Many of the resources listed on this tool reference the NOAA Space Weather Scales and other indices.

The Space Weather Scales of the National Oceanic and Atmospheric Administration were developed by NOAA's SWPC to improve understanding of space weather events among technical operators and the general public alike.

The scales serve a purpose similar to that of Hurricane Categories 1-5, correlating space weather disturbances with their likely effects on technological systems.

To many who see space weather as an obscure field, the NOAA Space Weather Scales convey useful information and perhaps pique new scientific interest.

NOAA Space Weather Scales may be accessed through the SWPC site or through the following direct link: http://www.swpc.noaa.gov/noaa-scales-explanation.

There are three scales, each with 5 levels of severity:

Space Weather Scale	Extreme	Severe	Strong	Moderate	Minor
Geomagnetic Storms: disturbances in the geomagnetic field caused by solar wind energy.	G5	G4	G3	G2	G1
Solar Radiation Storms: elevated levels of solar energetic protons.	S5	S4	S3	S2	S1
Radio Blackouts: disturbances of the ionosphere caused by X-ray emissions from the Sun.	R5	R4	R3	R2	R1

Each scale provides lists of possible effects seen with each category of activity, the physical measure that determines the category of an event, and a climatological assessment that explains how often we can expect to see events of each magnitude during an 11 year solar cycle.