NOAA 2000-613
Contact: Barbara McGehan


A large complex sunspot group has produced one of the largest solar flares and associated radiation storms seen in recent years. The solar flare occurred on the sun at about 6:24 a.m. EDT on July 14, according to forecasters at NOAA's Space Environment Center in Boulder, Colo. Solar flares are classified by their peak x-ray intensity and this event was classified as an X-5.9, on a scale of 20, which is considered to be a strong event.

A large Coronal Mass Ejection (CME) associated with the flare, ejected billions of tons of plasma and charged particles into space, which is now heading towards Earth at a speed of three million miles per hour. The mass ejection is expected to impact the Earth's magnetic field and result in a geomagnetic storm on Saturday afternoon that may last until Monday. The storm is expected to reach strong to severe levels (G-3 to G-4 on the NOAA Space Weather Scales), which can adversely affect satellite operations and power grids.

The solar flare has already caused some effects on Earth including strong radio blackouts at the R-3 level on the sunlit side of the Earth. A solar radiation storm is also in progress (S-3 on the NOAA Space Weather Scales) which is categorized as strong. This is the largest solar radiation storm since October of 1989. Solar radiation storms can reach Earth very quickly and can cause effects such as low-level radiation for commercial jet crews flying at high latitudes and single event upsets for satellites.

In addition, there is a good chance of seeing the Aurora Borealis Saturday night through Sunday morning in the mid-latitudes and possibly lower. Cities such as Washington, D.C., Seattle, New York, and Denver (with the possibility of other cities located in the southern U.S.) may be able to observe this phenomena.

NASA's ACE satellite, in orbit between the Earth and Sun at a distance of one million miles from Earth, will detect any geomagnetic storms approaching Earth and provide NOAA forecasters with a warning about one hour before they reach Earth's magnetic field.

For updates consult NOAA's Space Environment Center Web site. Click on "Space Weather Now" and then click on "Last Space Weather Bulletin."