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#1
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Today, for the first time in weeks, dawned clear, cool, and calm. After a
VERY early spring (with temps in the 80s for over a week), we have experienced extremely high winds and record COLD temps. In fact, we broke the record here on both Sunday and Monday... (Take THAT all you "global warming" pessimists!) When we got to the hangar, the air was as still as death. The wind sock hung limp as a rag, and AWOS was reporting winds variable at nuthin'... Flight service mentioned nothing about turbulence (for a change) -- so we taxied out to Rwy 25 in anticipation of a smooth ride to Clinton, IA... Initially after departure all was smooth -- but by 1500 feet we were getting bounced pretty good. By 3000, we were inside a popcorn popper. Mary climbed to 7500 feet before we penetrated the haze layer, and popped out into the clear, smooth air on top. It was a VERY uncomfortable ride until then -- and, of course, she had to descend back down through it to land. On the return flight a couple of hours later, it was even worse. Now we had heating of the day, with the sun on the dark, freshly plowed fields -- and the ride was wild, indeed. However, again it was smoother down LOW -- which was bizarre -- than it was in the middle altitudes. I suppose after all the unsettled weather we've had the atmosphere is still stirred up -- but no one standing on the ground would EVER have guessed what was brewing and burbling just a few thousand feet overhead. By all appearances, it was the perfect day to fly -- yet it was the most uncomfortable flight we've had in a good long time. -- Jay Honeck Iowa City, IA Pathfinder N56993 www.AlexisParkInn.com "Your Aviation Destination" |
#2
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I've had this happen around Chicago, and conclude that in many cases
it's wind shear. Lake Michigan often establishes a mini-high over the lake, with wind flowing from the northeast over Chicago. The prevailing upper winds are some sort of westerly, and there's often a layer around 2500 ft where the 2 layers mix which can be surprisingly rough - smooth above, not too bad below. |
#3
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![]() Jay Honeck wrote: I suppose after all the unsettled weather we've had the atmosphere is still stirred up -- but no one standing on the ground would EVER have guessed what was brewing and burbling just a few thousand feet overhead. By all appearances, it was the perfect day to fly -- yet it was the most uncomfortable flight we've had in a good long time. A clearly defined haze layer can often signal the boundary between two airmasses. Turbulence is often (but not always) a possibility in this shear zone. Did you happen to check winds aloft and PIREPS? Usually, when it's dead calm on the ground and windy upstairs, you know you're going to be in for a bumpy ride. One of the bumpiest approaches I ever made was through one of these shear zones. Ground wind was reported by the tower to be 10 kts from the east. On a 2 mile final, my GPS was telling me I had 40 kts from the north at 1,500 ft. AGL. That last 1,500 ft. was a hell of a wild ride, but when I touched down, the wind was blowing lightly from the east. Just as advertised. John Galban=====N4BQ (PA28-180) |
#4
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Jay Honeck wrote:
experienced extremely high winds and record COLD temps. In fact, we broke .... Initially after departure all was smooth -- but by 1500 feet we were getting bounced pretty good. By 3000, we were inside a popcorn popper. Mary A cold air mass and a strong heating sun gives you the best thermals. That's why spring is the best season for soaring. Go to your nearest glider school and buy a cross country flight or two, and you'll understand this a lot better. Danger is, though, that you'll get hooked and sell your engine. Stefan |
#5
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"Jay Honeck" wrote in message
news:sZaee.56223$c24.36319@attbi_s72... [...] I suppose after all the unsettled weather we've had the atmosphere is still stirred up -- but no one standing on the ground would EVER have guessed what was brewing and burbling just a few thousand feet overhead. "No one"? That's obviously false. In fact, the conditions you describe sound like there was a reasonably decent temperature inversion, creating nice, calm stable air near the ground. Of course, any movement of the air above that inversion is going to create shear and the turbulence that goes along with that. When you got your weather forecast, did you look at the winds aloft forecast? Did you compare the temperatures on the surface with those at the various altitudes in the winds aloft forecast? What were the wind speed, direction, and temperatures in the winds aloft forecast? Did you look at the pressure charts? Both for the surface as well as for higher altitudes (850mb for example)? What sort of pressure gradient existed? This can give you additional information to elaborate on the winds aloft forecast, or even to correct errors in it (depending on how recent the winds aloft forecast is versus the pressure charts). It may well be true that you will never understand wind, and it's certainly true that understanding wind is a non-trivial exercise. But to claim that no one could have predicted the conditions you experience, well...that seems just a bit silly to me. As far as the lack of a specific mention of turbulence in the weather briefing, remember that an airmet for turbulence is given only for moderate or above. Pilots (and especially passengers) of light aircraft consistently overestimate the intensity of turbulence, and it's entirely possible that the turbulence you experienced was not great enough to justify an airmet. Pete |
#6
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The wind can do strange things. I have an airdata computer that gives a
constant display on winds aloft. Once I was flying into 130kt heawind out of the East at FL290 with moderate turbulence. I asked for and recieved a descent to FL250 and the wind was 35kts out of the West. I would have thought it impossible. I have seen similiar shifts a few times but never 165kts of shear over 4,000' Mike MU-2 "Jay Honeck" wrote in message news:sZaee.56223$c24.36319@attbi_s72... Today, for the first time in weeks, dawned clear, cool, and calm. After a VERY early spring (with temps in the 80s for over a week), we have experienced extremely high winds and record COLD temps. In fact, we broke the record here on both Sunday and Monday... (Take THAT all you "global warming" pessimists!) When we got to the hangar, the air was as still as death. The wind sock hung limp as a rag, and AWOS was reporting winds variable at nuthin'... Flight service mentioned nothing about turbulence (for a change) -- so we taxied out to Rwy 25 in anticipation of a smooth ride to Clinton, IA... Initially after departure all was smooth -- but by 1500 feet we were getting bounced pretty good. By 3000, we were inside a popcorn popper. Mary climbed to 7500 feet before we penetrated the haze layer, and popped out into the clear, smooth air on top. It was a VERY uncomfortable ride until then -- and, of course, she had to descend back down through it to land. On the return flight a couple of hours later, it was even worse. Now we had heating of the day, with the sun on the dark, freshly plowed fields -- and the ride was wild, indeed. However, again it was smoother down LOW -- which was bizarre -- than it was in the middle altitudes. I suppose after all the unsettled weather we've had the atmosphere is still stirred up -- but no one standing on the ground would EVER have guessed what was brewing and burbling just a few thousand feet overhead. By all appearances, it was the perfect day to fly -- yet it was the most uncomfortable flight we've had in a good long time. -- Jay Honeck Iowa City, IA Pathfinder N56993 www.AlexisParkInn.com "Your Aviation Destination" |
#7
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Once I was flying into 130kt heawind out
of the East at FL290 with moderate turbulence. If I was flying into 130 kt headwind I'd reach my departure point before I reached my arrival point ![]() Tony Tony Roberts PP-ASEL VFR OTT Night Cessna 172H C-GICE |
#8
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tony roberts wrote:
If I was flying into 130 kt headwind I'd reach my departure point before I reached my arrival point ![]() Haha! ![]() -- Peter ----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
#9
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WOW!
Don't you guys even use the Winds page on the ADDS? Pick a day and time and step up and down the altitudes. It will tell you everything you want to know. Do the same thing with the temperatures at different altitudes. It's even color coded. Use the streamline display option. |
#10
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WOW!
Don't you guys even use the Winds page on the ADDS? Pick a day and time and step up and down the altitudes. It will tell you everything you want to know. Do the same thing with the temperatures at different altitudes. It's even color coded. Use the streamline display option. I do occasionally, but today was so picture-perfect (from the ground) that it never even dawned on me to look. As I mentioned to Mary, while we were getting tossed around: It's a good thing we can't see wind and turbulence (the way we can see rapids in a river) -- because if we could, humans would never have attempted flight. -- Jay Honeck Iowa City, IA Pathfinder N56993 www.AlexisParkInn.com "Your Aviation Destination" |
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