Spring Break at Ed Levin

Safety and Fly related incidents and accidents
Karl_A
Posts: 770
Joined: Sat Jul 19, 2008 6:00 am

Spring Break at Ed Levin

Postby Karl_A » Sun Mar 14, 2010 11:27 pm

While the combination of North or East wind aloft and inversion below is usually benign, the combination of North or East aloft and good lapse rate below can make for changeable and treacherous winds on the lower hills (150, 300, 600) and LZ. This is because with an inversion the air aloft is warmer and doesn't tend to mix with the colder lower air. It just blows over the top of the mountain and leaves the lower hills and LZ alone. If there is no inversion and especially a good lapse rate, the wind aloft will tend to mix down into the LZ making those changeable and treacherous winds.

Today (Sunday 3/14) was just such a case, and at one point had a nice breeze straight up the 600 launch while the 300 launch was blowing hard down. Yow!

So: North or East wind aloft, good lapse rate, Beware!

Karl_A
Posts: 770
Joined: Sat Jul 19, 2008 6:00 am

Re: Spring Break at Ed Levin

Postby Karl_A » Sat Mar 27, 2010 9:07 am

Like today, Saturday 3/27.

WOR soaring forecaster has the -3 level about 2700 msl, Ed Levin windtalker says 13-21 NNE 17, NNE 19, NNE 18,NNE 18 at 9:04 am.

Karl_A
Posts: 770
Joined: Sat Jul 19, 2008 6:00 am

Re: Spring Break at Ed Levin

Postby Karl_A » Sat Apr 03, 2010 1:17 pm

This is the time of year when normally benign and boring Ed Levin can generate its share of excitement, when nice soarable conditions get stronger and Stronger and STRONGER, as it might tomorrow Sunday 4/4 according to the NWS:

THE COLD FRONT APPEARS TO BE QUITE STRONG FOR THIS TIME OF YEAR AND MODELS DEPICT AN ABRUPT WIND CHANGE LATE SUNDAY AFTERNOON. FOR NOW WILL CRANK UP THE WIND GUSTS IN THE GRIDS TO AROUND 40 KTS FOR THE COAST AND HILLS

40 knots is 46 mph so if you find yourself pointing closer to into the wind than along the ridge it might be a good time to think of heading out toward the LZ. This one is not predicted to turn SE which can be a problem for anyone caught north of the tower launch if it picks up and turns SE, finding big headwind and no lift and maybe even sink on the way to the LZ.

The Ed Levin tabular forecast

http://forecast.weather.gov/MapClick.ph ... pe=digital says

8 am S at 9 chance of rain
11 am S at 15 gusting to 23 rain likely
2 pm S at 20 gusting to 30 rain likely
5 pm S at 18 gusting to 28 rain definite

Karl_A
Posts: 770
Joined: Sat Jul 19, 2008 6:00 am

Re: Spring Break at Ed Levin

Postby Karl_A » Mon Apr 12, 2010 12:06 pm

Ed Levin LZ Evil Twin

The last post was about what can happen aloft when Ed Levin gets soarable, this one is about what can happen in the LZ.

Northwest and strong - This is like the usual afternoon Ed Levin LZ only more so, more wind and turbulence. Maybe it went north and everyone got flushed so keep an eye out for traffic. Fly your usual approach only more so - more airspeed, more control and if your toes are in the weeds and your ground speed gets much below running speed, go easy on the flare and if you're yanking on the control bar to keep the glider pointed into the wind and can't get it balanced, don't flare, run it on and call it good.

South and strong - This seems to be the most variable condition, with the wind in the LZ switching from SE to SW. I have even seen light N when the wind aloft was S at 20. Watch the wind sock as you are coming down to see what it's doing. If you're landing because you're cold and tired, don't wear yourself out diving through lift. Find some sink, even if you have to fly upwind of the LZ, and turn in it. Relax, be patient, watch the wind sock and traffic. If it's SE, the lowest trees and terrain are behind the 40 foot hill so the best place to land is down wind of the 40, upwind of the 3 oak trees, not too close to the 40. If it's S or SW, the H3 spot or uphill toward the wind sock is good. Don't get downwind of the trees, either the eucalyptus trees by the parking lot or the 3 oak trees on the other side of the road because there be rotor. The area around the 300 and 600 can be very buoyant so if you don't like what the wind sock is doing you can delay your landing until it looks better then dive in and land before it gets weird again. The general principle is 'Don't land in an LZ you can climb away from.'

Airspeed is your friend and once you are turning final and committed, forget thinking and fly that glider!


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