Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 281236
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0636 MDT Wednesday, June 28, 2017

This forecast is for Wednesday, June 28, 2017:

If the trigger temperature of 84.9 F/29.4 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 1679 ft/min (8.5 m/s)
   Maximum height of thermals.................. 22201 ft MSL (17362 ft AGL)

Forecast maximum temperature................... 97.0 F/36.6 C
Time of trigger temperature.................... 1015 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 18445 ft MSL (13606 ft AGL)
Thermal soaring outlook for Thursday 06/29..... Excellent

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

Remarks...

Sunrise/Sunset.................... 05:50:49 / 20:44:08 MDT
Total possible sunshine........... 14 hr 53 min 19 sec (893 min 19 sec)
Altitude of sun at 13:17:32 MDT... 74.09 degrees

Upper air data from rawinsonde observation taken on 06/28/2017 at 0600 MDT

Freezing level.................. 15468 ft MSL (10629 ft AGL)
Convective condensation level... 19303 ft MSL (14464 ft AGL)
Lifted condensation level....... 20679 ft MSL (15840 ft AGL)
Lifted index.................... -0.8
K index......................... +11.7

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  -64.4 -83.9   275   39   20   1.3   0.7   87.0 188.5    29.5      M    M
 45000  -58.3 -72.9   275   60   31   5.5   3.0   72.7 162.9    22.8      M    M
 40000  -50.9 -59.6   285   80   41   2.9   1.6   61.4 142.5    16.8      M    M
 38000  -48.4 -55.1   285   73   38  -0.8  -0.4   56.4 133.5    13.9      M    M
 36000  -46.1 -51.0   280   65   33   8.3   4.5   50.1 122.2     9.9      M    M
 34000  -40.8 -41.4   275   56   29   7.3   4.0   49.3 120.8     9.5      M    M
 32000  -38.1 -36.6   270   47   24   8.9   4.9   45.0 112.9     6.5      M    M
 30000  -32.8 -27.0   265   48   25   8.8   4.8   44.3 111.7     6.2      M    M
 29000  -30.2 -22.4   265   48   25   8.7   4.8   43.9 111.0     6.0      M    M
 28000  -27.9 -18.2   265   47   24   7.2   4.0   43.0 109.3     5.3      M    M
 27000  -25.7 -14.3   270   47   24   7.2   4.0   42.0 107.6     4.6      M    M
 26000  -23.6 -10.5   270   47   24   7.2   4.0   41.2 106.2     4.0      M    M
 25000  -21.4  -6.5   270   39   20   7.2   4.0   40.2 104.4     3.3      M    M
 24000  -19.3  -2.7   270   36   19   7.0   3.8   39.2 102.6     2.5      M    M
 23000  -17.2   1.0   265   33   17   6.9   3.8   38.2 100.8     1.7      M    M
 22000  -16.3   2.7   260   30   15   0.5   0.3   35.8  96.4    -0.3   1675  8.5
 21000  -15.4   4.3   250   27   14   9.7   5.3   33.5  92.2    -2.5   1620  8.2
 20000  -12.6   9.3   235   25   13   9.1   5.0   33.4  92.1    -2.6   1506  7.7
 19500  -11.3  11.7   240   24   13   9.1   5.0   33.3  91.9    -2.7   1450  7.4
 19000   -9.2  15.4   245   24   12   9.4   5.1   33.2  91.7    -2.9   1366  6.9
 18500   -7.9  17.8   245   24   12   9.1   5.0   33.0  91.4    -3.0   1312  6.7
 18000   -6.5  20.3   250   24   12   9.3   5.1   32.9  91.3    -3.2   1257  6.4
 17500   -5.2  22.6   250   23   12   8.8   4.8   32.8  91.0    -3.3   1202  6.1
 17000   -3.9  25.0   250   23   12   8.8   4.8   32.7  90.8    -3.4   1148  5.8
 16500   -2.6  27.3   255   23   12   8.8   4.8   32.6  90.6    -3.6   1093  5.6
 16000   -1.2  29.8   255   23   12   8.8   4.8   32.5  90.4    -3.7   1039  5.3
 15500    0.1  32.2   255   21   11   8.8   4.8   32.3  90.2    -3.8    984  5.0
 15000    1.4  34.5   255   20   10   8.8   4.8   32.2  89.9    -3.9    929  4.7
 14500    2.7  36.9   250   20   10   8.8   4.8   32.0  89.6    -4.1    875  4.4
 14000    4.1  39.4   245   20   10   8.8   4.8   31.9  89.4    -4.3    820  4.2
 13500    5.4  41.7   240   16    8   8.8   4.8   31.7  89.1    -4.4    766  3.9
 13000    6.7  44.1   235   13    7   8.8   4.8   31.5  88.8    -4.6    711  3.6
 12500    8.0  46.4   250   10    5   8.8   4.8   31.3  88.4    -4.8    657  3.3
 12000    9.4  48.9   270    8    4   8.8   4.8   31.2  88.1    -5.0    602  3.1
 11500   10.7  51.3   270    7    3   8.7   4.8   31.0  87.8    -5.2    548  2.8
 11000   11.9  53.4   275    5    3   8.3   4.6   30.7  87.3    -5.5    496  2.5
 10500   13.1  55.6   280    4    2   8.3   4.6   30.5  87.0    -5.8    446  2.3
 10250   13.7  56.7   285    3    2   8.6   4.7   30.4  86.8    -5.9    421  2.1
 10000   14.3  57.7   290    2    1   8.9   4.9   30.4  86.6    -6.0    394  2.0
  9750   15.0  59.0   295    2    1   8.8   4.9   30.3  86.5    -6.1    367  1.9
  9500   15.6  60.1   310    1    1   8.8   4.9   30.2  86.4    -6.2    340  1.7
  9250   16.3  61.3   340    1    0   8.9   4.9   30.1  86.3    -6.3    313  1.6
  9000   17.0  62.6   020    1    0   8.8   4.8   30.1  86.2    -6.4    286  1.5
  8750   17.6  63.7   060    2    1   8.9   4.9   30.0  86.0    -6.5    259  1.3
  8500   18.3  64.9   070    4    2   8.5   4.7   29.9  85.9    -6.6    232  1.2
  8250   18.9  66.0   075    5    3  10.1   5.5   29.9  85.8    -6.7    205  1.0
  8000   19.6  67.3   075    7    3   4.3   2.4   29.8  85.6    -6.8    178  0.9
  7750   19.6  67.3   075    8    4   0.0   0.0   29.1  84.3    -7.5    170  0.9
  7500   19.8  67.6   070    9    5   5.7   3.1   28.6  83.4    -8.0    155  0.8
  7250   20.3  68.5   070   10    5   7.2   3.9   28.3  83.0    -8.2    133  0.7
  7000   20.9  69.6   070   12    6   6.8   3.7   28.1  82.6    -8.5    110  0.6
  6750   21.4  70.5   075   11    6   6.9   3.8   27.9  82.2    -8.7     87  0.4
  6500   21.9  71.4   085   11    6   6.9   3.8   27.7  81.8    -9.0     64  0.3
  6250   22.4  72.3   095   11    6   6.9   3.8   27.5  81.4    -9.2     42  0.2
  6000   22.9  73.2   100   11    6   6.9   3.8   27.2  81.0    -9.4     19  0.1
  5750   23.4  74.1   105   10    5   6.7   3.7   27.0  80.6    -9.7      M    M
  5500   23.9  75.0   100   10    5   7.6   4.1   26.8  80.2    -9.9      M    M
  5250   24.4  75.9   100    9    4   4.3   2.4   26.6  79.9   -10.2      M    M
  5000   24.0  75.2   100    8    4 -16.9  -9.3   25.5  78.0   -11.3      M    M

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

           06/28/2017 at 0900 MDT          |       06/28/2017 at 1200 MDT
                                           |
K index... +12.8  LI... +0.7               | K index... +8.4  LI... +0.1
CAPE... 0.0  CIN... -0.6                   | CAPE... +2.8  CIN... -10.4
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -63.6 -82.5  275  43 22   2.9   1.6 | -63.5 -82.3  270  43 22   2.7   1.5
 45000 -58.2 -72.8  280  64 33   5.6   3.1 | -58.2 -72.8  275  65 34   6.0   3.3
 40000 -49.5 -57.1  280  76 39   3.8   2.1 | -49.1 -56.4  275  78 40   3.9   2.1
 38000 -47.2 -53.0  280  75 38   3.9   2.1 | -46.7 -52.1  280  77 40   4.0   2.2
 36000 -44.8 -48.6  285  73 38   4.0   2.2 | -44.3 -47.7  280  77 40   4.0   2.2
 34000 -41.5 -42.7  280  66 34   6.0   3.3 | -41.2 -42.2  280  72 37   5.6   3.1
 32000 -37.9 -36.2  280  57 29   6.1   3.3 | -37.8 -36.0  280  64 33   5.7   3.1
 30000 -33.2 -27.8  275  52 27   8.7   4.8 | -33.3 -27.9  275  58 30   8.5   4.6
 29000 -30.6 -23.1  275  51 26   8.7   4.8 | -30.2 -22.4  275  55 29   8.5   4.6
 28000 -27.3 -17.1  275  49 25   8.1   4.5 | -27.6 -17.7  275  53 27   8.1   4.4
 27000 -25.2 -13.4  275  47 24   7.1   3.9 | -25.4 -13.7  275  49 25   7.3   4.0
 26000 -23.1  -9.6  275  45 23   7.1   3.9 | -23.2  -9.8  275  44 23   7.3   4.0
 25000 -20.9  -5.6  275  42 22   7.3   4.0 | -21.0  -5.8  275  40 20   7.6   4.1
 24000 -19.2  -2.6  270  39 20   5.4   3.0 | -19.3  -2.7  270  37 19   5.0   2.8
 23000 -17.6   0.3  270  34 18   5.4   3.0 | -17.8  -0.0  270  35 18   5.1   2.8
 22000 -16.0   3.2  270  30 16   5.3   2.9 | -16.3   2.7  270  33 17   4.9   2.7
 21000 -14.1   6.6  260  28 15   6.7   3.7 | -14.4   6.1  265  31 16   7.1   3.9
 20000 -12.2  10.0  255  27 14   6.9   3.8 | -12.3   9.9  255  29 15   7.2   3.9
 19500 -11.2  11.8  250  27 14   7.0   3.8 | -11.3  11.7  255  29 15   7.2   4.0
 19000 -10.2  13.6  250  27 14   8.7   4.8 | -10.2  13.6  250  28 14   8.7   4.8
 18500  -8.8  16.2  250  26 13   9.3   5.1 |  -8.8  16.2  250  27 14   9.2   5.0
 18000  -7.4  18.7  250  24 13   9.3   5.1 |  -7.4  18.7  250  26 13   9.2   5.0
 17500  -6.1  21.0  255  24 12   9.2   5.0 |  -6.0  21.2  250  25 13   9.0   5.0
 17000  -4.7  23.5  255  23 12   9.2   5.0 |  -4.7  23.5  255  24 12   9.0   5.0
 16500  -3.3  26.1  260  22 11   9.2   5.1 |  -3.3  26.1  255  23 12   9.4   5.1
 16000  -2.0  28.4  260  22 11   9.2   5.1 |  -1.9  28.6  255  23 12   9.4   5.2
 15500  -0.6  30.9  265  22 11   9.3   5.1 |  -0.5  31.1  260  22 11   9.3   5.1
 15000   0.8  33.4  265  21 11   9.3   5.1 |   0.9  33.6  260  22 11   9.0   4.9
 14500   2.1  35.8  265  20 10   9.3   5.1 |   2.2  36.0  260  21 11   9.0   4.9
 14000   3.5  38.3  265  19 10   9.1   5.0 |   4.2  39.6  260  21 11   9.1   5.0
 13500   5.5  41.9  265  17  9   9.0   5.0 |   5.5  41.9  260  20 10   9.2   5.0
 13000   6.8  44.2  265  15  8   8.9   4.9 |   6.8  44.2  260  20 10   9.2   5.1
 12500   8.2  46.8  265  13  7   8.8   4.8 |   8.1  46.6  260  19 10   9.2   5.0
 12000   9.4  48.9  265  11  6   8.0   4.4 |   9.4  48.9  260  18  9   8.8   4.8
 11500  10.6  51.1  260   9  5   8.1   4.4 |  10.7  51.3  260  16  8   8.8   4.8
 11000  11.7  53.1  260   7  4   6.5   3.6 |  11.9  53.4  255  14  7   7.9   4.3
 10500  12.7  54.9  255   6  3   8.9   4.9 |  13.1  55.6  255  12  6   9.7   5.3
 10250  13.6  56.5  255   5  3   9.8   5.4 |  14.0  57.2  255  11  6   9.7   5.3
 10000  14.2  57.6  245   5  3   7.4   4.0 |  14.5  58.1  250  10  5   7.2   4.0
  9750  14.8  58.6  240   5  3   7.9   4.4 |  15.1  59.2  250   9  5   8.0   4.4
  9500  15.4  59.7  235   5  3   8.2   4.5 |  15.7  60.3  250   9  4   7.3   4.0
  9250  16.0  60.8  230   5  2   8.3   4.5 |  16.3  61.3  245   8  4   7.2   3.9
  9000  16.5  61.7  220   5  2   7.4   4.0 |  16.8  62.2  245   7  4   7.8   4.3
  8750  17.0  62.6  215   5  2   7.2   3.9 |  17.4  63.3  245   7  4   7.7   4.2
  8500  17.5  63.5  205   5  2   7.2   3.9 |  18.0  64.4  245   7  3   8.1   4.5
  8250  18.0  64.4  200   5  2   6.4   3.5 |  18.6  65.5  245   6  3   9.6   5.3
  8000  18.4  65.1  190   5  3   4.7   2.6 |  19.3  66.7  245   6  3   9.7   5.3
  7750  18.7  65.7  185   5  3   4.0   2.2 |  20.0  68.0  245   6  3   8.9   4.9
  7500  19.1  66.4  180   6  3   3.9   2.2 |  20.7  69.3  245   6  3   9.6   5.2
  7250  19.4  66.9  175   6  3   3.4   1.8 |  21.4  70.5  245   6  3  10.3   5.6
  7000  19.7  67.5  175   6  3   3.1   1.7 |  22.2  72.0  245   6  3  10.6   5.8
  6750  19.9  67.8  170   6  3   1.8   1.0 |  23.0  73.4  245   6  3  10.6   5.8
  6500  20.1  68.2  165   6  3   4.6   2.5 |  23.8  74.8  245   6  3  11.2   6.1
  6250  20.5  68.9  165   5  3   7.3   4.0 |  24.7  76.5  245   6  3  12.1   6.6
  6000  21.0  69.8  165   4  2   7.3   4.0 |  25.5  77.9  245   6  3  10.9   6.0
  5750  21.7  71.1  165   4  2   9.9   5.5 |  26.4  79.5  245   6  3  10.9   6.0
  5500  22.5  72.5  165   4  2  11.6   6.4 |  27.3  81.1  250   6  3  15.6   8.5
  5250  23.3  73.9  165   3  2  11.5   6.3 |  28.7  83.7  250   6  3  20.3  11.1
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           06/28/2017 at 1500 MDT          |       06/28/2017 at 1800 MDT
                                           |
K index... +8.4  LI... +1.0                | K index... +5.6  LI... +0.7
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 -63.9 -83.0  265  44 23   2.7   1.5 | -63.7 -82.7  270  50 26   2.2   1.2
 45000 -58.6 -73.5  275  67 34   6.1   3.3 | -59.0 -74.2  280  71 37   5.9   3.2
 40000 -49.2 -56.6  280  83 43   4.1   2.2 | -49.9 -57.8  280  83 43   4.3   2.4
 38000 -46.7 -52.1  280  82 42   4.1   2.3 | -47.3 -53.1  280  83 43   4.4   2.4
 36000 -44.2 -47.6  280  82 42   4.2   2.3 | -44.7 -48.5  280  83 43   4.4   2.4
 34000 -41.0 -41.8  280  75 39   5.8   3.2 | -41.4 -42.5  280  78 40   5.8   3.2
 32000 -37.6 -35.7  275  66 34   5.8   3.2 | -37.9 -36.2  280  72 37   5.9   3.2
 30000 -33.2 -27.8  275  59 31   7.9   4.4 | -33.7 -28.7  275  65 34   7.6   4.2
 29000 -30.3 -22.5  275  57 29   7.9   4.4 | -31.5 -24.7  275  62 32   7.6   4.2
 28000 -27.9 -18.2  275  54 28   7.6   4.1 | -28.6 -19.5  275  58 30   7.3   4.0
 27000 -25.8 -14.4  270  51 26   6.9   3.8 | -26.5 -15.7  275  54 28   7.0   3.8
 26000 -23.7 -10.7  270  47 24   6.9   3.8 | -24.5 -12.1  270  49 25   7.0   3.8
 25000 -21.7  -7.1  270  44 23   7.0   3.8 | -22.4  -8.3  270  45 23   7.0   3.8
 24000 -19.7  -3.5  265  41 21   6.3   3.5 | -20.3  -4.5  265  41 21   7.0   3.8
 23000 -17.8  -0.0  265  39 20   6.3   3.5 | -18.2  -0.8  265  38 20   7.0   3.9
 22000 -15.9   3.4  260  36 19   6.3   3.4 | -16.1   3.0  260  35 18   7.1   3.9
 21000 -13.8   7.2  260  34 18   7.4   4.1 | -13.7   7.3  255  33 17   8.6   4.7
 20000 -11.6  11.1  255  33 17   7.5   4.1 | -11.1  12.0  255  32 17   8.7   4.8
 19500 -10.6  12.9  250  32 16   7.5   4.1 |  -9.8  14.4  250  32 16   8.6   4.7
 19000  -9.4  15.1  250  31 16   8.7   4.8 |  -8.5  16.7  250  31 16   9.3   5.1
 18500  -8.1  17.4  250  30 16   9.0   4.9 |  -7.1  19.2  250  30 16   9.5   5.2
 18000  -6.8  19.8  245  30 15   9.1   5.0 |  -5.7  21.7  250  30 15   9.5   5.2
 17500  -5.4  22.3  245  29 15   9.4   5.2 |  -4.3  24.3  250  29 15   9.2   5.0
 17000  -4.0  24.8  245  28 15   9.4   5.1 |  -3.0  26.6  250  29 15   9.2   5.0
 16500  -2.6  27.3  245  28 14   9.4   5.2 |  -1.6  29.1  250  29 15   9.4   5.2
 16000  -1.2  29.8  245  27 14   9.4   5.2 |  -0.2  31.6  250  28 15   9.4   5.2
 15500   0.2  32.4  250  27 14   9.3   5.1 |   1.2  34.2  250  28 14   9.4   5.1
 15000   1.6  34.9  250  26 14   9.1   5.0 |   2.6  36.7  250  27 14   9.3   5.1
 14500   2.9  37.2  250  26 13   9.1   5.0 |   4.0  39.2  250  27 14   9.3   5.1
 14000   4.9  40.8  250  25 13   9.1   5.0 |   5.4  41.7  250  27 14   9.3   5.1
 13500   6.3  43.3  255  25 13   9.1   5.0 |   7.5  45.5  255  26 13   9.3   5.1
 13000   7.7  45.9  255  24 12   9.1   5.0 |   8.9  48.0  255  26 13   9.3   5.1
 12500   9.0  48.2  255  23 12   9.1   5.0 |  10.2  50.4  255  25 13   9.3   5.1
 12000  10.4  50.7  255  22 12   9.0   4.9 |  11.6  52.9  255  24 12   8.9   4.9
 11500  11.7  53.1  260  22 11   9.0   4.9 |  12.9  55.2  255  23 12   8.9   4.9
 11000  13.0  55.4  260  20 10   8.4   4.6 |  14.2  57.6  255  22 12   8.1   4.4
 10500  14.2  57.6  260  17  9  10.2   5.6 |  15.4  59.7  260  21 11   9.5   5.2
 10250  15.1  59.2  265  17  9  10.8   5.9 |  16.2  61.2  260  21 11  10.2   5.6
 10000  15.8  60.4  265  16  8   8.9   4.9 |  16.9  62.4  260  20 10   8.8   4.8
  9750  16.4  61.5  265  15  8   9.5   5.2 |  17.5  63.5  260  18 10   9.3   5.1
  9500  17.1  62.8  265  15  8   9.1   5.0 |  18.2  64.8  260  17  9   8.7   4.8
  9250  17.8  64.0  265  14  7   9.5   5.2 |  18.9  66.0  260  16  8   8.9   4.9
  9000  18.5  65.3  265  14  7  10.0   5.5 |  19.6  67.3  265  16  8   9.6   5.3
  8750  19.3  66.7  265  14  7   9.9   5.4 |  20.3  68.5  265  15  8   9.4   5.2
  8500  20.0  68.0  265  14  7  10.0   5.5 |  21.0  69.8  265  15  8   9.7   5.3
  8250  20.8  69.4  265  14  7  10.3   5.7 |  21.7  71.1  265  14  7  11.3   6.2
  8000  21.5  70.7  265  14  7  10.0   5.5 |  22.6  72.7  265  14  7  10.3   5.7
  7750  22.3  72.1  265  14  7   9.6   5.3 |  23.2  73.8  265  14  7   8.7   4.8
  7500  23.0  73.4  265  13  7  10.0   5.5 |  23.9  75.0  265  14  7   9.3   5.1
  7250  23.7  74.7  265  13  7  10.9   6.0 |  24.6  76.3  265  13  7  10.0   5.5
  7000  24.6  76.3  265  13  7  10.5   5.8 |  25.4  77.7  265  13  7  10.1   5.5
  6750  25.3  77.5  265  13  7   9.3   5.1 |  26.1  79.0  270  13  7   9.5   5.2
  6500  26.0  78.8  265  13  7  10.7   5.9 |  26.8  80.2  270  13  7  10.3   5.7
  6250  26.9  80.4  265  12  6  12.5   6.9 |  27.7  81.9  270  12  6  11.6   6.4
  6000  27.8  82.0  265  12  6  11.7   6.4 |  28.6  83.5  270  12  6  11.4   6.3
  5750  28.7  83.7  265  12  6  10.9   6.0 |  29.4  84.9  270  12  6  10.5   5.7
  5500  29.6  85.3  265  11  6  15.3   8.4 |  30.1  86.2  270  11  6  10.8   5.9
  5250  31.0  87.8  265  11  6  22.5  12.3 |  31.0  87.8  270  11  6  12.2   6.7
  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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