Soaring Guidance
Issued by NWS Pueblo, CO

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000
UXUS97 KPUB 151205
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0605 MDT Sunday, April 15, 2018

This forecast is for Sunday, April 15, 2018:

If the trigger temperature of 42.6 F/5.9 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 971 ft/min (4.9 m/s)
   Maximum height of thermals.................. 19768 ft MSL (12160 ft AGL)

Forecast maximum temperature................... 59.0 F/15.5 C
Time of trigger temperature.................... 0930 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 18126 ft MSL (10518 ft AGL)
Thermal soaring outlook for Monday 04/16....... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:22:15 / 19:36:16 MDT
Total possible sunshine........... 13 hr 14 min 0 sec (794 min 0 sec)
Altitude of sun at 12:59:16 MDT... 60.96 degrees

Upper air data from numerical model forecast valid on 04/15/2018 at 0600 MDT

Freezing level.................. 7812 ft MSL (204 ft AGL)
Additional freezing level....... 8773 ft MSL (1165 ft AGL)
Convective condensation level... 13705 ft MSL (6097 ft AGL)
Lifted condensation level....... 16914 ft MSL (9306 ft AGL)
Lifted index.................... +2.2
K index......................... +8.7

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  -60.8 -77.4   295   25   13   2.9   1.6      M     M       M      M    M
 45000  -56.2 -69.2   300   35   18   3.9   2.1      M     M       M      M    M
 40000  -50.4 -58.7   300   48   25   3.9   2.1      M     M       M      M    M
 38000  -49.3 -56.7   305   49   25   0.3   0.2      M     M       M      M    M
 36000  -49.1 -56.4   305   48   25   0.3   0.2      M     M       M      M    M
 34000  -47.9 -54.2   310   48   25   6.3   3.5      M     M       M      M    M
 32000  -44.0 -47.2   310   47   24   6.4   3.5      M     M       M      M    M
 30000  -40.2 -40.4   310   46   24   6.4   3.5   29.7  85.5    11.3      M    M
 29000  -38.3 -36.9   310   44   23   6.4   3.5   28.4  83.0    10.4      M    M
 28000  -36.4 -33.5   310   42   22   6.4   3.5   27.1  80.8     9.5      M    M
 27000  -34.4 -29.9   310   40   21   6.1   3.3   26.0  78.8     8.8      M    M
 26000  -32.7 -26.9   315   38   20   5.6   3.1   24.3  75.8     7.5      M    M
 25000  -31.1 -24.0   315   36   18   5.6   3.1   22.8  73.1     6.4      M    M
 24000  -29.4 -20.9   315   34   17   5.7   3.1   21.4  70.6     5.3      M    M
 23000  -27.5 -17.5   315   32   16   6.6   3.6   20.2  68.3     4.3      M    M
 22000  -25.5 -13.9   315   30   15   6.6   3.6   19.0  66.2     3.4      M    M
 21000  -23.5 -10.3   320   28   14   5.4   2.9   18.0  64.4     2.5      M    M
 20000  -22.1  -7.8   315   24   13   3.8   2.1   15.4  59.6     0.2      M    M
 19500  -21.6  -6.9   315   23   12   3.8   2.1   14.3  57.8    -0.7   1048  5.3
 19000  -21.0  -5.8   310   21   11   3.8   2.1   13.4  56.1    -1.5   1016  5.2
 18500  -20.5  -4.9   310   20   10   3.7   2.0   12.4  54.3    -2.4    985  5.0
 18000  -19.9  -3.8   315   20   11   3.8   2.1   11.4  52.4    -3.4    954  4.8
 17500  -19.4  -2.9   320   21   11   4.8   2.6   10.4  50.7    -4.3    923  4.7
 17000  -18.4  -1.1   320   20   10   7.1   3.9    9.8  49.7    -4.8    880  4.5
 16500  -17.4   0.7   320   20   10   7.0   3.9    9.4  48.9    -5.3    834  4.2
 16000  -16.3   2.7   320   19   10   7.6   4.2    9.0  48.2    -5.7    786  4.0
 15500  -15.2   4.6   325   19   10   7.5   4.1    8.6  47.5    -6.1    738  3.8
 15000  -14.1   6.6   325   19   10   7.4   4.1    8.3  46.9    -6.5    691  3.5
 14500  -13.0   8.6   325   18    9   7.4   4.1    7.9  46.2    -6.9    643  3.3
 14000  -11.9  10.6   325   18    9   8.0   4.4    7.5  45.5    -7.3    595  3.0
 13500  -10.7  12.7   325   18    9   8.3   4.5    7.3  45.1    -7.6    544  2.8
 13000   -9.5  14.9   325   17    9   8.8   4.8    7.1  44.7    -7.8    492  2.5
 12500   -8.2  17.2   325   17    9   7.9   4.3    6.9  44.4    -8.0    439  2.2
 12000   -7.1  19.2   330   17    9   7.7   4.2    6.6  43.8    -8.4    391  2.0
 11750   -6.5  20.3   330   17    9   7.9   4.4    6.4  43.5    -8.6    366  1.9
 11500   -5.9  21.4   330   16    8   8.1   4.4    6.3  43.3    -8.8    341  1.7
 11250   -5.3  22.5   330   16    8   8.9   4.9    6.2  43.1    -8.9    315  1.6
 11000   -4.6  23.7   330   16    8   7.7   4.2    6.1  42.9    -9.0    289  1.5
 10750   -4.1  24.6   330   15    8   6.6   3.6    5.8  42.5    -9.3    267  1.4
 10500   -3.7  25.3   330   15    8   6.6   3.6    5.6  42.1    -9.6    245  1.2
 10250   -3.2  26.2   330   15    8   7.6   4.2    5.4  41.7    -9.8    223  1.1
 10000   -2.6  27.3   330   14    7   7.0   3.9    5.3  41.5   -10.0    198  1.0
  9750   -2.2  28.0   330   13    6   5.5   3.0    4.9  40.9   -10.3    178  0.9
  9500   -1.7  28.9   330   11    6   5.8   3.2    4.6  40.4   -10.7    158  0.8
  9250   -1.3  29.7   330   10    5   6.3   3.5    4.3  39.8   -11.0    137  0.7
  9000   -0.8  30.6   330    9    5   7.8   4.3    4.2  39.5   -11.2    114  0.6
  8750   -0.2  31.6   330    8    4   7.9   4.3    4.0  39.2   -11.4     88  0.4
  8500    0.4  32.7   325    6    3   8.5   4.7    3.9  39.0   -11.5     63  0.3
  8250    1.0  33.8   320    5    2   5.9   3.2    3.7  38.7   -11.7     37  0.2
  8000    1.1  34.0   320    4    2  -6.2  -3.4    3.1  37.5   -12.3     28  0.1
  7750    0.2  32.4   310    3    2 -18.2 -10.0    1.3  34.4   -14.1     49  0.2
  7500      M     M     M    M    M     M     M      M     M       M      M    M
  7250      M     M     M    M    M     M     M      M     M       M      M    M
  7000      M     M     M    M    M     M     M      M     M       M      M    M
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           04/15/2018 at 0900 MDT          |       04/15/2018 at 1200 MDT
                                           |
CAPE...     0.0    LI...       +3.9        | CAPE...    +6.4    LI...       +3.1
CINH...     0.0    K Index...  +5.8        | CINH...    -0.0    K Index...  +6.1
                                           |
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 -61.2 -78.2  290  26 13   2.9   1.6 | -61.6 -78.9  280  26 14   3.0   1.6
 45000 -56.7 -70.1  295  35 18   4.4   2.4 | -56.9 -70.4  285  34 18   5.3   2.9
 40000 -50.2 -58.4  290  44 22   4.4   2.4 | -49.1 -56.4  285  39 20   5.3   2.9
 38000 -49.3 -56.7  295  45 23  -0.3  -0.2 | -48.5 -55.3  290  40 20  -1.4  -0.8
 36000 -49.5 -57.1  300  45 23  -0.3  -0.2 | -49.3 -56.7  290  40 21  -1.4  -0.8
 34000 -48.4 -55.1  305  46 23   6.3   3.4 | -48.7 -55.7  295  41 21   6.1   3.4
 32000 -44.6 -48.3  305  46 24   6.4   3.5 | -45.0 -49.0  295  42 22   6.2   3.4
 30000 -40.7 -41.3  305  46 24   6.9   3.8 | -40.9 -41.6  295  41 21   7.9   4.4
 29000 -38.6 -37.5  305  43 22   6.9   3.8 | -38.6 -37.5  295  38 20   8.0   4.4
 28000 -36.6 -33.9  305  41 21   6.9   3.8 | -36.2 -33.2  295  36 19   8.0   4.4
 27000 -34.5 -30.1  305  38 20   6.4   3.5 | -33.8 -28.8  300  34 17   6.6   3.6
 26000 -32.7 -26.9  305  36 18   6.0   3.3 | -32.1 -25.8  300  33 17   5.7   3.1
 25000 -30.9 -23.6  305  33 17   6.0   3.3 | -30.4 -22.7  300  32 17   5.7   3.1
 24000 -29.1 -20.4  305  31 16   6.1   3.3 | -28.7 -19.7  300  31 16   5.9   3.2
 23000 -27.2 -17.0  310  28 15   6.4   3.5 | -26.8 -16.2  300  30 15   6.3   3.5
 22000 -25.3 -13.5  310  26 13   6.4   3.5 | -24.4 -11.9  305  27 14   6.3   3.5
 21000 -22.9  -9.2  310  23 12   6.9   3.8 | -22.5  -8.5  305  25 13   7.0   3.8
 20000 -20.9  -5.6  315  22 11   6.8   3.7 | -20.4  -4.7  305  23 12   6.9   3.8
 19500 -19.9  -3.8  315  22 11   6.9   3.8 | -19.4  -2.9  305  22 12   6.9   3.8
 19000 -18.9  -2.0  315  21 11   7.1   3.9 | -18.4  -1.1  310  21 11   7.1   3.9
 18500 -18.0  -0.4  315  20 11   3.7   2.0 | -17.4   0.7  310  21 11   5.4   2.9
 18000 -17.5   0.5  315  20 10   3.5   1.9 | -16.6   2.1  310  20 10   5.4   3.0
 17500 -17.0   1.4  315  20 10   3.4   1.9 | -15.8   3.6  310  20 10   5.3   2.9
 17000 -16.5   2.3  310  19 10   3.2   1.8 | -15.1   4.8  310  19 10   5.2   2.8
 16500 -16.1   3.0  310  18  9   3.2   1.7 | -14.3   6.3  315  19 10   5.2   2.8
 16000 -15.4   4.3  315  17  9   6.1   3.4 | -13.5   7.7  315  18  9   5.2   2.9
 15500 -14.5   5.9  315  17  9   5.8   3.2 | -12.8   9.0  315  17  9   5.2   2.9
 15000 -13.6   7.5  315  17  9   7.4   4.1 | -12.0  10.4  310  17  9   5.4   3.0
 14500 -12.5   9.5  315  16  8   7.5   4.1 | -11.2  11.8  310  16  8   5.4   3.0
 14000 -11.4  11.5  320  16  8   7.3   4.0 | -10.4  13.3  310  15  7   6.7   3.7
 13500 -10.4  13.3  320  15  8   7.3   4.0 |  -9.4  15.1  305  13  7   7.2   3.9
 13000  -9.3  15.3  325  14  7   7.8   4.3 |  -8.3  17.1  305  12  6   7.3   4.0
 12500  -8.2  17.2  325  13  7   6.8   3.7 |  -7.3  18.9  305  11  5   7.1   3.9
 12000  -7.2  19.0  325  13  6   6.6   3.6 |  -6.3  20.7  305   9  5   6.6   3.6
 11750  -6.8  19.8  330  12  6   6.7   3.7 |  -5.8  21.6  305   8  4   5.8   3.2
 11500  -6.3  20.7  330  11  6   6.8   3.7 |  -5.4  22.3  305   7  4   7.2   4.0
 11250  -5.7  21.7  330  11  6   7.3   4.0 |  -4.8  23.4  305   6  3   9.4   5.2
 11000  -5.2  22.6  335  10  5   6.4   3.5 |  -4.1  24.6  310   5  3   9.2   5.0
 10750  -4.8  23.4  335  10  5   5.7   3.1 |  -3.4  25.9  310   4  2   8.9   4.9
 10500  -4.4  24.1  340  10  5   5.3   2.9 |  -2.7  27.1  315   3  2   8.5   4.7
 10250  -4.0  24.8  340   9  5   7.4   4.0 |  -2.1  28.2  325   2  1  10.8   5.9
 10000  -3.3  26.1  340   9  4   8.4   4.6 |  -1.2  29.8  330   2  1  11.4   6.3
  9750  -2.8  27.0  345   8  4   7.0   3.8 |  -0.4  31.3  335   2  1   9.6   5.3
  9500  -2.2  28.0  345   8  4   7.5   4.1 |   0.3  32.5  335   2  1  10.4   5.7
  9250  -1.7  28.9  345   7  4   6.8   3.7 |   1.1  34.0  340   2  1   9.1   5.0
  9000  -1.2  29.8  345   7  4   8.4   4.6 |   1.7  35.1  340   2  1   9.4   5.2
  8750  -0.4  31.3  340   6  3  10.3   5.7 |   2.5  36.5  345   2  1  10.8   5.9
  8500   0.3  32.5  340   6  3   9.7   5.3 |   3.3  37.9  350   2  1  10.3   5.7
  8250   1.1  34.0  340   5  3  10.3   5.7 |   4.1  39.4  355   2  1  11.0   6.0
  8000   1.9  35.4  340   4  2  14.1   7.8 |   5.1  41.2  355   2  1  18.1   9.9
  7750   3.2  37.8  345   4  2  19.0  10.4 |   6.8  44.2  360   2  1  27.9  15.3
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/15/2018 at 1500 MDT          |       04/15/2018 at 1800 MDT
                                           |
CAPE...    +4.1    LI...       +0.2        | CAPE...    +0.4    LI...       -0.1
CINH...    -5.1    K Index... +15.4        | CINH...    -8.4    K Index... +15.6
                                           |
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 -62.0 -79.6  270  29 15   2.7   1.5 | -62.4 -80.3  265  28 14   3.0   1.6
 45000 -57.7 -71.9  280  35 18   5.1   2.8 | -57.7 -71.9  270  32 17   4.8   2.7
 40000 -50.1 -58.2  280  37 19   5.1   2.8 | -50.4 -58.7  280  34 18   4.8   2.6
 38000 -49.4 -56.9  285  37 19  -0.9  -0.5 | -49.7 -57.5  280  35 18  -0.6  -0.3
 36000 -49.9 -57.8  285  36 18  -0.9  -0.5 | -50.0 -58.0  285  36 18  -0.6  -0.3
 34000 -48.9 -56.0  285  36 18   6.7   3.7 | -48.7 -55.7  290  37 19   7.0   3.8
 32000 -44.8 -48.6  290  37 19   6.7   3.7 | -44.6 -48.3  290  40 21   7.0   3.8
 30000 -40.5 -40.9  290  38 19   8.0   4.4 | -40.2 -40.4  290  41 21   8.0   4.4
 29000 -38.2 -36.8  290  36 19   8.0   4.4 | -37.8 -36.0  290  39 20   8.0   4.4
 28000 -35.8 -32.4  295  35 18   8.0   4.4 | -35.4 -31.7  290  38 19   8.0   4.4
 27000 -33.4 -28.1  295  34 17   7.2   3.9 | -33.1 -27.6  290  36 19   7.5   4.1
 26000 -31.3 -24.3  295  33 17   7.0   3.8 | -30.9 -23.6  290  34 17   7.4   4.1
 25000 -29.3 -20.7  295  32 16   7.0   3.8 | -28.7 -19.7  290  31 16   7.4   4.1
 24000 -27.2 -17.0  295  31 16   6.4   3.5 | -26.5 -15.7  290  29 15   6.6   3.6
 23000 -25.2 -13.4  295  29 15   5.2   2.9 | -24.4 -11.9  290  27 14   5.4   3.0
 22000 -23.6 -10.5  295  27 14   5.2   2.9 | -22.8  -9.0  290  26 14   5.4   3.0
 21000 -22.1  -7.8  300  25 13   5.5   3.0 | -21.2  -6.2  285  25 13   5.1   2.8
 20000 -20.4  -4.7  295  24 12   5.5   3.0 | -19.7  -3.5  285  23 12   5.1   2.8
 19500 -19.6  -3.3  295  23 12   5.5   3.0 | -19.0  -2.2  285  22 11   5.1   2.8
 19000 -18.8  -1.8  295  22 12   5.4   2.9 | -18.2  -0.8  285  21 11   4.9   2.7
 18500 -17.9  -0.2  295  22 11   6.8   3.7 | -17.3   0.9  285  20 10   7.2   3.9
 18000 -17.0   1.4  295  21 11   6.7   3.7 | -16.3   2.7  280  19 10   7.0   3.8
 17500 -16.0   3.2  290  20 10   7.4   4.0 | -15.3   4.5  280  18  9   7.3   4.0
 17000 -14.8   5.4  290  18  9   7.9   4.3 | -14.2   6.4  275  17  9   7.5   4.1
 16500 -13.7   7.3  285  16  8   8.0   4.4 | -13.1   8.4  275  15  8   7.8   4.3
 16000 -12.5   9.5  280  15  8   8.1   4.4 | -11.9  10.6  270  14  7   9.0   4.9
 15500 -11.4  11.5  275  13  7   8.3   4.6 | -10.6  12.9  270  13  7   8.9   4.9
 15000 -10.3  13.5  275  11  6   5.8   3.2 |  -9.2  15.4  270  12  6   9.2   5.0
 14500  -9.5  14.9  270  10  5   5.8   3.2 |  -7.8  18.0  270  12  6   9.2   5.1
 14000  -8.6  16.5  265   8  4   6.8   3.8 |  -6.5  20.3  270  11  6   8.7   4.8
 13500  -7.5  18.5  260   7  4   7.1   3.9 |  -5.2  22.6  265  10  5   8.6   4.7
 13000  -6.5  20.3  250   5  3   6.9   3.8 |  -4.0  24.8  255   9  4   9.0   4.9
 12500  -5.6  21.9  235   4  2   5.6   3.1 |  -2.8  27.0  245   8  4   5.6   3.1
 12000  -4.7  23.5  210   3  1   6.3   3.4 |  -2.0  28.4  240   8  4   4.9   2.7
 11750  -4.2  24.4  195   3  1   6.9   3.8 |  -1.7  28.9  235   8  4   3.7   2.0
 11500  -3.7  25.3  185   3  2   7.3   4.0 |  -1.4  29.5  230   7  4   5.2   2.8
 11250  -3.1  26.4  175   3  2   8.3   4.6 |  -0.9  30.4  225   7  4   6.7   3.7
 11000  -2.5  27.5  165   4  2   8.2   4.5 |  -0.5  31.1  215   7  4   6.0   3.3
 10750  -1.9  28.6  165   4  2   8.2   4.5 |  -0.0  32.0  210   7  3   5.5   3.0
 10500  -1.3  29.7  165   4  2   7.9   4.3 |   0.4  32.7  200   7  3   5.5   3.0
 10250  -0.7  30.7  160   4  2   9.8   5.4 |   0.8  33.4  195   7  3   6.7   3.7
 10000   0.1  32.2  160   4  2  10.4   5.7 |   1.4  34.5  185   7  3   8.7   4.8
  9750   0.8  33.4  155   4  2   9.2   5.1 |   2.1  35.8  185   7  3   9.4   5.1
  9500   1.5  34.7  155   5  2   9.3   5.1 |   2.7  36.9  180   7  3   8.9   4.9
  9250   2.2  36.0  155   5  2  10.3   5.6 |   3.4  38.1  175   7  3  10.2   5.6
  9000   3.1  37.6  155   5  2  10.7   5.8 |   4.2  39.6  170   7  3  10.5   5.7
  8750   3.8  38.8  155   5  2  10.0   5.5 |   5.0  41.0  170   7  3   9.4   5.2
  8500   4.6  40.3  155   5  3   9.8   5.4 |   5.7  42.3  165   7  3   9.5   5.2
  8250   5.3  41.5  155   5  3  11.3   6.2 |   6.4  43.5  165   7  3  10.2   5.6
  8000   6.3  43.3  155   5  3  16.0   8.8 |   7.3  45.1  165   7  3  13.1   7.2
  7750   9.0  48.2  150   4  2  15.3   8.4 |   8.3  46.9  165   6  3  15.2   8.3
  7500     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     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).  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 Air Force Academy
in Colorado Springs, Colorado at

                   North Latitude:  38 deg 58 min 48.000 sec
                   West Longitude: 104 deg 49 min 12.000 sec
                   Elevation: 6572 feet (2003 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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