NOAA Issues Rare , Warning Following Powerful , Solar Event.<br />CBS reports that a severe G4 geomagnetic storm <br />headed towards Earth has triggered a rare warning <br />from NOAA officials for the first time in two decades.<br />The warning comes following days of solar activity <br />that sent several waves of plasma in Earth's <br />direction along with powerful magnetic fields.<br />G4 storms are the second-strongest <br />type of geomagnetic storms and can <br />cause widespread voltage problems. .<br />NOAA warns that they can also cause some <br />protective assets to "trip out key assets from the grid," <br />as well as cause orientation problems for spacecraft. .<br />If geomagnetic storms <br />were hurricanes, 'severe' <br />would be category 4. , Spaceweather.com, via CBS.<br />The powerful G4 storm could also cause <br />northern lights, or aurora borealis, to be seen <br />in northern California and as far south as Alabama.<br />In a May 9 press release, NOAA said that the solar <br />event began on May 8, when a group of sunspots <br />generated "several moderate to strong solar flares.".<br />According to NASA, solar flares are explosions of <br />radiation which are considered the strongest <br />explosive events in the solar system.<br />NOAA noted that the area, which <br />produced the recent flares, is roughly <br />16 times the diameter of the Earth.<br />The sunspots known as AR3664 measures about 124,000 <br />miles across, and Space.com notes that it is one of the, "largest and most active <br />sunspots seen this solar cycle." .<br />According to NOAA, the geomagnetic storm <br />is expected to hit Earth as early as midday <br />on May 10 and continue through May 12
