NSW, VIC, TAS: Front brings gales, snow
The front that can be seen on the 10am surface chart above brought brief but unexpected sub-alpine snow to SE NSW as it passed this morning, with gales and strong winds to a wider area.
Radar showed a band of light to moderate precipitation about 50km across moving through East Gippsland and arriving at the VIC/NSW border around 3.30am. This continued to move NE across the Southern Tablelands arriving in and to the east of Canberra around 8am then decaying as it moved into the Illawarra. Upper air temperatures measured by the sonde balloon network at 10am were not particularly conducive to snow, with 850hPa (about 1.4km elevation) temperatures around 0 to -1. However, an upper cold pool too small to be detected by the upper air network may have been responsible, and the timing of the precipitation meant that surface temperatures were low enough for snow to fall down to 600m across much of the NSW Monaro and probably the higher parts of the VIC East Gippsland.
Radio, Bureau and personal reports indicated heavy snow fell briefly at Michelago, Bredbo, Bungendore, Braidwood, Tarago, Nerriga and 15km E of Canberra at Wamboin. Accumulations of 1.5cm were reported on light aircraft wings at Bunyan, 12km north of Cooma, up to 5cm was measured on the ground in parts of Cooma, and a light coating was seen on higher hills around Canberra and Googong. Light snow is also thought to have fallen in Jindabyne and Queanbeyan.
Snow was reported down to the 500m level in TAS, with Lake St Clair measuring 6cm on the ground at 9am.
The front gave Wilsons Promontory a 10-minute mean wind speed of 104km/h (gusts to 117km/h) at 4am, and the Prom reported gale force winds at every observation through the day. Other reports of high winds in VIC, NSW and TAS are in Highest gusts and High AWS wind reports below. Hogan Island, 50km E of Wilsons Promontory, recorded a wind run (total amount of air to pass the station) of 2,963km for the 48 hours to 9am Tuesday, an average wind speed of 61.7km/h.