Wednesday, May 17, 2017

Was Weather Behind the Record Times During the Windermere Crew Races?

On Saturday, May 6th both the men and women's crew broke long-term course records during the famed Windermere Cup races.  As noted by the Seattle Times:

The men’s winning time broke a 20-year-old course record set by Washington in the 1997 Cal dual regatta of 5:30.0. The women’s performance broke the 30-year-old record set by the Soviet Union national team in the 1987 Windermere Cup of 6:11.73.
Picture Courtesy of the University of Washington
What were the chances that both men's and women's teams would beat long-term records on the same day? Even the woman's coach Yasmin Farooq found it hard to understand.

Now I am the last one to detract from the stunning athleticism of the UW men and women's crew teams, some of whom I have had in my classes. They are fierce and disciplined athletes. But perhaps there was a meteorological/environmental factor that enhanced the times of both the Huskies and their competitors that day.

Let me explain.   

None of this was on my radar until I got a call  from someone from the Seattle police department (didn't note his name).  After assuring me that I wasn't in trouble, he told me that he was involved with the crew races and noted that the water seemed to be moving very fast (westward) during the competition in the Montlake cut (see map) ; he wondered whether that might have explained the records.  I mused that we have had a very wet spring and that there was a pulse of water moving into the rivers that weekend from melting mountain snow.  So maybe there was a connection.


The Windermere Cup Crew Races occur upstream of and in the Montlake Cut, a narrow passage between Lake Washington to the east and Lake Union to the west (red oval)

I told I knew who to call:  Larry Schick, lead meteorologist of the U.S. Army Corps of Engineers (USACE) in Seattle.  USACE runs the Hiram M. Chittenden Locks, which controls the water levels in Lake Union and Washington.  Larry was very helpful, and engaged the help of a hydrologist colleague, Adam Price.

The "plumbing"  of the region is relatively simple.  Most of the water that enters Lake Washington does so through the Cedar River (red oval below); that water then flows through the very narrow Montlake Cut (red oval above) into Lake Union and flows westward through the Locks before entering Puget Sound.  The outflow through the Locks and the inflow in the Cedar control the water levels in Lakes Union and Washington (there are minor rivers/streams flowing into the Lake as well).  Generally, the Corps keeps Lake Washington at around 20 feet during the winter and 22 feet in late spring.



This has been a exceptionally wet spring and thus the Army Corps has had to pass a lot of water through the Locks, resulting in strong westward flow in the Montlake cut (the race venue)

However,  the passage of a wet, warm front in early May upped the ante--it not only provided lots of rain, but also melted the bountiful snow in the Cascades.  As a result, the Cedar River surged, as shown by USGS Daily Discharge Data at Renton.  Blue is the actual this month and the orange triangles are normal,  The flow was WAY above normal on May 6th, reaching around 1800 cubic feet per second.  In fact, this was the greatest flow on record at that location on the that date.


According to USACE hydrologist, Adam Price, on race day the Lake Washington level was fairly stable and the Corps maintained an average release rate of 2800 cubic feet per second, enough to balance the Cedar and minor river inflows.  He told me that this was a very high outflow rate in May.   Using the 2800 cubic feet per second number and simple calculations, he determined the flow speed up the narrow Montlake Cut, finding unusually large outflow.  He did the same for normal May flow (850 cfs).   The result demonstrated that the boats were sped up considerably by the strong current, reducing their travel time by roughly 6 seconds.

So the wet spring and rapid warm up  resulted in increased flows that substantially reduced the travel time down the cut, and may have explained (at least partially), the records broken that day.

Interesting, the date of the previous Windermere Cup men's record (May 3, 1997) was also a period of unusually strong flow from the Cedar River into Lake Washington (see below).

The bottom line of all this is that it is possible that a wet spring and rapid snowmelt led to strong flow along the Windermere Cup race course that might have shortened the travel time appreciably.  

And it is only a rumor that the Husky Crew team has suggested that the US Army Corps of Engineers do a rapid release of water during the first Saturday of May 2018 😊


14 comments:

John said...

Fascinating.Just like how favorable tidal currents affect times in sailboat races on Puget Sound.

Dan said...

The cops have time to waste on fishing expeditions for performance-enhancing drugs, when victims of property crimes routinely have to clear out their whole day to make a police report?

Misplaced priorities.

John K. said...

John, it's not just races.. sailors who cruise anywhere in the region soon learn (sometimes the hard way) that you WILL plan your legs around the tidal currents. The currents are a close second only to the weather when it comes to safety and trip planning.

Soundman1402 said...

The Husky crew athletes still deserve kudos for their performance -- the heavier flow would have affected all teams equally, would it not? The Huskies still pulled off a win. Congrats to them!!

larchitech said...

I think it was climate change that caused the record breaking efforts. ;-P

John K. said...

Soundman - yes, they won the race against the other teams fair and square. That's not at issue. It's the time record that is questionable. If the water is moving, then the times should not be allowed for record purposes. It makes one wonder what else they cheat on..

jno62 said...

Good stuff, Cliff. Thanks!

JH said...

I race Grand Prix Hydroplanes. The Worlds Fastest Grandpa. Hold 3 APBA records, two of them straightaway records. The fastest one I set last summer is 170.680 mph (274.683 kph) When we do the runs we average a run in each direction and must be done within 15 minutes to negate wind and current flow. Jerry Hopp

Westside guy said...

Clearly there is something hydrologically significant about years ending in the number "7". :-D

Old Oar said...

Race times are always affected by wind and current. One can easily see the magnitude of that effect by observing a boat sitting still in the water, especially noticeable in a confined space like the Montlake Cut. A race typically lasts 6 minutes ... a shell sitting still in water that is moving will float some considerable distance in six minutes. It is easy to imagine an eight oared shell floating downstream 4 boatlengths (or more) in a six minute interval ... a fast eight would take 12 seconds to cover those 4 lengths.

An easy test to quantify the assistance factor would be to float boats in each racing lane for six minutes to see the effect of the current (and also the wind). This would give a reliable check on the validity of a course record. Such a test could also demonstrate whether there was an advantage (or disadvantage) to the various lane assignments. To make it more exciting for the fans, the starting line could be staggered, giving a head start to a boat that would be forced to row in dead water because of an unfortunate lane assignment.

A question comes to mind ... who determines which direction the boats will race?

The difference between rowing upstream or downstream in the above scenario would be 24 seconds. The very fast times of Opening Day were no doubt set by fast boats. But setting a course record with an assist from fast moving water is a curiosity that should be accompanied by an asterisk in the record book, especially since it seems arbitrary whether the race will be conducted east-to-west or the reverse.

John Marshall said...

Wait a minute... they race down-current and use the timed results to set a record? Even stranger that anyone in the PNW is surprised by this. Powered boats have to run reciprocal courses for speed measurements, but that doesn't work when you are dealing with muscles that tire.

Current is everything.

I remember a friend who sailed each year in the Swiftsure sailboat race on the Strait telling me that sometimes the best tool he has to increase his forward velocity to win a race is an anchor, especially around Race Rocks. Zero forward speed is FAR better than negative forward speed, which is easy to encounter when winds are light and currents are strong and against you.

JeffB said...

Like running records set at high altitude, these should definitely stand. If Mother Nature sets up some amazing conditions, then so be it. As long as all teams benefited equally, there's no reason to fault the UW for nature's helpful hand beyond their control or comprehension. Go Huskies!

John K. said...

JeffB - if the team set a time record due to factors other than their rowing skill, then the record is not legitimate. It's really simple.

Victoria Dale McKinnon said...

Ooh, well then let's built a venue in a temperature-controlled vacuum! That way, they won't be affected by atmospheric pressure, humidity, wind, rain, pollen, noise, trace amounts of carbon monoxide, or minute shrinkage or expansion of carbon fibers in the hull based on kelvin temps from above.
Based on your logic all records on the cut are void as are all Olympic, National, Regional and state records. Rowing is never in a vacuum.