Soaring Guidance
Issued by NWS Grand Junction, CO

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345
UXUS97 KGJT 231301
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0701 MDT Sunday, April 23, 2017

This forecast is for Sunday, April 23, 2017:

If the trigger temperature of 64.3 F/18.0 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 360 ft/min (1.8 m/s)
   Maximum height of thermals.................. 13230 ft MSL (8391 ft AGL)

Forecast maximum temperature................... 79.0 F/26.6 C
Time of trigger temperature.................... 1030 MDT
Time of overdevelopment........................ None
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................. 11734 ft MSL (6895 ft AGL)
Thermal soaring outlook for Monday 04/24....... Fair

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

Remarks...

Sunrise/Sunset.................... 06:25:48 / 19:58:43 MDT
Total possible sunshine........... 13 hr 32 min 55 sec (812 min 55 sec)
Altitude of sun at 13:12:25 MDT... 63.67 degrees

Upper air data from rawinsonde observation taken on 04/23/2017 at 0600 MDT

Freezing level.................. 13600 ft MSL (8761 ft AGL)
Convective condensation level... 20924 ft MSL (16085 ft AGL)
Lifted condensation level....... 18828 ft MSL (13989 ft AGL)
Lifted index.................... +3.7
K index......................... -11.5

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  -64.5 -84.1   270   35   18   4.8   2.6   92.9 199.2    38.1      M    M
 45000  -68.6 -91.5   260   53   27 -12.0  -6.6   61.3 142.4    21.6      M    M
 40000  -64.4 -83.9   260   60   31   0.7   0.4   44.8 112.7    12.3      M    M
 38000  -60.2 -76.4   255   54   28   8.8   4.8   42.2 107.9    10.8      M    M
 36000  -54.8 -66.6   250   47   24   9.7   5.3   41.7 107.0    10.8      M    M
 34000  -48.3 -54.9   255   47   24   8.3   4.6   41.4 106.4    10.9      M    M
 32000  -43.4 -46.1   260   48   25   8.3   4.5   40.1 104.2    10.3      M    M
 30000  -38.9 -38.0   260   50   26   6.7   3.7   38.5 101.3     9.3      M    M
 29000  -37.2 -35.0   260   50   26   4.0   2.2   36.9  98.3     8.2      M    M
 28000  -34.8 -30.6   260   49   25   9.1   5.0   36.2  97.1     7.7      M    M
 27000  -32.1 -25.8   255   49   25   8.6   4.7   35.8  96.4     7.5      M    M
 26000  -29.5 -21.1   255   48   25   8.6   4.7   35.3  95.6     7.3      M    M
 25000  -26.9 -16.4   255   48   25   8.7   4.8   35.0  94.9     7.0      M    M
 24000  -24.3 -11.7   255   45   23   9.1   5.0   34.6  94.3     6.8      M    M
 23000  -21.7  -7.1   255   42   22   8.3   4.6   34.1  93.4     6.5      M    M
 22000  -19.2  -2.6   255   40   20   8.3   4.6   33.6  92.5     6.2      M    M
 21000  -16.9   1.6   250   37   19   6.7   3.7   32.9  91.3     5.7      M    M
 20000  -14.9   5.2   250   34   18   6.8   3.7   31.9  89.5     4.9      M    M
 19500  -13.8   7.2   250   34   18   6.8   3.7   31.4  88.5     4.5      M    M
 19000  -12.8   9.0   255   35   18   6.9   3.8   30.9  87.6     4.0      M    M
 18500  -11.4  11.5   255   32   17   6.0   3.3   30.0  85.9     3.2      M    M
 18000  -10.6  12.9   255   30   15   6.2   3.4   29.3  84.8     2.7      M    M
 17500   -9.4  15.1   250   27   14   8.6   4.7   29.0  84.1     2.4      M    M
 17000   -8.2  17.2   250   25   13   8.4   4.6   28.7  83.7     2.2      M    M
 16500   -6.9  19.6   255   24   13   8.4   4.6   28.5  83.3     2.0      M    M
 16000   -5.6  21.9   260   24   12   8.4   4.6   28.3  82.9     1.8      M    M
 15500   -4.4  24.1   250   24   13   7.9   4.3   28.0  82.4     1.6      M    M
 15000   -3.2  26.2   245   25   13   7.9   4.4   27.7  81.8     1.3      M    M
 14500   -2.0  28.4   235   27   14   7.9   4.4   27.4  81.3     1.0      M    M
 14000   -0.8  30.6   230   28   14   7.8   4.3   27.1  80.8     0.8      M    M
 13500    0.3  32.5   230   29   15   5.8   3.2   26.8  80.2     0.5      M    M
 13000    0.7  33.3   235   30   15   3.6   2.0   25.8  78.4    -0.6    545  2.8
 12500    1.2  34.2   235   30   16   3.4   1.9   24.7  76.5    -1.5    515  2.6
 12000    1.8  35.2   235   31   16   3.4   1.9   23.7  74.7    -2.5    485  2.5
 11500    2.2  36.0   240   27   14   1.9   1.1   22.7  72.9    -3.5    457  2.3
 11000    2.4  36.3   245   24   12   1.1   0.6   21.2  70.2    -4.8    437  2.2
 10500    2.9  37.2   235   18    9   7.1   3.9   20.2  68.4    -5.8    408  2.1
 10250    3.5  38.3   230   15    8   9.0   4.9   20.1  68.2    -5.9    381  1.9
 10000    4.1  39.4   230   14    7   8.0   4.4   20.0  68.0    -6.1    356  1.8
  9750    4.6  40.3   220   13    7   5.8   3.2   19.8  67.7    -6.3    332  1.7
  9500    5.0  41.0   210   13    7   4.1   2.2   19.4  66.9    -6.7    315  1.6
  9250    5.3  41.5   200   13    7   4.4   2.4   19.0  66.2    -7.2    298  1.5
  9000    5.6  42.1   190   14    7   4.9   2.7   18.6  65.4    -7.6    281  1.4
  8750    6.1  43.0   180   14    7   8.0   4.4   18.3  64.9    -7.9    260  1.3
  8500    6.8  44.2   170   14    7   9.5   5.2   18.2  64.8    -7.9    232  1.2
  8250    7.4  45.3   165   15    8   9.1   5.0   18.2  64.8    -8.0    204  1.0
  8000    8.1  46.6   155   16    8   9.3   5.1   18.2  64.7    -8.1    176  0.9
  7750    8.8  47.8   155   16    8   9.0   4.9   18.1  64.6    -8.1    148  0.7
  7500    9.5  49.1   160   17    9   9.9   5.4   18.1  64.5    -8.2    120  0.6
  7250   10.2  50.4   160   17    9   6.6   3.6   18.0  64.5    -8.2     91  0.5
  7000   10.3  50.5   165   18    9  -5.9  -3.2   17.4  63.3    -8.9     82  0.4
  6750    9.5  49.1   165   19   10 -10.0  -5.5   15.9  60.5   -10.5     98  0.5
  6500    9.1  48.4   165   20   10   0.5   0.3   14.7  58.5   -11.6    102  0.5
  6250    9.4  48.9   160   21   11   5.3   2.9   14.3  57.7   -12.1     86  0.4
  6000    9.7  49.5   160   23   12   4.0   2.2   13.9  57.0   -12.5     69  0.4
  5750   10.0  50.0   155   20   10   4.6   2.5   13.5  56.2   -13.0     52  0.3
  5500   10.3  50.5   150   16    8   3.6   2.0   13.0  55.5   -13.4     36  0.2
  5250   10.6  51.1   145   13    7   6.9   3.8   12.6  54.7   -13.9     19  0.1
  5000   11.0  51.8   130   10    5  -5.4  -3.0   12.2  54.0   -14.3      2  0.0

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

           04/23/2017 at 0900 MDT          |       04/23/2017 at 1200 MDT
                                           |
K index... -2.9  LI... +5.2                | K index... +2.1  LI... +4.4
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 -65.2 -85.4  265  49 25  -1.6  -0.9 | -63.7 -82.7  265  45 23  -1.5  -0.8
 45000 -67.4 -89.3  260  61 31   3.6   2.0 | -65.9 -86.6  255  64 33   2.3   1.3
 40000 -62.7 -80.9  250  63 33   3.2   1.8 | -62.7 -80.9  245  74 38   2.2   1.2
 38000 -59.0 -74.2  250  63 33   7.4   4.0 | -59.3 -74.7  245  74 38   7.2   4.0
 36000 -54.6 -66.3  250  63 32   7.4   4.0 | -54.9 -66.8  245  71 37   7.2   4.0
 34000 -49.9 -57.8  250  62 32   8.5   4.6 | -50.3 -58.5  245  68 35   8.4   4.6
 32000 -44.8 -48.6  250  61 31   8.4   4.6 | -45.3 -49.5  245  64 33   8.4   4.6
 30000 -39.3 -38.7  250  59 30   8.0   4.4 | -39.7 -39.5  245  59 31   8.1   4.5
 29000 -36.9 -34.4  250  57 29   8.0   4.4 | -37.3 -35.1  245  58 30   8.1   4.5
 28000 -34.5 -30.1  250  55 28   8.0   4.4 | -34.8 -30.6  245  56 29   8.1   4.5
 27000 -32.1 -25.8  250  53 27   7.9   4.3 | -32.5 -26.5  245  54 28   7.4   4.0
 26000 -29.7 -21.5  250  49 25   7.9   4.3 | -30.3 -22.5  245  50 26   7.4   4.1
 25000 -27.3 -17.1  255  46 24   7.9   4.3 | -28.1 -18.6  245  46 23   7.4   4.1
 24000 -25.0 -13.0  255  43 22   7.8   4.3 | -25.8 -14.4  250  42 22   8.6   4.7
 23000 -22.6  -8.7  255  40 21   7.8   4.3 | -23.2  -9.8  250  40 21   8.5   4.7
 22000 -20.3  -4.5  255  38 19   7.9   4.3 | -20.6  -5.1  250  39 20   8.5   4.7
 21000 -17.9  -0.2  255  36 18   8.0   4.4 | -18.1  -0.6  250  37 19   8.2   4.5
 20000 -15.5   4.1  255  35 18   8.0   4.4 | -15.7   3.7  250  36 19   8.2   4.5
 19500 -14.3   6.3  255  35 18   8.0   4.4 | -14.4   6.1  250  35 18   8.2   4.5
 19000 -13.1   8.4  255  35 18   8.0   4.4 | -13.2   8.2  250  35 18   8.3   4.6
 18500 -12.0  10.4  255  34 18   7.4   4.1 | -12.0  10.4  250  34 18   7.4   4.0
 18000 -10.8  12.6  255  34 18   7.5   4.1 | -10.9  12.4  250  33 17   7.4   4.1
 17500  -9.7  14.5  255  34 17   7.3   4.0 |  -9.8  14.4  250  33 17   7.3   4.0
 17000  -8.6  16.5  255  33 17   7.2   3.9 |  -8.8  16.2  245  32 16   7.1   3.9
 16500  -7.6  18.3  255  33 17   7.2   3.9 |  -7.7  18.1  245  31 16   7.1   3.9
 16000  -6.6  20.1  255  32 17   6.8   3.7 |  -6.7  19.9  245  31 16   6.3   3.5
 15500  -5.5  22.1  255  32 16   6.9   3.8 |  -5.8  21.6  245  31 16   6.4   3.5
 15000  -4.6  23.7  255  31 16   6.0   3.3 |  -4.8  23.4  245  31 16   5.9   3.2
 14500  -3.3  26.1  250  31 16   6.0   3.3 |  -3.6  25.5  245  31 16   5.9   3.2
 14000  -2.5  27.5  250  31 16   5.6   3.0 |  -2.8  27.0  245  31 16   5.7   3.1
 13500  -1.7  28.9  250  30 16   5.7   3.1 |  -2.0  28.4  245  32 16   5.7   3.1
 13000  -0.9  30.4  250  30 15   5.6   3.1 |  -1.1  30.0  240  32 17   7.5   4.1
 12500  -0.1  31.8  245  28 14   5.5   3.0 |  -0.0  32.0  240  31 16   7.5   4.1
 12000   0.7  33.3  245  26 13   7.0   3.8 |   1.1  34.0  235  30 16   8.0   4.4
 11500   1.8  35.2  240  23 12   7.2   3.9 |   2.3  36.1  235  28 14   8.2   4.5
 11000   2.8  37.0  235  21 11   5.5   3.0 |   3.4  38.1  230  25 13   5.5   3.0
 10500   3.7  38.7  230  19 10   4.7   2.6 |   4.2  39.6  225  21 11   4.6   2.5
 10250   4.1  39.4  225  18  9   8.0   4.4 |   4.5  40.1  220  19 10   7.2   4.0
 10000   4.8  40.6  225  18  9   8.4   4.6 |   5.2  41.4  215  18  9   7.7   4.2
  9750   5.3  41.5  225  18  9   5.4   3.0 |   5.6  42.1  215  18  9   5.3   2.9
  9500   5.7  42.3  220  18  9   6.4   3.5 |   6.0  42.8  215  17  9   5.9   3.3
  9250   6.2  43.2  220  19 10   5.4   2.9 |   6.4  43.5  215  16  8   5.8   3.2
  9000   6.5  43.7  220  19 10   5.1   2.8 |   6.8  44.2  215  15  8   6.9   3.8
  8750   6.9  44.4  220  19 10   5.7   3.1 |   7.4  45.3  210  13  7   7.7   4.2
  8500   7.4  45.3  220  19 10   5.5   3.0 |   7.9  46.2  210  12  6   7.1   3.9
  8250   7.8  46.0  215  19 10   5.4   3.0 |   8.5  47.3  205  11  6   9.1   5.0
  8000   8.1  46.6  215  19 10   4.7   2.6 |   9.3  48.7  205  11  5  10.2   5.6
  7750   8.4  47.1  210  18  9   4.2   2.3 |  10.0  50.0  210  10  5   9.2   5.0
  7500   8.7  47.7  205  17  9   3.5   1.9 |  10.7  51.3  210  10  5   9.6   5.3
  7250   8.9  48.0  200  17  9   2.2   1.2 |  11.4  52.5  210  10  5  10.3   5.7
  7000   9.1  48.4  195  16  8   1.8   1.0 |  12.2  54.0  210  10  5  10.5   5.7
  6750   9.2  48.6  185  15  8   1.4   0.8 |  13.0  55.4  210   9  5   9.7   5.3
  6500   9.3  48.7  180  14  7   2.6   1.4 |  13.7  56.7  210   9  5  10.5   5.8
  6250   9.6  49.3  175  11  6   3.7   2.0 |  14.6  58.3  215   9  5  11.7   6.4
  6000   9.8  49.6  170   9  5   3.7   2.0 |  15.4  59.7  215   9  4  11.3   6.2
  5750  10.2  50.4  165   7  4   7.3   4.0 |  16.3  61.3  215   8  4  12.2   6.7
  5500  10.9  51.6  160   7  3  10.6   5.8 |  17.3  63.1  215   8  4  15.0   8.2
  5250  11.6  52.9  160   6  3   9.5   5.2 |  18.5  65.3  215   8  4  17.0   9.4
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/23/2017 at 1500 MDT          |       04/23/2017 at 1800 MDT
                                           |
K index... +25.5  LI... +0.8               | K index... +24.2  LI... -1.0
CAPE... +16.2  CIN... -45.7                | CAPE... +76.7  CIN... -18.0
                                           |
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 -62.8 -81.0  255  44 23  -0.7  -0.4 | -61.0 -77.8  260  47 24   0.1   0.0
 45000 -63.8 -82.8  255  63 32   0.7   0.4 | -60.9 -77.6  260  64 33  -0.9  -0.5
 40000 -62.7 -80.9  245  83 43   0.8   0.4 | -62.6 -80.7  245  91 47  -1.2  -0.7
 38000 -59.7 -75.5  245  83 43   7.1   3.9 | -60.1 -76.2  240  93 48   7.3   4.0
 36000 -55.4 -67.7  240  79 41   7.1   3.9 | -55.7 -68.3  240  88 45   7.3   4.0
 34000 -50.9 -59.6  240  73 37   8.3   4.5 | -51.3 -60.3  235  84 43   7.8   4.3
 32000 -45.9 -50.6  240  61 32   8.3   4.6 | -46.6 -51.9  235  78 40   7.8   4.3
 30000 -40.2 -40.4  245  54 28   8.7   4.8 | -41.9 -43.4  235  73 37   7.6   4.2
 29000 -37.6 -35.7  245  55 28   8.7   4.8 | -39.1 -38.4  240  70 36   7.6   4.2
 28000 -35.0 -31.0  245  56 29   8.7   4.8 | -36.8 -34.2  240  68 35   7.6   4.2
 27000 -32.7 -26.9  245  55 29   6.6   3.6 | -34.5 -30.1  245  65 34   7.7   4.2
 26000 -30.7 -23.3  240  53 27   6.7   3.7 | -32.2 -26.0  245  61 32   7.7   4.2
 25000 -28.7 -19.7  240  51 26   6.7   3.7 | -29.9 -21.8  245  57 29   7.7   4.2
 24000 -26.5 -15.7  235  49 25   8.8   4.8 | -27.6 -17.7  245  53 27   7.8   4.3
 23000 -23.9 -11.0  235  47 24   8.8   4.8 | -25.2 -13.4  245  51 26   7.9   4.3
 22000 -21.2  -6.2  240  46 24   8.8   4.8 | -22.9  -9.2  245  48 25   7.9   4.3
 21000 -18.6  -1.5  240  45 23   7.8   4.3 | -20.6  -5.1  245  47 24   7.0   3.9
 20000 -16.3   2.7  240  43 22   7.9   4.3 | -18.5  -1.3  245  47 24   7.2   3.9
 19500 -15.1   4.8  240  43 22   7.9   4.3 | -17.4   0.7  245  47 24   7.2   3.9
 19000 -14.0   6.8  240  42 22   8.0   4.4 | -16.4   2.5  245  47 24   7.1   3.9
 18500 -12.9   8.8  240  41 21   6.6   3.6 | -15.3   4.5  245  47 24   7.9   4.3
 18000 -11.9  10.6  240  40 21   6.6   3.6 | -14.1   6.6  240  45 23   8.1   4.4
 17500 -11.0  12.2  240  40 20   6.2   3.4 | -13.0   8.6  240  43 22   8.3   4.6
 17000 -10.1  13.8  235  39 20   5.6   3.1 | -11.7  10.9  240  41 21   8.8   4.8
 16500  -9.4  15.1  235  38 19   5.6   3.1 | -10.4  13.3  240  39 20   8.7   4.8
 16000  -8.5  16.7  235  36 19   6.7   3.7 |  -9.1  15.6  240  38 19   9.4   5.1
 15500  -7.6  18.3  230  35 18   6.7   3.7 |  -7.8  18.0  235  36 19   9.3   5.1
 15000  -6.6  20.1  230  33 17   8.0   4.4 |  -6.4  20.5  235  35 18   9.4   5.2
 14500  -4.8  23.4  225  30 16   8.2   4.5 |  -5.0  23.0  230  33 17   9.4   5.2
 14000  -3.5  25.7  225  29 15   9.4   5.1 |  -2.9  26.8  230  30 16   9.5   5.2
 13500  -2.1  28.2  220  28 14   9.3   5.1 |  -1.5  29.3  225  29 15   9.5   5.2
 13000  -0.7  30.7  220  27 14   9.1   5.0 |  -0.1  31.8  225  28 15   9.4   5.1
 12500   0.6  33.1  220  26 13   9.1   5.0 |   1.3  34.3  225  27 14   9.3   5.1
 12000   2.0  35.6  220  25 13   9.0   5.0 |   2.7  36.9  220  26 13   9.1   5.0
 11500   3.3  37.9  220  23 12   9.1   5.0 |   4.0  39.2  220  25 13   9.1   5.0
 11000   4.6  40.3  220  22 11   8.3   4.6 |   5.4  41.7  220  24 12   8.6   4.7
 10500   5.8  42.4  220  20 10   8.3   4.6 |   6.6  43.9  220  22 11   8.6   4.7
 10250   6.5  43.7  220  19 10  10.1   5.5 |   7.3  45.1  220  21 11  10.3   5.6
 10000   7.3  45.1  220  19 10  10.0   5.5 |   8.1  46.6  220  21 11  10.0   5.5
  9750   8.0  46.4  225  18  9   8.8   4.8 |   8.8  47.8  220  20 10   8.8   4.8
  9500   8.7  47.7  225  17  9   9.2   5.1 |   9.5  49.1  220  19 10   9.3   5.1
  9250   9.3  48.7  225  16  8   8.8   4.8 |  10.1  50.2  220  17  9   8.5   4.7
  9000  10.0  50.0  225  16  8   9.3   5.1 |  10.8  51.4  220  17  9   8.6   4.7
  8750  10.7  51.3  230  16  8  10.1   5.6 |  11.4  52.5  225  16  8   9.5   5.2
  8500  11.5  52.7  230  15  8   9.7   5.3 |  12.1  53.8  225  15  8   8.9   4.9
  8250  12.2  54.0  230  15  8  10.6   5.8 |  12.8  55.0  225  14  7  10.1   5.6
  8000  13.0  55.4  230  15  8  10.3   5.7 |  13.6  56.5  230  13  7  10.2   5.6
  7750  13.7  56.7  235  14  7   9.2   5.1 |  14.3  57.7  230  13  7   9.2   5.0
  7500  14.4  57.9  235  14  7   9.4   5.2 |  15.0  59.0  230  12  6   9.2   5.1
  7250  15.2  59.4  235  14  7  10.0   5.5 |  15.7  60.3  230  12  6  10.1   5.5
  7000  15.9  60.6  235  14  7  10.3   5.7 |  16.5  61.7  230  12  6  10.5   5.8
  6750  16.7  62.1  235  14  7   9.7   5.3 |  17.3  63.1  230  11  6   9.7   5.3
  6500  17.4  63.3  235  13  7  10.1   5.5 |  18.0  64.4  230  11  6   9.7   5.3
  6250  18.2  64.8  240  13  7  10.9   6.0 |  18.7  65.7  235  11  5   9.8   5.4
  6000  19.0  66.2  240  13  6  11.4   6.3 |  19.4  66.9  235  10  5   9.7   5.3
  5750  19.9  67.8  240  12  6  11.3   6.2 |  20.1  68.2  235  10  5   9.4   5.1
  5500  20.8  69.4  240  11  6  13.4   7.3 |  20.8  69.4  235   9  4   9.1   5.0
  5250  21.9  71.4  240  12  6  17.7   9.7 |  21.5  70.7  235   9  5   9.0   4.9
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

This product is issued twice per day, once by approximately 0630 MST/0730 MDT
(1330 UTC) and again by approximately 1830 MST/1930 MDT (0130 UTC).  It is not
continuously monitored nor updated after its initial issuance.

The information contained herein is based on rawinsonde observation and/or
numerical weather prediction model data taken at Walker Field in Grand
Junction, Colorado at

                   North Latitude:  39 deg 07 min 00.001 sec
                   West Longitude: 108 deg 31 min 59.998 sec
                   Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado.  Note that some elevations in numerical weather prediction models
differ from actual station elevations, which can lead to data which appear
to be below ground.  Erroneous data such as these should not be used.

The content and format of this report as well as the issuance times are subject
to change without prior notice.  Comments and suggestions are welcome and should
be directed to one of the addresses or phone numbers shown at the bottom of this
page.  To expedite a response to comments, be sure to mention your interest in
the soaring forecast.

DEFINITIONS:

CAPE (Convective Available Potential Energy) - An integrated measure of the
     energy available for convective development, also known as the positive
     area on a thermodynamic diagram.  Units are Joules per kilogram.  Larger
     values are indicative of greater instability and the possibility of
     stronger convective activity, including thunderstorms.  Values around or
     greater than 1000 suggest the possibility of severe weather should
     convective activity develop.

CIN (Convective Inhibition) - An integrated measure of the amount of energy
     needed to initiate convective activity, also known as the negative area on
     a thermodynamic diagram.  Units are Joules per kilogram.  The more negative
     this number, the more energy is required to initiate convection.  This
     inhibitive energy can be overcome through surface heating, cooling aloft,
     lifting mechanisms (orographic, frontal, gravity waves, etc.)

Convective Condensation Level - The height to which an air parcel possessing the
     average saturation mixing ratio in the lowest 4000 feet of the airmass,
     if heated sufficiently from below, will rise dry adiabatically until it
     just becomes saturated.  It estimates the base of cumulus clouds that are
     produced by surface heating only.

Convection Temperature (ConvectionT) - The surface temperature required to make
     the airmass dry adiabatic up to the given level.  It can be considered a
     "trigger temperature" for that level.

Freezing Level - The height where the temperature is zero degrees Celsius.

Height of Stable Layer - The height (between 12,000 and 18,000 feet above
     mean sea level) where the smallest lapse rate exists.  The location and
     existence of this feature is important in the generation of mountain
     waves.

K Index - A measure of stability which combines the temperature difference
     between approximately 5,000 and 18,000 feet above the surface, the amount
     of moisture at approximately 5,000 feet above the surface, and a measure
     of the dryness at approximately 10,000 feet above the surface.  Larger
     positive numbers indicate more instability and a greater likelihood of
     thunderstorm development.  One interpretation of K index values regarding
     soaring in the western United States is given in WMO Technical Note 158
     and is reproduced in the following table:

          below -10    no or weak thermals
           -10 to 5    dry thermals or 1/8 cumulus with moderate thermals
            5 to 15    good soaring conditions
           15 to 20    good soaring conditions with occasional showers
           20 to 30    excellent soaring conditions, but increasing
                       probability of showers and thunderstorms
           above 30    more than 60 percent probability of thunderstorms

Lapse Rate - The change with height of the temperature. Negative values indicate
     inversions.

Lifted Condensation Level - The height to which an air parcel possessing the
     average dew point in the lowest 4000 feet of the airmass and the forecast
     maximum temperature must be lifted dry adiabatically to attain saturation.

Lifted Index (LI) - The difference between the environmental temperature at a
     level approximately 18,000 feet above the surface and the temperature of
     an air parcel lifted dry adiabatically from the surface to its lifted
     condensation level and then pseudoadiabatically thereafter to this same
     level.  The parcel`s initial temperature is the forecast maximum
     temperature and its dew point is the average dew point in the lowest 4000
     feet of the airmass.  Negative values are indicative of instability with
     positive values showing stable conditions.

Lift Rate - An experimental estimate of the strength of thermals.  It is
     computed the same way as the maximum rate of lift but uses the actual
     level rather than the maximum height of thermals in the calculation.
     Also, none of the empirical adjustments based on cloudiness and K-index
     are applied to these calculations.

Maximum Height of Thermals - The height where the dry adiabat through the
     forecast maximum temperature intersects the environmental temperature.

Maximum Rate of Lift - An estimate of the maximum strength of thermals.  It
     is computed from an empirical formula which combines the expected maximum
     height of thermals with the difference in the environmental temperatures
     between the maximum height of thermals and the temperature 4,000 feet
     above the ground.  After this computation, further empirical adjustments
     are made based on the value of the K-index and the amount and opacity of
     middle and high level cloudiness expected between the time of trigger
     temperature and the time of overdevelopment.

Middle/High Clouds - The amount and opacity of middle (altostratus, altocumulus)
     or high (cirrus, cirrostratus, cirrocumulus) clouds.  Broken means that
     between 60% and 90% of the sky is covered by the cloud, with overcast
     conditions occurring when more than 90% of the sky is covered by the cloud.
     Thin implies that the clouds are predominantly transparent, meaning that
     some sunlight is reaching the ground, in contrast to opaque which suggests
     that little sunlight is reaching the ground.

Potential Height of Wave - The minimum of the following two heights:
     1. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind direction changes by 30 degrees or more
     2. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind speed no longer increases with height

PVA/NVA - Positive vorticity advection (PVA)/negative vorticity advection (NVA)
     on the 500 millibar isobaric surface (approximately 18,000 feet above mean
     sea level).  Weak PVA has been shown to assist in mountain wave soaring.

Soaring Window - The time between the time the trigger temperature is reached
                 and the time of overdevelopment.

Thermal Index - The difference between the environmental temperature and the
     temperature at a particular level determined by following the dry adiabat
     through the forecast maximum temperature up to that level.  Negative values
     are indicative of thermal lift.

Thermal Soaring Index - An adjective rating (for sailplanes) based on the
     computed maximum rate of lift, and the wind speed and middle and high
     cloud cover expected during the soaring window (the time of the trigger
     temperature and the time of overdevelopment) according to the following:

                 Maximum rate of lift        Adjective Rating
                      >= 800 fpm                 Excellent
                 >= 400 and < 800 fpm              Good
                 >= 200 and < 400 fpm              Fair
                       < 200 fpm                   Poor

Time of Overdevelopment - The time one or more of the following phenomena,
     which essentially shut off thermal lift, is expected to occur:
     1. formation of broken to overcast convective cloud cover
     2. formation of scattered to numerous downbursts
     3. initiation of widespread precipitation

Time of Trigger Temperature - The time the surface temperature is expected to
     reach the trigger temperature.

Trigger Temperature - The surface temperature required to make the first 4000
     feet of the atmosphere dry adiabatic.

Wave Soaring Index - An empirical, adjective rating (for sailplanes) which
     attempts to combine a variety of phenomena important in mountain wave
     soaring into a single index number.  Objective points are assigned to
     these phenomena: wind speed and direction at 14,000 ft MSL, the static
     stability in the 12,000-18,000 ft MSL layer, the wind speed gradient above
     the stable layer, jet stream location and frontal and upper trough
     movements.

042613



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