Storm Chase - Gunnedah to Boggabri / Gunnedah - 29 November 2010
Over the three days from Sunday 28 November to Tuesday 30 November, I decided to try some storm chasing across the North West Slopes of New South Wales.
I left Sydney Sunday morning and drove to Maitland then Singleton to investigate weather conditions. Unfortunately no thunderstorm activity occurred in the lower Hunter Valley. Some weak convection was occurring to the north around the Barrington Tops but cumulus clouds kept collapsing. It was a cloudy day and cirrus stratus cloud dominated much of the sky. I also noted a rain band to the south including thicker cirro stratus and alto stratus cloud formations. Late afternoon, I decided to drive to Scone to keep away from the rain. I spent the night at Scone.
Monday, I drove to Tamworth and did some weather checks at the local library. At Tamworth a heavy but brief rain shower occurred over the city centre early afternoon. The weather models suggested that Gunnedah would be a better place for thunderstorm activity. I then drove towards Gunnedah under cloud but near the town, I broke out into clear skies and much sunshine. I also saw some cumulonimbus cloud towers to the west. I did a second weather check at the local library and decided against chasing the cloud towers as the storm cells did not appear to be significant. I waited in Gunnedah for around 3 hours which included my lunch. At around 3.30 pm I saw a large developing storm well to the north west of town. Rather than wait for the storm, I decided to intercept it. I drove out towards Boggabri and just outside town, I intercepted the storm.
There were two storm cells being a smaller southern one and a much larger northern one (Two photos attached). The main northern storm appeared to be a complex of cells and anvils that had merged into one another. Occasional cloud to ground lightning was seen including one bolt that was close by. One storm cell built close by and dropped a significant rain shower where I was located. I decided against driving any further into it because a new separate storm was building to the east. I decided to watch it, photograph it and follow it as it displayed some structure. I then decided to chase it back towards Gunnedah. I was able to catch up with it just as it reached its peak. As I was driving underneath it's base, a portion of the base just to the east of the road started to show a slight green tinge. However, I did not experience any hail but I did encounter strong rainfall and moderate winds. I drove through the core and then into clear skies on its southern side. I drove a couple more kilometres south where I parked the car off the road and waited. I let the storm core catch up with me and overtake me. Again, there was significant rainfall and cold winds and allot of within cloud lightning. Again, I did not experience any hail fall.
Following this, I drove back towards Gunnedah and I noted the storm had merged with the other storm and was losing its structure. Another small storm built close to town and I decided to chase that one. I caught up with it and again encountered a heavy rain shower. At this stage, storms were losing their structure and were weakening. I decided to spend the night in Gunnedah.
On Monday 30 November, I returned back to Sydney via Quirindi. I have photos of rain cells and weak storm cells but I will add them under a separate post.
Jimmy, I received your text message following this storm (Second storm). This was the storm I was concentrating on. Following the chase, it appeared that thunderstorm activity was starting to wane across the region and no further storm activity occurred. I was not aware of new storms close by. Following your text message and looking at my maps, I realized that I had no chance of driving to Coolah or Dunedoo in time to catch the storm as suggested. I was too far away and nightfall would have caught up with me.
The photos referred to are provided below. They are taken near Boggabri approximately 35 to 40 km North west of Gunnedah between 4 pm and 6 pm. The first two photos are looking west while the second two photos are looking east or south east.
Harley Pearman
