Soaring Guidance
Issued by NWS Grand Junction, CO

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591
UXUS97 KGJT 201331
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0731 MDT Thursday, July 20, 2017

This forecast is for Thursday, July 20, 2017:

If the trigger temperature of 85.6 F/29.8 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 958 ft/min (4.9 m/s)
   Maximum height of thermals.................. 15906 ft MSL (11067 ft AGL)

Forecast maximum temperature................... 95.0 F/35.5 C
Time of trigger temperature.................... 1030 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 10164 ft MSL (5325 ft AGL)
Thermal soaring outlook for Friday 07/21....... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:04:43 / 20:36:30 MDT
Total possible sunshine........... 14 hr 31 min 47 sec (871 min 47 sec)
Altitude of sun at 13:20:29 MDT... 71.36 degrees

Upper air data from rawinsonde observation taken on 07/20/2017 at 0600 MDT

Freezing level.................. 17486 ft MSL (12647 ft AGL)
Convective condensation level... 14309 ft MSL (9470 ft AGL)
Lifted condensation level....... 14820 ft MSL (9980 ft AGL)
Lifted index.................... -4.5
K index......................... +30.7

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  -67.8 -90.0   210   24   12   9.3   5.1   79.4 174.9    25.9      M    M
 45000  -62.2 -80.0   220   19   10  -0.1  -0.1   64.4 147.9    18.4      M    M
 40000  -50.3 -58.5   235   13    7   6.4   3.5   60.1 140.2    16.8      M    M
 38000  -46.0 -50.8   195   10    5   8.8   4.8   57.9 136.2    15.7      M    M
 36000  -39.9 -39.8   160   15    8   7.3   4.0   57.2 135.0    15.7      M    M
 34000  -35.7 -32.3   215   16    8   7.7   4.2   54.9 130.8    14.4      M    M
 32000  -31.2 -24.2   190   16    8   1.5   0.8   53.0 127.4    13.3      M    M
 30000  -26.8 -16.2   220   12    6   7.8   4.3   51.1 124.1    12.1      M    M
 29000  -25.2 -13.4   210   12    6   7.8   4.3   49.3 120.8    11.0      M    M
 28000  -22.7  -8.9   200   12    6   8.0   4.4   48.8 119.8    10.7      M    M
 27000  -20.8  -5.4   200   10    5   0.9   0.5   47.5 117.5     9.8      M    M
 26000  -19.5  -3.1   200    8    4   5.6   3.0   45.7 114.3     8.3      M    M
 25000  -17.3   0.9   205    6    3   8.2   4.5   44.7 112.5     7.6      M    M
 24000  -14.8   5.4   190   10    5   7.1   3.9   44.0 111.1     7.3      M    M
 23000  -12.7   9.1   185   14    7   7.5   4.1   42.9 109.3     6.5      M    M
 22000  -10.2  13.6   180   19   10   8.8   4.8   42.5 108.5     6.2      M    M
 21000   -7.6  18.3   185   15    8   8.8   4.8   42.1 107.7     5.9      M    M
 20000   -4.6  23.7   195   11    6   6.0   3.3   41.4 106.5     5.3      M    M
 19500   -3.8  25.2   210   10    5   1.5   0.8   40.5 104.8     4.6      M    M
 19000   -3.1  26.4   220   10    5   8.6   4.7   39.7 103.4     3.9      M    M
 18500   -2.0  28.4   230   11    6   8.4   4.6   39.4 102.9     3.6      M    M
 18000   -0.9  30.4   235   12    6   7.0   3.9   39.0 102.3     3.3      M    M
 17500    0.1  32.2   225   11    6   5.5   3.0   38.5 101.3     2.8      M    M
 17000    0.6  33.1   225   11    6   3.9   2.1   37.6  99.6     1.8      M    M
 16500    1.0  33.8   245   13    6   4.0   2.2   36.6  97.9     0.8      M    M
 16000    1.7  35.1   260   15    8   7.5   4.1   35.9  96.6     0.0      M    M
 15500    2.8  37.0   255   15    8   8.0   4.4   35.6  96.0    -0.4    914  4.6
 15000    3.9  39.0   250   14    7   8.5   4.7   35.3  95.5    -0.8    866  4.4
 14500    5.2  41.4   250   14    7   9.0   4.9   35.2  95.3    -0.9    814  4.1
 14000    6.5  43.7   245   14    7   8.9   4.9   35.0  95.1    -1.0    758  3.8
 13500    7.9  46.2   250   13    7   8.2   4.5   34.9  94.8    -1.1    702  3.6
 13000    8.7  47.7   260   12    6   5.3   2.9   34.3  93.8    -1.8    663  3.4
 12500    9.8  49.6   255   14    7   9.4   5.2   34.0  93.2    -2.2    616  3.1
 12000   11.1  52.0   250   15    8   9.1   5.0   33.9  93.0    -2.3    561  2.8
 11500   12.5  54.5   245   15    8   9.1   5.0   33.8  92.8    -2.4    505  2.6
 11000   13.8  56.8   245   14    7   9.0   4.9   33.7  92.6    -2.5    450  2.3
 10500   15.2  59.4   240   14    7   7.6   4.2   33.6  92.4    -2.6    394  2.0
 10250   15.7  60.3   240   14    7   6.0   3.3   33.3  91.9    -2.9    373  1.9
 10000   16.1  61.0   240   14    7   5.7   3.1   33.0  91.4    -3.2    351  1.8
  9750   16.3  61.3   225   12    6  -0.0  -0.0   32.5  90.5    -3.7    338  1.7
  9500   16.2  61.2   200   11    6   3.5   1.9   31.7  89.1    -4.6    334  1.7
  9250   16.8  62.2   180   12    6   9.4   5.2   31.6  88.9    -4.7    309  1.6
  9000   17.4  63.3   160   15    8   7.6   4.2   31.5  88.6    -4.9    284  1.4
  8750   18.0  64.4   160   16    8   9.0   4.9   31.3  88.4    -5.0    260  1.3
  8500   18.5  65.3   160   18    9   5.3   2.9   31.2  88.2    -5.2    235  1.2
  8250   18.5  65.3   160   19   10  -4.2  -2.3   30.5  86.9    -5.9    227  1.2
  8000   18.1  64.6   160   21   11  -4.5  -2.5   29.3  84.7    -7.2    234  1.2
  7750   18.0  64.4   160   22   11   4.6   2.5   28.5  83.3    -7.9    228  1.2
  7500   18.6  65.5   160   22   11   7.7   4.2   28.3  83.0    -8.2    204  1.0
  7250   19.1  66.4   165   23   12   7.8   4.3   28.1  82.6    -8.4    181  0.9
  7000   19.6  67.3   165   24   12   4.4   2.4   27.9  82.3    -8.6    158  0.8
  6750   19.6  67.3   160   21   11  -0.5  -0.3   27.3  81.1    -9.4    151  0.8
  6500   19.6  67.3   150   18    9   5.2   2.9   26.6  80.0   -10.1    143  0.7
  6250   20.2  68.4   140   16    8   9.4   5.2   26.6  79.8   -10.2    117  0.6
  6000   20.8  69.4   125   14    7   8.3   4.6   26.5  79.6   -10.4     91  0.5
  5750   21.5  70.7   115   13    7   8.6   4.7   26.4  79.5   -10.5     66  0.3
  5500   22.1  71.8   115   13    6   8.5   4.6   26.3  79.3   -10.6     40  0.2
  5250   22.7  72.9   105   12    6   8.8   4.8   26.2  79.2   -10.8     14  0.1
  5000   23.2  73.8   100   11    6   2.9   1.6   26.0  78.8   -11.0      M    M

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

           07/20/2017 at 0900 MDT          |       07/20/2017 at 1200 MDT
                                           |
K index... +31.4  LI... -3.0               | K index... +31.7  LI... -3.7
CAPE... +766.4  CIN... -8.6                | CAPE... +1033.6  CIN... -22.9
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -66.5 -87.7  235  16  8   2.5   1.4 | -66.1 -87.0  215  16  8   1.9   1.0
 45000 -60.3 -76.5  220  17  9   6.6   3.6 | -60.6 -77.1  210  15  8   6.7   3.7
 40000 -50.1 -58.2  195  17  9   7.6   4.2 | -49.7 -57.5  200  15  8   7.7   4.2
 38000 -45.0 -49.0  185  14  7   7.6   4.2 | -45.1 -49.2  185  14  7   7.7   4.2
 36000 -40.4 -40.7  180  12  6   7.9   4.3 | -40.5 -40.9  175  13  7   7.6   4.2
 34000 -35.7 -32.3  180  12  6   7.9   4.3 | -35.9 -32.6  170  12  6   7.6   4.2
 32000 -30.9 -23.6  180  11  6   7.6   4.2 | -31.3 -24.3  160  10  5   7.7   4.2
 30000 -26.8 -16.2  180  12  6   7.0   3.8 | -27.1 -16.8  175  10  5   7.0   3.8
 29000 -24.7 -12.5  180  12  6   7.0   3.8 | -25.1 -13.2  180  11  5   7.0   3.8
 28000 -22.6  -8.7  180  12  6   6.9   3.8 | -22.5  -8.5  185  10  5   6.8   3.7
 27000 -20.5  -4.9  180  12  6   6.9   3.8 | -20.5  -4.9  185  10  5   6.8   3.7
 26000 -18.4  -1.1  185  11  6   6.9   3.8 | -18.5  -1.3  190   9  5   6.9   3.8
 25000 -16.4   2.5  190  10  5   6.8   3.7 | -16.5   2.3  195   9  5   6.5   3.6
 24000 -14.4   6.1  200  10  5   6.7   3.7 | -14.6   5.7  205  10  5   6.5   3.6
 23000 -12.4   9.7  210  11  6   6.7   3.7 | -12.7   9.1  220  10  5   6.6   3.6
 22000 -10.4  13.3  220  12  6   6.8   3.7 | -10.8  12.6  225  12  6   7.5   4.1
 21000  -7.9  17.8  220  14  7   7.0   3.9 |  -8.5  16.7  225  13  7   7.5   4.1
 20000  -5.9  21.4  220  16  8   7.2   4.0 |  -6.3  20.7  225  15  8   7.4   4.1
 19500  -5.0  23.0  225  17  9   6.7   3.7 |  -5.2  22.6  225  16  8   7.0   3.9
 19000  -4.0  24.8  225  16  8   6.5   3.6 |  -4.3  24.3  225  14  7   6.6   3.6
 18500  -3.0  26.6  230  15  8   6.5   3.5 |  -3.4  25.9  230  13  7   6.8   3.7
 18000  -2.2  28.0  235  14  7   5.2   2.8 |  -2.5  27.5  230  13  6   6.2   3.4
 17500  -1.4  29.5  240  14  7   5.3   2.9 |  -1.6  29.1  235  12  6   6.2   3.4
 17000  -0.6  30.9  245  14  7   6.0   3.3 |  -0.6  30.9  240  12  6   6.2   3.4
 16500   0.2  32.4  250  14  7   6.4   3.5 |   0.3  32.5  240  12  6   6.4   3.5
 16000   1.1  34.0  255  14  7   6.8   3.7 |   1.2  34.2  245  12  6   6.3   3.4
 15500   2.2  36.0  255  14  7   8.1   4.4 |   2.2  36.0  250  12  6   8.0   4.4
 15000   3.4  38.1  255  14  7   8.0   4.4 |   3.4  38.1  255  12  6   7.8   4.3
 14500   4.5  40.1  255  13  7   8.8   4.8 |   4.5  40.1  255  12  6   8.3   4.6
 14000   5.7  42.3  250  12  6   8.9   4.9 |   5.7  42.3  255  12  6   8.5   4.7
 13500   6.9  44.4  245  11  6   8.5   4.6 |   7.5  45.5  255  12  6   8.6   4.7
 13000   8.1  46.6  240  10  5   8.5   4.6 |   8.7  47.7  250  11  6   8.7   4.8
 12500   9.2  48.6  235   9  4   8.6   4.7 |   9.9  49.8  245  11  6   9.0   4.9
 12000  10.4  50.7  230   8  4   8.6   4.7 |  11.1  52.0  245   9  5   9.0   5.0
 11500  11.7  53.1  225   7  4   8.5   4.6 |  12.4  54.3  240   8  4   8.8   4.8
 11000  12.9  55.2  225   6  3   8.1   4.4 |  13.6  56.5  235   8  4   9.3   5.1
 10500  14.1  57.4  225   6  3   4.2   2.3 |  14.6  58.3  235   7  3   4.5   2.5
 10250  14.2  57.6  225   5  3   4.9   2.7 |  15.1  59.2  235   6  3   8.9   4.9
 10000  14.9  58.8  225   5  3  10.5   5.8 |  15.8  60.4  235   6  3  11.0   6.0
  9750  15.6  60.1  220   5  2   9.4   5.2 |  16.6  61.9  240   6  3   9.9   5.4
  9500  16.3  61.3  220   5  2   8.2   4.5 |  17.2  63.0  240   5  3   6.7   3.7
  9250  16.8  62.2  220   4  2   6.5   3.6 |  17.7  63.9  245   5  2   7.2   4.0
  9000  17.3  63.1  220   4  2   7.7   4.3 |  18.3  64.9  245   4  2   9.9   5.4
  8750  17.9  64.2  215   4  2   8.2   4.5 |  19.0  66.2  245   4  2   9.0   4.9
  8500  18.5  65.3  215   4  2   7.5   4.1 |  19.6  67.3  250   4  2   8.2   4.5
  8250  19.0  66.2  210   4  2   6.9   3.8 |  20.2  68.4  250   4  2   8.1   4.5
  8000  19.6  67.3  200   4  2   7.1   3.9 |  20.8  69.4  250   3  2   9.7   5.3
  7750  20.1  68.2  195   4  2   6.9   3.8 |  21.6  70.9  250   3  2  10.2   5.6
  7500  20.6  69.1  185   5  2   5.7   3.1 |  22.3  72.1  250   3  2   9.8   5.4
  7250  21.0  69.8  180   5  3   4.8   2.6 |  23.0  73.4  250   3  2   9.7   5.3
  7000  21.4  70.5  175   6  3   5.8   3.2 |  23.8  74.8  250   3  2  10.2   5.6
  6750  21.8  71.2  170   6  3   5.4   2.9 |  24.6  76.3  255   3  2  11.1   6.1
  6500  22.0  71.6  165   5  3   3.1   1.7 |  25.4  77.7  255   3  2  11.1   6.1
  6250  22.2  72.0  155   4  2   1.9   1.0 |  26.2  79.2  255   3  2  11.4   6.3
  6000  22.3  72.1  140   4  2   3.9   2.1 |  27.1  80.8  255   3  2  10.0   5.5
  5750  22.8  73.0  130   3  2  11.7   6.4 |  27.8  82.0  255   3  2  12.8   7.0
  5500  24.0  75.2  125   3  2  19.1  10.5 |  29.0  84.2  255   3  2  17.1   9.4
  5250     M     M    M   M  M     M     M |  30.2  86.4  255   4  2  13.8   7.6
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           07/20/2017 at 1500 MDT          |       07/20/2017 at 1800 MDT
                                           |
K index... +31.2  LI... -3.5               | K index... +30.2  LI... -3.5
CAPE... +786.6  CIN... -32.6               | CAPE... +789.0  CIN... -38.7
                                           |
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 -65.7 -86.3  220  20 10   2.1   1.2 | -65.9 -86.6  235  18  9   2.4   1.3
 45000 -60.0 -76.0  215  19 10   6.7   3.7 | -60.1 -76.2  235  16  8   6.3   3.4
 40000 -49.3 -56.7  210  14  7   7.1   3.9 | -49.8 -57.6  220  11  6   7.7   4.2
 38000 -45.1 -49.2  190  13  7   7.1   3.9 | -45.2 -49.4  190  15  8   7.7   4.2
 36000 -40.8 -41.4  175  14  7   7.5   4.1 | -40.5 -40.9  180  20 10   7.4   4.1
 34000 -36.3 -33.3  175  16  8   7.5   4.1 | -36.1 -33.0  180  20 10   7.3   4.0
 32000 -31.8 -25.2  175  19 10   8.2   4.5 | -31.7 -25.1  185  19 10   8.0   4.4
 30000 -27.2 -17.0  180  16  8   7.8   4.3 | -27.4 -17.3  195  18  9   7.2   4.0
 29000 -24.3 -11.7  190  15  8   7.8   4.3 | -24.7 -12.5  205  17  9   7.3   4.0
 28000 -22.1  -7.8  195  13  7   6.8   3.7 | -22.6  -8.7  210  16  8   7.6   4.2
 27000 -20.1  -4.2  200  12  6   6.8   3.7 | -20.3  -4.5  210  15  8   7.6   4.2
 26000 -18.1  -0.6  210  11  5   6.9   3.8 | -18.1  -0.6  215  13  7   7.7   4.2
 25000 -16.1   3.0  220  10  5   6.4   3.5 | -15.9   3.4  220  12  6   6.7   3.7
 24000 -14.3   6.3  220  10  5   6.4   3.5 | -13.9   7.0  220  11  6   6.6   3.6
 23000 -12.4   9.7  225  10  5   6.4   3.5 | -12.0  10.4  220  11  6   6.7   3.7
 22000 -10.5  13.1  225  10  5   6.8   3.7 | -10.1  13.8  220  10  5   6.2   3.4
 21000  -8.6  16.5  225  10  5   6.8   3.7 |  -8.3  17.1  230  11  6   6.2   3.4
 20000  -6.6  20.1  230  11  6   6.9   3.8 |  -6.5  20.3  235  11  6   6.3   3.4
 19500  -5.6  21.9  230  11  6   7.2   4.0 |  -5.6  21.9  235  11  6   6.6   3.6
 19000  -4.5  23.9  230  11  6   7.7   4.2 |  -4.6  23.7  240  11  6   7.3   4.0
 18500  -3.3  26.1  235  11  6   7.7   4.2 |  -3.5  25.7  245  11  6   7.4   4.1
 18000  -2.2  28.0  240  11  5   7.6   4.2 |  -2.5  27.5  250  10  5   6.6   3.6
 17500  -1.1  30.0  240  10  5   7.6   4.2 |  -1.5  29.3  250  10  5   6.6   3.6
 17000  -0.0  32.0  245  10  5   7.4   4.1 |  -0.6  30.9  255   9  5   7.0   3.8
 16500   1.0  33.8  245   9  5   7.0   3.9 |   0.6  33.1  255   9  5   7.8   4.3
 16000   2.0  35.6  250   9  5   7.0   3.8 |   1.7  35.1  255   9  4   7.7   4.2
 15500   3.1  37.6  255   9  5   7.6   4.2 |   2.9  37.2  260   8  4   9.1   5.0
 15000   4.2  39.6  255   9  5   7.5   4.1 |   4.3  39.7  260   8  4   9.0   5.0
 14500   5.3  41.5  255   9  5   8.0   4.4 |   5.6  42.1  260   8  4   8.5   4.7
 14000   7.1  44.8  260   9  5   8.2   4.5 |   6.8  44.2  260   8  4   8.4   4.6
 13500   8.3  46.9  260   9  5   8.3   4.6 |   8.6  47.5  255   7  4   8.4   4.6
 13000   9.5  49.1  265   9  5   8.3   4.6 |   9.8  49.6  250   7  3   8.4   4.6
 12500  10.7  51.3  265   9  5   8.4   4.6 |  11.0  51.8  245   6  3   8.7   4.8
 12000  11.9  53.4  265   9  5   8.5   4.7 |  12.3  54.1  240   6  3   8.8   4.8
 11500  13.1  55.6  265   9  5   8.4   4.6 |  13.5  56.3  235   6  3   8.8   4.8
 11000  14.4  57.9  260   8  4   8.8   4.8 |  14.8  58.6  230   6  3   9.2   5.0
 10500  15.4  59.7  260   8  4   5.4   3.0 |  15.9  60.6  220   6  3   5.3   2.9
 10250  15.9  60.6  255   8  4   8.9   4.9 |  16.4  61.5  215   6  3   8.8   4.8
 10000  16.6  61.9  255   7  4  10.5   5.7 |  17.1  62.8  210   6  3  11.0   6.0
  9750  17.3  63.1  255   7  4  10.1   5.5 |  17.9  64.2  200   6  3  10.6   5.8
  9500  17.9  64.2  250   7  4   7.7   4.2 |  18.6  65.5  195   6  3   8.1   4.4
  9250  18.4  65.1  250   7  4   8.5   4.7 |  19.1  66.4  190   6  3   7.9   4.3
  9000  19.2  66.6  250   7  4  11.1   6.1 |  19.8  67.6  185   7  3   9.9   5.5
  8750  20.0  68.0  250   7  4  10.3   5.6 |  20.5  68.9  185   7  4   9.3   5.1
  8500  20.7  69.3  250   7  4   9.8   5.4 |  21.2  70.2  180   7  4   8.3   4.6
  8250  21.4  70.5  250   7  4   9.4   5.2 |  21.7  71.1  175   8  4   7.6   4.2
  8000  22.1  71.8  250   7  4   9.3   5.1 |  22.3  72.1  170   9  4   8.0   4.4
  7750  22.8  73.0  250   7  4   9.3   5.1 |  22.9  73.2  170   9  5   8.1   4.5
  7500  23.5  74.3  250   7  4   9.6   5.3 |  23.5  74.3  165  10  5   8.2   4.5
  7250  24.2  75.6  245   7  4   9.5   5.2 |  24.0  75.2  165  10  5   8.3   4.5
  7000  24.9  76.8  245   7  4  10.0   5.5 |  24.6  76.3  165  11  6   8.4   4.6
  6750  25.7  78.3  245   7  4  10.5   5.8 |  25.2  77.4  165  11  6   9.7   5.3
  6500  26.4  79.5  245   7  4  10.4   5.7 |  26.0  78.8  165  11  6  10.8   5.9
  6250  27.2  81.0  245   7  4  10.5   5.8 |  26.8  80.2  165  11  6  11.0   6.0
  6000  27.9  82.2  245   7  4  10.0   5.5 |  27.6  81.7  165  11  5  10.4   5.7
  5750  28.7  83.7  245   7  3  12.4   6.8 |  28.3  82.9  165  10  5  10.0   5.5
  5500  29.8  85.6  245   7  3  15.3   8.4 |  29.1  84.4  165  10  5  10.3   5.6
  5250  30.8  87.4  245   7  3  13.1   7.2 |  29.9  85.8  165  10  5  10.0   5.5
  5000     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 at Walker Field in Grand
Junction, Colorado at

                   North Latitude:  39 deg 07 min 00.001 sec
                   West Longitude: 108 deg 31 min 59.998 sec
                   Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado.  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



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