Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7

000
UXUS97 KPUB 181022
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0422 MDT Friday, April 18, 2014

This forecast is for Friday, April 18, 2014:

If the trigger temperature of 59.6 F/15.4 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 815 ft/min (4.1 m/s)
   Maximum height of thermals.................. 17647 ft MSL (10889 ft AGL)

Forecast maximum temperature................... 68.0 F/20.5 C
Time of trigger temperature.................... 1045 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 13748 ft MSL (6990 ft AGL)
Thermal soaring outlook for Saturday 04/19..... Good

Wave Soaring Index............................. Fair
Wave Soaring Index trend (to 1800 MDT)......... Neutral
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 14403 ft MSL (7645 ft AGL)
Wave soaring outlook for Saturday 04/19........ Good

Remarks...

Sunrise/Sunset.................... 06:18:11 / 19:38:11 MDT
Total possible sunshine........... 13 hr 20 min 0 sec (800 min 0 sec)
Altitude of sun at 12:58:20 MDT... 62.05 degrees

Upper air data from numerical model forecast valid on 04/18/2014 at 0600 MDT

Freezing level.................. 12611 ft MSL (5853 ft AGL)
Convective condensation level... 18350 ft MSL (11592 ft AGL)
Lifted condensation level....... 17853 ft MSL (11095 ft AGL)
Lifted index.................... +0.7
K index......................... +7.8

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  -60.3 -76.5   275   22   11   1.0   0.5      M     M       M      M    M
 45000  -59.0 -74.2   275   29   15  -2.9  -1.6      M     M       M      M    M
 40000  -64.2 -83.6   290   33   17  -3.4  -1.9      M     M       M      M    M
 38000  -61.7 -79.1   290   34   17   8.0   4.4      M     M       M      M    M
 36000  -57.0 -70.6   290   34   17   8.0   4.4      M     M       M      M    M
 34000  -51.4 -60.5   290   31   16   8.4   4.6      M     M       M      M    M
 32000  -46.4 -51.5   295   26   13   8.4   4.6      M     M       M      M    M
 30000  -41.2 -42.2   300   23   12   9.0   4.9   28.0  82.4     6.2      M    M
 29000  -38.5 -37.3   300   22   12   9.0   4.9   27.7  81.8     6.0      M    M
 28000  -35.8 -32.4   305   22   11   9.0   4.9   27.5  81.5     5.9      M    M
 27000  -33.1 -27.6   305   22   11   8.5   4.7   27.2  80.9     5.7      M    M
 26000  -30.5 -22.9   305   21   11   8.5   4.7   26.6  79.9     5.4      M    M
 25000  -28.0 -18.4   305   21   11   8.6   4.7   26.2  79.2     5.1      M    M
 24000  -25.5 -13.9   310   21   11   7.4   4.1   25.7  78.3     4.7      M    M
 23000  -23.2  -9.8   310   19   10   7.6   4.1   24.9  76.8     4.1      M    M
 22000  -21.0  -5.8   310   18    9   7.5   4.1   24.1  75.4     3.5      M    M
 21000  -18.8  -1.8   310   16    8   6.9   3.8   23.3  73.9     2.8      M    M
 20000  -16.7   1.9   305   15    8   6.9   3.8   22.2  72.0     1.9      M    M
 19500  -15.7   3.7   305   14    7   6.9   3.8   21.8  71.2     1.5      M    M
 19000  -14.7   5.5   305   13    7   6.9   3.8   21.3  70.4     1.1      M    M
 18500  -13.6   7.5   305   12    6   7.4   4.1   20.9  69.6     0.7      M    M
 18000  -12.5   9.5   305   12    6   7.4   4.1   20.5  68.9     0.3      M    M
 17500  -11.4  11.5   305   11    6   7.9   4.4   20.1  68.3    -0.0   1011  5.1
 17000  -10.2  13.6   300   11    5   8.2   4.5   19.9  67.8    -0.3    960  4.9
 16500   -9.0  15.8   295   10    5   8.1   4.5   19.6  67.3    -0.5    909  4.6
 16000   -7.3  18.9   290    8    4   7.3   4.0   19.1  66.3    -1.1    836  4.2
 15500   -6.2  20.8   280    7    3   7.0   3.8   18.7  65.6    -1.4    789  4.0
 15000   -5.2  22.6   300    6    3   6.5   3.6   18.2  64.7    -2.0    745  3.8
 14500   -4.3  24.3   315    7    4   6.6   3.6   17.6  63.7    -2.5    701  3.6
 14000   -3.2  26.2   325    8    4   7.6   4.2   17.2  63.0    -2.9    654  3.3
 13500   -2.1  28.2   330   10    5   7.5   4.1   16.9  62.4    -3.2    606  3.1
 13000   -0.9  30.4   330   11    6   9.2   5.1   16.7  62.0    -3.5    554  2.8
 12500    0.5  32.9   330   13    7   8.3   4.6   16.6  61.8    -3.6    499  2.5
 12000    1.7  35.1   325   15    8   8.8   4.8   16.3  61.3    -3.9    448  2.3
 11750    2.3  36.1   325   16    8   8.7   4.8   16.2  61.2    -4.0    421  2.1
 11500    3.0  37.4   320   17    9   9.0   4.9   16.1  61.0    -4.1    394  2.0
 11250    3.6  38.5   320   18    9   8.1   4.4   16.1  60.9    -4.2    367  1.9
 11000    4.2  39.6   315   18    9   7.8   4.3   15.9  60.6    -4.4    343  1.7
 10750    4.8  40.6   310   19   10   8.5   4.6   15.8  60.4    -4.5    317  1.6
 10500    5.4  41.7   310   19   10   8.5   4.7   15.7  60.2    -4.6    291  1.5
 10250    6.0  42.8   305   20   10   7.6   4.2   15.6  60.0    -4.7    265  1.3
 10000    6.6  43.9   305   19   10   7.7   4.2   15.4  59.7    -5.0    242  1.2
  9750    7.2  45.0   305   17    9   9.1   5.0   15.3  59.5    -5.1    215  1.1
  9500    7.9  46.2   305   16    8   9.1   5.0   15.2  59.4    -5.1    187  1.0
  9250    8.6  47.5   305   14    7   8.7   4.8   15.2  59.3    -5.2    160  0.8
  9000    9.2  48.6   305   14    7   8.3   4.5   15.1  59.1    -5.3    133  0.7
  8750    9.8  49.6   300   14    7   9.0   4.9   15.0  59.0    -5.4    107  0.5
  8500   10.5  50.9   300   15    8   7.7   4.2   14.9  58.8    -5.5     80  0.4
  8250   10.9  51.6   295   15    8   2.1   1.2   14.5  58.2    -5.9     61  0.3
  8000   10.7  51.3   290   15    8  -5.6  -3.1   13.7  56.6    -6.8     58  0.3
  7750   10.6  51.1   285   16    8  10.6   5.8   12.8  55.1    -7.6     54  0.3
  7500   11.5  52.7   280   15    8  -5.6  -3.1   13.0  55.4    -7.5     21  0.1
  7250    9.0  48.2   275   14    7 -51.2 -28.1   10.1  50.2   -10.5     89  0.5
  7000    5.0  41.0   280   11    6 -45.0 -24.7    5.9  42.6   -14.7    201  1.0
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           04/18/2014 at 0900 MDT          |       04/18/2014 at 1200 MDT
                                           |
K index... +4.4  LI... +3.0                | K index... +7.2  LI... +0.9
CAPE... 0.0  CIN... M                      | CAPE... 0.0  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 -61.6 -78.9  270  23 12   0.8   0.4 | -62.7 -80.9  270  26 14   0.2   0.1
 45000 -60.6 -77.1  275  30 16  -2.1  -1.1 | -62.5 -80.5  270  32 17  -0.6  -0.3
 40000 -63.9 -83.0  275  32 16  -2.1  -1.1 | -63.5 -82.3  250  34 18  -0.8  -0.4
 38000 -61.1 -78.0  275  33 17   7.9   4.3 | -59.7 -75.5  250  33 17   8.2   4.5
 36000 -56.3 -69.3  270  34 18   7.9   4.3 | -54.8 -66.6  255  32 16   8.2   4.5
 34000 -50.9 -59.6  265  33 17   8.0   4.4 | -50.1 -58.2  260  31 16   7.4   4.1
 32000 -46.1 -51.0  265  28 14   8.0   4.4 | -45.6 -50.1  250  30 15   7.4   4.1
 30000 -41.0 -41.8  265  24 13   8.9   4.9 | -40.9 -41.6  245  27 14   8.5   4.6
 29000 -38.3 -36.9  265  24 12   8.9   4.9 | -38.4 -37.1  240  25 13   8.5   4.6
 28000 -35.7 -32.3  270  23 12   8.9   4.9 | -35.2 -31.4  235  22 12   8.5   4.6
 27000 -33.0 -27.4  270  22 11   8.7   4.8 | -32.7 -26.9  235  21 11   8.5   4.6
 26000 -30.4 -22.7  265  20 10   8.7   4.8 | -30.1 -22.2  235  20 10   8.5   4.6
 25000 -27.8 -18.0  265  18  9   8.7   4.8 | -27.6 -17.7  235  19 10   8.5   4.6
 24000 -25.2 -13.4  265  16  8   8.1   4.5 | -25.1 -13.2  240  18  9   8.1   4.5
 23000 -22.8  -9.0  270  15  8   8.2   4.5 | -22.7  -8.9  240  16  8   8.2   4.5
 22000 -20.3  -4.5  270  13  7   8.1   4.5 | -20.2  -4.4  240  15  8   8.1   4.5
 21000 -18.0  -0.4  270  12  6   6.7   3.7 | -18.0  -0.4  245  16  8   6.9   3.8
 20000 -16.0   3.2  270  11  6   6.7   3.7 | -15.9   3.4  245  17  9   6.9   3.8
 19500 -15.0   5.0  265  11  6   6.7   3.7 | -14.9   5.2  245  18  9   6.9   3.8
 19000 -14.0   6.8  265  11  5   6.7   3.7 | -13.9   7.0  245  19 10   6.9   3.8
 18500 -13.0   8.6  265  11  5   7.2   4.0 | -12.9   8.8  245  20 10   6.9   3.8
 18000 -11.9  10.6  260  11  6   7.2   4.0 | -11.9  10.6  245  21 11   6.9   3.8
 17500 -10.9  12.4  260  11  6   7.6   4.1 | -10.8  12.6  245  21 11   7.4   4.1
 17000  -9.7  14.5  255  11  6   7.7   4.2 |  -9.7  14.5  245  21 11   7.5   4.1
 16500  -8.0  17.6  250  11  6   7.9   4.3 |  -8.6  16.5  245  20 10   7.5   4.1
 16000  -6.9  19.6  250  10  5   7.8   4.3 |  -7.5  18.5  245  19 10   7.5   4.1
 15500  -5.7  21.7  250  10  5   6.7   3.7 |  -6.4  20.5  250  18  9   7.5   4.1
 15000  -4.9  23.2  245   8  4   5.3   2.9 |  -5.3  22.5  250  17  9   7.6   4.2
 14500  -4.1  24.6  235   6  3   5.6   3.1 |  -4.2  24.4  245  15  8   7.6   4.2
 14000  -3.1  26.4  240   5  3   8.1   4.4 |  -2.6  27.3  250  13  7   7.4   4.1
 13500  -1.9  28.6  255   4  2   7.9   4.3 |  -1.5  29.3  250  11  6   7.6   4.1
 13000  -0.6  30.9  275   4  2   9.1   5.0 |  -0.2  31.6  250  10  5   9.1   5.0
 12500   0.7  33.3  300   5  2   8.0   4.4 |   1.1  34.0  255   9  4   8.1   4.4
 12000   1.9  35.4  315   6  3   9.3   5.1 |   2.3  36.1  255   8  4   9.6   5.3
 11750   2.6  36.7  320   7  3   9.1   5.0 |   3.0  37.4  250   8  4   9.3   5.1
 11500   3.3  37.9  320   8  4   9.2   5.0 |   3.6  38.5  250   8  4   9.4   5.2
 11250   4.0  39.2  320   8  4   8.9   4.9 |   4.3  39.7  250   8  4   8.6   4.7
 11000   4.6  40.3  320   9  5   8.6   4.7 |   4.9  40.8  250   8  4   9.0   4.9
 10750   5.2  41.4  320  10  5   8.5   4.7 |   5.6  42.1  245   8  4   9.7   5.3
 10500   5.9  42.6  315  11  6   8.9   4.9 |   6.3  43.3  240   8  4   9.8   5.4
 10250   6.5  43.7  315  12  6   7.3   4.0 |   7.0  44.6  235   7  4   8.2   4.5
 10000   7.0  44.6  310  12  6   7.5   4.1 |   7.6  45.7  230   8  4   8.7   4.8
  9750   7.6  45.7  310  11  6   9.6   5.3 |   8.3  46.9  230   8  4  10.7   5.9
  9500   8.3  46.9  310  10  5   9.5   5.2 |   9.1  48.4  225   7  4  10.3   5.6
  9250   9.0  48.2  305  10  5   8.9   4.9 |   9.8  49.6  220   7  4   9.2   5.0
  9000   9.7  49.5  305  10  5   8.4   4.6 |  10.5  50.9  220   8  4   8.6   4.7
  8750  10.3  50.5  300  10  5   9.0   4.9 |  11.2  52.2  215   8  4  10.5   5.8
  8500  11.0  51.8  300  11  6   8.5   4.7 |  12.0  53.6  215   8  4  11.2   6.1
  8250  11.5  52.7  295  12  6   5.8   3.2 |  12.8  55.0  210   8  4  10.3   5.7
  8000  11.8  53.2  290  12  6   4.1   2.2 |  13.5  56.3  210   8  4  10.5   5.7
  7750  12.1  53.8  285  12  6   5.5   3.0 |  14.3  57.7  205   8  4   9.4   5.1
  7500  12.5  54.5  280  11  6   3.7   2.0 |  15.0  59.0  205   8  4  10.2   5.6
  7250  12.5  54.5  275   9  5  -0.0  -0.0 |  15.8  60.4  205   8  4  12.9   7.1
  7000  12.4  54.3  270   7  4   0.8   0.4 |  16.7  62.1  205   7  4  12.0   6.6
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/18/2014 at 1500 MDT          |       04/18/2014 at 1800 MDT
                                           |
K index... +20.9  LI... -1.5               | K index... +24.3  LI... -1.4
CAPE... +79.5  CIN... -9.8                 | CAPE... +88.6  CIN... -11.0
                                           |
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 -62.8 -81.0  265  29 15  -0.3  -0.1 | -63.0 -81.4  265  32 16  -0.0  -0.0
 45000 -63.2 -81.8  270  38 19  -0.4  -0.2 | -63.0 -81.4  270  40 20  -0.1  -0.0
 40000 -63.9 -83.0  265  56 29  -0.7  -0.4 | -63.2 -81.8  255  55 28  -0.4  -0.2
 38000 -59.6 -75.3  265  50 26   8.9   4.9 | -58.8 -73.8  255  52 27   9.1   5.0
 36000 -54.3 -65.7  255  41 21   8.9   4.9 | -53.4 -64.1  250  47 24   9.1   5.0
 34000 -49.3 -56.7  250  35 18   7.6   4.2 | -48.5 -55.3  245  42 22   7.0   3.8
 32000 -44.7 -48.5  240  35 18   7.6   4.2 | -44.3 -47.7  240  40 20   7.0   3.8
 30000 -40.1 -40.2  235  33 17   8.0   4.4 | -39.9 -39.8  230  37 19   8.0   4.4
 29000 -37.7 -35.9  225  31 16   8.0   4.4 | -37.5 -35.5  230  36 18   8.0   4.4
 28000 -34.7 -30.5  215  29 15   8.0   4.4 | -34.5 -30.1  230  34 18   8.0   4.4
 27000 -32.3 -26.1  210  28 14   8.1   4.4 | -32.2 -26.0  225  33 17   7.7   4.2
 26000 -29.8 -21.6  210  26 14   8.1   4.4 | -29.9 -21.8  225  31 16   7.7   4.2
 25000 -27.4 -17.3  210  25 13   8.1   4.4 | -27.6 -17.7  220  30 16   7.7   4.2
 24000 -25.1 -13.2  210  23 12   7.1   3.9 | -25.4 -13.7  220  29 15   6.9   3.8
 23000 -23.0  -9.4  220  21 11   7.2   3.9 | -23.3  -9.9  225  28 14   6.9   3.8
 22000 -20.8  -5.4  225  19 10   7.2   3.9 | -21.2  -6.2  235  27 14   6.9   3.8
 21000 -18.8  -1.8  235  19 10   6.3   3.5 | -19.1  -2.4  240  26 13   7.0   3.9
 20000 -17.0   1.4  245  21 11   6.4   3.5 | -17.1   1.2  240  24 12   7.1   3.9
 19500 -16.0   3.2  250  22 11   6.4   3.5 | -16.0   3.2  245  23 12   7.2   3.9
 19000 -15.1   4.8  250  23 12   6.7   3.7 | -15.0   5.0  245  22 11   7.2   4.0
 18500 -14.0   6.8  255  24 12   7.9   4.3 | -13.9   7.0  250  20 10   7.6   4.1
 18000 -12.9   8.8  260  24 12   7.9   4.3 | -12.9   8.8  255  17  9   7.6   4.2
 17500 -11.7  10.9  260  24 12   8.2   4.5 | -11.7  10.9  260  14  7   8.8   4.8
 17000 -10.5  13.1  265  23 12   8.3   4.6 | -10.4  13.3  260  13  7   9.0   4.9
 16500  -9.3  15.3  265  21 11   8.6   4.7 |  -9.1  15.6  265  12  6   9.1   5.0
 16000  -8.1  17.4  265  19 10   9.0   4.9 |  -7.8  18.0  265  12  6   9.2   5.1
 15500  -6.8  19.8  265  18  9   9.0   4.9 |  -6.4  20.5  265  12  6   9.2   5.1
 15000  -5.4  22.3  265  16  8   9.2   5.0 |  -5.0  23.0  265  12  6   9.7   5.3
 14500  -4.1  24.6  260  15  8   9.2   5.0 |  -3.6  25.5  265  11  6   9.6   5.3
 14000  -2.1  28.2  255  14  7   9.3   5.1 |  -1.4  29.5  260  11  6   9.7   5.3
 13500  -0.7  30.7  255  14  7   9.4   5.1 |   0.0  32.0  260  11  5   9.7   5.3
 13000   0.8  33.4  250  13  7  10.0   5.5 |   1.5  34.7  255  10  5   9.8   5.4
 12500   2.3  36.1  250  13  7   8.6   4.7 |   3.0  37.4  250  10  5   8.5   4.6
 12000   3.5  38.3  240  12  6   9.8   5.4 |   4.2  39.6  245  10  5   9.5   5.2
 11750   4.2  39.6  235  12  6   9.3   5.1 |   4.9  40.8  240  10  5   9.0   5.0
 11500   4.9  40.8  235  12  6   9.5   5.2 |   5.6  42.1  235  10  5   9.5   5.2
 11250   5.6  42.1  230  12  6   8.2   4.5 |   6.2  43.2  230  10  5   8.2   4.5
 11000   6.2  43.2  225  12  6   8.8   4.8 |   6.8  44.2  230  11  6   8.2   4.5
 10750   6.9  44.4  220  12  6  10.2   5.6 |   7.5  45.5  225  11  6   9.1   5.0
 10500   7.7  45.9  215  12  6  10.3   5.6 |   8.2  46.8  220  11  6   9.7   5.3
 10250   8.4  47.1  210  12  6   8.1   4.5 |   8.8  47.8  215  11  6   6.4   3.5
 10000   8.9  48.0  210  12  6   8.7   4.8 |   9.2  48.6  210  12  6   6.9   3.8
  9750   9.7  49.5  210  12  6  11.2   6.2 |   9.9  49.8  210  12  6  10.7   5.9
  9500  10.5  50.9  205  12  6  10.6   5.8 |  10.7  51.3  205  12  6   9.8   5.4
  9250  11.3  52.3  205  12  6  10.0   5.5 |  11.4  52.5  200  12  6   9.5   5.2
  9000  12.0  53.6  205  12  6   9.5   5.2 |  12.1  53.8  200  12  6   9.0   4.9
  8750  12.8  55.0  200  12  6  10.4   5.7 |  12.8  55.0  195  12  6  10.0   5.5
  8500  13.6  56.5  200  12  6  10.6   5.8 |  13.5  56.3  195  12  6  10.4   5.7
  8250  14.3  57.7  200  12  6  10.2   5.6 |  14.3  57.7  195  12  6   9.9   5.4
  8000  15.1  59.2  200  12  6  10.3   5.7 |  15.0  59.0  190  12  6   9.8   5.4
  7750  15.9  60.6  200  12  6   9.3   5.1 |  15.7  60.3  190  12  6   9.2   5.1
  7500  16.5  61.7  195  11  6  10.0   5.5 |  16.3  61.3  190  12  6   7.7   4.2
  7250  17.3  63.1  195  11  6  12.7   7.0 |  16.8  62.2  190  11  6   6.5   3.6
  7000  18.3  64.9  195  11  6  12.6   6.9 |  17.2  63.0  190  10  5   5.8   3.2
  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.