Extreme Heat With Storms in the Northern Rivers: Friday 26th December 2003
by Dave Ellem
Shear was pretty weak on Boxing Day, however
instability was moderate and there was nice low level moisture before drying
in the mid and upper levels, although there was concern it may be a little
too dry. Also, 850 and 500 temps were pretty warm, however the very high surface
temps seemed to be enough to kick some development off by late morning.
Nothing really got well established but I headed out at around 1pm to the Tucki area to observe some new towers which were going up and anviling out south of Casino. It was awful being out in heat which was around 38C with a DP of around 24C! And what was worse was the towers were anviling out and then evaporating.
By 1.45pm I headed back home as everything looked to be drying out, however as I reached Alphadale I observed some solid looking congestus just WNW of Casino. It was the first cell of the day with a large, flat rain free base, and didn't look "junky". Rather than heading east towards home I headed for Richmond Hill. After a quick radar update, which showed the cell appearing straight into yellow, and visually observing the cell produce an anvil and new towers on its rear flank, I headed after it.
The trip through Lismore was painful as usual! The cell had produced a nice solid anvil and had a very heavy rain shaft with a nice updraft region - rather photogenic. But I was limited to taking photos from inside the car amongst the traffic.
After getting to the outskirts of town the cell looked to have one nice rounded updraft, with cloud which resembled inflow cloud feeding into the updraft. It is possible that there may have been some brief updraft rotation, with nice low level turning in the atmosphere, however I cannot confirm rotation.
I took the road out to Caniba to get to a lookout which has nice views in nearly all directions. I briefly stopped to get a pic of the decaying cell which was now over Casino. The updraft region was shrinking. Pretty disappointing now that I was near it. However a nice new cell was rapidly developing south of the original cell. Attention turned to this cell as I reached the lookout.
I sat and watched the two cells from around 2.30pm to 3.00pm, with the southern cell giving a few nice updrafts and a microburst which brought down large trees in the Whiporie area, while the cell over Casino continued to produce heavy rain as it collapsed. It did produce some spectacular mammatus though as it was on its way out, and did maintain that band of cloud for a short time before evaporating. After both cells had died the sky took on a very dry appearance, so I headed back home. More weak cells developed between Kyogle and the Nightcap Ranges but they did not last long.
Further storms developed inland and in S QLD during the night, and Anthony Cornelius scored an amazing early morning lightning show! His report can be found here.
From Bureau of Meteorology.
From Bureau of Meteorology.
From NOAA 26/12/2003 06z analysis run
Updated: 5th January 2006
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