  Coronal holes (CHs) are the source of high-speed streams (HSSs) in the solar
wind, whose interaction with the slow solar wind creates corotating interaction
regions (CIRs) in the heliosphere. Whenever the CIRs hit the Earth, they can
cause geomagnetic storms. We develop a method to predict the strength of
CIR/HSS-driven geomagnetic storms directly from solar observations using the CH
areas and associated magnetic field polarity. First, we build a dataset
comprising the properties of CHs on the Sun, the associated HSSs, CIRs, and
orientation of the interplanetary magnetic field (IMF) at L1, and the strength
of the associated geomagnetic storms by the geomagnetic indices Dst and Kp.
Then, we predict the Dst and Kp indices using a Gaussian Process model, which
accounts for the annual variation of the orientation of Earth's magnetic field
axis. We demonstrate that the polarity of the IMF at L1 associated with CIRs is
preserved in around 83% of cases when compared to the polarity of their CH
sources. Testing our model over the period 2010-2020, we obtained a correlation
coefficient between the predicted and observed Dst index of R = 0.63/0.73, and
Kp index of R = 0.65/0.67, for HSSs having a polarity towards/away from the
Sun. These findings demonstrate the possibility of predicting CIR/HSS-driven
geomagnetic storms directly from solar observations and extending the
forecasting lead time up to several days, which is relevant for enhancing space
weather predictions.
