Yesterday I had the extraordinary luck to witness a very serious micro burst while sailing  on Carter Lake.

The race was delayed for lack of wind and when we started I was cursing myself for not putting up lighter sails.  At the start we had maybe 3 mph which built to maybe 8 when we rounded the first mark.  Heading back to toward the starting line the wind continued to increase slowly and a medium sized 15mph gust came through.  This was  followed by some twitchy shifts that caused me to fall off the wind in order to keep the sails pressurized.
The micro burst touched down about 1000 yards ahead and turned the already dark water black. I could see  a tremendous amount of Virga that seemed suspended 500 to 700 ft ahead creating almost an hourglass shape of darkness.  It really helped to watch this from the water, it sharpened the edges so that it was possible to visualize what the air was doing.   I suspect that people on the West .... North .... East.... shores all felt the gust coming coming from the center of the lake.
We had maybe 30 seconds and when it hit I was surprised by the strength of the burst.  It seemed like 40 mph, and... it might have been stronger..  I spilled the main and ran a beam reach with the heavy Genoa pulling like a Clydesdale. Eventually I had both sales spilling wind and rode through the weather at close to hull speed.  The worst of it lasted maybe 2 minutes but if you ask anybody who was on a boat they will tell you is seemed much longer.
I know the puppy did.

I can remember few weather events that became so violent so quickly.  The dust devil in Reo Puerco two years ago and a once or twice on Dillon.  Even Chatfield had a few slam bamm microbursts.  I particularly remember one storm that couldnt't be called a micro burst it hit very quickly but also had sustained winds and rain with gusts above 50 mph.  It was one of those times that the waves and spume reminded me of blue water.




Yesterday was unique in that we lost one boat and turtled another.  All of the "casualties" were experienced and capable sailors that just found themselves in the wrong place at the worst time.    I think the boats north of us were closer to the center and more likely to be subject to dramatic wind shifts.  Just the kind of thing that turns the high side into a very low side in less than a heartbeat.   We saw more than one hull laying on its side and everybody was scrambling to maintain control.   

Paradiso isn't a particularly heavy boat but it better able to stay on her feet than a Santana or J boat in a surprise blow.    We tacked once between the first gust and the micro burst and during the worst of it,  Dawn and I were forward in the cockpit with me on the helm and her manning the Genoa and clutching the puppy.  He had been tethered to the lifeline but still in danger of being thrown overboard.  

If you know or have hear John McGinley ... He is one of the best meteorologists around.  Here was what he wrote up for Carter Lake Sailing Club

Yikes...quite a microburst at the lake today. The atmosphere was
primed for these things with high based thunderstorms, dry conditions
below the storm, and warm temperatures at the surface. The tip off was
lots of virga in the sky; that is, precipitation falling out of the
cloud but evaporating before it reaches the ground. The attendant cold
pool hits the ground at high speed creating 50-60mph winds. We were at
the Rockies game and witnessed a similar microburst with at least
60mph winds blowing hats off fans, moving dust and trash, and moving
the roller for the field tarp (a very heavy item). The size of this
disturbance couldn't have been more than 500-1000 ft across, very
small, and I would guess it lasted 2 minutes. Other damaging bursts
happened around the I25 corridor including Greeley. Quite impossible
to predict exactly where and when, so one can only scan the skies for
virga or precipitation streamers, and prepare to respond rapidly to
hazardous conditions. So much of this is being in the wrong place at
the wrong time. Best of luck Duane, in recovering Streaker. I am so
glad that no one was injured and all other boats are floating again.
John