The Sun doesn't just shine. It erupts, throwing billion-ton clouds of magnetized plasma into space. Those clouds are coronal mass ejections, and this is today's real catalog of them.
A CME is matter. It takes one to three days to cross to Earth, and that travel time is the whole reason storms can be forecast. Its cousin the solar flare is light: here in eight minutes, no outrunning it.
And most CMEs miss us entirely, because the Sun fires in every direction and Earth is a small target. A wedge on the map hits Earth only if Earth sits inside it.
Tap any wedge on the map above. Then make the call a forecaster makes first: is this one aimed at Earth?
None of the structure above is visible from Earth. NASA fits a cone to the coronagraph images and publishes four numbers: launch time, speed, direction and half-width. The wedge is that cone, pushed outward through the solar wind by the drag model. Everything inside it stays a guess until the front reaches L1.