8 January 1998
MEMORANDUM FOR: Distribution list
FROM: W/NP12  Bradley A. Ballish
THROUGH: W/NP12  Cynthia Nelson
SUBJECT: Suspect VAD Winds
Very suspect VAD winds appear to be responible for the problem Chuck Vlcek
pointed out yesterday that some US upper air sites have winds that look suspect
relative to the global analysis winds. For the Final Global Model Run for 12Z
5 January 1999, there were 1019 zero windspeed VAD winds. Attached is a
sorted count on the station ID of all such zero VAD winds. There are many
others with light suspect winds, as well stronger winds that also look suspect.
I beleive we should we should shut off the VAD winds for the Global model
where there is currently very little QC of them. If the NGM and ETA models
have similar problems, the VAD winds should also be shutoff. I talked to
Stan Benjamin on the RUC useage. His report to Steve Lord is as follows:
Steve,
thanks for having Brad call and getting us in on
this discussion. I just talked w/ Dennis. The RUC
only uses the top quality VAD winds, but some of the zero winds
have the top quality flag. The RUC buddy check seems to be
catching maybe 75% of the zero winds, but not all. Since it
does seem to be a systematic problem, I agree w/ the idea of
changing the card for all VAD winds until we find out some
more info. In our buddy check, these zero winds can falsely
corroborate each other, so let's can 'em for now.
I'll send out some email to some NWS people who seems to
follow VAD winds some and see if they know anything.
Thanks again,
Stan
Distribution: W/NP12  W. Whitmore
W/NP2  S. Lord
W/NP22  G. DiMego
W/NP22  W. Collins
W/NP22  D. Keyser
W/NP23  H. Pan
R/E/FS1  S. Benjamin
CC: W/NP1  C. Staton
W/NP1x1  W. Baker
W/NP12  J. Irwin
W/NP12  C. Vlcek
No ID Data Examples Winds in knots
90 99566 P 812.0 QM 2 DIR OB/GES 0/333 SPD OB/GES 0/ 6 QM 2 DIF 6.3
77 99319 P 875.1 QM 2 DIR OB/GES 0/306 SPD OB/GES 0/ 25 QM 2 DIF 25.2
61 99530 P 843.1 QM 2 DIR OB/GES 0/244 SPD OB/GES 0/ 13 QM 2 DIF 13.0
57 99373 P 843.1 QM 2 DIR OB/GES 0/280 SPD OB/GES 0/ 27 QM 2 DIF 27.1
50 99310 P 875.1 QM 2 DIR OB/GES 0/313 SPD OB/GES 0/ 29 QM 2 DIF 28.7
49 99533 P 724.3 QM 2 DIR OB/GES 0/346 SPD OB/GES 0/ 10 QM 2 DIF 10.2
46 99357 P 812.0 QM 2 DIR OB/GES 0/268 SPD OB/GES 0/ 7 QM 2 DIF 6.8
44 99389 P 908.2 QM 2 DIR OB/GES 0/240 SPD OB/GES 0/ 19 QM 2 DIF 19.2
43 99549 P 875.1 QM 2 DIR OB/GES 0/263 SPD OB/GES 0/ 15 QM 2 DIF 14.9
42 99827 P 843.1 QM 2 DIR OB/GES 0/258 SPD OB/GES 0/ 14 QM 2 DIF 13.5
39 99526 P 843.1 QM 2 DIR OB/GES 0/281 SPD OB/GES 0/ 15 QM 2 DIF 14.6
28 99539 P 843.1 QM 2 DIR OB/GES 0/262 SPD OB/GES 0/ 10 QM 2 DIF 10.4
28 99362 P 942.1 QM 2 DIR OB/GES 0/332 SPD OB/GES 0/ 17 QM 2 DIF 16.5
25 99555 P 843.1 QM 2 DIR OB/GES 0/313 SPD OB/GES 0/ 9 QM 2 DIF 9.1
22 99557 P 908.2 QM 2 DIR OB/GES 0/222 SPD OB/GES 0/ 30 QM 2 DIF 30.1
22 99556 P 781.8 QM 2 DIR OB/GES 0/331 SPD OB/GES 0/ 4 QM 2 DIF 4.0
22 99528 P 942.1 QM 2 DIR OB/GES 0/299 SPD OB/GES 0/ 24 QM 2 DIF 24.4
22 99396 P 875.1 QM 2 DIR OB/GES 0/360 SPD OB/GES 0/ 4 QM 2 DIF 4.3
21 99512 P 812.0 QM 2 DIR OB/GES 0/285 SPD OB/GES 0/ 21 QM 2 DIF 21.3
19 99504 P 843.1 QM 2 DIR OB/GES 0/253 SPD OB/GES 0/ 17 QM 2 DIF 16.8
18 99500 P 752.7 QM 2 DIR OB/GES 0/243 SPD OB/GES 0/ 2 QM 2 DIF 2.2
18 99323 P 875.1 QM 2 DIR OB/GES 0/281 SPD OB/GES 0/ 17 QM 2 DIF 17.0
15 99537 P 752.7 QM 2 DIR OB/GES 0/310 SPD OB/GES 0/ 27 QM 2 DIF 26.6
13 99312 P 781.8 QM 2 DIR OB/GES 0/291 SPD OB/GES 0/ 19 QM 2 DIF 19.3
12 99511 P 875.1 QM 2 DIR OB/GES 0/356 SPD OB/GES 0/ 3 QM 2 DIF 2.5
12 99371 P 942.1 QM 2 DIR OB/GES 0/251 SPD OB/GES 0/ 19 QM 2 DIF 19.1
12 99349 P 843.1 QM 2 DIR OB/GES 0/265 SPD OB/GES 0/ 16 QM 2 DIF 15.8
12 99341 P 875.1 QM 2 DIR OB/GES 0/305 SPD OB/GES 0/ 12 QM 2 DIF 11.6
10 99564 P 752.7 QM 2 DIR OB/GES 0/347 SPD OB/GES 0/ 8 QM 2 DIF 7.8
10 99518 P 781.8 QM 2 DIR OB/GES 0/310 SPD OB/GES 0/ 17 QM 2 DIF 17.0
9 99342 P 977.1 QM 2 DIR OB/GES 0/281 SPD OB/GES 0/ 6 QM 2 DIF 5.9
8 99398 P 781.8 QM 2 DIR OB/GES 0/277 SPD OB/GES 0/ 17 QM 2 DIF 17.0
8 99381 P 843.1 QM 2 DIR OB/GES 0/270 SPD OB/GES 0/ 17 QM 2 DIF 16.5
8 99380 P 875.1 QM 2 DIR OB/GES 0/344 SPD OB/GES 0/ 6 QM 2 DIF 6.3
7 99546 P 752.7 QM 2 DIR OB/GES 0/313 SPD OB/GES 0/ 27 QM 2 DIF 27.1
7 99334 P 843.1 QM 2 DIR OB/GES 0/283 SPD OB/GES 0/ 24 QM 2 DIF 24.1
5 99543 P 875.1 QM 2 DIR OB/GES 0/256 SPD OB/GES 0/ 15 QM 2 DIF 14.8
5 99521 P 875.1 QM 2 DIR OB/GES 0/275 SPD OB/GES 0/ 19 QM 2 DIF 18.9
5 99313 P 752.7 QM 2 DIR OB/GES 0/273 SPD OB/GES 0/ 17 QM 2 DIF 16.9
4 99548 P 908.2 QM 2 DIR OB/GES 0/217 SPD OB/GES 0/ 24 QM 2 DIF 23.7
4 99506 P 875.1 QM 2 DIR OB/GES 0/224 SPD OB/GES 0/ 23 QM 2 DIF 23.1
2 99542 P 977.1 QM 2 DIR OB/GES 0/154 SPD OB/GES 0/ 7 QM 2 DIF 7.1
2 99350 P 781.8 QM 2 DIR OB/GES 0/298 SPD OB/GES 0/ 19 QM 2 DIF 19.1
2 99335 P 724.3 QM 2 DIR OB/GES 0/307 SPD OB/GES 0/ 38 QM 2 DIF 38.0
1 99825 P 843.1 QM 2 DIR OB/GES 0/253 SPD OB/GES 0/ 30 QM 2 DIF 29.6
1 99382 P 942.1 QM 2 DIR OB/GES 0/313 SPD OB/GES 0/ 12 QM 2 DIF 12.2
1 99359 P 812.0 QM 2 DIR OB/GES 0/264 SPD OB/GES 0/ 12 QM 2 DIF 12.1
1 99345 P 875.1 QM 2 DIR OB/GES 0/240 SPD OB/GES 0/ 22 QM 2 DIF 21.5
