Article by: Davis Straub
Strong winds, cooler moist air over a hot desert,
large high pressure to the east which creates winds in a consistent direction
for a distance long enough to set sailplane records, mechanical lift from
gradually rising terrain to the north with a southerly wind, streeting at 9 AM
with cu's forming before sun rise, early starts for long days, strong lift
during the middle hours over the hill country, consistent very good conditions
day after day when the normal weather pattern sets up.
Gary Osoba has been studying the weather patterns over southern Texas for a
number of years. He has found that the Bermuda high sets up in the Gulf of
Mexico and stays there for a couple of months. When it's sitting to the south of
the southern tip of Texas, the winds on its west side are from the south
straight up the state of Texas. The high is so big, that the circular flowing
winds are essentially going in one direction, north, for the length of a hang
glider flight (under 500 miles).
These winds circulating around the high are bringing in cooler moister air from
the Gulf and pushing it over the hot dry Texas alluvial plane north of the Rio
Grande. This cooler air, a few thousand feet thick, is cooler than the desert
even at night. Even as the desert radiates its heat back into the clear sky, it
is often still hotter than the cool air coming up from the Gulf. Sometimes, in
the early morning, clouds will form at 1,000' completely covering the area
around Zapata. They will break up around 9 AM, forming streets of cumulus
clouds. Streets formed by the winds.
The winds can be strong, 20 mph on the ground and 30 to 40 mph up high. These
winds are fed by the strong high pressure over the Gulf. To set world records,
you need strong winds to go along with the moderate to strong lift. The winds
provide the push, as well as the cool air, which provides the initial lapse
To be able to stay up in the early morning relatively weak lift, before the
desert floor is heated up by the sun, you need cu's to see the lift, and
streeting to see the lift lines. You need streeting to follow the general
direction of your flight so that you can get a fair distance even when the lift
After the first inversion is broken (when the desert floor has heated up the air
below it), and the first lower cu's disappear, you need the second set of cu's
to form, and to be set up in streets by the winds. You've got be able to get
high enough in the first cu's to be able to stay off the deck while the lift
goes from everywhere and weak, to sparse and moderate.
Around noon the cloud base will rise from 2 to 3,000' to 5,000'. The lift will
increase in strength and lift sources will be more widely scattered. With
streeting you will be able to get under the streets and concentrate on distance
and not worry so much about height.
Article by: Davis Straub
at: one of the ozreport.com newsletters Summer
Where else would we go?
That's what Gary Osoba answered when I was lamenting about the two hurricanes,
one tropical storm and the front that came through Texas this year during our
two week only WRE. He couldn't think of another spot on earth with a weather
feature big enough to allow him to fly the Alisport Silent 2 over 801 miles in a
As I write these words, I think about all I have written and done to try to
illustrate the magic that you can find in June and July (August, too) in south
Texas, for those ever so few of you who really want and are ready to go for the
Ultra Marathon of cross country hang gliding. Does it make an impression at all?
Does anyone outside a very small set of folks get it? Well, maybe they just
Oh, so you think that there really is a better place on earth for the Ultra
Marathon? Some place here where you regularly fly? Really? Just how many world
records have been set at your favorite spot?
Have I said before (more than a dozen times) that it's the wind? The wind makes
all the difference, especially in my morale and attitude. When I'm flying over
the ground at 60 mph when gliding, when I can easily get to clouds that are so
far away, when I see that I can make it easily to the next available landing
area, when there are so few at first, I just want to continue to ride the wind.
And what about that early morning launch, the one that provokes so much anxiety
before launch, then becomes a game of staying up in anything while drifting over
the lands behind locked gates. But there's the ten mile glide above the clouds
and already you are almost at the first public road as you finally get low
enough to come in under a solid cu. There's the fact that you can launch before
9 AM at all. There's the tow to the east that makes it easy to get around the
airspace 40 miles away, an hour later. There's the fact that as the morning
progresses (even in the first hour) the cloud base rises and the thermals gain
strength. Where else?
What about that early morning wide spread lift? What about a day full of light
sink when you are not in lift? What about being able to stay up over the most
shaded ground? Where else?
Then there is the ride up the highway as the cloud base rises and the clouds
begin to street up. There are even cu's underneath cirrus. Every one of these
cu's is producing. The land is rising up slowly and the cloud base rises as the
morning progresses and if you are very good and started early you can have 100
miles by noon. Where else?
The country side opens up and the anxiety related to making sure you've got a
good landing area within glide is relaxed, as you find yourself 170 miles out,
and getting into the hot rocks of the hill country where the land rises up
abruptly as does the cloud base. You can follow up a valley that cuts through
the hill country and provides plenty of safe landing areas. Where else?
The wind has been blowing and it has been blowing straight for hundreds of miles
and now it is going to keep blowing straight to the north for many more hundreds
of miles as you get up on the Edwards plateau and the cloud base rises to 6,000'
AGL to 9,000' AGL. On many days the streets are lined up and you just stay in
the streets. Where else?
In this farm and ranch country you have plenty of roads and it's easy to land
anywhere as the sun goes down between 9 and 9:30 (10 to 12 hours after you
started). You've got an extra half hour if you've brought your strobe light. Be
sure to stay out of the minimal airspace at Lubbock. Where else?
So, just where else on earth do all these things come together?
Two years (2000 and 2001) of stellar conditions, where 200 miles was a failed
flight, one that you cut short so that you can get back and try again on the
next day. The next year, the nine year drought ends, and we get two good days
and four world records. In 2003, a hurricane and no good days. In 2004, it's
still wet, and we get a good week with wet ground conditions and two world
In 2005, as above. Three world records before the second hurricane. One 200+ and
one 365 mile flight on the last good day. Three good days (none as good as the
first two years).
Have I made my case? You be the judge.
Okay, how about way northern Australia (Hughenden, Queensland, Australia) in
April? Does the wind blow out of the east at 15 to 20 knots every day? And will
that make up the limited day length in the autumn? Look it up on Google Earth.
Follow the road west.