🌐 Understanding the KP Index

The KP index is your primary tool for Aurora forecasting. It measures global geomagnetic activity on a scale of 0-9, updated every 3 hours by NOAA.

KP Index Guide for Iceland

KP 0-2: No Aurora visible from Iceland
KP 3-4: Aurora often visible in rural Iceland, minimal activity
KP 5-6: Strong Aurora, visible near cities including Reykjavík
KP 7-9: Extreme storm, Aurora visible everywhere

🧲 The Critical Bz Component

The Bz component of the Interplanetary Magnetic Field (IMF) is the most important real-time indicator for Aurora activity.

Understanding Bz Values

  • Bz Positive (+): Points north, aligns with Earth's field → No Aurora
  • Bz Negative (-): Points south, can reconnect with Earth's field → Aurora possible
  • Stronger negative values: Generally increase Aurora probability
  • Duration matters: Sustained negative Bz more important than brief dips
  • For strong auroras: Look for Bz values of -10 nT or stronger, sustained for 30+ minutes

🕐 Timing Your Aurora Hunt

Solar wind data from the L1 Lagrange point (DSCOVR satellite) reaches Earth in 45-60 minutes. When you see favorable Bz values, you have about an hour to get ready!

💨 Solar Wind Parameters

Key Solar Wind Measurements

Solar Wind Speed

  • 300-400 km/s: Slow solar wind, minimal Aurora enhancement
  • 400-500 km/s: Moderate speed, normal Aurora activity
  • 500-700 km/s: High speed, enhanced Aurora intensity
  • 700+ km/s: Very high speed, potential for strong storms

Solar Wind Density

  • 1-5 protons/cm³: Low density
  • 5-15 protons/cm³: Normal density
  • 15+ protons/cm³: High density, enhances magnetic effects

🌩️ Space Weather Events

Coronal Mass Ejections (CME)

What is a CME?

A CME is a massive burst of solar plasma and magnetic field released from the Sun's corona. CMEs can cause multi-day Aurora storms when they reach Earth.

Travel Time: 1-3 days from Sun to Earth
Duration: Aurora activity can last 12-48 hours

High-Speed Solar Wind Streams

These originate from coronal holes on the Sun and create recurring Aurora activity patterns, often repeating every 27 days (one solar rotation).

📱 Essential Forecasting Tools

Real-time Data Sources

⚠️ Forecast Reliability

  • 3-hour forecasts: Most reliable for planning
  • 24-hour forecasts: Good for travel planning
  • 3-day forecasts: General trends only
  • Real-time data: Most accurate for immediate decisions

🌤️ Weather Integration

Perfect space weather is useless if clouds block the view. Always check cloud forecasts alongside Aurora predictions.

Iceland Weather Resources

  • Vedur.is: Official Iceland weather service
  • Windy.com: Detailed cloud cover animations
  • Yr.no: Norwegian weather service (very accurate for Iceland)
  • Mountain-forecast.com: High-altitude weather