By Doug Schneider

Good morning from VIR! I awoke to this view from my room at the Lodge - 

There are some isolated showers around this morning, but they likely won't have an impact. Most of the day will be partly to mostly cloudy, with temperatures reaching the mid to upper 80s.

A cold front will be moving across the area from north to south today. Showers and thunderstorms are expected to develop this afternoon, affecting the track starting around 4 pm (+/- 1 hour). The time period with the highest chance of storms is between 4 and 8 pm. Lightning and gusty winds will be the main threats from these storms, and rainfall may be heavy. Rain amounts are likely to be between a quarter and a half inch.

For Saturday, with the front located across central North Carolina and continuing to push south, there will be just a 20% chance of light showers in the morning. It will be mostly cloudy and cool through the day, with a high in the lower 70s. Winds will be from the northeast at 5-10 mph.

Mostly cloudy and cool conditions will continue on Sunday as high pressure to the north extends over the area.  Highs will be in the upper 70s, with a northeast wind at 5-10 mph.

By Doug Schneider

The good news with today's forecast update is that the models are starting to agree on the timing and position of a cold front south of St. Louis, which gives me more confidence in this forecast. 

A cold front is expected to cross through St. Louis on Thursday night. It will be close enough to the track and with enough uncertainty about its speed that I will keep a small chance of rain in the forecast for Friday morning. But since on-track activity does not start until the afternoon, no impact is expected. Behind the front, drier air will be building in from the north through the day, and with mostly cloudy skies, high temperatures will be quite comfortable in the lower 80s. 

As the front is expected to stall across southern Missouri on Saturday and high pressure over the Great Lakes region will extend across Illinois, Sunday will stay dry. Previous model runs had shown a weak disturbance approaching Saturday, but that no longer appears to be the case. With more sunshine expected, highs on Saturday will reach the mid 80s, but humidity will be comfortably low. Temperatures during the race will be in the 75 to 80 range. 

I will be traveling to VIR tomorrow for the IMSA race this weekend, and Friday may be a busy day of providing weather support to the track, so I may not get to update this forecast until Friday night. 

By Doug Schneider

The models are coming into better agreement on their projections for rain chances at VIR this weekend, which increases my confidence in this forecast compared to Monday. Unfortunately, they are not moving in the direction I had hoped for, as the chances of rain appear higher for Friday and Saturday morning. 

A cold front will be moving from north to south across Virginia on Friday. Showers and thunderstorms will be numerous along this front as it approaches VIR late in the day. With good instability present and plenty of moisture to work with, I have raised the chance of rain on Friday to 80%. Thunderstorms will be a concern, and some of them could be strong, producing gusty winds,frequent lightning, and heavy rainfall. Rainfall amounts are expected to be between a quarter and a half inch. While there will be a chance of rain at any time of the day, the afternoon sessions are most likely to be impacted, including the Michelin Pilot Challenge qualifying. 

Rain showers are likely to persist through Friday night as the front moves through the area. If you're camping at the track Friday night, be prepared for wet conditions. Although the front will be south of VIR Saturday morning, there could still be some scattered showers around in the morning. These showers will have less impact on activities than Friday's storms. There is a much lower chance of lightning and heavy rain. If rain occurs on Saturday, I expect it to be fairly light, less than a tenth of an inch, which would not have much impact. Behind the front, a north wind will bring cooler air, and with mostly cloudy skies, highs are expected to be in the upper 70s to near 80. 

The front is expected be located across central North Carolina on Sunday, and the rain associated with it should remain far enough south of VIR to keep any chance of rain out of the forecast. Weather for the main event on Sunday should be quite nice, with partly sunny skies and high temperatures around 80. 

I plan on posting the next update on Friday. However, I will be at the track providing weather support, and with the active weather expected, I may not have time to put a forecast together until the evening, or possibly Saturday morning.

By Doug Schneider

A programming note - Scott was originally scheduled to make this forecast, but due to a busy week at his real job, I'll be pulling double duty with IMSA at VIR and IndyCar at Gateway. Normally we would also have the forecast for the IGTC race at Suzuka, but Stephen is traveling out of the country this weekend, so that race forecast has been dropped.

A cold front is expected to move north to south across the St. Louis area on Thursday night. The front ix expected to be positioned south of the area by the time on-track activities start on Friday afternoon. However, it won't be very far away, and an upper level disturbance is expected to draw moisture northward over the front on Friday afternoon. As a result, scattered showers and possibly a thunderstorm will be possible in the St. Louis area. It appears that the afternoon hours will have the best chance of rain, which could impact the qualifying sessions for IndyCar, Indy Lights, and Pro 2000. With scattered coverage, they could be hit-and-miss, but I'd put the chance of rain at the track at 40% right now. 

The front to the south is not expected to move much through Sunday, but a little drier and more stable air may be able to build into the St. Louis area on Saturday as high pressure tracks east across the Great Lakes. With the front still being nearby, I don't feel confident enough to keep Saturday entirely dry, but the chance of rain is low, just 20%. If there is an isolated shower Saturday, it would probably be in the afternoon during the Pro 2000 and Indy Lights races. I expect that the IndyCar race in the evening will remain dry. 

One piece of good news in this forecast is that temperatures will be very pleasant through the event. Afternoon high temperatures will be in the lower to middle 80s, and temperatures during Saturday night's race will be in the 75 to 80 range. 

​I expect that there will be some changes to this forecast as we get closer to the weekend and the details come into better focus, so stay tuned.

By Doug Schneider

A cold front is expected to bring some showers and thunderstorms to the Virginia/North Carolina border region on Thursday, but there is a lot of uncertainty about what happens after Thursday as the models do not agree on where the front will be located as on-track activities begin at VIR.

​The chance of rain at VIR is highest on Thursday as a cold front approaches from the north. Showers and thunderstorms are likely Thursday afternoon, with the chance of rain around 60%. 

There are a couple different scenarios about how fast this front will move through southern Virginia, which makes this forecast uncertain. The GFS model is quick to push the front through and bring in dry air behind it. It shows the front moving south of VIR on Thursday night, and brings in cooler and drier air on Friday. This scenario would keep Friday through Sunday rain-free. 

The ECMWF (Euro) model is much slower with the southward movement of the front. It does not take it south of VIR until late Friday night or Saturday morning. This scenario would keep a chance of rain going through Friday and into Saturday. 

With such as big timing difference, my forecast confidence is low, but I'm going to take a middle-of-the-road approach. I think the front will be close enough to VIR to warrant a chance of showers and thunderstorms on Friday, then move far enough south to keep rain out of the forecast for Saturday.

The good news in this forecast is that the main event on Sunday is likely to be dry. Since the models are in agreement for that day, my confidence in Sunday staying dry is moderate to high.

​Temperatures and humidity levels should drop a little behind the front, and with partial cloud cover and a northeast wind, Saturday and Sunday should be pleasant days to spend at the track with highs in the mid 80s. Not bad for late August in southern Virginia.

I'll be at the track so I'm really hoping the dry scenario works out. Check back through the week for updates.