Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 201256
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0656 MDT Sunday, May 20, 2018

This forecast is for Sunday, May 20, 2018:

If the trigger temperature of 68.0 F/20.0 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 503 ft/min (2.6 m/s)
   Maximum height of thermals.................. 13700 ft MSL (8861 ft AGL)

Forecast maximum temperature................... 77.0 F/25.5 C
Time of trigger temperature.................... 0945 MDT
Time of overdevelopment........................ 1500 MDT
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................. 9578 ft MSL (4738 ft AGL)
Thermal soaring outlook for Monday 05/21....... Good

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

Remarks...

Sunrise/Sunset.................... 05:57:06 / 20:24:06 MDT
Total possible sunshine........... 14 hr 27 min 1 sec (867 min 1 sec)
Altitude of sun at 13:10:47 MDT... 70.96 degrees

Upper air data from rawinsonde observation taken on 05/20/2018 at 0600 MDT

Freezing level.................. 13027 ft MSL (8188 ft AGL)
Convective condensation level... 15495 ft MSL (10656 ft AGL)
Lifted condensation level....... 15135 ft MSL (10296 ft AGL)
Lifted index.................... -1.0
K index......................... +16.1

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  -56.4 -69.5   205   12    6   2.4   1.3  106.3 223.4    46.5      M    M
 45000  -57.1 -70.8   215   33   17  -3.0  -1.7   79.1 174.4    33.2      M    M
 40000  -61.7 -79.1   185   21   11   4.7   2.6   48.9 120.0    15.7      M    M
 38000  -59.3 -74.7   190   25   13   4.3   2.3   43.8 110.8    12.7      M    M
 36000  -55.2 -67.4   195   19   10   8.7   4.8   41.0 105.9    11.1      M    M
 34000  -50.7 -59.3   195   14    7   6.9   3.8   39.2 102.6    10.1      M    M
 32000  -45.5 -49.9   205   10    5   7.8   4.3   37.5  99.4     9.1      M    M
 30000  -40.6 -41.1   225    8    4   8.6   4.7   36.3  97.3     8.5      M    M
 29000  -38.0 -36.4   240    5    3   8.6   4.7   35.9  96.6     8.3      M    M
 28000  -35.4 -31.7   240    9    4   8.6   4.7   35.4  95.7     8.0      M    M
 27000  -32.9 -27.2   240   12    6   8.6   4.7   35.0  95.0     7.8      M    M
 26000  -30.3 -22.5   245   14    7   8.6   4.7   34.4  93.9     7.4      M    M
 25000  -27.7 -17.9   245   17    9   8.6   4.7   34.0  93.1     7.2      M    M
 24000  -25.1 -13.2   240   19   10   9.3   5.1   33.5  92.3     6.9      M    M
 23000  -23.3  -9.9   255   11    6   4.2   2.3   32.1  89.8     5.8      M    M
 22000  -22.4  -8.3   240   12    6   9.5   5.2   29.8  85.6     3.9      M    M
 21000  -19.6  -3.3   225   15    8   9.1   5.0   29.5  85.2     3.8      M    M
 20000  -16.9   1.6   230   19   10   8.1   4.5   29.3  84.7     3.6      M    M
 19500  -16.2   2.8   235   20   10   4.1   2.3   28.6  83.5     2.9      M    M
 19000  -15.1   4.8   240   21   11  10.3   5.6   28.1  82.6     2.5      M    M
 18500  -13.8   7.2   240   22   11   8.4   4.6   28.0  82.4     2.4      M    M
 18000  -11.9  10.6   240   23   12   7.8   4.3   27.7  81.8     2.1      M    M
 17500  -10.7  12.7   235   21   11   9.2   5.1   27.4  81.2     1.9      M    M
 17000   -9.2  15.4   235   19   10   8.7   4.8   27.3  81.1     1.8      M    M
 16500   -8.0  17.6   240   18    9   8.1   4.5   27.0  80.6     1.6      M    M
 16000   -6.8  19.8   245   17    9   8.1   4.5   26.7  80.1     1.3      M    M
 15500   -5.6  21.9   250   16    8   8.3   4.6   26.5  79.6     1.1      M    M
 15000   -4.5  23.9   255   15    8   8.4   4.6   26.2  79.2     0.8      M    M
 14500   -3.2  26.2   260   14    7   8.0   4.4   26.0  78.8     0.6      M    M
 14000   -2.1  28.2   265   13    7   7.5   4.1   25.6  78.2     0.2      M    M
 13500   -1.1  30.0   270    9    5   7.9   4.3   25.3  77.5    -0.2    680  3.5
 13000    0.2  32.4   275    6    3   8.6   4.7   25.1  77.1    -0.4    627  3.2
 12500    1.5  34.7   290    3    2   8.6   4.7   24.9  76.8    -0.6    574  2.9
 12000    2.8  37.0   355    2    1   8.6   4.7   24.7  76.5    -0.7    520  2.6
 11500    4.1  39.4   355    1    0   8.7   4.7   24.5  76.1    -0.9    467  2.4
 11000    5.2  41.4   000    0    0   4.5   2.5   24.2  75.6    -1.2    417  2.1
 10500    5.4  41.7   145    5    3   5.2   2.9   23.0  73.4    -2.5    397  2.0
 10250    6.0  42.8   145    7    4   9.6   5.3   22.9  73.2    -2.6    370  1.9
 10000    6.8  44.2   140    8    4  10.7   5.8   22.9  73.2    -2.6    342  1.7
  9750    7.5  45.5   135    7    4   7.8   4.3   22.9  73.2    -2.6    312  1.6
  9500    7.8  46.0   130    7    4   0.9   0.5   22.4  72.4    -3.1    297  1.5
  9250    7.7  45.9   125    7    4  -1.4  -0.8   21.6  70.9    -3.9    292  1.5
  9000    7.7  45.9   120    7    4   4.6   2.5   20.9  69.6    -4.7    284  1.4
  8750    8.3  46.9   125    7    4   9.0   4.9   20.8  69.4    -4.8    259  1.3
  8500    8.9  48.0   125    7    4   7.8   4.3   20.6  69.1    -5.0    233  1.2
  8250    9.5  49.1   130    7    4   8.1   4.5   20.5  68.9    -5.1    208  1.1
  8000   10.1  50.2   135    7    4   7.8   4.3   20.4  68.7    -5.2    183  0.9
  7750   10.7  51.3   140    8    4   8.8   4.8   20.2  68.4    -5.4    157  0.8
  7500   11.3  52.3   145    8    4   5.2   2.9   20.1  68.2    -5.5    132  0.7
  7250   11.4  52.5   145    9    5  -0.3  -0.2   19.5  67.1    -6.1    121  0.6
  7000   11.4  52.5   150   10    5   2.0   1.1   18.8  65.8    -6.9    114  0.6
  6750   11.7  53.1   140   10    5   5.8   3.2   18.3  65.0    -7.3     97  0.5
  6500   12.2  54.0   130   11    6   6.4   3.5   18.1  64.5    -7.6     76  0.4
  6250   12.6  54.7   125   12    6   6.2   3.4   17.8  64.1    -7.9     54  0.3
  6000   13.1  55.6   115   14    7   6.3   3.4   17.6  63.6    -8.2     33  0.2
  5750   13.6  56.5   110   12    6   6.2   3.4   17.3  63.1    -8.5     12  0.1
  5500   14.0  57.2   105   10    5   6.4   3.5   17.0  62.6    -8.7      M    M
  5250   14.5  58.1   100    8    4   5.6   3.1   16.8  62.2    -9.0      M    M
  5000   14.6  58.3   085    6    3  -3.7  -2.0   16.2  61.1    -9.7      M    M

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

           05/20/2018 at 0900 MDT          |       05/20/2018 at 1200 MDT
                                           |
K index... +25.4  LI... -2.6               | K index... +26.6  LI... -2.5
CAPE... +202.7  CIN... -20.1               | CAPE... +425.6  CIN... -36.5
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -57.8 -72.0  230  18  9   1.2   0.6 | -57.5 -71.5  225  18  9   1.0   0.6
 45000 -56.4 -69.5  240  21 11  -1.7  -0.9 | -56.1 -69.0  235  19 10   0.0   0.0
 40000 -59.1 -74.4  205  22 12  -1.6  -0.9 | -56.0 -68.8  220  22 11   0.0   0.0
 38000 -57.5 -71.5  195  21 11   4.4   2.4 | -55.4 -67.7  205  22 11   1.5   0.8
 36000 -54.9 -66.8  185  19 10   4.4   2.4 | -54.5 -66.1  180  23 12   1.5   0.8
 34000 -51.4 -60.5  175  17  9   8.5   4.7 | -51.5 -60.7  170  24 12   8.2   4.5
 32000 -45.6 -50.1  175  13  7   8.5   4.7 | -46.6 -51.9  170  20 10   8.2   4.5
 30000 -40.6 -41.1  185  10  5   8.2   4.5 | -41.6 -42.9  170  17  9   8.3   4.5
 29000 -38.1 -36.6  195   8  4   8.2   4.5 | -39.2 -38.6  170  16  8   8.3   4.5
 28000 -35.7 -32.3  205   8  4   8.2   4.5 | -36.7 -34.1  175  15  7   8.3   4.5
 27000 -33.2 -27.8  215   7  4   7.9   4.4 | -34.2 -29.6  180  13  7   8.1   4.4
 26000 -30.9 -23.6  225   7  4   7.9   4.3 | -31.8 -25.2  185  12  6   8.1   4.4
 25000 -28.5 -19.3  235   8  4   7.9   4.3 | -29.4 -20.9  200  11  6   8.1   4.4
 24000 -26.2 -15.2  240   9  5   6.5   3.6 | -27.0 -16.6  210  11  6   7.2   4.0
 23000 -24.3 -11.7  245  12  6   6.6   3.6 | -24.8 -12.6  230  12  6   7.3   4.0
 22000 -22.3  -8.1  245  15  7   6.7   3.7 | -22.6  -8.7  240  15  7   7.3   4.0
 21000 -20.3  -4.5  245  19 10   7.0   3.8 | -20.3  -4.5  245  18  9   8.1   4.4
 20000 -18.2  -0.8  250  27 14   7.1   3.9 | -17.9  -0.2  245  22 11   8.2   4.5
 19500 -17.2   1.0  250  30 16   7.1   3.9 | -16.7   1.9  245  24 12   8.3   4.5
 19000 -16.1   3.0  250  34 17   7.4   4.0 | -15.5   4.1  240  26 13   8.4   4.6
 18500 -14.9   5.2  250  33 17   9.5   5.2 | -14.3   6.3  245  25 13   8.7   4.8
 18000 -13.4   7.9  250  30 15   9.4   5.2 | -13.0   8.6  245  24 12   8.7   4.8
 17500 -12.0  10.4  250  27 14   9.1   5.0 | -11.7  10.9  245  23 12   8.6   4.7
 17000 -10.7  12.7  250  23 12   9.1   5.0 | -10.4  13.3  245  21 11   8.6   4.7
 16500  -9.4  15.1  250  19 10   8.9   4.9 |  -9.2  15.4  250  18 10   8.8   4.9
 16000  -8.2  17.2  250  16  8   8.2   4.5 |  -7.9  17.8  245  16  8   9.3   5.1
 15500  -7.0  19.4  250  15  8   8.2   4.5 |  -5.9  21.4  240  12  6   8.9   4.9
 15000  -5.1  22.8  245  13  7   9.0   4.9 |  -4.6  23.7  235  10  5   8.7   4.8
 14500  -3.8  25.2  245  12  6   9.1   5.0 |  -3.4  25.9  230   9  5   8.7   4.8
 14000  -2.5  27.5  245  11  6   9.1   5.0 |  -2.1  28.2  225   8  4   8.8   4.8
 13500  -1.1  30.0  240  10  5   9.1   5.0 |  -0.8  30.6  215   7  4   8.8   4.8
 13000   0.2  32.4  235   9  5   8.7   4.8 |   0.5  32.9  210   7  3   8.4   4.6
 12500   1.5  34.7  230   9  5   8.8   4.8 |   1.7  35.1  205   7  3   8.4   4.6
 12000   2.7  36.9  220   8  4   8.2   4.5 |   3.0  37.4  205   7  3   8.9   4.9
 11500   3.9  39.0  205   7  4   8.3   4.5 |   4.3  39.7  200   7  3   9.0   4.9
 11000   5.1  41.2  190   7  4   7.8   4.3 |   5.6  42.1  205   6  3   7.6   4.2
 10500   6.3  43.3  175   7  4   5.9   3.2 |   6.7  44.1  210   6  3   9.7   5.3
 10250   6.7  44.1  170   8  4   5.0   2.8 |   7.5  45.5  210   6  3  10.4   5.7
 10000   7.2  45.0  170   8  4   8.3   4.6 |   8.2  46.8  210   6  3   8.2   4.5
  9750   7.8  46.0  165   8  4   8.9   4.9 |   8.8  47.8  215   6  3   8.9   4.9
  9500   8.5  47.3  165   9  4   8.7   4.7 |   9.4  48.9  215   6  3   8.4   4.6
  9250   9.1  48.4  165   9  5   6.9   3.8 |  10.0  50.0  215   6  3   7.5   4.1
  9000   9.5  49.1  165   9  5   6.2   3.4 |  10.6  51.1  215   5  3   8.4   4.6
  8750  10.0  50.0  165  10  5   7.1   3.9 |  11.3  52.3  215   5  3   9.4   5.1
  8500  10.5  50.9  165  11  5   6.7   3.7 |  11.9  53.4  210   5  2   9.2   5.0
  8250  11.0  51.8  165  11  6   6.4   3.5 |  12.6  54.7  210   5  2   9.4   5.2
  8000  11.4  52.5  160  12  6   5.2   2.9 |  13.3  55.9  210   5  2   9.5   5.2
  7750  11.8  53.2  160  11  6   4.6   2.5 |  14.0  57.2  210   4  2   9.4   5.2
  7500  12.1  53.8  155  11  6   3.6   2.0 |  14.7  58.5  210   4  2   9.8   5.4
  7250  12.3  54.1  155  10  5   2.1   1.2 |  15.5  59.9  215   4  2  10.1   5.6
  7000  12.5  54.5  155  10  5   2.5   1.4 |  16.3  61.3  215   4  2  10.3   5.7
  6750  12.7  54.9  150   9  5   3.5   1.9 |  17.0  62.6  215   4  2  10.8   5.9
  6500  13.0  55.4  150   8  4   5.5   3.0 |  17.8  64.0  215   4  2  11.3   6.2
  6250  13.4  56.1  150   7  4   6.8   3.8 |  18.7  65.7  215   4  2  12.3   6.7
  6000  13.9  57.0  150   6  3   5.6   3.1 |  19.6  67.3  215   4  2  10.0   5.5
  5750  14.3  57.7  150   5  3   8.7   4.8 |  20.3  68.5  215   4  2  11.3   6.2
  5500  15.2  59.4  150   5  3  13.1   7.2 |  21.4  70.5  220   4  2  16.9   9.3
  5250  16.1  61.0  145   5  3  11.3   6.2 |  22.7  72.9  220   4  2  16.4   9.0
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/20/2018 at 1500 MDT          |       05/20/2018 at 1800 MDT
                                           |
K index... +24.8  LI... -0.4               | K index... +25.0  LI... 0.0
CAPE... +78.5  CIN... -32.2                | CAPE... +5.2  CIN... -49.9
                                           |
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 -57.9 -72.2  235  19 10   0.6   0.3 | -58.2 -72.8  240  20 10   0.6   0.3
 45000 -56.8 -70.2  240  22 12   2.2   1.2 | -57.4 -71.3  245  24 12   0.0   0.0
 40000 -53.4 -64.1  245  20 10   2.2   1.2 | -57.4 -71.3  240  26 13   0.1   0.1
 38000 -53.3 -63.9  225  18  9  -0.3  -0.2 | -56.0 -68.8  225  20 10   3.3   1.8
 36000 -53.5 -64.3  200  19 10  -0.3  -0.2 | -54.0 -65.2  190  17  9   3.3   1.8
 34000 -51.4 -60.5  185  22 11   8.6   4.7 | -50.4 -58.7  165  19 10   7.9   4.4
 32000 -46.3 -51.3  185  23 12   8.5   4.7 | -45.6 -50.1  165  18  9   7.9   4.4
 30000 -41.2 -42.2  185  24 12   8.5   4.7 | -40.6 -41.1  170  16  8   8.6   4.7
 29000 -38.7 -37.7  185  23 12   8.5   4.7 | -38.0 -36.4  180  15  8   8.6   4.7
 28000 -36.2 -33.2  185  23 12   8.5   4.7 | -35.5 -31.9  190  15  8   8.6   4.7
 27000 -33.7 -28.7  180  23 12   7.6   4.1 | -33.0 -27.4  200  16  8   8.1   4.5
 26000 -30.9 -23.6  180  22 11   7.6   4.2 | -30.5 -22.9  205  18  9   8.1   4.4
 25000 -28.6 -19.5  180  22 11   7.6   4.2 | -28.1 -18.6  210  19 10   8.1   4.4
 24000 -26.3 -15.3  180  22 11   7.6   4.2 | -25.7 -14.3  215  21 11   8.2   4.5
 23000 -24.1 -11.4  180  21 11   7.6   4.2 | -23.2  -9.8  215  22 11   8.2   4.5
 22000 -21.8  -7.2  180  21 11   7.7   4.2 | -20.8  -5.4  215  23 12   8.1   4.5
 21000 -19.5  -3.1  180  20 10   8.1   4.4 | -18.5  -1.3  220  24 12   7.0   3.8
 20000 -17.1   1.2  185  19 10   8.1   4.5 | -16.4   2.5  215  24 12   7.0   3.8
 19500 -15.9   3.4  185  18  9   8.1   4.5 | -15.4   4.3  215  24 12   7.0   3.8
 19000 -14.8   5.4  185  17  9   8.2   4.5 | -14.4   6.1  215  24 12   7.0   3.9
 18500 -13.6   7.5  185  15  8   8.3   4.5 | -13.3   8.1  215  24 12   7.7   4.2
 18000 -12.4   9.7  185  13  7   8.3   4.6 | -12.2  10.0  215  23 12   7.7   4.2
 17500 -11.2  11.8  185  11  6   7.6   4.2 | -11.0  12.2  215  23 12   8.4   4.6
 17000 -10.1  13.8  185   9  5   7.6   4.1 |  -9.8  14.4  215  21 11   8.7   4.8
 16500  -9.0  15.8  185   7  4   7.3   4.0 |  -8.5  16.7  215  19 10   8.7   4.8
 16000  -8.0  17.6  185   6  3   7.0   3.8 |  -7.3  18.9  215  16  8   8.4   4.6
 15500  -6.9  19.6  190   4  2   7.0   3.8 |  -5.5  22.1  220  12  6   7.8   4.3
 15000  -5.8  21.6  205   3  2   7.8   4.3 |  -4.5  23.9  225   9  5   7.2   4.0
 14500  -4.7  23.5  225   3  1   7.7   4.2 |  -3.4  25.9  230   7  3   7.1   3.9
 14000  -3.6  25.5  245   3  1   7.9   4.3 |  -2.4  27.7  240   5  2   6.8   3.7
 13500  -2.4  27.7  265   3  2   7.9   4.3 |  -1.4  29.5  255   3  2   6.8   3.7
 13000  -0.6  30.9  280   4  2   8.2   4.5 |  -0.4  31.3  270   2  1   7.2   4.0
 12500   0.6  33.1  280   5  3   8.2   4.5 |   0.7  33.3  290   1  1   7.2   3.9
 12000   1.9  35.4  285   6  3   9.2   5.1 |   1.8  35.2  340   1  0   7.5   4.1
 11500   3.2  37.8  285   7  4   9.1   5.0 |   2.9  37.2  060   1  0   7.4   4.1
 11000   4.6  40.3  285   8  4   8.6   4.7 |   4.1  39.4  085   2  1   7.7   4.2
 10500   5.9  42.6  285   9  5   5.7   3.1 |   5.2  41.4  095   3  1   8.1   4.5
 10250   6.2  43.2  280  10  5   6.2   3.4 |   5.8  42.4  095   3  2   5.3   2.9
 10000   6.9  44.4  280  11  5  10.6   5.8 |   6.1  43.0  100   4  2   6.0   3.3
  9750   7.6  45.7  280  11  6   9.5   5.2 |   6.7  44.1  100   5  2   9.2   5.0
  9500   8.4  47.1  280  12  6   9.5   5.2 |   7.3  45.1  105   5  3   8.4   4.6
  9250   9.0  48.2  280  12  6   8.1   4.4 |   8.0  46.4  105   6  3   8.5   4.6
  9000   9.6  49.3  275  13  7   8.2   4.5 |   8.6  47.5  105   7  4   7.9   4.3
  8750  10.3  50.5  275  14  7   9.0   4.9 |   9.1  48.4  105   8  4   7.6   4.2
  8500  10.9  51.6  275  15  7   8.8   4.8 |   9.7  49.5  105   9  5   7.6   4.2
  8250  11.6  52.9  275  15  8   9.0   4.9 |  10.3  50.5  105  10  5   7.6   4.1
  8000  12.2  54.0  275  16  8   9.1   5.0 |  10.8  51.4  105  11  6   7.4   4.0
  7750  12.9  55.2  275  16  8   9.1   5.0 |  11.4  52.5  105  12  6   7.0   3.8
  7500  13.6  56.5  270  17  9   9.4   5.2 |  11.9  53.4  105  13  7   7.7   4.2
  7250  14.3  57.7  270  18  9  10.0   5.5 |  12.5  54.5  105  13  7   8.5   4.7
  7000  15.0  59.0  270  18  9   9.6   5.3 |  13.1  55.6  105  13  7   8.6   4.7
  6750  15.7  60.3  270  18  9   9.2   5.0 |  13.8  56.8  105  13  7   9.0   4.9
  6500  16.4  61.5  270  18  9   9.9   5.4 |  14.4  57.9  105  13  7  10.2   5.6
  6250  17.2  63.0  270  18  9  10.5   5.7 |  15.3  59.5  105  13  7  11.2   6.1
  6000  17.9  64.2  270  18  9  10.4   5.7 |  16.1  61.0  105  12  6  10.1   5.6
  5750  18.7  65.7  270  18  9  10.2   5.6 |  16.8  62.2  105  12  6  10.0   5.5
  5500  19.4  66.9  270  17  9   9.7   5.3 |  17.6  63.7  105  11  6  11.4   6.2
  5250  20.1  68.2  270  16  8   9.8   5.4 |  18.5  65.3  105  11  6  11.4   6.2
  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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