Soaring Guidance
Issued by NWS Pueblo, CO

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UXUS97 KPUB 201259
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0659 MDT Friday, April 20, 2018

This forecast is for Friday, April 20, 2018:

If the trigger temperature of 54.9 F/12.7 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 9766 ft MSL (2178 ft AGL)

Forecast maximum temperature................... 43.0 F/6.6 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 9086 ft MSL (1497 ft AGL)
Thermal soaring outlook for Saturday 04/21..... Good

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

Remarks...

Effective May 18, 2018 this product will no longer be issued.
If you have any questions, please send email to:
    jennifer.stark@noaa.gov
    paul.wolyn@noaa.gov


Sunrise/Sunset.................... 06:15:10 / 19:41:07 MDT
Total possible sunshine........... 13 hr 25 min 57 sec (805 min 57 sec)
Altitude of sun at 12:58:09 MDT... 62.70 degrees

Upper air data from numerical model forecast valid on 04/20/2018 at 0600 MDT

Freezing level.................. 10119 ft MSL (2531 ft AGL)
Additional freezing level....... 12095 ft MSL (4507 ft AGL)
Convective condensation level... 16543 ft MSL (8955 ft AGL)
Lifted condensation level....... 12541 ft MSL (4953 ft AGL)
Lifted index.................... +8.1
K index......................... +20.6

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  -57.6 -71.7   245   16    8   1.0   0.5      M     M       M      M    M
 45000  -56.2 -69.2   230   25   13  -1.6  -0.9      M     M       M      M    M
 40000  -59.0 -74.2   215   30   15  -1.9  -1.1      M     M       M      M    M
 38000  -58.1 -72.6   215   33   17   4.3   2.3      M     M       M      M    M
 36000  -55.6 -68.1   220   37   19   4.3   2.3      M     M       M      M    M
 34000  -52.6 -62.7   220   40   21   8.0   4.4      M     M       M      M    M
 32000  -47.3 -53.1   220   38   20   7.8   4.3      M     M       M      M    M
 30000  -42.4 -44.3   215   36   19   9.1   5.0   25.8  78.4    15.2      M    M
 29000  -39.7 -39.5   210   35   18   9.1   5.0   25.5  77.9    15.1      M    M
 28000  -37.0 -34.6   210   34   18   9.1   5.0   25.3  77.5    15.2      M    M
 27000  -34.3 -29.7   205   33   17   8.0   4.4   25.1  77.2    15.2      M    M
 26000  -32.0 -25.6   205   33   17   7.8   4.3   24.2  75.6    14.7      M    M
 25000  -29.7 -21.5   200   33   17   7.8   4.3   23.5  74.3    14.2      M    M
 24000  -27.3 -17.1   195   33   17   7.8   4.3   22.9  73.3    13.9      M    M
 23000  -25.0 -13.0   195   33   17   7.8   4.3   22.1  71.9    13.4      M    M
 22000  -22.7  -8.9   195   33   17   7.9   4.3   21.5  70.7    13.0      M    M
 21000  -20.4  -4.7   195   34   17   7.3   4.0   20.9  69.6    12.6      M    M
 20000  -18.3  -0.9   195   34   17   7.1   3.9   19.9  67.8    11.8      M    M
 19500  -17.2   1.0   195   34   17   7.1   3.9   19.4  67.0    11.5      M    M
 19000  -15.6   3.9   195   34   17   7.1   3.9   18.8  65.8    11.0      M    M
 18500  -14.6   5.7   195   34   17   7.0   3.9   18.4  65.0    10.7      M    M
 18000  -13.6   7.5   195   34   17   7.1   3.9   17.9  64.2    10.3      M    M
 17500  -12.6   9.3   195   33   17   7.4   4.1   17.5  63.4     9.9      M    M
 17000  -11.4  11.5   195   33   17   7.9   4.3   17.1  62.8     9.6      M    M
 16500  -10.3  13.5   195   33   17   7.9   4.4   16.8  62.3     9.4      M    M
 16000   -9.1  15.6   200   32   16   8.6   4.7   16.6  61.8     9.1      M    M
 15500   -7.9  17.8   200   31   16   8.5   4.7   16.4  61.5     8.9      M    M
 15000   -6.7  19.9   200   30   15   8.9   4.9   16.2  61.2     8.8      M    M
 14500   -5.4  22.3   200   29   15   9.0   4.9   16.1  60.9     8.6      M    M
 14000   -4.1  24.6   200   27   14   8.7   4.8   16.0  60.7     8.5      M    M
 13500   -2.9  26.8   200   26   13   8.5   4.6   15.7  60.3     8.3      M    M
 13000   -1.6  29.1   200   25   13   8.4   4.6   15.5  60.0     8.2      M    M
 12500   -0.6  30.9   200   24   13   5.1   2.8   15.1  59.1     7.8      M    M
 12000    0.1  32.2   195   23   12   4.5   2.5   14.3  57.8     7.1      M    M
 11750    0.4  32.7   195   23   12   2.9   1.6   13.9  56.9     6.7      M    M
 11500    0.6  33.1   195   22   11   2.3   1.2   13.3  55.9     6.2      M    M
 11250    0.8  33.4   195   22   11   2.9   1.6   12.7  54.9     5.6      M    M
 11000    1.0  33.8   195   21   11   1.3   0.7   12.2  53.9     5.1      M    M
 10750    1.0  33.8   195   20   10  -3.6  -2.0   11.3  52.4     4.4      M    M
 10500    0.6  33.1   190   20   10  -5.5  -3.0   10.2  50.3     3.3      M    M
 10250    0.2  32.4   190   20   10  -5.1  -2.8    9.0  48.3     2.2      M    M
 10000   -0.1  31.8   185   19   10  -4.7  -2.6    7.9  46.2     1.2      M    M
  9750   -0.4  31.3   185   19   10  -4.1  -2.2    6.8  44.3     0.1      M    M
  9500   -0.7  30.7   180   19   10  -2.8  -1.5    5.8  42.4    -0.9    323  1.6
  9250   -0.9  30.4   175   20   10  -6.6  -3.6    4.8  40.6    -1.8    323  1.6
  9000   -1.5  29.3   175   21   11  -5.0  -2.7    3.4  38.2    -3.1    332  1.7
  8750   -1.5  29.3   170   21   11   1.9   1.1    2.7  36.8    -3.9    326  1.7
  8500   -1.3  29.7   165   20   10   2.9   1.6    2.1  35.8    -4.5    313  1.6
  8250   -1.2  29.8   165   20   10   0.2   0.1    1.5  34.8    -5.0    301  1.5
  8000   -1.2  29.8   160   18    9  -0.8  -0.4    0.7  33.3    -5.9    296  1.5
  7750   -1.1  30.0   160   13    7   5.5   3.0    0.1  32.2    -6.5    284  1.4
  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 * * * * * *

           04/20/2018 at 0900 MDT          |       04/20/2018 at 1200 MDT
                                           |
CAPE...     0.0    LI...       -1.2        | CAPE...   +19.6    LI...       -0.9
CINH...     0.0    K Index... +23.5        | CINH...     0.0    K Index... +23.0
                                           |
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 -57.2 -71.0  245  16  8   2.4   1.3 | -56.5 -69.7  240  15  8   2.9   1.6
 45000 -53.7 -64.7  230  25 13  -0.5  -0.3 | -52.3 -62.1  240  20 10   0.5   0.3
 40000 -55.4 -67.7  205  24 12  -1.1  -0.6 | -51.9 -61.4  195  23 12   0.3   0.2
 38000 -54.9 -66.8  200  28 14   2.9   1.6 | -51.0 -59.8  190  27 14   2.8   1.6
 36000 -53.2 -63.8  205  35 18   2.9   1.6 | -49.1 -56.4  195  31 16   2.8   1.6
 34000 -50.8 -59.4  210  42 21   6.0   3.3 | -47.3 -53.1  195  35 18   3.2   1.7
 32000 -47.2 -53.0  205  43 22   6.1   3.3 | -45.4 -49.7  195  41 21   3.2   1.7
 30000 -43.2 -45.8  200  43 22   8.3   4.6 | -43.3 -45.9  190  46 24   6.1   3.3
 29000 -40.7 -41.3  195  42 21   8.4   4.6 | -41.6 -42.9  190  46 24   5.8   3.2
 28000 -38.2 -36.8  190  41 21   8.4   4.6 | -39.8 -39.6  185  46 24   5.9   3.2
 27000 -35.7 -32.3  190  40 20   8.2   4.5 | -38.1 -36.6  185  47 24   5.9   3.2
 26000 -33.3 -27.9  185  39 20   7.9   4.3 | -35.7 -32.3  180  46 24   8.4   4.6
 25000 -30.9 -23.6  185  39 20   7.9   4.3 | -33.2 -27.8  180  45 23   8.4   4.6
 24000 -28.6 -19.5  185  39 20   7.9   4.3 | -30.7 -23.3  180  45 23   8.5   4.7
 23000 -26.4 -15.5  185  38 20   7.1   3.9 | -28.4 -19.1  180  44 22   7.4   4.0
 22000 -24.3 -11.7  185  37 19   7.2   3.9 | -26.2 -15.2  180  43 22   7.4   4.0
 21000 -22.2  -8.0  185  36 19   7.2   4.0 | -23.5 -10.3  185  41 21   7.6   4.2
 20000 -19.5  -3.1  185  36 18   7.3   4.0 | -21.2  -6.2  185  38 19   7.7   4.2
 19500 -18.4  -1.1  185  35 18   7.4   4.0 | -20.1  -4.2  190  36 18   7.7   4.2
 19000 -17.3   0.9  185  35 18   7.4   4.0 | -19.0  -2.2  190  34 17   7.7   4.2
 18500 -16.2   2.8  185  34 18   7.3   4.0 | -17.8  -0.0  190  32 16   7.9   4.3
 18000 -15.2   4.6  185  32 16   7.3   4.0 | -16.7   1.9  190  29 15   8.0   4.4
 17500 -14.1   6.6  180  29 15   7.3   4.0 | -15.5   4.1  190  26 13   8.1   4.4
 17000 -13.0   8.6  180  27 14   7.3   4.0 | -14.4   6.1  190  24 12   7.2   3.9
 16500 -12.0  10.4  180  26 13   7.3   4.0 | -13.3   8.1  185  22 11   7.2   4.0
 16000 -10.9  12.4  180  24 12   7.6   4.2 | -12.2  10.0  185  21 11   8.0   4.4
 15500  -9.8  14.4  180  23 12   7.7   4.2 | -11.0  12.2  180  20 10   8.2   4.5
 15000  -8.7  16.3  185  21 11   7.8   4.3 |  -9.8  14.4  180  20 10   7.6   4.2
 14500  -7.5  18.5  185  21 11   7.9   4.4 |  -8.8  16.2  175  19 10   6.7   3.7
 14000  -6.4  20.5  190  20 10   7.8   4.3 |  -7.9  17.8  175  18  9   6.8   3.7
 13500  -5.3  22.5  190  20 10   7.5   4.1 |  -6.9  19.6  175  16  8   7.3   4.0
 13000  -4.2  24.4  190  20 11   8.4   4.6 |  -5.8  21.6  175  15  8   7.6   4.2
 12500  -3.0  26.6  190  20 10   6.4   3.5 |  -4.7  23.5  175  14  7   5.2   2.9
 12000  -2.2  28.0  195  19 10   5.5   3.0 |  -4.2  24.4  175  13  7   4.0   2.2
 11750  -1.8  28.8  195  19 10   3.5   1.9 |  -3.9  25.0  175  13  7   2.7   1.5
 11500  -1.7  28.9  195  18  9   2.3   1.3 |  -3.8  25.2  175  12  6   1.3   0.7
 11250  -1.5  29.3  195  17  9   2.8   1.5 |  -3.7  25.3  175  12  6   0.8   0.5
 11000  -1.3  29.7  195  16  8   2.3   1.3 |  -3.7  25.3  175  11  6   0.8   0.5
 10750  -1.2  29.8  195  15  8  -1.3  -0.7 |  -3.6  25.5  175  11  6  -0.7  -0.4
 10500  -1.4  29.5  195  14  7  -3.5  -1.9 |  -3.7  25.3  175  11  6  -1.8  -1.0
 10250  -1.6  29.1  190  13  7  -3.1  -1.7 |  -3.9  25.0  170  11  6  -2.2  -1.2
 10000  -1.9  28.6  190  13  6  -3.8  -2.1 |  -4.0  24.8  170  12  6  -2.5  -1.4
  9750  -2.1  28.2  185  12  6  -4.7  -2.6 |  -4.1  24.6  170  12  6   1.4   0.8
  9500  -2.5  27.5  180  13  7  -4.6  -2.5 |  -3.9  25.0  165  13  7   3.8   2.1
  9250  -2.8  27.0  175  14  7  -6.2  -3.4 |  -3.6  25.5  160  13  7   3.2   1.8
  9000  -3.2  26.2  170  15  8  -2.1  -1.1 |  -3.3  26.1  160  14  7   5.7   3.1
  8750  -3.0  26.6  170  15  8   5.5   3.0 |  -2.8  27.0  160  14  7   8.2   4.5
  8500  -2.6  27.3  165  14  7   6.5   3.6 |  -2.2  28.0  155  13  7   9.1   5.0
  8250  -2.1  28.2  165  13  7   5.4   3.0 |  -1.6  29.1  155  12  6   7.3   4.0
  8000  -1.5  29.3  160  13  7  12.2   6.7 |  -1.0  30.2  155  11  6  13.3   7.3
  7750  -0.1  31.8  160  11  5  25.8  14.1 |   0.6  33.1  155  10  5  28.1  15.4
  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

           04/20/2018 at 1500 MDT          |       04/20/2018 at 1800 MDT
                                           |
CAPE...   +16.3    LI...       -0.1        | CAPE...   +35.6    LI...       +0.4
CINH...    -1.2    K Index... +16.8        | CINH...    -1.4    K Index... +11.9
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -55.8 -68.4  250  13  7   2.4   1.3 | -55.5 -67.9  265  10  5   2.5   1.4
 45000 -52.2 -62.0  255  12  6   2.1   1.2 | -51.8 -61.2  245   7  4   2.6   1.4
 40000 -49.0 -56.2  200  16  8   2.1   1.2 | -47.8 -54.0  215   9  5   2.6   1.5
 38000 -47.8 -54.0  190  19 10   1.9   1.0 | -46.2 -51.2  205  10  5   2.7   1.5
 36000 -46.7 -52.1  185  21 11   1.9   1.0 | -44.3 -47.7  190  12  6   2.7   1.5
 34000 -45.4 -49.7  180  23 12   2.3   1.3 | -42.9 -45.2  180  13  7  -0.4  -0.2
 32000 -44.0 -47.2  180  28 15   2.3   1.3 | -43.4 -46.1  175   8  4  -0.8  -0.4
 30000 -42.5 -44.5  180  33 17   3.5   1.9 | -43.8 -46.8  155   4  2   1.8   1.0
 29000 -41.5 -42.7  180  34 17   3.7   2.0 | -42.8 -45.0  045   2  1   3.2   1.8
 28000 -40.4 -40.7  180  34 18   3.7   2.0 | -41.9 -43.4  010   6  3   3.2   1.8
 27000 -39.3 -38.7  185  34 18   3.4   1.8 | -40.9 -41.6  360  10  5   3.0   1.6
 26000 -37.4 -35.3  185  33 17   7.3   4.0 | -39.0 -38.2  005  11  5   8.4   4.6
 25000 -35.2 -31.4  185  31 16   7.4   4.0 | -36.4 -33.5  015   8  4   8.5   4.7
 24000 -33.0 -27.4  190  29 15   7.3   4.0 | -33.9 -29.0  030   6  3   8.5   4.7
 23000 -30.7 -23.3  190  27 14   8.2   4.5 | -31.5 -24.7  055   4  2   7.5   4.1
 22000 -28.2 -18.8  190  25 13   8.2   4.5 | -29.3 -20.7  095   3  2   7.5   4.1
 21000 -25.7 -14.3  190  23 12   8.2   4.5 | -27.0 -16.6  130   4  2   7.3   4.0
 20000 -23.2  -9.8  190  22 11   8.6   4.7 | -24.6 -12.3  145   5  3   8.4   4.6
 19500 -21.3  -6.3  190  21 11   8.6   4.7 | -22.7  -8.9  150   6  3   8.4   4.6
 19000 -20.0  -4.0  195  20 10   8.6   4.7 | -21.4  -6.5  155   7  3   8.4   4.6
 18500 -18.7  -1.7  195  19 10   8.1   4.5 | -20.2  -4.4  155   7  4   8.2   4.5
 18000 -17.6   0.3  195  18  9   7.2   4.0 | -19.0  -2.2  165   7  4   7.6   4.2
 17500 -16.6   2.1  195  17  9   7.3   4.0 | -17.9  -0.2  175   7  4   7.6   4.2
 17000 -15.6   3.9  195  16  8   6.4   3.5 | -16.7   1.9  180   7  4   7.8   4.3
 16500 -14.6   5.7  195  15  8   6.5   3.6 | -15.6   3.9  190   8  4   7.8   4.3
 16000 -13.6   7.5  195  15  7   7.1   3.9 | -14.4   6.1  200   8  4   7.3   4.0
 15500 -12.6   9.3  190  14  7   7.5   4.1 | -13.4   7.9  210   8  4   7.1   3.9
 15000 -11.5  11.3  185  13  7   7.6   4.2 | -12.4   9.7  215   9  5   7.0   3.9
 14500 -10.4  13.3  180  13  6   7.9   4.3 | -11.3  11.7  220  10  5   7.0   3.8
 14000  -9.2  15.4  180  13  6   7.8   4.3 | -10.3  13.5  230  10  5   7.0   3.8
 13500  -8.1  17.4  175  13  7   7.4   4.1 |  -9.3  15.3  230  11  6   7.0   3.9
 13000  -7.1  19.2  175  14  7   7.6   4.2 |  -8.3  17.1  235  12  6   7.2   3.9
 12500  -6.1  21.0  170  14  7   5.3   2.9 |  -7.2  19.0  230  13  6   6.4   3.5
 12000  -5.4  22.3  170  15  8   5.4   3.0 |  -6.6  20.1  225  13  7   5.5   3.0
 11750  -5.0  23.0  165  16  8   3.9   2.1 |  -6.2  20.8  225  13  7   3.4   1.9
 11500  -4.8  23.4  165  16  8   2.9   1.6 |  -6.1  21.0  220  13  7   3.8   2.1
 11250  -4.6  23.7  165  16  8   3.8   2.1 |  -5.6  21.9  215  13  7   7.3   4.0
 11000  -4.3  24.3  160  16  8   4.0   2.2 |  -5.1  22.8  205  13  7   8.1   4.4
 10750  -4.0  24.8  160  16  8   3.1   1.7 |  -4.5  23.9  200  14  7   5.8   3.2
 10500  -3.8  25.2  155  17  9   2.1   1.1 |  -4.3  24.3  190  14  7   3.3   1.8
 10250  -3.7  25.3  155  17  9   2.8   1.5 |  -4.0  24.8  185  15  8   5.8   3.2
 10000  -3.4  25.9  150  17  9   3.2   1.8 |  -3.4  25.9  180  15  8   7.4   4.1
  9750  -3.2  26.2  150  17  9   2.0   1.1 |  -3.0  26.6  175  16  8   5.6   3.1
  9500  -3.1  26.4  145  17  9   0.8   0.5 |  -2.6  27.3  170  16  8   4.5   2.5
  9250  -3.1  26.4  145  17  9   2.0   1.1 |  -2.3  27.9  165  16  8   5.7   3.1
  9000  -2.8  27.0  140  17  9   5.5   3.0 |  -1.8  28.8  160  16  8   7.4   4.1
  8750  -2.3  27.9  135  16  8   7.6   4.2 |  -1.2  29.8  160  15  8   7.1   3.9
  8500  -1.7  28.9  135  15  8   7.7   4.2 |  -0.8  30.6  155  14  7   6.3   3.4
  8250  -1.2  29.8  135  14  7   7.1   3.9 |  -0.3  31.5  155  13  7   7.4   4.1
  8000  -0.6  30.9  130  13  7  11.9   6.5 |   0.3  32.5  150  12  6   9.4   5.1
  7750   0.6  33.1  130  10  5  21.7  11.9 |   1.0  33.8  145   9  5   9.6   5.2
  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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