By: Stephen McCoy

An area of low pressure at the surface is currently moving through Scandinavia, with an area of high pressure over the north Atlantic, west of Ireland. Over the next few days, the low is expected to progress eastward into western Russia, however a second area of lower pressure will spin off from this main low and remain mostly stationary over the southernmost extend of the border of Norway and Sweden. The aforementioned area of high pressure is expected to weaken midweek as it moves into the Bay of Biscay. The clockwise flow around the high, coupled with the counterclockwise motion around the low will result in cooler temperatures over north-central France on Wednesday as winds will be directed from the northwest. Conditions will be mostly clear, though with some lower level cloud cover in the afternoon as low level winds are also expected from the north. A few isolated showers may be possible due to the incoming low level moisture from the English Channel, but will be fairly light if any occurs.

Thursday's temperatures will be similar to Wednesday as the area of high pressure moves over central France. Stagnant air during the morning, along with higher values of relative humidity may result in patchy fog that could last through the mid-morning. Otherwise, conditions will be consistent with the previous day, albeit with a change in wind direction to the southwest.

This change in wind direction comes due to a stronger surface low pressure system approaching the British Isles on Thursday, with a front extending to the south. Winds ahead of the front will be from the south to southwest, causing warmer air to enter the region, which will result in warmer lows Friday morning. Much like the system earlier in the week, this surface low is expected to slow dramatically, remaining stationary over the United Kingdom through the remainder of the weekend. The counterclockwise flow around the system will bring consistent afternoon temperatures around 19 C (65 F). But with increased moisture moving in from the Bay of Biscay, cloudy conditions are anticipated to persist, along with the potential for showers moving through the region each day; current guidance suggests daily rainfall totals of 3-5 millimeters (0.1-0.2 inches).

By Doug Schneider

The end of 2023 is upon us, and that means it's time for our annual gallery of the best photos combining our two favorite things - weather and racing. 2023 was a great season for race fans, with tons of action and excitement in IMSA, IndyCar, F1, and SRO World Challenge. We can't wait for the 2024 season to start, and we will be back in a few weeks with the forecast for the Roar Before the 24 at Daytona. You can see our full schedule of race forecasts in the link at the top of the page.

We are making a couple changes for next year. Scott Martin is stepping down from our team due to a new job and time commitments. Scott helped me start Racecast Weather 9 years ago, and he will be greatly missed. As a result, we will not be forecasting for SRO World Challenge America races. However, we will continue to have forecast for SRO's IGTC races. Harris will continue to provide you with forecast for Formula One. Stephen will return and focus on forecasts for the IndyCar season. And I will be back with forecasts for all IMSA events.

​We wish you a Merry Christmas and a Happy New Year. Thanks for following!

By Doug Schneider

Rain will likely be a factor in the 24 Hours of Le Mans, especially around the start of the race on Saturday. 

The weather pattern over western Europe continues to show a low pressure system off the west coast of France, and this will change little over the weekend. This morning, rain showers are occurring along the west coast of France, and through the day, these showers will slowly advance toward the west. Showers are likely in Le Mans by the afternoon. Tonight, the showers are expected to taper off, then return by Saturday morning. Saturday looks like it will be a rather wet day, with periods of rain possible at any time. It does not appear to be a heavy rain, so I expect that the racing will be able to be held as scheduled. But it will make for a challenge for the teams and drivers, especially at the start. Rain amounts on Saturday are expected to be between a quarter and a half inch, or between 6 and 12 mm.

The chance of rain will decrease Saturday night, and I expect that most of Sunday will be dry. However, there is a chance that some showers and thunderstorms will develop in the area during the afternoon. The chance of impacts on the race appear low at this time, but there is some disagreement among the models on where the showers will develop. Hopefully the race can end under good weather conditions, but we will have to keep an eye on the radar.

By Doug Schneider

The pattern across western Europe during the second half of the week will have high pressure over England and the North Sea, with a low pressure system in the eastern Atlantic, off the Iberian Peninsula. As Le Mans practice sessions begin, the weather will be sunny and warm on Wednesday and Thursday, thanks to the high pressure system being dominant. Through the weekend, this pattern will shift slowly east, so that the high loses its grip and the low pressure system spreads moisture into France. Showers are likely to arrive at Le Mans during the afternoon and evening hours on Friday. Showers will continue to be in the area through Saturday. The good news is that this does not look like a very heavy rain. I expect that it will be light enough to allow for the on-track sessions to be held, for the most part. Interruptions should be minimal, but wet tires will likely be needed. On Sunday, there is just a small chance of showers, and I expect that the second half of the race will mostly be dry. 

​Check back later in the week for updates.

By Doug Schneider

Every year around Le Mans, I always hear the phrase, "It always rains at Le Mans". Well, this year will be the exception. There are some isolated showers around the track on Wednesday, but dry weather is expected for the rest of the event. Every day will be mostly sunny, with comfortable temperatures and light winds as a large high pressure system extends over northern France. It doesn't get any better than this for weather at Le Mans.

The changes to this forecast from my previous forecast were pretty minor, with only small downward changes to temperatures, and the slight chance of rain Sunday has been removed. 

By Doug Schneider

The weather looks great for this year's edition of the 24 Hours of Le Mans. 

A cold front will be moving through northern France on Tuesday night and Wednesday morning, which will result in showers around Le Mans. Most of these showers will occur in the morning, with conditions improving through the day. If some showers do linger later in the day, I expect that they will be light and impacts will be minimal. 

Behind the front, high pressure will build over northern France and provide nice weather through Saturday at least. Temperatures will be very comfortable, with a warming trend through the week. 

The high pressure ridge weakens a little on Sunday, which may allow for a few showers to develop on Sunday, mainly in the afternoon. This is still a way out, so there is still some uncertainty about the rain chance, but it appears to be low at this time, with no significant impacts expected.

Check back for updates through the week. 

By Doug Schneider

​Click images to enlarge

The forecast for Le Mans has been really tough this year, as the models have been flip-flopping regarding the timing of a low pressure system that will cross northern France and England. The good news is that they seem to be coming into better agreement, and showing better consistency. The most likely time period for showers at the track appears to be from late afternoon on Saturday into the evening. There could still be some light showers or sprinkles that continue overnight and into Sunday morning, but those should be light. Bottom line, I think the biggest potential impacts from rain could be around the start of the race. Temperatures will be on the cool side due to the extensive cloud cover from this system and behind it on Saturday and Sunday. 

by Doug Schneider

​Click images to enlarge

The models have taken a pretty big shift over the past few days, and are now showing a good chance of rain during the race.

The days leading up to the race should have good weather for practice, qualifying, and support races. Temperatures will be comfortable for Wednesday through Friday, gradually climbing from the lower to mid 70s F to lower 80s F, under partly cloudy skies each day. 

There is agreement among the models that a low pressure system will track from the northern Atlantic to the English Channel over the weekend. This should bring a chance of rain to Le Mans starting late Saturday afternoon. The system will be slow-moving, so the chance of rain will continue Saturday night and Sunday. At this time, it is nearly impossible to pin down the timing more precisely than that. Timing should become more clear later in the week. Temperatures should be warm at the start of the race Saturday afternoon, then become cooler on Sunday behind a cold front.