You can find a light curve of the comet from Japanese observations here . At present the comet is in Virgo and a morning object only 45 degrees from the Sun although it attains a reasonable altitude in the sky before dawn. It may brighten further still. Over the next few weeks the comet will maintain an almost constant position relative to the Earth in its orbit and thus will stay at an almost constant distance from the Sun in the sky and at an almost constant distance from the Earth. Any further brightening will indicate that the outburst is still continuing.
Nobody actually knows what causes outbursts in comets.
There are many theories. Certainly, in some cases they are due to a fragmentation of the nucleus. In others all we see is that a large dust and gas cloud is suddenly expelled for no readily apparent reason. This may be due to small eruptions, not unlike volcanic activity, on the surface of the nucleus, where a small pocket of volatile ice suddenly sublimes and breaks through the crust on the nucleus leading to a small explosion of gas that blows dust and ice out into space. Many eruptions though take place at great distance from the Sun where such violent sublimation is not expected to occur.