Hey all! Wish I was there this year with ya but couldn't sign up due to financial issues. Anyway, as I have done before, here's my latest weather discussion and forecast:
First the big issue you should be aware of is that it will be VERY HUMID during the race. There are showers/thunderstorms forecast there in the overnight hours, but they will herald the arrival of this very warm and humid air. Dewpoints will be in the low 70s during the race and this is like Florida in the summer. Relative humidity will range from 90% at race start to 65% at 2PM. Those numbers are pretty high if it's not raining. So although we've had warm to hot weather here, we haven't had this type of humidity. Two things to be aware of:
1. Even with the breeze that will pick up, you'll likely be dripping on the run
(and probably the bike too!
). The humidity will affect your ability to cool down. So, hydration and electrolyte replacement will be critical. I would prepare to take more than you did during training as we just haven't had this type of humidity.
2. It will seem hotter than it is. While temperatures during the early afternoon will only be mid 80s, Heat Indexes will be in the 90s. It doesn't look like full sun for the run like in 08 but it will still seem hot.
The good points to the forecast is that there will be a breeze at least attempting to cool you down during the run and skies aren’t looking like full sun. Still, prepare for the humid conditions during the race and adjust your race strategy as needed.
So by the numbers:
Temp: start 75, 11 AM 82 Heat Index 87, 2 PM 86 Heat Index 93
Dewpoint – 72 to 73 the entire race!
Relative humidity: start 87%, 11 AM 74%, 2 PM 65%
(those are high numbers for it not to be raining!
)
Winds: light at the start up to 5 mph WNW, becoming NW 5-10mph during the rest of the race
(possible headwinds for return on the bike
)
Water temp – the weather station near the bridge in Cambridge is reading 77 degrees
Chance of rain – 32% at race start but dropping to 20% as the race goes on. This means the majority of the rain is now forecasted to fall overnight tonight, with possible lingering showers near race time. So for the rest of the race, perhaps an isolated shower forming, especially during the early afternoon.
I might send out another update if anything really changes.
Good luck, folks!