Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 131302
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0702 MDT Sunday, August 13, 2017

This forecast is for Sunday, August 13, 2017:

If the trigger temperature of 79.4 F/26.3 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1116 ft/min (5.7 m/s)
   Maximum height of thermals.................. 15560 ft MSL (10721 ft AGL)

Forecast maximum temperature................... 89.0 F/32.1 C
Time of trigger temperature.................... 1200 MDT
Time of overdevelopment........................ 1500 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 11207 ft MSL (6368 ft AGL)
Thermal soaring outlook for Monday 08/14....... Good

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

Remarks...

Sunrise/Sunset.................... 06:25:48 / 20:12:29 MDT
Total possible sunshine........... 13 hr 46 min 41 sec (826 min 41 sec)
Altitude of sun at 13:18:49 MDT... 65.29 degrees

Upper air data from rawinsonde observation taken on 08/13/2017 at 0600 MDT

Freezing level.................. 15278 ft MSL (10439 ft AGL)
Convective condensation level... 14349 ft MSL (9510 ft AGL)
Lifted condensation level....... 14852 ft MSL (10013 ft AGL)
Lifted index.................... -4.5
K index......................... +25.1

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  -60.3 -76.5   290   39   20   3.8   2.1   94.1 201.5    36.2      M    M
 45000  -57.1 -70.8   260   74   38   7.0   3.9   74.9 166.8    26.8      M    M
 40000  -50.7 -59.3   265   80   41   0.5   0.2   62.1 143.8    20.2      M    M
 38000  -50.5 -58.9   270   63   32   0.7   0.4   53.7 128.6    15.0      M    M
 36000  -46.4 -51.5   275   50   26   7.8   4.3   50.1 122.1    12.9      M    M
 34000  -42.0 -43.6   275   45   23   7.7   4.2   47.9 118.2    11.7      M    M
 32000  -37.4 -35.3   280   41   21   7.9   4.3   46.3 115.4    10.8      M    M
 30000  -33.1 -27.6   280   28   14   9.3   5.1   44.3 111.8     9.5      M    M
 29000  -30.5 -22.9   280   24   13   7.0   3.8   43.9 111.1     9.3      M    M
 28000  -28.2 -18.8   280   21   11   8.3   4.5   43.1 109.6     8.8      M    M
 27000  -25.8 -14.4   290   20   10   8.3   4.6   42.5 108.4     8.4      M    M
 26000  -23.5 -10.3   305   19   10   4.5   2.5   41.7 107.0     7.8      M    M
 25000  -22.1  -7.8   305   16    8   8.7   4.8   39.8 103.7     6.4      M    M
 24000  -20.0  -4.0   310   15    8   7.6   4.1   38.8 101.9     5.6      M    M
 23000  -17.5   0.5   315   16    8   8.7   4.8   38.3 101.0     5.2      M    M
 22000  -15.5   4.1   310   13    7   6.5   3.6   37.3  99.1     4.3      M    M
 21000  -13.6   7.5   300    9    5   6.7   3.7   36.1  97.0     3.4      M    M
 20000  -11.4  11.5   285    6    3   7.7   4.2   35.3  95.6     2.7      M    M
 19500   -9.6  14.7   295    5    3   8.0   4.4   34.8  94.6     2.3      M    M
 19000   -8.3  17.1   300    5    2   9.0   4.9   34.6  94.2     2.1      M    M
 18500   -6.9  19.6   305    4    2   9.0   4.9   34.4  94.0     2.1      M    M
 18000   -5.6  21.9   310    4    2   6.7   3.7   34.3  93.7     1.9      M    M
 17500   -4.8  23.4   315    4    2   7.3   4.0   33.6  92.5     1.2      M    M
 17000   -3.7  25.3   320    3    2   7.6   4.2   33.3  91.9     0.9      M    M
 16500   -2.6  27.3   330    3    2   7.7   4.2   32.9  91.3     0.6      M    M
 16000   -1.5  29.3   335    3    1   7.7   4.2   32.6  90.7     0.3      M    M
 15500   -0.4  31.3   350    2    1   7.7   4.2   32.3  90.1    -0.1    904  4.6
 15000    0.8  33.4   355    3    1   7.7   4.2   31.9  89.5    -0.4    856  4.3
 14500    1.9  35.4   320    9    5   7.7   4.2   31.6  88.8    -0.8    807  4.1
 14000    3.0  37.4   315   16    8   7.7   4.2   31.2  88.2    -1.1    759  3.9
 13500    4.1  39.4   310   14    7   7.2   4.0   30.8  87.5    -1.5    712  3.6
 13000    5.1  41.2   305   13    7   7.2   3.9   30.4  86.7    -2.0    668  3.4
 12500    6.0  42.8   300   11    6   7.3   4.0   30.0  86.0    -2.5    623  3.2
 12000    7.2  45.0   295   10    5   8.9   4.9   29.8  85.6    -2.8    572  2.9
 11500    8.6  47.5   275    8    4   8.8   4.8   29.6  85.2    -2.9    518  2.6
 11000    9.9  49.8   245    7    4   9.1   5.0   29.4  85.0    -3.1    463  2.3
 10500   11.0  51.8   220    8    4   5.6   3.1   29.1  84.4    -3.4    415  2.1
 10250   11.4  52.5   215    9    5   6.4   3.5   28.8  83.8    -3.8    396  2.0
 10000   11.9  53.4   210    9    5   7.0   3.9   28.5  83.4    -4.0    373  1.9
  9750   12.4  54.3   205    9    5   6.9   3.8   28.3  83.0    -4.2    351  1.8
  9500   12.9  55.2   200    9    5   6.9   3.8   28.1  82.6    -4.5    328  1.7
  9250   13.4  56.1   195   10    5   6.9   3.8   27.9  82.2    -4.7    305  1.6
  9000   13.9  57.0   190   10    5   6.8   3.7   27.7  81.8    -4.9    283  1.4
  8750   14.5  58.1   185   10    5   7.3   4.0   27.4  81.4    -5.2    260  1.3
  8500   15.0  59.0   175   10    5   5.5   3.0   27.2  81.0    -5.4    237  1.2
  8250   15.1  59.2   165   10    5   0.4   0.2   26.7  80.1    -5.9    224  1.1
  8000   15.1  59.2   155   10    5   0.5   0.3   25.9  78.6    -6.8    220  1.1
  7750   15.3  59.5   155   11    5   6.2   3.4   25.4  77.7    -7.3    206  1.0
  7500   15.8  60.4   155   11    6   8.6   4.7   25.3  77.5    -7.5    182  0.9
  7250   16.4  61.5   155   12    6   7.2   3.9   25.1  77.2    -7.7    157  0.8
  7000   17.0  62.6   155   13    7  10.6   5.8   25.0  77.0    -7.8    132  0.7
  6750   17.6  63.7   155   15    8  -1.5  -0.8   24.9  76.8    -8.0    107  0.5
  6500   16.9  62.4   155   17    9  -6.4  -3.5   23.5  74.2    -9.5    121  0.6
  6250   17.0  62.6   155   19   10   7.0   3.8   22.9  73.2   -10.1    111  0.6
  6000   17.5  63.5   155   21   11   7.3   4.0   22.7  72.9   -10.3     87  0.4
  5750   17.9  64.2   150   19   10   3.8   2.1   22.4  72.3   -10.7     69  0.3
  5500   18.0  64.4   145   16    8   2.5   1.4   21.9  71.4   -11.3     57  0.3
  5250   18.2  64.8   130   12    6   3.0   1.6   21.3  70.4   -11.9     45  0.2
  5000   18.3  64.9   115   10    5   2.6   1.4   20.8  69.5   -12.6     33  0.2

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

           08/13/2017 at 0900 MDT          |       08/13/2017 at 1200 MDT
                                           |
K index... +30.3  LI... -2.1               | K index... +27.4  LI... -3.3
CAPE... +428.8  CIN... -70.2               | CAPE... +750.9  CIN... -27.9
                                           |
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 -61.0 -77.8  275  45 23   3.2   1.7 | -60.5 -76.9  270  43 22   2.8   1.6
 45000 -56.1 -69.0  270  64 33   3.4   1.8 | -56.6 -69.9  275  57 29   2.1   1.2
 40000 -51.1 -60.0  275  67 34   2.9   1.6 | -52.9 -63.2  280  48 25   4.6   2.5
 38000 -49.4 -56.9  275  52 27   2.9   1.6 | -50.1 -58.2  280  39 20   4.6   2.5
 36000 -47.6 -53.7  280  37 19   3.1   1.7 | -47.3 -53.1  285  29 15   4.3   2.4
 34000 -42.8 -45.0  280  28 14   8.5   4.7 | -42.6 -44.7  285  25 13   8.7   4.8
 32000 -37.6 -35.7  285  22 11   8.4   4.6 | -37.4 -35.3  285  22 11   8.5   4.7
 30000 -32.6 -26.7  290  22 11   8.4   4.6 | -32.5 -26.5  285  20 10   8.1   4.4
 29000 -30.0 -22.0  290  22 11   8.4   4.6 | -30.1 -22.2  280  19 10   8.1   4.4
 28000 -27.5 -17.5  290  23 12   8.2   4.5 | -27.7 -17.9  280  18  9   8.0   4.4
 27000 -25.2 -13.4  295  23 12   7.9   4.3 | -25.4 -13.7  285  17  9   7.5   4.1
 26000 -22.8  -9.0  295  24 12   7.9   4.3 | -22.6  -8.7  290  16  8   7.5   4.1
 25000 -20.4  -4.7  300  25 13   8.1   4.4 | -20.4  -4.7  295  16  8   7.4   4.1
 24000 -18.4  -1.1  300  24 13   6.6   3.6 | -18.3  -0.9  300  16  8   7.1   3.9
 23000 -16.5   2.3  295  24 12   6.7   3.7 | -16.2   2.8  300  17  9   7.1   3.9
 22000 -14.6   5.7  295  23 12   6.8   3.7 | -14.1   6.6  305  18  9   6.9   3.8
 21000 -12.7   9.1  300  21 11   6.5   3.6 | -12.2  10.0  305  17  9   6.4   3.5
 20000 -10.8  12.6  305  20 10   6.5   3.6 | -10.3  13.5  310  15  8   6.4   3.5
 19500  -9.8  14.4  310  19 10   6.6   3.6 |  -9.4  15.1  310  14  7   6.4   3.5
 19000  -8.9  16.0  315  18 10   6.4   3.5 |  -8.4  16.9  310  13  7   6.7   3.7
 18500  -8.0  17.6  315  17  9   6.4   3.5 |  -7.5  18.5  315  12  6   6.7   3.7
 18000  -7.0  19.4  320  16  8   6.3   3.5 |  -6.5  20.3  320  11  6   6.8   3.7
 17500  -6.2  20.8  320  15  8   5.6   3.1 |  -5.5  22.1  325  10  5   7.0   3.8
 17000  -5.4  22.3  325  14  7   5.6   3.1 |  -4.5  23.9  335   8  4   7.1   3.9
 16500  -4.6  23.7  325  13  7   6.0   3.3 |  -3.5  25.7  340   7  4   7.1   3.9
 16000  -3.7  25.3  325  12  6   6.1   3.4 |  -2.5  27.5  350   6  3   7.1   3.9
 15500  -2.4  27.7  330  12  6   6.9   3.8 |  -1.5  29.3  360   5  3   6.9   3.8
 15000  -1.4  29.5  330  12  6   6.9   3.8 |  -0.5  31.1  355   5  2   6.8   3.7
 14500  -0.4  31.3  330  12  6   7.0   3.9 |   0.5  32.9  355   4  2   6.8   3.7
 14000   0.7  33.3  325  11  6   7.1   3.9 |   1.4  34.5  340   4  2   6.5   3.6
 13500   1.7  35.1  325  11  6   7.9   4.3 |   2.4  36.3  325   4  2   6.6   3.6
 13000   3.0  37.4  325  11  6   8.5   4.7 |   4.0  39.2  305   6  3   8.1   4.4
 12500   4.2  39.6  320  11  6   8.7   4.8 |   5.2  41.4  300   7  4   8.0   4.4
 12000   5.5  41.9  320  11  6   8.9   4.9 |   6.3  43.3  290   9  4   7.9   4.4
 11500   6.9  44.4  320  10  5   8.6   4.7 |   7.4  45.3  285  10  5   8.0   4.4
 11000   8.1  46.6  320   9  5   7.5   4.1 |   8.5  47.3  280  11  6   7.8   4.3
 10500   9.2  48.6  320   7  4   3.7   2.0 |   9.7  49.5  275  12  6   3.9   2.2
 10250   9.4  48.9  320   7  3   4.4   2.4 |   9.8  49.6  275  11  6   4.5   2.5
 10000  10.0  50.0  325   5  3  10.0   5.5 |  10.5  50.9  275  11  6  10.1   5.5
  9750  10.7  51.3  330   4  2   9.0   4.9 |  11.2  52.2  275  10  5   9.0   4.9
  9500  11.3  52.3  335   3  1   7.5   4.1 |  11.8  53.2  275  10  5   7.8   4.3
  9250  11.7  53.1  360   2  1   5.6   3.1 |  12.3  54.1  275   9  5   6.6   3.6
  9000  12.2  54.0  055   1  1   6.9   3.8 |  12.9  55.2  270   8  4   7.6   4.2
  8750  12.7  54.9  100   2  1   7.6   4.2 |  13.5  56.3  260   7  4   7.7   4.2
  8500  13.2  55.8  115   3  2   6.6   3.6 |  14.0  57.2  255   7  3   7.3   4.0
  8250  13.6  56.5  120   4  2   6.1   3.4 |  14.5  58.1  245   6  3   7.1   3.9
  8000  14.0  57.2  125   5  3   5.6   3.1 |  15.1  59.2  235   6  3   7.1   3.9
  7750  14.3  57.7  130   6  3   4.7   2.6 |  15.6  60.1  230   7  3   7.5   4.1
  7500  14.6  58.3  135   7  4   4.6   2.5 |  16.1  61.0  225   7  4   8.8   4.8
  7250  14.9  58.8  140   8  4   4.2   2.3 |  16.7  62.1  225   7  4   9.6   5.3
  7000  15.1  59.2  145   8  4   4.7   2.6 |  17.3  63.1  220   7  4   9.2   5.0
  6750  15.4  59.7  150   9  5   4.8   2.7 |  17.9  64.2  220   7  4  10.2   5.6
  6500  15.8  60.4  155   9  4   4.4   2.4 |  18.7  65.7  220   7  4  11.4   6.2
  6250  16.1  61.0  160   8  4   4.6   2.5 |  19.6  67.3  220   7  3  11.8   6.5
  6000  16.4  61.5  165   8  4   3.7   2.0 |  20.4  68.7  220   7  3  10.2   5.6
  5750  16.7  62.1  165   7  4   6.8   3.7 |  21.1  70.0  220   6  3  11.1   6.1
  5500  17.4  63.3  165   7  4  10.7   5.8 |  22.1  71.8  225   6  3  14.0   7.7
  5250  18.1  64.6  165   7  4   7.7   4.2 |  23.1  73.6  225   6  3  11.7   6.4
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           08/13/2017 at 1500 MDT          |       08/13/2017 at 1800 MDT
                                           |
K index... +20.1  LI... -2.2               | K index... +16.2  LI... -1.8
CAPE... +552.7  CIN... -34.4               | CAPE... +123.7  CIN... -80.7
                                           |
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 -61.1 -78.0  270  44 23   2.2   1.2 | -61.9 -79.4  275  41 21   2.0   1.1
 45000 -57.9 -72.2  275  51 26   1.9   1.0 | -59.2 -74.6  285  40 21   1.4   0.7
 40000 -54.3 -65.7  295  32 16   5.7   3.1 | -56.4 -69.5  330  22 11   8.4   4.6
 38000 -50.8 -59.4  295  27 14   5.8   3.2 | -51.5 -60.7  325  19 10   8.2   4.5
 36000 -47.3 -53.1  300  23 12   5.6   3.1 | -46.6 -51.9  320  17  9   8.2   4.5
 34000 -42.5 -44.5  300  23 12   8.5   4.7 | -41.9 -43.4  310  16  8   7.7   4.2
 32000 -37.4 -35.3  300  25 13   8.5   4.7 | -36.6 -33.9  295  18  9   7.6   4.2
 30000 -32.3 -26.1  300  25 13   8.5   4.7 | -31.8 -25.2  290  20 10   8.1   4.4
 29000 -29.7 -21.5  300  25 13   8.5   4.7 | -29.4 -20.9  290  21 11   8.1   4.4
 28000 -27.2 -17.0  300  25 13   8.3   4.6 | -27.0 -16.6  290  22 11   8.0   4.4
 27000 -24.8 -12.6  295  24 12   7.8   4.3 | -24.6 -12.3  290  22 12   8.0   4.4
 26000 -21.9  -7.4  295  23 12   7.8   4.3 | -22.2  -8.0  285  23 12   8.0   4.4
 25000 -19.6  -3.3  295  22 11   7.6   4.2 | -19.8  -3.6  285  23 12   7.9   4.4
 24000 -17.5   0.5  295  20 10   7.1   3.9 | -17.6   0.3  285  22 11   7.3   4.0
 23000 -15.4   4.3  290  18  9   7.3   4.0 | -15.4   4.3  285  21 11   7.3   4.0
 22000 -13.3   8.1  290  17  9   7.1   3.9 | -13.2   8.2  290  20 11   7.0   3.8
 21000 -11.4  11.5  295  15  8   6.3   3.4 | -11.6  11.1  290  20 11   5.1   2.8
 20000  -9.6  14.7  305  13  7   6.3   3.4 | -10.1  13.8  290  21 11   5.4   2.9
 19500  -8.7  16.3  310  12  6   6.3   3.4 |  -9.4  15.1  290  21 11   5.4   2.9
 19000  -7.7  18.1  315  12  6   6.6   3.6 |  -8.5  16.7  290  20 10   8.2   4.5
 18500  -6.7  19.9  320  11  6   6.6   3.6 |  -7.2  19.0  295  18  9   8.3   4.5
 18000  -5.7  21.7  325  10  5   6.9   3.8 |  -6.0  21.2  295  17  9   8.3   4.6
 17500  -4.6  23.7  325  10  5   7.3   4.0 |  -4.7  23.5  300  15  8   8.3   4.6
 17000  -3.6  25.5  325   9  5   7.4   4.1 |  -3.5  25.7  300  14  7   8.3   4.6
 16500  -2.5  27.5  325   9  4   6.6   3.6 |  -2.3  27.9  305  13  7   8.2   4.5
 16000  -1.6  29.1  320   8  4   6.7   3.7 |  -1.0  30.2  305  13  7   8.2   4.5
 15500  -0.6  30.9  315   8  4   7.3   4.0 |   0.8  33.4  305  12  6   8.5   4.6
 15000   0.5  32.9  315   8  4   7.6   4.2 |   2.0  35.6  305  12  6   8.5   4.6
 14500   1.6  34.9  310   8  4   7.8   4.3 |   3.3  37.9  305  11  6   8.6   4.7
 14000   2.7  36.9  305   9  5   8.0   4.4 |   4.5  40.1  305  11  6   8.6   4.7
 13500   3.9  39.0  305  10  5   8.0   4.4 |   5.8  42.4  305  11  5   8.5   4.7
 13000   5.7  42.3  300  10  5   8.6   4.7 |   7.0  44.6  305  10  5   8.5   4.7
 12500   7.0  44.6  300  11  6   8.6   4.7 |   8.2  46.8  305  10  5   8.7   4.7
 12000   8.2  46.8  300  10  5   8.6   4.7 |   9.5  49.1  300  11  5   8.9   4.9
 11500   9.5  49.1  295  10  5   8.6   4.7 |  10.8  51.4  300  11  5   9.0   4.9
 11000  10.8  51.4  290   9  5   8.4   4.6 |  12.2  54.0  295  11  6   8.9   4.9
 10500  12.0  53.6  280   8  4   5.0   2.7 |  13.6  56.5  290  11  6   5.7   3.1
 10250  12.2  54.0  280   8  4   5.6   3.1 |  13.9  57.0  290  11  6   6.1   3.4
 10000  13.0  55.4  275   7  4  10.6   5.8 |  14.6  58.3  285  11  5  10.7   5.9
  9750  13.7  56.7  270   7  4   9.7   5.3 |  15.3  59.5  285  10  5   9.8   5.4
  9500  14.4  57.9  260   7  3   8.2   4.5 |  16.0  60.8  280  10  5   9.0   4.9
  9250  14.9  58.8  260   7  3   6.7   3.7 |  16.6  61.9  280  10  5   7.5   4.1
  9000  15.4  59.7  255   6  3   7.7   4.3 |  17.1  62.8  280   9  4   7.7   4.2
  8750  15.9  60.6  250   6  3   7.7   4.2 |  17.7  63.9  275   8  4   7.9   4.3
  8500  16.5  61.7  245   6  3   7.8   4.3 |  18.3  64.9  270   7  4   7.5   4.1
  8250  17.0  62.6  240   5  3   7.9   4.3 |  18.8  65.8  265   6  3   6.8   3.7
  8000  17.5  63.5  235   5  3   7.6   4.2 |  19.2  66.6  255   5  3   6.8   3.7
  7750  17.9  64.2  230   5  2   7.5   4.1 |  19.7  67.5  250   5  2   6.2   3.4
  7500  18.4  65.1  225   4  2   9.0   4.9 |  20.1  68.2  245   4  2   8.5   4.6
  7250  19.1  66.4  225   4  2  10.0   5.5 |  20.8  69.4  245   4  2  10.7   5.9
  7000  19.8  67.6  225   4  2   9.7   5.3 |  21.6  70.9  240   4  2   9.7   5.3
  6750  20.6  69.1  225   4  2  10.4   5.7 |  22.3  72.1  240   4  2   9.4   5.2
  6500  21.4  70.5  225   4  2  11.2   6.2 |  23.0  73.4  240   4  2  10.3   5.6
  6250  22.2  72.0  225   4  2  12.1   6.7 |  23.8  74.8  240   4  2  10.9   6.0
  6000  23.1  73.6  220   4  2   9.8   5.4 |  24.6  76.3  240   4  2  10.3   5.7
  5750  23.8  74.8  220   4  2  12.0   6.6 |  25.3  77.5  240   4  2   9.8   5.4
  5500  24.9  76.8  225   4  2  17.0   9.3 |  26.0  78.8  240   4  2   9.9   5.4
  5250  26.1  79.0  225   4  2  13.1   7.2 |  26.8  80.2  240   4  2  10.0   5.5
  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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