The first wave of snow arrives in Mammoth Monday morning, Oct. 25 following 30 straight hours of rain from a record-breaking atmospheric river storm. Forecasts call for snow instead of rain for the rest of the day before the big storm exits the Eastern Sierra later tonight or tomorrow. The amount of snow Mammoth Mountain will receive before the storm exits is still undetermined; it could be anywhere between one and five feet depending on how long the storm settles over the Central Sierra today. In the meantime, only minor flooding in the Town of Mammoth and other areas of the county, along with the Walker River cresting just below flood stage, are good news and the huge amount of new precipitation in the drought stricken area even better news.