CHANCE OF FLARES: NOAA forecasters estimate a 50% chance of X-class solar flares and an 80% chance of M-class solar flares today. The source would be active sunspot AR1748, which is turning toward Earth. Solar flare alerts: text, voice.
ANOTHER X-FLARE ON MAY 15: When the week began, the sun hadn't unleashed an X-flare all year long. In only two days, sunspot AR1748 has produced four. The latest X-flare from this active sunspot occured on May 15th at 0152 UT. NASA's Solar Dynamics Observatory captured the extreme ultraviolet flash: Although the sunspot is not directly facing Earth, this flare might have produced a CME with an Earth-directed component.
We are waiting for coronagraph data from SOHO and the twin STEREO probes to check this possibility. Stay tuned for updates. In summary, AR1748 has produced an X1.7-class flare (0217 UT on May 13), an X2.8-class flare (1609 UT on May 13), an X3.2-class flare (0117 UT on May 14), and an X1-class flare (0152 on May 15). These are the strongest flares of the year, and they signal a significant increase in solar activity.