Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

000
UXUS97 KBOU 120102
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1902 MDT Wednesday, October 11, 2017

This forecast is for Thursday, October 12, 2017:

If the trigger temperature of 72.2 F/22.4 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 573 ft/min (2.9 m/s)
   Maximum height of thermals.................. 12166 ft MSL (6824 ft AGL)

Forecast maximum temperature................... 75.0 F/24.3 C
Time of trigger temperature.................... 1245 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 7538 ft MSL (2196 ft AGL)
Thermal soaring outlook for Friday 10/13....... Poor

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak PVA
Potential height of wave....................... 46089 ft MSL (40747 ft AGL)
Wave soaring outlook for Friday 10/13.......... Poor

Remarks... Weak cold front pushing in from the north across denver area around
           1700 MDT

Sunrise/Sunset.................... 07:07:13 / 18:24:27 MDT
Total possible sunshine........... 11 hr 17 min 14 sec (677 min 14 sec)
Altitude of sun at 12:45:50 MDT... 42.44 degrees

Upper air data from numerical model forecast valid on 10/12/2017 at 0600 MDT

Freezing level.................. 14152 ft MSL (8810 ft AGL)
Convective condensation level... 21136 ft MSL (15794 ft AGL)
Lifted condensation level....... 17288 ft MSL (11946 ft AGL)
Lifted index.................... +5.4
K index......................... -6.8

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  -63.8 -82.8   245   39   20   0.8   0.4      M     M       M      M    M
 45000  -62.2 -80.0   245   46   24   2.8   1.5      M     M       M      M    M
 40000  -57.8 -72.0   240   41   21   5.1   2.8      M     M       M      M    M
 38000  -53.5 -64.3   240   39   20   7.3   4.0      M     M       M      M    M
 36000  -49.1 -56.4   240   38   19   7.3   4.0      M     M       M      M    M
 34000  -44.6 -48.3   235   36   19   7.7   4.2      M     M       M      M    M
 32000  -39.9 -39.8   235   34   18   7.7   4.2      M     M       M      M    M
 30000  -34.9 -30.8   235   32   17   7.5   4.1   40.5 104.8    12.6      M    M
 29000  -32.6 -26.7   235   31   16   7.5   4.1   39.6 103.3    12.0      M    M
 28000  -30.4 -22.7   230   30   16   7.5   4.1   38.8 101.9    11.6      M    M
 27000  -28.1 -18.6   230   29   15   7.8   4.3   38.0 100.4    11.1      M    M
 26000  -25.8 -14.4   235   29   15   7.8   4.3   37.2  99.0    10.6      M    M
 25000  -23.5 -10.3   235   28   14   7.8   4.3   36.6  97.8    10.1      M    M
 24000  -21.0  -5.8   235   27   14   8.7   4.8   36.0  96.8     9.8      M    M
 23000  -18.4  -1.1   235   24   13   8.8   4.8   35.6  96.1     9.6      M    M
 22000  -15.7   3.7   230   22   12   8.8   4.8   35.3  95.6     9.4      M    M
 21000  -13.3   8.1   230   21   11   8.0   4.4   34.8  94.7     9.1      M    M
 20000  -10.9  12.4   235   20   10   8.0   4.4   34.2  93.5     8.7      M    M
 19500   -9.7  14.5   235   20   10   8.0   4.4   33.9  93.0     8.5      M    M
 19000   -8.5  16.7   235   19   10   7.7   4.2   33.6  92.6     8.3      M    M
 18500   -7.4  18.7   235   19   10   6.5   3.6   33.2  91.7     7.9      M    M
 18000   -6.4  20.5   240   18    9   6.6   3.6   32.6  90.7     7.5      M    M
 17500   -5.5  22.1   240   18    9   6.0   3.3   32.0  89.7     7.1      M    M
 17000   -4.2  24.4   240   18    9   5.8   3.2   31.0  87.8     6.2      M    M
 16500   -3.3  26.1   245   18    9   5.3   2.9   30.3  86.6     5.6      M    M
 16000   -2.6  27.3   245   17    9   5.2   2.9   29.6  85.2     5.0      M    M
 15500   -1.8  28.8   245   17    9   5.0   2.8   28.8  83.9     4.3      M    M
 15000   -1.1  30.0   245   16    8   4.7   2.6   28.0  82.4     3.6      M    M
 14500   -0.4  31.3   250   15    8   4.7   2.6   27.2  80.9     2.8      M    M
 14000    0.3  32.5   250   14    7   5.3   2.9   26.4  79.5     2.1      M    M
 13500    1.1  34.0   250   13    7   5.1   2.8   25.7  78.2     1.4      M    M
 13000    1.9  35.4   250   12    6   6.6   3.6   25.0  77.0     0.8      M    M
 12500    2.9  37.2   250   10    5   6.4   3.5   24.5  76.1     0.3      M    M
 12000    3.9  39.0   250    8    4   8.2   4.5   24.1  75.3    -0.1    554  2.8
 11500    5.1  41.2   255    7    4   8.4   4.6   23.9  74.9    -0.4    502  2.6
 11000    6.3  43.3   255    6    3   7.6   4.1   23.6  74.5    -0.6    452  2.3
 10500    7.4  45.3   260    5    3   6.8   3.7   23.2  73.8    -1.0    404  2.1
 10250    8.0  46.4   260    5    2  10.1   5.6   23.1  73.5    -1.2    380  1.9
 10000    8.8  47.8   265    4    2  10.4   5.7   23.2  73.8    -1.0    347  1.8
  9750    9.4  48.9   265    4    2   7.1   3.9   23.1  73.5    -1.2    322  1.6
  9500   10.0  50.0   265    3    2   8.5   4.6   22.9  73.3    -1.4    298  1.5
  9250   10.5  50.9   265    3    1   6.3   3.5   22.8  73.0    -1.5    273  1.4
  9000   11.0  51.8   260    2    1   7.0   3.9   22.5  72.5    -1.8    253  1.3
  8750   11.6  52.9   255    2    1   9.2   5.1   22.4  72.3    -1.9    226  1.1
  8500   12.3  54.1   250    2    1   9.0   5.0   22.3  72.2    -2.0    199  1.0
  8250   12.9  55.2   245    2    1   7.6   4.2   22.3  72.1    -2.1    172  0.9
  8000   13.4  56.1   240    2    1   5.6   3.1   22.0  71.6    -2.4    152  0.8
  7750   13.8  56.8   230    2    1   5.8   3.2   21.7  71.0    -2.7    131  0.7
  7500   14.2  57.6   225    2    1   5.8   3.2   21.4  70.5    -3.0    111  0.6
  7250   14.6  58.3   220    3    1   4.9   2.7   21.1  69.9    -3.3     92  0.5
  7000   14.9  58.8   220    3    2   3.7   2.1   20.6  69.1    -3.7     75  0.4
  6750   15.2  59.4   220    4    2   3.3   1.8   20.2  68.3    -4.2     60  0.3
  6500   15.3  59.5   220    4    2  -2.3  -1.3   19.5  67.1    -4.9     50  0.3
  6250   14.7  58.5   215    4    2 -10.7  -5.9   18.3  64.9    -6.2     59  0.3
  6000   13.8  56.8   215    5    3 -12.2  -6.7   16.6  61.9    -7.8     80  0.4
  5750   12.8  55.0   215    6    3 -14.2  -7.8   14.9  58.9    -9.5    101  0.5
  5500   11.2  52.2   215    6    3 -30.4 -16.7   12.7  54.8   -11.9    142  0.7

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

           10/12/2017 at 0900 MDT          |       10/12/2017 at 1200 MDT
                                           |
CAPE...     0.0    LI...       +7.0        | CAPE...     0.0    LI...       +6.3
CINH...    -0.0    K Index...  -8.8        | CINH...     0.0    K Index...  -2.1
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -63.1 -81.6  245  41 21  -0.3  -0.2 | -63.5 -82.3  245  42 22   0.4   0.2
 45000 -62.7 -80.9  245  50 26   3.4   1.9 | -62.1 -79.8  240  51 26   3.7   2.0
 40000 -57.5 -71.5  240  44 23   3.6   2.0 | -56.3 -69.3  240  47 24   5.0   2.7
 38000 -53.1 -63.6  240  42 22   6.9   3.8 | -52.5 -62.5  240  45 23   6.3   3.5
 36000 -48.9 -56.0  240  40 21   6.9   3.8 | -48.7 -55.7  235  43 22   6.3   3.5
 34000 -44.4 -47.9  240  38 20   7.7   4.2 | -44.4 -47.9  235  41 21   7.8   4.3
 32000 -39.8 -39.6  235  36 19   7.7   4.2 | -39.8 -39.6  235  39 20   7.8   4.3
 30000 -35.4 -31.7  235  34 17   7.2   4.0 | -34.5 -30.1  235  36 19   7.9   4.4
 29000 -33.2 -27.8  235  33 17   7.2   4.0 | -32.1 -25.8  235  35 18   7.9   4.4
 28000 -31.0 -23.8  235  32 16   7.2   4.0 | -29.7 -21.5  235  34 18   8.0   4.4
 27000 -28.7 -19.7  235  30 16   8.0   4.4 | -27.5 -17.5  235  33 17   7.4   4.1
 26000 -26.3 -15.3  230  29 15   8.0   4.4 | -25.2 -13.4  235  32 16   7.4   4.1
 25000 -23.9 -11.0  230  28 15   8.0   4.4 | -23.0  -9.4  235  31 16   7.5   4.1
 24000 -21.5  -6.7  225  27 14   8.4   4.6 | -20.7  -5.3  230  30 15   8.0   4.4
 23000 -19.0  -2.2  225  26 13   8.4   4.6 | -18.3  -0.9  230  28 14   8.0   4.4
 22000 -16.4   2.5  225  24 13   8.4   4.6 | -15.9   3.4  225  27 14   8.0   4.4
 21000 -14.1   6.6  225  23 12   7.3   4.0 | -13.8   7.2  225  25 13   6.8   3.7
 20000 -11.3  11.7  225  21 11   7.3   4.0 | -11.7  10.9  230  24 13   6.7   3.7
 19500 -10.2  13.6  225  21 11   7.3   4.0 | -10.7  12.7  230  24 12   6.7   3.7
 19000  -9.1  15.6  230  20 10   6.9   3.8 |  -9.7  14.5  230  23 12   6.7   3.7
 18500  -8.1  17.4  230  20 10   6.7   3.7 |  -8.7  16.3  230  23 12   6.5   3.5
 18000  -7.1  19.2  230  19 10   6.7   3.7 |  -7.8  18.0  235  22 12   6.5   3.6
 17500  -6.1  21.0  230  19 10   6.5   3.6 |  -6.8  19.8  235  22 11   6.3   3.5
 17000  -5.2  22.6  235  19 10   6.5   3.6 |  -5.4  22.3  235  22 11   6.3   3.5
 16500  -4.2  24.4  235  18  9   6.3   3.5 |  -4.5  23.9  240  21 11   5.3   2.9
 16000  -3.3  26.1  240  18  9   6.3   3.4 |  -3.8  25.2  240  21 11   5.0   2.7
 15500  -2.3  27.9  240  18  9   6.2   3.4 |  -3.1  26.4  245  20 11   4.9   2.7
 15000  -1.4  29.5  245  18  9   6.0   3.3 |  -2.4  27.7  245  20 10   4.6   2.5
 14500  -0.5  31.1  245  18  9   6.0   3.3 |  -1.8  28.8  250  19 10   4.7   2.6
 14000   0.4  32.7  245  17  9   6.2   3.4 |  -1.0  30.2  250  18  9   5.6   3.1
 13500   1.3  34.3  250  17  9   6.1   3.3 |  -0.2  31.6  255  17  9   5.5   3.0
 13000   2.2  36.0  250  16  8   6.6   3.6 |   0.7  33.3  255  15  8   6.8   3.7
 12500   3.2  37.8  250  15  8   6.6   3.6 |   1.6  34.9  255  13  7   6.7   3.7
 12000   4.2  39.6  255  14  7   7.0   3.8 |   2.7  36.9  255  11  6   8.0   4.4
 11500   5.2  41.4  255  13  7   7.0   3.9 |   3.9  39.0  255  10  5   8.1   4.4
 11000   6.3  43.3  255  12  6   7.4   4.1 |   5.1  41.2  255   8  4   8.4   4.6
 10500   7.4  45.3  255  10  5   7.5   4.1 |   6.4  43.5  255   6  3   8.4   4.6
 10250   7.9  46.2  255  10  5   7.6   4.2 |   7.0  44.6  255   5  2   8.6   4.7
 10000   8.5  47.3  255   9  5   7.7   4.2 |   7.7  45.9  250   5  2   8.9   4.9
  9750   9.0  48.2  255   9  4   7.7   4.2 |   8.3  46.9  250   4  2   8.9   4.9
  9500   9.6  49.3  255   8  4   7.8   4.3 |   9.0  48.2  245   4  2   9.0   4.9
  9250  10.2  50.4  255   7  4   7.6   4.1 |   9.7  49.5  240   3  2   8.7   4.8
  9000  10.7  51.3  260   6  3   7.5   4.1 |  10.3  50.5  230   2  1   9.0   4.9
  8750  11.3  52.3  255   6  3   7.7   4.2 |  11.0  51.8  225   2  1   9.4   5.1
  8500  11.9  53.4  255   5  3   7.8   4.3 |  11.7  53.1  220   2  1   9.4   5.1
  8250  12.4  54.3  250   5  2   7.3   4.0 |  12.4  54.3  215   2  1   9.0   4.9
  8000  12.9  55.2  250   4  2   6.4   3.5 |  13.0  55.4  200   2  1   8.7   4.8
  7750  13.4  56.1  245   4  2   5.9   3.3 |  13.7  56.7  195   2  1   8.9   4.9
  7500  13.8  56.8  240   3  2   5.8   3.2 |  14.3  57.7  200   2  1   8.8   4.8
  7250  14.2  57.6  235   3  2   6.2   3.4 |  15.0  59.0  200   2  1   7.8   4.3
  7000  14.7  58.5  230   3  2   6.1   3.3 |  15.5  59.9  185   2  1   7.2   4.0
  6750  15.1  59.2  225   3  1   5.0   2.8 |  16.0  60.8  185   2  1   8.3   4.6
  6500  15.3  59.5  220   3  2   0.8   0.4 |  16.7  62.1  190   2  1   8.3   4.5
  6250  15.1  59.2  215   3  2  -4.0  -2.2 |  17.2  63.0  190   2  1   7.5   4.1
  6000  14.8  58.6  210   4  2  -4.1  -2.2 |  17.7  63.9  190   2  1   7.4   4.1
  5750  14.4  57.9  205   4  2  -6.1  -3.4 |  18.2  64.8  185   2  1   7.8   4.3
  5500  13.6  56.5  210   4  2 -16.7  -9.1 |  18.8  65.8  200   2  1  13.0   7.1

           10/12/2017 at 1500 MDT          |       10/12/2017 at 1800 MDT
                                           |
CAPE...     0.0    LI...       +4.6        | CAPE...     0.0    LI...       +3.0
CINH...     0.0    K Index... +12.3        | CINH...     0.0    K Index... +15.9
                                           |
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 -64.9 -84.8  240  43 22   2.8   1.5 | -64.8 -84.6  240  43 22   2.8   1.5
 45000 -60.3 -76.5  240  50 26   3.5   1.9 | -60.3 -76.5  240  52 27   3.4   1.9
 40000 -55.0 -67.0  240  50 26   4.8   2.6 | -55.2 -67.4  245  54 28   4.6   2.5
 38000 -51.4 -60.5  240  49 25   6.1   3.4 | -51.4 -60.5  245  53 27   6.3   3.5
 36000 -47.7 -53.9  240  48 25   6.1   3.4 | -47.6 -53.7  245  52 27   6.3   3.5
 34000 -43.6 -46.5  240  46 24   7.3   4.0 | -43.6 -46.5  245  49 25   7.1   3.9
 32000 -39.2 -38.6  240  43 22   7.3   4.0 | -39.3 -38.7  240  46 24   7.1   3.9
 30000 -34.1 -29.4  240  41 21   7.9   4.4 | -34.4 -29.9  240  42 22   7.4   4.1
 29000 -31.7 -25.1  240  40 21   7.9   4.4 | -32.2 -26.0  240  40 20   7.4   4.1
 28000 -29.3 -20.7  240  40 20   8.0   4.4 | -30.0 -22.0  240  38 19   7.4   4.1
 27000 -27.1 -16.8  240  39 20   7.0   3.9 | -27.8 -18.0  240  37 19   7.1   3.9
 26000 -25.0 -13.0  240  37 19   7.0   3.9 | -25.7 -14.3  240  36 19   7.1   3.9
 25000 -22.9  -9.2  240  36 19   7.0   3.9 | -23.6 -10.5  240  36 18   7.1   3.9
 24000 -20.7  -5.3  235  34 18   7.7   4.2 | -21.5  -6.7  235  35 18   7.3   4.0
 23000 -18.5  -1.3  235  32 16   7.7   4.2 | -19.3  -2.7  235  32 17   7.3   4.0
 22000 -16.2   2.8  230  29 15   7.6   4.2 | -17.1   1.2  235  30 15   7.3   4.0
 21000 -14.1   6.6  230  28 14   6.1   3.3 | -15.1   4.8  235  29 15   6.0   3.3
 20000 -12.3   9.9  235  28 14   6.0   3.3 | -13.3   8.1  240  29 15   6.0   3.3
 19500 -11.4  11.5  240  28 15   6.0   3.3 | -12.4   9.7  240  29 15   6.0   3.3
 19000 -10.5  13.1  240  29 15   6.1   3.3 | -11.5  11.3  240  29 15   6.0   3.3
 18500  -9.8  14.4  245  28 15   4.6   2.5 | -10.8  12.6  245  28 15   4.4   2.4
 18000  -9.1  15.6  245  28 14   4.7   2.6 | -10.1  13.8  245  27 14   4.6   2.5
 17500  -8.4  16.9  245  28 14   4.2   2.3 |  -9.4  15.1  245  25 13   4.8   2.6
 17000  -7.6  18.3  245  25 13   3.7   2.0 |  -8.4  16.9  245  22 11   5.0   2.7
 16500  -7.1  19.2  245  24 12   4.5   2.4 |  -7.6  18.3  240  20 10   6.3   3.4
 16000  -6.4  20.5  245  21 11   4.8   2.7 |  -6.7  19.9  240  18  9   6.7   3.7
 15500  -5.7  21.7  245  19 10   5.6   3.1 |  -5.7  21.7  240  17  9   7.3   4.0
 15000  -4.7  23.5  245  17  9   7.7   4.2 |  -4.5  23.9  240  15  8   8.4   4.6
 14500  -3.6  25.5  245  15  8   7.6   4.2 |  -3.3  26.1  240  13  7   8.5   4.6
 14000  -2.3  27.9  245  14  7   9.5   5.2 |  -2.0  28.4  235  12  6   9.6   5.3
 13500  -0.9  30.4  245  12  6   9.4   5.1 |  -0.6  30.9  235  11  6   9.5   5.2
 13000   0.4  32.7  245  11  6   8.8   4.8 |   0.8  33.4  235  11  6   9.5   5.2
 12500   1.7  35.1  240  10  5   8.7   4.8 |   2.2  36.0  235  10  5   9.5   5.2
 12000   3.0  37.4  240   8  4   9.2   5.1 |   3.6  38.5  235   9  5   9.3   5.1
 11500   4.4  39.9  235   7  4   9.3   5.1 |   5.0  41.0  235   9  5   9.4   5.2
 11000   5.7  42.3  235   7  3   7.9   4.3 |   6.3  43.3  235   8  4   8.0   4.4
 10500   6.9  44.4  230   6  3   6.9   3.8 |   7.5  45.5  235   8  4   7.1   3.9
 10250   7.4  45.3  230   5  3  10.5   5.8 |   8.1  46.6  235   7  4  11.1   6.1
 10000   8.4  47.1  225   5  2  11.1   6.1 |   9.1  48.4  235   7  4  11.5   6.3
  9750   9.0  48.2  225   4  2   7.8   4.3 |   9.7  49.5  235   6  3   7.6   4.2
  9500   9.6  49.3  220   4  2   9.1   5.0 |  10.3  50.5  235   6  3   9.1   5.0
  9250  10.3  50.5  215   3  2   7.3   4.0 |  11.0  51.8  235   6  3   7.0   3.9
  9000  10.8  51.4  210   3  2   7.9   4.3 |  11.5  52.7  230   5  3   7.6   4.2
  8750  11.5  52.7  205   3  1   9.8   5.4 |  12.1  53.8  230   5  2   9.6   5.3
  8500  12.2  54.0  195   2  1   9.3   5.1 |  12.8  55.0  225   4  2   9.2   5.0
  8250  12.9  55.2  185   2  1   9.5   5.2 |  13.5  56.3  225   4  2   8.9   4.9
  8000  13.6  56.5  180   2  1   9.0   4.9 |  14.2  57.6  220   3  2   8.3   4.6
  7750  14.2  57.6  170   2  1   8.5   4.7 |  14.8  58.6  210   3  1   8.3   4.5
  7500  14.9  58.8  160   1  1   8.4   4.6 |  15.4  59.7  205   2  1   8.2   4.5
  7250  15.5  59.9  145   1  1   9.5   5.2 |  16.0  60.8  190   2  1   8.2   4.5
  7000  16.3  61.3  130   1  1  10.2   5.6 |  16.6  61.9  170   1  1   8.1   4.5
  6750  16.9  62.4  115   1  0   8.8   4.8 |  17.2  63.0  140   1  1   7.5   4.1
  6500  17.6  63.7  100   1  0   8.8   4.8 |  17.7  63.9  105   1  1   7.2   4.0
  6250  18.3  64.9  090   1  0  10.0   5.5 |  18.3  64.9  080   1  1   7.3   4.0
  6000  19.0  66.2  080   1  0  10.4   5.7 |  18.8  65.8  060   1  1   7.4   4.0
  5750  19.7  67.5  075   1  0   9.5   5.2 |  19.3  66.7  045   2  1   7.2   3.9
  5500  20.5  68.9  070   1  0  11.6   6.4 |  19.6  67.3  035   2  1   0.5   0.3
________________________________________________________________________________

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 old Stapleton
Airport site in Denver, Colorado at

                   North Latitude:  39 deg 46 min 5.016 sec
                   West Longitude: 104 deg 52 min 9.984 sec
                   Elevation: 5285 feet (1611 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.

CINH (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.