SSB of late (my theory on what's wrong)

[DeanDavis]

As the kiteboarders with big kites know it has been pretty thin pickins for the last month or so down at UL. Our last attempt on Thursday was just barely a rideable session. I needed my 20m kite and my biggest board to keep up. If you weren't ready to go big you were sitting on the beach. It was also unusually varied for a SSB session. We would ride 10 minutes fully powered then 30 minutes of “just barely” then 10 minutes of “I hope I can just keep the kite in the air”.

As we packed up with the sun already set I started to feel a SE breeze and then I figured I knew what had happened. Spanish Fork Canyon was pushing against our coveted wind. As I drove home that push became very apparent and at the mouth of the canyon it was probably blowing 35 mph.

Normally the canyon doesn’t push until we get out of the water (i.e. about an hour after the sun goes down) but the monsoon pattern makes it a bit different. My theory on this is that normally SF canyon blows (drainage flow at night) because the high elevations cool rapidly when the sun sets and the cool (dense air) drains down the canyon (just like a river of air). Normally during the day things are more equal and we don’t see the same flow. But the monsoon (this is my theory part) is like a big swamp cooler when it rains on the Wasatch Plateau making the high elevation cool like at night so we get the flow that we normally only see at night. Part of this theory comes from watching the local scene where dark thunder clouds to the SE don’t necessarily mean it will be windy, only sometimes which I am thinking is the difference between it raining or not (which I can’t tell from my vantage point at the mouth of the canyon). It’s kind of like that flash flood thing where dark clouds over you or upstream don’t necessarily mean flash flood or sunshine over you doesn’t mean no flash flood. It all just depends on whether it is raining upstream (which you may not be able to see).

To give you an idea of what our north is fighting against the average wind speed for the mouth of the canyon has been 8.8m/s (19.7 mph) for the last three weeks (a wet dream for wind energy, our cost of energy competes head to head with the big boys (coal) with that much wind resource). That number includes times when the wind isn’t blowing. If I remove the light breezes (i.e. what is the average wind speed when the wind is blowing) we see an average of 10.8 m/s (24.2 mph). We can also look at it this way, the wind has been above 6 m/s (13.4 mph) 70% of the time over the last three weeks. In a nutshell Spanish Fork Canyon has been a very windy place. Doesn’t anyone have a rich uncle that wants to buy the gravel pit at the mouth of the canyon and fill it up for us deprived windriders?

I don’t know if anyone tried yesterday (the 12th) but I think the canyon won the battle again. I saw that PVU was trying to push NNW (four readings at 8 and one reading at 13) but then the canyon pushed harder and PVU goes SSE at 7:15.

So that begs the question, is the SE rideable. I have ridden it only a few times. It needs a pretty good push (crankin’ out of the canyon, like 35+mph) but that is not unusual during the monsoon. Probably the thing I like the least is that it is just about perfectly offshore at SSB. Utah lake is a big lake when you start thinking about drifting into the middle with your kite tip folded over. It is also not nearly as clean as the north. It is more like Rush in the afternoon.

The predictors are all good (including Craig) for some fun tonight but my internet searching will not only be watching Bluffdale and PVU but also the radar over the Wasatch Plateau.

[Craig Goudie]

Hi Dean,

I'm a proponent of good localized data, and I love it when I see this kind
of analysis, because I'm not down there much and not familiar with
how the canyon drainage might effect SSB. From a more global standpoint
it should blow down there this evening, so, if you go, please post
and let us all know what happened. We can all use the data point.
And now that you have a theory, we can monitor and make more informed
decisions.

More pseudometerologists, more data, better forecasting, that rocks!

Good luck,

-Craig

The predictors are all good (including Craig) for some fun tonight but my internet searching will not only be watching Bluffdale and PVU but also the radar over the Wasatch Plateau.

[Marty Lowe]

I called Dean around 3:30
asked him how the sky looked in S.F. canyon
He said "pretty clear, and no canyon wind"
Vern and I left and had 16.5m to 19m wind till dark.

If Dean is willing, I'd like to see him do an afternoon update
on the days ULSSB is "on the radar"

Not much beach, rigging on driftwood, and carp
the road down to the water is narrow and overgrown.

-Marty

[whit]

Dean, Marty,

Great kiting with you at SSB this evening. Sounds like Dean's theory worked out well. Afternoon updates on the opposing canyon winds would be awesome. Is there a site on the Mesonet that shows the SF canyon area?

Lots of fun on 16 to 25 meter kites. That beach is a lot smaller than I can remember it. Does anyone know the lake level? They must monitor that someplace.

Keep riding

Whitney