currents rise from the southern aspects. Paragliders take advantage of this fact, rising over the north side of a valley and descending from the south.
Step 5
Remember, hail can fall in the mountains, even in summer. When falling rain freezes in flight, hail forms. Hail can be accompanied by thunder and lightning.
Tips & Warnings
Always check local weather sources, on the Internet or radio stations, before heading out. Be humble. Often hikers who get caught in the weather took a risk they could have avoided. Pay attention to your feelings. Most people can learn to gauge weather with time and practice. Trust your gut feelings. The inner ear and sinus cavities can readily detect pressure changes, so "listen" to your body.
Always camp below tree line. Waiting out the weather can be a fun way to spend an afternoon. Remember, it is always better to be late in this world than early in the next.
Instructions
Difficulty: Moderately Easy
Clouds
Step 1
Know the basic types of clouds: cumulus, stratus, cirrus and nimbus. Fluffy cumulus clouds form in the lower atmosphere, 6,500 feet to 20,000 feet. Stratus and cirrus clouds are thin and layered, and typically are found above 20,000 feet. They are composed predominantly of ice crystals, which also cause sun dogs and haloing. Nimbus, from the Latin word meaning cloud or rain, describes clouds that are about to burst.
Step 2
Watch for cumulonimbus clouds--large, vertically developed, cumulus clouds with swollen, dark underbellies. Also known as thunderheads, they often bring violent storms. If you see cumulonimbus clouds flocking in from the horizon, and you have yet to reach the summit, it would be wise to turn back.
Step 3
Stay aware of cumulus clouds in general. Even if they are white and fluffy, speckling distant valleys with shadow, pay attention. As cumulus clouds aggregate above mountains and peaks, they could begin to turn darker, and hail could be on the way.
Step 4
Gauge airflow by the direction of cirrus clouds. Typically, cirrus clouds occur in fair weather. High in the atmosphere, and stratified along isotherms and pressure gradients, they mark air currents. This can help you gauge the movement of the weather, and from which direction the weather is approaching.
Step 5
Watch for distant rain. From a distance, rain appears as dark wisps, a veiling and graying of the landscape. If you see cumulus clouds with this appearance, and they are moving toward you, act quickly.
Winds and Pressure Differentials
Step 1
Keep track of the wind. If you're hiking at tree line, observe the movements of deciduous leaves. Low pressure turns leaves over; there is a distinct noise and visual patterning to this effect. When people say they can "smell the rain" coming, this is often low pressure bringing down an accumulation of ozone from the ionization occurring in the clouds. If you are above tree line, watch another hiker's hair. It will rise and fall with lowering pressures.
Step 2
Feel the temperature of the wind. As you climb higher, note the temperature of the wind, its force and frequency in gusts. A cold wind might bring precipitation, especially if it is moving clouds.
Step 3
Be aware of the landscape. High ridges--knife-edge ridges--often batter winds between them. In the heat of the afternoon, winds typically should be rising. If it is cold and the atmosphere is inverted (which could indicate wind), the wind might change direction.
Step 4
Use your surroundings. Northern aspects (mountainsides facing north, typically on the southern side of a valley) will be colder, wetter and populated by more evergreens. Southern aspects (those areas facing south) will be warmer, drier and populated by deciduous and hardwood forests. This means convective currents rise from the southern aspects. Paragliders take advantage of this fact, rising over the north side of a valley and descending from the south.
Step 5
Remember, hail can fall in the mountains, even in summer. When falling rain freezes in flight, hail forms. Hail can be accompanied by thunder and lightning.
Tips & Warnings
Always check local weather sources, on the Internet or radio stations, before heading out. Be humble. Often hikers who get caught in the weather took a risk they could have avoided. Pay attention to your feelings. Most people can learn to gauge weather with time and practice. Trust your gut feelings. The inner ear and sinus cavities can readily detect pressure changes, so "listen" to your body.
Always camp below tree line. Waiting out the weather can be a fun way to spend an afternoon. Remember, it is always better to be late in this world than early in the next.
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