12-15th September 2008 Wintry Burst

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3 days of nasty winds preceeded the arrival of a late burst of winter. Regular gusts to 60km/h bombarded my part of the hills starting on Friday the 12th September. Rather vigorous approaching fronts were the cause of the winds and let up they did not! All day Friday, all night through to Saturday the 13th and on and on through the day. The satellite image from the Saturday morning was very impressive with an amazingly tight thousand km long troughline! A small snapshot of this image along with the associated synoptic chart form the 13th can be seen below. Click on the satellite image for a larger more detailed version.

Saturday was also pretty warm temperature wise and saw us with our hottest day following winter. Above 30 degrees in the northern areas, 28 in the City and 22 in the ranges! My hottest day since April 24th. Awful conditions and in such drying weather with the continuation of the strong winds raised dust preceeds the front.

The troughline arrived late Saturday evening with a bit of bang and some localised torrential rain. In fact the radar filled in incredibly rapidly on hitting the Adelaide coast and Ranges. The radar image to the right graphically displays this. Although not represented in this radar grab the heaviest most intense falls were as always over the Northern hills and suburbs. Nevertheless I did quite well with 7mm overnight, the highest fall being 15mm at Lobethal. Almost enough to offset the recent drying effect of 48 hours of gale force winds. Also accompanying this early band of rain was a reasonable amount of lightning. Unfortuately it was all up in the clouds and too rain wrapped to be photographed. Sunday 14th arrived and STILL the winds blew. Most of the day was dry with very few showers around the place, but did I mention wind yet? A further frontal system was on the approach and severe winds accompanied it, so much so the BOM issued a storm force wind warning for much of the southern part of the state. And it arrived with force! Sustained winds above 60km/h were recorded at my location and my anenometer is in shelter! The wind could be heard roaring with incredible impossible to imagine power over the ridgetops surrounding the house. The noise was fearsome. Every so often a low pressure eddy would reach the house and the roof would creak and groan in complaint. My neighbours verandah tried to lift off, trees were down and the gusts must have been in excess of 100km/h. All night and for most of Monday 15th this continued. The state was hammered!

By the end of Monday 15th the wind stats were impressive. Highest wind gusts recorded were 117 km/h at Neptune
Island, 109 km/h at Cape Willoughby, 106 km/h at Mt Crawford, 102 km/h at Cape Jaffa, 100 km/h at Cape Borda, and 96 km/h at Coles Point, Port Lincoln and Stenhouse Bay. My highest gust was 69km/h in the considerable shelter of the ridges!! As previously mentioned plus 100km/h on the ridgetops are a certainty.

Rainfall to Monday morning was patchy. Just 4.5mm at my spot. Highest fall was 15mm at Bridgewater from an early morning thundery cell. Such falls were locally the exception rather than the rule. Early morning did see a reasonable amount of thunder and lightning, again all hidden up in the clouds and again completely non photogenic. Mondays morning radar grab was rather impressive with 2 distinct squall lines clearly visible. (see image to the right) As always the most intense and impressive falls were to be seen over the northern ranges with falls approaching 5mm falling in just 5mm from isolated locations. Nothing even approaching this intensity was seen around my location. The air above was cold and the intense cores were delivering more hail than rain. Hail was reported from most central (and south east) locations and was quite thick with localised spots reporting thick hail drifts in collection points. I received a couple of lightish hail showers on and off during the day, but nothing approaching a decent intensity. The hail that did fall however was of a decent large pea size instead of the more usual wintry tiny hail that usually falls. The small hail was responsible for see-sawing temperatures during the day. Most of the day hovered between 8 and 10 degrees with the maximum of just 11 degrees occurring in the early morning hours at 1:30am!

Sunday too was a very much colder day at a chilly 11.5 degrees an amazing almost 11 degrees colder after the previous days (saturdays) hot 22.2 degrees!!

All up an interesting event. More impressive for wind than rainfall unfortunately. Overall very little rain to offset the evaporation of the incredible wind, even in the cool temperatures following the fronts arrival. 4 days of gales in my part of the ranges left trees down and local building damage. Wider speaking thousands of homes were without power as trees took out power lines from Kangaroo Island to the mid north. A wild few days.

I did snap one or 2 pics as the event unfolded. No lightning and wind is a hard thing to capture in a still image. But one or 2 hail pics were snapped, including some excellent shots sent to me from Peter Coombe at Lobethal. The gallery can be seen HERE, in the meantime a sample.