Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 301243
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0643 MDT Tuesday, May 30, 2017

This forecast is for Tuesday, May 30, 2017:

If the trigger temperature of 66.4 F/19.1 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1067 ft/min (5.4 m/s)
   Maximum height of thermals.................. 17136 ft MSL (11851 ft AGL)

Forecast maximum temperature................... 76.0 F/24.9 C
Time of trigger temperature.................... 1015 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 12834 ft MSL (7548 ft AGL)
Thermal soaring outlook for Wednesday 05/31.... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 17830 ft MSL (12545 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Weak PVA
Potential height of wave....................... 31603 ft MSL (26318 ft AGL)
Wave soaring outlook for Wednesday 05/31....... Poor

Remarks...

Sunrise/Sunset.................... 05:34:23 / 20:19:38 MDT
Total possible sunshine........... 14 hr 45 min 16 sec (885 min 16 sec)
Altitude of sun at 12:57:12 MDT... 72.09 degrees

Upper air data from rawinsonde observation taken on 05/30/2017 at 0600 MDT

Freezing level.................. 12209 ft MSL (6924 ft AGL)
Convective condensation level... 13436 ft MSL (8151 ft AGL)
Lifted condensation level....... 14425 ft MSL (9140 ft AGL)
Lifted index.................... -3.7
K index......................... +15.2

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  -59.4 -74.9   300   22   11  -3.1  -1.7  100.0 212.0    43.3      M    M
 45000  -59.9 -75.8   300   29   15   3.4   1.9   73.2 163.8    30.0      M    M
 40000  -63.3 -81.9   335   32   16   1.9   1.1   45.1 113.1    13.6      M    M
 38000  -59.1 -74.4   340   31   16   7.1   3.9   42.3 108.2    12.2      M    M
 36000  -54.9 -66.8   335   28   15   7.1   3.9   40.0 104.1    10.9      M    M
 34000  -50.4 -58.7   330   28   14   8.0   4.4   38.3 100.9     9.9      M    M
 32000  -45.6 -50.1   320   30   15   8.0   4.4   36.7  98.1     9.0      M    M
 30000  -39.9 -39.8   310   31   16   8.9   4.9   35.7  96.3     8.5      M    M
 29000  -37.2 -35.0   315   31   16   8.9   4.9   35.2  95.4     8.3      M    M
 28000  -34.5 -30.1   315   32   16   8.9   4.9   34.9  94.8     8.1      M    M
 27000  -31.9 -25.4   320   32   16   6.9   3.8   34.7  94.4     8.0      M    M
 26000  -30.3 -22.5   320   32   17   5.2   2.8   32.8  91.1     6.7      M    M
 25000  -28.8 -19.8   325   33   17   5.2   2.9   31.2  88.2     5.4      M    M
 24000  -26.5 -15.7   325   31   16   9.1   5.0   30.4  86.7     4.8      M    M
 23000  -23.8 -10.8   315   30   16   9.1   5.0   30.1  86.1     4.6      M    M
 22000  -21.1  -6.0   310   29   15   9.1   5.0   29.9  85.8     4.5      M    M
 21000  -18.7  -1.7   305   29   15   7.2   3.9   29.3  84.7     4.0      M    M
 20000  -16.6   2.1   305   29   15   7.0   3.8   28.4  83.1     3.3      M    M
 19500  -15.7   3.7   305   28   14   5.8   3.2   27.7  81.9     2.7      M    M
 19000  -14.8   5.4   305   27   14   6.8   3.8   27.1  80.7     2.2      M    M
 18500  -13.5   7.7   305   26   13   8.8   4.8   26.8  80.3     2.0      M    M
 18000  -12.3   9.9   305   25   13   5.4   3.0   26.6  79.9     1.8      M    M
 17500  -11.8  10.8   305   23   12   3.2   1.7   25.5  77.9     0.8      M    M
 17000  -11.2  11.8   310   22   11   7.3   4.0   24.6  76.2    -0.1   1063  5.4
 16500  -10.0  14.0   310   20   10   8.2   4.5   24.3  75.8    -0.3   1011  5.1
 16000   -8.7  16.3   315   18    9   8.3   4.5   24.1  75.4    -0.5    960  4.9
 15500   -7.5  18.5   315   18    9   8.3   4.6   23.8  74.9    -0.7    908  4.6
 15000   -5.7  21.7   320   17    9   8.1   4.4   23.5  74.3    -1.1    830  4.2
 14500   -4.5  23.9   325   16    8   6.8   3.7   23.1  73.5    -1.4    781  4.0
 14000   -3.5  25.7   325   16    8   8.6   4.7   22.7  72.9    -1.9    736  3.7
 13500   -2.2  28.0   320   13    7   6.1   3.3   22.4  72.4    -2.0    682  3.5
 13000   -1.6  29.1   320   11    6   6.4   3.5   21.7  71.1    -2.9    650  3.3
 12500   -0.5  31.1   310   10    5   8.4   4.6   21.4  70.5    -3.3    602  3.1
 12000    0.7  33.3   305    8    4   8.4   4.6   21.2  70.1    -3.6    551  2.8
 11500    1.9  35.4   295    7    4   8.4   4.6   20.9  69.7    -3.9    500  2.5
 11000    3.1  37.6   285    7    4   8.4   4.6   20.7  69.3    -4.2    449  2.3
 10500    4.3  39.7   275    7    4   8.4   4.6   20.5  68.9    -4.4    399  2.0
 10250    4.9  40.8   270    7    4   8.3   4.6   20.4  68.7    -4.6    373  1.9
 10000    5.5  41.9   265    7    4   8.3   4.5   20.3  68.5    -4.7    348  1.8
  9750    6.1  43.0   250    7    4   8.3   4.5   20.2  68.3    -4.8    323  1.6
  9500    6.7  44.1   235    7    4   8.3   4.5   20.1  68.1    -5.0    297  1.5
  9250    7.3  45.1   225    8    4   8.3   4.6   19.9  67.9    -5.1    272  1.4
  9000    7.9  46.2   215    9    5   8.2   4.5   19.8  67.7    -5.3    247  1.3
  8750    8.5  47.3   210   10    5   8.7   4.8   19.7  67.5    -5.4    221  1.1
  8500    9.1  48.4   210   11    5   6.9   3.8   19.6  67.3    -5.6    196  1.0
  8250    9.5  49.1   205   11    6   4.5   2.5   19.2  66.6    -5.9    177  0.9
  8000    9.8  49.6   205   12    6   4.6   2.5   18.9  65.9    -6.4    160  0.8
  7750   10.1  50.2   205   13    7   4.6   2.5   18.4  65.2    -6.8    143  0.7
  7500   10.5  50.9   205   14    7   4.6   2.5   18.0  64.5    -7.2    125  0.6
  7250   10.8  51.4   205   15    8   4.6   2.5   17.7  63.8    -7.6    108  0.5
  7000   11.1  52.0   205   16    8   4.7   2.6   17.3  63.1    -8.0     91  0.5
  6750   11.5  52.7   205   16    8   4.4   2.4   16.9  62.4    -8.4     73  0.4
  6500   11.8  53.2   205   17    9   5.3   2.9   16.5  61.7    -8.9     56  0.3
  6250   12.1  53.8   205   17    9   2.0   1.1   16.1  61.0    -9.3     39  0.2
  6000   12.0  53.6   205   18    9  -3.8  -2.1   15.2  59.4   -10.2     35  0.2
  5750   11.7  53.1   205   12    6  -1.8  -1.0   14.2  57.6   -11.2     36  0.2
  5500   11.4  52.5   205    6    3  -9.9  -5.4   13.2  55.8   -12.3     37  0.2

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

           05/30/2017 at 0900 MDT          |       05/30/2017 at 1200 MDT
                                           |
K index... +11.8  LI... -0.1               | K index... +6.3  LI... -0.7
CAPE... +23.1  CIN... -52.8                | CAPE... +97.3  CIN... -20.1
                                           |
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 -60.6 -77.1  305  21 11  -0.5  -0.3 | -61.6 -78.9  310  20 10  -0.7  -0.4
 45000 -61.3 -78.3  315  25 13  -0.0  -0.0 | -62.4 -80.3  310  22 12   0.9   0.5
 40000 -61.4 -78.5  330  28 14  -0.5  -0.3 | -61.0 -77.8  320  25 13   0.2   0.1
 38000 -57.9 -72.2  325  27 14   7.0   3.8 | -57.3 -71.1  315  26 13   7.1   3.9
 36000 -53.7 -64.7  315  26 14   7.0   3.8 | -53.1 -63.6  310  26 14   7.1   3.9
 34000 -49.1 -56.4  315  26 13   8.3   4.5 | -48.5 -55.3  305  27 14   8.3   4.5
 32000 -44.2 -47.6  315  27 14   8.3   4.5 | -43.5 -46.3  305  27 14   8.3   4.5
 30000 -39.0 -38.2  315  26 14   7.1   3.9 | -38.3 -36.9  305  26 13   7.2   3.9
 29000 -36.9 -34.4  315  26 13   7.1   3.9 | -36.2 -33.2  300  26 13   7.2   3.9
 28000 -34.8 -30.6  315  25 13   7.0   3.9 | -34.0 -29.2  300  25 13   7.2   3.9
 27000 -32.6 -26.7  315  25 13   7.3   4.0 | -31.9 -25.4  300  25 13   7.1   3.9
 26000 -30.5 -22.9  315  26 13   7.3   4.0 | -29.8 -21.6  305  25 13   7.1   3.9
 25000 -28.3 -18.9  315  26 13   7.3   4.0 | -27.7 -17.9  305  25 13   7.1   3.9
 24000 -26.0 -14.8  315  26 14   8.0   4.4 | -25.4 -13.7  305  25 13   8.1   4.4
 23000 -23.6 -10.5  315  26 13   8.0   4.4 | -23.0  -9.4  305  24 13   8.1   4.4
 22000 -21.3  -6.3  315  26 13   8.0   4.4 | -20.6  -5.1  310  24 12   8.2   4.5
 21000 -18.9  -2.0  315  25 13   7.7   4.2 | -18.3  -0.9  310  23 12   7.5   4.1
 20000 -16.6   2.1  315  25 13   7.7   4.2 | -16.1   3.0  315  23 12   7.5   4.1
 19500 -15.5   4.1  315  24 12   7.7   4.2 | -15.0   5.0  315  23 12   7.5   4.1
 19000 -14.3   6.3  315  24 12   7.6   4.2 | -13.8   7.2  315  23 12   7.3   4.0
 18500 -13.2   8.2  320  23 12   7.3   4.0 | -12.8   9.0  315  23 12   7.0   3.9
 18000 -12.1  10.2  320  23 12   7.3   4.0 | -11.7  10.9  315  23 12   7.0   3.9
 17500 -11.0  12.2  320  22 11   7.0   3.8 | -10.7  12.7  315  22 11   7.0   3.8
 17000 -10.0  14.0  320  22 11   7.0   3.9 |  -9.7  14.5  315  21 11   7.0   3.8
 16500  -8.9  16.0  325  21 11   7.0   3.9 |  -8.6  16.5  315  20 10   7.2   3.9
 16000  -7.4  18.7  325  20 10   7.0   3.9 |  -7.5  18.5  315  19 10   7.3   4.0
 15500  -6.4  20.5  325  19 10   7.1   3.9 |  -5.9  21.4  315  17  9   7.3   4.0
 15000  -5.3  22.5  330  18  9   7.1   3.9 |  -4.8  23.4  315  16  8   7.2   4.0
 14500  -4.3  24.3  330  17  9   6.9   3.8 |  -3.7  25.3  315  15  8   7.2   4.0
 14000  -3.3  26.1  335  16  8   6.7   3.7 |  -2.7  27.1  320  14  7   7.3   4.0
 13500  -2.3  27.9  335  14  7   7.0   3.8 |  -1.6  29.1  320  13  7   7.4   4.1
 13000  -1.3  29.7  335  13  6   7.8   4.3 |  -0.5  31.1  320  12  6   7.8   4.3
 12500  -0.1  31.8  340  11  6   7.8   4.3 |   0.6  33.1  325  10  5   7.8   4.3
 12000   1.0  33.8  340   9  5   8.0   4.4 |   1.8  35.2  325   9  4   7.7   4.2
 11500   2.1  35.8  345   8  4   8.2   4.5 |   2.9  37.2  335   7  4   7.8   4.3
 11000   3.4  38.1  345   6  3   9.1   5.0 |   4.1  39.4  340   5  3   7.9   4.3
 10500   4.7  40.5  345   5  2   7.2   4.0 |   5.2  41.4  360   4  2   5.9   3.2
 10250   5.0  41.0  340   4  2   4.5   2.5 |   5.5  41.9  005   3  2   4.9   2.7
 10000   5.5  41.9  335   4  2   9.6   5.2 |   6.1  43.0  010   3  2   9.9   5.4
  9750   6.4  43.5  320   3  2  13.5   7.4 |   6.9  44.4  020   3  1  12.2   6.7
  9500   7.3  45.1  305   3  1  10.4   5.7 |   7.6  45.7  030   2  1  10.2   5.6
  9250   7.9  46.2  285   3  2   6.2   3.4 |   8.2  46.8  030   2  1   7.0   3.8
  9000   8.3  46.9  265   3  2   6.8   3.7 |   8.7  47.7  035   2  1   8.8   4.8
  8750   8.9  48.0  250   4  2   8.9   4.9 |   9.5  49.1  035   2  1  11.3   6.2
  8500   9.5  49.1  240   5  3   7.6   4.2 |  10.2  50.4  035   2  1  10.0   5.5
  8250  10.0  50.0  230   5  3   6.4   3.5 |  10.9  51.6  035   2  1   9.3   5.1
  8000  10.4  50.7  220   6  3   6.8   3.8 |  11.5  52.7  035   2  1   9.7   5.3
  7750  10.9  51.6  215   6  3   7.3   4.0 |  12.3  54.1  030   2  1  10.2   5.6
  7500  11.4  52.5  210   6  3   6.3   3.5 |  13.0  55.4  030   2  1  10.4   5.7
  7250  11.8  53.2  205   5  3   5.3   2.9 |  13.8  56.8  030   2  1  10.4   5.7
  7000  12.2  54.0  205   4  2   6.0   3.3 |  14.6  58.3  030   2  1  10.2   5.6
  6750  12.6  54.7  200   4  2   4.4   2.4 |  15.3  59.5  030   2  1  10.0   5.5
  6500  12.8  55.0  195   3  2   2.2   1.2 |  16.1  61.0  025   2  1  10.3   5.7
  6250  13.0  55.4  200   3  1   1.9   1.1 |  16.8  62.2  025   2  1  10.5   5.7
  6000  13.1  55.6  200   2  1   2.2   1.2 |  17.6  63.7  020   2  1  10.5   5.8
  5750  13.4  56.1  205   2  1   8.7   4.8 |  18.6  65.5  020   2  1  16.7   9.2
  5500  14.4  57.9  215   2  1  18.6  10.2 |  20.2  68.4  020   2  1  26.6  14.6

           05/30/2017 at 1500 MDT          |       05/30/2017 at 1800 MDT
                                           |
K index... +17.3  LI... -0.2               | K index... +24.4  LI... -0.7
CAPE... +34.5  CIN... -65.1                | CAPE... +76.4  CIN... -58.8
                                           |
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 -61.5 -78.7  300  17  9  -1.0  -0.6 | -61.9 -79.4  305  17  9  -1.0  -0.6
 45000 -62.6 -80.7  305  21 11   1.4   0.8 | -63.1 -81.6  305  19 10   1.6   0.9
 40000 -60.4 -76.7  305  20 11   0.9   0.5 | -60.7 -77.3  280  20 10   0.9   0.5
 38000 -56.8 -70.2  305  22 11   6.7   3.7 | -56.8 -70.2  285  20 10   7.0   3.9
 36000 -52.8 -63.0  305  24 12   6.7   3.7 | -52.6 -62.7  285  21 11   7.0   3.9
 34000 -48.3 -54.9  305  25 13   8.2   4.5 | -48.1 -54.6  290  23 12   8.1   4.4
 32000 -42.8 -45.0  300  27 14   8.2   4.5 | -42.6 -44.7  290  26 13   8.1   4.4
 30000 -38.3 -36.9  300  28 15   7.0   3.9 | -38.1 -36.6  290  29 15   7.3   4.0
 29000 -36.2 -33.2  300  29 15   7.0   3.9 | -35.9 -32.6  295  31 16   7.3   4.0
 28000 -34.1 -29.4  300  30 15   7.0   3.9 | -33.7 -28.7  295  32 17   7.3   4.0
 27000 -32.0 -25.6  300  30 15   7.1   3.9 | -31.5 -24.7  295  33 17   7.5   4.1
 26000 -29.9 -21.8  300  29 15   7.1   3.9 | -29.2 -20.6  295  32 17   7.5   4.1
 25000 -27.7 -17.9  300  29 15   7.1   3.9 | -27.0 -16.6  295  32 16   7.5   4.1
 24000 -25.5 -13.9  300  28 15   8.2   4.5 | -24.7 -12.5  295  31 16   8.1   4.5
 23000 -23.0  -9.4  300  27 14   8.3   4.5 | -22.2  -8.0  295  29 15   8.1   4.5
 22000 -20.5  -4.9  300  27 14   8.3   4.6 | -19.8  -3.6  290  28 14   8.2   4.5
 21000 -18.2  -0.8  300  26 13   7.4   4.1 | -17.5   0.5  290  27 14   7.3   4.0
 20000 -16.0   3.2  300  25 13   7.4   4.1 | -15.4   4.3  290  27 14   7.4   4.1
 19500 -14.9   5.2  300  25 13   7.4   4.1 | -14.3   6.3  290  27 14   7.5   4.1
 19000 -13.8   7.2  300  24 13   7.4   4.1 | -13.2   8.2  290  27 14   7.6   4.2
 18500 -12.7   9.1  300  24 12   7.3   4.0 | -12.1  10.2  290  27 14   7.7   4.2
 18000 -11.6  11.1  300  24 12   7.2   3.9 | -11.0  12.2  290  27 14   7.6   4.2
 17500 -10.5  13.1  300  23 12   8.6   4.7 |  -9.8  14.4  290  26 13   8.3   4.5
 17000  -9.2  15.4  300  23 12   8.5   4.7 |  -8.6  16.5  290  25 13   8.3   4.5
 16500  -7.4  18.7  300  23 12   8.6   4.7 |  -6.8  19.8  290  22 11   8.1   4.5
 16000  -6.1  21.0  300  21 11   8.6   4.7 |  -5.7  21.7  290  19 10   8.2   4.5
 15500  -4.9  23.2  295  20 10   8.8   4.8 |  -4.5  23.9  285  17  9   7.9   4.3
 15000  -3.6  25.5  295  18  9   8.8   4.8 |  -3.4  25.9  280  13  7   7.8   4.3
 14500  -2.4  27.7  295  16  8   8.4   4.6 |  -2.2  28.0  270  11  5   7.7   4.2
 14000  -1.2  29.8  295  14  7   7.9   4.4 |  -1.1  30.0  250   8  4   7.6   4.2
 13500  -0.1  31.8  295  11  6   7.6   4.2 |  -0.0  32.0  225   7  4   7.6   4.2
 13000   1.0  33.8  295   8  4   7.0   3.9 |   1.1  34.0  205   6  3   7.4   4.1
 12500   2.1  35.8  295   5  3   7.1   3.9 |   2.2  36.0  180   6  3   7.5   4.1
 12000   3.2  37.8  305   2  1   7.1   3.9 |   3.4  38.1  165   5  3   8.2   4.5
 11500   4.2  39.6  065   1  1   7.2   3.9 |   4.6  40.3  150   5  3   8.2   4.5
 11000   5.3  41.5  090   2  1   7.9   4.3 |   5.9  42.6  140   4  2   8.9   4.9
 10500   6.5  43.7  090   3  1   5.5   3.0 |   7.2  45.0  125   4  2   6.6   3.6
 10250   6.8  44.2  090   3  2   5.0   2.7 |   7.6  45.7  125   4  2   6.3   3.4
 10000   7.4  45.3  090   3  2  10.5   5.8 |   8.3  46.9  120   4  2  10.7   5.9
  9750   8.2  46.8  090   3  2  12.0   6.6 |   9.1  48.4  120   4  2  11.5   6.3
  9500   9.0  48.2  085   3  2  10.7   5.8 |   9.9  49.8  115   3  2  10.4   5.7
  9250   9.7  49.5  085   3  2   8.3   4.6 |  10.6  51.1  115   3  2   7.6   4.2
  9000  10.3  50.5  085   3  2   9.7   5.3 |  11.2  52.2  115   3  2   9.3   5.1
  8750  11.1  52.0  085   3  2  11.7   6.4 |  12.0  53.6  110   3  2  11.8   6.5
  8500  12.0  53.6  080   3  2  10.5   5.8 |  12.8  55.0  110   3  1  10.6   5.8
  8250  12.7  54.9  080   3  1   9.8   5.4 |  13.6  56.5  105   3  1   9.9   5.4
  8000  13.5  56.3  080   3  1   9.7   5.3 |  14.3  57.7  105   2  1   9.8   5.4
  7750  14.2  57.6  075   3  1   9.4   5.1 |  15.0  59.0  100   2  1   9.8   5.4
  7500  14.9  58.8  075   3  1   9.8   5.4 |  15.8  60.4  100   2  1   9.8   5.4
  7250  15.6  60.1  070   3  1  10.2   5.6 |  16.5  61.7  095   2  1   9.9   5.4
  7000  16.4  61.5  070   3  1  10.2   5.6 |  17.2  63.0  090   2  1   9.7   5.3
  6750  17.2  63.0  070   3  1  10.8   5.9 |  17.9  64.2  085   2  1   9.4   5.2
  6500  18.0  64.4  065   3  1  10.7   5.9 |  18.7  65.7  085   2  1  10.0   5.5
  6250  18.8  65.8  065   2  1  11.1   6.1 |  19.4  66.9  080   2  1  10.6   5.8
  6000  19.6  67.3  060   2  1   9.2   5.0 |  20.2  68.4  070   2  1   9.9   5.4
  5750  20.3  68.5  060   2  1  14.4   7.9 |  21.0  69.8  065   1  1  11.9   6.5
  5500  21.9  71.4  060   2  1  28.7  15.8 |  22.0  71.6  065   1  1  17.0   9.3
________________________________________________________________________________

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 near the old Stapleton
Airport site in Denver, Colorado at

                   North Latitude:  39 deg 46 min 5.016 sec
                   West Longitude: 104 deg 52 min 9.984 sec
                   Elevation: 5285 feet (1611 meters)

and may not be representative of other areas along the Front Range of the
Colorado Rocky Mountains.  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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