First of all, I want to apologize to the sports car fans for leaving out the graphics for the Blancpain GT World Challenge America series for this weekend's event at St. Petersburg. It's been a tough week in the weather office for me as we in Central Alabama are recovering from severe storms that swept through the area last weekend and gearing up for the potential of more severe storms this weekend.

The good news for St. Petersburg is that conditions probably could not be any better as we'll see plenty of sunshine with just a few passing clouds on both days. Highs will be approaching 80 degrees with morning lows starting off in the mid to upper 60s. Wind on both days will start off out of the southeast at 5-10 MPH but will eventually shift out of the southwest by the afternoon hours.

This will be the last forecast update for this event unless there are drastic changes that need to be made to the forecast. No radar on the site this weekend as well as I'll be utilizing it for severe weather coverage in Central Alabama.

By Doug Schneider

The timing of the rain chances along a cold front has shifted a little later with this forecast update, but any rain that falls is not expected to have an impact on the racing activities.

The models have started to come into better agreement on the timing of rain being mainly on Friday night. I expect that rain won't fall in Toronto until after sunset, well after the end of any on-track activity on Friday. With the later arrival time for rain chances, Friday should have more sun and temperatures should reach the mid 80s. As I mentioned in the previous forecast, any rain is expected to be pretty light and scattered, and that is still the case. The front should move through the area early Saturday morning, and a light shower or sprinkle could be possible after sunrise. As a result, I have just a slight chance of rain mentioned for Saturday morning, with no impact expected on the racing. If rain does fall on Friday night and Saturday morning, I expect it will be around a tenth of an inch or less.

High pressure through the lower and mid levels of the atmosphere will build over the Great Lakes region for Sunday, which will bring warm temperatures and plenty of sunshine.Highs on Sunday afternoon are still expected to reach the upper 80s, with light winds.

By Doug Schneider

IndyCar has had a string of races with great weather, and it looks like that will continue this weekend on the streets of Toronto. There may be some showers and storms around on Friday, but the weather looks nice for the rest of the event.

On Thursday, high pressure from the surface through the midlevels will be over the Great Lakes region, drifting toward the southeast, as a low pressure trough and cold front move across the Northern Plains and south-central Canada. This approaching system will bring a chance of rain to the Toronto area on Friday and Friday night. It does not appear to be a very strong system, and the rain probably won't be heavy or last for very long, but there are some timing uncertainties this far out in the forecast. It could arrive as early as Friday morning or as late as Friday evening. Later updates will pin down the timing a little more.

Another high pressure ridge builds in behind the departing trough, and will provide mostly sunny and warm conditions for Saturday and Sunday. Highs both days will be in the mid to upper 80s. One thing to keep an eye on will be if the Friday/Friday night system slows down even more than the models currently show, and rain continues into Saturday morning. I think that is unlikely at this point, so I am keeping Saturday completely dry with this initial forecast.

By: Stephen McCoy

The warm front mentioned in the previous discussions will continue to be centered horizontally east-to-west over the Midwest. This is expected to set up a very strong temperature gradient over central Indiana, having a 20F degree difference in temperature in about 50 miles. Thankfully, Indianapolis Motor Speedway is expected to be on the warmer side of the warm front. During the day, the front is expected to push slowly southward and will bring a chance for isolated thunderstorms to central Indiana during the afternoon. A small shortwave trough in the upper atmosphere and winds from the south and southwest in the lower levels will help contribute to this chance. The Storm Prediction Center has Indianapolis under a Slight Risk (level 2 of 5) for severe storms, but this could change depending on the exact location of the warm front. So, be sure to stay weather aware if at the track, since these pop-up storms could be hit-or-miss. Expect winds from the south to southwest around 10-15 mph with gusts around 25 mph.

By Stephen McCoy

If you are at the track either day, it might be a good idea to bring an umbrella just in case as both Friday and Saturday have a chance of isolated to scattered rain.

Initial winds in the morning will be out of the northeast and east, bringing some cooler temperatures before swinging to the south and southwest with the approach from a warm front. Surface winds and winds in the lower portion of the atmosphere are expected to align in the same direction, causing winds around 15-20 mph with some stronger gusts approaching 25-30 mph. The warm front is expected to move through central Indiana mid-day, causing rain to the North and West of Indianapolis. However, depending on exact placement of the front in the afternoon and evening, coupled with daytime heating, it could bring a few isolated showers into central Indiana and has a low chance of affecting on track activities.

With the passage of the warm front, expect warmer temperatures in the upper 60’s in the morning. As the day progresses, winds continuing from the south and southwest will bring temperatures into the upper 70’s. Wind speeds are expected to remain constant through the forecast period at around 10-15 mph with gusts at 25-30 mph. The Storm Prediction Center currently has a Marginal Risk of storms (level 1 of 5) stretching from Iowa through West Virginia and includes much of central Indiana. There is a chance of scattered thunderstorms that could affect the races held in the early afternoon. Look for a more definitive outlook in the next update.