By: Stephen McCoy
After a full day of racing, we’ll end Memorial Day weekend with a pair of GT and GTS SprintX races in the Pirelli World Challenge series. A low pressure system currently causing heavy rain to the upper Mid-Atlantic region will move eastward into the Atlantic Ocean overnight into Monday. As it moves off the east coast, winds in New England will shift to the northeast, bringing cooler air into the region. Wind from this direction will undercut the warm air in the region from Sunday, causing some low cloud cover and cooler temperatures in the low 50’s to start the day. With winds in the upper levels from the northwest and winds in the lower levels from the west, expect partly cloudy conditions mid-day into the afternoon. As the low pressure system continues to move further into the Atlantic, look for winds to change direction, coming from the south and southwest in the afternoon. With the winds being light, don’t expect them to help warm up the region too much, as the high temperature will be in the low 70’s.
By: Stephen McCoy
Nothing much to report for Saturday; should be a good day for racing with warm conditions to start the day and a high temperature in the low 80’s. As I’ve discussed before, expect some heavier cloud cover than Friday, especially into the afternoon.
A slight chance of rain is expected during Sunday night into the early morning on Monday. Other than some possible track drying before on-track activities, I don’t see any impact to the scheduled races for Monday. Expect some cooler temperatures for the morning with light winds from the northeast off the North Atlantic; surface winds will turn to the west and southwest after midday. Winds from the northwest in both the lower and upper levels of the atmosphere will clear conditions into the afternoon and evening. The low level winds will contribute to the cooler surface temperatures for the day.
By: Stephen McCoy
Not much has changed in the forecast for this weekend’s Pirelli World Challenge Grand Prix of Lime Rock. Winds in the upper levels of the atmosphere are expected to stay constant from the northwest, bringing dry air from Canada. At the lower levels, the general flow will be from the west and will be warmer than the surface in the early morning hours. This will set up a temperature inversion, and likely cause some low level clouds to persist. Once the surface temperature is warm enough to overcome the inversion, conditions will begin to clear. With westerly flow at both the surface and the upper levels, some windy conditions are likely with some stronger gusts.
The low pressure system mentioned in the previous discussion is expected to now move out into the Atlantic Ocean during the day on Friday. However, a second low pressure system is expected to move into the Midwest region on Saturday. A warm front is expected to extend eastward out of the system into New England. There is a slight chance of showers associated with this front, but should hold off until after track activities have ended.
For Monday, the current long-range models are in some disagreement for the likelihood of precipitation and the high temperature. The current runs of the GFS model indicate that for Monday, a moist atmosphere in the lower levels and cooler temperatures are likely to result in rain during the morning and early afternoon. However, the Euro model suggests warmer temperatures with little precipitation occurring at the end of the second GT SprintX race. Because of this disagreement, I’ve decided to indicate a slight chance for showers, though I don’t have very high confidence in the likelihood for precipitation. I’ll have a better understanding of what to expect for Monday in the next update.
By: Stephen McCoy
The Pirelli World Challenge series will be heading to New England for Memorial Day weekend for the Grand Prix of Lime Rock with racing on Friday, Saturday, and Monday. Conditions are looking nice for Friday and Saturday, but could get are a little more uncertain for Monday.
Starting with the upper atmospheric setup for Friday, the upper level jet stream is expected to set up over the Northeast US/Southeast Canada, bringing cool, dry air into the region. The low level jet stream will be bringing air into the region from the northwest as well in the morning hours before turning towards the west. The direction of the two jet streams in the morning will keep temperatures cool to start and will bring clear skies for most of the day. Little cloud cover, with the addition of westerly winds at the surface and lower levels, will allow for plenty of daytime heating and cause temperatures to reach into the low-to-mid 80’s. With both the surface and low level winds coming from the west, expect some breezy conditions with some gusts approaching 20mph.
A strong low pressure system over southeastern Canada is expected to track eastward Friday into Saturday. According to the latest runs of the GFS model, a cold front will set up north of New England and slowly move southward during the day on Saturday. With this setup, temperatures will likely remain warm overnight as winds will be from the south and southwest. Expect heavier cloud cover than Friday as moisture moves into the area in the lower levels of the atmosphere. A threat of rain is possible with the cold front; however frontal passage should occur after track activities have ended.
On Sunday, a high pressure system will develop over Canada before tracking southward over New England and into the Atlantic Ocean on Monday. Cool winds from the east off the Atlantic will keep temperatures cooler, with a low in the low-to-mid 50’s and a high around 70. Moisture off the Atlantic will likely result in some cloudy conditions for Monday.
By Doug Schneider
In my first forecast for PWC's Grand Prix of Virginia at VIR, I wasn't very confident in the timing of rain chances around Friday. Now, the models have come into much better agreement, and my confidence in this forecast is higher. The upshot of this forecast is that I expect the majority of on-track activity at VIR to stay dry, which is good news for those of us who will be at the track.
On Thursday, VIR will be between an exiting storm system that is delivering some rain to the area today, and another system that will be arriving Thursday night. All indications are that the test sessions on Thursday will be run in rain-free but mostly cloudy conditions.
A low pressure system will be tracking across the Tennessee Valley region through the day, then across the Carolinas Thursday night. This system could bring quite a bit of rain to VIR Thursday night, probably around a half inch but with the potential to produce up to one inch. There may also be some thunderstorms moving through overnight. The good news is that the models are in good agreement that this system will be exiting early Friday morning, and most of the practice sessions that day should not be impacted. I have a low chance of rain and a low impact mentioned on Friday mainly due to the possibility that some of the first practice sessions of the day could be delayed a bit, and the track will likely be wet to start the day. Through the rest of the day, I can't completely rule out an isolated shower in the afternoon, but any afternoon showers will be light and brief, with no lightning expected.
The rest of the weekend looks to be about as good as you could hope for this time of year in Virginia. Saturday will be partly cloudy with highs in the lower 70s. A cold front is expected to move across the area Saturday evening, but it will not have enough moisture with it to produce any rain. Behind the front on Sunday, a northwest wind will bring slightly cooler temperatures, with morning lows in the mid 40s and afternoon highs close to 70.
Doug Schneider, Scott Martin, and Stephen McCoy are race fans and meteorologists dedicated to providing accurate forecasts and timely weather updates at racing venues around the world. We forecast for IndyCar, Indy Lights, Pro Mazda, USF2000, IMSA, Pirelli World Challenge, World Endurance Championship, and Trans Am Series races, as well as major SCCA and NASA events.