Weather Reading

The sky briefs you every morning whether you listen or not. This chapter teaches the cloud types, wind and pressure trends, and animal signs that telegraph coming weather — and the lightning safety rules for when the forecast arrives faster than you planned.

Cloud types — what each one signals

HIGH CLOUDS (above ~20,000 ft, ice crystals): CIRRUS — wispy 'mare's tail'; fair now, but if it thickens into cirrostratus, a warm front is coming. CIRROSTRATUS — a thin veil, often with a halo around the sun or moon: the classic 12–24-hour warning of deteriorating weather. CIRROCUMULUS — rippled 'mackerel sky': variable weather, warm front with rain possible.

MID CLOUDS (6,500–20,000 ft): ALTOCUMULUS — patchy bumpy rolls; on a warm humid day, altocumulus by late morning means scattered afternoon thunderstorms. Turreted altocumulus (castellanus) means instability aloft. ALTOSTRATUS — a uniform gray sheet with the sun a dim disc; lowering and darkening means widespread steady precipitation approaching.

LOW CLOUDS (below ~6,500 ft): STRATUS — a featureless gray blanket; drizzle, mist, poor visibility. STRATOCUMULUS — a lumpy rolling sheet; showery, often around fronts. NIMBOSTRATUS — the dark layered rain cloud; continuous steady rain or snow.

VERTICAL CLOUDS: CUMULUS — fair-weather puffs with flat bases; growing vertical extent means building instability. CUMULONIMBUS — the thunderstorm: anvil top, dark base, lightning, hail, violent wind. LENTICULAR — smooth lens-shaped clouds stacked over mountains: a standing wave with brutal winds aloft and rotor nearby. MAMMATUS — pouches under a storm's anvil: severe weather.

The forecast playbook: morning cirrus thickening to cirrostratus with a halo = change within 12–24 hours (shorten the travel day). Altocumulus late morning on a warm humid day = be below treeline by early afternoon. Altostratus lowering to gray = steady precipitation coming (choose high, drained ground; protect gear now). Towering cumulus with anvils plus distant thunder = get off ridges and water NOW.

• Learn ten cloud types the way you learn ten plants — they are a field guide to the sky.

Illustration: Cloud identification: cirrus, cirrostratus, altocumulus, cumulonimbus, and lenticular.

Wind shifts and pressure trends

The mountain storm pattern: a SUDDEN WIND REVERSAL or direction shift, plus gust increase, plus a sharp temperature drop — that is a storm front arriving, not passing weather. Barometric pressure is the trend line: FALLING pressure means deteriorating weather, RISING means improving, STEADY means no change — and a RAPID drop means a strong storm. A sudden calm after wind — 'the calm before' — often precedes squall lines. Lenticular clouds mean strong upper winds even on a calm-feeling day.

Plan around it: schedule summer mountain travel for mornings, and know your bail routes BEFORE afternoon convection fires.

• A cheap watch with a barometer is worth more than a forecast you cannot receive.

Insect and animal behavior — supporting clues only

Swallows and other birds flying LOW means falling pressure is pushing insects down — rain likely. Livestock bunching, restless dogs, vocal frogs: supporting clues. Bees and mosquitoes congregating can also flag nearby moisture and water sources.

Treat ALL of these as folk indicators — supporting clues, never a forecast. They corroborate what the clouds and the barometer say; they do not replace them.

• When the birds, the clouds, and the pressure all agree, believe them.

Lightning safety — plan first, crouch last

THE 30-30 RULE: if 30 seconds or less pass between the lightning flash and the thunder, take shelter IMMEDIATELY (sound travels about 5 seconds per mile — 'flash-to-bang' math). Then wait 30 MINUTES after the last thunder before resuming outdoor activity. Most strikes happen before and after the storm's peak, not during it.

NO PLACE OUTSIDE IS SAFE. The safe options: a substantial enclosed building or a hard-topped metal vehicle. AVOID: tall isolated objects (trees, poles), open fields and ridge tops, bodies of water, metal fences and bleachers — and note that picnic shelters and sheds are NOT safe.

LAST RESORT ONLY: crouch low like a baseball catcher, feet close together, hands over your ears — and NEVER lie flat, because ground current spreads 100+ feet. Spread group members out: clustered people get hit together by splashover. WARNING SIGNS of an imminent strike: hair standing on end, skin tingling, buzzing/clicking/hissing sounds, metal objects glowing blue-white — assume the crouch position immediately.

NOTE — conflicting expert advice, flagged honestly: the crouch is still widely taught, but some emergency-management advisories note that experts no longer emphasize it because there is little evidence it helps enough to rely on. The primary expert advice is to AVOID BEING OUTSIDE IN A STORM AT ALL — plan around forecasts. (Seeking low ground for lightning conflicts with flash-flood risk — in a low area, stay alert for rising water.)

If someone is struck: they do NOT retain a charge — it is safe to touch them. Call 911; start CPR if heart or breathing have stopped — it can save a life. Indoors during a storm: stay away from plumbing, electrical appliances, landline phones, windows, and running tap water.

• Check the forecast every morning the way you check your water — it is that basic.

Illustration: Lightning safety: the crouch position in the open, away from lone trees, water, and ridgetops.