Amazing Wind Shear Today

On Sat, 29 Nov 2003 21:13:15 -0800 "BTIZ" wrote:

the wind that produces "lennies" has gone laminar.. it's a smooth flow well
above the ridge tops.. the turbulent air is down low.. normally on the
downwind side.. the rotor.. the "wave" that forms above is smooth.. sine
wave type.. and the upward part of the sine wave is where the lift is.. our
in front of the lennie..


Ok, well it sure sounds fun. If you had a motorglider you could have played
in them I suppose? A ride in a glider is what got me interested in flying.
Going to have to get my glider rating one of these day.



The ones we were watching today were about 25nm away.. normally we can tow
over to the lower part of the Spring Mountain Range, and get into lower
ridge lift and work up into the lenticular flow on the upper peak.... but
the winds that were hitting the upper (northern) end of the ridge did not
come far enough south.


Gliding sounds like a whole new interesting set of challenges.


R. Hubbell



BT

"R. Hubbell" wrote in message
news:Badyb.12188$ZE1.9049@fed1read04...
On Sat, 29 Nov 2003 18:57:49 -0800
"BTIZ" wrote:

the wind had gone "laminar" and you live in the flat lands..

we had light and variable all day on the ground.. winds at 6000ft (first
altitude forecast) was 200/6 at 9000 they were 250/25 and stayed that
way
all the way to FL300, there were wonder "stacked lennies" on local Mt
Charleston all day long.. (Mt Charleston tops out above 10K

not much lift in the local area.. some very weak thermals down low.. not
really workable.. the lennies were to far away to be towed to.. and the
local 8000ft ridge was not producing ridge lift..


Why would you want a tow to where lenticulars clouds have formed? I
thought
lenticulars are a sign of laminar flow, not turbulent flow. Or are the
lenticulars just the sign post to tell you that there is lots of wind and
there should be some lift near where there are lenticular clouds?

We get lenticulars here all the time, sometimes they march right out to
the Channel Islands. It's a fabulous sight to see. Although it'll
mean a bumpy ride for sure.


R. Hubbell


BT

"Jay Honeck" wrote in message
news:Njcyb.362928$Fm2.362681@attbi_s04...
We flew to Rantoul, IL today -- home of the Chanute Air Museum, on the
site
of the former Chanute Air Force Base. The wind was predicted to be
howling -- winds aloft were calling for 54 knots at 6000 feet! -- but
the
sun was shining, and we were enjoying our first Saturday off since
last
Oshkosh. So off to Rantoul we went.

Our local AWOS was calling the wind 180 at 13, gusts to 21 -- strong,
but
right down one of our three runways. Takeoff was a non-event, and the
cool
temperatures meant we were soon climbing out at 1200+ fpm, even with
84
gallons and four aboard.

As we passed through 500 feet AGL, we experienced some moderate
turbulence,
followed by some really "hinky" air -- you know, the kind that lifts
first
one wing sharply, then the other? It's an almost uncontrolled
feeling,
where you really just kind of keep things pointed in the right
direction
as
you climb through it.

Then, the most amazing thing happened. Our ground speed, which had
been
an
anemic 90 knots or so climbing out in a shallow "cruise climb",
suddenly
accelerated sharply. Within seconds, we were doing 130 knots climbing
on
the SAME HEADING that had given us a headwind just moments earlier!

Interestingly, the air instantly became silky-smooth, with hand's off
flight
producing an absolutely rock-solid heading. As we leveled off at
5500
feet, our ground speed rapidly climbed through 170 knots, meaning that
we
had a solid 30 knot tailwind, heading South. As we passed Muscatine,
the
smoke from the power plant clearly showed a wind out of the South, yet
at
5500 feet we were riding a strong tailwind from the North.

On the way home, Mary stayed down below 3000 feet, where the headwind
(it
was no longer out of the South down low, dang it) was considerably
less.
We
still dragged home at 117 knots, meaning we were bucking a 25 knot
headwind.
The one time ATC asked us to climb to 3500 for radar coverage, we
instantly
lost 25 knots in ground speed!

Again, the air was smooth as glass, however. It's hard to envision an
air
flow that could cause such severe wind shear, yet not also cause
moderate
to
severe turbulence.

Never seen anything quite like it.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Did you go in the museum and sit inside the B-52 cockpit? Biggest rudder
pedals and trim wheel I've ever seen.

"Jay Honeck" wrote in message
news:Njcyb.362928$Fm2.362681@attbi_s04...
We flew to Rantoul, IL today -- home of the Chanute Air Museum, on the
site
of the former Chanute Air Force Base. The wind was predicted to be
howling -- winds aloft were calling for 54 knots at 6000 feet! -- but the
sun was shining, and we were enjoying our first Saturday off since last
Oshkosh. So off to Rantoul we went.

Our local AWOS was calling the wind 180 at 13, gusts to 21 -- strong, but
right down one of our three runways. Takeoff was a non-event, and the
cool
temperatures meant we were soon climbing out at 1200+ fpm, even with 84
gallons and four aboard.

As we passed through 500 feet AGL, we experienced some moderate
turbulence,
followed by some really "hinky" air -- you know, the kind that lifts first
one wing sharply, then the other? It's an almost uncontrolled feeling,
where you really just kind of keep things pointed in the right direction
as
you climb through it.

Then, the most amazing thing happened. Our ground speed, which had been
an
anemic 90 knots or so climbing out in a shallow "cruise climb", suddenly
accelerated sharply. Within seconds, we were doing 130 knots climbing on
the SAME HEADING that had given us a headwind just moments earlier!

Interestingly, the air instantly became silky-smooth, with hand's off
flight
producing an absolutely rock-solid heading. As we leveled off at 5500
feet, our ground speed rapidly climbed through 170 knots, meaning that we
had a solid 30 knot tailwind, heading South. As we passed Muscatine, the
smoke from the power plant clearly showed a wind out of the South, yet at
5500 feet we were riding a strong tailwind from the North.

On the way home, Mary stayed down below 3000 feet, where the headwind (it
was no longer out of the South down low, dang it) was considerably less.
We
still dragged home at 117 knots, meaning we were bucking a 25 knot
headwind.
The one time ATC asked us to climb to 3500 for radar coverage, we
instantly
lost 25 knots in ground speed!

Again, the air was smooth as glass, however. It's hard to envision an air
flow that could cause such severe wind shear, yet not also cause moderate
to
severe turbulence.

Never seen anything quite like it.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Peter Duniho wrote:
*"R. Hubbell" wrote in message
news:Badyb.12188$ZE1.9049@fed1read04...
Why would you want a tow to where lenticulars clouds have formed?

Two words: mountain wave. *


Formation of the mountain waves relies on several conditions. The
atmosphere is usually stable and an inversion may exist. The wind needs
to be blowing almost constantly within 30 degrees of perpendicular to
the barrier at a minimum speed of about 20 to 25 knots at the
ridgeline. Wind speed needs to also increase uniformly with height and
remain in the same direction. Wave crests can be upwind or downwind
from the range and their amplitude seems to vary with the vertical
stability of the flow. The crests of the waves may, (depending on the
air having sufficient moisture content), be identified by the formation
of lenticular clouds. Mountain waves can even extend into the
stratosphere and become more pronounced as height increases. I remember
reading somewhere of U2 pilots reportedly experiencing mountain waves
at 60,000 feet!!. In Australia, mountain waves are commonly experienced
over and to the lee of mountain ranges in the southeast of the
continent. They also often appear in the strong westerly wind flows our
east coast experiences in late winter and early spring. We definately
had some this year in mid-August for periods of up to 3 &4 5 days at a
time!
MQD_117.3


--
mqd_117.3
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

Did you go in the museum and sit inside the B-52 cockpit? Biggest rudder
pedals and trim wheel I've ever seen.

Yep! The kids and I thought that was the best part of the museum!

Best of all, because it's not a real busy place, the four of us actually
spent more than 20 minutes sitting in the "cockpit" (really the forward
fuselage, with ECM stations and everything) playing "SAC commander".

Very cool.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

I was driving over the mountain here in Wales one night during
rather high winds...I couldn't get my Ford Fiesta (still air top speed
90mph) to go over 40mph. I didn't try turning round and going the
other way! :-)

Paul

"Nathan Young" wrote in message
om...
Ken Reed wrote in message
...
I saw a low of a 27 kt
ground speed in my Mooney !

Ouch! That's brutal! Nothing worse than flying and watching the
semis pass you on the interstate below.

Paul Sengupta wrote:

The damnedest thing I've seen in that respect was from standing on
the ground. I saw two layers of cloud fairly shifting over the ground
but the thing was they were moving in different directions, at right
angles to each other.

I came out of Raleigh, NC once, headed for New Jersey. Because of an overcast,
I had to stay down around 2000' for the first 100 miles, but then was able to
go to 9500'. I had about a 10 knot headwind down low and about a 40 knot tail
wind up high. I never did get used to it - I would look for my next visual
waypoint on the ground, and it would already be behind me!

George Patterson
Some people think they hear a call to the priesthood when what they really
hear is a tiny voice whispering "It's indoor work with no heavy lifting".