Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
000
UXUS97 KPUB 040953
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0353 MDT Monday, May 4, 2015

This forecast is for Monday, May 4, 2015:

If the trigger temperature of 52.6 F/11.5 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 11286 ft MSL (4528 ft AGL)

Forecast maximum temperature................... 54.0 F/12.7 C
Time of trigger temperature.................... 1130 MDT
Time of overdevelopment........................ None
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................. 9219 ft MSL (2461 ft AGL)
Thermal soaring outlook for Tuesday 05/05...... Poor

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

Remarks...

Sunrise/Sunset.................... 05:57:55 / 19:53:28 MDT
Total possible sunshine........... 13 hr 55 min 33 sec (835 min 33 sec)
Altitude of sun at 12:55:52 MDT... 67.08 degrees

Upper air data from numerical model forecast valid on 05/04/2015 at 0600 MDT

Freezing level.................. 11234 ft MSL (4476 ft AGL)
Convective condensation level... 9412 ft MSL (2654 ft AGL)
Lifted condensation level....... 10126 ft MSL (3368 ft AGL)
Lifted index.................... -0.7
K index......................... +24.9

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  -60.2 -76.4   280   39   20   2.0   1.1      M     M       M      M    M
 45000  -57.6 -71.7   270   40   21  -1.3  -0.7      M     M       M      M    M
 40000  -59.2 -74.6   245   33   17  -1.1  -0.6      M     M       M      M    M
 38000  -57.9 -72.2   230   29   15   3.7   2.1      M     M       M      M    M
 36000  -55.7 -68.3   215   26   13   3.7   2.0      M     M       M      M    M
 34000  -51.7 -61.1   200   24   12   9.2   5.0      M     M       M      M    M
 32000  -46.2 -51.2   205   22   11   9.1   5.0      M     M       M      M    M
 30000  -40.8 -41.4   210   20   10   9.0   4.9   28.7  83.6    12.7      M    M
 29000  -38.1 -36.6   215   19   10   9.0   4.9   28.3  83.0    12.6      M    M
 28000  -35.4 -31.7   220   19   10   9.0   4.9   28.1  82.6    12.5      M    M
 27000  -32.8 -27.0   220   19   10   8.3   4.6   27.8  82.0    12.4      M    M
 26000  -30.3 -22.5   220   17    9   8.3   4.6   27.2  80.9    12.0      M    M
 25000  -27.8 -18.0   220   16    8   8.4   4.6   26.7  80.0    11.8      M    M
 24000  -25.4 -13.7   220   15    8   7.6   4.2   26.2  79.1    11.5      M    M
 23000  -23.1  -9.6   215   13    7   7.6   4.2   25.3  77.6    10.9      M    M
 22000  -20.9  -5.6   210   12    6   7.7   4.2   24.6  76.3    10.4      M    M
 21000  -18.7  -1.7   200   10    5   6.9   3.8   23.8  74.9     9.8      M    M
 20000  -16.6   2.1   185    7    4   7.0   3.8   22.8  73.1     8.9      M    M
 19500  -15.6   3.9   175    6    3   7.0   3.8   22.4  72.2     8.6      M    M
 19000  -14.6   5.7   160    6    3   7.0   3.9   21.9  71.5     8.2      M    M
 18500  -13.6   7.5   150    5    3   6.8   3.7   21.5  70.7     7.8      M    M
 18000  -12.6   9.3   135    5    3   6.8   3.7   21.0  69.7     7.4      M    M
 17500  -11.5  11.3   125    6    3   6.9   3.8   20.5  68.9     7.0      M    M
 17000  -10.5  13.1   120    6    3   7.1   3.9   20.0  68.0     6.6      M    M
 16500   -9.5  14.9   120    6    3   7.1   3.9   19.6  67.2     6.2      M    M
 16000   -8.0  17.6   125    6    3   6.8   3.7   18.8  65.9     5.5      M    M
 15500   -7.0  19.4   130    6    3   6.7   3.7   18.4  65.0     5.1      M    M
 15000   -6.0  21.2   140    6    3   6.7   3.7   17.9  64.1     4.6      M    M
 14500   -5.1  22.8   140    6    3   6.8   3.7   17.4  63.2     4.1      M    M
 14000   -4.2  24.4   145    7    3   6.1   3.3   16.8  62.3     3.6      M    M
 13500   -3.3  26.1   150    7    4   6.2   3.4   16.2  61.2     3.0      M    M
 13000   -2.4  27.7   150    8    4   6.0   3.3   15.7  60.2     2.5      M    M
 12500   -1.6  29.1   155    8    4   6.1   3.4   15.1  59.1     1.8      M    M
 12000   -0.8  30.6   155    8    4   4.4   2.4   14.4  57.9     1.2      M    M
 11750   -0.5  31.1   155    7    4   3.8   2.1   13.9  57.1     0.7      M    M
 11500   -0.2  31.6   155    7    4   3.6   2.0   13.5  56.2     0.3      M    M
 11250    0.0  32.0   155    6    3   4.8   2.6   13.0  55.4    -0.2    358  1.8
 11000    0.5  32.9   160    7    4   6.1   3.3   12.7  54.9    -0.5    338  1.7
 10750    0.9  33.6   160    7    4   5.7   3.1   12.4  54.3    -0.8    318  1.6
 10500    1.3  34.3   160    8    4   6.1   3.3   12.1  53.8    -1.1    299  1.5
 10250    1.7  35.1   160    8    4   5.1   2.8   11.8  53.2    -1.4    279  1.4
 10000    2.0  35.6   155    8    4   4.2   2.3   11.4  52.5    -1.8    262  1.3
  9750    2.4  36.3   155    8    4   5.0   2.7   11.0  51.8    -2.3    244  1.2
  9500    2.7  36.9   155    9    4   5.0   2.8   10.6  51.1    -2.6    226  1.1
  9250    3.1  37.6   155    9    5   5.7   3.1   10.3  50.5    -3.0    208  1.1
  9000    3.5  38.3   150    9    5   6.5   3.6   10.0  50.0    -3.3    187  0.9
  8750    4.0  39.2   145    9    5   7.5   4.1    9.8  49.6    -3.5    165  0.8
  8500    4.6  40.3   145    9    5   8.5   4.6    9.7  49.4    -3.7    141  0.7
  8250    5.2  41.4   140    9    5   7.8   4.3    9.5  49.2    -3.9    116  0.6
  8000    5.7  42.3   145    8    4   7.3   4.0    9.4  48.9    -4.1     93  0.5
  7750    6.2  43.2   145    6    3   8.1   4.4    9.2  48.6    -4.3     69  0.4
  7500    6.8  44.2   145    4    2   6.9   3.8    9.1  48.3    -4.5     45  0.2
  7250    7.1  44.8   135    3    2   4.0   2.2    9.0  48.3    -4.6     27  0.1
  7000    7.4  45.3   130    3    1   3.6   2.0    9.0  48.3    -4.6     12  0.1
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           05/04/2015 at 0900 MDT          |       05/04/2015 at 1200 MDT
                                           |
K index... +25.3  LI... +272.5             | K index... +21.9  LI... +271.9
CAPE... +97.7  CIN... -14.6                | CAPE... +314.1  CIN... 0.0
                                           |
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 -59.7 -75.5  280  40 20   2.5   1.4 | -59.7 -75.5  275  38 20   3.1   1.7
 45000 -56.4 -69.5  265  43 22  -1.8  -1.0 | -55.5 -67.9  265  42 22  -2.4  -1.3
 40000 -58.5 -73.3  245  33 17  -1.2  -0.7 | -58.4 -73.1  245  31 16  -1.7  -0.9
 38000 -57.3 -71.1  230  25 13   3.3   1.8 | -57.2 -71.0  240  26 13   3.6   2.0
 36000 -55.3 -67.5  200  19 10   3.3   1.8 | -55.0 -67.0  225  21 11   3.6   2.0
 34000 -52.1 -61.8  180  18  9   8.8   4.8 | -51.7 -61.1  210  18  9   8.8   4.8
 32000 -46.9 -52.4  185  17  9   8.7   4.8 | -46.5 -51.7  200  18  9   8.8   4.8
 30000 -41.6 -42.9  190  16  8   9.1   5.0 | -41.1 -42.0  195  18  9   9.1   5.0
 29000 -38.9 -38.0  195  16  8   9.1   5.0 | -37.8 -36.0  195  18  9   9.1   5.0
 28000 -36.2 -33.2  200  16  8   9.1   5.0 | -35.0 -31.0  195  18  9   9.0   5.0
 27000 -32.9 -27.2  205  16  8   8.6   4.7 | -32.4 -26.3  195  17  9   8.5   4.6
 26000 -30.3 -22.5  205  16  8   8.6   4.7 | -29.9 -21.8  200  17  9   8.5   4.7
 25000 -27.7 -17.9  200  16  8   8.6   4.7 | -27.4 -17.3  200  17  9   8.5   4.7
 24000 -25.3 -13.5  200  15  8   7.7   4.2 | -25.0 -13.0  205  17  9   7.3   4.0
 23000 -22.9  -9.2  200  13  7   7.8   4.3 | -22.7  -8.9  205  17  9   7.5   4.1
 22000 -20.6  -5.1  200  12  6   7.8   4.3 | -20.5  -4.9  205  17  9   7.5   4.1
 21000 -18.4  -1.1  195  10  5   6.8   3.7 | -18.4  -1.1  205  17  9   7.1   3.9
 20000 -16.4   2.5  190   9  5   6.9   3.8 | -16.3   2.7  205  16  8   7.2   3.9
 19500 -15.4   4.3  185   8  4   6.9   3.8 | -15.2   4.6  210  15  8   7.2   3.9
 19000 -14.4   6.1  180   8  4   6.9   3.8 | -14.2   6.4  210  15  8   7.3   4.0
 18500 -13.4   7.9  175   7  4   6.7   3.7 | -13.2   8.2  210  14  7   6.4   3.5
 18000 -12.5   9.5  175   7  3   6.8   3.7 | -12.2  10.0  210  13  7   6.5   3.5
 17500 -11.5  11.3  170   6  3   7.0   3.9 | -11.3  11.7  215  13  7   6.5   3.6
 17000 -10.4  13.3  175   6  3   7.2   4.0 | -10.3  13.5  215  12  6   6.5   3.6
 16500  -9.4  15.1  180   5  3   7.2   4.0 |  -9.4  15.1  220  11  6   6.5   3.6
 16000  -8.4  16.9  185   5  3   7.0   3.8 |  -8.5  16.7  225  11  5   5.7   3.1
 15500  -7.4  18.7  195   5  3   7.0   3.9 |  -7.7  18.1  230  10  5   5.7   3.1
 15000  -6.4  20.5  205   5  2   6.5   3.6 |  -6.8  19.8  235  10  5   6.0   3.3
 14500  -5.5  22.1  215   5  2   6.5   3.5 |  -5.5  22.1  245   9  5   6.1   3.3
 14000  -4.1  24.6  225   4  2   5.8   3.2 |  -4.6  23.7  245   9  5   6.3   3.5
 13500  -3.3  26.1  235   4  2   5.8   3.2 |  -3.6  25.5  250   9  5   6.3   3.4
 13000  -2.4  27.7  245   5  2   6.2   3.4 |  -2.7  27.1  250   9  5   6.3   3.5
 12500  -1.5  29.3  255   5  3   6.0   3.3 |  -1.8  28.8  245   9  5   6.1   3.4
 12000  -0.8  30.6  255   5  3   5.6   3.1 |  -1.0  30.2  240   9  5   5.3   2.9
 11750  -0.3  31.5  250   5  3   6.0   3.3 |  -0.6  30.9  235   8  4   5.7   3.1
 11500   0.1  32.2  245   5  2   6.4   3.5 |  -0.2  31.6  230   8  4   5.8   3.2
 11250   0.5  32.9  245   4  2   4.4   2.4 |   0.2  32.4  225   7  4   5.1   2.8
 11000   0.8  33.4  240   4  2   3.5   1.9 |   0.6  33.1  220   7  3   5.0   2.8
 10750   1.1  34.0  230   3  2   4.9   2.7 |   0.9  33.6  210   6  3   5.7   3.1
 10500   1.4  34.5  220   3  1   4.5   2.5 |   1.3  34.3  200   5  3   5.6   3.1
 10250   1.7  35.1  205   2  1   4.7   2.6 |   1.7  35.1  185   5  3   5.5   3.0
 10000   2.1  35.8  190   2  1   4.7   2.6 |   2.1  35.8  170   5  2   7.1   3.9
  9750   2.4  36.3  180   2  1   4.6   2.5 |   2.7  36.9  160   5  2   9.2   5.0
  9500   2.7  36.9  160   2  1   4.5   2.5 |   3.3  37.9  150   5  2   9.4   5.1
  9250   3.0  37.4  145   2  1   4.9   2.7 |   3.9  39.0  135   5  3   9.7   5.3
  9000   3.4  38.1  130   2  1   5.2   2.9 |   4.6  40.3  135   5  3  10.0   5.5
  8750   3.8  38.8  115   3  1   7.7   4.2 |   5.4  41.7  130   5  3  11.3   6.2
  8500   4.5  40.1  100   3  2   9.8   5.4 |   6.2  43.2  125   5  3  12.2   6.7
  8250   5.1  41.2  090   4  2   8.8   4.8 |   7.1  44.8  120   5  2  11.1   6.1
  8000   5.7  42.3  090   4  2   8.9   4.9 |   7.9  46.2  120   5  2  11.0   6.0
  7750   6.4  43.5  090   4  2   8.2   4.5 |   8.7  47.7  120   5  2   9.9   5.4
  7500   6.9  44.4  085   3  2   7.6   4.2 |   9.4  48.9  120   5  2  10.7   5.9
  7250   7.4  45.3  085   3  2   8.1   4.5 |  10.3  50.5  115   5  2  13.8   7.6
  7000   8.0  46.4  090   3  2   8.0   4.4 |  11.3  52.3  115   5  2  13.5   7.4
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/04/2015 at 1500 MDT          |       05/04/2015 at 1800 MDT
                                           |
K index... +16.5  LI... +272.0             | K index... +16.2  LI... +272.2
CAPE... +277.9  CIN... M                   | CAPE... +201.8  CIN... M
                                           |
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 -59.3 -74.7  270  37 19   3.1   1.7 | -59.8 -75.6  270  36 18   3.3   1.8
 45000 -55.2 -67.4  260  42 22  -1.8  -1.0 | -55.5 -67.9  260  37 19  -2.3  -1.2
 40000 -58.1 -72.6  240  28 15  -1.8  -1.0 | -59.2 -74.6  230  29 15  -2.2  -1.2
 38000 -56.5 -69.7  235  25 13   4.2   2.3 | -57.1 -70.8  225  30 15   5.4   3.0
 36000 -54.0 -65.2  225  23 12   4.2   2.3 | -53.9 -65.0  225  32 16   5.4   3.0
 34000 -50.7 -59.3  220  20 10   7.9   4.3 | -49.9 -57.8  225  34 18   8.6   4.7
 32000 -46.0 -50.8  210  17  9   7.8   4.3 | -44.7 -48.5  225  38 19   8.6   4.7
 30000 -40.2 -40.4  205  16  8   9.4   5.2 | -38.8 -37.8  225  36 19   8.9   4.9
 29000 -37.4 -35.3  205  17  9   9.4   5.2 | -36.2 -33.2  225  33 17   8.9   4.9
 28000 -34.6 -30.3  205  18  9   9.4   5.1 | -33.5 -28.3  225  30 15   8.8   4.9
 27000 -32.0 -25.6  205  19 10   8.1   4.4 | -31.0 -23.8  225  28 14   7.9   4.3
 26000 -29.6 -21.3  205  21 11   8.1   4.4 | -28.7 -19.7  225  26 14   7.9   4.3
 25000 -27.1 -16.8  205  23 12   8.1   4.4 | -26.3 -15.3  220  25 13   7.9   4.3
 24000 -24.7 -12.5  205  24 13   7.8   4.3 | -24.0 -11.2  220  24 12   7.4   4.1
 23000 -22.4  -8.3  210  24 12   7.8   4.3 | -21.8  -7.2  225  22 11   7.5   4.1
 22000 -20.1  -4.2  215  23 12   7.8   4.3 | -19.5  -3.1  225  21 11   7.5   4.1
 21000 -17.8  -0.0  220  23 12   7.2   3.9 | -17.3   0.9  230  20 10   7.1   3.9
 20000 -15.7   3.7  225  23 12   7.2   4.0 | -15.2   4.6  235  19 10   7.1   3.9
 19500 -14.6   5.7  225  23 12   7.2   4.0 | -14.2   6.4  240  19 10   7.1   3.9
 19000 -13.5   7.7  230  23 12   7.3   4.0 | -13.1   8.4  245  19 10   7.1   3.9
 18500 -12.5   9.5  235  23 12   6.2   3.4 | -12.1  10.2  245  19 10   6.5   3.6
 18000 -11.6  11.1  235  23 12   6.3   3.5 | -11.1  12.0  245  19 10   6.6   3.6
 17500 -10.7  12.7  235  23 12   6.5   3.6 | -10.2  13.6  245  19 10   6.6   3.6
 17000  -9.7  14.5  240  23 12   6.6   3.6 |  -9.2  15.4  245  19 10   6.7   3.7
 16500  -8.7  16.3  240  23 12   6.7   3.7 |  -8.2  17.2  245  19 10   6.7   3.7
 16000  -7.7  18.1  240  23 12   7.1   3.9 |  -7.2  19.0  240  18  9   6.6   3.6
 15500  -6.7  19.9  240  22 12   7.1   3.9 |  -6.3  20.7  235  18  9   6.7   3.7
 15000  -5.2  22.6  240  21 11   7.0   3.8 |  -5.0  23.0  230  16  8   5.6   3.1
 14500  -4.2  24.4  235  20 10   7.0   3.9 |  -4.2  24.4  220  14  7   5.8   3.2
 14000  -3.2  26.2  235  18  9   6.5   3.6 |  -3.5  25.7  210  14  7   4.4   2.4
 13500  -2.3  27.9  235  16  8   6.6   3.6 |  -2.8  27.0  195  14  7   4.5   2.5
 13000  -1.3  29.7  230  14  7   6.4   3.5 |  -2.1  28.2  185  15  8   5.7   3.1
 12500  -0.4  31.3  225  11  6   5.9   3.3 |  -1.3  29.7  180  15  8   5.2   2.8
 12000   0.2  32.4  215   8  4   4.0   2.2 |  -0.7  30.7  175  16  8   5.8   3.2
 11750   0.5  32.9  205   8  4   4.8   2.6 |  -0.2  31.6  170  15  8   7.3   4.0
 11500   0.8  33.4  190   7  4   4.4   2.4 |   0.3  32.5  170  15  8   6.4   3.5
 11250   1.1  34.0  180   7  4   5.6   3.1 |   0.7  33.3  165  15  7   8.7   4.8
 11000   1.6  34.9  175   7  4   7.5   4.1 |   1.5  34.7  165  15  8   9.6   5.3
 10750   2.1  35.8  165   8  4   7.6   4.2 |   2.0  35.6  165  14  7   8.0   4.4
 10500   2.6  36.7  160   8  4   8.0   4.4 |   2.6  36.7  160  14  7   8.7   4.8
 10250   3.1  37.6  150   8  4   6.7   3.7 |   3.2  37.8  160  14  7   7.9   4.3
 10000   3.6  38.5  150   8  4   7.6   4.2 |   3.8  38.8  160  14  7   8.6   4.7
  9750   4.2  39.6  150   8  4  10.4   5.7 |   4.5  40.1  160  14  7  10.2   5.6
  9500   5.0  41.0  150   8  4  10.6   5.8 |   5.2  41.4  160  14  7  10.4   5.7
  9250   5.8  42.4  150   8  4  10.1   5.5 |   6.0  42.8  160  13  7   9.9   5.4
  9000   6.5  43.7  150   8  4   9.5   5.2 |   6.7  44.1  160  13  7   9.4   5.1
  8750   7.2  45.0  150   9  4  10.1   5.5 |   7.4  45.3  160  13  7  10.1   5.6
  8500   8.0  46.4  150   9  4  10.4   5.7 |   8.2  46.8  160  13  7  10.7   5.9
  8250   8.8  47.8  150   8  4  10.5   5.8 |   8.9  48.0  160  13  7  10.2   5.6
  8000   9.6  49.3  150   8  4  11.1   6.1 |   9.7  49.5  160  13  7  10.3   5.6
  7750  10.4  50.7  150   8  4   9.6   5.3 |  10.5  50.9  160  13  6   9.4   5.2
  7500  11.0  51.8  150   8  4   9.6   5.2 |  11.1  52.0  160  12  6   8.5   4.7
  7250  11.8  53.2  150   8  4  12.7   7.0 |  11.7  53.1  160  12  6   9.3   5.1
  7000  12.8  55.0  145   8  4  13.8   7.6 |  12.4  54.3  155  11  6   9.5   5.2
  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.