Soaring Guidance
Issued by NWS Pueblo, CO

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000
UXUS97 KPUB 221300
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0659 MDT Friday, September 22, 2017

This forecast is for Friday, September 22, 2017:

If the trigger temperature of 66.4 F/19.1 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 779 ft/min (4.0 m/s)
   Maximum height of thermals.................. 16853 ft MSL (9252 ft AGL)

Forecast maximum temperature................... 79.0 F/26.6 C
Time of trigger temperature.................... 0930 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 14266 ft MSL (6665 ft AGL)
Thermal soaring outlook for Saturday 09/23..... Fair

Wave Soaring Index............................. Not available

Remarks...

Sunrise/Sunset.................... 06:47:28 / 18:56:15 MDT
Total possible sunshine........... 12 hr 8 min 47 sec (728 min 47 sec)
Altitude of sun at 12:51:52 MDT... 51.01 degrees

Upper air data from numerical model forecast valid on 09/22/2017 at 0600 MDT

Freezing level.................. 15911 ft MSL (8310 ft AGL)
Convective condensation level... 18970 ft MSL (11369 ft AGL)
Lifted condensation level....... 18489 ft MSL (10888 ft AGL)
Lifted index.................... -1.1
K index......................... -8.0

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -66.4 -87.5   225   34   17   2.7   1.5      M     M       M      M    M
 45000  -61.6 -78.9   225   39   20   5.0   2.7      M     M       M      M    M
 40000  -54.1 -65.4   235   38   20   6.0   3.3      M     M       M      M    M
 38000  -50.3 -58.5   235   38   20   6.3   3.5      M     M       M      M    M
 36000  -46.0 -50.8   230   38   20   6.4   3.5      M     M       M      M    M
 34000  -41.6 -42.9   230   36   19   7.7   4.2      M     M       M      M    M
 32000  -36.9 -34.4   230   34   18   7.7   4.2      M     M       M      M    M
 30000  -31.9 -25.4   220   28   14   8.6   4.7   36.6  97.9     8.2      M    M
 29000  -29.3 -20.7   215   24   12   8.6   4.7   36.2  97.2     8.0      M    M
 28000  -26.8 -16.2   205   20   11   8.9   4.9   35.9  96.6     7.8      M    M
 27000  -24.7 -12.5   205   21   11   6.3   3.5   34.8  94.7     7.0      M    M
 26000  -22.8  -9.0   205   23   12   6.4   3.5   33.5  92.3     6.0      M    M
 25000  -20.9  -5.6   205   25   13   6.4   3.5   32.3  90.2     5.1      M    M
 24000  -18.8  -1.8   205   26   14   7.9   4.3   31.4  88.5     4.3      M    M
 23000  -16.4   2.5   205   26   13   7.9   4.3   30.7  87.2     3.8      M    M
 22000  -14.1   6.6   205   26   13   7.9   4.3   30.1  86.1     3.3      M    M
 21000  -11.1  12.0   205   25   13   7.8   4.3   29.2  84.6     2.6      M    M
 20000   -8.8  16.2   205   24   12   7.8   4.3   28.5  83.4     2.1      M    M
 19500   -7.6  18.3   205   24   12   7.8   4.3   28.2  82.8     1.8      M    M
 19000   -6.4  20.5   205   23   12   7.6   4.2   28.0  82.3     1.6      M    M
 18500   -5.3  22.5   205   23   12   7.5   4.1   27.6  81.6     1.2      M    M
 18000   -4.2  24.4   205   22   12   7.5   4.1   27.2  80.9     0.9      M    M
 17500   -3.1  26.4   205   22   11   6.8   3.7   26.7  80.1     0.5      M    M
 17000   -2.1  28.2   205   21   11   6.8   3.8   26.3  79.3     0.1      M    M
 16500   -1.1  30.0   205   21   11   6.7   3.7   25.8  78.4    -0.3    742  3.8
 16000   -0.1  31.8   205   20   11   6.6   3.6   25.3  77.5    -0.9    698  3.5
 15500    0.9  33.6   205   20   10   6.4   3.5   24.7  76.5    -1.4    655  3.3
 15000    1.7  35.1   210   20   10   5.3   2.9   24.1  75.4    -2.0    615  3.1
 14500    2.5  36.5   210   20   10   5.5   3.0   23.4  74.1    -2.7    577  2.9
 14000    3.2  37.8   215   20   10   5.3   2.9   22.7  72.8    -3.4    539  2.7
 13500    4.0  39.2   220   20   11   5.3   2.9   22.0  71.6    -4.2    503  2.6
 13000    4.8  40.6   220   21   11   7.5   4.1   21.4  70.6    -4.8    463  2.4
 12500    5.6  42.1   225   21   11   5.1   2.8   20.9  69.6    -5.5    424  2.2
 12000    6.3  43.3   225   21   11   6.6   3.6   20.2  68.4    -6.3    388  2.0
 11750    6.8  44.2   225   21   11   7.9   4.4   20.0  68.1    -6.5    366  1.9
 11500    7.4  45.3   225   20   10   8.2   4.5   19.9  67.8    -6.7    342  1.7
 11250    7.9  46.2   225   20   10   8.8   4.8   19.8  67.6    -6.9    317  1.6
 11000    8.5  47.3   230   19   10   7.8   4.3   19.7  67.5    -7.1    292  1.5
 10750    9.0  48.2   230   18    9   6.9   3.8   19.5  67.1    -7.3    269  1.4
 10500    9.6  49.3   230   18    9   7.2   4.0   19.3  66.7    -7.5    246  1.3
 10250   10.1  50.2   230   17    9   7.9   4.3   19.1  66.4    -7.7    222  1.1
 10000   10.7  51.3   235   17    9   7.0   3.9   19.0  66.2    -7.9    198  1.0
  9750   11.1  52.0   235   16    8   5.8   3.2   18.7  65.6    -8.2    177  0.9
  9500   11.6  52.9   240   16    8   6.3   3.5   18.4  65.1    -8.5    156  0.8
  9250   12.0  53.6   240   15    8   5.2   2.8   18.1  64.6    -8.8    135  0.7
  9000   12.4  54.3   245   14    7   5.2   2.9   17.7  63.9    -9.1    115  0.6
  8750   12.9  55.2   245   12    6   6.0   3.3   17.4  63.4    -9.4     94  0.5
  8500   13.4  56.1   245   11    6   6.7   3.7   17.2  62.9    -9.7     73  0.4
  8250   13.8  56.8   245   10    5   2.9   1.6   16.9  62.4   -10.0     51  0.3
  8000   13.6  56.5   240    9    4 -10.4  -5.7   15.9  60.6   -11.0     50  0.3
  7750   12.4  54.3   240    6    3 -20.5 -11.3   13.9  57.1   -12.9     79  0.4
  7500      M     M     M    M    M     M     M      M     M       M      M    M
  7250      M     M     M    M    M     M     M      M     M       M      M    M
  7000      M     M     M    M    M     M     M      M     M       M      M    M
  6750      M     M     M    M    M     M     M      M     M       M      M    M

 * * * * * * Numerical weather prediction model forecast data valid * * * * * *

           09/22/2017 at 0900 MDT          |       09/22/2017 at 1200 MDT
                                           |
CAPE...     0.0    LI...       +3.8        | CAPE...    +7.0    LI...       +2.2
CINH...     0.0    K Index...  -9.6        | CINH...   -78.5    K Index...  -0.7
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -64.9 -84.8  220  31 16   2.3   1.3 | -65.7 -86.3  215  30 16   3.0   1.7
 45000 -60.8 -77.4  225  41 21   4.5   2.5 | -60.8 -77.4  225  46 24   4.1   2.3
 40000 -53.9 -65.0  230  45 23   5.5   3.0 | -54.6 -66.3  225  51 26   5.8   3.2
 38000 -49.8 -57.6  230  45 23   6.1   3.4 | -49.9 -57.8  225  50 26   6.9   3.8
 36000 -46.1 -51.0  225  44 23   6.2   3.4 | -45.8 -50.4  220  49 25   6.9   3.8
 34000 -41.7 -43.1  225  42 22   7.7   4.2 | -41.4 -42.5  220  46 24   7.5   4.1
 32000 -37.1 -34.8  225  39 20   7.7   4.2 | -36.8 -34.2  215  44 23   7.6   4.2
 30000 -32.3 -26.1  215  33 17   8.1   4.5 | -32.1 -25.8  215  40 21   8.1   4.4
 29000 -29.9 -21.8  210  30 15   8.1   4.5 | -29.6 -21.3  215  38 19   8.1   4.4
 28000 -27.5 -17.5  205  26 14   8.2   4.5 | -27.2 -17.0  210  36 18   8.2   4.5
 27000 -25.3 -13.5  205  26 14   6.7   3.7 | -25.0 -13.0  210  34 18   7.0   3.9
 26000 -23.3  -9.9  205  28 14   6.7   3.7 | -22.9  -9.2  210  34 17   7.0   3.9
 25000 -21.3  -6.3  205  29 15   6.8   3.7 | -20.8  -5.4  210  33 17   7.0   3.9
 24000 -19.2  -2.6  205  30 15   7.8   4.3 | -18.8  -1.8  210  32 17   6.1   3.4
 23000 -16.9   1.6  205  29 15   7.8   4.3 | -16.9   1.6  210  31 16   6.2   3.4
 22000 -13.9   7.0  200  28 14   7.7   4.2 | -14.7   5.5  205  29 15   6.2   3.4
 21000 -11.5  11.3  200  27 14   8.0   4.4 | -12.3   9.9  205  28 14   8.6   4.7
 20000  -9.1  15.6  200  27 14   8.0   4.4 |  -9.7  14.5  205  26 14   8.6   4.7
 19500  -7.9  17.8  200  26 14   8.0   4.4 |  -8.4  16.9  205  26 13   8.5   4.7
 19000  -6.7  19.9  200  26 13   7.5   4.1 |  -7.1  19.2  205  25 13   8.1   4.4
 18500  -5.6  21.9  205  25 13   7.2   4.0 |  -5.9  21.4  210  26 13   7.8   4.3
 18000  -4.5  23.9  205  25 13   7.3   4.0 |  -4.8  23.4  210  26 13   8.1   4.4
 17500  -3.5  25.7  205  24 13   6.4   3.5 |  -3.8  25.2  215  26 14   4.6   2.5
 17000  -2.6  27.3  205  24 12   6.5   3.5 |  -3.1  26.4  215  26 14   4.9   2.7
 16500  -1.6  29.1  210  24 12   5.7   3.1 |  -2.4  27.7  220  26 13   4.1   2.3
 16000  -0.9  30.4  210  23 12   5.1   2.8 |  -1.9  28.6  220  26 13   3.6   2.0
 15500  -0.1  31.8  215  23 12   5.1   2.8 |  -1.4  29.5  225  26 13   3.8   2.1
 15000   0.5  32.9  215  23 12   4.3   2.4 |  -0.9  30.4  230  25 13   4.7   2.6
 14500   1.1  34.0  220  22 12   4.4   2.4 |  -0.2  31.6  230  25 13   4.7   2.6
 14000   1.8  35.2  225  22 12   4.9   2.7 |   0.5  32.9  230  25 13   6.2   3.4
 13500   2.4  36.3  230  23 12   4.8   2.7 |   1.3  34.3  230  24 12   6.0   3.3
 13000   3.2  37.8  230  23 12   7.6   4.2 |   2.3  36.1  230  23 12   8.7   4.8
 12500   4.2  39.6  230  22 11   6.1   3.4 |   3.3  37.9  230  21 11   6.6   3.6
 12000   5.0  41.0  235  20 10   7.1   3.9 |   4.3  39.7  230  18  9   7.4   4.0
 11750   5.6  42.1  230  19 10   7.7   4.2 |   4.8  40.6  225  17  9   8.0   4.4
 11500   6.1  43.0  230  17  9   7.3   4.0 |   5.5  41.9  225  16  8   9.1   5.0
 11250   6.6  43.9  225  16  8   7.3   4.0 |   6.1  43.0  225  15  8   9.8   5.4
 11000   7.1  44.8  225  14  7   7.1   3.9 |   6.8  44.2  220  14  7   8.5   4.6
 10750   7.6  45.7  225  13  7   6.9   3.8 |   7.4  45.3  215  13  7   7.1   3.9
 10500   8.0  46.4  220  13  7   7.0   3.8 |   7.9  46.2  210  12  6   8.7   4.8
 10250   8.5  47.3  225  13  6   7.1   3.9 |   8.7  47.7  210  12  6  12.3   6.7
 10000   9.0  48.2  225  12  6   6.1   3.4 |   9.6  49.3  205  11  6  10.8   5.9
  9750   9.4  48.9  225  12  6   5.4   2.9 |  10.3  50.5  200  11  6   8.6   4.7
  9500   9.8  49.6  230  12  6   5.2   2.8 |  11.0  51.8  200  11  5   8.5   4.7
  9250  10.2  50.4  230  12  6   6.7   3.7 |  11.6  52.9  195  10  5  10.9   6.0
  9000  10.8  51.4  230  10  5   8.3   4.6 |  12.6  54.7  190  10  5  11.6   6.4
  8750  11.4  52.5  230   9  5   7.7   4.2 |  13.3  55.9  190  10  5   9.7   5.3
  8500  12.0  53.6  225   8  4   8.0   4.4 |  14.0  57.2  190  10  5   9.8   5.4
  8250  12.6  54.7  220   7  4   7.4   4.1 |  14.8  58.6  190  10  5  11.4   6.2
  8000  13.2  55.8  215   6  3  10.7   5.9 |  15.9  60.6  190  10  5  18.8  10.3
  7750  14.3  57.7  205   5  3  17.6   9.6 |  17.6  63.7  185   9  5  25.7  14.1
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           09/22/2017 at 1500 MDT          |       09/22/2017 at 1800 MDT
                                           |
CAPE...   +83.4    LI...        0.0        | CAPE...   +65.4    LI...       -1.4
CINH...    -2.9    K Index...  +7.7        | CINH...   -12.3    K Index... +24.1
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -65.7 -86.3  225  35 18   3.6   2.0 | -64.5 -84.1  225  32 16   3.6   2.0
 45000 -60.3 -76.5  225  50 25   3.7   2.1 | -59.3 -74.7  230  46 24   2.9   1.6
 40000 -54.7 -66.5  225  56 29   5.2   2.9 | -55.0 -67.0  225  49 25   4.1   2.3
 38000 -50.2 -58.4  220  54 28   6.7   3.7 | -50.8 -59.4  225  49 25   6.2   3.4
 36000 -46.2 -51.2  220  52 27   6.7   3.7 | -47.1 -52.8  220  49 25   6.2   3.4
 34000 -41.8 -43.2  220  49 25   7.6   4.2 | -42.7 -44.9  220  48 24   7.9   4.3
 32000 -37.2 -35.0  215  46 24   7.6   4.2 | -38.0 -36.4  220  45 23   7.9   4.3
 30000 -32.6 -26.7  215  43 22   7.7   4.2 | -33.1 -27.6  220  42 22   8.3   4.5
 29000 -30.3 -22.5  215  40 21   7.7   4.2 | -30.6 -23.1  220  41 21   8.3   4.5
 28000 -28.0 -18.4  215  38 20   7.7   4.2 | -28.1 -18.6  215  40 21   8.3   4.6
 27000 -25.8 -14.4  215  37 19   7.4   4.0 | -25.9 -14.6  215  39 20   7.1   3.9
 26000 -23.6 -10.5  215  36 19   7.4   4.0 | -23.8 -10.8  215  38 20   7.1   3.9
 25000 -21.4  -6.5  215  35 18   7.3   4.0 | -21.6  -6.9  215  37 19   7.1   3.9
 24000 -19.3  -2.7  215  34 18   6.0   3.3 | -19.7  -3.5  215  36 19   5.0   2.8
 23000 -17.5   0.5  215  32 17   6.2   3.4 | -18.2  -0.8  215  35 18   5.2   2.8
 22000 -15.3   4.5  210  30 16   6.3   3.4 | -16.3   2.7  215  34 17   5.2   2.8
 21000 -13.1   8.4  210  30 15   7.5   4.1 | -14.5   5.9  215  32 17   6.7   3.7
 20000 -10.8  12.6  210  29 15   7.5   4.1 | -12.5   9.5  215  31 16   6.8   3.7
 19500  -9.7  14.5  210  29 15   7.5   4.1 | -11.5  11.3  215  31 16   6.8   3.8
 19000  -8.6  16.5  215  29 15   6.9   3.8 | -10.5  13.1  215  30 15   7.3   4.0
 18500  -7.6  18.3  215  28 14   6.4   3.5 |  -9.4  15.1  215  29 15   7.8   4.3
 18000  -6.7  19.9  215  27 14   6.5   3.6 |  -8.3  17.1  210  28 14   7.9   4.3
 17500  -5.9  21.4  215  27 14   4.7   2.6 |  -7.2  19.0  210  26 14   7.7   4.2
 17000  -5.2  22.6  220  27 14   5.0   2.8 |  -6.1  21.0  205  25 13   7.8   4.3
 16500  -4.5  23.9  220  27 14   5.7   3.1 |  -5.0  23.0  205  23 12   8.4   4.6
 16000  -3.7  25.3  220  25 13   6.2   3.4 |  -3.7  25.3  200  22 11   8.9   4.9
 15500  -2.9  26.8  215  24 12   6.6   3.6 |  -2.4  27.7  200  21 11   9.0   4.9
 15000  -1.9  28.6  215  22 11   8.3   4.5 |  -1.1  30.0  195  21 11   9.1   5.0
 14500  -0.7  30.7  210  20 10   8.2   4.5 |   0.3  32.5  195  20 10   9.1   5.0
 14000   0.5  32.9  210  19 10   8.8   4.8 |   1.7  35.1  190  20 10   9.5   5.2
 13500   1.8  35.2  205  18  9   8.6   4.7 |   3.1  37.6  190  20 10   9.0   5.0
 13000   3.2  37.8  205  17  9  10.6   5.8 |   4.7  40.5  190  19 10  12.0   6.6
 12500   4.5  40.1  205  16  8   8.5   4.7 |   6.1  43.0  190  19 10   7.6   4.1
 12000   5.8  42.4  200  16  8   8.8   4.8 |   7.3  45.1  190  19 10   8.9   4.9
 11750   6.5  43.7  200  15  8   9.2   5.1 |   8.0  46.4  190  19 10   9.4   5.2
 11500   7.2  45.0  200  14  7   9.8   5.4 |   8.6  47.5  190  18  9   8.9   4.9
 11250   7.9  46.2  195  14  7  10.1   5.5 |   9.3  48.7  185  18  9   8.8   4.9
 11000   8.7  47.7  195  13  7   9.0   4.9 |  10.0  50.0  185  18  9   8.8   4.8
 10750   9.3  48.7  190  13  7   7.7   4.2 |  10.6  51.1  185  17  9   8.6   4.7
 10500   9.9  49.8  190  12  6   9.3   5.1 |  11.3  52.3  185  17  9   9.2   5.0
 10250  10.7  51.3  190  12  6  12.3   6.7 |  12.0  53.6  185  17  9  10.4   5.7
 10000  11.6  52.9  190  12  6  10.8   5.9 |  12.8  55.0  180  16  8   9.8   5.4
  9750  12.3  54.1  185  12  6   9.1   5.0 |  13.4  56.1  180  16  8   9.2   5.1
  9500  13.0  55.4  185  12  6   8.9   4.9 |  14.1  57.4  180  16  8   9.0   4.9
  9250  13.7  56.7  185  12  6  11.4   6.3 |  14.8  58.6  180  15  8  10.4   5.7
  9000  14.6  58.3  185  12  6  11.7   6.4 |  15.6  60.1  180  15  8  10.6   5.8
  8750  15.3  59.5  185  11  6   9.3   5.1 |  16.4  61.5  180  15  8   9.1   5.0
  8500  16.1  61.0  185  11  6   9.5   5.2 |  17.1  62.8  175  14  7   9.7   5.3
  8250  16.8  62.2  185  11  6  11.0   6.1 |  17.8  64.0  175  14  7   8.8   4.8
  8000  17.9  64.2  185  11  6  18.0   9.9 |  18.4  65.1  175  13  7   8.5   4.6
  7750  19.4  66.9  180  10  5  24.1  13.2 |  19.0  66.2  175  10  5  10.1   5.5
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

This product is issued twice per day, once by approximately 0630 MST/0730 MDT
(1330 UTC).  It is not continuously monitored nor updated after its initial
issuance.

The information contained herein is based on rawinsonde observation and/or
numerical weather prediction model data taken near the Air Force Academy
in Colorado Springs, Colorado at

                   North Latitude:  38 deg 58 min 48.000 sec
                   West Longitude: 104 deg 49 min 12.000 sec
                   Elevation: 6572 feet (2003 meters)

and may not be representative of other areas along the Front Range of the
Colorado Rocky Mountains.  Note that some elevations in numerical weather
prediction models differ from actual station elevations, which can lead to
data which appear to be below ground.  Erroneous data such as these should
not be used.

The content and format of this report as well as the issuance times are subject
to change without prior notice.  Comments and suggestions are welcome and should
be directed to one of the addresses or phone numbers shown at the bottom of this
page.  To expedite a response to comments, be sure to mention your interest in
the soaring forecast.

DEFINITIONS:

CAPE (Convective Available Potential Energy) - An integrated measure of the
     energy available for convective development, also known as the positive
     area on a thermodynamic diagram.  Units are Joules per kilogram.  Larger
     values are indicative of greater instability and the possibility of
     stronger convective activity, including thunderstorms.  Values around or
     greater than 1000 suggest the possibility of severe weather should
     convective activity develop.

CIN (Convective Inhibition) - An integrated measure of the amount of energy
     needed to initiate convective activity, also known as the negative area on
     a thermodynamic diagram.  Units are Joules per kilogram.  The more negative
     this number, the more energy is required to initiate convection.  This
     inhibitive energy can be overcome through surface heating, cooling aloft,
     lifting mechanisms (orographic, frontal, gravity waves, etc.)

Convective Condensation Level - The height to which an air parcel possessing the
     average saturation mixing ratio in the lowest 4000 feet of the airmass,
     if heated sufficiently from below, will rise dry adiabatically until it
     just becomes saturated.  It estimates the base of cumulus clouds that are
     produced by surface heating only.

Convection Temperature (ConvectionT) - The surface temperature required to make
     the airmass dry adiabatic up to the given level.  It can be considered a
     "trigger temperature" for that level.

Freezing Level - The height where the temperature is zero degrees Celsius.

Height of Stable Layer - The height (between 12,000 and 18,000 feet above
     mean sea level) where the smallest lapse rate exists.  The location and
     existence of this feature is important in the generation of mountain
     waves.

K Index - A measure of stability which combines the temperature difference
     between approximately 5,000 and 18,000 feet above the surface, the amount
     of moisture at approximately 5,000 feet above the surface, and a measure
     of the dryness at approximately 10,000 feet above the surface.  Larger
     positive numbers indicate more instability and a greater likelihood of
     thunderstorm development.  One interpretation of K index values regarding
     soaring in the western United States is given in WMO Technical Note 158
     and is reproduced in the following table:

          below -10    no or weak thermals
           -10 to 5    dry thermals or 1/8 cumulus with moderate thermals
            5 to 15    good soaring conditions
           15 to 20    good soaring conditions with occasional showers
           20 to 30    excellent soaring conditions, but increasing
                       probability of showers and thunderstorms
           above 30    more than 60 percent probability of thunderstorms

Lapse Rate - The change with height of the temperature. Negative values indicate
     inversions.

Lifted Condensation Level - The height to which an air parcel possessing the
     average dew point in the lowest 4000 feet of the airmass and the forecast
     maximum temperature must be lifted dry adiabatically to attain saturation.

Lifted Index (LI) - The difference between the environmental temperature at a
     level approximately 18,000 feet above the surface and the temperature of
     an air parcel lifted dry adiabatically from the surface to its lifted
     condensation level and then pseudoadiabatically thereafter to this same
     level.  The parcel`s initial temperature is the forecast maximum
     temperature and its dew point is the average dew point in the lowest 4000
     feet of the airmass.  Negative values are indicative of instability with
     positive values showing stable conditions.

Lift Rate - An experimental estimate of the strength of thermals.  It is
     computed the same way as the maximum rate of lift but uses the actual
     level rather than the maximum height of thermals in the calculation.
     Also, none of the empirical adjustments based on cloudiness and K-index
     are applied to these calculations.

Maximum Height of Thermals - The height where the dry adiabat through the
     forecast maximum temperature intersects the environmental temperature.

Maximum Rate of Lift - An estimate of the maximum strength of thermals.  It
     is computed from an empirical formula which combines the expected maximum
     height of thermals with the difference in the environmental temperatures
     between the maximum height of thermals and the temperature 4,000 feet
     above the ground.  After this computation, further empirical adjustments
     are made based on the value of the K-index and the amount and opacity of
     middle and high level cloudiness expected between the time of trigger
     temperature and the time of overdevelopment.

Middle/High Clouds - The amount and opacity of middle (altostratus, altocumulus)
     or high (cirrus, cirrostratus, cirrocumulus) clouds.  Broken means that
     between 60% and 90% of the sky is covered by the cloud, with overcast
     conditions occurring when more than 90% of the sky is covered by the cloud.
     Thin implies that the clouds are predominantly transparent, meaning that
     some sunlight is reaching the ground, in contrast to opaque which suggests
     that little sunlight is reaching the ground.

Potential Height of Wave - The minimum of the following two heights:
     1. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind direction changes by 30 degrees or more
     2. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind speed no longer increases with height

PVA/NVA - Positive vorticity advection (PVA)/negative vorticity advection (NVA)
     on the 500 millibar isobaric surface (approximately 18,000 feet above mean
     sea level).  Weak PVA has been shown to assist in mountain wave soaring.

Soaring Window - The time between the time the trigger temperature is reached
                 and the time of overdevelopment.

Thermal Index - The difference between the environmental temperature and the
     temperature at a particular level determined by following the dry adiabat
     through the forecast maximum temperature up to that level.  Negative values
     are indicative of thermal lift.

Thermal Soaring Index - An adjective rating (for sailplanes) based on the
     computed maximum rate of lift, and the wind speed and middle and high
     cloud cover expected during the soaring window (the time of the trigger
     temperature and the time of overdevelopment) according to the following:

                 Maximum rate of lift        Adjective Rating
                      >= 800 fpm                 Excellent
                 >= 400 and < 800 fpm              Good
                 >= 200 and < 400 fpm              Fair
                       < 200 fpm                   Poor

Time of Overdevelopment - The time one or more of the following phenomena,
     which essentially shut off thermal lift, is expected to occur:
     1. formation of broken to overcast convective cloud cover
     2. formation of scattered to numerous downbursts
     3. initiation of widespread precipitation

Time of Trigger Temperature - The time the surface temperature is expected to
     reach the trigger temperature.

Trigger Temperature - The surface temperature required to make the first 4000
     feet of the atmosphere dry adiabatic.

Wave Soaring Index - An empirical, adjective rating (for sailplanes) which
     attempts to combine a variety of phenomena important in mountain wave
     soaring into a single index number.  Objective points are assigned to
     these phenomena: wind speed and direction at 14,000 ft MSL, the static
     stability in the 12,000-18,000 ft MSL layer, the wind speed gradient above
     the stable layer, jet stream location and frontal and upper trough
     movements.

042613



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