A few comments. We asked our wind expert - John Kellogg (JK) - to comment on the weather. Yesterday morning, when the wind forecast was for a SSW of 7-8 mph, we asked JK how that would impact the race.
The course runs mainly West to East but it does go slightly from the south to the North as shown here:
Here is what JK wrote:
The forecast has changed since he wrote that. It's expected to be more of a southerly wind. Last night, it was supposed to be out of the South but now still says SSW and then S.
There should be a tailwind component of 4-6 mph for the race, which in theory would make the times about 55 to 85 seconds faster than they would be if there was no wind.
A little bit about wind readings: Unless a weather report specifically indicates the readings are those at ground level, wind speeds can be assumed to be taken 10 meters above ground in open areas (e.g., airports), and the wind speed that runners experience at chest/head level usually ranges from 40% to 80% of the reported speed, depending on surrounding objects (open areas vs. buildings, trees, etc.) and elevation (low sections of road vs. hilltops or overpasses). That's why you'll often see wind gauge readings of 4 mps (about 9 mph) at track meets when current weather reports show a 20 mph wind and it sure feels like it's a lot stronger than you'd expect 9 mph to feel. The wind gauge is actually closer to the ground than the heads and chests of the athletes, so runners are typically experiencing abut 12 mph of wind on a 20 mph wind day (unless the race is in an extremely flat, wide-open area like a prairie or a coastline, in which case the chest-level wind speed could be up to 80% of the reported speed).
But for practical purposes, we can usually just use the reported wind speed to make time comparisons against calm conditions. Those comparisons can never be perfect because of the quirky nature of wind and the effects of terrain and surrounding objects. The real world isn't a wind tunnel, so take any prediction about the time benefit of a tailwind as a ballpark estimate.
If it was straight out of the South, JK said on the phone it would probably help around 30 seconds versus there being now wind.
In summary, the conditions are there for a fast day if the runner's decide to run fast. Temps will be in the 50s and sunny. A little warmer than ideal but a perfect day all told when considering what the spectators want.
A few more intersting tidbits that I got from the press conference on Friday but haven't shared yet.
I talked to top Ethiopian men's entrants in defending champ Desisa as well as 2:05:27 man Regassa who trains with Desisa.
Both said they were in shape, but when I asked Regassa who was in better shape, he didn't hesitate at all. He pointed to Desisa. So the scuttlebutt is he's very much ready to defend.
I also talked to Kenya's Kimetto who indicated he was happy with his fitness as well.
In terms of getting seeing an American winner in Boston, here's one interesting scenario to consider down the road. Maybe the USA's best bet it to get a citizenship change.
I asked LetsRun.com visitor Worku Beyi - the husband and coach of Deba - the Ethiopian woman who lives in the bronx - if they might become US citizens since they live here.
He said, "Yes," and revealed he is actually getting his citizenship in October. I then asked if this meant Deba would run for the US in 2016. He thought she'd have to wait 5 years for citizenship (and said she was hoping to get a green card) but I told him I thought cirizenship could be expedited (wasn't it for Khanouchi).
As for Desisa, he was outfitted in some sweet red, whie and blue adidas gear. I told him that looked like an American outfit and he said he'd love to get an American passport.
Deba is obviously a real candidate. Desisa's mark seemed more like just a friendly statement.
In the press room, they hopefully will have a split update each and every mile - much more than what you can get via tracking. I'll try to update them as I get them (and am actually going to be sending them via text to a top coach who asked for my help. If that American wins with a late surge, of course, we will be taking credit for it).
I hope everyone enjoys the race - it should be awesome.
In case you aren't up to date.