Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 241232
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0632 MDT Thursday, April 24, 2014

This forecast is for Thursday, April 24, 2014:

If the trigger temperature of 45.6 F/7.6 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 633 ft/min (3.2 m/s)
   Maximum height of thermals.................. 15025 ft MSL (9740 ft AGL)

Forecast maximum temperature................... 67.0 F/19.9 C
Time of trigger temperature.................... 0730 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 13544 ft MSL (8258 ft AGL)
Thermal soaring outlook for Friday 04/25....... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... Little change
Height of stable layer (12-18K ft MSL)......... 14374 ft MSL (9089 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 14865 ft MSL (9580 ft AGL)
Wave soaring outlook for Friday 04/25.......... Fair

Remarks...

Sunrise/Sunset.................... 06:09:08 / 19:45:49 MDT
Total possible sunshine........... 13 hr 36 min 41 sec (816 min 41 sec)
Altitude of sun at 12:57:38 MDT... 63.25 degrees

Upper air data from rawinsonde observation taken on 04/24/2014 at 0600 MDT

Freezing level.................. 7656 ft MSL (2371 ft AGL)
Convective condensation level... 18389 ft MSL (13104 ft AGL)
Lifted condensation level....... 17900 ft MSL (12615 ft AGL)
Lifted index.................... +1.4
K index......................... -17.2

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  -61.3 -78.3   245   23   12   3.1   1.7   98.5 209.2    45.1      M    M
 45000  -59.2 -74.6   260   39   20  -1.2  -0.7   77.4 171.4    35.4      M    M
 40000  -52.7 -62.9   275   31   16   7.9   4.3   63.5 146.3    28.9      M    M
 38000  -50.6 -59.1   285   41   21   5.5   3.0   57.9 136.2    25.9      M    M
 36000  -56.0 -68.8   305   55   28   8.4   4.6   41.5 106.6    15.2      M    M
 34000  -54.7 -66.5   315   72   37  -0.9  -0.5   35.0  95.0    11.0      M    M
 32000  -51.5 -60.7   315   67   34   6.3   3.5   31.3  88.3     8.6      M    M
 30000  -48.7 -55.7   315   57   30   8.6   4.7   27.3  81.1     5.8      M    M
 29000  -46.1 -51.0   315   55   28   8.6   4.7   26.7  80.0     5.5      M    M
 28000  -42.9 -45.2   315   51   26   8.6   4.7   26.1  79.0     5.1      M    M
 27000  -40.3 -40.5   320   47   24   8.8   4.8   25.8  78.5     4.9      M    M
 26000  -37.6 -35.7   320   44   23   8.9   4.9   25.5  77.8     4.7      M    M
 25000  -35.0 -31.0   320   41   21   8.9   4.9   25.2  77.3     4.6      M    M
 24000  -32.3 -26.1   320   42   22   9.2   5.0   24.9  76.8     4.4      M    M
 23000  -29.6 -21.3   320   42   22   8.8   4.8   24.5  76.0     4.1      M    M
 22000  -27.0 -16.6   320   42   21   8.8   4.8   24.1  75.3     3.8      M    M
 21000  -24.3 -11.7   320   41   21   8.9   4.9   23.8  74.8     3.6      M    M
 20000  -22.0  -7.6   320   41   21   4.6   2.5   23.3  73.9     3.2      M    M
 19500  -21.2  -6.2   320   36   19   4.6   2.6   22.4  72.3     2.5      M    M
 19000  -20.3  -4.5   320   31   16   9.1   5.0   21.8  71.3     2.0      M    M
 18500  -18.8  -1.8   325   33   17   9.3   5.1   21.8  71.2     2.0      M    M
 18000  -17.6   0.3   325   33   17   7.8   4.3   21.5  70.8     1.7      M    M
 17500  -16.4   2.5   325   34   17   7.9   4.3   21.2  70.2     1.5      M    M
 17000  -15.2   4.6   320   34   18   7.9   4.3   20.9  69.6     1.2      M    M
 16500  -14.1   6.6   320   34   18   7.7   4.2   20.6  69.1     0.9      M    M
 16000  -12.9   8.8   320   35   18   7.7   4.2   20.3  68.5     0.7      M    M
 15500  -11.7  10.9   320   37   19   7.7   4.2   19.9  67.8     0.4      M    M
 15000  -10.6  12.9   320   39   20   6.7   3.7   19.6  67.3     0.1      M    M
 14500   -9.7  14.5   315   40   21  -1.1  -0.6   18.9  66.0    -0.5    600  3.0
 14000   -9.4  15.1   315   41   21   5.6   3.1   16.9  62.4    -2.4    567  2.9
 13500   -9.0  15.8   320   35   18  -0.8  -0.4   15.7  60.3    -3.4    540  2.7
 13000   -9.1  15.6   320   29   15  -0.7  -0.4   14.0  57.3    -5.1    529  2.7
 12500   -9.2  15.4   315   25   13  -1.1  -0.6   12.3  54.2    -6.7    519  2.6
 12000   -9.0  15.8   310   21   11   6.6   3.6   11.1  51.9    -8.0    497  2.5
 11500   -7.8  18.0   305   18    9   7.2   4.0   10.8  51.4    -8.3    447  2.3
 11000   -7.1  19.2   300   16    8   3.9   2.2   10.0  50.1    -9.0    410  2.1
 10500   -6.5  20.3   285   21   11   4.2   2.3    9.1  48.5   -10.0    378  1.9
 10250   -6.2  20.8   280   24   13   4.0   2.2    8.7  47.7   -10.4    362  1.8
 10000   -5.9  21.4   280   27   14   4.9   2.7    8.3  46.9   -10.9    346  1.8
  9750   -5.4  22.3   280   24   12   7.8   4.3    8.0  46.4   -11.2    325  1.6
  9500   -4.8  23.4   275   21   11   9.1   5.0    7.9  46.3   -11.3    298  1.5
  9250   -4.1  24.6   275   18    9   8.8   4.8    7.9  46.1   -11.4    271  1.4
  9000   -3.5  25.7   270   15    8   8.7   4.8    7.8  46.0   -11.5    244  1.2
  8750   -2.8  27.0   275   12    6   8.6   4.7    7.7  45.9   -11.6    217  1.1
  8500   -2.2  28.0   280   10    5   8.7   4.8    7.6  45.7   -11.7    190  1.0
  8250   -1.5  29.3   290    8    4   8.7   4.7    7.5  45.6   -11.8    163  0.8
  8000   -0.9  30.4   305    7    4   8.7   4.8    7.5  45.5   -11.9    136  0.7
  7750   -0.2  31.6   325    7    4   8.6   4.7    7.4  45.3   -12.0    109  0.6
  7500    0.4  32.7   340    9    4   9.0   5.0    7.3  45.1   -12.2     82  0.4
  7250    1.1  34.0   350   10    5   7.3   4.0    7.2  45.0   -12.3     55  0.3
  7000    1.4  34.5   360   12    6   0.9   0.5    6.8  44.3   -12.7     38  0.2
  6750    1.4  34.5   005   11    6   2.4   1.3    6.1  42.9   -13.5     31  0.2
  6500    1.9  35.4   005    9    5   8.2   4.5    5.8  42.4   -13.8     10  0.1
  6250    2.5  36.5   010    8    4   8.6   4.7    5.7  42.3   -13.9      M    M
  6000    3.1  37.6   020    7    4   8.3   4.5    5.6  42.1   -14.0      M    M
  5750    3.7  38.7   020    5    2   9.1   5.0    5.5  41.9   -14.2      M    M
  5500    4.3  39.7   020    2    1   5.9   3.3    5.4  41.8   -14.3      M    M

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

           04/24/2014 at 0900 MDT          |       04/24/2014 at 1200 MDT
                                           |
K index... -10.5  LI... +9.0               | K index... -8.8  LI... +7.4
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.9
                                           |
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 -56.9 -70.4  265  25 13  -0.5  -0.3 | -57.5 -71.5  270  26 14  -0.4  -0.2
 45000 -57.6 -71.7  275  30 16  -0.6  -0.3 | -58.0 -72.4  285  34 17  -0.3  -0.2
 40000 -56.3 -69.3  295  51 26   0.8   0.5 | -59.9 -75.8  290  65 33  -1.2  -0.7
 38000 -56.0 -68.8  300  59 30   0.3   0.2 | -59.2 -74.6  290  70 36   3.7   2.0
 36000 -55.8 -68.4  310  66 34   0.3   0.2 | -57.0 -70.6  295  67 34   3.7   2.0
 34000 -55.2 -67.4  315  73 37   7.3   4.0 | -54.4 -65.9  295  64 33   8.3   4.5
 32000 -50.7 -59.3  315  64 33   7.5   4.1 | -49.8 -57.6  295  59 30   7.8   4.3
 30000 -46.1 -51.0  310  56 29   8.2   4.5 | -45.1 -49.2  295  55 28   7.4   4.1
 29000 -43.7 -46.7  310  53 27   8.1   4.4 | -42.9 -45.2  295  53 27   7.5   4.1
 28000 -41.3 -42.3  310  51 26   8.1   4.4 | -40.6 -41.1  295  51 26   7.5   4.1
 27000 -38.3 -36.9  315  47 24   8.1   4.5 | -37.8 -36.0  295  49 25   7.9   4.3
 26000 -35.8 -32.4  310  45 23   8.2   4.5 | -35.4 -31.7  300  46 24   8.1   4.4
 25000 -33.4 -28.1  310  43 22   8.2   4.5 | -33.0 -27.4  300  44 23   8.1   4.4
 24000 -31.0 -23.8  310  41 21   8.1   4.4 | -30.6 -23.1  300  42 21   7.8   4.3
 23000 -28.6 -19.5  310  39 20   7.8   4.3 | -28.3 -18.9  295  39 20   7.4   4.1
 22000 -26.3 -15.3  310  36 19   7.8   4.3 | -26.1 -15.0  295  36 19   7.4   4.1
 21000 -23.9 -11.0  315  34 17   8.0   4.4 | -23.9 -11.0  295  34 17   8.0   4.4
 20000 -21.5  -6.7  310  31 16   8.1   4.4 | -21.4  -6.5  290  33 17   8.2   4.5
 19500 -20.3  -4.5  310  30 15   8.1   4.4 | -20.2  -4.4  290  33 17   8.2   4.5
 19000 -19.1  -2.4  310  28 14   8.1   4.4 | -19.0  -2.2  290  33 17   8.2   4.5
 18500 -17.9  -0.2  310  27 14   7.8   4.3 | -17.8  -0.0  290  33 17   7.9   4.4
 18000 -16.8   1.8  315  27 14   7.3   4.0 | -16.6   2.1  290  32 16   7.8   4.3
 17500 -15.7   3.7  315  28 15   7.5   4.1 | -15.5   4.1  295  31 16   7.8   4.3
 17000 -14.7   5.5  320  29 15   6.0   3.3 | -14.4   6.1  295  31 16   6.9   3.8
 16500 -13.8   7.2  320  29 15   6.1   3.3 | -13.3   8.1  295  30 16   7.0   3.9
 16000 -12.9   8.8  320  28 15   5.6   3.1 | -12.3   9.9  300  30 15   6.2   3.4
 15500 -12.1  10.2  325  29 15   5.3   2.9 | -11.4  11.5  300  29 15   6.1   3.3
 15000 -11.3  11.7  325  29 15   5.0   2.7 | -10.5  13.1  300  27 14   5.7   3.1
 14500 -10.7  12.7  330  29 15   4.1   2.2 |  -9.7  14.5  300  26 13   5.4   2.9
 14000  -9.8  14.4  330  29 15   3.7   2.0 |  -8.5  16.7  300  24 12   5.0   2.7
 13500  -9.3  15.3  335  28 14   3.5   1.9 |  -7.8  18.0  300  22 11   4.9   2.7
 13000  -8.8  16.2  335  27 14   4.1   2.3 |  -7.0  19.4  300  21 11   5.6   3.1
 12500  -8.1  17.4  335  26 13   4.6   2.5 |  -6.2  20.8  300  20 10   5.9   3.2
 12000  -7.4  18.7  335  25 13   4.7   2.6 |  -5.3  22.5  300  19 10   6.2   3.4
 11500  -6.7  19.9  335  24 12   4.7   2.6 |  -4.3  24.3  300  19 10   6.4   3.5
 11000  -6.0  21.2  340  24 12   5.8   3.2 |  -3.4  25.9  300  18  9   6.2   3.4
 10500  -5.0  23.0  340  23 12   7.0   3.8 |  -2.5  27.5  295  19 10   6.6   3.6
 10250  -4.5  23.9  340  22 11   4.5   2.5 |  -2.1  28.2  295  19 10   3.7   2.0
 10000  -4.3  24.3  340  22 11   4.2   2.3 |  -1.9  28.6  295  19 10   3.6   2.0
  9750  -3.8  25.2  340  21 11   7.0   3.8 |  -1.5  29.3  295  18  9   6.5   3.5
  9500  -3.3  26.1  335  20 10   7.1   3.9 |  -1.0  30.2  290  17  9   6.0   3.3
  9250  -2.8  27.0  335  19 10   6.2   3.4 |  -0.6  30.9  290  15  8   5.2   2.8
  9000  -2.4  27.7  335  18  9   5.6   3.1 |  -0.3  31.5  290  14  7   5.1   2.8
  8750  -1.9  28.6  330  17  9   7.4   4.1 |   0.2  32.4  285  12  6   6.9   3.8
  8500  -1.3  29.7  325  16  8   8.9   4.9 |   0.7  33.3  285  10  5   6.9   3.8
  8250  -0.7  30.7  315  16  8   6.6   3.6 |   1.2  34.2  280   8  4   8.5   4.7
  8000  -0.3  31.5  315  14  7   4.7   2.6 |   1.9  35.4  275   7  4  10.1   5.6
  7750   0.1  32.2  310  13  7   5.7   3.1 |   2.6  36.7  275   7  4   9.6   5.3
  7500   0.5  32.9  310  12  6   6.4   3.5 |   3.3  37.9  275   7  3   9.8   5.4
  7250   1.0  33.8  305  11  6   7.4   4.1 |   4.1  39.4  275   6  3  10.1   5.5
  7000   1.6  34.9  300  11  5   7.9   4.3 |   4.8  40.6  275   6  3  10.3   5.6
  6750   2.2  36.0  295  10  5   7.8   4.3 |   5.6  42.1  275   6  3   9.7   5.3
  6500   2.8  37.0  290  10  5   8.9   4.9 |   6.3  43.3  275   6  3  10.5   5.7
  6250   3.5  38.3  285   9  5  10.1   5.5 |   7.2  45.0  275   6  3  11.9   6.5
  6000   4.1  39.4  280   8  4   9.0   5.0 |   8.0  46.4  275   6  3  10.2   5.6
  5750   4.8  40.6  275   7  4  11.4   6.2 |   8.8  47.8  275   5  3  13.5   7.4
  5500   5.9  42.6  275   7  4  18.8  10.3 |  10.2  50.4  275   5  3  24.7  13.5

           04/24/2014 at 1500 MDT          |       04/24/2014 at 1800 MDT
                                           |
K index... +3.0  LI... +4.4                | K index... +13.4  LI... +1.7
CAPE... 0.0  CIN... -0.8                   | CAPE... 0.0  CIN... M
                                           |
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  270  30 16   0.6   0.3 | -57.7 -71.9  275  35 18   0.3   0.2
 45000 -56.2 -69.2  285  38 20   0.8   0.4 | -57.2 -71.0  285  48 25   0.4   0.2
 40000 -59.5 -75.1  285  65 34  -2.2  -1.2 | -59.5 -75.1  285  64 33  -1.5  -0.8
 38000 -59.1 -74.4  285  70 36   3.7   2.0 | -58.8 -73.8  290  67 34   3.8   2.1
 36000 -56.9 -70.4  285  69 35   3.7   2.0 | -56.5 -69.7  290  67 34   3.8   2.1
 34000 -54.3 -65.7  280  67 34   8.0   4.4 | -53.9 -65.0  290  66 34   7.4   4.1
 32000 -49.7 -57.5  280  61 31   7.7   4.2 | -49.6 -57.3  290  62 32   7.1   3.9
 30000 -45.1 -49.2  280  55 28   8.0   4.4 | -45.3 -49.5  285  58 30   8.1   4.4
 29000 -42.7 -44.9  280  52 27   8.0   4.4 | -42.9 -45.2  285  56 29   8.0   4.4
 28000 -39.7 -39.5  280  49 25   8.0   4.4 | -39.9 -39.8  285  54 28   8.0   4.4
 27000 -37.3 -35.1  280  47 24   7.9   4.3 | -37.5 -35.5  285  53 27   8.2   4.5
 26000 -34.9 -30.8  280  45 23   7.9   4.3 | -35.0 -31.0  285  50 26   8.2   4.5
 25000 -32.6 -26.7  280  43 22   7.9   4.3 | -32.6 -26.7  285  48 25   8.3   4.5
 24000 -30.3 -22.5  280  41 21   7.6   4.2 | -30.1 -22.2  285  46 24   7.7   4.2
 23000 -28.1 -18.6  285  39 20   7.2   3.9 | -28.0 -18.4  285  43 22   7.0   3.9
 22000 -26.0 -14.8  285  37 19   7.2   3.9 | -25.9 -14.6  285  41 21   7.0   3.9
 21000 -23.8 -10.8  285  35 18   7.7   4.2 | -23.8 -10.8  285  39 20   7.1   3.9
 20000 -21.5  -6.7  285  34 18   7.7   4.3 | -21.7  -7.1  285  39 20   7.1   3.9
 19500 -20.4  -4.7  285  34 18   7.8   4.3 | -20.7  -5.3  285  38 20   7.1   3.9
 19000 -19.2  -2.6  285  34 17   7.8   4.3 | -19.6  -3.3  280  38 20   7.1   3.9
 18500 -18.1  -0.6  285  34 17   7.6   4.2 | -18.6  -1.5  280  38 20   7.5   4.1
 18000 -16.9   1.6  285  33 17   7.6   4.1 | -17.4   0.7  280  38 20   7.6   4.2
 17500 -15.8   3.6  285  32 16   7.6   4.2 | -16.3   2.7  280  38 19   7.7   4.2
 17000 -14.6   5.7  285  31 16   8.3   4.5 | -15.1   4.8  280  37 19   8.5   4.7
 16500 -13.4   7.9  290  29 15   8.3   4.5 | -13.8   7.2  280  35 18   8.5   4.7
 16000 -12.2  10.0  290  28 14   7.4   4.0 | -12.6   9.3  280  34 17   7.8   4.3
 15500 -11.1  12.0  290  27 14   7.3   4.0 | -11.4  11.5  280  33 17   7.8   4.3
 15000 -10.0  14.0  290  27 14   7.0   3.8 | -10.3  13.5  280  31 16   8.3   4.5
 14500  -9.0  15.8  290  26 14   6.7   3.7 |  -9.0  15.8  280  31 16   8.6   4.7
 14000  -7.5  18.5  290  26 14   6.9   3.8 |  -7.1  19.2  280  29 15   7.7   4.2
 13500  -6.5  20.3  285  27 14   6.9   3.8 |  -6.0  21.2  280  29 15   7.7   4.2
 13000  -5.4  22.3  285  28 14   6.8   3.7 |  -4.8  23.4  280  28 15   7.8   4.3
 12500  -4.4  24.1  285  28 15   6.8   3.7 |  -3.6  25.5  275  26 14   7.8   4.3
 12000  -3.4  25.9  285  28 15   6.3   3.4 |  -2.5  27.5  270  25 13   8.0   4.4
 11500  -2.6  27.3  280  26 13   6.0   3.3 |  -1.3  29.7  270  23 12   8.0   4.4
 11000  -1.7  28.9  280  23 12   6.4   3.5 |  -0.1  31.8  265  21 11   7.0   3.8
 10500  -0.7  30.7  275  19 10   7.2   4.0 |   0.9  33.6  265  18  9   5.9   3.2
 10250  -0.2  31.6  275  17  9   4.3   2.3 |   1.3  34.3  265  17  9   9.6   5.3
 10000   0.0  32.0  275  16  8   5.2   2.9 |   2.2  36.0  265  15  8  10.2   5.6
  9750   0.6  33.1  275  13  7   8.9   4.9 |   2.8  37.0  260  13  7   6.8   3.8
  9500   1.2  34.2  275  11  6   8.0   4.4 |   3.3  37.9  260  12  6   8.0   4.4
  9250   1.8  35.2  275   9  4   7.8   4.3 |   3.9  39.0  255  10  5   6.8   3.7
  9000   2.3  36.1  275   7  4   8.0   4.4 |   4.4  39.9  255   9  5   7.1   3.9
  8750   3.0  37.4  275   7  4   9.1   5.0 |   5.0  41.0  250   8  4   8.4   4.6
  8500   3.6  38.5  275   6  3   8.8   4.8 |   5.6  42.1  245   7  3   7.9   4.3
  8250   4.3  39.7  275   6  3   9.6   5.2 |   6.2  43.2  240   6  3   8.7   4.8
  8000   5.1  41.2  275   6  3  10.1   5.6 |   6.8  44.2  240   5  3   9.4   5.2
  7750   5.8  42.4  275   5  3   9.4   5.2 |   7.5  45.5  240   5  3   9.1   5.0
  7500   6.5  43.7  275   5  3   9.6   5.2 |   8.2  46.8  240   5  3   9.2   5.1
  7250   7.2  45.0  275   5  3  10.5   5.8 |   8.9  48.0  240   5  3   9.9   5.4
  7000   8.0  46.4  275   5  3  10.9   6.0 |   9.7  49.5  240   5  2  10.3   5.7
  6750   8.8  47.8  275   5  3  10.0   5.5 |  10.4  50.7  240   5  2   9.7   5.3
  6500   9.6  49.3  275   5  3  10.2   5.6 |  11.1  52.0  240   5  2  10.0   5.5
  6250  10.4  50.7  275   5  2  11.2   6.2 |  11.9  53.4  240   4  2  10.6   5.8
  6000  11.2  52.2  275   5  2  10.3   5.6 |  12.7  54.9  240   4  2  10.4   5.7
  5750  12.0  53.6  275   4  2  12.7   6.9 |  13.5  56.3  240   4  2  11.0   6.0
  5500  13.2  55.8  275   4  2  22.1  12.1 |  14.4  57.9  240   4  2  14.4   7.9
________________________________________________________________________________

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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