According to forecasts, the geomagnetic storm was supposed to begin tomorrow, July 23, after the outbreak that occurred on the 20th, but at the moment a geomagnetic storm is being recorded on Earth reaching values of Kr4.
Today, there was a small flare on the Sun and perhaps this storm is associated with it or the forecasters from NASA were mistaken and the plasma cloud came earlier than expected.
A thread of magnetism near sunspot AR2846 erupted on July 20, triggering a Class B solar flare and ejecting a plasma cloud into space. Usually the location of the explosion site excludes impact on the Earth. However, the clouds of the explosion plasma scattered to the sides.
NOAA simulations assumed the edge of the cloud would hit the Earth's magnetic field on July 23 or 24, triggering geomagnetic storms, if so, today's geomagnetic storm will continue upon the arrival of this plasma cloud.