It seems to me that they are leaving two days too soon (looking at
the winds forecast for Sunday and Monday):

Larry Bunner <<lbunner>> writes:

Five days of flying, 21 1/2 hours in the air four flights over 120
miles.

Haven't been able to make the big one due to not enough wind.

Launched at 9:45 today and was able to stay up even though I couldn't get very
high (2200'). This place has Zapata-like qualities for sure. The only difference
being that landing fields are plentiful too.

Flew for a long time below 3000' before it turned on. Then it got easy as the
lift became stronger (900 feet per minute) and the top of the lift increased
rapidly to almost 7000'.

Tomorrow, Saturday, is the last day and it looks like no wind again so 500km may
have to wait until next year.

I landed at the Castroville airport (west of San Antonio) just after 3:00 with
dust devils all around. It wasn't fun but I scraped in with no glider damage.