By Doug Schneider

A cold front moving across Florida will bring a line of showers and thunderstorms to Daytona tomorrow. Over the past few days, the trend has been toward a later arrival of the showers, and now I expect that the chance of rain will fall mainly between 11 AM and 3 PM. During this time, showers may produce a tenth to a quarter inch of rain, as well as cloud-to-ground lightning. The good news is that the line should move through fairly quickly - it won't last all of the 4 hours of the time frame, but that is the window when I expect the showers to move through. I expect that the rain will last for about an hour, maybe two at most. The IMSA Prototype Challenge race is the event that is most likely to be affected. There may be a stoppage during the race for lightning in the area or brief heavy rain.

On Sunday, the main weather impact will be much cooler temperatures. Low temperatures in the morning will only be in the mid 40s, with a high struggling to reach 60 in the afternoon. It will be a little breezy, with a northwest wind at 10 to 15 mph, but at least there will be plenty of sunshine.

By Doug Schneider

The timing of a cold front has changed since Monday's forecast, shifting the chance of rain out of Friday and into Saturday. 

Friday at the Roar will be a sunny and warm day, with high temperatures reaching the mid 80s. Clouds will start to increase late in the day, and rain will likely begin to fall overnight. A cold front will move across the area on Saturday morning, and there could be a few thunderstorms with it. The front appears to move through fairly quickly, so while there could be some delays or cancellations in the practice sessions on Saturday morning, there should be enough time to get plenty of practice done through the afternoon. Rainfall is not expected to be heavy, with just a tenth to a quarter inch expected. Saturday will be a little breezy, with wind gusts between 20 and 25 mph.

Behind the front, temperatures will be much cooler. Lows on Sunday morning will only be in the mid 40s, with a high on Sunday in the lower 60s, despite abundant sunshine. 

By Doug Schneider

A cold front is expected to move across the Daytona area and bring showers to the Speedway on Friday and Friday night, but the good news is that the timing of most of the rain should allow for very little impact on the on-track activities. 

The Roar will open with warm temperatures and a good southwest breeze on Friday. Through the day, clouds will be increasing as a deep upper level trough and its associated cold front move across the Plains to the eastern United States. Ahead of this front, some scattered showers may develop around Daytona on Friday afternoon. I expect that only the late day practice session will have a chance of rain, and any rain that occurs will likely be light. The main band of showers with the cold front is not expected to move across Daytona until after dark on Friday night. 

By the start of practice on Saturday morning, the cold front should be east of the Speedway, and clouds will gradually be clearing out. The track may be wet in the morning, but it should dry out quickly with clearing skies and a bit of wind. Temperatures will be cooler compared to Friday, but still quite pleasant in the lower 70s. Winds will shift to the west and still be a little breezy at 10 to 15 mph. 

High pressure building over the area will bring a northwest winds and cooler temperatures for Sunday, with morning lows in the upper 40s and afternoon highs in the mid 60s. Still, there will be plenty of sunshine all day, along with low humidity. 

Over the past few days, the models have been in pretty good agreement on this pattern, and have not changed much from run to run, so my confidence in this forecast panning out is fairly high. Check back through the week for updates.

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

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.