Storm Chase Report: NSW Northern Rivers 17 January 2010Indications were that the northern parts of the region would not fire until later so Rodney Wallbridge, Jason Paterson and I headed south to Grafton. This was the sky near Casino just before we left.
A storm had gathered strength west of Woolgoolga by the time we arrived in Junction Hill (just north of Grafton) and was tracking NNE.
The updrafts were powerful with some overshoots though the base was a bit elevated.
Other storms were gathering in a more favourable location to the southwest around the Nymboida area. Despite the heat (and a bit of sunburn!) we enjoyed this developing storm system which would be our target for the next three hours.
There was not a great deal of observable lightning but the high contrast structure was very nice. Microbursts were certainly a feature today.
We let the storm develop just enough before the decision was made to see what the storm was producing - ie. I wanted to get some hail. We drove through Grafton and by the time we were crossing the Clarence River strong gusts were hitting. The lightning had certainly ramped up too.
A shelf cloud structure was to the west but we proceeding south through South Grafton then out the Raleigh/Nymboida Road (almost exactly the same location as the chase on 28th November 2009). Wild torrents of wind blown rain battered the area. The visibility seemed to be zero at times. We crawled southwards to find a spot clear of any immediate danger from falling trees. Wave after wave of microburst energy smashed around. Numerous shotgun CGs hit - it was awesome! The only disappointing part was the lack of large hail - only some 1 to possible 1.5cm stones fell. The initial W-SW gusts switched to E-NE from the rear flank.
The slow moving nature of storms today ensured the onslaught lasted quite a while - but did cause damage in Grafton and South Grafton.
We drove back north and out the core then took the Lawrence Road from Grafton northeast and moved straight back into the wild weather. Again torrents of rain fell in the microbursts and some small hail.
Just near Lawrence we were clear of the rain and able to see a spectacular microburst to the west.
A couple of pics then we had to race northwest to get through a tree lined road before that microburst caught up with us. We just made it although it looked dodgy at times.
Back on the Summerland Way at Whiporie the storm was again looking beautiful with powerful new updrafts. Other activity to our SW only had our attention briefly.
The aim now was to get back into the main storm. We took a gravel road which cut across to Coraki saving over 30ks of driving had we gone to Casino then back ESE. The road was actually quite good (for gravel) and our timing ended up fairly ideal, exiting the forest straight into the storm's core again! Another microburst and some 1 - 1.5cm hail too.
This storm weakened very rapidly after that.
We moved WNW to near Casino as the sunset drew near. Other cells were developing - one initially southwest of Casino had some lovely structure though high based. The lightning was not very frequent but there were a number of clear air CGs.
Another storm developing very quickly to the west of Casino and ended up tracking over Lismore Alstonville etc into the evening. This gave an awesome display of lighting, though infrequent at first. Being around sunset produced some lovely colours.
At great chase and a nice way to mark the 9th anniversary of the Casino Supercell.
Michael
