Originally posted by brocket99
Just so everyone knows:

Clear blue skies all day today in Seattle, WA.

Thanks brocket, will check out the upper weather conditions in Washington when the 23 z flight goes up.

[edit on 24/8/2009 by OzWeatherman]

This ones for Brocket in Seattle

300.0 9450 -39.5 -52.5 24 0.10 215 50 329.6 330.0 329.6
298.0 9496 -39.9 -51.9 27 0.11 215 50 329.6 330.1 329.7
262.0 10361 -47.9 -58.9 27 0.05 211 54 330.3 330.5 330.3
254.0 10565 -48.1 -60.1 24 0.05 210 55 332.9 333.1 332.9
250.0 10670 -48.9 -60.9 23 0.04 210 55 333.2 333.4 333.2
227.0 11296 -54.3 -65.3 25 0.03 210 56 334.3 334.4 334.3
216.0 11613 -55.3 -66.3 24 0.02 210 57 337.5 337.6 337.5
206.0 11914 -57.5 -68.5 23 0.02 210 58 338.7 338.8 338.7
200.0 12100 -58.3 -69.3 23 0.02 210 58 340.3 340.4 340.3
192.0 12357 -58.5 -69.5 23 0.02 213 59 344.0 344.0 344.0
188.0 12489 -59.7 -70.7 23 0.01 215 60 344.1 344.2 344.1
187.8 12497 -59.6 -70.7 23 0.01 215 60 344.3 344.4 344.3
178.9 12802 -57.5 -69.2 21 0.02 215 43 352.6 352.7 352.6
175.0 12942 -56.5 -68.5 21 0.02 214 43 356.5 356.6 356.5
172.0 13051 -57.3 -69.3 20 0.02 214 43 356.9 357.0 356.9
158.0 13590 -56.5 -69.5 18 0.02 211 42 367.0 367.1 367.0
150.0 13920 -57.1 -70.1 18 0.02 210 41 371.5 371.6 371.5

Brocket confirmed that he never saw any contrails, only clear sky, the weather balloon data confirms it


[edit on 24/8/2009 by OzWeatherman]

After enough data is taken and observed, it might be an idea to predict whether or not the posters will see contrails that day or not.

Obviously we have to be honest, and the conditions have to be right...no normal cloud cover, but I think you're up for it.

Originally posted by brocket99
After enough data is taken and observed, it might be an idea to predict whether or not the posters will see contrails that day or not.

Obviously we have to be honest, and the conditions have to be right...no normal cloud cover, but I think you're up for it.

Yeah thats possible. The only problem is you have to also incorperate forecasting into it in case the weather changes rapidly, ie if a frontal system is approaching rapidly

Unbelievably clear skies in central PA today. I actually can't wait to go for my nightly run because the stars are so clear.

Finally, the humidity is gone and I can breath! Feels like fall is coming.

One contrail today. It was wispy and didn't stay for long at all.

Originally posted by SantaClaus
Unbelievably clear skies in central PA today. I actually can't wait to go for my nightly run because the stars are so clear.

Finally, the humidity is gone and I can breath! Feels like fall is coming.

One contrail today. It was wispy and didn't stay for long at all.

Yep, this pretty much confirms that observation for PA, observations from Pittsburgh

300.0 9590 -38.5 -62.5 6 0.03 35 46 331.0 331.1 331.0
286.0 9917 -41.5 -64.5 6 0.02 35 52 331.2 331.4 331.2
264.0 10457 -44.3 -66.3 7 0.02 35 63 334.8 334.9 334.8
255.8 10668 -45.8 -67.2 7 0.02 35 67 335.6 335.7 335.6
251.0 10793 -46.7 -67.8 7 0.02 35 67 336.1 336.2 336.1
250.0 10820 -46.9 -67.9 7 0.02 35 66 336.2 336.3 336.2
234.0 11257 -50.1 -69.1 9 0.01 34 52 337.8 337.8 337.8
225.0 11513 -51.1 -70.1 9 0.01 33 44 340.1 340.1 340.1
221.0 11630 -50.5 -69.5 9 0.01 32 40 342.7 342.8 342.7
213.0 11871 -51.9 -69.9 10 0.01 31 32 344.2 344.2 344.2
202.0 12215 -51.7 -70.7 8 0.01 30 21 349.7 349.8 349.7
200.0 12280 -52.1 -71.1 8 0.01 30 19 350.1 350.2 350.1
191.0 12577 -54.1 -72.1 9 0.01 2 13 351.5 351.6 351.5
185.0 12782 -53.5 -71.5 9 0.01 342 9 355.7 355.8 355.7
184.4 12802 -53.6 -71.5 9 0.01 340 9 355.9 356.0 355.9
172.0 13249 -54.9 -71.9 10 0.01 322 13 360.9 361.0 360.9

Here is another photo of the trails...



And here is one of the general cloud cover. Or at this point, the lack thereof.

Taken at about 7:00pm CST or 1900hrs.



Now that I look through my photos, I think that every cloud I saw this afternoon was the result of a contrail. The moisture must be up way up there.

Here are the local conditions on the ground...

74.6 °F
Clear
Humidity: 62%
Dew Point: 61 °F
Wind: 3.0 mphfrom the South
Wind Gust: 3.0 mph
Pressure: 29.73 in (Steady)
Heat Index: 77 °F
Visibility: 10.0 miles
UV: 0 out of 16
Clouds: Clear -
(Above Ground Level)

Looks like the wind has picked up from the south just a tad and brought the humidity up about 10%. More moisture. But still not much. There are virtually no clouds in the sky.

Originally posted by JayinAR

Looks like the wind has picked up from the south just a tad and brought the humidity up about 10%. More moisture. But still not much. There are virtually no clouds in the sky.

Yeah balloon data confirms that

Even the lower layers confirm that, although its quite moist at around 3000 feet, but an inversion is sitting there I think, trapping the mositure in

829.0 1769 19.0 -13.0 10 1.70 36 10 308.2 313.9 308.6
823.2 1829 18.6 -12.8 11 1.74 35 10 308.5 314.3 308.8
794.2 2134 16.7 -12.0 13 1.92 0 5 309.6 316.0 310.0
766.3 2438 14.8 -11.2 15 2.13 40 7 310.7 317.8 311.1
766.0 2442 14.8 -11.2 16 2.13 40 7 310.7 317.8 311.1
739.0 2743 13.5 -13.0 15 1.92 30 9 312.6 319.0 312.9
712.0 3056 12.2 -14.8 14 1.71 16 10 314.4 320.3 314.8
700.0 3198 11.2 -15.8 13 1.60 10 10 314.9 320.4 315.2
664.0 3636 8.2 -15.8 17 1.69 15 12 316.3 322.1 316.6
662.2 3658 8.0 -15.7 17 1.70 15 12 316.3 322.1 316.6
614.6 4267 2.4 -13.9 29 2.14 25 10 316.7 323.9 317.1
613.0 4288 2.2 -13.8 30 2.16 25 10 316.7 324.0 317.1
604.0 4407 2.2 -18.8 19 1.44 24 10 318.0 323.1 318.3
595.0 4528 1.4 -16.6 25 1.76 23 11 318.4 324.6 318.8