Cirrus clouds are the bane of an observer's existence, because these high ice clouds can cover over the sky, even when you observe from the top of a mountain as high as Mauna Kea. There's nothing you can do about them, but try and wait them out. Tonight, as you can see in the satellite image, we are riding the edge of a giant mass of cirrus to the south of us. Right now the sky is clear, but we saw our data getting scattered by thin wisps an hour ago. It could easily come back soon. To make matters worse, the even thicker set of cirrus to the north is slowly, day by day, forcing its way towards us and there are rumours of a storm coming. Storms are bad, because they cause hot air to rise much higher than is normal, dragging the water laden clouds with them. If they reach us, then the telescope has to close, in case water starts to condense on the telescope mirror.
So we sit, gripped by satellite imagery, high intensity all-sky cameras and even looking out at the night sky with night-vision goggles, hoping to understand what the weather holds for us.