Noise storms are associated with active regions. Active regions are regions in the solar atmosphere with high concentrations of magnetic fields, and they include a sunspot at their base in the photosphere except in cases where the magnetic fields are fairly weak. The association with active regions has been known for decades, but the conditions required to produce noise storms are still mysterious. Not all active regions that produce other forms of activity such as flares generate noise storms, and unlike other types of solar radio bursts, it is often difficult to identify non-radio signatures of Type I bursts.