Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 241347
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0646 MST Friday, January 24, 2020

This forecast is for Friday, January 24, 2020:

If the trigger temperature of 49.5 F/9.7 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 447 ft/min (2.3 m/s)
   Maximum height of thermals.................. 12006 ft MSL (6721 ft AGL)

Forecast maximum temperature................... 53.0 F/12.1 C
Time of trigger temperature.................... 1230 MST
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................. 7846 ft MSL (2560 ft AGL)
Thermal soaring outlook for Saturday 01/25..... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... Becoming good
Height of stable layer (12-18K ft MSL)......... 15844 ft MSL (10559 ft AGL)
Weak PVA/NVA (through 1700 MST)................ Neither
Potential height of wave....................... 18790 ft MSL (13505 ft AGL)
Wave soaring outlook for Saturday 01/25........ Poor

Remarks...

Sunrise/Sunset.................... 07:14:06 / 17:08:56 MST
Total possible sunshine........... 9 hr 54 min 50 sec (594 min 50 sec)
Altitude of sun at 12:11:31 MST... 30.98 degrees

Upper air data from rawinsonde observation taken on 01/24/2020 at 0500 MST

Freezing level.................. 5599 ft MSL (314 ft AGL)
Additional freezing level....... 8239 ft MSL (2954 ft AGL)
Convective condensation level... 17756 ft MSL (12471 ft AGL)
Lifted condensation level....... 14128 ft MSL (8843 ft AGL)
Lifted index.................... +8.4
K index......................... +5.3

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  -60.9 -77.6   325   42   22 -16.4  -9.0   98.0 208.5    49.4      M    M
 45000  -52.5 -62.5   310   51   26   1.5   0.8   87.5 189.4    46.4      M    M
 40000  -50.9 -59.6   320   53   27  -1.2  -0.6   65.7 150.2    35.4      M    M
 38000  -51.6 -60.9   315   66   34  -8.5  -4.7   56.0 132.8    29.8      M    M
 36000  -58.0 -72.4   315   80   41   7.5   4.1   38.0 100.4    18.2      M    M
 34000  -54.2 -65.6   320   89   46   8.7   4.8   35.3  95.5    16.8      M    M
 32000  -50.0 -58.0   325   79   41   5.6   3.1   32.9  91.3    15.5      M    M
 30000  -44.9 -48.8   330   70   36   8.3   4.6   32.0  89.5    15.2      M    M
 29000  -42.4 -44.3   330   66   34   8.4   4.6   31.3  88.3    14.8      M    M
 28000  -39.9 -39.8   325   62   32   8.4   4.6   30.7  87.2    14.6      M    M
 27000  -36.7 -34.1   325   57   30   8.6   4.7   30.1  86.2    14.4      M    M
 26000  -34.6 -30.3   320   53   28   6.5   3.6   29.1  84.5    13.8      M    M
 25000  -32.7 -26.9   320   50   26   7.1   3.9   27.9  82.3    13.0      M    M
 24000  -30.1 -22.2   320   45   23   8.5   4.7   27.6  81.6    12.8      M    M
 23000  -28.2 -18.8   320   38   19   5.8   3.2   26.3  79.3    11.9      M    M
 22000  -26.4 -15.5   325   35   18   7.2   4.0   24.9  76.8    10.9      M    M
 21000  -24.0 -11.2   335   32   16   8.5   4.7   24.4  75.9    10.6      M    M
 20000  -21.7  -7.1   335   31   16   7.3   4.0   23.7  74.6    10.1      M    M
 19500  -20.6  -5.1   330   32   16   7.3   4.0   23.2  73.8     9.7      M    M
 19000  -19.5  -3.1   330   33   17   7.3   4.0   22.8  73.0     9.4      M    M
 18500  -18.5  -1.3   325   34   17   7.8   4.3   22.4  72.3     9.1      M    M
 18000  -17.2   1.0   325   34   17   8.8   4.8   22.1  71.9     9.0      M    M
 17500  -15.9   3.4   325   33   17   8.8   4.8   22.0  71.6     8.9      M    M
 17000  -14.6   5.7   325   33   17   5.9   3.2   21.8  71.2     8.7      M    M
 16500  -14.0   6.8   325   32   17   4.3   2.4   20.8  69.5     7.9      M    M
 16000  -13.3   8.1   325   32   17   2.8   1.5   19.9  67.8     7.2      M    M
 15500  -13.2   8.2   325   32   16   0.9   0.5   18.4  65.2     5.9      M    M
 15000  -13.1   8.4   330   31   16   0.9   0.5   16.9  62.5     4.5      M    M
 14500  -12.8   9.0   330   31   16   3.8   2.1   15.7  60.3     3.4      M    M
 14000  -12.0  10.4   335   31   16   3.5   1.9   14.2  57.6     2.0      M    M
 13500  -11.5  11.3   345   31   16   3.5   1.9   13.2  55.7     1.1      M    M
 13000  -10.6  12.9   355   32   16   8.1   4.4   12.6  54.7     0.6      M    M
 12500   -9.5  14.9   350   32   16   7.7   4.2   12.3  54.1     0.2      M    M
 12000   -8.3  17.1   350   31   16   7.7   4.2   11.9  53.5    -0.1    538  2.7
 11500   -7.2  19.0   345   29   15   7.7   4.2   11.6  52.8    -0.4    489  2.5
 11000   -6.1  21.0   340   26   13   7.7   4.2   11.2  52.2    -0.7    440  2.2
 10500   -4.9  23.2   330   24   12   7.7   4.2   10.9  51.6    -1.1    391  2.0
 10250   -4.3  24.3   330   23   12   7.7   4.2   10.7  51.3    -1.2    367  1.9
 10000   -3.8  25.2   325   22   11   7.4   4.1   10.6  51.1    -1.4    343  1.7
  9750   -3.2  26.2   320   21   11   7.3   4.0   10.4  50.7    -1.6    319  1.6
  9500   -2.7  27.1   320   20   10   7.3   4.0   10.2  50.4    -1.7    295  1.5
  9250   -2.2  28.0   315   20   10   7.3   4.0   10.0  50.0    -1.9    272  1.4
  9000   -1.6  29.1   315   19   10   7.3   4.0    9.8  49.7    -2.1    248  1.3
  8750   -1.1  30.0   315   18    9   7.3   4.0    9.6  49.4    -2.3    224  1.1
  8500   -0.5  31.1   310   17    9   7.3   4.0    9.4  49.0    -2.5    201  1.0
  8250    0.0  32.0   310   16    8   7.3   4.0    9.3  48.7    -2.7    177  0.9
  8000    0.6  33.1   305   15    8   7.3   4.0    9.1  48.3    -2.9    154  0.8
  7750    1.1  34.0   305   14    7   7.3   4.0    8.9  48.0    -3.1    130  0.7
  7500    1.6  34.9   305   12    6   7.3   4.0    8.7  47.6    -3.3    106  0.5
  7250    2.2  36.0   300   11    6   7.2   4.0    8.5  47.3    -3.5     83  0.4
  7000    2.7  36.9   300   10    5   7.5   4.1    8.3  47.0    -3.7     59  0.3
  6750    3.3  37.9   300    9    5   6.5   3.6    8.1  46.6    -3.9     36  0.2
  6500    3.5  38.3   295    8    4  -1.5  -0.8    7.6  45.7    -4.4     21  0.1
  6250    3.3  37.9   295    7    4   0.8   0.4    6.6  44.0    -5.3     20  0.1
  6000    3.1  37.6   290    6    3 -19.4 -10.7    5.7  42.2    -6.3     19  0.1
  5750    0.7  33.3   285    4    2 -28.9 -15.8    2.5  36.5    -9.4     83  0.4
  5500   -0.3  31.5   260    1    0   1.0   0.6    0.9  33.5   -11.2    105  0.5

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

           01/24/2020 at 0800 MST          |       01/24/2020 at 1100 MST
                                           |
CAPE...     0.0    LI...       +5.5        | CAPE...     0.0    LI...       +5.8
CINH...    -0.2    K Index...  +8.5        | CINH...    -0.3    K Index...  +8.1
                                           |
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 -56.8 -70.2  310  16  8   2.0   1.1 | -56.5 -69.7  300  13  7   2.2   1.2
 45000 -53.8 -64.8  305  23 12   1.1   0.6 | -53.2 -63.8  300  19 10   1.2   0.7
 40000 -54.0 -65.2  305  29 15  -0.1  -0.1 | -53.8 -64.8  295  27 14  -0.4  -0.2
 38000 -54.1 -65.4  305  32 17  -0.2  -0.1 | -53.9 -65.0  295  30 15  -0.0  -0.0
 36000 -54.2 -65.6  305  36 19  -0.2  -0.1 | -53.9 -65.0  295  33 17  -0.0  -0.0
 34000 -53.6 -64.5  310  38 20   8.4   4.6 | -53.4 -64.1  295  34 18   7.9   4.3
 32000 -49.0 -56.2  310  33 17   7.7   4.2 | -49.1 -56.4  300  31 16   7.1   3.9
 30000 -44.4 -47.9  315  28 15   8.1   4.5 | -44.7 -48.5  300  27 14   8.7   4.7
 29000 -41.9 -43.4  315  28 14   8.1   4.5 | -42.2 -44.0  300  27 14   8.6   4.7
 28000 -39.5 -39.1  315  27 14   8.1   4.5 | -39.6 -39.3  300  26 13   8.6   4.7
 27000 -37.1 -34.8  315  26 14   8.1   4.4 | -37.0 -34.6  300  25 13   8.5   4.7
 26000 -34.7 -30.5  320  26 13   7.8   4.3 | -34.7 -30.5  300  24 12   7.6   4.2
 25000 -32.3 -26.1  320  25 13   7.8   4.3 | -32.4 -26.3  305  23 12   7.6   4.2
 24000 -30.0 -22.0  320  25 13   8.0   4.4 | -30.1 -22.2  305  21 11   7.7   4.2
 23000 -27.9 -18.2  320  23 12   6.8   3.7 | -27.9 -18.2  310  20 10   7.3   4.0
 22000 -25.8 -14.4  320  21 11   6.8   3.7 | -25.1 -13.2  310  19 10   7.3   4.0
 21000 -23.3  -9.9  320  19 10   6.4   3.5 | -23.0  -9.4  315  19 10   6.9   3.8
 20000 -21.4  -6.5  320  18  9   6.3   3.5 | -20.9  -5.6  315  18  9   6.8   3.7
 19500 -20.5  -4.9  320  17  9   6.4   3.5 | -19.9  -3.8  315  18  9   6.8   3.7
 19000 -19.5  -3.1  320  17  9   6.4   3.5 | -18.9  -2.0  315  18  9   6.8   3.7
 18500 -18.6  -1.5  320  16  8   6.2   3.4 | -17.9  -0.2  315  17  9   6.1   3.4
 18000 -17.7   0.1  320  16  8   6.1   3.3 | -17.1   1.2  320  17  9   5.7   3.2
 17500 -16.8   1.8  320  16  8   6.1   3.3 | -16.2   2.8  320  16  8   5.7   3.1
 17000 -15.9   3.4  320  15  8   5.7   3.1 | -15.5   4.1  320  16  8   4.9   2.7
 16500 -15.1   4.8  320  15  8   5.8   3.2 | -14.7   5.5  320  15  8   5.0   2.7
 16000 -14.3   6.3  325  14  7   5.1   2.8 | -14.0   6.8  320  14  7   4.8   2.6
 15500 -13.5   7.7  325  14  7   5.1   2.8 | -13.3   8.1  320  14  7   4.8   2.6
 15000 -12.8   9.0  325  13  7   5.4   3.0 | -12.6   9.3  320  13  7   5.3   2.9
 14500 -12.0  10.4  325  13  6   5.6   3.1 | -11.8  10.8  325  12  6   5.6   3.1
 14000 -11.1  12.0  325  12  6   5.8   3.2 | -11.0  12.2  325  11  6   5.8   3.2
 13500 -10.2  13.6  325  11  6   6.1   3.4 | -10.0  14.0  325  10  5   6.2   3.4
 13000  -9.3  15.3  325  10  5   6.2   3.4 |  -9.1  15.6  325   9  4   6.4   3.5
 12500  -8.4  16.9  330   9  5   6.5   3.6 |  -8.1  17.4  325   7  4   7.0   3.8
 12000  -7.4  18.7  330   8  4   6.7   3.7 |  -7.1  19.2  325   6  3   7.1   3.9
 11500  -6.3  20.7  330   8  4   7.2   4.0 |  -6.0  21.2  320   5  3   7.5   4.1
 11000  -5.3  22.5  330   7  4   7.2   4.0 |  -4.9  23.2  320   4  2   7.2   4.0
 10500  -4.2  24.4  325   6  3   7.2   4.0 |  -3.8  25.2  315   4  2   6.7   3.7
 10250  -3.6  25.5  325   6  3   7.8   4.3 |  -3.3  26.1  310   4  2   6.0   3.3
 10000  -3.1  26.4  325   6  3   5.6   3.1 |  -2.9  26.8  310   3  2   8.7   4.8
  9750  -2.7  27.1  320   6  3   5.8   3.2 |  -2.1  28.2  305   4  2   9.0   4.9
  9500  -2.2  28.0  315   6  3   8.1   4.4 |  -1.6  29.1  300   3  2   6.5   3.5
  9250  -1.6  29.1  310   6  3   7.5   4.1 |  -1.1  30.0  295   3  2   7.2   3.9
  9000  -1.1  30.0  305   6  3   5.6   3.1 |  -0.6  30.9  295   3  2   5.6   3.1
  8750  -0.7  30.7  305   6  3   5.7   3.1 |  -0.2  31.6  290   3  2   6.2   3.4
  8500  -0.2  31.6  305   6  3   7.7   4.2 |   0.4  32.7  290   3  2   7.7   4.2
  8250   0.4  32.7  305   6  3   6.4   3.5 |   0.9  33.6  290   3  2   7.2   3.9
  8000   0.8  33.4  305   6  3   4.6   2.5 |   1.5  34.7  290   4  2   7.0   3.8
  7750   1.1  34.0  300   6  3   3.6   2.0 |   2.0  35.6  290   4  2   6.1   3.4
  7500   1.3  34.3  300   7  3   3.7   2.0 |   2.4  36.3  290   4  2   6.3   3.5
  7250   1.6  34.9  300   7  4   2.9   1.6 |   2.8  37.0  290   4  2   4.3   2.3
  7000   1.8  35.2  300   6  3   2.1   1.1 |   3.0  37.4  290   4  2   1.5   0.8
  6750   1.9  35.4  300   5  3   2.6   1.4 |   3.2  37.8  285   3  2   3.8   2.1
  6500   2.1  35.8  295   5  2   1.4   0.8 |   3.6  38.5  275   3  1   5.5   3.0
  6250   2.1  35.8  290   4  2  -1.1  -0.6 |   4.0  39.2  265   2  1   5.5   3.0
  6000   2.0  35.6  275   3  1  -1.1  -0.6 |   4.4  39.9  245   2  1   5.2   2.8
  5750   1.9  35.4  255   2  1  -2.8  -1.5 |   4.8  40.6  210   1  1   6.8   3.8
  5500   1.2  34.2  230   2  1 -21.0 -11.5 |   5.5  41.9  205   1  1  13.9   7.6

           01/24/2020 at 1400 MST          |       01/24/2020 at 1700 MST
                                           |
CAPE...     0.0    LI...       +5.2        | CAPE...     0.0    LI...       +4.2
CINH...    -0.1    K Index...  +8.6        | CINH...     0.0    K Index...  +9.6
                                           |
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 -56.7 -70.1  290  12  6   2.4   1.3 | -56.4 -69.5  290  13  7   2.3   1.3
 45000 -53.1 -63.6  290  17  9   1.5   0.8 | -52.8 -63.0  285  17  9   2.0   1.1
 40000 -52.6 -62.7  285  26 13   0.3   0.2 | -50.5 -58.9  285  22 11   1.6   0.9
 38000 -52.9 -63.2  280  30 15  -1.5  -0.8 | -50.7 -59.3  280  26 13  -3.0  -1.7
 36000 -53.8 -64.8  280  33 17  -1.5  -0.8 | -52.5 -62.5  275  30 15  -3.0  -1.7
 34000 -54.1 -65.4  280  35 18   8.2   4.5 | -53.9 -65.0  270  34 17   5.4   2.9
 32000 -49.7 -57.5  280  34 17   7.2   4.0 | -50.3 -58.5  270  33 17   6.0   3.3
 30000 -45.3 -49.5  280  32 17   8.5   4.7 | -46.5 -51.7  265  32 17   8.5   4.7
 29000 -42.8 -45.0  280  31 16   8.5   4.6 | -44.0 -47.2  270  30 15   8.2   4.5
 28000 -40.2 -40.4  285  29 15   8.5   4.6 | -41.6 -42.9  270  28 14   8.2   4.5
 27000 -37.7 -35.9  285  28 14   8.5   4.6 | -39.1 -38.4  275  26 13   8.2   4.5
 26000 -35.3 -31.5  290  26 13   8.1   4.4 | -36.6 -33.9  280  24 12   8.3   4.6
 25000 -32.8 -27.0  290  24 12   8.1   4.4 | -34.1 -29.4  280  22 11   8.3   4.6
 24000 -30.4 -22.7  295  22 11   8.2   4.5 | -31.6 -24.9  285  20 10   8.4   4.6
 23000 -28.2 -18.8  295  20 10   7.3   4.0 | -29.3 -20.7  285  18  9   7.8   4.3
 22000 -26.0 -14.8  300  18  9   7.3   4.0 | -26.9 -16.4  285  17  9   7.8   4.3
 21000 -23.3  -9.9  305  16  8   6.9   3.8 | -24.1 -11.4  290  15  8   6.9   3.8
 20000 -21.3  -6.3  305  16  8   6.8   3.7 | -22.1  -7.8  290  14  7   6.6   3.6
 19500 -20.3  -4.5  305  16  8   6.8   3.7 | -21.1  -6.0  290  14  7   6.6   3.6
 19000 -19.3  -2.7  305  15  8   6.8   3.7 | -20.1  -4.2  295  13  7   6.6   3.6
 18500 -18.3  -0.9  310  15  8   6.6   3.6 | -19.1  -2.4  295  12  6   6.4   3.5
 18000 -17.3   0.9  310  15  8   6.4   3.5 | -18.2  -0.8  295  12  6   6.2   3.4
 17500 -16.3   2.7  310  14  7   6.4   3.5 | -17.3   0.9  295  11  6   6.2   3.4
 17000 -15.5   4.1  310  14  7   5.3   2.9 | -16.4   2.5  300  11  6   6.3   3.4
 16500 -14.7   5.5  305  13  7   5.4   3.0 | -15.4   4.3  300  11  6   6.3   3.4
 16000 -13.9   7.0  305  13  6   5.0   2.8 | -14.5   5.9  300  11  5   5.8   3.2
 15500 -13.2   8.2  305  12  6   5.0   2.8 | -13.7   7.3  300  10  5   5.7   3.1
 15000 -12.5   9.5  305  11  6   5.5   3.0 | -12.8   9.0  300  10  5   6.1   3.3
 14500 -11.6  11.1  305  10  5   5.8   3.2 | -11.9  10.6  300  10  5   6.4   3.5
 14000 -10.7  12.7  305   9  5   6.1   3.4 | -10.9  12.4  300  10  5   6.7   3.7
 13500  -9.8  14.4  305   8  4   6.7   3.7 |  -9.9  14.2  300  10  5   7.2   3.9
 13000  -8.8  16.2  300   8  4   6.8   3.7 |  -8.8  16.2  295   9  5   7.3   4.0
 12500  -7.7  18.1  300   7  4   7.5   4.1 |  -7.7  18.1  295   9  5   7.7   4.2
 12000  -6.6  20.1  295   7  3   7.4   4.1 |  -6.6  20.1  295   9  4   7.7   4.2
 11500  -5.5  22.1  295   6  3   7.5   4.1 |  -5.4  22.3  290   8  4   7.9   4.3
 11000  -4.4  24.1  290   6  3   7.3   4.0 |  -4.3  24.3  290   8  4   7.5   4.1
 10500  -3.4  25.9  290   5  3   6.4   3.5 |  -3.3  26.1  290   7  4   6.1   3.4
 10250  -2.9  26.8  290   5  3   6.4   3.5 |  -2.8  27.0  290   7  3   5.9   3.3
 10000  -2.3  27.9  290   5  3   9.6   5.3 |  -2.3  27.9  290   6  3   9.5   5.2
  9750  -1.5  29.3  290   5  2   9.6   5.3 |  -1.5  29.3  290   6  3   9.6   5.3
  9500  -1.0  30.2  290   4  2   6.9   3.8 |  -1.0  30.2  290   5  3   6.7   3.7
  9250  -0.4  31.3  285   4  2   8.1   4.4 |  -0.4  31.3  290   5  3   7.8   4.3
  9000   0.2  32.4  285   3  2   6.2   3.4 |   0.1  32.2  290   4  2   6.3   3.5
  8750   0.6  33.1  280   3  2   6.6   3.6 |   0.5  32.9  290   4  2   6.7   3.7
  8500   1.2  34.2  280   3  1   8.5   4.6 |   1.1  34.0  290   3  2   8.2   4.5
  8250   1.8  35.2  275   2  1   7.8   4.3 |   1.7  35.1  290   3  1   7.7   4.2
  8000   2.3  36.1  275   2  1   7.4   4.1 |   2.3  36.1  295   2  1   7.2   4.0
  7750   2.9  37.2  275   1  1   7.3   4.0 |   2.8  37.0  290   1  0   7.1   3.9
  7500   3.4  38.1  295   1  0   7.6   4.2 |   3.4  38.1  310   1  0   7.2   4.0
  7250   4.0  39.2  320   1  0   7.4   4.1 |   3.9  39.0  340   1  0   7.5   4.1
  7000   4.5  40.1  005   1  0   7.1   3.9 |   4.5  40.1  050   1  0   7.8   4.3
  6750   5.1  41.2  060   1  0   8.3   4.6 |   5.0  41.0  075   1  1   8.1   4.5
  6500   5.8  42.4  050   1  0   9.6   5.3 |   5.7  42.3  065   1  1   8.5   4.7
  6250   6.5  43.7  050   1  1   9.8   5.4 |   6.3  43.3  060   2  1   8.3   4.6
  6000   7.3  45.1  055   1  1  10.6   5.8 |   6.9  44.4  060   2  1   8.4   4.6
  5750   8.0  46.4  055   1  1   9.1   5.0 |   7.5  45.5  060   2  1   8.3   4.5
  5500   8.7  47.7  045   1  1  10.5   5.8 |   8.0  46.4  050   2  1   3.9   2.2
________________________________________________________________________________

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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