What an incredible afternoon with hailstorms through Sydney. The Great Western Highway was near impassible with hail drifts covering the road. Hail size was up to 2 to 3cm measured mostly 1.5 to 2cm diameter. We began our day at Quakers Hill and then moved to Rooty Hill. The day started relatively slow with cumulus struggling over the mountains occasionally taking off then glaciating and collapsing. It was the storms that developed near Lithgow that eventually consolidated and took over.
The storms became anchored in the low level flow and gradually moved slightly to the left of the mean level flow. Harley and I then decided to move from Rooty Hill to Penrith – deciding the most ideal vantage point proved tricky given the deviant flow. The Penrith Lakes region was almost ideal and allowed full view of the storm structure with precipitation but perhaps a touch ambient light creeping through making contrast a little tricky. A nice wall cloud developed under the well structured tiered structure! Occasional lightning was observed. Rain began to drop and the storm making its move, it was time to move! A touch slow through Penrith but no need to panic. We headed for an eastern vantage point only to head all the way to Eastern Creek. Another extensive base had developed east of Penrith and and both Harley and took note of this and remained stationary. The storm literally exploded overhead and we eventually made our way to the Great Western Highway. After a brief phone call from my cousin Stephen about a hailstorm he had just witnessed and wow! Hail drifts! Just like that right near the highway and within about 100-200 metres from no cover! Turning onto the Great Western Highway was fun and the adventure was about to begin – very rarely do you have 3 lanes virtually to yourself. Cars as per usual parked under bridges but we kept heading east. The depth of the drifts became sufficient almost to stop the vehicle from moving – probably up to 10 to 15cm deep in places. Hail piled up on the car windscreen as well like snow! It was simply crazy. Hail sized were estimated to be between 1.5 to 3cm – measured later as maximum 2.5cm hailstones. Gradually the hail drifts thinned somewhat and we made our way further east with a substantial base evident. At Toongabbie, we stopped for a brief shot of hail on the windscreen. Indecisions – should we head back to photograph the hail drifts? This changed to an intercept of the next cell coming towards Blacktown. More hail! Believe or not, we ended up through to Seven Hills through more hail once more and then watching a beautiful base and updraft flanking line! Decision again to head for the hail drafts took us through another hailstorm and more hail covering the lawns. Back onto the highway west bound and closing in on the hail swathe – traffic jams. We had no way of not only getting to observe the hail drifts but to get a good vantage point to observe the impressive mammatus now appearing! Wow! This was some of the best mammatus had observed in Sydney personally! The rest of the evening we attempted to photograph and measure hailstones. Largest hailstones were in the main hail drifts near Eastern Creek bordering Rooty Hill. Hail still lay on the ground in patches.