
A G3 (Strong) geomagnetic storm watch is in effect for 31 Dec, with a G1 (Minor) watch for 1 Jan. These are in anticipation of a pair of Earth-directed coronal mass ejections (CME). The G1 Watch for 1 Jan is being considered for upgrade to a G2 Watch. SWPC forecasters have a fair level of confidence in some measure of Earth effectual components and general timing windows of these two particular CMEs, however, as is usual with these events, intensity is less certain. We will not know the true potential of geomagnetic disturbance levels of response until the CME(s) arrive 1 million miles from Earth (when they will be about 30-60 minutes from reaching our planet) and their structure and intensity can be measured by our solar wind observatories - NOAA DSCOVR and NASA ACE spacecraft. Also, neither CME is expected to be a direct hit, which also makes forecast of intensity more difficult. Continue to follow our webpage for the latest forecasts and information.