Definition: Space weather is the condition of the space environment extending from the surface of Earth to the Sun. The Sun’s energy output is always varying; consequently space weather is constantly changing.

Data: A space weather forecast begins with a thorough analysis of the Sun and the space environment. Forecasters use many different types of solar images and models to analyze active solar regions, localized areas that typically contain enhanced magnetic fields and sunspots.

Solar Cycle: The number of sunspots on the surface of the Sun increases and decreases in solar cycles of approximately 11 years.

Driver: The most dramatic drivers of space weather are solar flares, Coronal Mass Ejections, and solar particle events.

Events: These drivers cause the three major categories of space weather storms: Radio Blackouts, Geomagnetic Storms, and Solar Radiation Storms. Through the resulting enhancements in x-rays, geomagnetic activity, and energetic particle radiation, a wide variety of activities are impacted.

Impacts: The impacted systems and activities include: electric power systems, navigation systems, aviation, human space exploration, satellite operations, surveying, and radio communication. To mitigate the impacts of space weather, forecasters use space-based data, ground-based data, and computer models to forecast space weather and to alert users when conditions become hazardous.