By: Stephen McCoy
Only minimal changes were made to the forecast in this update for the California 8 Hours, most notably a lower chance for precipitation on Thursday. A slight chance for scattered showers is still present, but confidence is waning. Of the major computer models that we use for our forecasts, the Euro now stands alone when expressing rain during the day. However, the iterations of the model over the past day have yielded the same result, albeit indicating rain occurring more towards mid-day, which is too significant of a result to fully ignore. Should the Euro be correct, scattered showers will move through the region around noon from the north/northwest, though the model estimates precipitation rates around 1/100th of an inch per hour which would provide more of a nuisance than a major impact for the sessions on Thursday. The Euro is also indicating precipitation near the same magnitude Thursday night into Friday, but this would have no impacts to Friday's sessions.
By: Stephen McCoy
Some pleasant early-spring weather is in store for the California 8 Hours, but only after dealing with a slight chance for scattered showers on Thursday morning.
A trough in the upper levels over the Pacific Ocean is expected to move eastward towards the continental U.S. early this week. This trough will lead to the development of two surface low pressure systems in the Pacific off the west coast. The first system is expected to remain off the coast, moving northward into the mid-week. The cold front from this system will impact the region Monday and Tuesday, bringing high chances for precipitation to northern California. The second low pressure system is expected to be slightly stronger, with the cold front moving through the region on Wednesday, extending overnight into early Thursday. Much of the precipitation will exist along the front, however some lingering moisture from southwesterly flow in the lower levels of the atmosphere could threaten some of the earlier sessions on Thursday morning.
Winds Thursday morning will initially be from the south/southeast off the Santa Lucia Mountain Range before shifting to the west/northwest as the low pressure system moves north along the coast. Low level winds also from the west/northwest will cause some breezy conditions with gusts approaching 15 mph. The wind direction is expected to bring some moisture off Monterey Bay, resulting in partly cloudy conditions mid-day onward, though dry conditions aloft will decrease precipitation chances for Thursday afternoon and evening.
The rest of the weekend is expected to remain dry, with conditions on Friday and Saturday very similar to each other. An area of high pressure will build in behind the cold front on Wednesday/Thursday and move north up the coast during the weekend, keeping winds consistently from the north/northwest other than the mornings, where winds will again come from the south/southeast off the Santa Lucia Mountain Range. Winds on Friday are expected to orient in a more northwesterly direction which will bring some moisture off the bay and resulting in some partly cloudy conditions in the low levels. Saturday's winds are expected more from the north, resulting in fewer low level clouds as the winds traverse over more land than the water. However, an upper level ridge is expected to set up over the Pacific Ocean, funneling moisture from the equator to northern California. This could cause some upper level partly cloudy conditions to develop during the day on Saturday, but should have no impact on the race.
By Doug Schneider
The chance of a shower or thunderstorm occurring in the Bathurst area Saturday afternoon looks a little bit higher with the latest model runs. It is still a fairly low chance, just 30%, and if it does occur, I don't expect that it will have a big impact on the racing. Any showers in the area should produce just light and brief rainfall. The chance of lightning in the area is even lower, maybe around 10%, but it can't be ruled out entirely. The timing of any potential showers appears to be around or after 4 pm local time, which may affect the Combined Sedans race and the Top 10 Shootout.
Radar coverage is rather sparse for inland parts of New South Wales, but here's a link to a radar near Sydney.
The weather for the race continues to look dry and warmer, with temperatures at start time in the mid/upper teens C or lower 60s F. With a good amount of sunshine expected, high temperatures will reach the lower 30s C or upper 80s F by the end of the race.
By Doug Schneider
Today's forecast update for the Bathurst 12 Hour has a few small changes in it compared to my last forecast, but overall, the weather continues to look great for racing.
The expected weather pattern across southern Australia hasn't changed significantly, with a large high pressure area off the southern coast expected to drift eastward through the weekend. This high brings cooler and drier air to New South Wales on Friday. I did raise temperatures a couple degrees for Friday and Saturday from my initial forecast.
The main change with the update was to add a mention of a possible afternoon shower on Saturday, as it appears that there will be just enough instability to allow for some showers to pop up. The best chance of showers will be over the higher terrain of the Blue Mountains, east of Bathurst. With the prevailing wind flow coming from the east, some of these showers that develop over the mountains could push west toward Bathurst late in the day. As you can see in the forecast, the chance of a shower happening at the track is low, only 20%.
The weather for the race looks great, with comfortable temperatures at the start in the upper teens C or lower 60s F. High temperatures during the race will rise into the lower 30s C or upper 80s F. There will be some cloud cover developing in the afternoon hours, but no rain is expected.
By Doug Schneider
The first round of the Intercontinental GT Challenge takes place this weekend at the awesome and beautiful Mount Panorama Circuit near Bathurst, Australia. The weather for the entire event looks great.
Thursday will open with warm temperatures in the mid 30s C/ mid 90s F. Then a cold front will pass through the area Thursday night, which will shift winds around to the south. There will not be enough moisture with the front to produce any precipitation.
High pressure off the southern Australia coast will be building into New South Wales on Friday, and with it will come cooler temperatures and a southeast wind. This high will be drifting east across Tasmania and toward New Zealand through the weekend. As it does, winds will shift back around to a northerly direction, bringing a gradual warming trend each day. By Sunday afternoon for the end of the race, temperatures will be back over 30 C.
One thing to keep an eye on will be the potential for afternoon showers to pop up on Sunday. At this time it seems unlikely, but with warming temperatures and a little more moisture, it can't be ruled out entirely. I'm going with a dry forecast for now, but stay tuned for updates later in the week.
Doug Schneider, Scott Martin, and Stephen McCoy are race fans and meteorologists dedicated to providing accurate forecasts and timely weather updates at racing venues around the world. We forecast for IndyCar, Indy Lights, Pro Mazda, USF2000, IMSA, Blancpain World Challenge America, and World Endurance Championship, as well as major SCCA and NASA events.