Weather & Hazards

Reading the sky, avoiding natural dangers, and handling wildlife encounters.

1. Reading Clouds

Fair weather indicators:

• High, thin cirrus clouds — generally fine weather for the next 12–24 hours (unless increasing and thickening, which indicates a front approaching)
• Small, puffy cumulus (fair-weather cumulus) — flat bases, limited vertical growth. Normal summer day clouds.
• Clear sky at sunrise

Deteriorating weather indicators:

• Cirrus thickening to cirrostratus (high haze, sun gets a halo) — a warm front is 12–24 hours away. Rain is likely.
• Lowering cloud base — clouds getting closer to the ground means moisture is increasing.
• Cumulus clouds growing tall (towering cumulus → cumulonimbus) — thunderstorms developing. When the top flattens into an anvil shape, a severe storm is imminent.
• Wind shifting or increasing — a front is passing through.
• A ring or halo around the sun or moon — rain likely within 24–48 hours.

Quick rules:

• "Red sky at night, sailor's delight" — actually works in mid-latitudes. Red sunset often means dry air approaching from the west.
• "Red sky in morning, sailor's warning" — moisture to the east (already past) reflects red light. Weather systems typically move west-to-east.
• Rapidly dropping clouds + rising wind = seek shelter now.

2. Wind & Pressure

• Sudden calm after wind can indicate the center of a storm passing — more wind may follow from a different direction.
• Shifting wind direction (especially counterclockwise in Northern Hemisphere) indicates an approaching low-pressure system and likely rain.
• Increasing wind speed + dropping temperature = cold front approaching. Often brings brief, intense rain followed by clearing.
• Smoke rising straight up = stable, high pressure, good weather.
• Smoke that curls down and stays low = low pressure, precipitation likely.

3. Lightning

Lightning kills more outdoor recreationists than any other weather event.

Estimating distance:

Count seconds between flash and thunder. Divide by 3 (metric) for kilometers, or by 5 (imperial) for miles. If under 10 seconds (3 km / 2 miles): you are in the danger zone.

If caught in a lightning storm:

• Get off ridges, peaks, and exposed high ground immediately.
• Avoid: isolated tall trees, open water, metal fences, power lines, cave entrances (ground current).
• Seek: a low area among uniform-height trees (a forest, not a lone tree). A valley or depression.
• Lightning crouch: If you cannot reach safe ground, crouch on the balls of your feet, feet together, head tucked, hands over ears. Minimize contact with the ground. Do NOT lie flat.
• If in a group: spread out at least 5 meters apart. This prevents a single strike from hitting everyone and ensures someone can help the others.
• Remove metal-frame packs and set them away from you.

4. Flash Floods

• Flash floods can occur with little or no warning, even in areas where it's not currently raining (rain may be falling upstream).
• Never camp in a dry riverbed or wash. These can fill in minutes.
• Warning signs: sudden muddy or rising water, roaring sound from upstream, debris floating on water that was clear.
• If caught: move to high ground immediately. Do not try to cross rising water. Just 15 cm (6 inches) of fast-moving water can knock you down. 60 cm (2 feet) can float a car.
• Slot canyons are extreme flash flood hazards. Check weather forecasts for the entire watershed before entering. Do not enter if rain is possible anywhere upstream.

5. Avalanche Awareness

Avalanches kill experienced mountaineers. Without formal training, the best strategy is avoidance.

High-risk terrain:

• Slopes between 30° and 45° (steepest risk zone)
• Leeward slopes where wind-deposited snow accumulates
• Recently loaded slopes (heavy snowfall in the last 24–48 hours)
• Convex slopes (roll-over terrain)
• Sun-exposed slopes in spring (wet avalanches)

Warning signs:

• Cracking or "whumpfing" sounds underfoot — the snowpack is collapsing
• Recent avalanche debris on similar slopes
• Rapid warming or rain on snow
• Wind-loaded pillows of snow

If caught:

• Try to move sideways off the slab.
• If swept off your feet, fight to stay on the surface — swim aggressively.
• As the slide slows, create an air pocket in front of your face with your arms.
• Try to push a hand toward the surface.
• Once the debris sets, it's like concrete. You will not be able to dig yourself out. Conserve air and oxygen.

6. Bears

Prevention (most important):

• Make noise while hiking — talk, clap, call out on blind corners.
• Store food and scented items (toothpaste, sunscreen) in bear canisters or hung 4+ meters high, 1.5 meters from the trunk, and 30+ meters from camp.
• Cook and store food 100+ meters downwind from your sleeping area.
• Never approach or feed bears.

If you encounter a bear:

• Stay calm. Do not run. Bears can run 50 km/h — you cannot outrun them.
• Identify the species if possible. Response differs between black bears and brown/grizzly bears.

Black bear encounter:

• Make yourself look large. Stand tall, wave arms slowly.
• Speak in a firm, calm voice. Back away slowly.
• If it charges: stand your ground. Most charges are bluffs.
• If it makes contact: fight back. Hit the nose and eyes. Use rocks, sticks, anything. Black bears attacking humans are usually predatory — playing dead does not work.

Brown/grizzly bear encounter:

• Speak calmly. Avoid direct eye contact. Back away slowly.
• If it charges: stand your ground until the last moment (most charges are bluffs).
• If it makes contact: play dead. Lie face down, legs apart, hands clasped behind your neck. Spread your legs to resist being flipped. Stay still even if it mouths or swats you. Most grizzly attacks are defensive — the bear will leave when it no longer perceives a threat.
• Exception: If the attack continues for more than a few minutes or the bear starts eating, it has turned predatory. Fight back with everything you have.

Bear spray:

If you carry bear spray, keep it accessible (belt holster, not buried in a pack). Effective range is 5–10 meters. Aim slightly downward. Spray a 2-second burst when the bear is within range. Bear spray is statistically more effective than firearms at stopping bear charges.

7. Mountain Lions / Big Cats

• Do not run. Running triggers a chase response.
• Face the animal. Make yourself look large (raise arms, open jacket wide).
• Shout. Throw rocks or sticks.
• Maintain eye contact. Back away slowly.
• If it attacks: fight back aggressively. Target the eyes and nose. Do not play dead.
• Mountain lion attacks on adults are rare. They're more common with children — keep kids close in mountain lion country.

8. Snakes

• Most snakes are not aggressive and will flee if given the chance.
• Watch where you step and put your hands. Most bites occur on feet, ankles, and hands.
• Step onto logs, not over them (a snake may be resting on the far side).
• Don't reach into holes, under rocks, or into thick brush without looking first.
• If bitten: see the First Aid guide — snake bites section.

9. Moose & Large Herbivores

Moose are actually more dangerous than bears statistically. They are unpredictable, especially cows with calves and bulls in rut (autumn).

Signs a moose is agitated:

• Ears laid back
• Hackles (hair on neck/shoulders) raised
• Licking its lips
• Lowering its head

If a moose charges:

• Run. (Unlike bears, running from moose is appropriate — they usually won't pursue far.)
• Get behind a tree, boulder, or vehicle.
• If knocked down, curl into a ball and protect your head. Don't get up until the moose has moved well away — they may attack again if you stand too soon.

10. Dangerous Insects

• Mosquitoes carry malaria, dengue, and other diseases in tropical/subtropical regions. Use repellent, wear long sleeves at dawn/dusk, sleep under a net if possible.
• Ticks carry Lyme disease, Rocky Mountain spotted fever, and other infections. Check your body thoroughly each evening. See First Aid guide for removal.
• Scorpions — shake out boots and clothing before putting them on in desert environments. Most stings are painful but not fatal (except for very small children and certain species).
• Spiders — most are harmless. Black widows and brown recluses (in the Americas) and funnel-webs (in Australia) are dangerous. Avoid reaching into dark crevices.

11. River Crossings

Moving water is far more powerful and dangerous than it looks.

• Never cross above rapids, waterfalls, or deep pools.
• Cross at the widest, shallowest point. More width means less depth and less current.
• Unbuckle your pack's waist and chest straps before crossing. If you fall, you need to be able to shed the pack instantly — it will drag you under.
• Use a walking stick or sturdy branch on the upstream side for stability. Face upstream and move sideways.
• If in a group: cross in a line, strongest person upstream. Lock arms or hold each other's pack straps.
• If swept away: immediately shed your pack. Roll onto your back, feet downstream (to fend off rocks). Angle toward the nearest bank using backstroke.