Soaring Guidance
Issued by NWS Pueblo, CO

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000
UXUS97 KPUB 301237
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0637 MDT Thursday, April 30, 2015

This forecast is for Thursday, April 30, 2015:

If the trigger temperature of 63.5 F/17.5 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1025 ft/min (5.2 m/s)
   Maximum height of thermals.................. 18577 ft MSL (11819 ft AGL)

Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 0900 MDT
Time of overdevelopment........................ 1500 MDT
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 15515 ft MSL (8757 ft AGL)
Thermal soaring outlook for Friday 05/01....... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:02:39 / 19:49:37 MDT
Total possible sunshine........... 13 hr 46 min 58 sec (826 min 58 sec)
Altitude of sun at 12:56:18 MDT... 65.89 degrees

Upper air data from numerical model forecast valid on 04/30/2015 at 0600 MDT

Freezing level.................. 13241 ft MSL (6483 ft AGL)
Convective condensation level... 18449 ft MSL (11691 ft AGL)
Lifted condensation level....... 18228 ft MSL (11471 ft AGL)
Lifted index.................... +0.3
K index......................... +12.5

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  -61.9 -79.4   270   16    8   2.7   1.5      M     M       M      M    M
 45000  -58.6 -73.5   245   19   10  -2.1  -1.1      M     M       M      M    M
 40000  -61.8 -79.2   260   23   12  -3.0  -1.6      M     M       M      M    M
 38000  -57.8 -72.0   260   21   11   8.3   4.5      M     M       M      M    M
 36000  -52.9 -63.2   260   19   10   8.3   4.5      M     M       M      M    M
 34000  -47.9 -54.2   265   18    9   8.2   4.5      M     M       M      M    M
 32000  -43.0 -45.4   270   17    9   8.2   4.5      M     M       M      M    M
 30000  -37.5 -35.5   275   15    8   8.0   4.4   31.9  89.4     7.5      M    M
 29000  -35.1 -31.2   275   14    7   8.0   4.4   31.2  88.2     7.0      M    M
 28000  -32.7 -26.9   280   12    6   8.0   4.4   30.7  87.2     6.7      M    M
 27000  -30.4 -22.7   280   12    6   7.5   4.1   29.9  85.8     6.1      M    M
 26000  -28.1 -18.6   285   11    6   7.5   4.1   29.0  84.2     5.5      M    M
 25000  -25.9 -14.6   290   11    6   7.5   4.1   28.2  82.8     4.9      M    M
 24000  -23.6 -10.5   295   11    6   7.6   4.2   27.4  81.4     4.3      M    M
 23000  -21.4  -6.5   310   12    6   7.6   4.2   26.6  79.9     3.6      M    M
 22000  -19.1  -2.4   320   13    7   7.6   4.2   25.9  78.6     3.1      M    M
 21000  -17.0   1.4   330   13    7   6.7   3.7   25.0  77.0     2.3      M    M
 20000  -15.0   5.0   335   12    6   6.7   3.7   23.9  75.0     1.3      M    M
 19500  -14.0   6.8   335   12    6   6.7   3.7   23.4  74.1     0.9      M    M
 19000  -13.0   8.6   340   11    6   6.7   3.7   22.9  73.2     0.5      M    M
 18500  -12.1  10.2   340   11    5   6.5   3.6   22.4  72.3    -0.0   1124  5.7
 18000  -11.1  12.0   340   10    5   6.5   3.6   21.8  71.3    -0.5   1080  5.5
 17500  -10.1  13.8   340   10    5   7.1   3.9   21.3  70.4    -1.0   1035  5.3
 17000   -9.0  15.8   330   11    6   7.4   4.0   20.9  69.7    -1.4    989  5.0
 16500   -8.0  17.6   320   12    6   7.3   4.0   20.5  69.0    -1.8    943  4.8
 16000   -7.0  19.4   320   13    6   6.7   3.7   20.1  68.1    -2.4    899  4.6
 15500   -6.1  21.0   320   13    7   6.6   3.6   19.6  67.2    -2.9    857  4.4
 15000   -5.0  23.0   325   13    7   8.6   4.7   19.2  66.6    -3.3    809  4.1
 14500   -3.1  26.4   335   14    7   8.5   4.7   18.9  66.0    -3.5    728  3.7
 14000   -1.8  28.8   340   13    7   8.7   4.8   18.7  65.7    -3.7    674  3.4
 13500   -0.4  31.3   350   13    7   8.7   4.8   18.5  65.4    -3.9    620  3.1
 13000    1.0  33.8   355   12    6   9.9   5.4   18.5  65.3    -3.9    563  2.9
 12500    2.4  36.3   355   12    6   8.1   4.4   18.5  65.3    -3.9    504  2.6
 12000    3.6  38.5   360   11    6   9.3   5.1   18.2  64.8    -4.3    454  2.3
 11750    4.3  39.7   360   11    6   9.0   4.9   18.2  64.7    -4.3    427  2.2
 11500    5.0  41.0   360   11    6   9.1   5.0   18.1  64.6    -4.4    399  2.0
 11250    5.6  42.1   360   11    5   9.1   5.0   18.1  64.5    -4.4    371  1.9
 11000    6.3  43.3   360   11    6   9.1   5.0   18.0  64.4    -4.5    343  1.7
 10750    7.0  44.6   355   11    6   8.9   4.9   17.9  64.3    -4.6    315  1.6
 10500    7.7  45.9   355   11    6   9.4   5.2   17.9  64.2    -4.6    288  1.5
 10250    8.4  47.1   355   11    6   7.6   4.2   17.8  64.1    -4.7    260  1.3
 10000    8.9  48.0   350   11    6   7.9   4.3   17.6  63.7    -4.9    237  1.2
  9750    9.6  49.3   350   12    6   9.9   5.4   17.6  63.7    -5.0    209  1.1
  9500   10.3  50.5   345   12    6   9.8   5.4   17.6  63.7    -5.0    180  0.9
  9250   11.0  51.8   345   13    6   8.8   4.8   17.6  63.6    -5.0    151  0.8
  9000   11.6  52.9   345   12    6   7.8   4.3   17.4  63.4    -5.2    126  0.6
  8750   12.2  54.0   340   12    6   8.8   4.8   17.3  63.2    -5.3    101  0.5
  8500   12.8  55.0   345   12    6   9.0   4.9   17.3  63.1    -5.4     74  0.4
  8250   13.4  56.1   345   11    6   4.6   2.5   17.1  62.8    -5.7     51  0.3
  8000   13.4  56.1   340   11    6  -2.0  -1.1   16.4  61.6    -6.4     43  0.2
  7750   13.4  56.1   335   10    5   9.6   5.2   15.8  60.4    -7.1     35  0.2
  7500   14.3  57.7   320   10    5   2.8   1.5   15.9  60.7    -7.0      2  0.0
  7250   13.0  55.4   310    9    5 -34.8 -19.1   14.2  57.6    -8.7     33  0.2
  7000    9.5  49.1   305    9    5 -50.1 -27.5   10.6  51.0   -12.4    129  0.7
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           04/30/2015 at 0900 MDT          |       04/30/2015 at 1200 MDT
                                           |
K index... +11.5  LI... +274.7             | K index... +15.1  LI... +272.5
CAPE... 0.0  CIN... M                      | CAPE... +12.7  CIN... -7.6
                                           |
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 -61.6 -78.9  250  19 10   2.0   1.1 | -62.6 -80.7  240  21 11   2.1   1.2
 45000 -59.2 -74.6  245  27 14  -2.1  -1.2 | -59.9 -75.8  245  29 15  -1.4  -0.8
 40000 -62.4 -80.3  260  21 11  -2.9  -1.6 | -62.1 -79.8  245  24 12  -2.1  -1.2
 38000 -58.4 -73.1  260  20 11   8.4   4.6 | -58.3 -72.9  245  24 13   8.0   4.4
 36000 -53.4 -64.1  255  20 11   8.4   4.6 | -53.5 -64.3  245  25 13   8.0   4.4
 34000 -48.4 -55.1  255  20 10   8.0   4.4 | -48.7 -55.7  250  24 12   8.0   4.4
 32000 -43.6 -46.5  270  20 10   8.0   4.4 | -43.8 -46.8  260  22 11   8.0   4.4
 30000 -38.1 -36.6  280  19 10   8.2   4.5 | -38.5 -37.3  275  20 10   7.8   4.3
 29000 -35.7 -32.3  285  19 10   8.2   4.5 | -36.2 -33.2  280  19 10   7.8   4.3
 28000 -33.2 -27.8  285  19 10   8.2   4.5 | -33.9 -29.0  290  18  9   7.8   4.3
 27000 -30.8 -23.4  290  19 10   7.8   4.3 | -31.5 -24.7  295  18  9   8.2   4.5
 26000 -28.5 -19.3  290  19 10   7.8   4.3 | -29.0 -20.2  295  19 10   8.2   4.5
 25000 -26.1 -15.0  290  18  9   7.8   4.3 | -26.6 -15.9  295  19 10   8.2   4.5
 24000 -23.8 -10.8  295  18  9   7.6   4.2 | -24.1 -11.4  295  19 10   8.3   4.6
 23000 -21.5  -6.7  300  16  8   7.7   4.2 | -21.6  -6.9  295  18  9   8.3   4.6
 22000 -19.3  -2.7  305  14  7   7.6   4.2 | -19.1  -2.4  290  17  9   8.3   4.5
 21000 -17.1   1.2  310  12  6   6.7   3.7 | -17.1   1.2  290  15  8   5.1   2.8
 20000 -15.1   4.8  315  10  5   6.7   3.7 | -15.7   3.7  300  13  7   5.1   2.8
 19500 -14.1   6.6  320   9  5   6.7   3.7 | -14.9   5.2  300  12  6   5.1   2.8
 19000 -13.1   8.4  325   8  4   6.7   3.7 | -14.2   6.4  305  11  5   5.6   3.1
 18500 -12.2  10.0  325   8  4   6.2   3.4 | -13.2   8.2  310  10  5   7.5   4.1
 18000 -11.3  11.7  325   8  4   6.3   3.4 | -12.1  10.2  315  10  5   7.3   4.0
 17500 -10.3  13.5  330   8  4   6.2   3.4 | -10.9  12.4  315  10  5   8.5   4.7
 17000  -9.4  15.1  335   8  4   6.2   3.4 |  -9.6  14.7  320   9  5   8.7   4.8
 16500  -8.6  16.5  345   9  5   6.7   3.7 |  -8.4  16.9  325   8  4   8.7   4.8
 16000  -7.5  18.5  350   9  5   7.7   4.3 |  -7.1  19.2  330   7  4   8.7   4.8
 15500  -6.4  20.5  355   9  5   7.7   4.2 |  -5.8  21.6  345   6  3   8.8   4.8
 15000  -5.2  22.6  360   9  5   8.5   4.7 |  -4.6  23.7  355   6  3   7.6   4.2
 14500  -3.3  26.1  005  10  5   8.7   4.7 |  -3.0  26.6  005   5  3   8.3   4.5
 14000  -2.0  28.4  010  10  5   9.2   5.1 |  -1.7  28.9  010   5  3   9.2   5.0
 13500  -0.6  30.9  015  10  5   9.2   5.1 |  -0.4  31.3  010   5  2   9.3   5.1
 13000   0.8  33.4  020   9  5  10.3   5.6 |   1.1  34.0  010   5  2  10.2   5.6
 12500   2.3  36.1  020   8  4   9.1   5.0 |   2.6  36.7  010   4  2   8.4   4.6
 12000   3.7  38.7  020   7  4   9.7   5.3 |   3.9  39.0  010   4  2  10.4   5.7
 11750   4.4  39.9  020   7  4   9.3   5.1 |   4.7  40.5  010   4  2   9.8   5.4
 11500   5.0  41.0  020   6  3   9.6   5.3 |   5.4  41.7  010   4  2  10.0   5.5
 11250   5.7  42.3  020   6  3   8.6   4.7 |   6.1  43.0  010   4  2   9.7   5.3
 11000   6.3  43.3  020   5  3   8.6   4.7 |   6.9  44.4  010   4  2   9.8   5.4
 10750   7.0  44.6  025   5  3   9.5   5.2 |   7.6  45.7  010   4  2   9.9   5.4
 10500   7.7  45.9  025   5  2   9.7   5.3 |   8.3  46.9  010   4  2  10.3   5.7
 10250   8.4  47.1  025   4  2   8.2   4.5 |   9.1  48.4  010   4  2   7.8   4.3
 10000   9.0  48.2  025   4  2   8.0   4.4 |   9.6  49.3  010   4  2   8.7   4.8
  9750   9.7  49.5  020   4  2   9.5   5.2 |  10.4  50.7  015   4  2  11.7   6.4
  9500  10.4  50.7  020   5  2   9.3   5.1 |  11.2  52.2  015   4  2  11.0   6.0
  9250  11.0  51.8  015   5  2   8.5   4.7 |  12.1  53.8  015   4  2  10.1   5.5
  9000  11.6  52.9  005   5  3   7.8   4.3 |  12.8  55.0  015   4  2   9.4   5.1
  8750  12.2  54.0  360   6  3   8.4   4.6 |  13.5  56.3  015   4  2  10.5   5.7
  8500  12.9  55.2  350   7  4   8.4   4.6 |  14.3  57.7  015   4  2  10.8   5.9
  8250  13.5  56.3  345   8  4   7.8   4.3 |  15.1  59.2  015   4  2  10.3   5.7
  8000  14.0  57.2  335   8  4   7.4   4.1 |  15.8  60.4  015   4  2  10.5   5.8
  7750  14.5  58.1  330   9  4   7.5   4.1 |  16.6  61.9  015   3  2   9.5   5.2
  7500  15.0  59.0  325   8  4   6.7   3.7 |  17.3  63.1  015   3  2  10.1   5.6
  7250  15.4  59.7  320   7  4   5.8   3.2 |  18.2  64.8  015   3  2  13.0   7.1
  7000  15.7  60.3  315   6  3   5.7   3.1 |  19.1  66.4  015   3  2  12.9   7.1
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/30/2015 at 1500 MDT          |       04/30/2015 at 1800 MDT
                                           |
K index... +22.7  LI... +271.4             | K index... +27.6  LI... +272.1
CAPE... +146.0  CIN... -7.4                | CAPE... +100.3  CIN... -1.3
                                           |
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  235  26 14   1.9   1.0 | -61.8 -79.2  245  29 15   1.8   1.0
 45000 -59.7 -75.5  245  32 17  -1.3  -0.7 | -59.5 -75.1  255  32 16  -2.2  -1.2
 40000 -61.7 -79.1  255  28 14  -2.0  -1.1 | -62.6 -80.7  260  31 16  -2.8  -1.5
 38000 -58.0 -72.4  260  29 15   7.6   4.2 | -58.9 -74.0  265  30 16   7.7   4.2
 36000 -53.4 -64.1  260  32 16   7.6   4.2 | -54.3 -65.7  275  30 16   7.7   4.2
 34000 -48.7 -55.7  260  32 16   8.2   4.5 | -49.4 -56.9  280  29 15   8.8   4.8
 32000 -43.7 -46.7  265  30 15   8.2   4.5 | -44.1 -47.4  290  28 15   8.8   4.8
 30000 -38.4 -37.1  270  27 14   7.6   4.2 | -38.8 -37.8  300  27 14   8.8   4.8
 29000 -36.1 -33.0  275  25 13   7.6   4.2 | -35.5 -31.9  300  26 13   8.8   4.8
 28000 -33.9 -29.0  280  24 12   7.6   4.2 | -32.9 -27.2  305  25 13   8.9   4.9
 27000 -31.5 -24.7  280  23 12   8.2   4.5 | -30.4 -22.7  310  22 12   8.1   4.5
 26000 -29.0 -20.2  285  22 11   8.2   4.5 | -28.0 -18.4  310  18  9   8.1   4.5
 25000 -26.6 -15.9  290  21 11   8.2   4.5 | -25.6 -14.1  310  14  7   8.1   4.5
 24000 -24.2 -11.6  295  21 11   7.5   4.1 | -23.3  -9.9  315  10  5   7.3   4.0
 23000 -22.0  -7.6  295  21 11   7.5   4.1 | -21.1  -6.0  320   4  2   7.3   4.0
 22000 -19.8  -3.6  300  21 11   7.5   4.1 | -19.0  -2.2  120   2  1   7.3   4.0
 21000 -17.7   0.1  300  20 10   6.6   3.6 | -16.9   1.6  125   5  2   6.9   3.8
 20000 -15.7   3.7  300  17  9   6.7   3.6 | -14.9   5.2  125   5  3   6.9   3.8
 19500 -14.8   5.4  300  16  8   6.7   3.7 | -13.9   7.0  125   6  3   6.9   3.8
 19000 -13.8   7.2  300  15  8   7.1   3.9 | -12.9   8.8  125   6  3   6.9   3.8
 18500 -12.6   9.3  305  12  6   8.3   4.5 | -11.8  10.8  120   6  3   6.9   3.8
 18000 -11.4  11.5  315   9  5   8.2   4.5 | -10.8  12.6  115   6  3   6.9   3.8
 17500 -10.2  13.6  335   7  3   8.4   4.6 |  -9.8  14.4  115   6  3   7.0   3.8
 17000  -9.0  15.8  355   5  2   8.5   4.6 |  -8.8  16.2  110   6  3   7.0   3.8
 16500  -7.7  18.1  030   4  2   8.5   4.7 |  -7.8  18.0  105   5  3   6.9   3.8
 16000  -6.5  20.3  055   5  2   8.7   4.8 |  -6.8  19.8  100   5  3   6.8   3.8
 15500  -5.2  22.6  070   6  3   8.7   4.8 |  -5.8  21.6  095   5  3   6.8   3.7
 15000  -4.0  24.8  070   6  3   8.6   4.7 |  -4.8  23.4  090   5  3   7.5   4.1
 14500  -2.1  28.2  075   6  3   8.9   4.9 |  -3.2  26.2  085   5  2   7.8   4.3
 14000  -0.7  30.7  075   6  3   9.5   5.2 |  -2.0  28.4  085   5  2   8.6   4.7
 13500   0.7  33.3  075   6  3   9.5   5.2 |  -0.7  30.7  085   5  2   8.7   4.8
 13000   2.2  36.0  080   6  3  10.2   5.6 |   0.8  33.4  085   5  2  11.4   6.2
 12500   3.7  38.7  080   6  3   8.4   4.6 |   2.5  36.5  080   5  2   9.9   5.4
 12000   5.0  41.0  080   5  3  10.1   5.5 |   4.0  39.2  085   5  2  10.4   5.7
 11750   5.7  42.3  080   5  3   9.6   5.3 |   4.7  40.5  085   5  2  10.1   5.5
 11500   6.4  43.5  085   5  3   9.6   5.3 |   5.5  41.9  085   5  2  10.2   5.6
 11250   7.1  44.8  085   5  3  10.0   5.5 |   6.3  43.3  085   5  2  10.1   5.5
 11000   7.9  46.2  085   5  3  10.2   5.6 |   7.0  44.6  085   5  2  10.2   5.6
 10750   8.6  47.5  085   5  3   9.7   5.3 |   7.8  46.0  085   5  2  10.0   5.5
 10500   9.4  48.9  090   5  3  10.4   5.7 |   8.5  47.3  085   5  2  10.7   5.9
 10250  10.1  50.2  090   5  3   8.2   4.5 |   9.3  48.7  085   5  2   8.2   4.5
 10000  10.7  51.3  090   5  2   8.8   4.8 |   9.8  49.6  085   5  2   8.6   4.7
  9750  11.5  52.7  090   5  2  11.4   6.2 |  10.6  51.1  085   5  2  11.4   6.3
  9500  12.3  54.1  090   5  2  10.8   5.9 |  11.4  52.5  085   5  2  10.8   5.9
  9250  13.1  55.6  090   5  2  10.0   5.5 |  12.2  54.0  085   5  2  10.2   5.6
  9000  13.8  56.8  095   5  2   9.3   5.1 |  13.0  55.4  085   4  2   9.6   5.2
  8750  14.5  58.1  095   5  2  10.3   5.6 |  13.7  56.7  085   4  2  10.3   5.7
  8500  15.3  59.5  095   4  2  10.5   5.8 |  14.5  58.1  085   4  2  10.5   5.8
  8250  16.1  61.0  095   4  2  10.3   5.6 |  15.3  59.5  085   4  2  10.2   5.6
  8000  16.9  62.4  100   4  2  10.6   5.8 |  16.0  60.8  085   4  2  10.2   5.6
  7750  17.6  63.7  100   4  2   9.3   5.1 |  16.8  62.2  085   4  2   9.7   5.3
  7500  18.3  64.9  100   4  2   9.6   5.3 |  17.4  63.3  085   4  2   8.2   4.5
  7250  19.1  66.4  100   4  2  13.0   7.1 |  18.0  64.4  085   3  2   6.7   3.7
  7000  20.1  68.2  100   4  2  13.8   7.6 |  18.4  65.1  085   3  2   6.0   3.3
  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) 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 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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