Thursday, 16 July 2009

BARRINGTON TOPS SNOW CHASE

From: Barrington Tops, Written by: Grant Burgess

http://raymondterrace.hunterweather.com/

Accompanied by Trevor Burgess (dad)

An unconventional cold outbreak developed from the west & moved east across NSW focussing more toward the northern half of the state. The uniformity of the 500hPa temperatures (around -28°C) across NSW are not often seen.

Williamtown sounding details: Thu 16/07/2009 at 1000hrs

850hPa Temperature        0.4°C

500hPa Temperature     -27.7°C

Thickness                     5373m

Moisture today appeared adequate & I was hopeful of even catching a passing snow shower. On approach, dark towering cumulus clouds with glaciated tops could be seen sitting over the western side of the Barrington Plateau. We passed thru the cloud base at 1100m with the car showing a 5°C temperature & observed our first settled snow just below the Dingo Gate (Moonan Lookout) at 1250m. The temperature here at 1300m was 3°C at 1410hrs. From 1420hrs onwards for about the next 15mins light icy showers of sleet & snow moved in along with thicker fog. Snow cover here was a patchy 1-2cm cover. For the first time I noticed my Telstra NextG mobile had a strong signal at this location.

The car thermometer dropped as low as 0°C on the way to Polblue where it remained till back past the Dingo Gate on descent some 2 hours later. Polblue (1450m) saw a 4-5cm cover with my mobile thermometer varying only between 1.4-1.6°C for the whole time we were there. Icy showers began after 1610hrs & reached a moderate intensity briefly on one occasion. These showers consisted of pure white ice pellets smaller than 2mm in diameter which bounced off our clothing. Upon leaving even noticed nearby static on the AM radio.

Left Polblue at 1655hrs & arrived back at the Dingo Gate at 1720hrs, this 25min drive (usually only 15min) was extremely difficult due to thick fog (visibility below 10m on occasions), the fading light & the poor state of the road conditions at the moment. I actually travelled with my hazard lights flashing for no less than 20min & could not have my headlights on due to the excessive glare off the fog, only my parking & fog lights. We also had several brumbies to contend with near the pine plantation. The heavy fog base was down to 1100m before we ran into another lighter patch ~800m.

Icy precipitation began again just before the Dingo Gate & continued down to an elevation of ~900m where it turned to pure rain. This icy mix consisted of mostly sleet & snow. These light/moderate showers continued on & off all the way back to Gundy.