21 20 19 |
Dew Point Temperature (º C )
Temperature (º C )
|
BAMOS March 2017 |
21 |
18 |
|
|
|
17 |
|
|
|
|
17:00 17:30 18:00 18:30 |
|
|
95 |
|
|
|
90
85
80
30
20
10
17:00 17:30 18:00 18:30
Wind Velocity ( km hr -1 ) 0
17:00 17:30 18:00 18:30 1000.0
999.5
999.0
998.5
998.0
150
100
6
4
2
50
Wind Gust Velocity ( km hr -1 )
Relative Humidity (%)
Atmospheric Pressure ( hPa )
17:00 17:30 18:00 18:30
Rain Rate ( mm hr -1 )
0 17:00 17:30 18:00 18:30
Rainfall ( mm )
0 17:00 17:30 18:00 18:30
Time
Severe thunderstorm and hail storm in the Queanbeyan area 11 February 2016 .
After our experience of a severe hailstorm on 29 January 2016 it was Queanbeyan ’ s turn to be impacted by a similar event on February the 11th . While the thunderstorm skirted our site , I am providing data and observations on its effects here at Gilmore , about 8 kilometres to the south west of the Queanbeyan CBD .
The 9am Observations : The weather was partly cloudy with two octas cirrus / cirrostratus and two octas small cumulus at 2,000 feet , moving from the south southeast . Temperature was 21.5 º C , dew point temperatures 16.2 º C , relative humidity 72 % and wind , southeast at 6 km hr -1 .
By 3:00 p . m . the temperature was 28.7 º C , dew point temperature 16.9 º C , relative humidity 46 % and wind , east north east at 15km hr -1 . Cloud : a sky total of six octas consisting of three octas cirrus , four octas large cumulus , one octa cumulonimbus tops to west southwest , southeast and northwest . Thunder was heard at the time of observation . As was the case with the earlier storm in late January , moisture levels were higher than usual for the Canberra region .
The storm developed in much the same location as the earlier January storm and tracked northward towards the southern suburbs of the Tuggeranong Valley . The storm appeared from the radar to veer to the right as it approached the southern end of the Tuggeranong Valley and passed about 2 – 3 kilometres to the east of our site around 4:55 and 5:05 p . m . There was frequent lightning and almost continuous thunder during its passage .
Light and variable winds earlier became light northeast before a strong gust to 55 km hr -1 from the south south east occurred at 5:25 p . m . as the storm was located over Queanbeyan . Rainfall commenced at the station at 4:50 p . m . with a maximum rainfall rate of 12.2 mm hr -1 at 5:00 p . m . with some light small hail . Rainfall ceased by 5:15 p . m . with a total of 1.2 mm recorded . The winds veered from a northeast direction through east to southeast during the event . The temperature varied from 30.7 º C at 4:00 p . m . to a low of 20.4 º C at 5:00 p . m . rising to a secondary maximum of 25.0 º C at 6:00 p . m .
The dew point temperature fell sharply from17.0 º C at 4pm to as low as 10.5 º C at 4.55 p . m . before rising to 18.5 º C at 6pm ( Figure 5 ). There was a corresponding rise and slighter fall in the relative humidity . As the storm moved over the Queanbeyan area , I estimated by trigonometry , that the top of the cloud was at about 43,000 ’. As reported in the media there was considerable damage in Queanbeyan from the hailstorm .
Figure 4 . Evolution of meteorological observations from Gavin O ’ Brien ’ s personal weather station in Canberra , 1700 to 1850 AEDT 29 January 2016 .