A typhoon is a tropical cyclone that forms in the Western Pacific Ocean. These powerful rotating storm systems develop over warm ocean waters (above 26.5°C / 80°F) and are characterized by:

• Organized thunderstorm clusters rotating around a low-pressure center
• Sustained winds of at least 74 mph (119 km/h, 33 m/s)
• Counter-clockwise rotation in the Northern Hemisphere
• Heavy rainfall, storm surge, and powerful ocean swells

Formation Process: Typhoons begin as tropical disturbances, intensifying through a feedback loop where warm, moist air rises and condenses, releasing heat energy that fuels further development. The Coriolis effect from Earth's rotation causes the system to spin.

The same phenomenon is called a "hurricane" in the Atlantic / Eastern Pacific and a "cyclone" in the Indian Ocean. Only the regional name differs.

The Western Pacific has the most active typhoon basin in the world, with typhoons possible year-round and an average of 16 per year. However, activity varies by season:

• Peak Season (July–October): Most frequent and intense typhoons. August and September see the highest activity.
• Secondary Peak (May–June): Early season storms, often forming further south near the Philippines.
• Off-Season (November–April): Reduced activity, but occasional strong systems can still develop, particularly in the southern basin.

Climate Influences: El Niño and La Niña cycles affect typhoon tracks and intensity. El Niño years tend to shift storm formation further east, while La Niña can bring more systems closer to Asia's coastlines. Long-term warming trends may also influence storm intensity and rainfall.

Taiwan's position in the Western Pacific puts it directly in the path of many typhoon tracks. Common patterns include:

• Westward Track: Forms east of the Philippines, moves west-northwest, crossing Taiwan or passing just south. Peak season pattern.
• Recurving Track: Approaches from the south or southeast, curves northeast past Taiwan toward Japan. More common in late season (Sept–Oct).
• Northern Track: Forms further east, passes north of Taiwan through the Ryukyu Islands. Still generates swell for northern coasts.
• Direct Hit: Crosses Taiwan's main island, bringing extreme winds and rainfall to both coasts. Less common but highest impact.

Steering Currents: The subtropical ridge and mid-latitude westerlies influence track direction. Monitoring pressure patterns helps predict whether a typhoon will curve away or make landfall.

Typhoons are classified by sustained wind speeds, which determine their intensity and potential impact. Understanding these categories helps assess threat levels and prepare accordingly:

International Classifications

• Tropical Depression: Winds below 39 mph (63 km/h, 17 m/s). Organized circulation with potential to strengthen.
• Tropical Storm: Winds 39-73 mph (63-118 km/h, 17-33 m/s). Named system with defined circulation and rain bands.
• Typhoon (Cat 1-2): Winds 74-110 mph (119-177 km/h, 33-49 m/s). Dangerous sustained winds, significant coastal impacts.
• Typhoon (Cat 3-4): Winds 111-156 mph (178-251 km/h, 50-70 m/s). Major to extreme typhoon with devastating damage potential.
• Super Typhoon (Cat 5): Winds 157+ mph (252+ km/h, 70+ m/s). Catastrophic damage, extreme storm surge, life-threatening conditions.

CWB (Taiwan) Classifications

• Mild Typhoon (輕度颱風): Winds 39-73 mph (62-117 km/h, 17-33 m/s). Moderate threat level.
• Moderate Typhoon (中度颱風): Winds 73-114 mph (118-183 km/h, 33-51 m/s). High threat level requiring preparation.
• Severe Typhoon (強烈颱風): Winds 114+ mph (184+ km/h, 51+ m/s). Extreme threat requiring evacuation considerations.

For Surfers: Even tropical storms and weaker typhoons generate powerful swells. Monitor intensity forecasts to time sessions—prime surfing windows often occur 24-48 hours before arrival when swell builds but winds remain manageable.

Typhoons generate powerful, long-period swells that can transform Taiwan's surf breaks. Understanding regional impacts helps maximize sessions safely:

East Coast (Yilan, Hualien, Taitung)

• Primary Swell Window: Open to E, SE, and NE swells. First to receive typhoon energy.
• Typical Size: Can reach 8-15+ ft faces with periods of 12-16s during peak swell events.
• Timing: Swell arrives 24-48 hours before typhoon passage, peaks during closest approach, tapers 12-24 hours after.
• Considerations: Onshore winds common during typhoon passage. Best windows often before arrival or after departure with offshore winds (ideal conditions).

Northeast Coast (Fulong, Green Bay, Jinshan)

• Swell Window: NE to E exposure. Benefits from typhoons tracking north or recurving.
• Bathymetry: Reef and point breaks focus energy. Can handle larger swells with better shape than beach breaks.
• Wind: Offshore SW winds during post-typhoon high pressure can create firing conditions.

South Coast (Nanwan, Jialeshui)

• Swell Window: S to SE swells. Better for typhoons passing south of Taiwan or approaching from the southwest.
• Shadowing: Protected from northerly swells by the main island.
• Season: Summer typhoons (July-Sept) more likely to send surfable swells here.

West Coast (Qijin, Yuguangdao, Songbai Harbor)

• Minimal swell from typhoons due to Taiwan Strait shadowing. Primarily wind-driven waves during typhoon passage.

Swell Period & Size: Longer periods (13s+) indicate groundswell that wraps into more exposed breaks. Shorter periods (8-11s) suggest wind swell or fetch-limited conditions. Always check both size AND period for quality assessment.

Interpreting typhoon forecast data helps surfers time sessions and assess conditions. Key elements to monitor:

Wind Field Analysis

• Wind Speed Contours: Tighter spacing = stronger winds. Look for asymmetric patterns—swell generation strongest in the right-front quadrant (Northern Hemisphere).
• Fetch Length & Duration: Long fetch aligned toward your coast + sustained winds = better swell. Check wind direction arrows for consistency.
• Wind vs. Swell Direction: Winds blow from high to low pressure (clockwise around typhoon). Swell radiates outward but refracts based on bathymetry.

Pressure Systems

• Central Pressure: Lower pressure = more intense typhoon. Sub-950 hPa systems are major typhoons.
• Isobars (Pressure Lines): Closer spacing = stronger pressure gradient = higher winds.
• High Pressure Influence: Post-typhoon high pressure brings offshore winds to Taiwan—ideal for clean surf.

Track Cones & Timing

• Forecast Cone: Shows probable track area, not exact path. Wider cone = more uncertainty.
• Lead Time: Swell arrives before the storm. Use time markers on the track to estimate swell arrival windows.
• Model Consensus: Compare multiple models (GFS, ECMWF, JTWC). Clustered forecasts = higher confidence.

For Surfers: Focus on 24-72 hour windows when typhoon is 500-1000 km (300-600 miles) offshore—far enough for manageable local winds but close enough for strong swell. Avoid surfing during direct typhoon passage due to extreme winds, currents, and debris. Also be aware of the men and women in orange suits.

Typhoon swells bring exceptional surf but also serious hazards. Prioritize safety and respect local protocols:

Hazards to Avoid

• Shorebreak: Large swells dump directly on shore, causing neck/spinal injuries. Never turn your back on the ocean.
• Rip Currents: Exponentially stronger during big swells. If caught, paddle parallel to shore, don't fight the current.
• Debris: Typhoons dislodge trees, trash, and sharp objects. Check lineup for floating hazards before paddling out.
• Coastal Closures: Respect local authorities' beach closures and warnings. Fines and rescue costs apply for violations.
• Lightning: Outer typhoon bands bring thunderstorms. Exit water immediately if lightning is within 10 km.

Lineup Etiquette During Swell Events

• Know Your Limits: Typhoon swells are not the time to push beyond your skill level, and beginners should never surf them!
• Wait Your Turn: Peak crowds during swell events. Respect priority, don't snake waves or drop in.
• Communicate: Call off waves if you can't make them. Avoid collisions by staying visible and predictable.
• Help Others: Keep an eye on struggling surfers. Be ready to assist in emergencies.
• Leave No Trace: Take your trash when you leave the beach. Typhoons already bring enough debris; don't add to it.

When NOT to Surf

• During typhoon passage and sustained winds 25+ mph (40+ km/h, 11+ m/s), heavy rain and/or lightning
• Official warnings or closures in effect
• Alone with no backup or communication. Don't surf alone during a typhoon - it's not worth the risk.
• Conditions beyond your ability (honestly assess size, current, and wind)
• Poor visibility (fog, heavy rain, dusk/dawn during swell peaks)

⚠️ Remember: No wave is worth your life. Typhoon swells will come again. Make conservative decisions, surf with experienced buddies, and always have an exit strategy.

Proper equipment and preparation are essential for safely surfing typhoon-generated swells:

Board Selection

• Bigger Swells (8+ ft): Step up to a gun or semi-gun (7'0"-9'0"+ depending on wave size). More length = better paddling, stability, and wave catching in critical drops.
• Moderate Swells (4-7 ft): Standard shortboard or fish works. Add volume if conditions are wind-affected or you need more paddle power.
• Reef Breaks: Consider extra rocker and narrower tail for steep drops. Avoid soft-tops or fragile boards.

Essential Safety Gear

• Leash: Use a thicker, comp/big-wave leash (7mm+) for swells over 6 ft. Check swivels and rail saver for wear before each session.
• Helmet: Recommended for reef breaks. Protects against board hits and shallow impacts.
• Booties: Sharp coral, rocks, and debris are prevalent post-typhoon. Reef booties provide grip and protection.
• Rashguard/Wetsuit: Even in warm water, long sessions drain energy. Layer appropriately for temperature and abrasion protection.

Fin Setup

• Thruster (3-fin): Typically best all-around for control and maneuverability in varied conditions.
• Quad: More drive and speed in larger, hollower waves. Less directional control on steep drops.
• Single/2+1: Suitable for bigger boards and point breaks. Smooth, drawn-out turns.
• Fin Size: Typically the bigger the waves the smaller the fins you should use.

Pre-Session Checklist

• Check Central Weather Administration (CWA), local warnings, and coastal advisories
• Inspect board for dings (repair before session to avoid waterlogging)
• Test leash attachment and swivels
• Assess current, wind, and lineup from shore for 10+ minutes (you can do it while you stretch)
• Identify exit points and hazards (rocks, rips, shallow sections)
• Bring water, sunscreen, and first-aid kit to beach
• Tell someone your surf plan and expected return time

Post-Session Maintenance

• Rinse board and gear with fresh water immediately (saltwater + debris accelerates wear)
• Check for new dings; repair promptly to prevent water damage
• Dry leash and wetsuit thoroughly to avoid mold
• Inspect fins for cracks or looseness
• Clean wax buildup and reapply as needed

💡 Pro Tip: Keep a dedicated typhoon swell kit ready: backup leash, helmet, booties, first aid, and high-visibility rashguard. When forecasts show a swell window, you'll be prepared to go without scrambling for gear.