Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 211241
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0640 MDT Thursday, May 21, 2015

This forecast is for Thursday, May 21, 2015:

If the trigger temperature of 70.9 F/21.6 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 10092 ft MSL (5253 ft AGL)

Forecast maximum temperature................... 73.0 F/23.2 C
Time of trigger temperature.................... 1445 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 7758 ft MSL (2919 ft AGL)
Thermal soaring outlook for Friday 05/22....... Fair

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

Remarks...

Sunrise/Sunset.................... 05:56:34 / 20:24:44 MDT
Total possible sunshine........... 14 hr 28 min 10 sec (868 min 10 sec)
Altitude of sun at 13:10:50 MDT... 71.10 degrees

Upper air data from rawinsonde observation taken on 05/21/2015 at 0600 MDT

Freezing level.................. 12491 ft MSL (7652 ft AGL)
Convective condensation level... 15063 ft MSL (10224 ft AGL)
Lifted condensation level....... 14891 ft MSL (10052 ft AGL)
Lifted index.................... -1.6
K index......................... +15.8

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  -58.6 -73.5   250   37   19  -2.1  -1.1  103.8 218.8    46.1      M    M
 45000  -58.1 -72.6   240   41   21  -6.0  -3.3   78.6 173.5    34.1      M    M
 40000  -62.8 -81.0   245   72   37   2.4   1.3   47.9 118.2    16.4      M    M
 38000  -59.8 -75.6   245   85   44   6.3   3.4   43.5 110.2    13.9      M    M
 36000  -55.5 -67.9   245   80   41   8.6   4.7   41.3 106.4    12.9      M    M
 34000  -50.3 -58.5   245   77   39   8.4   4.6   40.4 104.8    12.5      M    M
 32000  -45.7 -50.3   235   76   39   9.1   5.0   37.7  99.9    10.9      M    M
 30000  -40.6 -41.1   240   70   36   7.6   4.2   36.8  98.2    10.5      M    M
 29000  -38.4 -37.1   240   61   32   7.5   4.1   35.9  96.6     9.9      M    M
 28000  -36.4 -33.5   240   52   27   5.3   2.9   34.6  94.3     9.1      M    M
 27000  -34.4 -29.9   235   43   22   7.1   3.9   33.5  92.3     8.3      M    M
 26000  -32.8 -27.0   235   34   18   0.1   0.1   31.8  89.2     7.0      M    M
 25000  -31.3 -24.3   225   36   19   8.9   4.9   30.0  85.9     5.7      M    M
 24000  -28.9 -20.0   225   32   17   8.8   4.8   29.4  84.9     5.3      M    M
 23000  -26.6 -15.9   225   28   15   5.3   2.9   28.6  83.5     4.7      M    M
 22000  -24.9 -12.8   230   24   12   5.9   3.2   27.1  80.8     3.5      M    M
 21000  -22.7  -8.9   225   27   14   7.7   4.2   26.2  79.2     2.7      M    M
 20000  -20.4  -4.7   225   31   16   8.5   4.7   25.5  78.0     2.2      M    M
 19500  -19.1  -2.4   225   33   17   8.7   4.8   25.4  77.6     2.0      M    M
 19000  -17.8  -0.0   225   35   18   8.7   4.8   25.2  77.3     1.9      M    M
 18500  -16.5   2.3   225   34   18   9.7   5.3   25.1  77.1     1.8      M    M
 18000  -15.0   5.0   225   33   17   9.7   5.3   25.0  77.0     1.7      M    M
 17500  -12.9   8.8   225   30   16   9.7   5.3   25.0  77.0     1.7      M    M
 17000  -11.4  11.5   220   29   15   9.7   5.3   25.0  77.0     1.7      M    M
 16500  -10.1  13.8   220   27   14   8.4   4.6   24.9  76.9     1.7      M    M
 16000   -8.9  16.0   220   26   13   8.3   4.6   24.7  76.4     1.4      M    M
 15500   -7.9  17.8   220   24   12   5.6   3.1   24.2  75.5     0.9      M    M
 15000   -6.9  19.6   220   22   11   7.6   4.1   23.7  74.6     0.5      M    M
 14500   -5.8  21.6   220   21   11   8.4   4.6   23.3  73.9     0.1      M    M
 14000   -4.3  24.3   220   19   10   9.6   5.3   23.3  73.9     0.1      M    M
 13500   -2.8  27.0   220   19   10   9.7   5.3   23.2  73.8     0.1      M    M
 13000   -1.4  29.5   220   20   10   9.7   5.3   23.2  73.8     0.1      M    M
 12500    0.1  32.2   220   20   10   9.7   5.3   23.2  73.8     0.1      M    M
 12000    1.5  34.7   220   20   10   9.9   5.4   23.2  73.8     0.1      M    M
 11500    3.0  37.4   215   20   10   9.9   5.4   23.2  73.8     0.1      M    M
 11000    4.5  40.1   210   20   10   9.9   5.4   23.3  73.9     0.1      M    M
 10500    6.0  42.8   210   20   10  10.4   5.7   23.3  73.9     0.2      M    M
 10250    6.7  44.1   205   20   10   8.0   4.4   23.3  74.0     0.2      M    M
 10000    7.2  45.0   205   19   10   6.2   3.4   23.0  73.5    -0.1    373  1.9
  9750    7.7  45.9   200   18    9   7.3   4.0   22.8  73.1    -0.3    350  1.8
  9500    8.2  46.8   195   16    8   7.1   3.9   22.6  72.7    -0.5    327  1.7
  9250    8.7  47.7   190   15    8   7.2   3.9   22.4  72.4    -0.8    305  1.5
  9000    9.2  48.6   185   14    7   7.1   3.9   22.2  72.0    -1.0    282  1.4
  8750    9.7  49.5   180   13    7   7.2   4.0   22.0  71.6    -1.2    259  1.3
  8500   10.2  50.4   175   12    6   7.0   3.8   21.8  71.3    -1.4    237  1.2
  8250   10.7  51.3   165   11    6   8.0   4.4   21.6  70.9    -1.7    214  1.1
  8000   11.2  52.2   155   10    5   2.1   1.1   21.4  70.5    -1.9    193  1.0
  7750   11.0  51.8   150    9    5  -2.9  -1.6   20.4  68.8    -2.9    191  1.0
  7500   10.8  51.4   140    8    4  -2.6  -1.4   19.5  67.2    -3.8    190  1.0
  7250   10.6  51.1   130    7    4   2.5   1.4   18.7  65.6    -4.7    188  1.0
  7000   11.1  52.0   120    7    4   7.8   4.3   18.4  65.2    -5.0    166  0.8
  6750   11.6  52.9   110    7    4   6.4   3.5   18.2  64.8    -5.2    144  0.7
  6500   12.1  53.8   105    7    4   6.8   3.7   18.0  64.3    -5.5    122  0.6
  6250   12.6  54.7   100    7    4   6.5   3.6   17.7  63.9    -5.7    100  0.5
  6000   13.1  55.6   095    7    4   7.4   4.0   17.5  63.5    -6.0     78  0.4
  5750   13.5  56.3   100    6    3   4.3   2.3   17.3  63.1    -6.2     56  0.3
  5500   13.6  56.5   105    6    3  -2.7  -1.5   16.6  61.8    -7.0     48  0.2
  5250   13.1  55.6   110    5    3  -9.7  -5.3   15.4  59.7    -8.2     55  0.3
  5000   12.0  53.6   115    4    2 -18.4 -10.1   13.6  56.5   -10.1     81  0.4

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

           05/21/2015 at 0900 MDT          |       05/21/2015 at 1200 MDT
                                           |
K index... +23.2  LI... +272.6             | K index... +24.7  LI... +271.2
CAPE... +14.4  CIN... -38.9                | CAPE... +120.4  CIN... -18.2
                                           |
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 -58.6 -73.5  245  30 16   0.0   0.0 | -58.6 -73.5  240  32 17   0.4   0.2
 45000 -58.6 -73.5  245  45 23  -1.2  -0.6 | -58.1 -72.6  235  50 26  -1.3  -0.7
 40000 -60.2 -76.4  245  69 35  -1.0  -0.6 | -59.9 -75.8  235  78 40  -0.9  -0.5
 38000 -58.1 -72.6  245  70 36   5.9   3.2 | -57.6 -71.7  230  77 40   5.6   3.1
 36000 -54.5 -66.1  245  68 35   5.9   3.2 | -54.2 -65.6  230  72 37   5.6   3.1
 34000 -50.7 -59.3  240  65 33   7.4   4.1 | -50.4 -58.7  230  64 33   7.8   4.3
 32000 -45.7 -50.3  240  59 30   7.4   4.1 | -45.7 -50.3  225  51 26   7.8   4.3
 30000 -41.0 -41.8  235  53 27   8.3   4.6 | -40.7 -41.3  225  41 21   9.2   5.0
 29000 -38.5 -37.3  235  50 26   8.3   4.6 | -38.0 -36.4  225  39 20   9.1   5.0
 28000 -36.0 -32.8  235  46 24   8.3   4.6 | -35.3 -31.5  230  37 19   9.1   5.0
 27000 -33.5 -28.3  235  42 22   7.8   4.3 | -32.1 -25.8  230  36 19   7.9   4.3
 26000 -31.2 -24.2  230  39 20   7.8   4.3 | -29.7 -21.5  235  38 19   7.9   4.3
 25000 -28.9 -20.0  225  35 18   7.9   4.3 | -27.4 -17.3  235  39 20   7.9   4.3
 24000 -26.7 -16.1  220  32 17   5.6   3.1 | -25.2 -13.4  235  41 21   5.5   3.0
 23000 -25.0 -13.0  215  32 17   5.6   3.1 | -23.5 -10.3  230  43 22   5.8   3.2
 22000 -23.4 -10.1  215  33 17   5.6   3.1 | -21.8  -7.2  225  46 24   5.8   3.2
 21000 -21.6  -6.9  210  33 17   7.2   4.0 | -20.1  -4.2  220  46 24   5.3   2.9
 20000 -19.5  -3.1  210  31 16   7.1   3.9 | -18.6  -1.5  215  43 22   5.3   2.9
 19500 -18.4  -1.1  210  31 16   7.1   3.9 | -17.8  -0.0  210  42 22   5.3   2.9
 19000 -17.4   0.7  210  30 16   7.1   3.9 | -17.0   1.4  210  41 21   5.1   2.8
 18500 -16.3   2.7  210  29 15   7.8   4.3 | -16.0   3.2  205  39 20   8.5   4.7
 18000 -15.1   4.8  215  28 14   7.7   4.2 | -14.8   5.4  205  37 19   8.2   4.5
 17500 -14.0   6.8  215  26 13   7.4   4.1 | -13.6   7.5  205  35 18   7.6   4.2
 17000 -12.9   8.8  220  24 12   7.2   3.9 | -12.6   9.3  205  33 17   7.3   4.0
 16500 -11.9  10.6  220  21 11   7.2   3.9 | -11.5  11.3  205  31 16   7.2   4.0
 16000 -10.8  12.6  220  20 10   7.2   4.0 | -10.5  13.1  205  28 15   6.9   3.8
 15500  -9.2  15.4  220  18  9   8.0   4.4 |  -9.5  14.9  205  26 13   6.9   3.8
 15000  -7.8  18.0  220  17  9   9.5   5.2 |  -8.5  16.7  205  23 12   7.0   3.8
 14500  -6.4  20.5  220  17  9   9.6   5.3 |  -7.5  18.5  205  20 10   7.0   3.8
 14000  -4.9  23.2  220  17  9  10.4   5.7 |  -6.4  20.5  205  17  9   7.6   4.2
 13500  -3.4  25.9  220  16  8  10.4   5.7 |  -5.3  22.5  205  15  7   7.8   4.3
 13000  -1.9  28.6  220  16  8   9.6   5.3 |  -3.4  25.9  210  12  6   9.8   5.4
 12500  -0.4  31.3  220  16  8   9.8   5.4 |  -2.0  28.4  210  11  6   9.5   5.2
 12000   1.0  33.8  215  16  8   8.6   4.7 |  -0.5  31.1  215  10  5  10.3   5.7
 11500   2.2  36.0  215  16  8   8.6   4.7 |   1.0  33.8  220  10  5  10.5   5.7
 11000   3.5  38.3  215  16  8   8.6   4.7 |   2.4  36.3  220   9  5   8.3   4.6
 10500   4.8  40.6  215  15  8   9.4   5.2 |   3.7  38.7  225   9  4   9.4   5.1
 10250   5.4  41.7  215  15  8   5.6   3.1 |   4.5  40.1  225   8  4  12.2   6.7
 10000   5.7  42.3  210  15  8   5.7   3.1 |   5.4  41.7  225   8  4  10.8   5.9
  9750   6.4  43.5  210  14  7   9.6   5.3 |   6.0  42.8  225   8  4   8.9   4.9
  9500   7.0  44.6  205  14  7   8.8   4.8 |   6.7  44.1  225   7  4   9.5   5.2
  9250   7.6  45.7  205  14  7   7.0   3.8 |   7.4  45.3  230   7  3   7.5   4.1
  9000   8.0  46.4  200  14  7   5.8   3.2 |   7.9  46.2  230   6  3   7.4   4.1
  8750   8.5  47.3  195  13  7   7.0   3.8 |   8.5  47.3  225   5  3   8.9   4.9
  8500   9.0  48.2  190  13  7   6.5   3.6 |   9.1  48.4  220   4  2   8.3   4.6
  8250   9.4  48.9  185  13  7   5.7   3.1 |   9.7  49.5  215   4  2   7.5   4.1
  8000   9.8  49.6  180  13  7   5.0   2.8 |  10.3  50.5  205   3  2   7.3   4.0
  7750  10.2  50.4  175  13  7   5.3   2.9 |  10.8  51.4  200   3  2   7.4   4.1
  7500  10.6  51.1  165  13  6   4.3   2.4 |  11.3  52.3  195   3  2   8.1   4.5
  7250  10.8  51.4  160  12  6   2.9   1.6 |  12.0  53.6  190   3  2   9.3   5.1
  7000  11.0  51.8  160  12  6   2.9   1.6 |  12.6  54.7  190   3  2   9.5   5.2
  6750  11.3  52.3  155  11  6   3.1   1.7 |  13.3  55.9  190   3  2   9.6   5.3
  6500  11.5  52.7  150  10  5   3.9   2.2 |  14.1  57.4  195   3  2  10.4   5.7
  6250  11.8  53.2  145   8  4   4.7   2.6 |  14.9  58.8  195   3  2  11.2   6.1
  6000  12.0  53.6  140   7  3   4.0   2.2 |  15.7  60.3  195   3  2  10.1   5.5
  5750  12.3  54.1  130   5  3   6.1   3.4 |  16.4  61.5  195   3  2  10.3   5.6
  5500  12.9  55.2  125   5  3   9.2   5.1 |  17.2  63.0  200   3  2  12.3   6.7
  5250  13.6  56.5  125   5  3   8.2   4.5 |  18.1  64.6  200   3  2  12.6   6.9
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/21/2015 at 1500 MDT          |       05/21/2015 at 1800 MDT
                                           |
K index... +23.6  LI... +272.6             | K index... +27.8  LI... +272.3
CAPE... +21.7  CIN... -38.6                | CAPE... +33.9  CIN... -21.7
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -58.4 -73.1  235  31 16  -0.3  -0.2 | -57.2 -71.0  235  25 13   0.6   0.3
 45000 -58.9 -74.0  235  47 24  -0.8  -0.5 | -56.5 -69.7  230  35 18  -1.7  -0.9
 40000 -60.1 -76.2  225  77 39  -0.6  -0.3 | -59.0 -74.2  210  63 33  -1.5  -0.8
 38000 -57.8 -72.0  220  72 37   5.5   3.0 | -57.4 -71.3  210  62 32   4.4   2.4
 36000 -54.5 -66.1  215  63 32   5.5   3.0 | -54.7 -66.5  205  56 29   4.4   2.4
 34000 -50.3 -58.5  210  54 28   9.3   5.1 | -51.3 -60.3  205  49 25   8.3   4.5
 32000 -44.8 -48.6  205  44 23   9.3   5.1 | -46.3 -51.3  205  43 22   8.3   4.5
 30000 -39.4 -38.9  205  37 19   8.3   4.5 | -41.2 -42.2  210  38 20   9.4   5.2
 29000 -37.0 -34.6  210  35 18   8.3   4.6 | -38.3 -36.9  215  37 19   9.4   5.2
 28000 -34.5 -30.1  215  34 18   8.3   4.6 | -35.5 -31.9  220  36 19   9.5   5.2
 27000 -31.6 -24.9  220  35 18   6.5   3.5 | -32.3 -26.1  225  37 19   7.1   3.9
 26000 -29.7 -21.5  225  37 19   6.5   3.5 | -30.1 -22.2  220  41 21   7.2   4.0
 25000 -27.8 -18.0  230  39 20   6.5   3.5 | -28.0 -18.4  220  44 23   7.2   4.0
 24000 -25.9 -14.6  230  40 21   6.6   3.6 | -25.8 -14.4  220  46 24   7.8   4.3
 23000 -23.9 -11.0  225  39 20   6.6   3.6 | -23.5 -10.3  220  44 23   7.8   4.3
 22000 -22.0  -7.6  225  37 19   6.6   3.6 | -21.2  -6.2  220  43 22   7.8   4.3
 21000 -20.0  -4.0  220  36 19   6.8   3.7 | -19.0  -2.2  215  41 21   6.4   3.5
 20000 -18.0  -0.4  215  37 19   6.8   3.7 | -17.1   1.2  215  40 21   6.5   3.6
 19500 -16.9   1.6  215  38 19   6.8   3.7 | -16.2   2.8  210  40 20   6.5   3.6
 19000 -15.9   3.4  215  38 20   6.7   3.7 | -15.2   4.6  210  39 20   6.4   3.5
 18500 -14.9   5.2  210  38 20   7.1   3.9 | -14.2   6.4  210  38 20   7.1   3.9
 18000 -13.9   7.0  205  37 19   7.1   3.9 | -13.2   8.2  205  37 19   7.1   3.9
 17500 -12.8   9.0  200  37 19   7.7   4.2 | -12.2  10.0  205  35 18   7.3   4.0
 17000 -11.7  10.9  200  35 18   8.1   4.4 | -11.1  12.0  200  33 17   7.5   4.1
 16500 -10.5  13.1  195  34 17   8.1   4.4 | -10.0  14.0  200  30 15   7.5   4.1
 16000  -9.3  15.3  195  32 16   7.9   4.4 |  -9.0  15.8  195  28 14   7.5   4.1
 15500  -8.2  17.2  195  29 15   8.0   4.4 |  -7.9  17.8  190  25 13   7.5   4.1
 15000  -7.0  19.4  195  27 14   7.8   4.3 |  -6.8  19.8  190  23 12   7.3   4.0
 14500  -5.9  21.4  195  24 12   7.8   4.3 |  -5.8  21.6  185  21 11   7.3   4.0
 14000  -4.8  23.4  190  22 11   7.7   4.2 |  -4.7  23.5  180  19 10   7.4   4.0
 13500  -3.7  25.3  190  20 10   7.6   4.2 |  -3.1  26.4  175  18  9   7.3   4.0
 13000  -2.0  28.4  180  18  9   7.9   4.3 |  -1.9  28.6  170  17  9   8.8   4.9
 12500  -0.8  30.6  180  17  9   7.8   4.3 |  -0.6  30.9  170  17  9   8.9   4.9
 12000   0.3  32.5  175  16  8   8.4   4.6 |   0.7  33.3  170  16  8   9.2   5.1
 11500   1.6  34.9  170  15  8   8.5   4.7 |   2.1  35.8  170  15  8   9.4   5.1
 11000   2.8  37.0  170  13  7   7.6   4.2 |   3.4  38.1  165  13  7   7.8   4.3
 10500   3.9  39.0  165  11  6   7.5   4.1 |   4.6  40.3  165  11  6   7.5   4.1
 10250   4.5  40.1  165  10  5  10.1   5.5 |   5.2  41.4  165  10  5  10.1   5.6
 10000   5.3  41.5  160   8  4   9.5   5.2 |   6.0  42.8  160   8  4   9.7   5.3
  9750   5.9  42.6  160   7  3   6.9   3.8 |   6.6  43.9  160   7  4   7.4   4.0
  9500   6.4  43.5  155   5  3   7.9   4.3 |   7.2  45.0  155   6  3   8.3   4.5
  9250   7.0  44.6  150   3  2   6.7   3.7 |   7.8  46.0  155   4  2   6.9   3.8
  9000   7.4  45.3  155   2  1   6.4   3.5 |   8.2  46.8  165   3  1   5.9   3.2
  8750   8.0  46.4  160   1  0   7.1   3.9 |   8.7  47.7  185   2  1   6.5   3.6
  8500   8.5  47.3  000   0  0   7.0   3.8 |   9.1  48.4  235   1  1   5.5   3.0
  8250   9.0  48.2  310   1  1   9.7   5.3 |   9.6  49.3  275   2  1   9.1   5.0
  8000   9.8  49.6  310   1  1  10.4   5.7 |  10.4  50.7  275   3  1  10.8   5.9
  7750  10.5  50.9  310   2  1   9.0   4.9 |  11.1  52.0  275   3  1   8.4   4.6
  7500  11.2  52.2  310   2  1   9.6   5.3 |  11.7  53.1  275   3  2   9.1   5.0
  7250  11.9  53.4  310   2  1  10.2   5.6 |  12.4  54.3  280   4  2  10.1   5.5
  7000  12.7  54.9  305   2  1  10.2   5.6 |  13.2  55.8  280   4  2  10.3   5.6
  6750  13.4  56.1  305   3  1   9.5   5.2 |  13.9  57.0  275   4  2   9.1   5.0
  6500  14.2  57.6  305   3  1  10.5   5.7 |  14.6  58.3  275   4  2   9.7   5.3
  6250  15.0  59.0  300   3  1  11.7   6.4 |  15.4  59.7  275   4  2  11.0   6.0
  6000  15.8  60.4  300   3  2  10.7   5.9 |  16.2  61.2  275   4  2  10.8   5.9
  5750  16.6  61.9  295   3  2  11.0   6.0 |  17.0  62.6  275   4  2   9.9   5.5
  5500  17.5  63.5  295   3  2  13.4   7.4 |  17.7  63.9  275   4  2   9.3   5.1
  5250  18.6  65.5  300   3  2  14.8   8.1 |  18.3  64.9  275   4  2   9.3   5.1
  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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