Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 231241
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0641 MDT Wednesday, May 23, 2018

This forecast is for Wednesday, May 23, 2018:

If the trigger temperature of 70.6 F/21.5 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1430 ft/min (7.3 m/s)
   Maximum height of thermals.................. 20054 ft MSL (15211 ft AGL)

Forecast maximum temperature................... 82.0 F/28.2 C
Time of trigger temperature.................... 1045 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 14416 ft MSL (9574 ft AGL)
Thermal soaring outlook for Thursday 05/24..... Excellent

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

Remarks...

Sunrise/Sunset.................... 05:54:58 / 20:26:40 MDT
Total possible sunshine........... 14 hr 31 min 42 sec (871 min 42 sec)
Altitude of sun at 13:11:01 MDT... 71.54 degrees

Upper air data from rawinsonde observation taken on 05/23/2018 at 0600 MDT

Freezing level.................. 12788 ft MSL (7945 ft AGL)
Convective condensation level... 13140 ft MSL (8297 ft AGL)
Lifted condensation level....... 14755 ft MSL (9912 ft AGL)
Lifted index.................... -5.8
K index......................... +20.6

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  -57.0 -70.6   210   18    9  -5.6  -3.0  104.0 219.3    43.7      M    M
 45000  -56.6 -69.9   205   37   19   2.5   1.3   80.0 176.0    32.0      M    M
 40000  -55.3 -67.5   205   56   29   2.8   1.5   58.0 136.3    19.9      M    M
 38000  -53.4 -64.1   205   65   34   3.1   1.7   51.8 125.2    16.3      M    M
 36000  -51.4 -60.5   205   72   37   5.3   2.9   46.5 115.7    13.0      M    M
 34000  -48.9 -56.0   205   60   31   2.7   1.5   41.7 107.1     9.9      M    M
 32000  -45.8 -50.4   205   50   26   7.7   4.2   37.8 100.1     7.3      M    M
 30000  -40.7 -41.3   205   44   23   9.1   5.0   36.0  96.7     6.2      M    M
 29000  -38.0 -36.4   205   43   22   9.0   4.9   35.6  96.1     6.0      M    M
 28000  -35.3 -31.5   205   43   22   9.1   5.0   35.3  95.6     5.8      M    M
 27000  -32.9 -27.2   210   42   22   7.6   4.2   34.6  94.3     5.3      M    M
 26000  -30.7 -23.3   210   42   21   7.7   4.2   33.8  92.8     4.7      M    M
 25000  -28.4 -19.1   210   41   21   7.7   4.2   33.1  91.6     4.2      M    M
 24000  -26.0 -14.8   215   39   20   8.3   4.5   32.4  90.4     3.7      M    M
 23000  -24.2 -11.6   210   36   19   0.1   0.0   31.2  88.1     2.7      M    M
 22000  -22.4  -8.3   215   37   19   8.2   4.5   29.7  85.5     1.6      M    M
 21000  -20.1  -4.2   220   39   20   7.2   3.9   29.0  84.3     1.0      M    M
 20000  -18.2  -0.8   205   42   21   4.8   2.6   28.0  82.3     0.0      M    M
 19500  -17.4   0.7   205   44   23   5.9   3.3   27.2  81.0    -0.7   1393  7.1
 19000  -16.5   2.3   200   47   24   5.6   3.1   26.6  79.8    -1.3   1352  6.9
 18500  -15.4   4.3   200   44   23   9.6   5.3   26.2  79.1    -1.6   1304  6.6
 18000  -14.0   6.8   205   42   21   9.2   5.1   26.1  78.9    -1.7   1248  6.3
 17500  -12.7   9.1   205   39   20   8.9   4.9   26.0  78.8    -1.8   1192  6.1
 17000  -11.4  11.5   210   37   19   8.7   4.8   25.8  78.4    -2.0   1139  5.8
 16500   -9.5  14.9   210   34   18   8.7   4.8   25.5  78.0    -2.3   1059  5.4
 16000   -8.2  17.2   215   32   17   8.7   4.8   25.4  77.7    -2.4   1005  5.1
 15500   -6.9  19.6   215   30   15   8.7   4.8   25.2  77.3    -2.6    952  4.8
 15000   -5.6  21.9   210   27   14   8.7   4.8   25.0  77.0    -2.8    899  4.6
 14500   -4.3  24.3   210   25   13   8.8   4.8   24.8  76.7    -3.0    845  4.3
 14000   -3.0  26.6   205   22   12   8.8   4.8   24.7  76.5    -3.2    791  4.0
 13500   -1.7  28.9   205   19   10   8.8   4.8   24.5  76.2    -3.4    738  3.7
 13000   -0.4  31.3   205   16    8   8.8   4.8   24.4  75.9    -3.6    684  3.5
 12500    0.9  33.6   200   12    6   8.8   4.8   24.2  75.6    -3.7    631  3.2
 12000    2.2  36.0   200    9    5   8.8   4.9   24.1  75.4    -3.9    577  2.9
 11500    3.5  38.3   195   10    5   8.9   4.9   23.9  75.1    -4.1    524  2.7
 11000    4.7  40.5   190   11    5   8.1   4.5   23.8  74.8    -4.3    471  2.4
 10500    5.8  42.4   185   11    6   7.7   4.2   23.4  74.2    -4.7    423  2.1
 10250    6.4  43.5   180   12    6   8.1   4.4   23.3  73.9    -4.9    399  2.0
 10000    7.0  44.6   180   12    6   8.9   4.9   23.2  73.8    -5.0    374  1.9
  9750    7.6  45.7   170   13    7   9.0   4.9   23.1  73.6    -5.1    347  1.8
  9500    8.3  46.9   165   15    8   9.2   5.0   23.1  73.5    -5.2    320  1.6
  9250    8.9  48.0   160   16    8   6.4   3.5   23.0  73.3    -5.4    295  1.5
  9000    9.3  48.7   155   18    9   7.0   3.8   22.6  72.8    -5.7    277  1.4
  8750    9.5  49.1   155   17    9  -3.9  -2.2   22.2  72.0    -6.2    261  1.3
  8500    8.8  47.8   160   16    8  -6.0  -3.3   20.7  69.3    -7.7    275  1.4
  8250    8.9  48.0   160   15    8   6.6   3.6   20.2  68.3    -8.3    264  1.3
  8000    9.4  48.9   165   14    7   6.8   3.7   19.9  67.9    -8.5    242  1.2
  7750    9.8  49.6   160   13    7   1.6   0.9   19.6  67.2    -8.9    224  1.1
  7500    9.7  49.5   155   11    6   0.0   0.0   18.8  65.8    -9.8    220  1.1
  7250    9.9  49.8   145   10    5   5.9   3.2   18.3  64.9   -10.4    207  1.1
  7000   10.4  50.7   135    9    5   7.5   4.1   18.1  64.5   -10.6    184  0.9
  6750   10.9  51.6   130    9    5   7.0   3.9   17.9  64.2   -10.8    160  0.8
  6500   11.5  52.7   120    9    4   7.1   3.9   17.7  63.8   -11.0    137  0.7
  6250   12.0  53.6   110    9    4   7.2   4.0   17.5  63.5   -11.3    114  0.6
  6000   12.5  54.5   100    9    5   6.8   3.7   17.3  63.1   -11.5     91  0.5
  5750   13.0  55.4   100    8    4   8.3   4.6   17.1  62.8   -11.7     67  0.3
  5500   13.6  56.5   095    7    4   2.6   1.4   16.9  62.4   -11.9     44  0.2
  5250   13.4  56.1   095    7    3  -3.6  -2.0   16.0  60.8   -12.9     42  0.2
  5000   13.0  55.4   090    6    3  -8.1  -4.4   14.9  58.9   -14.0     45  0.2

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

           05/23/2018 at 0900 MDT          |       05/23/2018 at 1200 MDT
                                           |
K index... +24.2  LI... -1.1               | K index... +25.8  LI... -1.4
CAPE... +41.8  CIN... -69.8                | CAPE... +109.7  CIN... -19.9
                                           |
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 -57.7 -71.9  210  24 12   0.6   0.3 | -58.1 -72.6  215  27 14   0.4   0.2
 45000 -56.8 -70.2  215  35 18   1.1   0.6 | -57.4 -71.3  220  38 20   1.4   0.8
 40000 -55.0 -67.0  220  64 33   1.0   0.6 | -55.1 -67.2  225  65 33   1.2   0.7
 38000 -52.6 -62.7  215  70 36   4.6   2.5 | -52.5 -62.5  225  71 36   5.1   2.8
 36000 -49.9 -57.8  215  76 39   4.6   2.5 | -49.5 -57.1  225  76 39   5.1   2.8
 34000 -47.1 -52.8  215  74 38   4.8   2.6 | -46.5 -51.7  220  76 39   4.8   2.6
 32000 -44.3 -47.7  215  62 32   4.8   2.6 | -43.6 -46.5  225  66 34   4.8   2.6
 30000 -40.8 -41.4  215  52 27   7.5   4.1 | -40.3 -40.5  225  58 30   6.7   3.7
 29000 -38.6 -37.5  220  49 25   7.5   4.1 | -37.8 -36.0  225  52 27   6.6   3.6
 28000 -35.8 -32.4  220  44 23   7.5   4.1 | -35.9 -32.6  225  48 25   6.7   3.7
 27000 -33.5 -28.3  220  42 22   7.9   4.3 | -33.7 -28.7  230  45 23   7.7   4.2
 26000 -31.1 -24.0  220  41 21   7.9   4.3 | -31.4 -24.5  230  43 22   7.7   4.2
 25000 -28.8 -19.8  220  40 20   7.9   4.3 | -29.1 -20.4  230  40 21   7.7   4.2
 24000 -26.5 -15.7  220  38 20   7.2   4.0 | -26.7 -16.1  230  39 20   8.4   4.6
 23000 -24.3 -11.7  215  36 19   7.3   4.0 | -24.2 -11.6  225  38 19   8.3   4.6
 22000 -22.1  -7.8  215  34 17   7.3   4.0 | -21.8  -7.2  225  37 19   8.3   4.6
 21000 -20.1  -4.2  215  32 17   6.2   3.4 | -19.5  -3.1  225  36 19   6.6   3.6
 20000 -18.2  -0.8  210  32 16   6.3   3.4 | -17.6   0.3  225  34 18   6.6   3.6
 19500 -17.3   0.9  210  31 16   6.3   3.4 | -16.6   2.1  220  33 17   6.6   3.6
 19000 -16.3   2.7  210  31 16   6.3   3.4 | -15.7   3.7  220  33 17   6.6   3.6
 18500 -15.4   4.3  205  31 16   7.1   3.9 | -14.7   5.5  220  31 16   6.7   3.7
 18000 -14.4   6.1  205  31 16   7.1   3.9 | -13.7   7.3  220  29 15   6.7   3.7
 17500 -13.3   8.1  205  30 16   7.9   4.4 | -12.7   9.1  220  26 14   7.3   4.0
 17000 -12.1  10.2  205  28 14   8.3   4.6 | -11.7  10.9  220  24 13   7.6   4.2
 16500 -10.9  12.4  200  26 13   8.5   4.7 | -10.6  12.9  225  22 12   7.7   4.2
 16000  -9.7  14.5  200  24 12   8.8   4.9 |  -9.4  15.1  220  21 11   7.9   4.3
 15500  -8.4  16.9  200  22 11   8.8   4.8 |  -8.3  17.1  220  19 10   7.9   4.3
 15000  -7.1  19.2  200  20 10   9.3   5.1 |  -7.1  19.2  215  18  9   8.2   4.5
 14500  -5.7  21.7  200  19 10   9.3   5.1 |  -5.9  21.4  215  17  9   8.1   4.5
 14000  -4.3  24.3  205  18  9   9.2   5.1 |  -4.0  24.8  215  16  8   9.0   4.9
 13500  -2.3  27.9  205  16  8   9.2   5.0 |  -2.7  27.1  215  16  8   9.0   4.9
 13000  -1.0  30.2  205  15  8   8.8   4.8 |  -1.3  29.7  215  15  8   9.3   5.1
 12500   0.4  32.7  210  14  7   8.8   4.8 |   0.0  32.0  215  15  8   9.3   5.1
 12000   1.6  34.9  215  13  7   8.7   4.8 |   1.4  34.5  215  14  7   9.1   5.0
 11500   2.9  37.2  215  13  7   8.9   4.9 |   2.8  37.0  215  13  7   9.1   5.0
 11000   4.1  39.4  220  12  6   7.7   4.2 |   4.1  39.4  215  13  7   8.6   4.7
 10500   5.3  41.5  220  12  6   8.3   4.6 |   5.4  41.7  215  12  6   5.1   2.8
 10250   5.9  42.6  220  12  6   5.7   3.1 |   5.7  42.3  220  12  6   5.6   3.1
 10000   6.2  43.2  220  11  6   6.0   3.3 |   6.4  43.5  220  11  6  10.7   5.9
  9750   6.8  44.2  220  11  6   8.8   4.8 |   7.1  44.8  220  10  5   9.4   5.2
  9500   7.4  45.3  220  11  6   8.1   4.5 |   7.8  46.0  220  10  5   9.5   5.2
  9250   8.0  46.4  220  11  6   6.5   3.6 |   8.4  47.1  220   9  5   8.0   4.4
  9000   8.4  47.1  220  11  6   6.2   3.4 |   9.0  48.2  225   8  4   8.4   4.6
  8750   8.9  48.0  220  11  5   7.5   4.1 |   9.7  49.5  225   7  4   9.4   5.2
  8500   9.5  49.1  220  11  5   6.9   3.8 |  10.3  50.5  230   7  3   9.2   5.0
  8250   9.9  49.8  215  11  5   5.9   3.2 |  11.0  51.8  230   6  3   9.1   5.0
  8000  10.3  50.5  215  10  5   5.2   2.9 |  11.6  52.9  235   6  3   9.3   5.1
  7750  10.7  51.3  210  10  5   5.4   3.0 |  12.4  54.3  235   6  3   9.4   5.2
  7500  11.1  52.0  205  10  5   5.0   2.7 |  13.1  55.6  235   6  3   9.9   5.4
  7250  11.5  52.7  205  10  5   4.5   2.5 |  13.8  56.8  240   6  3  10.7   5.9
  7000  11.8  53.2  200   9  5   4.3   2.4 |  14.6  58.3  240   6  3  10.3   5.6
  6750  12.1  53.8  200   8  4   3.9   2.1 |  15.4  59.7  240   6  3   9.9   5.4
  6500  12.4  54.3  200   7  3   7.5   4.1 |  16.1  61.0  240   6  3  10.9   6.0
  6250  13.1  55.6  200   6  3  10.6   5.8 |  17.0  62.6  240   6  3  12.0   6.6
  6000  13.8  56.8  200   6  3   9.1   5.0 |  17.9  64.2  245   6  3  10.4   5.7
  5750  14.4  57.9  200   5  3   9.7   5.3 |  18.6  65.5  245   6  3  12.5   6.9
  5500  15.2  59.4  205   5  2  11.5   6.3 |  19.8  67.6  245   6  3  17.1   9.4
  5250  16.1  61.0  205   5  2  11.5   6.3 |  21.0  69.8  245   6  3  16.0   8.8
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/23/2018 at 1500 MDT          |       05/23/2018 at 1800 MDT
                                           |
K index... +26.0  LI... -0.9               | K index... +28.0  LI... -1.0
CAPE... +34.7  CIN... -41.9                | CAPE... +80.9  CIN... -27.7
                                           |
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 -58.8 -73.8  220  25 13   0.3   0.2 | -58.6 -73.5  225  21 11   0.9   0.5
 45000 -58.0 -72.4  230  36 19   1.6   0.9 | -57.2 -71.0  235  31 16   1.0   0.6
 40000 -55.6 -68.1  235  60 31   1.3   0.7 | -55.7 -68.3  245  57 29   0.8   0.4
 38000 -53.0 -63.4  235  64 33   4.8   2.7 | -53.6 -64.5  240  58 30   3.9   2.1
 36000 -50.1 -58.2  230  68 35   4.8   2.7 | -51.2 -60.2  240  58 30   3.9   2.1
 34000 -47.0 -52.6  230  65 34   5.3   2.9 | -48.1 -54.6  240  54 28   6.7   3.7
 32000 -43.8 -46.8  235  56 29   5.3   2.9 | -44.1 -47.4  240  46 24   6.7   3.7
 30000 -39.5 -39.1  240  47 24   7.6   4.2 | -39.2 -38.6  245  41 21   7.8   4.3
 29000 -37.3 -35.1  245  44 23   7.6   4.2 | -36.9 -34.4  245  41 21   7.8   4.3
 28000 -35.0 -31.0  245  41 21   7.6   4.2 | -34.5 -30.1  250  40 21   7.8   4.3
 27000 -32.6 -26.7  250  39 20   8.2   4.5 | -32.1 -25.8  250  39 20   8.3   4.6
 26000 -30.2 -22.4  245  38 19   8.2   4.5 | -29.6 -21.3  245  38 19   8.3   4.6
 25000 -27.7 -17.9  245  36 19   8.2   4.5 | -27.1 -16.8  245  36 19   8.3   4.6
 24000 -25.2 -13.4  240  34 18   8.3   4.6 | -24.7 -12.5  245  34 18   7.7   4.2
 23000 -22.7  -8.9  240  33 17   8.3   4.6 | -22.4  -8.3  240  32 17   7.7   4.2
 22000 -20.3  -4.5  235  31 16   8.2   4.5 | -20.1  -4.2  240  31 16   7.7   4.2
 21000 -18.1  -0.6  235  30 16   6.1   3.3 | -18.0  -0.4  235  30 15   6.8   3.7
 20000 -16.4   2.5  235  31 16   6.1   3.3 | -16.0   3.2  235  29 15   6.9   3.8
 19500 -15.5   4.1  235  32 16   6.1   3.4 | -15.0   5.0  235  29 15   7.0   3.8
 19000 -14.6   5.7  230  32 17   6.4   3.5 | -14.0   6.8  235  29 15   7.4   4.1
 18500 -13.6   7.5  230  31 16   7.5   4.1 | -12.8   9.0  235  27 14   8.5   4.7
 18000 -12.5   9.5  230  30 16   7.5   4.1 | -11.6  11.1  235  25 13   8.5   4.7
 17500 -11.4  11.5  225  29 15   8.2   4.5 | -10.4  13.3  230  24 12   8.4   4.6
 17000 -10.2  13.6  220  27 14   8.4   4.6 |  -9.2  15.4  230  23 12   8.4   4.6
 16500  -9.0  15.8  215  26 13   8.5   4.7 |  -8.0  17.6  225  22 11   8.2   4.5
 16000  -7.8  18.0  215  25 13   8.7   4.8 |  -6.8  19.8  225  21 11   7.9   4.4
 15500  -6.5  20.3  210  24 12   8.8   4.8 |  -5.7  21.7  220  20 11   7.9   4.3
 15000  -5.3  22.5  210  23 12   7.6   4.2 |  -4.5  23.9  220  20 10   7.6   4.2
 14500  -3.6  25.5  205  22 11   7.9   4.3 |  -2.8  27.0  220  18  9   8.2   4.5
 14000  -2.4  27.7  205  21 11   8.1   4.5 |  -1.5  29.3  220  17  9   8.9   4.9
 13500  -1.2  29.8  205  20 10   8.2   4.5 |  -0.2  31.6  215  17  9   8.9   4.9
 13000   0.1  32.2  205  19 10   9.0   4.9 |   1.1  34.0  215  16  8   8.4   4.6
 12500   1.4  34.5  205  18  9   8.9   4.9 |   2.4  36.3  220  15  8   8.5   4.7
 12000   2.6  36.7  205  17  9   7.6   4.2 |   3.7  38.7  220  14  7   9.0   4.9
 11500   3.8  38.8  210  15  8   7.7   4.2 |   5.0  41.0  220  13  7   9.0   4.9
 11000   4.9  40.8  210  13  7   7.8   4.3 |   6.2  43.2  225  12  6   7.9   4.3
 10500   6.1  43.0  215  11  6   4.4   2.4 |   7.4  45.3  230  11  6  11.3   6.2
 10250   6.3  43.3  220  10  5   5.0   2.8 |   8.4  47.1  230  11  5  11.3   6.2
 10000   7.0  44.6  225   9  5  10.1   5.5 |   9.0  48.2  235  10  5   6.9   3.8
  9750   7.7  45.9  230   9  5   8.8   4.8 |   9.5  49.1  235   9  5   8.1   4.5
  9500   8.3  46.9  240   8  4   9.1   5.0 |  10.1  50.2  240   9  5   7.6   4.2
  9250   9.0  48.2  245   8  4   8.7   4.8 |  10.7  51.3  245   8  4   7.0   3.9
  9000   9.6  49.3  250   8  4   8.7   4.8 |  11.2  52.2  250   7  4   7.4   4.1
  8750  10.3  50.5  255   8  4   8.9   4.9 |  11.8  53.2  260   6  3   7.8   4.3
  8500  10.9  51.6  260   8  4   9.0   4.9 |  12.3  54.1  270   5  3   7.9   4.3
  8250  11.6  52.9  265   8  4   9.2   5.1 |  12.9  55.2  280   5  2   8.4   4.6
  8000  12.3  54.1  265   8  4   9.7   5.3 |  13.6  56.5  290   5  2   9.0   4.9
  7750  13.1  55.6  265   8  4   9.9   5.4 |  14.3  57.7  290   5  2   9.2   5.1
  7500  13.8  56.8  270   8  4  10.1   5.5 |  15.0  59.0  295   5  2   9.6   5.3
  7250  14.6  58.3  270   8  4  10.6   5.8 |  15.7  60.3  295   5  2  10.3   5.7
  7000  15.4  59.7  270   8  4  10.1   5.5 |  16.5  61.7  295   5  2   9.8   5.3
  6750  16.1  61.0  270   8  4   9.6   5.3 |  17.2  63.0  295   5  2   9.1   5.0
  6500  16.8  62.2  270   8  4  10.8   6.0 |  17.9  64.2  295   5  2  10.2   5.6
  6250  17.7  63.9  270   8  4  12.3   6.8 |  18.7  65.7  295   5  2  11.0   6.1
  6000  18.6  65.5  270   8  4  10.0   5.5 |  19.5  67.1  295   5  2  10.5   5.7
  5750  19.3  66.7  275   8  4  11.7   6.4 |  20.3  68.5  295   4  2  10.6   5.8
  5500  20.4  68.7  270   8  4  17.1   9.4 |  21.1  70.0  295   4  2  11.4   6.3
  5250  21.7  71.1  270   8  4  16.0   8.8 |  22.0  71.6  295   5  2  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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