Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13
957
UXUS97 KPUB 061203
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0603 MDT Friday, May 6, 2016

This forecast is for Friday, May 6, 2016:

If the trigger temperature of 67.8 F/19.9 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1042 ft/min (5.3 m/s)
   Maximum height of thermals.................. 19019 ft MSL (12261 ft AGL)

Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 0900 MDT
Time of overdevelopment........................ 1500 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 9092 ft MSL (2335 ft AGL)
Thermal soaring outlook for Saturday 05/07..... Excellent

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

Remarks...

Sunrise/Sunset.................... 05:54:51 / 19:56:07 MDT
Total possible sunshine........... 14 hr 1 min 16 sec (841 min 16 sec)
Altitude of sun at 12:55:40 MDT... 67.86 degrees

Upper air data from numerical model forecast valid on 05/06/2016 at 0600 MDT

Freezing level.................. 14107 ft MSL (7349 ft AGL)
Convective condensation level... 17431 ft MSL (10673 ft AGL)
Lifted condensation level....... 17461 ft MSL (10704 ft AGL)
Lifted index.................... -0.1
K index......................... +20.4

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  -64.0 -83.2   245   33   17  -2.1  -1.1      M     M       M      M    M
 45000  -66.5 -87.7   225   40   21   2.8   1.5      M     M       M      M    M
 40000  -62.4 -80.3   235   25   13   2.4   1.3      M     M       M      M    M
 38000  -58.2 -72.8   225   25   13   8.0   4.4      M     M       M      M    M
 36000  -53.4 -64.1   215   28   14   8.0   4.4      M     M       M      M    M
 34000  -48.0 -54.4   210   29   15   7.8   4.3      M     M       M      M    M
 32000  -43.4 -46.1   215   27   14   7.8   4.3      M     M       M      M    M
 30000  -38.4 -37.1   220   24   13   8.6   4.7   30.7  87.2     6.5      M    M
 29000  -35.8 -32.4   225   23   12   8.6   4.7   30.3  86.5     6.3      M    M
 28000  -33.2 -27.8   225   22   11   8.6   4.7   29.9  85.9     6.1      M    M
 27000  -30.6 -23.1   225   21   11   8.8   4.8   29.5  85.2     5.8      M    M
 26000  -28.0 -18.4   225   19   10   8.8   4.8   29.1  84.4     5.6      M    M
 25000  -25.3 -13.5   225   18    9   8.8   4.8   28.8  83.9     5.4      M    M
 24000  -23.0  -9.4   220   16    8   6.6   3.6   28.2  82.8     4.9      M    M
 23000  -21.0  -5.8   215   15    8   6.7   3.7   27.0  80.7     4.0      M    M
 22000  -19.0  -2.2   210   14    7   6.7   3.7   26.0  78.8     3.1      M    M
 21000  -17.1   1.2   205   15    7   6.5   3.6   24.9  76.8     2.1      M    M
 20000  -15.2   4.6   200   17    9   6.6   3.6   23.7  74.7     1.1      M    M
 19500  -14.2   6.4   195   18    9   6.6   3.6   23.2  73.8     0.5      M    M
 19000  -13.3   8.1   195   19   10   6.9   3.8   22.7  72.9     0.1      M    M
 18500  -12.2  10.0   195   19   10   8.0   4.4   22.4  72.2    -0.3   1201  6.1
 18000  -11.0  12.2   195   18    9   8.0   4.4   22.1  71.7    -0.6   1151  5.8
 17500   -9.8  14.4   195   17    9   8.2   4.5   21.8  71.2    -0.9   1100  5.6
 17000   -8.6  16.5   200   15    8   8.3   4.5   21.5  70.7    -1.1   1048  5.3
 16500   -7.4  18.7   205   14    7   8.7   4.8   21.3  70.3    -1.3    996  5.1
 16000   -5.2  22.6   210   12    6   9.6   5.3   21.2  70.1    -1.4    910  4.6
 15500   -3.8  25.2   210   11    6   9.6   5.3   21.2  70.1    -1.4    852  4.3
 15000   -2.3  27.9   215   10    5   9.6   5.3   21.1  70.1    -1.4    793  4.0
 14500   -0.9  30.4   215   10    5   9.7   5.3   21.1  70.1    -1.5    735  3.7
 14000    0.6  33.1   220   10    5   9.7   5.3   21.1  70.0    -1.5    677  3.4
 13500    2.0  35.6   220   10    5   9.7   5.3   21.1  70.0    -1.5    618  3.1
 13000    3.5  38.3   225   10    5  10.1   5.5   21.2  70.1    -1.5    559  2.8
 12500    5.0  41.0   230   11    6   7.2   3.9   21.3  70.3    -1.4    499  2.5
 12000    6.1  43.0   235   12    6   9.6   5.3   20.8  69.5    -1.9    452  2.3
 11750    6.7  44.1   235   13    7   8.7   4.8   20.7  69.3    -1.9    425  2.2
 11500    7.4  45.3   240   14    7   9.0   4.9   20.7  69.2    -2.0    398  2.0
 11250    8.1  46.6   240   15    8   8.9   4.9   20.6  69.1    -2.1    371  1.9
 11000    8.7  47.7   240   16    8   8.9   4.9   20.6  69.0    -2.2    344  1.7
 10750    9.4  48.9   240   17    9   8.7   4.8   20.5  68.9    -2.3    317  1.6
 10500   10.0  50.0   240   17    9   9.2   5.0   20.4  68.7    -2.3    290  1.5
 10250   10.7  51.3   240   18    9   7.4   4.1   20.3  68.6    -2.4    262  1.3
 10000   11.2  52.2   240   18    9   7.5   4.1   20.1  68.2    -2.6    240  1.2
  9750   11.9  53.4   235   18    9   9.1   5.0   20.0  68.1    -2.7    213  1.1
  9500   12.5  54.5   235   18    9   9.1   5.0   20.0  67.9    -2.8    185  0.9
  9250   13.2  55.8   235   17    9   7.7   4.2   19.9  67.8    -2.9    158  0.8
  9000   13.7  56.7   235   17    9   6.3   3.5   19.7  67.4    -3.1    136  0.7
  8750   14.2  57.6   235   16    8   7.9   4.3   19.5  67.0    -3.3    113  0.6
  8500   14.8  58.6   235   16    8   8.6   4.7   19.3  66.8    -3.4     87  0.4
  8250   15.3  59.5   235   15    8   3.3   1.8   19.1  66.4    -3.7     64  0.3
  8000   15.2  59.4   235   14    7  -3.2  -1.8   18.3  65.0    -4.5     59  0.3
  7750   15.1  59.2   235   13    7   6.1   3.4   17.6  63.6    -5.3     55  0.3
  7500   15.8  60.4   230   13    6   3.2   1.8   17.5  63.5    -5.5     29  0.1
  7250   14.9  58.8   235   11    6 -23.6 -12.9   16.2  61.2    -6.8     46  0.2
  7000   12.4  54.3   240    8    4 -36.9 -20.2   13.5  56.4    -9.6    114  0.6
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           05/06/2016 at 0900 MDT          |       05/06/2016 at 1200 MDT
                                           |
K index... +22.9  LI... +272.8             | K index... +21.9  LI... +271.8
CAPE... +3.1  CIN... -26.0                 | CAPE... +135.3  CIN... -23.4
                                           |
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 -63.4 -82.1  245  33 17  -1.9  -1.0 | -62.2 -80.0  245  33 17  -1.0  -0.6
 45000 -65.8 -86.4  230  47 24   2.7   1.5 | -63.6 -82.5  235  51 26   0.7   0.4
 40000 -61.9 -79.4  240  41 21   2.0   1.1 | -62.7 -80.9  235  45 23  -0.3  -0.2
 38000 -57.8 -72.0  230  33 17   7.5   4.1 | -58.7 -73.7  225  39 20   7.7   4.2
 36000 -53.3 -63.9  205  27 14   7.5   4.1 | -54.1 -65.4  210  35 18   7.7   4.2
 34000 -48.8 -55.8  195  26 14   7.5   4.1 | -49.2 -56.6  200  34 17   8.4   4.6
 32000 -44.3 -47.7  205  26 14   7.5   4.1 | -44.2 -47.6  200  33 17   8.4   4.6
 30000 -39.4 -38.9  205  25 13   9.0   4.9 | -39.0 -38.2  205  32 16   9.1   5.0
 29000 -36.7 -34.1  205  24 13   9.0   4.9 | -36.3 -33.3  205  30 16   9.2   5.0
 28000 -34.0 -29.2  205  23 12   9.0   4.9 | -33.6 -28.5  210  29 15   9.1   5.0
 27000 -30.8 -23.4  205  21 11   8.5   4.7 | -30.4 -22.7  210  27 14   8.0   4.4
 26000 -28.2 -18.8  205  20 10   8.5   4.7 | -28.0 -18.4  210  26 13   8.0   4.4
 25000 -25.7 -14.3  205  18  9   8.5   4.7 | -25.7 -14.3  210  25 13   8.0   4.4
 24000 -23.3  -9.9  205  17  9   7.6   4.2 | -23.4 -10.1  205  23 12   7.2   4.0
 23000 -21.0  -5.8  205  17  9   7.6   4.2 | -21.3  -6.3  205  22 11   7.2   4.0
 22000 -18.7  -1.7  210  16  8   7.7   4.2 | -19.1  -2.4  200  21 11   7.2   4.0
 21000 -16.8   1.8  205  18  9   5.9   3.2 | -17.1   1.2  195  22 11   6.6   3.6
 20000 -15.1   4.8  200  20 11   6.0   3.3 | -15.1   4.8  195  24 12   6.6   3.6
 19500 -14.3   6.3  195  22 11   6.1   3.3 | -14.1   6.6  195  25 13   6.7   3.7
 19000 -13.4   7.9  195  24 12   6.5   3.6 | -13.1   8.4  195  26 13   7.0   3.8
 18500 -12.4   9.7  195  24 12   7.3   4.0 | -12.0  10.4  190  26 14   7.7   4.2
 18000 -11.3  11.7  195  25 13   7.2   4.0 | -10.9  12.4  190  27 14   7.6   4.2
 17500 -10.2  13.6  195  25 13   8.4   4.6 |  -9.8  14.4  190  28 14   8.1   4.5
 17000  -9.0  15.8  195  23 12   8.5   4.6 |  -8.6  16.5  190  28 15   8.2   4.5
 16500  -7.7  18.1  195  22 11   8.8   4.8 |  -7.4  18.7  190  29 15   8.3   4.5
 16000  -6.4  20.5  195  21 11   9.2   5.0 |  -6.2  20.8  190  28 15   8.3   4.6
 15500  -5.0  23.0  190  19 10   9.3   5.1 |  -5.0  23.0  190  28 14   8.4   4.6
 15000  -3.6  25.5  190  18  9   9.6   5.3 |  -3.8  25.2  190  27 14   8.4   4.6
 14500  -2.2  28.0  190  17  9   9.6   5.3 |  -2.6  27.3  190  26 13   8.3   4.6
 14000  -0.7  30.7  190  15  8   9.5   5.2 |  -0.6  30.9  190  24 12   8.8   4.8
 13500   1.4  34.5  195  14  7   9.7   5.3 |   0.7  33.3  190  23 12   8.9   4.9
 13000   2.9  37.2  195  13  7  10.3   5.6 |   2.1  35.8  195  22 11   9.8   5.4
 12500   4.5  40.1  195  12  6   8.5   4.7 |   3.5  38.3  195  20 11   8.6   4.7
 12000   5.7  42.3  200  12  6   9.6   5.3 |   4.8  40.6  200  20 10   9.3   5.1
 11750   6.4  43.5  205  12  6   9.1   5.0 |   5.4  41.7  200  19 10   9.1   5.0
 11500   7.0  44.6  205  13  7   9.3   5.1 |   6.1  43.0  200  19 10   8.9   4.9
 11250   7.7  45.9  210  13  7   8.9   4.9 |   6.7  44.1  205  18 10   8.1   4.5
 11000   8.4  47.1  210  13  7   8.9   4.9 |   7.4  45.3  205  18  9   9.1   5.0
 10750   9.0  48.2  215  14  7   8.9   4.9 |   8.1  46.6  210  18  9   9.9   5.4
 10500   9.7  49.5  220  14  7   9.4   5.1 |   8.8  47.8  210  17  9  10.1   5.5
 10250  10.3  50.5  220  15  8   7.2   3.9 |   9.5  49.1  215  17  9   8.2   4.5
 10000  10.8  51.4  225  16  8   7.6   4.2 |  10.0  50.0  215  16  8   8.7   4.8
  9750  11.5  52.7  225  16  8  10.0   5.5 |  10.8  51.4  215  16  8  10.9   6.0
  9500  12.2  54.0  225  17  9   9.4   5.2 |  11.6  52.9  215  15  8  10.4   5.7
  9250  12.9  55.2  225  17  9   8.6   4.7 |  12.3  54.1  215  15  8   9.8   5.4
  9000  13.5  56.3  225  17  9   7.5   4.1 |  13.0  55.4  215  15  8   9.3   5.1
  8750  14.1  57.4  230  17  9   7.4   4.1 |  13.7  56.7  215  14  7  10.2   5.6
  8500  14.6  58.3  230  16  8   6.9   3.8 |  14.5  58.1  215  14  7  10.6   5.8
  8250  15.1  59.2  230  16  8   5.5   3.0 |  15.3  59.5  215  14  7  10.5   5.8
  8000  15.4  59.7  230  14  7   4.2   2.3 |  16.1  61.0  215  14  7  11.0   6.1
  7750  15.7  60.3  230  12  6   6.2   3.4 |  16.9  62.4  215  14  7   9.5   5.2
  7500  16.1  61.0  230  10  5   6.2   3.4 |  17.5  63.5  210  13  7   9.5   5.2
  7250  16.4  61.5  225   8  4   3.1   1.7 |  18.3  64.9  210  13  7  12.6   6.9
  7000  16.4  61.5  225   7  4   3.0   1.7 |  19.2  66.6  210  12  6  12.9   7.1
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/06/2016 at 1500 MDT          |       05/06/2016 at 1800 MDT
                                           |
K index... +20.0  LI... +271.3             | K index... +23.6  LI... +271.0
CAPE... +570.9  CIN... -30.6               | CAPE... +511.7  CIN... -22.9
                                           |
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 -61.9 -79.4  250  37 19  -1.3  -0.7 | -61.7 -79.1  250  31 16  -0.9  -0.5
 45000 -63.6 -82.5  240  50 26   1.1   0.6 | -62.8 -81.0  240  41 21   1.5   0.8
 40000 -62.2 -80.0  240  49 25   0.3   0.2 | -60.8 -77.4  240  55 28   0.9   0.5
 38000 -58.7 -73.7  240  50 26   6.7   3.7 | -57.5 -71.5  235  55 28   6.2   3.4
 36000 -54.8 -66.6  235  51 26   6.7   3.7 | -53.8 -64.8  235  53 28   6.2   3.4
 34000 -50.0 -58.0  230  49 25   9.2   5.0 | -49.5 -57.1  230  52 27   8.3   4.6
 32000 -44.5 -48.1  225  44 23   9.2   5.0 | -44.5 -48.1  225  51 26   8.3   4.6
 30000 -38.9 -38.0  215  39 20   9.5   5.2 | -39.3 -38.7  220  51 26   9.0   5.0
 29000 -36.1 -33.0  210  36 19   9.5   5.2 | -36.6 -33.9  220  53 27   9.0   5.0
 28000 -33.3 -27.9  205  35 18   9.4   5.2 | -33.2 -27.8  220  55 28   9.1   5.0
 27000 -30.2 -22.4  205  35 18   7.2   3.9 | -30.5 -22.9  220  55 28   8.7   4.8
 26000 -28.0 -18.4  210  38 20   7.2   3.9 | -27.9 -18.2  215  54 28   8.7   4.8
 25000 -25.9 -14.6  215  41 21   7.2   4.0 | -25.3 -13.5  215  54 28   8.7   4.8
 24000 -23.6 -10.5  215  42 22   8.2   4.5 | -23.0  -9.4  215  52 27   6.4   3.5
 23000 -21.1  -6.0  215  40 21   8.3   4.5 | -21.1  -6.0  215  49 25   6.4   3.5
 22000 -18.7  -1.7  210  39 20   8.3   4.5 | -19.1  -2.4  210  45 23   6.5   3.6
 21000 -16.4   2.5  210  38 20   7.3   4.0 | -17.0   1.4  210  42 22   7.8   4.3
 20000 -14.2   6.4  210  39 20   7.3   4.0 | -14.7   5.5  210  40 20   7.9   4.3
 19500 -13.1   8.4  210  39 20   7.3   4.0 | -13.6   7.5  210  39 20   7.9   4.3
 19000 -12.0  10.4  210  39 20   7.2   4.0 | -12.4   9.7  210  38 19   8.0   4.4
 18500 -11.0  12.2  210  36 19   6.8   3.7 | -11.3  11.7  210  36 19   8.3   4.5
 18000 -10.1  13.8  210  32 17   6.8   3.7 | -10.1  13.8  210  35 18   8.3   4.6
 17500  -9.0  15.8  210  30 15   8.3   4.6 |  -8.9  16.0  210  33 17   8.5   4.7
 17000  -7.8  18.0  210  29 15   8.5   4.7 |  -7.6  18.3  205  31 16   8.6   4.7
 16500  -6.6  20.1  210  29 15   8.8   4.8 |  -6.4  20.5  205  29 15   8.6   4.7
 16000  -5.3  22.5  210  28 15   9.4   5.1 |  -5.1  22.8  205  27 14   8.5   4.6
 15500  -3.9  25.0  205  28 15   9.5   5.2 |  -3.9  25.0  200  25 13   8.5   4.7
 15000  -2.7  27.1  200  28 15   8.0   4.4 |  -2.7  27.1  195  24 12   8.5   4.7
 14500  -1.5  29.3  195  28 15   8.2   4.5 |  -1.5  29.3  190  23 12   8.5   4.7
 14000   0.2  32.4  190  28 15   8.1   4.4 |   0.3  32.5  180  24 12   7.7   4.2
 13500   1.4  34.5  190  28 14   8.1   4.4 |   1.4  34.5  175  25 13   7.7   4.2
 13000   2.6  36.7  185  27 14   7.7   4.2 |   2.6  36.7  175  26 13   8.4   4.6
 12500   3.7  38.7  185  27 14   7.9   4.3 |   3.8  38.8  175  27 14   7.6   4.2
 12000   4.9  40.8  180  26 13   7.9   4.3 |   4.9  40.8  170  28 14   9.0   4.9
 11750   5.5  41.9  180  25 13   8.0   4.4 |   5.6  42.1  170  28 14   9.0   5.0
 11500   6.1  43.0  180  25 13   7.8   4.3 |   6.2  43.2  170  28 14   8.8   4.8
 11250   6.7  44.1  180  24 13   8.8   4.8 |   6.9  44.4  170  28 14   9.7   5.3
 11000   7.4  45.3  175  24 12   9.6   5.2 |   7.7  45.9  170  28 15  10.0   5.5
 10750   8.0  46.4  175  23 12   8.9   4.9 |   8.4  47.1  170  28 14   9.3   5.1
 10500   8.7  47.7  175  22 11   9.7   5.3 |   9.1  48.4  170  28 14   9.8   5.4
 10250   9.3  48.7  170  21 11   7.4   4.0 |   9.8  49.6  170  27 14   8.5   4.6
 10000   9.8  49.6  170  21 11   8.2   4.5 |  10.4  50.7  170  27 14   8.9   4.9
  9750  10.5  50.9  170  20 10  11.1   6.1 |  11.1  52.0  170  27 14  10.4   5.7
  9500  11.3  52.3  170  20 10  10.5   5.8 |  11.9  53.4  170  26 14  10.1   5.5
  9250  12.1  53.8  170  20 10  10.0   5.5 |  12.6  54.7  170  26 13  10.0   5.5
  9000  12.8  55.0  170  20 10   9.5   5.2 |  13.3  55.9  170  26 13   9.7   5.3
  8750  13.5  56.3  170  19 10  10.6   5.8 |  14.0  57.2  175  25 13   9.8   5.4
  8500  14.3  57.7  170  19 10  11.1   6.1 |  14.8  58.6  175  25 13   9.9   5.4
  8250  15.1  59.2  170  19 10  10.5   5.8 |  15.5  59.9  175  25 13   9.8   5.4
  8000  15.9  60.6  170  19 10  10.7   5.9 |  16.2  61.2  175  24 12  10.0   5.5
  7750  16.7  62.1  170  19 10   9.3   5.1 |  17.0  62.6  175  23 12   9.4   5.1
  7500  17.3  63.1  170  18  9   8.6   4.7 |  17.6  63.7  175  22 11   8.8   4.8
  7250  18.0  64.4  170  17  9  12.1   6.6 |  18.2  64.8  175  20 10   7.1   3.9
  7000  19.0  66.2  170  17  9  14.7   8.0 |  18.6  65.5  175  19 10   3.9   2.1
  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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.