Solar wind parameters measured at ACE were predominately indicative of
background solar wind conditions. The phi angle indicated the influence
of a positive (away) orientation through most of the period. At
approximately 01/0930 UTC the phi angle switched to a negative (towards)
orientation and wind speed began a steady climb from approximately 375
km/s to a high of 447 km/s at 01/1136 UTC. The total interplanetary
magnetic field reached a peak value during this same timeframe of 16.2
nT while the Bz component subsequently dropped as low as -12.9 nT.
Analysis would indicate that we are beginning to see the effects of a
negative-polarity, coronal hole high-speed stream (CH HSS).