By: Stephen McCoy

Conditions for the Bathurst 12 Hour remain mostly unchanged except for Sunday, which shows an increase in precipitation chances as the result of a cold front moving through the region. Much like in the initial forecast, a surface high pressure system is expected to sit stationary over the Pacific Ocean off the West coast of Australia. As it brings in warmer air from the North/Northwest, an upper level trough over the New South Wales territory will keep the heat trapped closer to the surface, resulting in temperatures well into the 30's C, 90's F on Friday and Saturday. Where this forecast update differs with the initial is that model guidance now suggests an upper level trough will move to the south of the continent, allowing a low pressure system to form at the surface, moving eastward Saturday into Sunday. A cold front will extend to the Northwest from the system, and is anticipated to move through the NSW region in the early to mid-afternoon on Sunday, bringing with it a chance for scattered showers with some thunderstorms possible. Maximum temperatures reflect the frontal passage, being a few degrees cooler than the rest of the weekend.

By: Stephen McCoy

A fairly straight-forward forecast for the Bathurst 12 Hours this weekend: lots of sun and hot temperatures each day. An upper-level ridge will sit over the NSW region with an accompanying surface high pressure system present just off the coast. North to northwesterly winds will bring warmer temperatures to the region, while the ridge will keep the heat trapped nearer to the surface. Northeasterly winds during the morning on Friday will bring in a slight amount of moisture off the Pacific Ocean and could result in some fog, but will any amount will disappear after sunrise. Slight amounts of smoke/haze are possible for the remainder of Friday from bushfires to the south, however the conditions are unlikely to continue for the rest of the weekend. Light cloud cover is expected for Saturday and Sunday as a result of mid level winds from the east, and will increase towards Sunday evening, but overall conditions will remain mostly sunny.

By Doug Schneider

Each year at Racecast Weather, we collect photos through the year of our two favorite things - weather and race cars - and pick the best to be featured in a final post to close out the year. Thanks to the extremely talented photographers (and not so talented, like myself) who took these photos - credit for each pops up when you hover over each image. Click on each image to view a larger size.

Thanks for following our forecasts through 2019, and Scott, Stephen, and I hope you have a very happy Christmas season. We'll see you again on December 30 with the forecast for the Roar Before the 24 in January.

By: Stephen McCoy

Springtime conditions are in full swing in South Africa this weekend for the Kyalami 9 Hours. The race weekend will kick off with some lingering showers possible during the early morning on Thursday after showers and thunderstorms are present on Wednesday as an upper level trough moves eastward over the region. As upper level winds return to zonal flow, an area of high pressure is expected to build in at the surface, diminishing chances for precipitation during the remainder of Thursday; some moisture will remain in the lower levels, causing partly to mostly cloudy conditions.

Conditions will wane overnight with mostly clear skies anticipated for Friday morning. Warming air temperatures and dew point temperatures near 16°C (60°F) will allow CAPE values in the afternoon to approach 1000 J/kg, providing an environment for possible thunderstorm development. Similar conditions are likely for Sunday, and may bring a chance for isolated showers in the early afternoon once again.

By: Stephen McCoy

The start of the TOTAL 24 Hours of Spa currently looks to have the largest chance for precipitation for the race. A few outlier models indicate that precipitation may start in the morning, however model consensus supports the idea of the main showers beginning in the early afternoon during the build-up to the green flag. CAPE values for the start of the race are projected between 500-800 J/kg, which speaking from an American viewpoint is a small amount, however from a European standpoint it could be a moderate amount and enough to kick of thunderstorms in the mid-to-late afternoon. As Sunday approaches, thunderstorm potential should decrease as the convective energy will be used up by storms on Saturday. Fog may become an issue near sunrise due to the air at the surface becoming saturated either by precipitation or by ground evaporation. Precipitation chances will begin to trail off towards Sunday afternoon, though the high resolution models indicate that there may still be some isolated showers in the area; forthcoming runs could place one of these showers directly over the track, but for this forecast conditions remain mostly dry.