TOP OF PAGE Spectacular "Whirlie" wind A warm day
with clouds forming above the range, the wind suddenly picked up and
I noticed a dust swirl forming on the top of a hill. What started as
an ordinary whirlie grew into something quite spectacular. The centre
or the whirlie remained stationary as the intensity of the spin grew.
As it peaked it was drawing leaves and dust and small twigs from over
120 metres away into the centre of the funnel. The funnel itself rose
in a twisted "tornado" fashion to a couple of hundred metres
in height where the contents of what it had picked up from the ground
where thrown out in a fan fashion above the funnel. The centre after
peaking moved approx 60 metres where it blew itself apart on a large
pine tree wind break, but not before showering the whole area with dust,
leaves and small twigs. The whole event lasted about 5 minutes and the
only record was a sudden spike in wind speed, which due to its distance
from the anemometer and localised occurrence only just caught the edge,
and myself! When you need a camera the most!!!!!
Good Rains
26th March 2002.
TOP OF PAGE Finally a reasonable rain After 47 days of
dry weather, during which only 2.75mm of rain fell (0mm recorded in
most areas) a frontal system brings a much needed drop. A long way to
go yet before we can declare a "break" in the season.
Cold Front
11th May 2002
TOP OF PAGE One of the disadvantages of living on a hill
is that the wind blows! After a long calm period, the classic approach
of a cool change brings strong N-NW winds accompanied by a rapid drop
in barometric pressure. 2002 has been very dry to date with only one
significant rain in March and this front did not change that, giving
up only 0.25mm of rain with its passing.
Season
Break? 15th May 2002.
TOP
OF PAGE Effects of Rain, Droughtbreaker & Cold Front.
The image below highlights the effect that rainfall has on both humidity
and temp. As can be seen in the 2 high-lighted selections, with each
rain the humidity rises and the temperatures drop. This is especially
notable in "selection 1".
Note also the rapid drop in barometric pressure as the change approaches.
The heavy rain band associated with the front (selection 2) passes and
immediately the barometric pressure begins to rise. This is a classic
example of a cold front. This change bought the heaviest rain (note
the green rate line) and the highest falls (note the blue line)of the
year to date. Is it the season break the farmers have all been waiting
for?
15th-16th
May 2002. Localised heavy falls
TOP OF PAGE The same front described above, demonstrated
quite clearly how patchy our rains can be. In the map below the falls
are highly variable, with local heavy falls. The rainfall "cut
off zones" are like drawing a line. Take for example the rain recorded
at Meadows of 36mm and compare that with our recording of 25mm. We are
less than 2km from the town, but it was like someone drew a line in
the sand and said "No more rain this side!" Quite amazing..............
More Rain
18th May 2002.
TOP OF PAGE Rapid Baro Drop and LOTS of rain (again)
Another front on the way and check out the speed of the barometric pressure
drop. This one also bought good rains, some areas receiving over 100mm
in the Mt Lofty Ranges. First it could not rain, now it seems, it can't
stop! Check out the 7 day rainfall bulletin below, more rain in 7 days
than has been received all year. I recorded 86mm in the same period
CALM!
24th-25th May 2002.
TOP OF PAGE Unusually Calm Weather More than 12 hours of
dead calm weather is unusual enough, but in late May on the top of a
hill!
