Soaring Guidance
Issued by NWS Denver/Boulder, 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 14 15 16 17 18 19 20 21 22 23 24 25 26
000
UXUS97 KBOU 050119
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1919 MDT Monday, May 4, 2015

This forecast is for Tuesday, May 5, 2015:

If the trigger temperature of 62.2 F/16.8 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 47 ft/min (0.2 m/s)
   Maximum height of thermals.................. 8873 ft MSL (3566 ft AGL)

Forecast maximum temperature................... 61.0 F/16.6 C
Time of trigger temperature.................... 1415 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................. 6783 ft MSL (1477 ft AGL)
Thermal soaring outlook for Wednesday 05/06.... 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....................... 16865 ft MSL (11558 ft AGL)
Wave soaring outlook for Wednesday 05/06....... Poor

Remarks...

Sunrise/Sunset.................... 05:55:34 / 19:56:36 MDT
Total possible sunshine........... 14 hr 1 min 2 sec (841 min 2 sec)
Altitude of sun at 12:56:16 MDT... 66.55 degrees

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

Freezing level.................. 11885 ft MSL (6578 ft AGL)
Convective condensation level... 8753 ft MSL (3446 ft AGL)
Lifted condensation level....... 8831 ft MSL (3524 ft AGL)
Lifted index.................... -0.4
K index......................... +28.8

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  -59.3 -74.7   255   27   14   2.3   1.3      M     M       M      M    M
 45000  -56.3 -69.3   240   29   15  -1.3  -0.7      M     M       M      M    M
 40000  -58.5 -73.3   215   32   17  -1.3  -0.7      M     M       M      M    M
 38000  -56.8 -70.2   200   31   16   4.4   2.4      M     M       M      M    M
 36000  -54.2 -65.6   190   29   15   4.4   2.4      M     M       M      M    M
 34000  -50.4 -58.7   180   28   15   9.3   5.1      M     M       M      M    M
 32000  -44.9 -48.8   180   27   14   9.3   5.1      M     M       M      M    M
 30000  -38.7 -37.7   180   26   13   9.1   5.0   36.8  98.2    15.6      M    M
 29000  -35.9 -32.6   175   26   13   9.1   5.0   36.5  97.7    15.6      M    M
 28000  -33.2 -27.8   175   25   13   9.1   5.0   36.4  97.5    15.7      M    M
 27000  -30.6 -23.1   170   24   13   7.8   4.3   36.0  96.7    15.5      M    M
 26000  -28.3 -18.9   170   22   11   7.8   4.3   35.2  95.3    15.1      M    M
 25000  -26.0 -14.8   170   20   10   7.9   4.3   34.5  94.1    14.7      M    M
 24000  -23.7 -10.7   165   18    9   7.5   4.1   33.8  92.9    14.3      M    M
 23000  -21.4  -6.5   165   16    8   7.6   4.1   32.9  91.3    13.7      M    M
 22000  -19.2  -2.6   160   14    7   7.6   4.2   32.2  89.9    13.2      M    M
 21000  -17.0   1.4   155   13    7   7.2   3.9   31.4  88.5    12.6      M    M
 20000  -14.9   5.2   150   13    7   7.2   4.0   30.5  86.8    11.9      M    M
 19500  -13.8   7.2   150   13    7   7.3   4.0   30.0  86.0    11.6      M    M
 19000  -12.8   9.0   150   13    7   7.3   4.0   29.6  85.3    11.3      M    M
 18500  -11.8  10.8   145   13    7   6.5   3.5   29.2  84.5    10.9      M    M
 18000  -10.8  12.6   140   13    7   6.4   3.5   28.6  83.4    10.4      M    M
 17500   -9.9  14.2   140   13    7   6.4   3.5   28.0  82.4    10.0      M    M
 17000   -9.0  15.8   135   14    7   6.8   3.7   27.5  81.4     9.5      M    M
 16500   -8.0  17.6   130   14    7   6.9   3.8   27.0  80.5     9.1      M    M
 16000   -6.7  19.9   125   15    8   5.5   3.0   26.0  78.9     8.3      M    M
 15500   -5.9  21.4   125   15    8   5.6   3.0   25.3  77.6     7.6      M    M
 15000   -5.1  22.8   120   15    8   6.0   3.3   24.7  76.4     7.1      M    M
 14500   -4.2  24.4   120   14    7   6.0   3.3   24.0  75.3     6.5      M    M
 14000   -3.4  25.9   120   13    7   5.7   3.1   23.4  74.1     5.9      M    M
 13500   -2.6  27.3   125   12    6   5.6   3.1   22.7  72.9     5.3      M    M
 13000   -1.8  28.8   135   11    6   5.7   3.1   22.1  71.7     4.7      M    M
 12500   -0.9  30.4   140   10    5   5.8   3.2   21.4  70.6     4.0      M    M
 12000   -0.1  31.8   150   10    5   5.9   3.2   20.8  69.4     3.4      M    M
 11500    0.7  33.3   155   10    5   5.9   3.3   20.2  68.3     2.8      M    M
 11000    1.6  34.9   160   10    5   6.2   3.4   19.6  67.2     2.2      M    M
 10500    2.5  36.5   155   10    5   5.8   3.2   19.1  66.3     1.7      M    M
 10250    3.0  37.4   150   11    5   9.2   5.0   18.8  65.9     1.4      M    M
 10000    3.7  38.7   145   11    6   8.9   4.9   18.9  66.0     1.5      M    M
  9750    4.1  39.4   145   11    6   5.2   2.9   18.6  65.5     1.2      M    M
  9500    4.5  40.1   145   12    6   6.4   3.5   18.3  64.9     0.8      M    M
  9250    5.0  41.0   140   12    6   5.4   3.0   18.0  64.4     0.6      M    M
  9000    5.3  41.5   140   12    6   4.9   2.7   17.6  63.8     0.2      M    M
  8750    5.7  42.3   135   13    7   5.4   3.0   17.3  63.1    -0.2    238  1.2
  8500    6.1  43.0   135   13    7   5.6   3.0   16.9  62.5    -0.5    219  1.1
  8250    6.5  43.7   135   13    7   5.4   3.0   16.6  61.9    -0.9    200  1.0
  8000    6.8  44.2   130   14    7   5.4   2.9   16.3  61.3    -1.2    181  0.9
  7750    7.2  45.0   125   14    7   5.7   3.1   16.0  60.7    -1.6    162  0.8
  7500    7.6  45.7   120   14    7   6.0   3.3   15.7  60.2    -1.9    142  0.7
  7250    8.0  46.4   115   14    7   5.4   2.9   15.4  59.7    -2.2    123  0.6
  7000    8.4  47.1   110   13    7   4.8   2.6   15.0  59.0    -2.6    105  0.5
  6750    8.7  47.7   100   13    7   3.3   1.8   14.6  58.3    -3.0     88  0.4
  6500    8.9  48.0   090   12    6   1.6   0.9   14.0  57.2    -3.6     76  0.4
  6250    9.0  48.2   080   11    6   1.1   0.6   13.4  56.1    -4.2     65  0.3
  6000    9.0  48.2   065   10    5   0.5   0.3   12.7  54.9    -4.9     56  0.3
  5750    9.1  48.4   045   10    5   1.7   0.9   12.0  53.7    -5.6     47  0.2
  5500    9.4  48.9   025    9    5   5.7   3.1   11.6  52.8    -6.0     32  0.2

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

           05/05/2015 at 0900 MDT          |       05/05/2015 at 1200 MDT
                                           |
K index... +26.8  LI... +272.1             | K index... +23.9  LI... +274.3
CAPE... +125.0  CIN... -3.5                | CAPE... +6.2  CIN... -0.9
                                           |
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 -58.7 -73.7  245  22 11   2.1   1.2 | -58.2 -72.8  235  22 11   2.2   1.2
 45000 -56.0 -68.8  225  27 14  -2.7  -1.5 | -55.5 -67.9  220  27 14  -3.6  -2.0
 40000 -60.2 -76.4  205  28 15  -2.6  -1.4 | -60.9 -77.6  195  32 16  -3.3  -1.8
 38000 -57.9 -72.2  200  35 18   6.4   3.5 | -58.2 -72.8  190  37 19   7.6   4.2
 36000 -54.1 -65.4  205  43 22   6.4   3.5 | -53.6 -64.5  185  43 22   7.6   4.2
 34000 -49.7 -57.5  200  44 23   9.0   5.0 | -48.8 -55.8  185  45 23   8.8   4.8
 32000 -43.6 -46.5  195  34 17   9.0   4.9 | -42.9 -45.2  180  40 21   8.8   4.8
 30000 -38.2 -36.8  185  28 14   9.1   5.0 | -37.6 -35.7  175  37 19   9.0   5.0
 29000 -35.5 -31.9  180  27 14   9.1   5.0 | -34.9 -30.8  175  35 18   9.0   5.0
 28000 -32.8 -27.0  170  26 14   9.1   5.0 | -32.2 -26.0  170  33 17   9.0   5.0
 27000 -30.2 -22.4  165  26 13   8.3   4.6 | -29.6 -21.3  170  31 16   8.1   4.5
 26000 -27.7 -17.9  165  25 13   8.4   4.6 | -27.1 -16.8  165  29 15   8.2   4.5
 25000 -25.2 -13.4  165  25 13   8.4   4.6 | -24.7 -12.5  155  26 13   8.2   4.5
 24000 -22.7  -8.9  160  25 13   7.2   4.0 | -22.3  -8.1  150  24 12   6.9   3.8
 23000 -20.6  -5.1  160  24 12   7.2   3.9 | -20.3  -4.5  150  23 12   6.8   3.7
 22000 -18.4  -1.1  155  23 12   7.2   4.0 | -18.3  -0.9  150  23 12   6.8   3.7
 21000 -16.4   2.5  155  22 12   6.1   3.3 | -16.3   2.7  145  22 11   6.9   3.8
 20000 -14.5   5.9  150  23 12   6.3   3.5 | -14.3   6.3  145  21 11   6.9   3.8
 19500 -13.6   7.5  150  23 12   6.3   3.5 | -13.3   8.1  145  20 11   6.9   3.8
 19000 -12.7   9.1  150  23 12   6.4   3.5 | -12.3   9.9  145  20 10   6.9   3.8
 18500 -11.8  10.8  150  23 12   6.7   3.7 | -11.3  11.7  145  20 10   6.5   3.5
 18000 -10.8  12.6  150  22 11   6.8   3.7 | -10.4  13.3  140  19 10   6.3   3.5
 17500  -9.8  14.4  150  21 11   6.8   3.7 |  -9.5  14.9  140  19 10   6.3   3.5
 17000  -8.9  16.0  150  20 10   6.6   3.6 |  -8.1  17.4  140  19 10   6.5   3.6
 16500  -7.4  18.7  150  19 10   6.6   3.6 |  -7.2  19.0  140  19 10   6.4   3.5
 16000  -6.5  20.3  150  17  9   6.4   3.5 |  -6.3  20.7  140  19 10   5.6   3.1
 15500  -5.6  21.9  150  16  8   6.5   3.6 |  -5.5  22.1  140  19 10   5.7   3.1
 15000  -4.8  23.4  150  14  7   5.2   2.8 |  -4.7  23.5  140  19 10   5.0   2.7
 14500  -4.0  24.8  150  13  7   5.3   2.9 |  -4.0  24.8  140  19 10   5.0   2.7
 14000  -3.3  26.1  150  12  6   6.0   3.3 |  -3.2  26.2  140  19 10   5.3   2.9
 13500  -2.4  27.7  150  12  6   6.2   3.4 |  -2.4  27.7  140  19 10   5.4   2.9
 13000  -1.5  29.3  145  11  6   7.1   3.9 |  -1.7  28.9  140  20 10   5.6   3.1
 12500  -0.4  31.3  140  11  6   7.6   4.2 |  -0.8  30.6  140  20 10   5.8   3.2
 12000   0.6  33.1  140  11  6   7.5   4.1 |   0.1  32.2  140  19 10   5.8   3.2
 11500   1.7  35.1  140  10  5   7.3   4.0 |   0.9  33.6  140  19 10   5.8   3.2
 11000   2.7  36.9  145   8  4   5.7   3.2 |   1.7  35.1  135  18  9   5.3   2.9
 10500   3.3  37.9  160   8  4   3.9   2.1 |   2.4  36.3  135  17  9   4.5   2.5
 10250   3.6  38.5  165   8  4   4.1   2.3 |   2.7  36.9  135  17  9   5.0   2.7
 10000   3.9  39.0  180   8  4   4.5   2.5 |   3.0  37.4  135  16  8   5.2   2.9
  9750   4.2  39.6  180   9  4   4.4   2.4 |   3.4  38.1  140  15  8   5.0   2.7
  9500   4.5  40.1  185   9  5   4.4   2.4 |   3.7  38.7  140  14  7   4.8   2.6
  9250   4.8  40.6  185  10  5   4.3   2.3 |   4.0  39.2  140  13  6   5.4   3.0
  9000   5.1  41.2  190  10  5   4.1   2.3 |   4.5  40.1  145  11  6   7.8   4.3
  8750   5.4  41.7  185  10  5   4.4   2.4 |   5.1  41.2  145  11  5   7.7   4.2
  8500   5.7  42.3  180  11  5   4.5   2.5 |   5.5  41.9  145  10  5   6.5   3.6
  8250   6.0  42.8  180  11  6   4.4   2.4 |   6.0  42.8  150   9  5   6.7   3.7
  8000   6.3  43.3  170  11  5   3.9   2.1 |   6.4  43.5  150   8  4   5.6   3.1
  7750   6.6  43.9  165  10  5   3.4   1.9 |   6.8  44.2  155   7  3   4.5   2.5
  7500   6.8  44.2  155   9  5   3.3   1.8 |   7.1  44.8  160   5  3   4.6   2.5
  7250   7.1  44.8  145   8  4   3.2   1.7 |   7.4  45.3  165   4  2   3.9   2.2
  7000   7.3  45.1  135   7  4   2.9   1.6 |   7.6  45.7  175   3  1   3.1   1.7
  6750   7.5  45.5  115   6  3   3.0   1.6 |   7.8  46.0  220   1  1   2.8   1.5
  6500   7.7  45.9  090   5  3   3.2   1.7 |   8.0  46.4  295   2  1   3.3   1.8
  6250   7.9  46.2  065   4  2   3.8   2.1 |   8.4  47.1  315   3  1   7.5   4.1
  6000   8.2  46.8  035   4  2   4.0   2.2 |   9.1  48.4  315   4  2  10.3   5.6
  5750   8.5  47.3  005   4  2   4.4   2.4 |   9.8  49.6  320   4  2   8.6   4.7
  5500   8.9  48.0  340   4  2   7.5   4.1 |  10.5  50.9  320   5  2  12.6   6.9

           05/05/2015 at 1500 MDT          |       05/05/2015 at 1800 MDT
                                           |
K index... +27.3  LI... +271.7             | K index... +21.6  LI... +273.8
CAPE... +335.0  CIN... -83.5               | CAPE... +110.1  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 -57.5 -71.5  230  23 12   2.7   1.5 | -57.6 -71.7  230  23 12   2.8   1.5
 45000 -54.3 -65.7  225  28 15  -4.0  -2.2 | -54.3 -65.7  220  22 11  -4.0  -2.2
 40000 -60.4 -76.7  185  33 17  -3.8  -2.1 | -60.4 -76.7  160  22 11  -3.9  -2.1
 38000 -57.8 -72.0  180  33 17   7.8   4.3 | -57.8 -72.0  155  24 12   7.9   4.4
 36000 -53.1 -63.6  175  31 16   7.8   4.3 | -53.1 -63.6  155  26 13   7.9   4.4
 34000 -47.3 -53.1  170  28 15   9.5   5.2 | -47.3 -53.1  155  27 14   9.4   5.2
 32000 -41.6 -42.9  160  26 13   9.5   5.2 | -41.7 -43.1  150  28 14   9.4   5.2
 30000 -36.2 -33.2  150  24 12   8.5   4.7 | -36.2 -33.2  150  28 14   8.7   4.8
 29000 -33.6 -28.5  145  24 12   8.5   4.7 | -33.6 -28.5  145  28 14   8.7   4.8
 28000 -31.1 -24.0  135  23 12   8.5   4.7 | -31.0 -23.8  145  28 14   8.8   4.8
 27000 -28.6 -19.5  130  23 12   7.9   4.3 | -28.5 -19.3  140  27 14   7.6   4.2
 26000 -26.3 -15.3  130  23 12   7.9   4.4 | -26.2 -15.2  140  27 14   7.8   4.3
 25000 -23.9 -11.0  125  23 12   8.0   4.4 | -23.9 -11.0  135  27 14   7.8   4.3
 24000 -21.6  -6.9  125  23 12   7.2   4.0 | -21.6  -6.9  135  28 14   7.4   4.1
 23000 -19.5  -3.1  120  23 12   7.0   3.8 | -19.4  -2.9  130  27 14   7.2   3.9
 22000 -17.5   0.5  120  23 12   7.0   3.9 | -17.3   0.9  130  25 13   7.2   3.9
 21000 -15.5   4.1  120  23 12   6.0   3.3 | -15.3   4.5  125  24 12   6.4   3.5
 20000 -13.7   7.3  120  21 11   6.0   3.3 | -13.4   7.9  125  22 11   6.2   3.4
 19500 -12.8   9.0  120  20 10   6.0   3.3 | -12.5   9.5  130  20 10   6.3   3.4
 19000 -12.0  10.4  120  20 10   6.0   3.3 | -11.6  11.1  130  19 10   6.2   3.4
 18500 -11.1  12.0  120  19 10   6.1   3.4 | -10.7  12.7  130  18  9   6.0   3.3
 18000 -10.2  13.6  120  18  9   6.2   3.4 |  -9.9  14.2  130  16  8   5.6   3.1
 17500  -8.8  16.2  125  17  9   5.9   3.2 |  -8.6  16.5  130  14  7   5.6   3.1
 17000  -8.0  17.6  130  16  8   5.7   3.1 |  -7.8  18.0  135  13  7   5.5   3.0
 16500  -7.2  19.0  130  15  8   5.6   3.1 |  -7.0  19.4  135  12  6   5.6   3.1
 16000  -6.4  20.5  135  15  8   5.4   2.9 |  -6.2  20.8  140  11  6   5.4   2.9
 15500  -5.6  21.9  135  14  7   5.4   3.0 |  -5.5  22.1  150  11  6   5.4   3.0
 15000  -4.9  23.2  140  14  7   5.4   3.0 |  -4.7  23.5  155  11  5   5.4   3.0
 14500  -4.1  24.6  140  14  7   5.4   3.0 |  -3.9  25.0  160  11  5   5.4   3.0
 14000  -3.3  26.1  140  14  7   5.2   2.9 |  -3.1  26.4  170  11  6   5.2   2.9
 13500  -2.6  27.3  145  15  8   5.1   2.8 |  -2.4  27.7  170  11  6   4.8   2.6
 13000  -1.9  28.6  145  16  8   5.2   2.8 |  -1.7  28.9  175  11  6   4.6   2.5
 12500  -1.1  30.0  145  16  8   5.3   2.9 |  -1.2  29.8  175  11  5   3.3   1.8
 12000  -0.4  31.3  140  17  9   6.0   3.3 |  -0.7  30.7  175  10  5   3.3   1.8
 11500   0.7  33.3  135  17  9   8.4   4.6 |  -0.3  31.5  175  11  5   2.3   1.3
 11000   1.9  35.4  130  17  8   7.9   4.3 |   0.0  32.0  170  11  6   2.5   1.4
 10500   2.9  37.2  125  15  8   6.3   3.5 |   0.6  33.1  170  11  6   4.6   2.5
 10250   3.3  37.9  120  15  8   6.0   3.3 |   0.9  33.6  170  11  6   5.5   3.0
 10000   3.7  38.7  115  14  7   5.8   3.2 |   1.5  34.7  175  11  6   8.6   4.7
  9750   4.1  39.4  115  13  7   6.6   3.6 |   2.2  36.0  175  10  5  10.6   5.8
  9500   4.6  40.3  110  12  6   6.7   3.7 |   2.9  37.2  180   9  5  10.7   5.9
  9250   5.1  41.2  110  11  6   7.3   4.0 |   3.7  38.7  180   8  4  11.4   6.3
  9000   5.6  42.1  110  11  5   4.7   2.6 |   4.5  40.1  185   7  4   8.7   4.8
  8750   5.8  42.4  105  10  5   4.4   2.4 |   4.9  40.8  190   6  3   6.2   3.4
  8500   6.3  43.3  100   9  4   6.8   3.7 |   5.4  41.7  200   6  3   7.1   3.9
  8250   6.7  44.1  100   8  4   6.1   3.4 |   5.9  42.6  215   5  2   6.9   3.8
  8000   7.2  45.0  090   6  3   7.2   3.9 |   6.4  43.5  230   4  2   7.0   3.8
  7750   7.7  45.9  085   5  3   6.7   3.7 |   6.9  44.4  250   5  2   6.0   3.3
  7500   8.1  46.6  075   5  2   5.5   3.0 |   7.3  45.1  265   6  3   5.3   2.9
  7250   8.5  47.3  070   4  2   6.5   3.5 |   7.6  45.7  275   7  3   5.5   3.0
  7000   9.0  48.2  060   4  2   8.3   4.6 |   8.0  46.4  280   8  4   5.2   2.9
  6750   9.6  49.3  050   3  2   8.7   4.8 |   8.4  47.1  280   9  5   5.6   3.1
  6500  10.2  50.4  040   3  2   7.9   4.3 |   8.8  47.8  280  10  5   5.3   2.9
  6250  10.8  51.4  030   3  1   9.3   5.1 |   9.1  48.4  280  10  5   7.4   4.1
  6000  11.6  52.9  020   3  1  10.9   6.0 |   9.8  49.6  280  10  5  10.6   5.8
  5750  12.3  54.1  010   3  1   9.7   5.3 |  10.5  50.9  275   9  5  10.3   5.6
  5500  13.1  55.6  005   2  1  11.7   6.4 |  11.2  52.2  275   8  4  10.5   5.8
________________________________________________________________________________

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.

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.