Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 201238
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0638 MDT Tuesday, June 20, 2017

This forecast is for Tuesday, June 20, 2017:

If the trigger temperature of 90.7 F/32.6 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1329 ft/min (6.8 m/s)
   Maximum height of thermals.................. 19108 ft MSL (14269 ft AGL)

Forecast maximum temperature................... 101.0 F/38.8 C
Time of trigger temperature.................... None
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................. 13802 ft MSL (8963 ft AGL)
Thermal soaring outlook for Wednesday 06/21.... Excellent

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

Remarks...

Sunrise/Sunset.................... 05:48:23 / 20:43:08 MDT
Total possible sunshine........... 14 hr 54 min 46 sec (894 min 46 sec)
Altitude of sun at 13:15:52 MDT... 74.29 degrees

Upper air data from rawinsonde observation taken on 06/20/2017 at 0600 MDT

Freezing level.................. 17386 ft MSL (12547 ft AGL)
Convective condensation level... 20668 ft MSL (15829 ft AGL)
Lifted condensation level....... 20408 ft MSL (15569 ft AGL)
Lifted index.................... -0.9
K index......................... +2.1

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  -69.0 -92.2   305   33   17   2.9   1.6   78.4 173.1    23.3      M    M
 45000  -61.1 -78.0   310   42   22   5.1   2.8   67.1 152.7    17.9      M    M
 40000  -52.5 -62.5   290   32   16   8.4   4.6   57.5 135.6    12.8      M    M
 38000  -50.4 -58.7   270   30   15   8.2   4.5   52.0 125.7     9.4      M    M
 36000  -45.0 -49.0   285   32   17   9.2   5.0   50.4 122.7     8.5      M    M
 34000  -39.6 -39.3   285   34   17   8.0   4.4   49.8 121.6     8.3      M    M
 32000  -35.2 -31.4   285   35   18   7.2   3.9   47.8 118.1     7.0      M    M
 30000  -29.8 -21.6   285   33   17   8.6   4.7   47.1 116.8     6.6      M    M
 29000  -27.5 -17.5   290   32   16   8.2   4.5   46.4 115.5     6.2      M    M
 28000  -24.9 -12.8   290   29   15   8.6   4.7   45.9 114.6     5.8      M    M
 27000  -22.4  -8.3   285   27   14   7.9   4.3   45.4 113.7     5.5      M    M
 26000  -20.3  -4.5   275   26   13   6.2   3.4   44.3 111.7     4.8      M    M
 25000  -18.4  -1.1   260   26   13   5.7   3.1   43.0 109.3     3.7      M    M
 24000  -16.7   1.9   255   25   13   7.4   4.1   41.4 106.6     2.5      M    M
 23000  -14.2   6.4   255   22   11   8.3   4.6   40.9 105.6     2.1      M    M
 22000  -11.7  10.9   255   19   10   8.9   4.9   40.4 104.8     1.7      M    M
 21000   -9.1  15.6   260   17    9   7.7   4.2   40.1 104.1     1.4      M    M
 20000   -6.9  19.6   260   14    7   7.7   4.2   39.3 102.7     0.7      M    M
 19500   -5.2  22.6   280   15    7   7.6   4.2   38.7 101.7     0.2      M    M
 19000   -4.1  24.6   285   16    8   8.0   4.4   38.3 101.0    -0.2   1308  6.6
 18500   -2.8  27.0   290   16    8   9.1   5.0   38.1 100.6    -0.4   1254  6.4
 18000   -1.4  29.5   295   16    8   9.1   5.0   38.0 100.4    -0.5   1198  6.1
 17500   -0.1  31.8   295   17    9   9.1   5.0   37.9 100.1    -0.6   1143  5.8
 17000    1.3  34.3   300   17    9   9.1   5.0   37.8 100.0    -0.7   1088  5.5
 16500    2.6  36.7   300   18    9   9.0   4.9   37.7  99.8    -0.8   1032  5.2
 16000    4.0  39.2   305   18    9   8.3   4.6   37.6  99.7    -0.9    977  5.0
 15500    5.0  41.0   310   20   10   6.6   3.6   37.1  98.9    -1.3    931  4.7
 15000    6.0  42.8   315   21   11   6.8   3.7   36.6  97.9    -1.8    887  4.5
 14500    7.2  45.0   310   20   10   6.6   3.6   36.2  97.2    -2.1    837  4.3
 14000    8.0  46.4   310   19   10   6.2   3.4   35.6  96.1    -2.8    798  4.1
 13500    8.7  47.7   310   16    8   6.6   3.6   35.0  95.0    -3.5    760  3.9
 13000    9.6  49.3   305   14    7   8.2   4.5   34.6  94.3    -4.1    720  3.7
 12500   11.0  51.8   300   11    6   8.6   4.7   34.4  94.0    -4.2    664  3.4
 12000   12.3  54.1   295    9    5   8.7   4.8   34.3  93.7    -4.3    609  3.1
 11500   13.7  56.7   295    7    4   8.7   4.8   34.1  93.4    -4.5    553  2.8
 11000   15.0  59.0   300    5    3   8.6   4.7   33.9  93.1    -4.6    498  2.5
 10500   16.2  61.2   305    3    2   8.8   4.8   33.7  92.7    -5.0    449  2.3
 10250   16.8  62.2   305    2    1   9.0   4.9   33.7  92.6    -5.0    422  2.1
 10000   17.5  63.5   300    2    1   8.9   4.9   33.6  92.5    -5.1    395  2.0
  9750   18.1  64.6   295    1    1   8.9   4.9   33.5  92.4    -5.2    368  1.9
  9500   18.8  65.8   275    1    0   9.0   4.9   33.5  92.3    -5.3    341  1.7
  9250   19.5  67.1   000    0    0   8.9   4.9   33.4  92.2    -5.4    313  1.6
  9000   20.1  68.2   150    1    0   9.0   5.0   33.4  92.1    -5.4    286  1.5
  8750   20.8  69.4   135    1    1   8.6   4.7   33.3  92.0    -5.5    259  1.3
  8500   21.4  70.5   125    2    1  10.3   5.6   33.2  91.8    -5.6    232  1.2
  8250   22.1  71.8   120    2    1   4.1   2.2   33.2  91.7    -5.7    205  1.0
  8000   22.1  71.8   115    3    1   0.1   0.0   32.4  90.4    -6.5    198  1.0
  7750   22.3  72.1   140    4    2   5.1   2.8   31.9  89.4    -7.0    184  0.9
  7500   22.7  72.9   150    6    3   8.1   4.4   31.6  89.0    -7.3    163  0.8
  7250   23.2  73.8   160    8    4  -0.1  -0.1   31.4  88.5    -7.6    143  0.7
  7000   22.8  73.0   165   10    5  -4.6  -2.5   30.2  86.4    -8.8    147  0.7
  6750   22.8  73.0   160    9    5   3.0   1.6   29.5  85.1    -9.5    140  0.7
  6500   23.0  73.4   150    7    4   3.9   2.1   29.0  84.2   -10.0    125  0.6
  6250   23.3  73.9   135    6    3   3.4   1.9   28.5  83.4   -10.5    109  0.6
  6000   23.6  74.5   115    6    3   4.4   2.4   28.1  82.6   -11.0     94  0.5
  5750   23.8  74.8   110    6    3   0.9   0.5   27.6  81.7   -11.5     79  0.4
  5500   23.5  74.3   115    6    3  -9.5  -5.2   26.6  79.8   -12.6     81  0.4
  5250   22.6  72.7   120    5    3 -10.6  -5.8   25.0  76.9   -14.2    100  0.5
  5000   21.9  71.4   125    5    3 -10.1  -5.5   23.5  74.4   -15.7    113  0.6

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

           06/20/2017 at 0900 MDT          |       06/20/2017 at 1200 MDT
                                           |
K index... +15.0  LI... +2.3               | K index... +15.1  LI... +1.1
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -66.3 -87.3  325  32 17   1.8   1.0 | -65.2 -85.4  330  29 15   1.3   0.7
 45000 -61.8 -79.2  310  36 19   5.7   3.1 | -61.5 -78.7  320  37 19   5.2   2.8
 40000 -52.7 -62.9  300  31 16   6.4   3.5 | -52.9 -63.2  305  30 15   6.9   3.8
 38000 -48.9 -56.0  290  29 15   6.4   3.5 | -48.8 -55.8  295  28 14   6.9   3.8
 36000 -45.0 -49.0  285  28 14   7.6   4.1 | -44.6 -48.3  285  27 14   7.4   4.0
 34000 -39.9 -39.8  285  27 14   8.6   4.7 | -39.9 -39.8  280  28 14   7.9   4.3
 32000 -34.7 -30.5  285  27 14   9.0   4.9 | -35.2 -31.4  275  28 14   8.1   4.5
 30000 -30.1 -22.2  285  25 13   7.8   4.3 | -30.3 -22.5  275  28 14   8.2   4.5
 29000 -27.7 -17.9  285  24 12   7.8   4.3 | -27.8 -18.0  275  27 14   8.2   4.5
 28000 -25.4 -13.7  285  24 12   7.3   4.0 | -24.9 -12.8  275  27 14   7.3   4.0
 27000 -22.7  -8.9  280  23 12   7.3   4.0 | -22.7  -8.9  275  26 13   7.3   4.0
 26000 -20.5  -4.9  275  23 12   7.3   4.0 | -20.5  -4.9  275  25 13   7.3   4.0
 25000 -18.4  -1.1  275  23 12   6.9   3.8 | -18.4  -1.1  275  25 13   6.9   3.8
 24000 -16.3   2.7  275  23 12   6.8   3.7 | -16.3   2.7  275  25 13   6.9   3.8
 23000 -14.3   6.3  275  22 11   6.8   3.8 | -14.3   6.3  280  25 13   6.9   3.8
 22000 -12.2  10.0  280  22 11   7.8   4.3 | -12.3   9.9  280  25 13   7.4   4.0
 21000  -9.9  14.2  285  22 11   7.8   4.3 | -10.1  13.8  285  24 12   7.4   4.1
 20000  -7.7  18.1  290  21 11   7.8   4.3 |  -8.0  17.6  285  23 12   7.6   4.2
 19500  -6.5  20.3  290  21 11   8.2   4.5 |  -6.9  19.6  285  23 12   8.2   4.5
 19000  -5.3  22.5  295  22 11   8.5   4.7 |  -5.6  21.9  290  22 11   8.9   4.9
 18500  -4.1  24.6  295  22 11   8.6   4.7 |  -4.3  24.3  290  22 11   8.9   4.9
 18000  -2.8  27.0  295  22 11   8.8   4.8 |  -2.9  26.8  290  21 11   9.2   5.0
 17500  -1.5  29.3  295  22 11   8.8   4.8 |  -1.5  29.3  290  21 11   9.2   5.0
 17000  -0.1  31.8  295  21 11   8.6   4.7 |  -0.1  31.8  290  20 10   9.0   4.9
 16500   1.1  34.0  295  20 10   8.4   4.6 |   1.2  34.2  290  19 10   8.7   4.8
 16000   2.3  36.1  290  19 10   8.5   4.6 |   2.5  36.5  290  19 10   8.7   4.8
 15500   3.5  38.3  290  19 10   8.4   4.6 |   3.7  38.7  290  17  9   8.4   4.6
 15000   4.8  40.6  290  18  9   8.3   4.6 |   5.0  41.0  290  16  8   8.4   4.6
 14500   6.0  42.8  285  17  9   9.3   5.1 |   6.2  43.2  290  15  8   8.6   4.7
 14000   7.5  45.5  285  17  9   9.5   5.2 |   7.5  45.5  290  14  7   8.6   4.7
 13500   9.5  49.1  285  16  8   8.4   4.6 |   9.4  48.9  285  13  7   8.9   4.9
 13000  10.8  51.4  280  15  8   8.6   4.7 |  10.7  51.3  285  12  6   8.9   4.9
 12500  12.1  53.8  280  15  7   8.2   4.5 |  12.0  53.6  290  11  6   8.2   4.5
 12000  13.3  55.9  280  14  7   8.2   4.5 |  13.2  55.8  295  11  6   8.1   4.5
 11500  14.5  58.1  275  13  7   7.8   4.3 |  14.4  57.9  295  11  5   8.7   4.8
 11000  15.6  60.1  275  12  6   8.0   4.4 |  15.7  60.3  300  10  5   9.4   5.2
 10500  16.5  61.7  270  11  6   3.9   2.1 |  16.7  62.1  300   9  5   4.4   2.4
 10250  16.9  62.4  270  11  5   6.8   3.8 |  17.1  62.8  295   9  5   8.8   4.8
 10000  17.5  63.5  270  10  5   9.3   5.1 |  17.9  64.2  295   8  4  10.6   5.8
  9750  18.1  64.6  270   9  5   8.4   4.6 |  18.6  65.5  295   8  4   9.6   5.3
  9500  18.6  65.5  265   8  4   6.0   3.3 |  19.2  66.6  290   7  4   5.9   3.2
  9250  19.0  66.2  265   7  4   5.4   3.0 |  19.6  67.3  285   7  3   6.4   3.5
  9000  19.5  67.1  265   6  3   7.0   3.8 |  20.3  68.5  280   6  3   9.4   5.2
  8750  19.9  67.8  260   5  2   6.5   3.6 |  21.0  69.8  275   5  3   8.3   4.5
  8500  20.4  68.7  255   4  2   5.6   3.1 |  21.5  70.7  270   5  3   7.0   3.8
  8250  20.8  69.4  240   3  2   5.2   2.8 |  22.0  71.6  260   5  2   6.6   3.6
  8000  21.2  70.2  225   3  1   5.3   2.9 |  22.5  72.5  260   4  2   7.5   4.1
  7750  21.5  70.7  205   3  2   4.3   2.4 |  23.1  73.6  255   4  2   8.7   4.7
  7500  21.8  71.2  190   3  2   2.9   1.6 |  23.7  74.7  250   4  2   9.7   5.3
  7250  22.0  71.6  180   4  2   3.2   1.7 |  24.5  76.1  250   4  2   9.9   5.4
  7000  22.2  72.0  170   5  2   1.4   0.8 |  25.2  77.4  250   4  2   9.8   5.4
  6750  22.3  72.1  160   5  3   1.8   1.0 |  25.9  78.6  250   4  2  10.5   5.8
  6500  22.5  72.5  155   4  2   3.9   2.1 |  26.7  80.1  250   4  2  11.0   6.1
  6250  22.7  72.9  145   4  2   3.5   1.9 |  27.5  81.5  250   4  2  11.0   6.1
  6000  22.9  73.2  135   3  2   3.0   1.7 |  28.4  83.1  250   4  2  10.6   5.8
  5750  23.3  73.9  125   3  1   8.0   4.4 |  29.2  84.6  250   4  2  13.5   7.4
  5500  24.1  75.4  125   3  1  13.3   7.3 |  30.4  86.7  250   4  2  16.9   9.2
  5250  25.0  77.0  125   3  1   9.2   5.1 |  31.5  88.7  250   4  2  14.3   7.8
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           06/20/2017 at 1500 MDT          |       06/20/2017 at 1800 MDT
                                           |
K index... +15.4  LI... +0.8               | K index... +20.0  LI... +0.4
CAPE... +30.9  CIN... -76.1                | CAPE... +46.0  CIN... -88.1
                                           |
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 -65.1 -85.2  325  22 11   2.0   1.1 | -65.8 -86.4  315  22 12   2.8   1.6
 45000 -60.4 -76.7  315  34 17   4.7   2.6 | -60.0 -76.0  320  30 16   5.3   2.9
 40000 -52.7 -62.9  300  30 15   7.1   3.9 | -51.6 -60.9  305  26 13   7.0   3.8
 38000 -48.4 -55.1  295  29 15   7.1   3.9 | -47.4 -53.3  300  27 14   7.0   3.8
 36000 -44.1 -47.4  290  29 15   7.3   4.0 | -43.2 -45.8  295  28 14   7.3   4.0
 34000 -39.6 -39.3  280  29 15   7.5   4.1 | -38.6 -37.5  285  26 13   7.7   4.2
 32000 -35.1 -31.2  275  30 15   7.7   4.2 | -33.9 -29.0  280  25 13   8.3   4.6
 30000 -29.7 -21.5  275  28 14   8.0   4.4 | -29.1 -20.4  270  24 13   7.1   3.9
 29000 -27.4 -17.3  275  27 14   7.9   4.4 | -27.5 -17.5  265  24 13   7.1   3.9
 28000 -25.1 -13.2  275  27 14   7.1   3.9 | -24.9 -12.8  265  24 12   6.7   3.7
 27000 -23.0  -9.4  270  27 14   7.1   3.9 | -22.9  -9.2  265  23 12   6.7   3.7
 26000 -20.9  -5.6  270  27 14   7.2   3.9 | -20.9  -5.6  260  22 11   6.7   3.7
 25000 -18.7  -1.7  270  28 14   7.4   4.1 | -18.9  -2.0  260  21 11   6.8   3.7
 24000 -16.5   2.3  275  26 14   7.5   4.1 | -16.8   1.8  260  19 10   6.9   3.8
 23000 -14.3   6.3  280  25 13   7.5   4.1 | -14.8   5.4  255  17  9   6.9   3.8
 22000 -12.0  10.4  285  24 13   7.9   4.3 | -12.8   9.0  255  15  8   8.4   4.6
 21000  -9.7  14.5  290  23 12   7.9   4.3 | -10.3  13.5  255  13  7   8.6   4.7
 20000  -7.4  18.7  295  21 11   8.0   4.4 |  -7.8  18.0  255  10  5   8.6   4.7
 19500  -6.2  20.8  295  20 10   8.2   4.5 |  -6.5  20.3  255   9  5   8.8   4.8
 19000  -5.0  23.0  295  19 10   8.5   4.6 |  -5.2  22.6  260   8  4   9.1   5.0
 18500  -3.8  25.2  295  19 10   8.5   4.7 |  -3.8  25.2  265   8  4   9.1   5.0
 18000  -2.5  27.5  295  19 10   8.8   4.8 |  -2.5  27.5  270   7  4   9.1   5.0
 17500  -1.2  29.8  295  18  9   8.8   4.8 |  -1.1  30.0  275   7  4   9.1   5.0
 17000   0.1  32.2  290  17  9   8.9   4.9 |   0.2  32.4  285   7  3   9.1   5.0
 16500   1.4  34.5  290  16  8   9.0   4.9 |   1.6  34.9  290   7  3   9.1   5.0
 16000   2.7  36.9  290  16  8   9.0   4.9 |   2.9  37.2  295   7  3   9.0   5.0
 15500   4.1  39.4  290  15  8   9.0   5.0 |   4.3  39.7  305   7  4   9.3   5.1
 15000   5.4  41.7  285  14  7   9.0   4.9 |   6.4  43.5  310   8  4   9.2   5.1
 14500   7.5  45.5  285  13  7   9.3   5.1 |   7.7  45.9  315   8  4   8.6   4.7
 14000   8.9  48.0  285  12  6   9.3   5.1 |   9.0  48.2  315   9  4   8.6   4.7
 13500  10.2  50.4  285  12  6   9.0   4.9 |  10.3  50.5  320   9  5   9.0   5.0
 13000  11.6  52.9  285  11  6   9.0   5.0 |  11.6  52.9  320  10  5   9.0   4.9
 12500  12.9  55.2  285  11  5   8.8   4.8 |  13.0  55.4  320  10  5   9.0   5.0
 12000  14.2  57.6  285  10  5   8.8   4.8 |  14.3  57.7  315  11  6   9.1   5.0
 11500  15.5  59.9  285   9  5   8.8   4.8 |  15.7  60.3  315  12  6   8.6   4.7
 11000  16.8  62.2  285   9  5   9.4   5.1 |  16.9  62.4  315  13  6   8.8   4.8
 10500  17.9  64.2  285   8  4   6.0   3.3 |  17.9  64.2  310  13  7   5.0   2.7
 10250  18.5  65.3  285   8  4   9.6   5.2 |  18.4  65.1  310  14  7   7.8   4.3
 10000  19.2  66.6  285   7  4  10.1   5.5 |  19.0  66.2  310  15  8   9.5   5.2
  9750  20.0  68.0  285   7  4   9.8   5.4 |  19.7  67.5  305  15  8   9.4   5.1
  9500  20.6  69.1  290   7  3   7.1   3.9 |  20.3  68.5  305  16  8   6.5   3.6
  9250  21.1  70.0  290   6  3   7.2   4.0 |  20.7  69.3  305  17  9   6.6   3.6
  9000  21.7  71.1  285   6  3   9.1   5.0 |  21.3  70.3  305  17  9   9.2   5.0
  8750  22.3  72.1  285   6  3   8.8   4.8 |  22.0  71.6  305  18  9   8.5   4.7
  8500  22.9  73.2  285   6  3   9.9   5.4 |  22.6  72.7  300  19 10   8.6   4.7
  8250  23.7  74.7  285   6  3  10.3   5.6 |  23.2  73.8  300  19 10   8.6   4.7
  8000  24.4  75.9  285   6  3  10.1   5.5 |  23.9  75.0  300  20 10   8.5   4.7
  7750  25.2  77.4  285   6  3  10.1   5.5 |  24.5  76.1  300  20 10   8.8   4.8
  7500  25.9  78.6  285   5  3  10.0   5.5 |  25.2  77.4  300  21 11   9.6   5.3
  7250  26.7  80.1  280   5  3  10.0   5.5 |  25.9  78.6  300  21 11  10.3   5.6
  7000  27.4  81.3  280   5  3  10.1   5.6 |  26.6  79.9  300  21 11   9.1   5.0
  6750  28.2  82.8  280   5  3  10.6   5.8 |  27.3  81.1  300  21 11   9.2   5.0
  6500  29.0  84.2  280   5  3  10.8   5.9 |  28.1  82.6  300  21 11  10.7   5.9
  6250  29.8  85.6  280   5  3  11.0   6.1 |  28.9  84.0  295  20 10  11.2   6.1
  6000  30.6  87.1  275   5  3  10.1   5.5 |  29.7  85.5  295  20 10   9.6   5.3
  5750  31.4  88.5  275   5  3  13.7   7.5 |  30.4  86.7  295  18 10  10.1   5.5
  5500  32.7  90.9  280   5  3  18.1  10.0 |  31.3  88.3  295  18  9  12.6   6.9
  5250  33.9  93.0  280   5  3  14.7   8.1 |  32.1  89.8  300  17  9  10.6   5.8
  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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