You can quickly get to the "GOES X-ray Flux (5 minute data)" from the Space Weather Resource page. The RED line indicates the level of solar activity that will affect Earth.
X-rays are continually emitted from the Sun. Detecting significant increases in the intensity of those x-rays can provide an early warning of a solar storm. Two GOES satellites record solar x-ray emission, GOES 10 and GOES 12. However, GOES 12 x-ray data is a good indicator that a solar storm is likely coming toward Earth and should be used to verify the student data from the Radio JOVE. When observing the data from the GOES 5 Min X-ray Plot, the red plot from GOES 12 is the one we want use.
Scientists have developed a simple rating system for this solar x-ray activity. They have created five levels; A, B, C, M, and X.
So this makes an X event 10,000 times stronger than A. In addition, each level can be further divided from 1.0 to 9.9. This means you could have a C2.3 event, or a B7.9 or an M6.5 . Even though X is the highest level, the numbers don't stop at X9.9. On October 28, 2003 there was an X17.2 flare followed several days later by an approximately X28 flare (actually it was so strong it was hard to measure).These were the biggest flares ever measured. Remember is usually takes 3 days for the solar storm to reach Earth. However, the storm in 2003 took only 19 hours!
Using the solar x-ray activity scale (A,B,C,M, and X) along the right side of the graph, you can not only determine the power of the solar storm but also the potential for Auroral sightings!
The sample image below show the GOES x-ray plots for solar storms on May 27 and 28, 2003. It also shows that normal solar activity was in the B range. There were 6 flares in the high C or low M range May 26 and 27. Then late on May 27 and shortly later on May 28 two X-class flares erupted. Images from SOHO showed that both sent CMEs (coronal mass ejections) toward Earth. These CMEs disturbed the Earth's magnetosphere significantly and produced auroras as far south as Virginia. In general you want to be alert for M-class and X-class flares.
THIS IMAGE IS NOT LIVE DATA
The above tutorials compliment the downloadable Flip Charts and Data Sheets.