Sunday, 27 January 2013

The BoM gets it mostly right

In a recent post I followed the non-fulfillment of the official Bureau of Meteorology (BoM) weather forecast for the last week.  For the Saturday - the day after the series of forecasts ended - the forecast mentioned the possibility of Storms and a fall of 10-25mm.

By 1500 there had not been a drop of rain and according to the radar the nearest storm appeared to be about 150km away, and slipping to the South.  References to followers of Onan were heard to pass from my lips.

By 1605 the situation was a little different:

By 1700 it seemed quite likely we were going to get a drop ....
 and by 1815 it looked as though we were going to get rather more than a drop as BoM issued a local SEVERE THUNDERSTORM WARNING.
No rain has fallen at 1815 but the text said the storm would hit Queanbeyan at 1900.  The rain started about 1850 and about 1905 the Heavens opened,
the lightning flashed, the thunder roared and the power went off.  It continued to pour like that for the next 45 minutes.  Our drive was awash up by the house (note the brown torrent over by the bushes) and was pretty eroded by 1945.
Whiskers Creek had given up the fight with the culvert by that time and it will be interesting to see what shape it is in when daylight returns.
Our nearest dam,; which at 1800 was 50cm lower than it was about 2 months ago, is now fuller than I have ever seen it.

My weather station couldn't keep up with this downpour, recording 32mm in the period.  The old rain gauge, which is still in situ, recorded 55mm in that period. so  an adjustment will have to be made to my weather station records.  We have totaled 63mm by 0500 on the 27th.

I rang Country Energy (using an old keypad phone) about 9:30 and they said there were multiple problems being worked on and no time of renewed service was available.  In fact it came back on at 0430 (and the resultant lights going on etc woke me which is why I am doing this now.  So the guys worked through the night fixing stuff: big bouquet to them.

The Canberra Times article gives a wider perspective.

Early in the morning of the 27th it seemed that another serve was geading our way
Fortunately it stayed out to sea!

On going down to the Creek the culvert was invisible.
After about an hour of use of various tools and letting the torrent wash the detritus (a key strategy to let the water do the work) through the pipe to the lower reaches of the creek ...
 ... flow was re-established.
 Amongst the tools used was my chainsaw.  The size of this tree trunk is indicated by comparison with my hat!
Here is some more of the stuff I pulled out: after it has dried I estimate there is about a week of firewood in this heap.
Having got that (related to a remnant of a WA cyclone) out of the way 2 days later the BoM promised - or at least forecast - more showers, related to an ex-cyclone from Queensland.  That led to it raining more or less lightly, more or less continually from about 1830 on 28 February until 0630 on the 29th.  We only scored 29mm out of that and not much erosion.  I did go and open all the gutters to let the water run away as I could see no point in using electricity to pump it up to the main tank and have it simply overflow and run back down.

1 comment:

Mary Chamie said...

Quite the weather you all are having these days, Martin. Stay safe.