weather balloon 
noun
A balloon equipped with meteorological apparatus which is sent into the atmosphere to provide information about the weather.The launch team had noted what NASA describes as ‘marginal’ wind conditions during the countdown, and wanted to double-check the data against information from a final weather balloon....
- On arriving there Peter and Chris got out of the vans and sent up a weather balloon to watch the wind direction.
- The Port Elizabeth weather office said there wasn't a weather balloon in that area and no calls reporting UFOs had been received.
- notitia
- not just any ——
- Notkerian
- not know from nothing
- not know if one is coming or going
- not know one is born
- not know one's arse from one's elbow
- not know shit
- not know shit from Shinola
- not know someone from a bar of soap
- not know someone from Adam
- not know that
- not know the first thing about
- not know the meaning of the word
- not know what hit one
- not know what to do with oneself
- not know where (or which way) to look
- not know where to put oneself
- not know which way (or where) to turn
- not least
- not let the grass grow under one's feet
- not-life
- not likely!
- not like the look (or sound) of
- not-living