Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 081313
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0613 MST Friday, December 8, 2017

This forecast is for Friday, December 8, 2017:

If the trigger temperature of 48.4 F/9.1 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 472 ft/min (2.4 m/s)
   Maximum height of thermals.................. 13717 ft MSL (8420 ft AGL)

Forecast maximum temperature................... 57.0 F/14.3 C
Time of trigger temperature.................... 0945 MST
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................. 11561 ft MSL (6264 ft AGL)
Thermal soaring outlook for Saturday 12/09..... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... Little change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1700 MST)................ Neither
Potential height of wave....................... 38680 ft MSL (33383 ft AGL)
Wave soaring outlook for Saturday 12/09........ Poor

Remarks...

Sunrise/Sunset.................... 07:08:28 / 16:34:45 MST
Total possible sunshine........... 9 hr 26 min 17 sec (566 min 17 sec)
Altitude of sun at 11:51:36 MST... 27.41 degrees

Upper air data from numerical model forecast valid on 12/08/2017 at 0500 MST

Freezing level.................. 8205 ft MSL (2908 ft AGL)
Convective condensation level... 17453 ft MSL (12156 ft AGL)
Lifted condensation level....... 15503 ft MSL (10207 ft AGL)
Lifted index.................... +6.7
K index......................... +7.3

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  -59.5 -75.1   345   12    6   0.0   0.0      M     M       M      M    M
 45000  -59.5 -75.1   350   16    8   0.0   0.0      M     M       M      M    M
 40000  -62.9 -81.2   010   33   17  -2.4  -1.3      M     M       M      M    M
 38000  -62.4 -80.3   010   38   19   5.1   2.8      M     M       M      M    M
 36000  -59.4 -74.9   015   39   20   5.1   2.8      M     M       M      M    M
 34000  -56.1 -69.0   015   39   20   8.5   4.7      M     M       M      M    M
 32000  -51.2 -60.2   015   39   20   8.1   4.5      M     M       M      M    M
 30000  -46.3 -51.3   015   38   20   8.3   4.5   30.2  86.4    12.2      M    M
 29000  -43.8 -46.8   015   38   20   8.3   4.5   29.5  85.2    11.8      M    M
 28000  -40.7 -41.3   010   38   20   8.3   4.6   28.9  83.9    11.5      M    M
 27000  -38.3 -36.9   010   38   20   8.3   4.6   28.4  83.2    11.3      M    M
 26000  -35.8 -32.4   010   36   19   8.3   4.6   27.8  82.0    10.9      M    M
 25000  -33.3 -27.9   010   35   18   8.3   4.6   27.2  81.0    10.6      M    M
 24000  -30.8 -23.4   010   33   17   7.9   4.3   26.8  80.3    10.4      M    M
 23000  -28.6 -19.5   010   32   17   7.3   4.0   25.8  78.5     9.7      M    M
 22000  -26.5 -15.7   010   31   16   7.3   4.0   24.9  76.9     9.0      M    M
 21000  -24.4 -11.9   010   30   16   6.6   3.6   24.1  75.3     8.4      M    M
 20000  -22.5  -8.5   010   30   16   6.4   3.5   22.8  73.1     7.4      M    M
 19500  -21.5  -6.7   005   30   16   6.4   3.5   22.2  72.0     6.9      M    M
 19000  -20.6  -5.1   005   30   16   6.5   3.5   21.7  71.1     6.5      M    M
 18500  -19.6  -3.3   005   31   16   6.6   3.6   21.2  70.1     6.1      M    M
 18000  -18.6  -1.5   005   31   16   6.7   3.7   20.6  69.1     5.6      M    M
 17500  -17.7   0.1   005   31   16   6.7   3.7   20.1  68.2     5.2      M    M
 17000  -16.7   1.9   005   31   16   6.1   3.3   19.5  67.1     4.7      M    M
 16500  -15.8   3.6   005   32   16   6.2   3.4   18.9  66.0     4.1      M    M
 16000  -15.0   5.0   005   32   16   5.1   2.8   18.2  64.8     3.6      M    M
 15500  -14.2   6.4   005   32   17   5.0   2.7   17.4  63.4     2.9      M    M
 15000  -13.5   7.7   005   32   17   4.7   2.6   16.6  62.0     2.2      M    M
 14500  -12.5   9.5   010   33   17   4.4   2.4   15.3  59.6     1.0      M    M
 14000  -11.8  10.8   010   33   17   5.0   2.8   14.5  58.1     0.2      M    M
 13500  -11.0  12.2   010   33   17   5.0   2.7   13.7  56.7    -0.5    647  3.3
 13000  -10.2  13.6   010   32   17   5.4   3.0   13.0  55.3    -1.1    609  3.1
 12500   -9.4  15.1   010   31   16   5.5   3.0   12.3  54.1    -1.8    569  2.9
 12000   -8.6  16.5   010   30   16   4.9   2.7   11.5  52.8    -2.4    531  2.7
 11500   -7.9  17.8   005   29   15   4.6   2.5   10.7  51.3    -3.2    494  2.5
 11000   -7.0  19.4   005   29   15   7.6   4.2   10.1  50.2    -3.8    454  2.3
 10500   -5.9  21.4   360   28   14   8.6   4.7    9.8  49.6    -4.1    404  2.1
 10250   -5.3  22.5   355   28   14   4.8   2.6    9.6  49.4    -4.3    380  1.9
 10000   -5.1  22.8   355   28   14   5.3   2.9    9.1  48.4    -4.8    365  1.9
  9750   -4.4  24.1   355   27   14  11.7   6.4    9.1  48.4    -4.8    337  1.7
  9500   -3.5  25.7   355   27   14  12.5   6.9    9.3  48.7    -4.7    302  1.5
  9250   -2.6  27.3   355   27   14   9.5   5.2    9.4  49.0    -4.5    269  1.4
  9000   -2.0  28.4   350   27   14   7.4   4.0    9.3  48.7    -4.7    245  1.2
  8750   -1.4  29.5   350   26   13   9.1   5.0    9.2  48.5    -4.8    219  1.1
  8500   -0.7  30.7   350   26   13   9.2   5.1    9.1  48.4    -4.9    191  1.0
  8250   -0.1  31.8   345   25   13   8.2   4.5    9.1  48.3    -5.0    164  0.8
  8000    0.5  32.9   345   24   12   7.7   4.2    8.9  48.0    -5.2    139  0.7
  7750    1.1  34.0   340   23   12   9.0   4.9    8.8  47.8    -5.3    114  0.6
  7500    1.8  35.2   340   22   11   7.5   4.1    8.7  47.7    -5.4     87  0.4
  7250    2.2  36.0   335   21   11   4.9   2.7    8.4  47.1    -5.7     67  0.3
  7000    2.6  36.7   335   19   10   6.5   3.6    8.1  46.6    -6.0     47  0.2
  6750    3.0  37.4   330   18    9   2.6   1.5    7.8  46.0    -6.4     27  0.1
  6500    2.9  37.2   325   16    8  -4.4  -2.4    6.9  44.5    -7.2     23  0.1
  6250    2.4  36.3   315   15    8  -6.9  -3.8    5.7  42.3    -8.4     29  0.1
  6000    2.0  35.6   305   14    7  -3.8  -2.1    4.6  40.2    -9.6     35  0.2
  5750    1.8  35.2   300   12    6  -2.0  -1.1    3.7  38.6   -10.5     33  0.2
  5500    1.5  34.7   295    8    4  -6.9  -3.8    2.6  36.7   -11.6     35  0.2

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

           12/08/2017 at 0800 MST          |       12/08/2017 at 1100 MST
                                           |
CAPE...     0.0    LI...       +8.8        | CAPE...     0.0    LI...       +8.8
CINH...     0.0    K Index...  +2.1        | CINH...     0.0    K Index...  +1.4
                                           |
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  350  13  7  -0.9  -0.5 | -60.8 -77.4  340  10  5  -1.4  -0.8
 45000 -62.8 -81.0  355  21 11  -1.0  -0.5 | -63.0 -81.4  345  16  8  -1.5  -0.8
 40000 -62.9 -81.2  360  33 17  -0.0  -0.0 | -63.2 -81.8  360  32 17  -0.0  -0.0
 38000 -61.9 -79.4  005  37 19   4.5   2.5 | -61.9 -79.4  005  37 19   4.8   2.6
 36000 -58.9 -74.0  010  41 21   4.5   2.4 | -59.0 -74.2  010  39 20   4.8   2.7
 34000 -55.7 -68.3  015  43 22   8.5   4.7 | -55.7 -68.3  010  41 21   8.9   4.9
 32000 -50.7 -59.3  015  42 22   8.4   4.6 | -50.5 -58.9  010  40 21   8.6   4.7
 30000 -45.7 -50.3  010  41 21   8.4   4.6 | -45.4 -49.7  005  39 20   8.5   4.7
 29000 -43.1 -45.6  010  40 21   8.4   4.6 | -42.2 -44.0  005  38 19   8.5   4.7
 28000 -40.6 -41.1  010  40 20   8.4   4.6 | -39.6 -39.3  005  37 19   8.6   4.7
 27000 -38.1 -36.6  010  39 20   8.4   4.6 | -37.1 -34.8  005  36 18   7.8   4.3
 26000 -35.6 -32.1  010  38 19   8.4   4.6 | -34.8 -30.6  010  34 17   7.7   4.2
 25000 -33.1 -27.6  010  36 19   8.4   4.6 | -32.5 -26.5  010  32 16   7.7   4.2
 24000 -30.6 -23.1  010  34 18   8.1   4.5 | -30.2 -22.4  010  30 15   7.5   4.1
 23000 -28.3 -18.9  010  33 17   7.5   4.1 | -28.0 -18.4  010  28 15   7.3   4.0
 22000 -26.1 -15.0  010  32 16   7.5   4.1 | -25.8 -14.4  005  27 14   7.3   4.0
 21000 -23.9 -11.0  010  30 16   6.9   3.8 | -23.7 -10.7  005  26 14   6.9   3.8
 20000 -21.9  -7.4  010  31 16   6.7   3.7 | -21.7  -7.1  005  27 14   6.9   3.8
 19500 -20.9  -5.6  010  31 16   6.7   3.7 | -20.6  -5.1  010  27 14   6.9   3.8
 19000 -19.9  -3.8  010  31 16   6.7   3.7 | -19.6  -3.3  010  27 14   6.9   3.8
 18500 -18.9  -2.0  010  31 16   6.5   3.6 | -18.6  -1.5  010  27 14   6.5   3.6
 18000 -17.5   0.5  010  31 16   6.3   3.5 | -17.7   0.1  010  27 14   6.4   3.5
 17500 -16.6   2.1  010  31 16   5.9   3.3 | -16.8   1.8  010  27 14   6.3   3.5
 17000 -15.7   3.7  010  31 16   5.7   3.1 | -15.8   3.6  010  27 14   6.2   3.4
 16500 -14.9   5.2  010  31 16   5.6   3.1 | -14.9   5.2  010  27 14   6.3   3.5
 16000 -14.1   6.6  010  31 16   5.2   2.9 | -14.1   6.6  010  27 14   5.1   2.8
 15500 -13.3   8.1  010  31 16   5.3   2.9 | -13.3   8.1  010  27 14   5.1   2.8
 15000 -12.6   9.3  010  31 16   4.4   2.4 | -12.3   9.9  010  27 14   4.3   2.4
 14500 -11.9  10.6  010  31 16   4.5   2.5 | -11.6  11.1  010  27 14   4.4   2.4
 14000 -11.1  12.0  010  31 16   4.9   2.7 | -10.9  12.4  010  27 14   4.5   2.5
 13500 -10.4  13.3  010  31 16   4.9   2.7 | -10.1  13.8  005  27 14   4.5   2.5
 13000  -9.6  14.7  010  31 16   5.1   2.8 |  -9.4  15.1  005  26 14   5.3   2.9
 12500  -8.8  16.2  010  30 15   5.1   2.8 |  -8.6  16.5  005  26 13   5.1   2.8
 12000  -8.0  17.6  010  29 15   5.4   3.0 |  -7.7  18.1  005  26 13   6.5   3.6
 11500  -7.2  19.0  005  29 15   5.4   3.0 |  -6.8  19.8  360  26 13   6.4   3.5
 11000  -6.3  20.7  005  28 15   7.5   4.1 |  -5.8  21.6  360  26 13   7.5   4.1
 10500  -5.1  22.8  360  28 15   8.4   4.6 |  -4.7  23.5  360  26 13   8.3   4.5
 10250  -4.6  23.7  360  28 15   5.1   2.8 |  -4.1  24.6  360  25 13   3.8   2.1
 10000  -4.3  24.3  360  28 15   4.9   2.7 |  -3.9  25.0  360  25 13   4.8   2.6
  9750  -3.7  25.3  355  28 15  10.6   5.8 |  -3.2  26.2  355  25 13  12.0   6.6
  9500  -2.8  27.0  355  28 14  12.1   6.7 |  -2.3  27.9  355  25 13  11.5   6.3
  9250  -2.0  28.4  355  28 14   8.6   4.7 |  -1.6  29.1  355  25 13   7.8   4.3
  9000  -1.5  29.3  350  28 14   5.9   3.2 |  -1.1  30.0  350  25 13   6.1   3.3
  8750  -1.0  30.2  350  27 14   8.6   4.7 |  -0.6  30.9  350  24 12   9.6   5.3
  8500  -0.3  31.5  350  27 14   9.4   5.2 |   0.2  32.4  350  24 12   9.7   5.3
  8250   0.4  32.7  345  26 13   8.4   4.6 |   0.8  33.4  345  23 12   7.5   4.1
  8000   1.0  33.8  345  25 13   7.8   4.3 |   1.4  34.5  345  21 11   7.4   4.0
  7750   1.6  34.9  345  24 12   9.3   5.1 |   1.9  35.4  340  20 10   7.7   4.2
  7500   2.3  36.1  340  23 12   7.2   3.9 |   2.4  36.3  340  18 10   5.8   3.2
  7250   2.6  36.7  340  21 11   3.9   2.2 |   2.8  37.0  335  17  9   4.3   2.4
  7000   3.0  37.4  335  20 10   5.7   3.1 |   3.1  37.6  335  15  8   4.1   2.2
  6750   3.3  37.9  330  18  9   1.9   1.0 |   3.4  38.1  330  13  7   6.7   3.7
  6500   3.1  37.6  325  16  8  -6.3  -3.5 |   4.0  39.2  325  12  6   6.5   3.6
  6250   2.5  36.5  320  15  8  -9.2  -5.1 |   4.3  39.7  320  10  5   3.1   1.7
  6000   1.8  35.2  310  13  7  -7.2  -4.0 |   4.6  40.3  315   8  4   5.2   2.9
  5750   1.4  34.5  300  11  6  -3.9  -2.1 |   5.1  41.2  310   7  4  11.2   6.1
  5500   1.2  34.2  295   8  4  -1.7  -1.0 |   6.2  43.2  310   7  3  17.8   9.8

           12/08/2017 at 1400 MST          |       12/08/2017 at 1700 MST
                                           |
CAPE...     0.0    LI...       +8.2        | CAPE...     0.0    LI...       +8.0
CINH...     0.0    K Index...  -0.5        | CINH...     0.0    K Index...  -2.4
                                           |
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 -61.3 -78.3  330   6  3  -1.3  -0.7 | -61.4 -78.5  320   7  4  -1.6  -0.9
 45000 -63.2 -81.8  320  13  6  -1.3  -0.7 | -63.8 -82.8  330  17  9  -1.6  -0.9
 40000 -64.2 -83.6  360  31 16  -0.6  -0.3 | -65.5 -85.9  355  31 16  -1.0  -0.6
 38000 -62.5 -80.5  360  35 18   6.3   3.5 | -63.4 -82.1  360  33 17   7.7   4.2
 36000 -58.7 -73.7  360  35 18   6.3   3.5 | -58.8 -73.8  360  32 17   7.7   4.2
 34000 -54.7 -66.5  360  35 18   8.7   4.8 | -54.1 -65.4  355  31 16   8.6   4.7
 32000 -49.5 -57.1  360  34 18   8.6   4.7 | -49.0 -56.2  360  30 16   8.5   4.7
 30000 -44.5 -48.1  005  34 17   8.0   4.4 | -44.0 -47.2  360  29 15   7.7   4.2
 29000 -41.5 -42.7  005  33 17   8.0   4.4 | -41.1 -42.0  360  28 15   7.7   4.2
 28000 -39.1 -38.4  005  32 16   8.0   4.4 | -38.8 -37.8  360  28 14   7.7   4.2
 27000 -36.7 -34.1  005  31 16   7.6   4.2 | -36.5 -33.7  360  27 14   7.3   4.0
 26000 -34.4 -29.9  005  30 16   7.6   4.2 | -34.3 -29.7  360  26 14   7.3   4.0
 25000 -32.1 -25.8  005  29 15   7.6   4.2 | -32.2 -26.0  360  26 13   7.3   4.0
 24000 -29.9 -21.8  005  28 14   7.5   4.1 | -30.0 -22.0  360  26 13   7.4   4.1
 23000 -27.6 -17.7  005  27 14   7.4   4.1 | -27.8 -18.0  005  25 13   7.5   4.1
 22000 -25.4 -13.7  005  27 14   7.4   4.1 | -25.5 -13.9  005  25 13   7.5   4.1
 21000 -23.3  -9.9  005  26 13   6.6   3.6 | -23.3  -9.9  005  25 13   7.3   4.0
 20000 -21.3  -6.3  005  26 13   6.7   3.7 | -21.1  -6.0  005  25 13   7.4   4.0
 19500 -20.3  -4.5  005  25 13   6.7   3.7 | -20.0  -4.0  005  25 13   7.4   4.1
 19000 -19.3  -2.7  005  25 13   6.7   3.7 | -19.0  -2.2  005  25 13   7.7   4.2
 18500 -18.4  -1.1  005  25 13   6.1   3.3 | -18.0  -0.4  005  25 13   3.8   2.1
 18000 -17.5   0.5  005  25 13   5.9   3.2 | -17.6   0.3  005  24 13   3.4   1.8
 17500 -16.7   1.9  005  25 13   6.0   3.3 | -17.1   1.2  005  24 12   4.3   2.3
 17000 -15.8   3.6  005  25 13   6.2   3.4 | -16.3   2.7  005  25 13   6.4   3.5
 16500 -14.9   5.2  005  25 13   6.2   3.4 | -15.3   4.5  005  25 13   6.2   3.4
 16000 -14.0   6.8  005  25 13   5.8   3.2 | -14.2   6.4  005  25 13   8.7   4.8
 15500 -13.1   8.4  005  25 13   5.8   3.2 | -13.0   8.6  360  26 13   8.5   4.7
 15000 -11.9  10.6  005  25 13   5.3   2.9 | -11.8  10.8  360  26 13   6.8   3.7
 14500 -11.1  12.0  005  26 13   5.3   2.9 | -10.3  13.5  005  26 13   6.6   3.6
 14000 -10.2  13.6  360  25 13   5.5   3.0 |  -9.4  15.1  005  26 13   5.0   2.8
 13500  -9.4  15.1  360  25 13   5.5   3.0 |  -8.6  16.5  005  25 13   5.1   2.8
 13000  -8.5  16.7  360  25 13   5.9   3.2 |  -7.7  18.1  360  25 13   6.2   3.4
 12500  -7.6  18.3  360  25 13   5.8   3.2 |  -6.7  19.9  360  24 13   6.0   3.3
 12000  -6.6  20.1  355  24 12   7.0   3.8 |  -5.8  21.6  360  24 12   7.1   3.9
 11500  -5.6  21.9  355  24 12   7.1   3.9 |  -4.7  23.5  360  24 12   7.2   3.9
 11000  -4.6  23.7  355  24 12   6.5   3.6 |  -3.7  25.3  355  23 12   6.4   3.5
 10500  -3.6  25.5  350  23 12   7.2   4.0 |  -2.7  27.1  355  23 12   7.1   3.9
 10250  -3.1  26.4  350  23 12   3.5   1.9 |  -2.3  27.9  355  23 12   3.0   1.6
 10000  -3.0  26.6  345  23 12   5.2   2.8 |  -2.1  28.2  355  23 12   5.3   2.9
  9750  -2.3  27.9  345  22 11  11.1   6.1 |  -1.4  29.5  350  22 11  11.9   6.5
  9500  -1.5  29.3  345  21 11  10.2   5.6 |  -0.6  30.9  350  21 11  10.7   5.8
  9250  -0.8  30.6  340  20 10   7.4   4.1 |   0.1  32.2  345  20 10   7.9   4.3
  9000  -0.4  31.3  340  18  9   5.9   3.2 |   0.6  33.1  345  19 10   6.5   3.6
  8750   0.2  32.4  340  17  9   8.4   4.6 |   1.2  34.2  345  17  9   8.5   4.6
  8500   0.8  33.4  340  15  8   8.3   4.6 |   1.8  35.2  340  16  8   8.2   4.5
  8250   1.3  34.3  335  14  7   7.0   3.8 |   2.3  36.1  340  14  7   7.0   3.9
  8000   1.8  35.2  335  12  6   6.7   3.7 |   2.8  37.0  335  13  7   6.9   3.8
  7750   2.3  36.1  330  11  6   8.0   4.4 |   3.4  38.1  335  12  6   7.4   4.1
  7500   3.0  37.4  330  10  5   9.2   5.1 |   3.9  39.0  330  11  6   6.7   3.7
  7250   3.7  38.7  330   9  5   9.2   5.1 |   4.3  39.7  325  11  5   5.9   3.3
  7000   4.4  39.9  325   9  4   9.1   5.0 |   4.8  40.6  320  10  5   6.0   3.3
  6750   5.0  41.0  325   8  4   9.8   5.4 |   5.2  41.4  315  10  5   6.5   3.6
  6500   5.8  42.4  325   8  4  10.3   5.6 |   5.7  42.3  310  10  5   7.4   4.1
  6250   6.6  43.9  325   8  4   9.6   5.3 |   6.3  43.3  310   9  5   7.9   4.3
  6000   7.3  45.1  325   7  4  11.0   6.0 |   6.9  44.4  310   8  4   6.8   3.7
  5750   8.2  46.8  325   7  4  13.0   7.2 |   7.2  45.0  305   7  4   0.7   0.4
  5500   9.2  48.6  325   6  3  12.8   7.0 |   6.9  44.4  300   5  3  -6.2  -3.4
________________________________________________________________________________

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.

CINH (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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