A G2 (Moderate) geomagnetic storm warning has been issued in response to some enhanced solar wind ahead of the next coronal hole high speed stream (this enhancement is well-reflected in the top panel of this ACE data plot near the start of the day on Jan. 21st). Coronal holes can create an enhanced structure ahead of their arrival, called a Co-rotating Interaction Region (CIR) in scientific terms, and these features can drive low to mid-level geomagnetic storming. No periods of storming have been observed so far but storming in the near term is possible.
***UPDATE: Conditions no longer warrant a G2 (Moderate) geomagnetic storm warning. Solar wind conditions are expected to remain enhanced, but are expected to remain below the G1-Minor storm threshold for the time being. Stay tuned for updates.***