Hey g’day gang! Sorry for my absence, as I’ve been very busy. But I’ve made it to Merimbula down on the NSW South Coast!
Backtracking on my Corryong reports for this previous event, including low and high temperatures, and any recorded rainfall.
Here’s my report for Thursday January 5th
, which proved to be a fantastic storm day across the Upper Murray! Corryong Airport
– low: 16.5°C; high: 31.7°CKhancoban Airport
– low: 12.7°C; high: 29.1°C
My fiancée and I left town around 11am and went for a drive over to the Cudgewa Bluff Falls in the Burrowa-Pine Mountain National Park, then over to Tintaldra and along the Murray River to Walwa and Jingellic, and finally ending up in Khancoban. We returned to Corryong around 6pm.
Skies were already ripe with instability as we left town, with convection initially developing towards the south (Lake Dartmouth, Omeo, Mount Hotham and Falls Creek). By midday, storms were firing over the entire Victorian High Country, but towers were exploding high over the mighty NSW Snowy Mountains as well! Temperatures across the Upper Murray were soaring quickly towards 32°C with humidity to boot!
During the drive from Jingellic to Khancoban after lunchtime, a MASSIVE multicell thunderstorm had powered up over Mount Kosciuszko and the headwaters of the Murray River, and this storm became my main focus for the next hour or so as it moved northwards! The cumulonimbus was towering to a good 40,000 feet, with the most vigorous updrafts breaching the tropopause, bright-white in the hot summer sun; the base was a dark, boiling, angry mess.
Just after 2pm, my fiancée and I reached Khancoban Pondage, but within 10 minutes the storm moved in! Heavy rain and possible hail were being dumped over the Swampy Plain River Valley to the south (it was extremely dark in that direction); thunder could be heard on average once every 15 seconds, and flashes of lightning could be seen. Although it collapsed and died before reaching Khancoban, a dark and ominous gust front with whale-mouths swept overhead, accompanied by a powerful blast of cooling, but howling gale-force winds that lasted about 5-10 minutes, lashing at the trees and making the lake-surface very choppy! The outflow sent all the people at the lake rushing for cover, but then it ended as quickly as it hit.
But the same outflow winds from that storm helped kick off a much more severe thunderstorm just to the west, over Corryong itself! The skies in that direction grew increasingly dark and threatening until the storm finally broke around 3pm. Khancoban only caught the eastern fringes of this cell (spitting rain and fairly gentle cooling winds), but thunder was quite frequent, on average 3-4 times per minute, at times almost overhead in the storm’s anvil! A few CC and intra-cloud flashes and even a couple of dangerous CG lightning strikes were observed to the west in the storm’s core.
According to reports from my parents who were back in Corryong at the time, the storm lasted about an hour in town, dumping intense rainfall and bringing frequent, dangerous lightning! And despite the severe thunderstorm warning that was in place at the time, no large hail resulted.
Back in Khancoban, the storm finally ended at 4pm and within 30 minutes the rain stopped and the Sun was back out, although further shower and thunderstorm activity was away in the distance, particularly behind the main Kosciuszko ridge and towards Albury/Wodonga. My fiancée and I went for a swim at local pool for over an hour.
At 5:30pm, we drove back to Corryong, arriving by 6pm. On radar, a new cluster of multicell thunderstorms was edging its way slowing north in our direction; several huge cumulonimbus towers could be seen to the south/southwest, with new convection continually going up ahead of them!
From around 6:30pm onwards, the sky to the south became very dark and boiling, contrasting beautifully with the sunlit foreground, while the top of the storms soared high overhead, finishing in one dull-grey anvil that spread off towards the east, with mammatus hanging down; the base of the nearest updrafts just south of town were wind-torn, with a bit of a shelf cloud developing (these updrafts helped kick up a new, fairly weak, separate storm cell that headed northwest towards Cudgewa, Walwa and Jingellic), and rain and hail being dumped in torrents in the distance. By 7pm, booming thunder could be heard in the distance (on average a few times a minute). Ten minutes later lightning was visible in the rapidly gathering darkness, and quickly began ramping up as the storm edged closer; the Sun vanished behind the impending storm around 7:15pm. Most of the lightning was just intracloud flashes, but a couple of CCs and a few potentially dangerous CGs were visible.
The thunderstorm’s shelfie swept north into Corryong just around 7:30pm, accompanied by cooling, blustery winds, light spitting rain and a wild, turbulent, at times tornadic sky. Alas, the main cell made a right-turn and swung towards Khancoban, weakening as it went along. By 8pm, after spitting out one final flash of lightning and clap of thunder, the storm ran out of steam and died.
But as the Sun went down, it caught the dying storm and created a beautiful double rainbow! The sunset itself, complete with anvil residue from other decayed storms to the west and southwest, was also magnificent. By nightfall, the show was over and a pleasant, starry evening followed.
While it was admittedly not the best storm day, as I never scored a direct-hit from any of the cells that developed, and steering was poor, it was a great storm day nonetheless. Plenty of instability and amazing convection, some good storm structure, the usual contrast between sunlit foreground and stormy darkness, blustery winds, lightning, and some very welcome heavy rainfall!
Khancoban Airport only scored 0.6mm of rain, as opposed to 10.6mm at the Corryong Airport (and 11mm in my private rain gauge). Only around 1-2mm was predicted for the Upper Murray on Thursday, so it just goes to show how erratic, localised, and intense the storms were.
A pity the Yarrawonga radar was out of action, so I was forced to rely on the Melbourne, Canberra, Wagga Wagga and Bairnsdale radars.