Current meteorological conditions at the AAT.
The current weather (history here) at the AAT is:
Local date of report : 2024/11/21 Local time of report : 16:26:00 Outside air temperature : 20.5°C Dome air temperature : 13.8°C Outside humidity : 31.7% Outside dewpoint : 3.1°C Sky-Ambient : -26.3°C ± 1.0 SQM sky brightness : 0.00 mag/sq.arcsec Average wind speed : 7. km/h Maximum wind gust : 12. km/h Average wind direction : 49.° (NE) Barometric pressure : 667.4 mm Hg (and steady) The dome is : CLOSED The rain alarm says : No rain The Boltwood rain alarm says : No rain The Boltwood wetness meter says : Dry Rain since 9am : 0.0 mm
24-Hour plot of meteorological conditions.
Below is a plot showing the last 24 hours of meteorological conditions at the AAT. The plots show the barometric pressure, the wind speed and direction, and various temperatures.
yellow: outside air temperature cyan: outside dewpoint magenta: dome air temperature green: mirror temperature
Boltwood sensor plots
The Sky-Ambient temperature (effecively cloudiness - the lower the temperature and the steadier the plot the less cloud there is) plot for the last 24 hours. The Boltwood sensor also has separate rain and wetness sensors which appear along the bottom of the plot; the thickness of each point indicates the relative strength of the rain ( red ) or moisture ( orange ). If it's wet or raining, the Sky-Ambient temperature is locked at the last value.
SQM plots (Sky brightness)
We have a Unihedron Sky Quality Meter (SQM-LR - serial port interface) mounted near the AAT. It points slightly south of the zenith and records data during the night once per minute.
4-day plot of meteorological conditions.
And here is a plot showing the last 4 days of meteorological conditions at the AAT.
yellow: outside air temperature cyan: outside dewpoint magenta: dome air temperature green: mirror temperature
Details
Two MetPak Pro weather stations gather the data every 4 seconds from sensors in the dome, and from a station 200 metres north of the dome. Wind sensors are on the east edge of The Lodge about 100m north west of the dome, and are influenced by buildings and trees. These data are gathered and collated by a small computer located in the AAT control room and are plotted here as 1 minute averages.
The wind graph at upper right shows the wind direction in green with its scale on the right of the graph. The light blue is the average speed for the minute while the darker purple is the maximum gust in that period.
The bottom graph shows temperatures of the outside air (in yellow ); the outside dewpoint ( cyan ); the inside dome air ( magenta ); and the mirror temperature (strictly the air a few millimetres above the mirror, in green ).
A green bar across the top of the plot shows when the dome is open.
Any red along the bottom line shows that the rain sensor believes that it is raining.
The 4-day plot marks midnight of each local day with a vertical line.
Note that the times are local and do not take account of daylight saving.
We also have a Boltwood cloud sensor which yields the Sky-Ambient temperature reading detailed above. Temperatures below about -25°C should mean that the sky is clear (although high, cold cirrus cloud doesn't show up very well) while warmer temperatures mean progressively more and thicker cloud. It also has a rain and wetness sensor, both of which are also reported at the top of this page and provide a useful backup to our main rain alarm.
Like many non-critical automatic systems, there may be occasional glitches in this data. Please don't be alarmed if it isn't perfect.
These plots are generated by a FORTRAN program calling PGPLOT subroutines.
Links to relevant weather resources
There are many weather servers in web-space, I've listed just a few here that have relevant maps.
Australian Bureau of Meteorology - latest IR |
AAT all-sky camera |
|
AAT new all-sky camera, just before being struck by lightning |
Australian:
- CSIRO - Australia Telescope National Facility - Mopra - SkyCam,
- Australian Bureau of Meteorology - which provides links to many useful pages. You can try infrared and visible images,
- Weather forecast and related news on "your" ABC, and;
- Weatherzone has lots of useful stuff beside a satellite map, including rain radar and a lightning monitor.
Other servers:
- The MTSAT-1R satellite which takes all these weather pictures is operated by the Japanese Meteorological Agency. They provide whole disc images and animations.
Page last updated 2024-05-14
James Cameron - james dot cameron at anu dot edu dot au