Space Weather Message Code: SUMSUD Serial Number: 221 Issue Time: 2017 Jul 01 1735 UTC SUMMARY: Geomagnetic Sudden Impulse Observed: 2017 Jul 01 1712 UTC Deviation: 20 nT Station: CMO NOAA Space Weather Scale descriptions can be found at www.swpc.noaa.gov/noaa-scales-explanation ---- Explanation -----
All SWPC Space Weather Alert Messages for geomagnetic phenomena are based primarily on NOAA's real-time estimate of the planetary Kp index. Planetary K-index values of 5 through 9 correspond to the NOAA Geomagnetic Storm (G-Scale) for categories G1 through G5.
| WARNING: Geomagnetic Sudden Impulse expected |
| SUMMARY: Geomagnetic Sudden Impulse |
A Geomagnetic Sudden Impulse WARNING is issued based primarily on solar wind data available from the ACE satellite. These warnings are generally for short lead-time (10-60 minutes), high confidence indication of an expected Geomagnetic Sudden Impulse, and possible onset of subsequent geomagnetic storming. A Geomagnetic Sudden Impulse SUMMARY is issued upon its observation, and will generally be based on data from the primary Boulder USGS magnetometer, but may be based on a specified alternate magnetometer station if Boulder data is not available.