The weather has turned cloudy and cool which has put the experiment on hold.

A couple of recent nights showed the effect of the dew point.  The first night the temp was 35 and the box was 32 and covered with heavy dew.  The next tight the temp was 36 and the box was 20 but no ice.  The bottom of the box was covered with frozen dew.  The third night the temp was 34 and the box was 17 with the water frozen hard and the saline mix slushy.  The box was dry.

It is looking like a dT of 17 degrees is attainable under the right conditions which would allow ice formation at 47-49 degrees.  Hope to resume the experiment in January.