G1 (Minor) Geomagnetic Storm in Progress - New Sunspot Facing Earth
UPDATE: Coronal Hole stream is now geoeffective. The minor (G1) geomagnetic storm threshold was reached at 14:58 UTC (June 16).
ALERT: Geomagnetic K-index of 5 Threshold Reached: 2017 Jun 16 1458 UTC Synoptic Period: 1200-1500 UTC Active Warning: Yes NOAA Scale: G1 - Minor
A high speed solar wind stream flowing from a pair of relatively small coronal holes is expected to reach Earth within the next 24 hours. A minor (G1) geomagnetic storm watch is now in effect. Sky watchers at higher latitudes should be alert for visible aurora should local light and weather conditions allow.
A G1 (Minor) geomagnetic storm warning has been issued from 08:43 UTC until 15:00 UTC on 16 June 2017 due to coronal hole high speed stream activity.
GEOMAGNETIC STORM WATCH: NOAA forecasters say there is a 20% chance of G1-class geomagnetic storms today, June 16th, when a fast-moving stream of solar wind is expected to buffet Earth's magnetic field. The gaseous stream is flowing from a large hole in the sun's atmosphere. High-latitude sky watchers should be alert for auroras, especially in the southern hemisphere where deepening autumn darkness favors visibility.
Solar activity was very low. The largest flare of the period was a B2/Sf observed at 15/1700 UTC from Region 2663 (N14W07, Dso/beta-gamma). Slight growth was observed in the leader and trailing spots of Region 2663 while slight decay was observed within its intermediate spots. No Earth-directed CMEs were observed in available coronagraph imagery.
New sunspot AR2663 has a 'beta-gamma' magnetic field that harbors energy for M-class solar flares.
Clips, images credit: NOAA/SWPC, NASA/SDO
