Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 181225
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0625 MDT Thursday, May 18, 2017

This forecast is for Thursday, May 18, 2017:

If the trigger temperature of 44.3 F/6.9 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 187 ft/min (1.0 m/s)
   Maximum height of thermals.................. 12299 ft MSL (7460 ft AGL)

Forecast maximum temperature................... 50.0 F/10.5 C
Time of trigger temperature.................... 1030 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................. 8845 ft MSL (4006 ft AGL)
Thermal soaring outlook for Friday 05/19....... Fair

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

Remarks...

Sunrise/Sunset.................... 05:58:27 / 20:22:33 MDT
Total possible sunshine........... 14 hr 24 min 6 sec (864 min 6 sec)
Altitude of sun at 13:10:41 MDT... 70.59 degrees

Upper air data from rawinsonde observation taken on 05/18/2017 at 0600 MDT

Freezing level.................. 6027 ft MSL (1188 ft AGL)
Convective condensation level... 8481 ft MSL (3642 ft AGL)
Lifted condensation level....... 9925 ft MSL (5085 ft AGL)
Lifted index.................... +1.1
K index......................... +18.2

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  -55.0 -67.0   300    9    5   5.2   2.8  109.6 229.3    56.8      M    M
 45000  -50.4 -58.7   240    1    1   7.1   3.9   92.6 198.7    50.3      M    M
 40000  -47.8 -54.0   230   25   13   3.3   1.8   73.5 164.3    41.3      M    M
 38000  -47.3 -53.1   210   24   12  -2.8  -1.5   64.3 147.8    36.4      M    M
 36000  -46.1 -51.0   190   15    8   4.0   2.2   57.4 135.3    32.6      M    M
 34000  -45.2 -49.4   185   24   13  -5.5  -3.0   50.3 122.6    28.4      M    M
 32000  -44.0 -47.2   205   24   12   2.9   1.6   43.9 111.0    24.5      M    M
 30000  -45.0 -49.0   175   30   15  -4.7  -2.6   34.5  94.0    18.1      M    M
 29000  -44.3 -47.7   155   33   17   4.5   2.5   31.5  88.6    16.1      M    M
 28000  -43.0 -45.4   145   38   20   4.3   2.4   29.4  84.9    14.8      M    M
 27000  -42.0 -43.6   145   37   19   1.9   1.1   26.7  80.1    12.9      M    M
 26000  -40.9 -41.6   140   36   19   6.9   3.8   24.4  75.9    11.2      M    M
 25000  -39.1 -38.4   140   35   18   3.1   1.7   22.9  73.3    10.2      M    M
 24000  -37.3 -35.1   135   30   16   9.0   4.9   21.5  70.8     9.2      M    M
 23000  -35.0 -31.0   140   28   14   7.8   4.3   20.8  69.4     8.7      M    M
 22000  -32.6 -26.7   155   23   12   8.1   4.4   20.2  68.3     8.3      M    M
 21000  -30.2 -22.4   155   21   11   8.1   4.4   19.5  67.1     7.8      M    M
 20000  -27.2 -17.0   150   19   10   7.9   4.3   18.7  65.7     7.3      M    M
 19500  -26.1 -15.0   150   20   10   7.9   4.3   18.4  65.1     7.0      M    M
 19000  -24.9 -12.8   150   21   11   7.9   4.3   18.1  64.5     6.8      M    M
 18500  -23.7 -10.7   165   19   10   7.9   4.3   17.7  63.9     6.5      M    M
 18000  -22.5  -8.5   175   19   10   7.9   4.3   17.4  63.3     6.2      M    M
 17500  -21.4  -6.5   180   18    9   7.9   4.3   17.0  62.7     6.0      M    M
 17000  -20.2  -4.4   185   17    9   7.0   3.8   16.7  62.1     5.7      M    M
 16500  -19.3  -2.7   185   14    7   5.6   3.1   16.1  61.9     5.2      M    M
 16000  -18.5  -1.3   185   11    5   5.6   3.1   15.4  59.7     4.6      M    M
 15500  -17.7   0.1   190    8    4   5.6   3.1   14.7  58.4     3.9      M    M
 15000  -16.8   1.8   200    6    3   5.6   3.1   14.0  57.1     3.3      M    M
 14500  -16.0   3.2   220    4    2   5.6   3.1   13.3  55.9     2.7      M    M
 14000  -15.2   4.6   265    3    2   5.6   3.1   12.7  54.8     2.2      M    M
 13500  -14.3   6.3   300    5    3   5.6   3.1   11.9  53.5     1.5      M    M
 13000  -13.5   7.7   310    9    4   5.6   3.1   11.2  52.2     0.8      M    M
 12500  -12.7   9.1   315   12    6   5.4   3.0   10.6  51.0     0.2      M    M
 12000  -11.7  10.9   320   15    8   9.1   5.0   10.1  50.2    -0.2    558  2.8
 11500  -10.5  13.1   325   15    8   6.5   3.6    9.9  49.8    -0.5    506  2.6
 11000   -9.6  14.7   325   15    8   6.0   3.3    9.3  48.7    -1.0    464  2.4
 10500   -8.6  16.5   330   15    8   7.7   4.2    8.8  47.8    -1.5    421  2.1
 10250   -8.0  17.6   330   15    8   8.0   4.4    8.6  47.5    -1.7    396  2.0
 10000   -7.4  18.7   335   15    8   8.1   4.5    8.5  47.3    -1.9    371  1.9
  9750   -6.9  19.6   335   15    8   7.2   4.0    8.4  47.0    -2.0    347  1.8
  9500   -6.4  20.5   335   14    7   6.3   3.5    8.1  46.6    -2.3    325  1.7
  9250   -5.9  21.4   330   14    7   6.5   3.6    7.9  46.1    -2.5    304  1.5
  9000   -5.5  22.1   330   13    7   6.5   3.6    7.6  45.7    -2.8    282  1.4
  8750   -5.0  23.0   330   12    6   6.5   3.6    7.3  45.2    -3.1    260  1.3
  8500   -4.5  23.9   330   12    6   6.5   3.6    7.1  44.8    -3.3    239  1.2
  8250   -4.0  24.8   335   11    6   6.5   3.6    6.8  44.3    -3.6    217  1.1
  8000   -3.6  25.5   335   10    5   6.5   3.6    6.6  43.9    -3.9    196  1.0
  7750   -3.1  26.4   330   10    5   6.5   3.6    6.3  43.4    -4.1    174  0.9
  7500   -2.6  27.3   320   11    6   6.5   3.6    6.1  43.0    -4.4    153  0.8
  7250   -2.2  28.0   315   12    6   6.6   3.6    5.8  42.5    -4.7    131  0.7
  7000   -1.7  28.9   310   13    7   6.5   3.6    5.6  42.1    -5.0    109  0.6
  6750   -1.2  29.8   305   13    7   6.8   3.7    5.4  41.6    -5.2     88  0.4
  6500   -0.7  30.7   300   12    6   5.6   3.1    5.1  41.2    -5.5     66  0.3
  6250   -0.4  31.3   295   12    6   4.5   2.5    4.7  40.5    -5.9     49  0.2
  6000   -0.1  31.8   290   12    6   4.3   2.4    4.3  39.8    -6.3     31  0.2
  5750    0.3  32.5   295   10    5   5.6   3.1    3.9  39.1    -6.7     14  0.1
  5500    0.8  33.4   300    8    4   8.4   4.6    3.7  38.7    -7.0      M    M
  5250    1.4  34.5   315    6    3   8.7   4.8    3.7  38.6    -7.1      M    M
  5000    2.1  35.8   335    5    3   9.4   5.1    3.6  38.5    -7.2      M    M

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

           05/18/2017 at 0900 MDT          |       05/18/2017 at 1200 MDT
                                           |
K index... +18.6  LI... +2.0               | K index... +13.4  LI... +1.1
CAPE... +3.8  CIN... -0.6                  | CAPE... +26.9  CIN... -2.6
                                           |
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 -53.6 -64.5  280  11  6   2.9   1.6 | -53.5 -64.3  280  11  5   2.6   1.5
 45000 -49.3 -56.7  270  12  6   2.9   1.6 | -49.5 -57.1  280  13  7   2.7   1.5
 40000 -46.9 -52.4  240  16  8   1.5   0.8 | -47.0 -52.6  260  14  7   1.5   0.8
 38000 -46.1 -51.0  230  16  8   1.1   0.6 | -46.2 -51.2  250  13  6   1.2   0.7
 36000 -45.4 -49.7  210  15  8   1.1   0.6 | -45.5 -49.9  225  10  5   1.2   0.7
 34000 -44.7 -48.5  190  15  8   1.3   0.7 | -44.7 -48.5  195   9  4   1.4   0.8
 32000 -44.9 -48.8  135  23 12  -0.5  -0.3 | -44.5 -48.1  140  14  7   0.2   0.1
 30000 -45.2 -49.4  115  39 20  -1.0  -0.6 | -44.4 -47.9  125  24 12  -0.1  -0.0
 29000 -44.3 -47.7  115  43 22   5.0   2.7 | -43.5 -46.3  115  30 15   3.1   1.7
 28000 -42.4 -44.3  110  45 23   5.0   2.7 | -42.6 -44.7  110  35 18   3.1   1.7
 27000 -41.0 -41.8  105  46 24   5.0   2.8 | -41.6 -42.9  105  40 21   3.2   1.8
 26000 -39.3 -38.7  105  44 23   6.2   3.4 | -40.3 -40.5  100  41 21   6.2   3.4
 25000 -37.4 -35.3  110  39 20   6.3   3.4 | -38.4 -37.1  105  35 18   6.2   3.4
 24000 -35.6 -32.1  120  33 17   6.3   3.4 | -36.5 -33.7  105  30 16   6.3   3.4
 23000 -33.7 -28.7  125  27 14   5.8   3.2 | -34.6 -30.3  105  24 12   7.1   3.9
 22000 -32.0 -25.6  120  18  9   5.8   3.2 | -32.5 -26.5  105  16  8   7.1   3.9
 21000 -30.3 -22.5  110   9  4   5.7   3.1 | -30.4 -22.7  105   8  4   7.0   3.9
 20000 -28.1 -18.6  095   4  2   8.3   4.5 | -28.1 -18.6  105   4  2   7.7   4.3
 19500 -26.9 -16.4  095   3  2   8.3   4.6 | -27.0 -16.6  110   3  1   7.8   4.3
 19000 -25.6 -14.1  085   2  1   8.3   4.6 | -25.8 -14.4  125   2  1   7.8   4.3
 18500 -24.4 -11.9  065   1  1   8.3   4.6 | -24.7 -12.5  150   1  1   7.8   4.3
 18000 -23.2  -9.8  005   1  1   7.7   4.2 | -23.5 -10.3  215   1  0   8.2   4.5
 17500 -22.1  -7.8  360   3  2   7.5   4.1 | -22.3  -8.1  295   2  1   8.3   4.5
 17000 -21.0  -5.8  360   5  3   7.4   4.1 | -21.0  -5.8  310   3  2   7.5   4.1
 16500 -19.9  -3.8  350   7  3   7.1   3.9 | -20.1  -4.2  295   5  3   5.7   3.1
 16000 -18.9  -2.0  345   8  4   7.3   4.0 | -19.3  -2.7  285   7  4   5.8   3.2
 15500 -17.9  -0.2  335   9  5   5.9   3.3 | -18.4  -1.1  280  10  5   5.6   3.1
 15000 -17.0   1.4  330  11  6   6.1   3.3 | -17.6   0.3  280  13  6   5.5   3.0
 14500 -16.1   3.0  325  13  7   5.4   3.0 | -16.7   1.9  280  15  8   6.8   3.7
 14000 -15.4   4.3  320  15  8   5.3   2.9 | -15.1   4.8  280  17  9   6.9   3.8
 13500 -14.1   6.6  315  18  9   7.0   3.8 | -14.1   6.6  285  18  9   7.1   3.9
 13000 -13.0   8.6  315  19 10   6.8   3.7 | -13.0   8.6  290  18  9   7.1   3.9
 12500 -12.0  10.4  315  19 10   7.9   4.3 | -11.9  10.6  290  17  9   7.8   4.3
 12000 -10.8  12.6  315  19 10   7.8   4.3 | -10.7  12.7  295  17  9   7.8   4.3
 11500  -9.7  14.5  320  18  9   7.7   4.2 |  -9.6  14.7  295  17  9   7.3   4.0
 11000  -8.6  16.5  320  17  9   7.8   4.3 |  -8.6  16.5  295  16  8   7.3   4.0
 10500  -7.7  18.1  330  16  8   5.1   2.8 |  -7.5  18.5  295  16  8   6.8   3.7
 10250  -7.3  18.9  335  16  8   5.3   2.9 |  -7.0  19.4  295  16  8   7.2   3.9
 10000  -6.9  19.6  340  16  8   6.6   3.6 |  -6.5  20.3  290  15  8   8.5   4.7
  9750  -6.4  20.5  345  17  8   6.5   3.6 |  -5.9  21.4  290  15  8   8.1   4.4
  9500  -6.0  21.2  345  18  9   5.1   2.8 |  -5.3  22.5  295  15  8   7.1   3.9
  9250  -5.6  21.9  350  19 10   5.8   3.2 |  -4.8  23.4  295  14  7   7.3   4.0
  9000  -5.2  22.6  355  20 10   4.5   2.4 |  -4.3  24.3  295  14  7   7.5   4.1
  8750  -4.9  23.2  355  20 10   4.2   2.3 |  -3.7  25.3  295  14  7   7.2   4.0
  8500  -4.5  23.9  350  19 10   5.4   2.9 |  -3.2  26.2  295  13  7   6.8   3.7
  8250  -4.2  24.4  350  18  9   5.1   2.8 |  -2.7  27.1  295  12  6   7.0   3.9
  8000  -3.8  25.2  345  18  9   6.0   3.3 |  -2.2  28.0  290  11  6   7.0   3.8
  7750  -3.3  26.1  340  17  9   5.5   3.0 |  -1.8  28.8  285  10  5   6.8   3.7
  7500  -3.0  26.6  330  17  9   4.9   2.7 |  -1.3  29.7  280   8  4   6.0   3.3
  7250  -2.6  27.3  320  17  9   4.1   2.2 |  -0.9  30.4  270   7  4   8.6   4.7
  7000  -2.4  27.7  310  17  8   2.4   1.3 |  -0.1  31.8  270   7  4  11.3   6.2
  6750  -2.2  28.0  300  16  8   2.5   1.4 |   0.7  33.3  270   7  4   9.6   5.3
  6500  -2.0  28.4  290  16  8   3.2   1.8 |   1.4  34.5  270   7  4   9.5   5.2
  6250  -1.7  28.9  285  15  8   5.5   3.0 |   2.1  35.8  270   7  3  11.5   6.3
  6000  -1.2  29.8  280  14  7   7.1   3.9 |   3.0  37.4  265   7  3  12.0   6.6
  5750  -0.7  30.7  275  12  6   8.1   4.4 |   3.9  39.0  265   6  3  10.3   5.6
  5500  -0.1  31.8  275  10  5   8.0   4.4 |   4.7  40.5  265   6  3  12.6   6.9
  5250   0.4  32.7  275  10  5   4.8   2.6 |   5.8  42.4  265   6  3  18.8  10.3
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/18/2017 at 1500 MDT          |       05/18/2017 at 1800 MDT
                                           |
K index... +8.3  LI... +0.3                | K index... +12.1  LI... +0.6
CAPE... +18.5  CIN... -4.9                 | CAPE... +0.6  CIN... -4.8
                                           |
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 -53.8 -64.8  280  12  6   2.7   1.5 | -53.7 -64.7  285  13  7   2.6   1.4
 45000 -49.6 -57.3  285  15  8   2.3   1.3 | -49.7 -57.5  275  18  9   1.9   1.1
 40000 -46.5 -51.7  265  12  6   2.1   1.1 | -47.2 -53.0  270  12  6   1.6   0.9
 38000 -45.5 -49.9  260  10  5   0.7   0.4 | -46.3 -51.3  265   8  4   1.2   0.7
 36000 -45.1 -49.2  235   6  3   0.7   0.4 | -45.6 -50.1  225   3  2   1.2   0.7
 34000 -44.6 -48.3  180   4  2   0.9   0.5 | -44.9 -48.8  135   5  3   1.2   0.7
 32000 -44.9 -48.8  120  10  5  -0.6  -0.3 | -45.0 -49.0  090  15  8  -0.4  -0.2
 30000 -45.2 -49.4  110  20 10   1.0   0.6 | -45.3 -49.5  080  29 15   1.7   1.0
 29000 -44.2 -47.6  105  29 15   3.8   2.1 | -44.1 -47.4  085  34 18   4.0   2.2
 28000 -43.0 -45.4  105  39 20   3.8   2.1 | -42.9 -45.2  090  40 20   4.0   2.2
 27000 -41.9 -43.4  105  49 25   3.9   2.1 | -41.7 -43.1  095  45 23   4.1   2.2
 26000 -40.4 -40.7  105  49 25   6.3   3.4 | -40.2 -40.4  095  43 22   5.5   3.0
 25000 -38.5 -37.3  110  41 21   6.3   3.5 | -38.6 -37.5  100  34 18   5.5   3.0
 24000 -36.6 -33.9  115  33 17   6.4   3.5 | -36.9 -34.4  105  25 13   5.6   3.1
 23000 -34.6 -30.3  120  26 13   7.3   4.0 | -34.9 -30.8  110  19 10   7.8   4.3
 22000 -32.4 -26.3  125  18  9   7.3   4.0 | -32.5 -26.5  110  15  8   7.9   4.3
 21000 -30.2 -22.4  140  11  6   7.2   4.0 | -30.2 -22.4  110  11  6   7.9   4.3
 20000 -27.9 -18.2  160   9  4   8.0   4.4 | -27.7 -17.9  115   7  4   8.3   4.5
 19500 -26.7 -16.1  165   8  4   8.0   4.4 | -26.5 -15.7  120   5  3   8.3   4.5
 19000 -25.5 -13.9  175   8  4   8.0   4.4 | -25.3 -13.5  135   4  2   8.3   4.5
 18500 -24.3 -11.7  180   9  4   8.1   4.4 | -24.0 -11.2  165   2  1   8.3   4.6
 18000 -23.1  -9.6  185   8  4   7.6   4.2 | -22.8  -9.0  210   2  1   7.6   4.2
 17500 -22.0  -7.6  195   7  4   7.5   4.1 | -21.7  -7.1  240   2  1   7.6   4.2
 17000 -20.8  -5.4  200   6  3   7.3   4.0 | -20.6  -5.1  260   3  2   7.5   4.1
 16500 -19.8  -3.6  220   6  3   7.0   3.8 | -19.5  -3.1  270   5  2   7.3   4.0
 16000 -18.7  -1.7  235   6  3   7.0   3.8 | -18.4  -1.1  275   6  3   7.3   4.0
 15500 -17.7   0.1  245   7  4   7.0   3.9 | -17.3   0.9  275   7  4   7.3   4.0
 15000 -16.6   2.1  260   9  5   7.0   3.9 | -16.2   2.8  275   9  4   7.3   4.0
 14500 -15.0   5.0  270  11  5   7.1   3.9 | -14.5   5.9  280  10  5   7.6   4.2
 14000 -13.9   7.0  275  12  6   7.2   3.9 | -13.4   7.9  280  11  6   7.7   4.2
 13500 -12.8   9.0  285  12  6   7.6   4.1 | -12.3   9.9  285  11  6   7.9   4.3
 13000 -11.7  10.9  295  13  7   7.5   4.1 | -11.1  12.0  290  11  5   7.8   4.3
 12500 -10.6  12.9  300  13  7   7.5   4.1 | -10.0  14.0  290  10  5   7.4   4.1
 12000  -9.5  14.9  300  13  7   7.6   4.2 |  -8.9  16.0  290  10  5   7.5   4.1
 11500  -8.3  17.1  300  13  7   7.9   4.4 |  -7.8  18.0  290   9  5   7.8   4.3
 11000  -7.2  19.0  300  13  7   7.8   4.3 |  -6.6  20.1  285   9  5   7.7   4.2
 10500  -6.1  21.0  300  13  6   6.8   3.7 |  -5.6  21.9  285   9  5   7.2   3.9
 10250  -5.6  21.9  295  12  6   8.1   4.4 |  -5.0  23.0  280   9  5   8.1   4.4
 10000  -4.9  23.2  295  12  6   9.9   5.4 |  -4.4  24.1  280   9  5   8.8   4.8
  9750  -4.2  24.4  290  11  6   8.6   4.7 |  -3.8  25.2  275   9  5   7.8   4.3
  9500  -3.7  25.3  290  11  6   7.4   4.1 |  -3.2  26.2  270   9  5   7.5   4.1
  9250  -3.1  26.4  285  10  5   7.8   4.3 |  -2.6  27.3  270   9  5   7.6   4.2
  9000  -2.6  27.3  280   9  5   7.5   4.1 |  -2.1  28.2  265   9  5   8.2   4.5
  8750  -2.0  28.4  280   9  5   8.1   4.4 |  -1.5  29.3  260   9  4   8.5   4.6
  8500  -1.4  29.5  275   9  4   8.7   4.8 |  -0.9  30.4  260   8  4   8.1   4.4
  8250  -0.8  30.6  275   8  4   9.1   5.0 |  -0.3  31.5  255   8  4   8.9   4.9
  8000  -0.2  31.6  275   8  4  10.3   5.6 |   0.5  32.9  250   8  4  10.2   5.6
  7750   0.6  33.1  270   8  4  10.0   5.5 |   1.2  34.2  250   8  4   9.9   5.4
  7500   1.3  34.3  270   7  4   9.5   5.2 |   1.9  35.4  250   8  4   9.1   5.0
  7250   2.0  35.6  270   7  4   9.7   5.3 |   2.6  36.7  250   8  4  10.4   5.7
  7000   2.8  37.0  270   7  4   9.9   5.4 |   3.4  38.1  245   8  4  11.1   6.1
  6750   3.5  38.3  270   7  4   9.8   5.4 |   4.2  39.6  245   8  4   9.6   5.3
  6500   4.2  39.6  270   7  4  10.1   5.6 |   4.9  40.8  245   8  4   9.5   5.2
  6250   5.0  41.0  265   7  4  11.4   6.2 |   5.7  42.3  245   7  4  10.8   5.9
  6000   5.9  42.6  265   7  3  12.0   6.6 |   6.5  43.7  245   7  4  10.8   5.9
  5750   6.8  44.2  265   7  3  10.8   5.9 |   7.3  45.1  245   7  4   9.3   5.1
  5500   7.6  45.7  265   6  3  12.8   7.0 |   7.9  46.2  245   7  3   9.4   5.1
  5250   8.7  47.7  270   6  3  18.3  10.0 |   8.7  47.7  245   7  3  11.4   6.3
  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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