Cooling Pacific Ocean conditions that follow an El Nino and known to hinder winter storms from dousing California have weakened enough that forecasters “La Nina watch” Thursday. In wake of one the strongest El Ninos ever recorded, Pacific Ocean water temperatures are gradually returning to normal and there is only a 40 percent chance of a strong La Nina developing this winter, climate scientists with the National Oceanic and Atmospheric Administration said in a monthly update.The update sparks optimism that El Nino’s drier sibling won’t materialize over drought-riddled California, despite NOAA scientists in May giving La Nina a 75 percent chance of developing.