Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 241217
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0617 MDT Sunday, April 24, 2016

This forecast is for Sunday, April 24, 2016:

If the trigger temperature of 55.7 F/13.2 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1018 ft/min (5.2 m/s)
   Maximum height of thermals.................. 17043 ft MSL (11758 ft AGL)

Forecast maximum temperature................... 68.0 F/20.5 C
Time of trigger temperature.................... 0845 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 15965 ft MSL (10680 ft AGL)
Thermal soaring outlook for Monday 04/25....... Fair

Wave Soaring Index............................. Good
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 15865 ft MSL (10580 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 16358 ft MSL (11073 ft AGL)
Wave soaring outlook for Monday 04/25.......... Fair

Remarks...

Sunrise/Sunset.................... 06:08:26 / 19:46:20 MDT
Total possible sunshine........... 13 hr 37 min 55 sec (817 min 55 sec)
Altitude of sun at 12:57:33 MDT... 63.42 degrees

Upper air data from rawinsonde observation taken on 04/24/2016 at 0600 MDT

Freezing level.................. 9750 ft MSL (4465 ft AGL)
Convective condensation level... 14499 ft MSL (9214 ft AGL)
Lifted condensation level....... 16741 ft MSL (11456 ft AGL)
Lifted index.................... -1.0
K index......................... +13.8

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  -58.9 -74.0   225   34   18  -8.2  -4.5  100.1 212.1    46.0      M    M
 45000  -52.7 -62.9   260   29   15   6.1   3.4   84.7 184.5    39.9      M    M
 40000  -46.4 -51.5   275   29   15  -1.3  -0.7   71.6 160.9    34.0      M    M
 38000  -45.7 -50.3   260   43   22   6.6   3.6   63.9 147.0    29.6      M    M
 36000  -45.8 -50.4   240   59   31   4.1   2.3   55.2 131.3    24.3      M    M
 34000  -46.9 -52.4   225   67   34  -3.5  -1.9   45.4 113.7    18.0      M    M
 32000  -44.8 -48.6   215   73   37   5.0   2.7   40.1 104.2    14.7      M    M
 30000  -44.5 -48.1   205   81   42   0.7   0.4   31.6  89.0     8.7      M    M
 29000  -42.7 -44.9   210   72   37   8.7   4.8   30.1  86.1     7.6      M    M
 28000  -40.0 -40.0   215   63   32   9.0   4.9   29.7  85.5     7.5      M    M
 27000  -37.9 -36.2   225   56   29   6.2   3.4   28.7  83.7     6.8      M    M
 26000  -36.1 -33.0   230   56   29   5.2   2.8   27.3  81.1     5.7      M    M
 25000  -34.7 -30.5   230   56   29   4.9   2.7   25.5  77.9     4.4      M    M
 24000  -33.1 -27.6   235   56   29   8.4   4.6   23.8  74.8     3.0      M    M
 23000  -30.4 -22.7   235   54   28   8.2   4.5   23.4  74.1     2.7      M    M
 22000  -28.0 -18.4   240   50   26   8.2   4.5   22.7  72.9     2.2      M    M
 21000  -25.5 -13.9   240   47   24   8.2   4.5   22.2  72.0     1.8      M    M
 20000  -23.1  -9.6   245   43   22   7.9   4.3   21.8  71.3     1.5      M    M
 19500  -21.9  -7.4   245   42   21   7.8   4.3   21.4  70.6     1.2      M    M
 19000  -20.8  -5.4   245   40   21   7.7   4.2   21.1  70.0     0.9      M    M
 18500  -19.6  -3.3   250   40   21   7.6   4.2   20.8  69.4     0.6      M    M
 18000  -18.4  -1.1   255   40   21   9.1   5.0   20.5  68.9     0.4      M    M
 17500  -17.0   1.4   260   40   21   9.0   4.9   20.4  68.7     0.3      M    M
 17000  -15.7   3.7   270   42   21   5.2   2.8   20.2  68.4     0.1      M    M
 16500  -15.4   4.3   270   43   22   2.0   1.1   18.9  66.1    -1.0    997  5.1
 16000  -15.4   4.3   270   44   23  -0.5  -0.3   17.3  63.2    -2.5    982  5.0
 15500  -15.4   4.3   270   44   23   4.6   2.5   15.7  60.3    -4.0    968  4.9
 15000  -13.6   7.5   270   43   22   7.1   3.9   15.3  59.5    -4.5    893  4.5
 14500  -12.9   8.8   260   37   19   5.8   3.2   14.5  58.2    -5.2    856  4.3
 14000  -11.6  11.1   255   31   16  10.0   5.5   14.3  57.8    -5.5    803  4.1
 13500  -10.2  13.6   260   28   15   9.7   5.3   14.3  57.7    -5.5    745  3.8
 13000   -8.7  16.3   265   26   13   9.7   5.3   14.3  57.7    -5.6    686  3.5
 12500   -7.3  18.9   270   23   12   9.7   5.3   14.3  57.8    -5.6    628  3.2
 12000   -5.8  21.6   275   20   10   9.8   5.4   14.3  57.8    -5.6    569  2.9
 11500   -4.4  24.1   280   15    8   8.8   4.8   14.3  57.7    -5.7    512  2.6
 11000   -3.1  26.4   285   11    6   8.6   4.7   14.1  57.4    -5.9    459  2.3
 10500   -1.8  28.8   285   12    6   8.6   4.7   13.9  57.0    -6.1    406  2.1
 10250   -1.2  29.8   285   12    6   8.6   4.7   13.8  56.9    -6.2    379  1.9
 10000   -0.6  30.9   285   13    7   8.6   4.7   13.7  56.7    -6.3    353  1.8
  9750    0.1  32.2   285   14    7   8.8   4.8   13.7  56.6    -6.4    326  1.7
  9500    0.8  33.4   280   15    8   8.9   4.9   13.6  56.5    -6.5    299  1.5
  9250    1.4  34.5   275   17    9   8.9   4.9   13.5  56.4    -6.6    272  1.4
  9000    2.1  35.8   270   19   10   8.9   4.9   13.5  56.3    -6.6    244  1.2
  8750    2.7  36.9   270   19   10   8.9   4.9   13.4  56.2    -6.7    217  1.1
  8500    3.4  38.1   275   19   10   8.9   4.9   13.4  56.1    -6.8    190  1.0
  8250    4.1  39.4   275   20   10   8.9   4.9   13.3  56.0    -6.9    163  0.8
  8000    4.7  40.5   275   20   10   8.9   4.9   13.3  55.9    -7.0    135  0.7
  7750    5.4  41.7   275   21   11   8.9   4.9   13.2  55.7    -7.1    108  0.5
  7500    6.0  42.8   275   22   11   8.9   4.9   13.1  55.6    -7.1     81  0.4
  7250    6.7  44.1   275   22   11   8.9   4.9   13.1  55.5    -7.2     54  0.3
  7000    7.4  45.3   275   23   12   8.9   4.9   13.0  55.4    -7.3     27  0.1
  6750    8.0  46.4   275   22   11   8.9   4.9   12.9  55.2    -7.4      M    M
  6500    8.7  47.7   275   20   10   8.9   4.9   12.8  55.1    -7.5      M    M
  6250    9.4  48.9   270   19   10   9.2   5.0   12.8  55.0    -7.6      M    M
  6000   10.0  50.0   270   17    9   7.9   4.3   12.7  54.9    -7.7      M    M
  5750   10.7  51.3   275   11    6  12.7   6.9   12.6  54.7    -7.8      M    M
  5500   11.2  52.2   290    5    3  -9.8  -5.4   12.4  54.4    -8.0      M    M

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

           04/24/2016 at 0900 MDT          |       04/24/2016 at 1200 MDT
                                           |
K index... +7.1  LI... +3.5                | K index... +17.9  LI... +1.8
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.3
                                           |
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 -57.6 -71.7  245  30 16   3.8   2.1 | -57.4 -71.3  240  32 16   3.6   2.0
 45000 -51.7 -61.1  250  31 16   2.4   1.3 | -51.9 -61.4  245  32 16   0.9   0.5
 40000 -48.0 -54.4  270  37 19   2.5   1.4 | -50.5 -58.9  270  35 18   0.9   0.5
 38000 -46.5 -51.7  275  38 19   2.4   1.3 | -49.8 -57.6  280  38 20   1.5   0.8
 36000 -45.0 -49.0  280  36 19   2.4   1.3 | -49.0 -56.2  295  43 22   1.5   0.8
 34000 -43.6 -46.5  285  35 18   1.8   1.0 | -48.1 -54.6  305  50 26   1.6   0.9
 32000 -43.1 -45.6  290  33 17   0.7   0.4 | -47.1 -52.8  310  49 25   1.7   0.9
 30000 -42.6 -44.7  300  32 16   1.9   1.0 | -45.3 -49.5  315  49 25   9.4   5.2
 29000 -41.9 -43.4  305  33 17   2.2   1.2 | -42.7 -44.9  315  48 25   8.8   4.8
 28000 -41.3 -42.3  310  34 17   2.2   1.2 | -40.1 -40.2  310  47 24   8.8   4.8
 27000 -40.6 -41.1  315  35 18   1.9   1.0 | -37.5 -35.5  310  47 24   8.8   4.8
 26000 -38.9 -38.0  315  34 18   7.8   4.3 | -35.1 -31.2  305  45 23   7.9   4.3
 25000 -36.6 -33.9  310  32 16   7.8   4.3 | -32.7 -26.9  305  43 22   7.9   4.3
 24000 -34.3 -29.7  310  29 15   7.8   4.3 | -30.4 -22.7  300  41 21   7.9   4.3
 23000 -31.8 -25.2  305  28 14   8.5   4.7 | -28.1 -18.6  300  39 20   7.5   4.1
 22000 -29.2 -20.6  295  27 14   8.6   4.7 | -25.9 -14.6  295  36 19   7.5   4.1
 21000 -26.7 -16.1  285  26 14   8.6   4.7 | -23.6 -10.5  295  33 17   7.5   4.1
 20000 -24.1 -11.4  285  26 13   8.6   4.7 | -21.5  -6.7  295  31 16   7.1   3.9
 19500 -22.8  -9.0  285  26 13   8.6   4.7 | -20.5  -4.9  300  29 15   7.2   3.9
 19000 -21.5  -6.7  285  25 13   8.6   4.7 | -19.4  -2.9  300  28 14   7.2   3.9
 18500 -20.3  -4.5  285  25 13   8.7   4.7 | -18.3  -0.9  300  27 14   7.2   3.9
 18000 -19.0  -2.2  285  25 13   7.9   4.3 | -17.3   0.9  300  26 13   7.3   4.0
 17500 -17.8  -0.0  285  24 12   7.8   4.3 | -16.2   2.8  305  25 13   7.3   4.0
 17000 -16.7   1.9  285  22 12   7.6   4.2 | -15.1   4.8  305  25 13   7.4   4.1
 16500 -15.6   3.9  285  21 11   7.2   4.0 | -14.0   6.8  305  25 13   7.5   4.1
 16000 -14.0   6.8  290  17  9   7.6   4.1 | -12.3   9.9  305  25 13   7.9   4.3
 15500 -12.8   9.0  295  15  8   7.8   4.3 | -11.1  12.0  305  27 14   8.0   4.4
 15000 -11.7  10.9  300  13  7   7.9   4.3 | -10.0  14.0  310  29 15   8.2   4.5
 14500 -10.5  13.1  305  12  6   8.2   4.5 |  -8.7  16.3  310  30 16   8.6   4.7
 14000  -9.2  15.4  315  12  6   8.3   4.5 |  -7.4  18.7  305  32 17   8.6   4.7
 13500  -8.0  17.6  315  13  7   8.8   4.8 |  -6.1  21.0  305  33 17   8.4   4.6
 13000  -6.7  19.9  320  14  7   8.9   4.9 |  -4.9  23.2  305  34 18   8.5   4.6
 12500  -5.5  22.1  315  17  9   7.0   3.8 |  -3.7  25.3  305  36 18   7.6   4.1
 12000  -4.4  24.1  310  21 11   7.4   4.1 |  -2.6  27.3  305  38 19   7.9   4.3
 11500  -3.5  25.7  310  25 13   5.4   3.0 |  -1.6  29.1  300  39 20   5.0   2.8
 11000  -2.7  27.1  305  30 15   5.7   3.1 |  -0.8  30.6  300  40 21   5.4   2.9
 10500  -2.0  28.4  300  34 18   3.8   2.1 |  -0.1  31.8  295  40 20   4.7   2.6
 10250  -1.8  28.8  295  36 18   4.0   2.2 |   0.3  32.5  290  38 20   5.4   2.9
 10000  -1.5  29.3  295  37 19   3.5   1.9 |   0.7  33.3  290  37 19   6.6   3.6
  9750  -1.2  29.8  295  37 19   4.6   2.5 |   1.2  34.2  285  35 18   7.7   4.2
  9500  -0.9  30.4  290  35 18   5.6   3.1 |   1.8  35.2  285  32 17   8.1   4.5
  9250  -0.5  31.1  290  34 17   5.7   3.1 |   2.4  36.3  285  30 15   8.5   4.7
  9000  -0.1  31.8  285  32 16   4.4   2.4 |   3.1  37.6  280  28 14   6.7   3.7
  8750   0.2  32.4  285  30 15   5.8   3.2 |   3.5  38.3  280  26 13   6.8   3.7
  8500   0.8  33.4  285  28 14   8.2   4.5 |   4.1  39.4  280  23 12   9.0   5.0
  8250   1.3  34.3  280  25 13   7.4   4.0 |   4.7  40.5  275  21 11   7.8   4.3
  8000   1.9  35.4  280  23 12   8.4   4.6 |   5.4  41.7  275  18 10  10.5   5.8
  7750   2.5  36.5  275  20 11   8.0   4.4 |   6.2  43.2  270  17  9  10.3   5.7
  7500   3.1  37.6  270  18  9   6.9   3.8 |   6.8  44.2  270  15  8   7.7   4.2
  7250   3.6  38.5  270  16  8   7.2   4.0 |   7.4  45.3  265  14  7   8.2   4.5
  7000   4.1  39.4  265  14  7   7.5   4.1 |   8.0  46.4  260  12  6   9.1   5.0
  6750   4.7  40.5  260  13  7   8.5   4.7 |   8.8  47.8  260  12  6  10.2   5.6
  6500   5.4  41.7  255  12  6   8.9   4.9 |   9.5  49.1  260  12  6   9.9   5.4
  6250   6.0  42.8  245  11  5   8.9   4.9 |  10.3  50.5  260  11  6  10.1   5.5
  6000   6.7  44.1  240  10  5   8.8   4.9 |  11.0  51.8  260  11  5  10.8   5.9
  5750   7.3  45.1  240   9  5   9.8   5.4 |  11.8  53.2  260  10  5   9.6   5.2
  5500   8.2  46.8  235   8  4  14.3   7.8 |  12.6  54.7  255   9  5  13.4   7.3

           04/24/2016 at 1500 MDT          |       04/24/2016 at 1800 MDT
                                           |
K index... +16.0  LI... +1.7               | K index... +14.2  LI... +0.4
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.4
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -57.7 -71.9  230  28 14   3.2   1.8 | -57.7 -71.9  230  26 13   3.4   1.9
 45000 -52.9 -63.2  245  22 12  -0.7  -0.4 | -52.6 -62.7  230  18  9   0.7   0.4
 40000 -53.7 -64.7  290  49 25  -0.5  -0.3 | -57.6 -71.7  280  62 32  -3.2  -1.8
 38000 -53.4 -64.1  290  61 31   1.7   0.9 | -56.7 -70.1  285  73 38   5.2   2.9
 36000 -52.3 -62.1  295  70 36   1.7   1.0 | -53.5 -64.3  285  77 39   5.3   2.9
 34000 -51.0 -59.8  295  77 40   6.4   3.5 | -50.1 -58.2  290  78 40   7.7   4.2
 32000 -47.4 -53.3  285  59 30   6.0   3.3 | -45.5 -49.9  290  68 35   7.6   4.2
 30000 -43.1 -45.6  275  43 22   8.1   4.4 | -41.0 -41.8  285  59 30   7.5   4.1
 29000 -40.6 -41.1  275  41 21   8.2   4.5 | -38.2 -36.8  285  55 28   7.6   4.1
 28000 -38.2 -36.8  275  39 20   8.2   4.5 | -35.9 -32.6  285  52 27   7.6   4.1
 27000 -35.7 -32.3  275  37 19   8.3   4.6 | -33.6 -28.5  280  48 25   6.9   3.8
 26000 -33.2 -27.8  275  36 19   8.5   4.7 | -31.7 -25.1  280  44 22   6.4   3.5
 25000 -30.6 -23.1  280  36 19   8.5   4.7 | -29.8 -21.6  275  39 20   6.4   3.5
 24000 -28.1 -18.6  280  36 18   8.5   4.7 | -27.9 -18.2  270  35 18   6.5   3.5
 23000 -25.7 -14.3  280  35 18   7.7   4.2 | -25.9 -14.6  270  32 16   6.9   3.8
 22000 -23.4 -10.1  285  33 17   7.8   4.3 | -23.8 -10.8  265  29 15   6.9   3.8
 21000 -21.1  -6.0  290  32 17   7.5   4.1 | -21.8  -7.2  265  27 14   7.6   4.1
 20000 -19.1  -2.4  295  32 16   6.9   3.8 | -19.4  -2.9  265  25 13   8.1   4.4
 19500 -18.0  -0.4  295  31 16   7.0   3.8 | -18.1  -0.6  265  25 13   8.1   4.5
 19000 -17.0   1.4  300  31 16   7.0   3.8 | -16.9   1.6  265  24 12   8.1   4.5
 18500 -16.0   3.2  300  31 16   7.0   3.8 | -15.7   3.7  265  23 12   8.1   4.5
 18000 -15.1   4.8  305  31 16   5.9   3.2 | -14.5   5.9  270  24 12   8.1   4.4
 17500 -14.2   6.4  305  31 16   6.0   3.3 | -13.3   8.1  280  24 13   8.2   4.5
 17000 -13.3   8.1  305  32 16   6.6   3.6 | -12.2  10.0  285  26 13   7.0   3.8
 16500 -12.3   9.9  310  33 17   6.8   3.7 | -11.2  11.8  285  27 14   6.8   3.7
 16000 -10.8  12.6  310  34 18   6.6   3.6 | -10.2  13.6  285  28 14   6.4   3.5
 15500  -9.8  14.4  305  36 19   6.6   3.6 |  -9.3  15.3  290  30 15   5.7   3.1
 15000  -8.8  16.2  305  38 20   6.3   3.5 |  -8.1  17.4  295  33 17   6.2   3.4
 14500  -8.0  17.6  305  39 20   6.0   3.3 |  -7.2  19.0  295  34 18   6.5   3.6
 14000  -7.1  19.2  300  40 21   6.1   3.3 |  -6.2  20.8  295  36 18   7.2   3.9
 13500  -6.2  20.8  300  41 21   6.3   3.4 |  -5.1  22.8  295  36 18   8.1   4.5
 13000  -5.2  22.6  295  42 22   6.4   3.5 |  -3.9  25.0  295  36 18   8.1   4.4
 12500  -4.2  24.4  295  40 21   7.3   4.0 |  -2.7  27.1  295  34 18   7.8   4.3
 12000  -3.2  26.2  290  37 19   7.3   4.0 |  -1.6  29.1  295  33 17   7.9   4.3
 11500  -2.0  28.4  290  34 18   8.9   4.9 |  -0.5  31.1  290  30 15   8.0   4.4
 11000  -0.7  30.7  285  31 16   8.7   4.8 |   0.7  33.3  290  27 14   8.1   4.5
 10500   0.6  33.1  285  28 14   9.0   4.9 |   1.9  35.4  285  25 13   8.7   4.7
 10250   1.2  34.2  285  26 13   9.2   5.0 |   2.6  36.7  285  24 12   9.5   5.2
 10000   1.9  35.4  285  25 13   9.6   5.3 |   3.3  37.9  285  23 12  10.5   5.8
  9750   2.7  36.9  285  23 12  10.0   5.5 |   4.1  39.4  285  22 11   9.9   5.4
  9500   3.4  38.1  280  22 12  10.1   5.6 |   4.8  40.6  285  21 11   9.6   5.3
  9250   4.2  39.6  280  21 11  10.2   5.6 |   5.5  41.9  285  20 10   9.6   5.3
  9000   4.9  40.8  280  20 10   9.6   5.3 |   6.2  43.2  280  19 10   8.9   4.9
  8750   5.6  42.1  280  20 10   9.4   5.1 |   6.9  44.4  280  18  9   8.7   4.7
  8500   6.3  43.3  280  19 10   9.8   5.4 |   7.5  45.5  280  17  9   9.2   5.0
  8250   7.0  44.6  280  19 10   9.1   5.0 |   8.2  46.8  280  16  8   8.4   4.6
  8000   7.7  45.9  280  18  9  11.2   6.1 |   8.8  47.8  280  15  8  11.0   6.0
  7750   8.6  47.5  280  18  9  10.9   6.0 |   9.7  49.5  280  14  7  10.8   5.9
  7500   9.3  48.7  280  17  9   8.6   4.7 |  10.4  50.7  275  13  7   8.1   4.5
  7250  10.0  50.0  280  17  9   9.3   5.1 |  11.0  51.8  275  13  7   8.9   4.9
  7000  10.7  51.3  280  17  9   9.8   5.4 |  11.7  53.1  275  13  6   9.6   5.3
  6750  11.4  52.5  280  16  8  10.1   5.5 |  12.4  54.3  275  12  6  10.0   5.5
  6500  12.2  54.0  280  16  8   9.7   5.3 |  13.1  55.6  275  12  6   9.6   5.3
  6250  12.9  55.2  280  16  8  10.0   5.5 |  13.9  57.0  275  11  6   9.7   5.3
  6000  13.7  56.7  280  15  8  10.8   5.9 |  14.6  58.3  275  11  6   9.8   5.4
  5750  14.5  58.1  280  14  7  10.2   5.6 |  15.3  59.5  275  10  5   9.6   5.3
  5500  15.3  59.5  280  13  7  14.3   7.8 |  16.0  60.8  275   9  5  10.4   5.7
________________________________________________________________________________

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.

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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