Please note: Stories and reports of cold weather events are always welcome. I may even set up a contribution section, if time permits. In a sense, this site belongs to the weather loving community so thanks for your visits and emails.
22-5-07, Tuesday 9:30am: Our first front of the season arrives with a pop rather than a bang, up this way at least. Only 1.3mm in the gauge overnight with the frontal band that came through at around 11pm. Winds were fresh indeed with gusts over 70 kph this morning. There was hail and sleet overnight in areas above 1200 metres such as Shooters Hill, Black Springs and similar spots but nothing appeared to settle very much. At least it is windy and cool this morning with a minimum at my place of 5.1C. Certain spots in the alps did well with a nice, generally lightish cover of snow for most resorts. NB: Andrew Miskelly from Taralga was at Shooters Hill by daybreak on the 22nd and reports that it was just under 2C there with winds of around 40kt.
Stop Press: Just got an excellent email from a snow chaser that spent the night out at Shooters Hill (Monday night) and he reported wet snow, sleet and hail from this event as well as an excellent light show from the storms that approached in the frontal band last night. The wind almost blew the car off Shooters Hill as well. Wish I was out there myself but couldn't manage it this time. I will spend more time on this email/report and produce some more information soon. Hopefully there will be some chaser convergence in the form of snow reports and in-person catchups, if the season delivers. I get a steady flow of emails on personal experiences of cold fronts etc and they are always welcome. I read all of them but can't always get back to everyone.
14-6-07, Thursday, Midday: Sleet showers moved into the Blue Mountains by early to mid morning with even a few snow showers reported. There were certainly snowflakes observed in the Blue Mountains but as the temp was around 2C at the time and some rain was also present, it is usually referred to as sleet. Nothing to my knowledge settled in our area. By around 10am I was sensing a dash out to Mt Trickett (above Jenolan Caves) might be in order as some fairly decent shower activity was bypassing the Blue Mountains just to our south and heading for places like Mt Trickett and Shooters Hill.
The thing that got me really interested was that I knew the upper temps were quite cold (-26 to -28C it seemed) so I was figuring on a bit of forced lifting from the lower ground preceeding it to the east might really help Mt Trickett squeeze maximum potential out of the passing showers. It did! By midday there was around 8cm at Mt Trickett and apparently a similar amount at Shooters Hill although I didn't go to Shooters myself. In spite of being an impressive event from the south east (a fairly rare direction for cold outbreaks) the 850hPa temperatures were only marginal so snow was really only good from about 1150M ASL and higher although it was teaming with snow near Edith but not settling as much.
After initially approaching Mt Trickett via Jenolan Caves, it soon became pretty clear that my 2WD wouldn't survive for long if the snow kept falling at 1360M ASL so I found a safe spot towards Edith (although only five km or so from Mt Trickett in reality) as I didn't want to get bogged. After a time, I realised that the snow settling level was about 1150M ASL but it was very wet snow there so periodically I drove the 5k back up towards Mt Trickett as I wanted to keep the car tracks fresh in the falling snow - the only way for my car to make it up there for photos, as I had left my chains at home - silly me. On my final return to Trickett from lower ground I made up my mind to try and get all the way to the navigational building there and try and drive down the other side into Jenolan Caves. This is not something I'd ever do if there was ice on the road or if the snow level was lower but it seemed a moderately safe gamble today.
Just as I left the navigational building and headed down the hill on the 'Sydney' side I came across a council truck stuck in the snow on a steep slope. We had a bit of a chat and a laugh and then I left them alone as another vehicle was on the way to help them. Heading back through Jenolan and up the other side saw a number of small rock slides (up to basket ball size on the road) since I had driven through a couple of hours earlier, not enough to knock your car off the cliffs but they certainly would have damaged any passing car. By the time I got to 1200M ASL on the other side of the caves there was just light settled snow in patches, about 2cm deep so that extra 150M or so to Trickett made all the difference.
A very fun event indeed, even if it wasn't a classic cold outbreak. Special thanks goes to David Carroll and Andrew Newton for their updates and encouraging text messages. When you are out there on your own, its always nice to share it with someone.
19-6-07, Tuesday: Well, this day will live in the minds of Blue Mountaineers and snow lovers in general for some time. Snow was certainly a chance for the Blue Mountains and Oberon Plateau on Tuesday night but to get the amount that we did in Blackheath was surprising indeed. Theoretically it was certainly possible as when you have a cold pool interacting with moister, maritime air there is a better chance of heavier falls and this proved true on this occasion for sure.
Snow started to fall in Blackheath by around 9pm but it was wet, sleety snow at this point and heavy settling was out of my mind as it seemed likely that rain would move in from the low off the coast some time later in the evening. As we know now, this didn't happen and snow fell pretty much continually until about 3am Wednesday. Whilst the winds were south westerly at township level and below, higher up there was solid shower activity moving in from the east. So the cold pool affected westerlies (colder than the easterlies) were cold enough to turn the easterly showers into snow as they arrived. It was never heavy snow but the pea sized flakes just kept on falling and falling for hours which assured us of a good accumulation. In my backyard I recorded 10cm depth, partly because I have good exposure to SW winds where I live and also because my yard is quite wind protected and may have acted as a bit of a drift setup.
Apart from that, snowfall activity can be a bit like shower activity where different amounts can occur within close distance of each other. The temp never got below -0.5C at my place during the fall so the snow was very wet and thick and had the amazing effect of cracking branches as it weighed heavily on trees and shrubs. There was the typical silence in the dead of night with any good snowfall and then CRACK! another branch would go down. Very impressive stuff indeed. There were even some trees down over powerlines in my town as well so it was pretty dangerous in some spots.
As a result of the quite strong westerlies keeping it out to sea, the low off the coast never really moved as close to the coast as was anticipated so, combined with the lower level inversion, this prevented any rain coming in to our area and melting the snow before daybreak. Many townsfolk that were unaware of the fall could be heard crying out in delight as they awoke to a snow covered landscape in the morning. I got to bed by about 4am and was up again at 6:30am and I heard numerous folk screaming with joy when they opened their front doors to many cms of snow. Oberon area did very well out of this event too with up to 30cm of settled snow in higher spots and about 5 to 10cm in the township. Some of the drifts out there were almost a metre high.
21-6-07, Thursday: Adam and I headed out to Shooters Hill and Mt Trickett yesterday afternoon in the hope of more snow. A nice snowfall occured at about 5pm at Shooters Hill which lasted fifteen minutes where the temp got down to 0C at the time. It settled to about 0.5cm to 1cm. There were also some snow showers at Mt Trickett with about 1cm of settling. Drifts left over from the June 19th fall were around a foot deep at Shooters Hill and a little less than that at Trickett. It also snowed a little more, later in the night, when other snow chasers were out there. The Blue Mountains didn't get any snow to my knowledge from this event but a lovely frost is around this morning with a minimum of around -3C at my place.
27-6-07, Wednesday: Yesterday saw nice snowfalls across the Oberon Plateau and at places like Mt Cannobolas. There were reports of at least 6cm in Oberon township and maybe more. Cold air associated with an East Coast Low brought about these falls but due to less lifting and a not very unstable airmass, the upper Blue Mountains only saw snow showers and very little if any settling. Still, yesterday only reached 2.5C as a maximum in Blackheath and the minimum was 1C with lovely snow showers at times in the afternoon, so some impressive cold. Next morning on Thursday saw a mimimum of 0.2C and some sleet but mostly rain in the stabilising conditions.
5-7-07, Thursday: Yesterday was enjoyable indeed for the Blue Mountains with some lovely snow showers occuring by the afternoon. Upper level temps were quite cold so this allowed some handy cold air convective cells to pass over the BM at times. This instability though was mainly confined to the Oberon Plateau with just the occasional, colder shower passing over Blackheath and other high towns over this way. As a result, the snow showers were infrequent but nice when they occured. Surface temperatures never really got below about 1.5C so the snow showers were wet and big flakes at times and frequently returned to sleet and light rain. The Oberon Plateau had heavier snow that was assisted by upslope winds initially and then the higher ground near Shooters Hill and Mt Trickett really helped bring out the best in this system. Not a brilliant system but a very welcome one with some fun weather as a result.
18-7-07, Thursday: This very cold but quite stable event (this far north east) panned out pretty much as expected for the central tablelands. The frontal band moved through last night from about 9pm or so and started producing snow in places like Orange and Oberon. These areas accumulated about 2 to 3cm of snow with higher areas around Shooters Hill on the Oberon Plateau having around 5 to 8cm by the roadside. Blackheath only saw snow flurries from about 10:30pm to a little after midnight with some quite large flakes at times. No noticeable settling occured. Whilst the BoM had potential snow down to 600M or so for the CT, the stable conditions and limited moisture available this far north was never really going to produce much snow outside of the usual spots up higher. I have a lot of respect for the forecasters though at the BoM as they have to make forecasts under significant pressure and do a fine job.
The Sydney weather balloon sounding for this morning is pretty impressive with temperatures at 500hPa of around -32C, -13C at 700hPa and about -2C at 850hPa, the latter 850 hPa reading being roughly the height of Shooters Hill or a bit higher. Those three heights in the atmosphere are the common heights used to determine the coldness of an airmass and those figures are impressive indeed but this far north we had a fast moving, surface high pressure system that soon reduced any chances of prolonged, decent snow by making the lower atmosphere very stable. Add to this, the upper level jetstream was too south west (almost west) and not enough south and was also not very strong. This had the effect of pushing snow showers to our south out to sea, before they reached us. A good, strong southerly jetstream is usually important for decent central tabelands snowfalls as it steers storms from the south towards us and keeps them 'alive' as well by maintaining instability. Still, you can see just how well the ski fields fared via the webcams with such a cold air mass down south, where the instability was greater. NB: Thanks to Laurier Williams from Australian Weather News for the 'on the ground' obs from Shooters Hill in the middle of the night!