By Scott Martin.

A welcome back to Phoenix International Raceway for the Verizon Indycar Series, and the Indy Lights Series will be joining them on this trip out to the Southwest. Great weather is in store for the action at the track, and I do not believe that there will be any complaining. There are two things to expect during this weekend: winds will be shifting a lot during both days, and there is no rain in the forecast at all.

FRIDAY
Action is planned to start at 9AM with the 1st practice session for the Indy Lights series. Skies will be sunny and temperatures will be in the lower 60s. By the time the Verizon Indycar Series gets the green flag at 10AM for the start of their 1st practice session, it will have warmed into the upper 60s to near 70, and will reach the lower to mid 70s by the end at 11:15AM. Winds will start off out of the north-northeast and may shift a little during the morning to out of the ENE.

At 1PM, temperatures will have climbed into the upper 70s to near 80, and winds will have started their shift as expected and will be out of the north for the start of the 2nd practice session for the Indy Lights series. Qualifying for the Verizon Indycar Series is up next starting at 2PM, and temperatures will have reached the lower 80s with winds now out of the northwest, and should be out of the west completely by the time the last attempt is finished.

Temperatures will start to fall very slowly after that and will be in the upper 70s to near 80 when the Indy Lights series takes to the track for their qualifying runs, and the mid 70s by the time the final practice session is finished for the Verizon Indycar Series is over at 6:45PM.

SATURDAY
Temperatures will be in the mid 60s, and skies will be sunny at 9AM on race day. No track activity is scheduled until 1:25PM, when the Indy Lights series gets the green flag for their 90-lap race. Temperatures will be in the lower 80s by that time, with winds already starting their expected shift from the east during the morning hours to out of the south. By the time the checkered flag falls at approximately 2:15PM, it will have reached the middle 80s and winds out of the south-southwest.

By the time the green flag falls for the Verizon Indycar Series at 6:15PM, temperatures will still be hanging around the lower to mid 80s and winds will then be out of the west-northwest. Temperatures are expected to fall into the lower to mid 70s by the time the checkered flag falls at the expected finish time of approximately 8:30PM. Winds will be out of the northwest at that time.

There will be no radar coverage for this week's events due to possible severe weather expected for my neck of the woods (Alabama), and I will need it to help out with coverage. I will have updates on our social media feeds and on the blog throughout the week. Have a great day.

By Doug Schneider

The forecast for Sebring worked out really well, with the rain on race day predicted the Sunday before the race with a 50% PoP. Friday ended up being dry, but I had only a low chance PoP in the forecast a few days earlier. Forecast high temperatures were never off by more than 5 degrees. The timing of the arrival of the rain on Saturday was forecast pretty well, as my Thursday forecast update mentioned that Saturday afternoon and evening would have the best chances of rain. The race day forecast targeted the arrival of the main area of heavy rain and lightning between 1 and 2 pm, which verified well. A brief shower arrived around 12:30, with the first lightning strike within 8 miles occurring around 12:50, with the main area of storms that stopped the race arriving around 2 pm. Forecasting rainfall amounts in Florida is always a challenge due to the often hit-or-miss nature of the thunderstorms and heavy rain, and amounts can vary wildly over short distances. I was expecting somewhere between a quarter and a half inch of rain, with more possible within stronger storms, and there ended up being 0.74" at a nearby observation site. Some other sites a little farther from the track got over one inch.

The Storm Prediction Center issued a Severe Thunderstorm Watch near Sebring at 1:15 pm, mentioning a potential threat of damaging wind gusts and large hail. While the highest gust I saw at nearby observation sites was around 20 mph, there was some wind damage east of Lake Okeechobee, and even a tornado near Fort Lauderdale. Thankfully, it sounds like everyone at the track was safe and there was no significant damage.

I applaud IMSA for doing their part in keeping the drivers, teams, and track marshals safe from the hazardous weather. They red flagged the race before the frequent lightning arrived at the track. The TV crews were brought down from their scaffolding as soon as lightning was observed nearby. However, it sounds like safety efforts for the fans were lacking in some respects.

I asked some fans who were at the race how they were informed of the approaching weather and the need to take shelter. I received mixed responses. Katie Mech said she was only notified by a text message from a friend. Michael Goodwin said he was notified through the Radio Le Mans broadcast, but not through the PA system. Charley Robertson was notified by the Corvette Car Corral. The fans who replied to me via Facebook mentioned that they were well informed of the situation by PA announcements and the radio broadcast. Others were notified by police officers of the approaching storms (see comment on this post). So it seems that some fans got a message from the track officials, but others did not. Vickie Miller told me that the PA speakers at the track are few and far between, and often cannot be heard when cars are on track. Both Katie and Vickie said that there were no messages on the video screens to alert fans to seek shelter - only a weather map was displayed. And police officers can't reach every person. So whether the message was heard probably depended on where fans were located and whether they were listening to the radio broadcast at the time. Vickie summed up the PA message that she heard this way:

​I noticed that there was one Tweet sent from Sebring Raceway that mentioned the hazardous weather: 

This tweet was sent more than half an hour after the Severe Thunderstorm Watch was issued, and about one hour after the first lightning strike occurred within 8 miles of the track. 

From the information I've gathered, the track could have done a better job of communicating the threat to the fans and keeping them informed. There's no excuse for the lack of a message on video screens. A video message is important as the PA system often can't be heard over the sound of the cars. In addition, social media could have been used more effectively. In my interview with other tracks about their hazardous weather policies, I learned that social media is an important channel for tracks to get messages out to fans. There were many tweets from myself, Scott, and from others about the approaching weather well in advance, several of which tagged the track, but the track's official Twitter account was silent until this tweet. ​Sending out one tweet an hour after the threat first become imminent is not enough. Vickie told me that she used Twitter frequently at Sebring to get weather information, and she found it very helpful to know where the rain was located. There wasn't much effort from Sebring Raceway to keep fans informed and help direct fans to safety. There aren't many places at Sebring to find shelter, but at a minimum, they could have retweeted me: 

By Doug Schneider

Here's what the radar is showing across Florida and the Gulf of Mexico this morning (Sebring is near the red dot): 

There's not much activity near Sebring as of 8 am, but you can see a large area of showers with some thunderstorms that is moving toward the east-southeast. These showers are expected to arrive in the Sebring area this afternoon, roughly between 1 pm and 3 pm. This image of model-simulated radar shows what the radar might look like around 3 pm:

Don't take that image too literally as it is a model simulation and subject to errors, but this does give a rough idea of the timing of showers and thunderstorms in the area. Other models support this timing, so I have the highest rain chances today around 2 pm. 

The Storm Prediction Center has Sebring in a marginal risk area for severe thunderstorms. Don't get too excited or nervous about that. A marginal risk is very low, but it is non-zero. There may be some gusty winds with the storms, perhaps 30-40 mph. Rain could be briefly heavy too. Total rainfall amounts today are expected to be between a quarter and a half inch, although if a heavier storm moves right over the track, amounts could be higher. 

Once this complex of storms moves through, the chances of rain will be decreasing. There could still be a shower into the overnight hours, but the coverage of showers around the area should be less than in the afternoon. 

You can watch the radar by clicking on our live radar feed at the top of the page. I'll be updating conditions from my Twitter account - @Race4caster. 

By Doug Schneider

It's going to be another warm and muggy day at Sebring today for the CTSC race and WeatherTech Championship qualifying. Much like the past few days, highs will reach into the upper 80s, and with dewpoint temperatures around 60, it will feel rather uncomfortable. Unless you're from Florida and you are used to that sort of humidity level. 

There is a small chance of some showers around the area this evening. The qualifying session ends at 5 pm, so I don't think any on track activity will be affected if there is an isolated shower. 

Saturday continues to have a good chance of showers and thunderstorms, and the timing of the best rain chances is coming into better focus. While there is a chance of showers any time of the day, it appears that the best rain chances are in the late afternoon and evening, during the second half of the race. This should make for an interesting finish. 

Here's the latest NWS forecast of rainfall amounts:

Sebring (near the yellow dot) could see around a half inch of rain from Saturday morning through Saturday night. Some of this may come after the end of the race, so I think the amounts during the race will be between 0.25" and 0.5". There are still some model disagreements about how much rain will fall, but there is better model agreement on the afternoon/evening timing for the bulk of the rain. 

By Doug Schneider

Today will begin with some fog and low clouds at Sebring, but they should clear out by around 10 am, leaving mostly sunny skies through the rest of the day. Much like the past few days, highs will reach into the upper 80s. 

The chances of rain on Friday are looking a little lower now. There is still a slight chance of some afternoon showers and thunderstorms developing, but I think the coverage of any showers will be isolated. Most likely, Friday will stay dry. 

Saturday still has a good chance of showers and thunderstorms, but the situation does not look quite as wet as it did a few days ago. This does not look like a 2015 Petit Le Mans, which had a tropical cyclone interacting with a frontal boundary to produce an extended period of heavy rain at Road Atlanta. While I do think that rain is likely at some point during the race, mainly Saturday afternoon and evening, I don't think it will be a prolonged heavy rainfall that will cause significant delays in the race. I'm holding the chance of rain at 60% at this point because there is still a model (NAM) that shows no rain at all on Saturday. It is an outlier, but I am hesitant to raise the rain chances when there is still disagreement in the models.

Here's the forecast rainfall from the NWS for Saturday (Sebring is near the yellow dot):

The dark blue is between 0.5 and 0.75 inches. Honestly, from what I've seen in the models this morning, I think that is on the high side. Most of the models are below this amount. That might be a maximum amount that is possible. A more likely amount in my opinion is between 0.25 and 0.5 inches.

​I'll have another forecast update tomorrow morning, and hopefully the rain amounts and timing will be coming into better focus.

By Doug Schneider

Latest forecast graphic: