Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 221236
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0636 MDT Thursday, June 22, 2017

This forecast is for Thursday, June 22, 2017:

If the trigger temperature of 91.4 F/33.0 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1648 ft/min (8.4 m/s)
   Maximum height of thermals.................. 23338 ft MSL (18499 ft AGL)

Forecast maximum temperature................... 101.0 F/38.8 C
Time of trigger temperature.................... 1200 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 14632 ft MSL (9793 ft AGL)
Thermal soaring outlook for Friday 06/23....... Excellent

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

Remarks...

Sunrise/Sunset.................... 05:48:50 / 20:43:34 MDT
Total possible sunshine........... 14 hr 54 min 44 sec (894 min 44 sec)
Altitude of sun at 13:16:18 MDT... 74.28 degrees

Upper air data from rawinsonde observation taken on 06/22/2017 at 0600 MDT

Freezing level.................. 16664 ft MSL (11825 ft AGL)
Convective condensation level... 18945 ft MSL (14106 ft AGL)
Lifted condensation level....... 20191 ft MSL (15351 ft AGL)
Lifted index.................... -3.6
K index......................... +18.1

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  -66.4 -87.5   270   25   13   5.9   3.2   82.7 180.8    25.8      M    M
 45000  -58.9 -74.0   260   43   22   4.2   2.3   70.7 159.3    20.2      M    M
 40000  -51.8 -61.2   260   57   30   3.3   1.8   58.9 138.0    13.7      M    M
 38000  -47.3 -53.1   260   57   30   9.3   5.1   55.9 132.5    12.0      M    M
 36000  -43.0 -45.4   255   55   28   6.5   3.6   53.6 128.6    10.8      M    M
 34000  -38.6 -37.5   265   51   26   6.6   3.6   51.5 124.7     9.5      M    M
 32000  -35.4 -31.7   270   48   25   5.2   2.8   47.9 118.2     7.1      M    M
 30000  -32.6 -26.7   280   40   21  10.3   5.6   43.9 111.0     4.2      M    M
 29000  -29.7 -21.5   275   41   21   9.4   5.2   43.7 110.6     4.1      M    M
 28000  -26.9 -16.4   275   42   22   9.9   5.4   43.6 110.5     4.1      M    M
 27000  -25.2 -13.4   270   44   23   7.2   3.9   42.1 107.7     2.9      M    M
 26000  -22.7  -8.9   270   45   23   8.4   4.6   41.5 106.7     2.5      M    M
 25000  -20.3  -4.5   265   47   24   5.0   2.7   41.0 105.8     2.1      M    M
 24000  -18.6  -1.5   255   41   21   6.1   3.3   39.4 103.0     0.8      M    M
 23000  -16.9   1.6   260   37   19   6.1   3.3   38.2 100.8    -0.4   1829  9.3
 22000  -14.9   5.2   260   33   17   7.0   3.8   37.0  98.6    -1.4   1742  8.9
 21000  -12.3   9.9   265   30   15   9.3   5.1   36.7  98.0    -1.7   1633  8.3
 20000   -8.9  16.0   275   26   13   9.5   5.2   36.5  97.7    -1.9   1493  7.6
 19500   -8.0  17.6   270   25   13   6.2   3.4   35.9  96.6    -2.5   1452  7.4
 19000   -6.6  20.1   270   23   12   9.6   5.3   35.8  96.5    -2.6   1395  7.1
 18500   -5.1  22.8   270   22   11   9.7   5.3   35.8  96.5    -2.6   1337  6.8
 18000   -3.7  25.3   270   20   10   9.7   5.3   35.9  96.6    -2.6   1278  6.5
 17500   -2.2  28.0   270   21   11   9.7   5.3   35.8  96.5    -2.7   1220  6.2
 17000   -0.8  30.6   270   21   11   9.7   5.3   35.8  96.4    -2.7   1162  5.9
 16500    0.7  33.3   270   22   11   9.8   5.4   35.8  96.5    -2.8   1103  5.6
 16000    2.1  35.8   270   22   11   9.3   5.1   35.8  96.5    -2.8   1045  5.3
 15500    3.5  38.3   270   20   10   9.2   5.1   35.7  96.3    -2.9    989  5.0
 15000    4.9  40.8   270   19   10   9.2   5.1   35.7  96.2    -3.0    933  4.7
 14500    6.2  43.2   270   17    9   9.2   5.1   35.6  96.1    -3.0    877  4.5
 14000    7.6  45.7   270   16    8   9.2   5.1   35.6  96.0    -3.1    821  4.2
 13500    9.0  48.2   265   16    8   9.2   5.1   35.5  95.8    -3.2    765  3.9
 13000   10.4  50.7   260   16    8   9.2   5.1   35.4  95.6    -3.3    709  3.6
 12500   11.7  53.1   255   17    9   9.2   5.1   35.3  95.5    -3.4    653  3.3
 12000   13.1  55.6   250   17    9   9.2   5.1   35.2  95.4    -3.5    597  3.0
 11500   14.5  58.1   250   16    8   9.2   5.1   35.1  95.2    -3.7    541  2.7
 11000   15.9  60.6   250   15    8   9.2   5.1   35.0  95.0    -3.8    485  2.5
 10500   17.2  63.0   250   13    7   9.2   5.1   34.9  94.8    -3.9    429  2.2
 10250   17.9  64.2   250   13    7   8.8   4.8   34.8  94.7    -4.0    401  2.0
 10000   18.5  65.3   245   12    6   7.6   4.2   34.7  94.5    -4.1    376  1.9
  9750   19.0  66.2   240   12    6   7.1   3.9   34.5  94.1    -4.3    353  1.8
  9500   19.6  67.3   235   11    6   7.2   4.0   34.3  93.7    -4.6    330  1.7
  9250   20.1  68.2   225   11    6   7.2   3.9   34.1  93.4    -4.8    306  1.6
  9000   20.6  69.1   220   11    6   7.1   3.9   33.9  93.1    -5.0    283  1.4
  8750   21.1  70.0   210   11    5   7.4   4.1   33.7  92.7    -5.2    260  1.3
  8500   21.7  71.1   200   11    5   6.4   3.5   33.5  92.3    -5.4    237  1.2
  8250   22.1  71.8   185   11    6   5.0   2.7   33.2  91.7    -5.8    218  1.1
  8000   22.4  72.3   175   12    6   4.9   2.7   32.8  91.1    -6.2    200  1.0
  7750   22.8  73.0   170   11    6   4.9   2.7   32.4  90.4    -6.5    182  0.9
  7500   23.1  73.6   160   11    5   4.9   2.7   32.1  89.7    -6.9    164  0.8
  7250   23.5  74.3   150   10    5   4.9   2.7   31.7  89.0    -7.3    146  0.7
  7000   23.8  74.8   140   10    5   5.1   2.8   31.3  88.4    -7.7    128  0.6
  6750   24.2  75.6   135   10    5   4.2   2.3   31.0  87.7    -8.1    110  0.6
  6500   24.4  75.9   130   10    5   0.9   0.5   30.4  86.7    -8.7     97  0.5
  6250   24.3  75.7   120   10    5  -2.3  -1.3   29.6  85.3    -9.5     92  0.5
  6000   24.2  75.6   115   11    6   3.1   1.7   28.8  83.8   -10.3     87  0.4
  5750   24.7  76.5   115   10    5   8.3   4.6   28.6  83.5   -10.6     64  0.3
  5500   25.3  77.5   115    8    4   7.7   4.2   28.4  83.2   -10.8     40  0.2
  5250   25.9  78.6   115    7    4   7.0   3.8   28.3  82.9   -11.0     15  0.1
  5000   25.8  78.4   110    5    3 -14.3  -7.8   27.5  81.5   -11.8     10  0.0

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

           06/22/2017 at 0900 MDT          |       06/22/2017 at 1200 MDT
                                           |
K index... +13.6  LI... +0.5               | K index... +13.7  LI... -0.1
CAPE... +49.8  CIN... -28.9                | CAPE... +93.4  CIN... -87.9
                                           |
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 -64.4 -83.9  270  30 15   2.1   1.2 | -64.4 -83.9  265  33 17   2.5   1.4
 45000 -59.4 -74.9  270  44 23   6.2   3.4 | -59.0 -74.2  265  47 24   6.2   3.4
 40000 -49.8 -57.6  270  55 29   6.0   3.3 | -49.5 -57.1  270  56 29   5.1   2.8
 38000 -46.2 -51.2  275  54 28   6.0   3.3 | -46.4 -51.5  275  52 27   5.1   2.8
 36000 -42.6 -44.7  275  53 28   5.9   3.2 | -43.4 -46.1  280  49 25   4.9   2.7
 34000 -38.7 -37.7  280  49 25   6.7   3.7 | -39.4 -38.9  285  44 23   6.9   3.8
 32000 -34.7 -30.5  285  43 22   6.6   3.6 | -35.2 -31.4  290  39 20   6.8   3.7
 30000 -30.8 -23.4  285  40 21   6.3   3.5 | -31.1 -24.0  290  34 17   6.8   3.8
 29000 -28.9 -20.0  285  39 20   6.3   3.5 | -29.1 -20.4  295  31 16   6.8   3.8
 28000 -27.1 -16.8  285  38 20   6.3   3.4 | -27.1 -16.8  295  28 15   6.9   3.8
 27000 -24.8 -12.6  285  36 19   6.2   3.4 | -24.5 -12.1  295  27 14   6.9   3.8
 26000 -22.9  -9.2  285  35 18   6.2   3.4 | -22.4  -8.3  290  27 14   6.9   3.8
 25000 -21.1  -6.0  280  34 17   6.4   3.5 | -20.4  -4.7  290  26 13   6.9   3.8
 24000 -19.0  -2.2  280  30 16   7.0   3.8 | -18.3  -0.9  290  26 13   6.9   3.8
 23000 -17.0   1.4  280  27 14   7.1   3.9 | -16.3   2.7  285  26 13   6.9   3.8
 22000 -14.9   5.2  280  23 12   8.0   4.4 | -14.2   6.4  285  26 13   7.5   4.1
 21000 -12.2  10.0  280  22 11   9.1   5.0 | -11.8  10.8  280  24 12   8.4   4.6
 20000  -9.5  14.9  280  21 11   9.1   5.0 |  -9.4  15.1  280  23 12   8.5   4.7
 19500  -8.1  17.4  280  21 11   9.1   5.0 |  -8.1  17.4  275  22 11   8.5   4.7
 19000  -6.7  19.9  280  21 11   9.8   5.4 |  -6.8  19.8  275  22 11   9.7   5.3
 18500  -5.3  22.5  280  21 11   9.7   5.3 |  -5.4  22.3  275  22 11   9.6   5.3
 18000  -3.9  25.0  275  20 10   9.7   5.3 |  -3.9  25.0  275  22 11   9.7   5.3
 17500  -2.4  27.7  275  20 10   9.6   5.3 |  -2.5  27.5  275  22 12   9.7   5.3
 17000  -1.0  30.2  275  20 10   9.6   5.3 |  -1.0  30.2  275  23 12   9.8   5.4
 16500   0.4  32.7  275  20 11   9.7   5.3 |   0.4  32.7  275  23 12   9.6   5.2
 16000   1.9  35.4  275  21 11   9.7   5.3 |   1.9  35.4  275  23 12   9.6   5.3
 15500   3.3  37.9  275  21 11   9.6   5.3 |   3.3  37.9  275  23 12   9.3   5.1
 15000   4.7  40.5  275  21 11   9.6   5.3 |   4.6  40.3  275  22 11   9.3   5.1
 14500   6.2  43.2  275  21 11   9.5   5.2 |   6.0  42.8  280  22 11   9.2   5.1
 14000   7.5  45.5  275  21 11   9.3   5.1 |   7.3  45.1  280  21 11   9.1   5.0
 13500   8.9  48.0  275  20 11   9.3   5.1 |   8.7  47.7  280  20 10   9.1   5.0
 13000  10.9  51.6  275  20 10   8.9   4.9 |  10.6  51.1  280  19 10   8.9   4.9
 12500  12.1  53.8  275  19 10   8.7   4.8 |  11.9  53.4  285  18  9   9.0   5.0
 12000  13.4  56.1  275  18  9   8.4   4.6 |  13.2  55.8  280  17  9   9.2   5.0
 11500  14.6  58.3  275  17  9   7.9   4.4 |  14.6  58.3  280  16  8   8.8   4.8
 11000  15.5  59.9  275  15  8   6.1   3.4 |  15.7  60.3  280  16  8   7.6   4.2
 10500  16.4  61.5  280  13  7   8.9   4.9 |  16.8  62.2  275  15  8  10.0   5.5
 10250  17.2  63.0  280  12  6   8.5   4.7 |  17.6  63.7  275  14  7  10.3   5.6
 10000  17.6  63.7  280  10  5   4.7   2.6 |  18.2  64.8  275  14  7   7.1   3.9
  9750  18.0  64.4  275   9  5   5.8   3.2 |  18.7  65.7  275  13  7   8.2   4.5
  9500  18.4  65.1  275   7  4   5.1   2.8 |  19.3  66.7  270  12  6   7.1   3.9
  9250  18.8  65.8  275   6  3   5.6   3.1 |  19.8  67.6  270  11  6   6.1   3.4
  9000  19.2  66.6  275   5  3   6.3   3.5 |  20.2  68.4  270  10  5   6.3   3.5
  8750  19.7  67.5  275   4  2   6.3   3.5 |  20.7  69.3  265   9  5   6.0   3.3
  8500  20.1  68.2  275   3  1   5.9   3.3 |  21.2  70.2  265   8  4   7.1   3.9
  8250  20.5  68.9  270   2  1   4.9   2.7 |  21.8  71.2  265   8  4   9.0   4.9
  8000  20.8  69.4  260   1  1   3.9   2.1 |  22.4  72.3  260   7  4   8.8   4.8
  7750  21.1  70.0  230   1  0   3.4   1.8 |  23.0  73.4  260   7  4   8.1   4.4
  7500  21.4  70.5  190   1  1   3.8   2.1 |  23.6  74.5  260   7  3   9.4   5.2
  7250  21.7  71.1  170   2  1   4.4   2.4 |  24.4  75.9  260   6  3  11.3   6.2
  7000  22.0  71.6  155   2  1   4.1   2.3 |  25.2  77.4  260   6  3  10.4   5.7
  6750  22.2  72.0  145   2  1   3.3   1.8 |  26.0  78.8  260   6  3   9.3   5.1
  6500  22.5  72.5  140   3  1   6.4   3.5 |  26.7  80.1  260   6  3  10.8   5.9
  6250  23.1  73.6  135   3  1   9.2   5.1 |  27.6  81.7  260   6  3  12.3   6.7
  6000  23.7  74.7  130   3  1   8.0   4.4 |  28.4  83.1  260   6  3  11.0   6.0
  5750  24.3  75.7  130   2  1   8.7   4.8 |  29.2  84.6  260   6  3  11.6   6.3
  5500  25.0  77.0  125   2  1  10.9   6.0 |  30.3  86.5  260   6  3  16.0   8.8
  5250  25.9  78.6  125   2  1  12.1   6.6 |  31.6  88.9  260   6  3  19.2  10.5
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           06/22/2017 at 1500 MDT          |       06/22/2017 at 1800 MDT
                                           |
K index... +12.4  LI... +0.3               | K index... +21.8  LI... +0.1
CAPE... +56.5  CIN... -14.0                | CAPE... +129.6  CIN... -166.3
                                           |
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 -64.6 -84.3  265  34 17   2.1   1.2 | -63.7 -82.7  270  41 21   2.1   1.1
 45000 -59.4 -74.9  265  50 26   6.5   3.6 | -59.1 -74.4  275  56 29   5.5   3.0
 40000 -49.6 -57.3  275  56 29   4.4   2.4 | -50.6 -59.1  280  55 28   4.2   2.3
 38000 -47.0 -52.6  280  50 26   4.4   2.4 | -48.1 -54.6  280  42 21   4.2   2.3
 36000 -44.4 -47.9  285  43 22   4.2   2.3 | -45.6 -50.1  280  28 14   3.8   2.1
 34000 -40.3 -40.5  290  36 19   7.1   3.9 | -40.9 -41.6  280  26 13   8.3   4.6
 32000 -36.0 -32.8  300  29 15   7.0   3.8 | -35.9 -32.6  280  26 13   8.2   4.5
 30000 -31.6 -24.9  300  24 12   7.5   4.1 | -31.3 -24.3  285  28 14   7.6   4.2
 29000 -29.3 -20.7  305  22 11   7.5   4.1 | -29.1 -20.4  285  29 15   7.6   4.2
 28000 -27.1 -16.8  305  20 10   7.6   4.2 | -26.8 -16.2  290  31 16   7.1   3.9
 27000 -24.2 -11.6  300  20 10   7.7   4.2 | -24.4 -11.9  290  31 16   6.4   3.5
 26000 -21.9  -7.4  300  20 10   7.7   4.2 | -22.5  -8.5  290  32 17   6.4   3.5
 25000 -19.7  -3.5  295  20 10   7.5   4.1 | -20.6  -5.1  295  33 17   6.9   3.8
 24000 -17.5   0.5  295  19 10   7.2   4.0 | -18.4  -1.1  290  33 17   7.6   4.2
 23000 -15.4   4.3  290  19 10   7.2   4.0 | -16.1   3.0  290  33 17   7.6   4.2
 22000 -13.2   8.2  285  18  9   7.5   4.1 | -13.9   7.0  290  33 17   8.2   4.5
 21000 -10.9  12.4  285  17  9   7.8   4.3 | -11.3  11.7  290  32 17   8.7   4.8
 20000  -8.6  16.5  285  17  9   7.8   4.3 |  -8.8  16.2  290  32 16   8.8   4.8
 19500  -7.5  18.5  285  16  8   7.8   4.3 |  -7.5  18.5  295  31 16   8.8   4.8
 19000  -6.2  20.8  280  16  8   8.8   4.8 |  -6.2  20.8  295  31 16   9.0   5.0
 18500  -5.0  23.0  280  16  8   8.8   4.8 |  -4.9  23.2  295  30 16   9.0   4.9
 18000  -3.7  25.3  280  15  8   9.0   4.9 |  -3.6  25.5  295  30 15   8.7   4.8
 17500  -2.3  27.9  275  15  8   9.2   5.0 |  -2.3  27.9  295  29 15   8.4   4.6
 17000  -0.9  30.4  275  16  8   9.2   5.1 |  -1.1  30.0  295  28 15   8.3   4.6
 16500   0.4  32.7  275  16  8   9.3   5.1 |   0.2  32.4  300  28 14   9.3   5.1
 16000   1.8  35.2  275  16  8   9.3   5.1 |   1.6  34.9  300  27 14   9.2   5.1
 15500   3.2  37.8  275  16  8   9.3   5.1 |   2.9  37.2  300  27 14   9.1   5.0
 15000   4.6  40.3  275  16  8   9.3   5.1 |   4.3  39.7  300  26 14   9.1   5.0
 14500   6.0  42.8  275  17  8   9.2   5.0 |   5.7  42.3  300  26 13   9.1   5.0
 14000   7.3  45.1  275  17  9   9.0   4.9 |   7.0  44.6  305  25 13   9.1   5.0
 13500   8.6  47.5  275  17  9   9.0   4.9 |   8.4  47.1  305  24 13   9.1   5.0
 13000  10.7  51.3  275  17  9   9.3   5.1 |  10.4  50.7  305  23 12   9.1   5.0
 12500  12.1  53.8  275  17  9   9.3   5.1 |  11.7  53.1  305  22 12   9.0   4.9
 12000  13.4  56.1  275  17  9   9.2   5.0 |  13.0  55.4  310  21 11   8.8   4.8
 11500  14.8  58.6  275  17  9   8.9   4.9 |  14.3  57.7  310  20 10   8.4   4.6
 11000  16.0  60.8  275  17  9   8.0   4.4 |  15.4  59.7  310  19 10   7.2   4.0
 10500  17.1  62.8  275  17  9  11.3   6.2 |  16.5  61.7  315  17  9   9.6   5.3
 10250  18.1  64.6  275  17  9  11.7   6.4 |  17.3  63.1  315  17  9  10.5   5.7
 10000  18.8  65.8  275  16  8   8.7   4.8 |  17.9  64.2  315  16  8   7.7   4.2
  9750  19.4  66.9  275  16  8   9.5   5.2 |  18.5  65.3  320  15  8   8.8   4.8
  9500  20.1  68.2  275  16  8   9.5   5.2 |  19.1  66.4  320  15  8   7.2   4.0
  9250  20.8  69.4  275  16  8  10.0   5.5 |  19.6  67.3  320  14  7   6.8   3.7
  9000  21.5  70.7  275  16  8  10.1   5.5 |  20.2  68.4  325  13  7   7.9   4.3
  8750  22.3  72.1  275  16  8   9.9   5.4 |  20.7  69.3  325  12  6   7.4   4.1
  8500  23.0  73.4  275  16  8  10.5   5.8 |  21.3  70.3  330  11  6   8.1   4.4
  8250  23.8  74.8  275  16  8  10.8   5.9 |  21.9  71.4  335  10  5   8.7   4.8
  8000  24.6  76.3  275  15  8   9.6   5.3 |  22.5  72.5  340   9  5   7.5   4.1
  7750  25.3  77.5  275  15  8   8.9   4.9 |  23.0  73.4  345   9  4   6.5   3.6
  7500  25.9  78.6  275  15  8   9.9   5.4 |  23.5  74.3  355   8  4   7.4   4.1
  7250  26.8  80.2  275  15  8  11.7   6.4 |  24.1  75.4  005   8  4   8.7   4.8
  7000  27.6  81.7  275  15  8  10.2   5.6 |  24.7  76.5  015   7  4   7.7   4.2
  6750  28.3  82.9  275  15  8   8.0   4.4 |  25.2  77.4  030   8  4   6.8   3.7
  6500  29.0  84.2  275  15  8  10.6   5.8 |  25.7  78.3  045   8  4   5.6   3.1
  6250  29.9  85.8  275  15  8  13.0   7.1 |  25.9  78.6  050   8  4   4.3   2.3
  6000  30.8  87.4  275  14  7  11.6   6.4 |  26.2  79.2  060   9  5   4.7   2.6
  5750  31.6  88.9  275  14  7  11.6   6.4 |  26.5  79.7  065   9  4   4.7   2.6
  5500  32.6  90.7  275  14  7  15.9   8.7 |  26.9  80.4  070   8  4   5.2   2.8
  5250  34.0  93.2  275  13  7  20.7  11.4 |  27.2  81.0  070   8  4   5.3   2.9
  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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