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.

There is really not much change in the forecast for the season finale for the Blancpain GT World Challenge America series at Las Vegas. Skies will be sunny to mostly sunny throughout the entire event weekend with temperatures starting off rather warm on Thursday and becoming more mild by Sunday. Winds will be the only weather issue we'll have to deal with as we could see gusts up to 30 MPH on Thursday, 20 MPH on Friday, and 25 MPH on Sunday. With the wind, you may need a light jacked throughout the day on Friday and Sunday.

You probably couldn't ask for a better forecast to end off the racing season than what looks to happen this week at Las Vegas Motor Speedway. While Friday and Saturday look nearly picture perfect with mild temperatures and plenty of sunshine, we'll have to contend with some gusty winds on the first day of practice on Thursday.

Winds will be increasing through the morning hours and will be averaging around 5-15 MPH out of the south, but gusts up to 25-30 MPH will be possible during the late morning and into the afternoon hours. Other than the wind, no weather problems should occur as skies will be sunny with no rain expected. Temperatures start off in the lower 60s at 8:00 am and warm into the mid-80s for the afternoon high.

Friday and Saturday will nearly be identical in the weather department... There will be plenty of sunshine on both days with only a few passing clouds. Once again no rain in the forecast and afternoon highs will be mild. While both days will top out in the upper 70s, Friday will start off a little warmer near 60 degrees at 8:00 am with Saturday starting off in the mid-50s.

Sunday looks to be a great day at the track as well as skies will be sunny with maybe a cloud or two, but we'll stay dry and mild. Temperatures start off in the mid-50s at 8:00 am and top out in the mid-70s. Winds will be out of the north at 6-12 MPH.

By Doug Schneider

There has been a pretty big shift in the forecast for Sunday at VIR, and it now appears that there will be a good chance of seeing rain during the day. 

A cold front is expected to move into the area Saturday night, which is in line with the previous forecast thinking. However, the models are now showing this front slowing down and stalling as it moves into the Piedmont of NC and VA. It is expected to be located just southeast of VIR on Sunday. Meanwhile, an upper level disturbance will be approaching, and its interaction with this front will produce some showers in the area. Rain is possible any time of the day on Sunday, but it appears that the best chance of rain will come in the afternoon. Rain amounts in the neighborhood of a tenth of an inch can be expected. Since this isn't expected to be a heavy rainfall, and no lightning is expected, I kept the impact as low.

By: Stephen McCoy

A cold front moving through the region on Saturday will bring more cloudy conditions than the rest of the weekend, with slightly cooler temperatures. Surface winds are expected from the west to southwest during the morning, but will shift to the west to northwest behind the front. Temperatures will be about the same as the previous few days, but will cool behind the front; temps by the end of the race will be in the low to mid 60's. There is a slight chance for isolated showers ahead of the front near the early to mid afternoon; model output suggests maximum totals during the race around a few hundredths of an inch should precipitation occur.