7th of July, 2018 - Cold Outbreak
A fairly benign system by longer term standards but this cold front still delivered a light dusting of snow to the Oberon Plateau and Mt Canobolas and Sunny Corner - in the range of 1cm to 3cm. Blackheath had snow flurries through the day but it was never cold enough to settle. Even though the sleet and snow was typically falling at around 2C to 4C, the relative humidity was around 80%, so the classic evaporative cooling effect comes into play. Flakes that would otherwise melt in relatively mild conditions are able to survive their fall to the altitude of Blackheath (and even a few soggy bits and pieces to Wentworth Falls) due to the relatively dry air. It was very windy throughout this system and wind-chill overnight on Saturday and into Sunday the 8th was around -10C at times. So, not a very snowy system by any means but it sure was cold, with the temperature below 5C for most of Saturday the 7th and often closer to 3C or 2C during light showers.
16th and 17th of June, 2018 - Cold Outbreak
This system was notable for its coldness throughout the layers from 850hPa to 500hPa but not large amounts of moisture this far north. The Sydney weather balloon info for Sunday morning - approximate figures are: -33C at 500hPa, -11C at 700hPa and -2C at 850hPa.The Oberon Plateau saw snow falling by Saturday afternoon with a light settling. By Sunday morning, numerous places below 1000M also saw snow, like Dargan, Portland, Orange, Milthorpe and of course Oberon. The cover on the higher ground varied a little (not unusual during shower activity) and around 8cm was measured at Shooters Hill and a similar amount at Black Springs - both of these settlement locations are over 1200M. Blackheath had light sleet and snow showers late on Saturday and some light snow into Sunday morning where it settled briefly but only amounted to a dusting due to our rain/snow shadow effect to the east of the Oberon Plateau. Our best directions in the Blue Mountains for snow are from the south and south east and also when the frontal system has such strong instability that it can bring some snow from most directions. So, not a major snow event but a fun one, especially for those that visited the Oberon Plateau. I will add more to this report as time allows.
A light snowfall occured on this day, Shooters Hill and places like Porters Retreat observed snow showers and a light settling. The Blue Mountains didn't see snow from this event.
11-5-18 - Cold Outbreak
This system turned out to be cold throughout the layers of the atmosphere but lacked moisture. -32C at 500hPa, -12C at 700hPa and around -2C at 850hPa is a colder than average system for May. Thursday afternoon saw the first frontal band arrive at Shooters Hill at around 4pm. At 2pm it was around 12C out there and by 4:30pm it was 1C. Light snow occured at just after 4pm but did not settle. Overnight on Thursay the snow become heavier on the Oberon Plateau at times and by Friday there was a nice settling (a few cm) at Oberon township and even as far east as Hampton. Sunny Corner saw a nice settling to a few cm and even Lithgow township observed snow showers on Friday. Blackheath didn't really see anything more than snow showers at times on Friday morning. There was a lack of moisture over this way, as the system was drying out as it slid across the Oberon Plateau.
Contrary to local lore, our lack of snow in Blackheath is not because it gets too windy but rather its a lack of moisture and sometimes a lack of surface level cold, that prevents us from seeing a good settling these days. I've seen many good settled falls on the Oberon Plateau during strong winds and also numerous good falls in Blackheath with winds of 100km/r and more. You can have snow not settling in light winds or strong winds and also snow settling well in strong winds or light winds. Its not the wind that is the problem, its the lack of low to mid level moisture and also our lack of significant, lower level cold, during cold fronts these days as well. In the old days, the Oberon Plateau may have seen falls of 15cm to 30cm in their bigger falls and we would see maybe 5cm to 10 across the upper Blue Mountains. These days, the OP more often sees 5cm to 10cm and the upper mountains sees snow showers and perhaps a light settling if we are lucky. Of course, bigger falls do occur across the Blue Mountains but much less often than they did in decades previous.