To date, there are two spots on the Sun, which pose a threat to strong flares: AR2644 and AR2645. Both of them have unstable delta-class magnetic fields that cover energy for M- and X-class flares. These spots are indicated in this photo of the Sun on April 4, made by the NASA Observatory of Solar Dynamics.
Sun freckle AR2644 is of special interest. Since the beginning of the month, it has produced more than a half-dozen solar flares of the M-class, which has caused many short-wave radio cut-offs on Earth. In addition, this spot is magnetically well connected to the Earth. Magnetic fields on the solar western extremity from the spot are almost directly directed to our planet. If AR2644 explodes today, vigorous particles accelerated by the explosion can be directed to Earth, creating a radiation storm over the atmosphere of our planet.
Forecasters NOAA estimate in 70% chance of M-class outbreaks and 25% probability of X-flares on April 4.