Storms and Wind - 2nd to 7th July 2007 Page 1

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After nearly a month of blocking highs and south easterlies the promise of some significant fronts loomed. While I had done well rain wise from the south easterlies, the north was in desperate need of rain. This had the potential to do just that. The synoptic below shows the situation on the 2nd.

All manner of weather was on the forecast and ranged from severe winds, hail, cold and storms. Windy it certainly was and I recorded a gust of 78km/h during the morning of the 2nd and 3 hours of gusts in excess of 50km/h. East of the ranges the BOM issued a severe weather warning with a wind gust to 98 km/h observed at Strathalbyn around 1 pm. Meanwhile on the plains it was calm and business as usual. The rainband with the first front arrived in the afternoon and bought with it just 6.75mm for my location. 9mm for Meadows township, but the stand out falls were in the central hills where falls over the inch mark were to be seen. I was in the area soon after the rain and water was running in rivers from the hillsides. It came down with a rush. But for me it seemed the low totals were set and more disappointment was to follow.

The 3rd.

Tuesday the third was a day of temperature aberration It rose to an amazing 15.4 degrees (over 20 degrees on the plains) which is the highest since May 29th. After a month of 10 degree maximums it felt positively balmy. This warmth and second approaching front saw some significant instability develop in the late afternoon with some prefrontal cells pop up in the gulf. The view at dusk from Coromandel valley was quite spectacular and I snapped this 2 image panorama with my camera phone. - IMAGE HERE

These afternoon cells hot the ranges and exploded with solid cores. As can be seen in the radar image to the right the torrential rain centre was barely 2km north of me over Meadows town. This is a regular stream and can be rather frustrating to watch it come so close. In the early evening (~7:40 pm) the northern plains near Avon and Owen copped a line of storms. These were very impressive with cores as intense as the radar can record! With a slight "left movement against the streams they were also pumping out lightning and thunder. See radar image below left. I did manage one direct hit from a tiny little cell around 8:40pm. See radar image below right. Pathetic in comparison to the others it was still torrential and makes you wonder just how intense inside these other cells were. Typical of my location - a storm dead spot!

My being out of the rainfall streams with this system was beginning to show in the rainfall recordings. Just 10mm for me by the morning of the 4th, 14mm for Meadows town (sooooo close!) and yet again falls above the 25mm mark in the central hills. Mount Barker district had received near 40mm in the previous 2 days. Many other northern Onkaparinga catchment zones recorded that and more. Maidment road, halfway between Birdwood and Charleston, totaled 47mm in the previous 48 hours to 9am the morning of the 4th which included the previous nights 28mm. I am well and truly missing the best and most intense rains yet again!

I did spend some time trying to photograph the lightning which accompanied this initial line, but it was to rain wrapped and all intra cloud and hidden from view.

The 4th

Yet another front was on the way. This one had the forecasters issuing warnings galore!

Rightly so as reports of severe winds and even a tornado near Coulta on the west coast came in! Brian Foster from Coulta on the Eyre Peninsula captured some amazing images of the tornado damage to big old gums near his farm. See the pics in THIS GALLERY.
The line of severe weather could be seen approaching the Adelaide Coastline on the radar. Warnings were broadcast on the radio as the City and Hills braced themselves.

But then just as we were all expecting to get wet - it died! Just like that in few frames of the radar the rain fizzled away to nothing and arrived over Adelaide with barely a drop. It is one of the most complete collapses of a rain band I have seen. The small loop of 6 radar snippets to the right shows how quick and comprehensively it all fell apart. The rain may have collapsed but the winds certainly didn't. Up at my spot in the ranges the wind was gusting in excess of 70km/h peaking at a strong 83.6km/h. The house is sheltered from direct winds and I would hazard a guess that the gusts in the open would have been in excess of 100km/h!

The centre of the developed low was heading straight for the SE coastline with a rather low central pressure of just 991hPa. Some of the stronger gusts of wind recorded are as follows.
120km/hr at Cape Willoughby.
117km/hr at Neptune Island
91km/hr at Roseworthy.
Impressive winds indeed!

Meanwhile the combination of a king tide and these gale force winds began to cause some problems along the Metropolitan coastline. The Port Noarlunga jetty was hammered. Some damage to the structure. The Semaphore jetty was also damaged and the Largs jetty was reported to be in danger of collapsing. The O'sullivans Beach boat ramp had rocks, mud and water littering the car park. Minor flooding at Old Noarlunga,and the Commercial road bridge at Port Noarlunga was closed due to flooding from the Onkaparinga River. But Glenelg, St Kilda and Port Adelaide suffered the worse with lots of sandbagging in attempts to save property!

Some Clippings from "The Advertiser" can be seen in the gallery - HERE

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