Soaring Guidance
Issued by NWS Pueblo, CO

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UXUS97 KPUB 211031
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Soaring Forecast
National Weather Service Pueblo, Colorado
0431 MDT Wednesday, September 21, 2016

This forecast is for Wednesday, September 21, 2016:

If the trigger temperature of 68.4 F/20.2 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 375 ft/min (1.9 m/s)
   Maximum height of thermals.................. 15556 ft MSL (8798 ft AGL)

Forecast maximum temperature................... 76.0 F/24.9 C
Time of trigger temperature.................... 1015 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 12742 ft MSL (5985 ft AGL)
Thermal soaring outlook for Thursday 09/22..... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:46:17 / 18:58:16 MDT
Total possible sunshine........... 12 hr 11 min 59 sec (731 min 59 sec)
Altitude of sun at 12:51:47 MDT... 51.37 degrees

Upper air data from numerical model forecast valid on 09/21/2016 at 0600 MDT

Freezing level.................. 15168 ft MSL (8410 ft AGL)
Convective condensation level... 17008 ft MSL (10250 ft AGL)
Lifted condensation level....... 15938 ft MSL (9180 ft AGL)
Lifted index.................... +1.9
K index......................... +25.0

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  -65.7 -86.3   270   39   20   2.6   1.4      M     M       M      M    M
 45000  -61.1 -78.0   260   49   25   3.6   2.0      M     M       M      M    M
 40000  -54.8 -66.6   245   51   26   8.2   4.5      M     M       M      M    M
 38000  -49.8 -57.6   240   48   25   8.3   4.6      M     M       M      M    M
 36000  -44.8 -48.6   235   45   23   8.2   4.5      M     M       M      M    M
 34000  -39.3 -38.7   230   35   18   9.2   5.1      M     M       M      M    M
 32000  -33.8 -28.8   225   25   13   9.1   5.0      M     M       M      M    M
 30000  -28.4 -19.1   235   27   14   7.7   4.2   41.8 107.2    13.4      M    M
 29000  -26.2 -15.2   240   30   15   7.7   4.2   41.1 105.9    12.9      M    M
 28000  -23.9 -11.0   245   32   16   7.0   3.8   40.4 104.7    12.5      M    M
 27000  -21.9  -7.4   250   32   17   6.9   3.8   39.2 102.5    11.7      M    M
 26000  -19.8  -3.6   250   32   17   7.0   3.8   38.2 100.7    10.9      M    M
 25000  -17.8  -0.0   255   33   17   6.9   3.8   37.2  99.0    10.3      M    M
 24000  -15.8   3.6   255   33   17   6.7   3.7   36.1  97.0     9.4      M    M
 23000  -13.8   7.2   255   33   17   6.8   3.7   35.0  95.0     8.5      M    M
 22000  -11.8  10.8   260   33   17   6.4   3.5   34.1  93.3     7.7      M    M
 21000  -10.3  13.5   255   32   16   5.1   2.8   32.4  90.3     6.3      M    M
 20000   -8.8  16.2   255   31   16   5.1   2.8   30.8  87.5     5.0      M    M
 19500   -8.1  17.4   255   31   16   5.0   2.7   30.1  86.1     4.3      M    M
 19000   -7.3  18.9   255   30   16   6.7   3.7   29.4  84.9     3.7      M    M
 18500   -6.3  20.7   255   30   16   6.7   3.7   28.9  84.0     3.2      M    M
 18000   -5.3  22.5   255   30   16   6.8   3.7   28.4  83.1     2.8      M    M
 17500   -4.4  24.1   255   31   16   6.9   3.8   27.9  82.2     2.3      M    M
 17000   -3.4  25.9   255   32   17   7.0   3.9   27.4  81.3     1.8      M    M
 16500   -2.4  27.7   250   33   17   5.8   3.2   26.9  80.4     1.3      M    M
 16000   -1.6  29.1   250   34   18   5.8   3.2   26.2  79.2     0.7      M    M
 15500   -0.8  30.6   245   35   18   5.7   3.2   25.6  78.0     0.1      M    M
 15000    0.5  32.9   245   36   19   5.7   3.1   24.6  76.2    -0.9    720  3.7
 14500    1.4  34.5   240   37   19   6.1   3.3   24.0  75.1    -1.5    679  3.5
 14000    2.3  36.1   240   37   19   6.2   3.4   23.4  74.1    -2.0    637  3.2
 13500    3.2  37.8   235   38   19   6.9   3.8   22.8  73.1    -2.5    594  3.0
 13000    4.3  39.7   230   37   19   7.5   4.1   22.4  72.4    -2.9    545  2.8
 12500    5.5  41.9   230   36   18   9.1   5.0   22.1  71.8    -3.2    497  2.5
 12000    6.7  44.1   230   34   17   6.7   3.7   21.9  71.4    -3.4    444  2.3
 11750    7.3  45.1   230   33   17   6.9   3.8   21.7  71.0    -3.6    420  2.1
 11500    7.8  46.0   225   32   17   8.3   4.5   21.5  70.7    -3.8    396  2.0
 11250    8.5  47.3   225   31   16   9.3   5.1   21.5  70.6    -3.8    368  1.9
 11000    9.2  48.6   225   31   16   8.0   4.4   21.4  70.5    -3.9    342  1.7
 10750    9.8  49.6   225   30   15   7.8   4.3   21.2  70.2    -4.1    316  1.6
 10500   10.4  50.7   225   29   15   8.3   4.5   21.1  69.9    -4.2    291  1.5
 10250   11.0  51.8   225   28   14   9.5   5.2   21.0  69.8    -4.3    264  1.3
 10000   11.7  53.1   225   27   14   8.7   4.8   21.0  69.8    -4.3    235  1.2
  9750   12.3  54.1   225   26   13   7.7   4.2   20.9  69.5    -4.5    210  1.1
  9500   12.9  55.2   225   25   13   8.1   4.4   20.7  69.3    -4.6    184  0.9
  9250   13.5  56.3   225   24   12   8.1   4.4   20.6  69.1    -4.7    159  0.8
  9000   14.1  57.4   225   23   12   8.2   4.5   20.5  68.8    -4.9    134  0.7
  8750   14.8  58.6   225   22   11   9.9   5.5   20.4  68.7    -5.0    107  0.5
  8500   15.5  59.9   225   21   11   8.4   4.6   20.4  68.8    -5.0     77  0.4
  8250   16.0  60.8   225   19   10   6.0   3.3   20.2  68.3    -5.2     55  0.3
  8000   16.4  61.5   225   17    9   6.0   3.3   19.9  67.8    -5.5     34  0.2
  7750   16.9  62.4   225   16    8   7.3   4.0   19.6  67.4    -5.8     13  0.1
  7500   17.3  63.1   225   14    7   0.2   0.1   19.4  66.9    -6.1      M    M
  7250   16.8  62.2   225   11    6  -7.9  -4.4   18.6  65.6    -6.9      1  0.0
  7000   16.4  61.5   225    8    4  -1.6  -0.9   17.9  64.2    -7.7      6  0.0
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           09/21/2016 at 0900 MDT          |       09/21/2016 at 1200 MDT
                                           |
K index... +24.9  LI... +273.9             | K index... +26.2  LI... +271.6
CAPE... 0.0  CIN... -11.1                  | CAPE... +165.7  CIN... -52.6
                                           |
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  270  36 18   3.0   1.6 | -65.9 -86.6  265  32 17   3.3   1.8
 45000 -60.4 -76.7  265  49 25   4.2   2.3 | -60.0 -76.0  265  47 24   4.6   2.5
 40000 -53.5 -64.3  250  48 25   7.4   4.1 | -52.8 -63.0  250  51 26   6.7   3.7
 38000 -49.0 -56.2  245  46 23   7.5   4.1 | -48.7 -55.7  250  50 26   6.7   3.7
 36000 -44.5 -48.1  235  44 23   7.4   4.1 | -44.7 -48.5  245  49 25   6.6   3.6
 34000 -39.7 -39.5  235  40 21   8.1   4.4 | -40.0 -40.0  240  44 22   8.0   4.4
 32000 -34.8 -30.6  240  37 19   7.9   4.3 | -35.2 -31.4  235  37 19   7.8   4.3
 30000 -29.6 -21.3  235  33 17   7.8   4.3 | -29.6 -21.3  240  38 20   8.6   4.7
 29000 -27.2 -17.0  235  32 16   7.9   4.3 | -27.0 -16.6  240  40 20   8.6   4.7
 28000 -24.9 -12.8  235  31 16   7.4   4.1 | -24.6 -12.3  240  41 21   6.7   3.7
 27000 -22.8  -9.0  240  34 17   7.3   4.0 | -22.7  -8.9  245  41 21   6.3   3.5
 26000 -20.6  -5.1  245  37 19   7.3   4.0 | -20.8  -5.4  250  42 22   6.3   3.5
 25000 -18.4  -1.1  250  40 21   7.2   4.0 | -18.9  -2.0  250  43 22   6.4   3.5
 24000 -16.5   2.3  250  39 20   6.5   3.6 | -17.1   1.2  255  41 21   6.3   3.5
 23000 -14.6   5.7  255  37 19   6.5   3.6 | -15.2   4.6  255  39 20   6.3   3.5
 22000 -12.7   9.1  260  35 18   6.7   3.7 | -13.3   8.1  255  37 19   6.6   3.6
 21000 -10.5  13.1  265  33 17   7.3   4.0 | -11.2  11.8  260  35 18   7.3   4.0
 20000  -8.4  16.9  265  30 16   7.3   4.0 |  -9.1  15.6  260  33 17   7.3   4.0
 19500  -7.4  18.7  265  29 15   7.3   4.0 |  -8.0  17.6  260  33 17   7.3   4.0
 19000  -6.3  20.7  265  28 15   7.2   3.9 |  -6.9  19.6  260  32 16   7.8   4.3
 18500  -5.3  22.5  265  28 14   7.1   3.9 |  -5.8  21.6  260  31 16   7.8   4.3
 18000  -4.2  24.4  265  28 14   6.8   3.7 |  -4.7  23.5  260  30 16   7.6   4.2
 17500  -3.3  26.1  265  28 14   5.8   3.2 |  -3.6  25.5  260  29 15   7.1   3.9
 17000  -2.5  27.5  260  28 14   5.8   3.2 |  -2.6  27.3  260  28 15   7.0   3.9
 16500  -1.7  28.9  260  27 14   6.0   3.3 |  -1.5  29.3  265  27 14   8.1   4.4
 16000  -0.8  30.6  260  27 14   6.0   3.3 |  -0.3  31.5  265  26 13   8.0   4.4
 15500   0.1  32.2  260  26 14   6.3   3.4 |   0.9  33.6  265  25 13   7.4   4.0
 15000   1.5  34.7  260  25 13   6.5   3.6 |   2.4  36.3  265  26 13   6.8   3.7
 14500   2.4  36.3  260  24 13   7.4   4.1 |   3.3  37.9  270  26 14   5.9   3.2
 14000   3.6  38.5  260  24 12   7.6   4.2 |   4.1  39.4  270  25 13   5.7   3.1
 13500   4.7  40.5  260  24 12   7.6   4.2 |   5.0  41.0  270  24 12   6.1   3.4
 13000   5.8  42.4  260  23 12   7.5   4.1 |   5.9  42.6  270  23 12   6.5   3.6
 12500   6.9  44.4  265  23 12   7.5   4.1 |   6.8  44.2  270  22 11   7.0   3.8
 12000   8.0  46.4  265  22 11   8.0   4.4 |   7.9  46.2  270  21 11   7.7   4.2
 11750   8.6  47.5  265  22 11   8.0   4.4 |   8.4  47.1  270  20 10   8.0   4.4
 11500   9.2  48.6  265  21 11   7.9   4.3 |   8.9  48.0  270  19 10   7.1   3.9
 11250   9.8  49.6  265  21 11   7.6   4.2 |   9.4  48.9  270  18  9   8.0   4.4
 11000  10.3  50.5  265  21 11   7.4   4.0 |  10.1  50.2  270  16  8   9.9   5.4
 10750  10.9  51.6  270  22 11   7.5   4.1 |  10.8  51.4  265  14  7   9.8   5.4
 10500  11.4  52.5  270  22 11   7.2   4.0 |  11.5  52.7  265  13  7   9.3   5.1
 10250  11.9  53.4  270  23 12   6.6   3.6 |  12.1  53.8  260  12  6   7.7   4.2
 10000  12.4  54.3  270  23 12   6.7   3.7 |  12.7  54.9  260  11  6   9.3   5.1
  9750  12.9  55.2  270  24 12   7.4   4.1 |  13.5  56.3  255  11  6  11.3   6.2
  9500  13.4  56.1  270  24 12   6.1   3.3 |  14.3  57.7  255  11  6  10.2   5.6
  9250  13.7  56.7  270  24 12   3.8   2.1 |  15.1  59.2  255  11  5   9.1   5.0
  9000  14.0  57.2  270  24 12   3.4   1.9 |  15.7  60.3  255  10  5   9.3   5.1
  8750  14.2  57.6  270  23 12   2.2   1.2 |  16.5  61.7  250  10  5  10.7   5.9
  8500  14.4  57.9  265  22 11   4.1   2.2 |  17.3  63.1  250  10  5  10.9   6.0
  8250  14.9  58.8  265  20 10   7.2   4.0 |  18.1  64.6  250   9  5  10.4   5.7
  8000  15.4  59.7  260  17  9   6.4   3.5 |  18.8  65.8  250   9  5  10.3   5.7
  7750  15.9  60.6  260  14  7   8.7   4.8 |  19.6  67.3  250   9  5  10.7   5.9
  7500  16.6  61.9  255  12  6   8.5   4.6 |  20.4  68.7  245   9  4  11.0   6.0
  7250  17.1  62.8  255  11  6   5.5   3.0 |  21.2  70.2  245   8  4  10.7   5.9
  7000  17.6  63.7  250  10  5   7.9   4.4 |  22.0  71.6  245   8  4  10.9   6.0
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           09/21/2016 at 1500 MDT          |       09/21/2016 at 1800 MDT
                                           |
K index... +30.8  LI... +271.0             | K index... +25.4  LI... +272.4
CAPE... +293.0  CIN... -1.1                | CAPE... +18.2  CIN... -51.4
                                           |
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 -66.4 -87.5  260  35 18   3.6   2.0 | -66.2 -87.2  260  34 18   3.5   1.9
 45000 -60.3 -76.5  265  48 25   4.5   2.5 | -60.2 -76.4  265  46 24   4.5   2.5
 40000 -53.2 -63.8  260  50 26   6.9   3.8 | -53.0 -63.4  265  43 22   6.6   3.6
 38000 -49.0 -56.2  255  49 25   6.9   3.8 | -49.0 -56.2  250  40 21   6.7   3.7
 36000 -44.9 -48.8  250  49 25   6.7   3.7 | -45.0 -49.0  240  39 20   6.4   3.5
 34000 -39.9 -39.8  245  47 24   8.5   4.7 | -39.6 -39.3  240  38 20   9.3   5.1
 32000 -34.8 -30.6  245  43 22   8.3   4.6 | -34.0 -29.2  240  37 19   9.1   5.0
 30000 -29.0 -20.2  245  41 21   8.7   4.8 | -28.4 -19.1  245  35 18   8.2   4.5
 29000 -26.4 -15.5  245  39 20   8.7   4.8 | -26.0 -14.8  250  34 18   8.2   4.5
 28000 -23.9 -11.0  245  38 20   7.3   4.0 | -23.6 -10.5  255  34 18   7.0   3.8
 27000 -21.8  -7.2  250  36 19   7.1   3.9 | -21.6  -6.9  260  34 17   6.8   3.7
 26000 -19.7  -3.5  250  34 18   7.1   3.9 | -19.6  -3.3  260  33 17   6.8   3.7
 25000 -17.6   0.3  255  32 17   7.0   3.9 | -17.6   0.3  265  33 17   6.8   3.7
 24000 -15.7   3.7  260  31 16   6.5   3.6 | -15.7   3.7  265  32 16   6.7   3.7
 23000 -13.8   7.2  260  30 15   6.5   3.6 | -13.7   7.3  270  30 16   6.7   3.7
 22000 -11.9  10.6  265  29 15   6.4   3.5 | -11.7  10.9  275  29 15   6.6   3.6
 21000 -10.2  13.6  265  28 14   5.8   3.2 |  -9.9  14.2  275  28 14   6.2   3.4
 20000  -8.5  16.7  265  27 14   5.8   3.2 |  -8.1  17.4  275  26 14   6.2   3.4
 19500  -7.7  18.1  265  26 14   5.8   3.2 |  -7.2  19.0  280  26 13   6.3   3.4
 19000  -6.9  19.6  270  26 13   5.5   3.0 |  -6.4  20.5  280  25 13   5.6   3.1
 18500  -6.1  21.0  270  26 13   5.5   3.0 |  -5.6  21.9  280  25 13   5.6   3.1
 18000  -5.3  22.5  270  26 13   5.7   3.1 |  -4.7  23.5  280  25 13   5.8   3.2
 17500  -4.4  24.1  270  26 13   6.1   3.4 |  -3.8  25.2  280  24 12   6.6   3.6
 17000  -3.5  25.7  270  26 13   6.1   3.3 |  -2.8  27.0  280  24 12   6.6   3.6
 16500  -2.7  27.1  270  25 13   6.3   3.5 |  -1.8  28.8  275  23 12   7.1   3.9
 16000  -1.8  28.8  270  24 12   6.4   3.5 |  -0.8  30.6  275  22 12   7.2   3.9
 15500  -0.9  30.4  265  22 11   7.0   3.9 |   0.3  32.5  270  22 11   7.7   4.2
 15000   0.8  33.4  260  19 10   7.7   4.2 |   2.1  35.8  265  19 10   8.3   4.6
 14500   1.9  35.4  255  17  9   8.7   4.8 |   3.3  37.9  260  17  9   7.6   4.2
 14000   3.2  37.8  250  16  8   8.9   4.9 |   4.4  39.9  255  16  8   7.3   4.0
 13500   4.5  40.1  245  15  8   9.4   5.1 |   5.4  41.7  245  15  8   7.5   4.1
 13000   5.9  42.6  245  14  7   9.7   5.3 |   6.5  43.7  240  14  7   7.7   4.2
 12500   7.4  45.3  240  14  7   8.9   4.9 |   7.7  45.9  235  13  7   7.3   4.0
 12000   8.7  47.7  235  14  7   9.8   5.3 |   8.7  47.7  230  15  8   7.1   3.9
 11750   9.4  48.9  230  14  7   9.6   5.3 |   9.2  48.6  230  16  8   6.9   3.8
 11500  10.1  50.2  230  14  7   9.3   5.1 |   9.7  49.5  230  18  9   7.2   4.0
 11250  10.8  51.4  220  14  7   9.3   5.1 |  10.3  50.5  230  19 10   7.2   4.0
 11000  11.5  52.7  220  14  7   9.6   5.3 |  10.7  51.3  230  20 10   6.9   3.8
 10750  12.2  54.0  215  14  7   9.6   5.3 |  11.2  52.2  230  21 11   6.9   3.8
 10500  12.9  55.2  215  14  7   9.3   5.1 |  11.7  53.1  230  22 11   6.9   3.8
 10250  13.6  56.5  210  14  7   8.5   4.6 |  12.2  54.0  230  22 11   6.3   3.5
 10000  14.2  57.6  205  15  8   9.6   5.3 |  12.6  54.7  230  22 11   8.1   4.5
  9750  15.0  59.0  205  15  8  10.9   6.0 |  13.3  55.9  225  22 11  10.0   5.5
  9500  15.8  60.4  205  15  8  10.2   5.6 |  14.0  57.2  225  21 11   9.2   5.0
  9250  16.6  61.9  200  15  8   9.2   5.1 |  14.6  58.3  220  21 11   7.9   4.3
  9000  17.2  63.0  200  15  8   9.3   5.1 |  15.2  59.4  220  20 10   7.8   4.3
  8750  18.0  64.4  200  15  8  10.7   5.9 |  15.8  60.4  220  20 10   9.9   5.4
  8500  18.8  65.8  200  15  8  10.8   5.9 |  16.6  61.9  215  20 10  10.0   5.5
  8250  19.6  67.3  200  15  8  10.1   5.5 |  17.3  63.1  215  19 10   8.8   4.8
  8000  20.3  68.5  195  15  8   9.8   5.4 |  17.9  64.2  210  18  9   8.4   4.6
  7750  21.1  70.0  195  15  8  10.6   5.8 |  18.5  65.3  210  17  9   9.1   5.0
  7500  21.8  71.2  195  14  7   9.5   5.2 |  19.1  66.4  205  16  8   6.1   3.3
  7250  22.4  72.3  195  14  7   7.4   4.1 |  19.3  66.7  200  14  7   2.2   1.2
  7000  23.0  73.4  195  13  7   8.9   4.9 |  19.5  67.1  200  12  6   4.2   2.3
  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) and again by approximately 1830 MST/1930 MDT (0130 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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