Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 221220
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0620 MDT Wednesday, April 22, 2015

This forecast is for Wednesday, April 22, 2015:

If the trigger temperature of 60.1 F/15.6 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 949 ft/min (4.8 m/s)
   Maximum height of thermals.................. 15952 ft MSL (10667 ft AGL)

Forecast maximum temperature................... 68.0 F/20.5 C
Time of trigger temperature.................... 1145 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................. 9867 ft MSL (4582 ft AGL)
Thermal soaring outlook for Thursday 04/23..... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 14901 ft MSL (9616 ft AGL)
Wave soaring outlook for Thursday 04/23........ Poor

Remarks...

Sunrise/Sunset.................... 06:12:13 / 19:43:34 MDT
Total possible sunshine........... 13 hr 31 min 21 sec (811 min 21 sec)
Altitude of sun at 12:58:03 MDT... 62.51 degrees

Upper air data from rawinsonde observation taken on 04/22/2015 at 0600 MDT

Freezing level.................. 11343 ft MSL (6058 ft AGL)
Convective condensation level... 14306 ft MSL (9021 ft AGL)
Lifted condensation level....... 14680 ft MSL (9395 ft AGL)
Lifted index.................... -2.5
K index......................... +18.9

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -57.6 -71.7   275   36   19   3.6   2.0  104.7 220.4    48.3      M    M
 45000  -56.9 -70.4   270   37   19   2.7   1.5   81.1 178.0    37.3      M    M
 40000  -63.9 -83.0   270   23   12   4.0   2.2   46.9 116.4    17.6      M    M
 38000  -63.3 -81.9   280   16    8   7.6   4.2   38.9 102.1    12.7      M    M
 36000  -59.2 -74.6   295   17    9   6.9   3.8   36.4  97.6    11.4      M    M
 34000  -54.5 -66.1   305   21   11   6.8   3.7   33.7  92.6     9.8      M    M
 32000  -49.8 -57.6   295   21   11   8.7   4.8   32.1  89.7     8.8      M    M
 30000  -45.5 -49.9   270   24   12   7.6   4.1   30.0  86.0     7.5      M    M
 29000  -43.4 -46.1   280   25   13   6.5   3.6   28.9  84.0     6.7      M    M
 28000  -41.3 -42.3   290   27   14   7.2   3.9   27.8  82.1     6.0      M    M
 27000  -39.2 -38.6   285   26   13   6.2   3.4   26.7  80.1     5.2      M    M
 26000  -37.3 -35.1   280   25   13   7.9   4.3   25.5  77.9     4.3      M    M
 25000  -34.7 -30.5   275   25   13   8.7   4.8   25.1  77.1     4.0      M    M
 24000  -32.0 -25.6   275   22   11   9.2   5.0   24.8  76.7     3.9      M    M
 23000  -29.2 -20.6   280   22   11   9.2   5.1   24.6  76.2     3.7      M    M
 22000  -26.5 -15.7   285   22   11   9.0   4.9   24.4  75.9     3.6      M    M
 21000  -23.9 -11.0   285   22   11   8.7   4.8   24.0  75.2     3.3      M    M
 20000  -21.2  -6.2   285   22   11   8.3   4.6   23.7  74.6     3.0      M    M
 19500  -20.2  -4.4   280   19   10   6.2   3.4   23.2  73.7     2.6      M    M
 19000  -19.3  -2.7   275   16    8   6.9   3.8   22.6  72.6     2.1      M    M
 18500  -18.1  -0.6   275   16    8   8.2   4.5   22.3  72.1     1.8      M    M
 18000  -16.9   1.6   285   17    9   7.8   4.3   21.9  71.4     1.5      M    M
 17500  -15.8   3.6   285   17    9   7.5   4.1   21.5  70.7     1.2      M    M
 17000  -14.7   5.5   285   18    9   7.5   4.1   21.1  70.0     0.8      M    M
 16500  -13.0   8.6   285   19   10   7.6   4.2   20.6  69.0     0.3      M    M
 16000  -11.9  10.6   285   20   10   7.9   4.3   20.2  68.4    -0.0    943  4.8
 15500  -10.7  12.7   285   23   12   8.8   4.8   20.0  68.1    -0.2    890  4.5
 15000   -9.4  15.1   285   26   13   8.7   4.8   19.9  67.8    -0.4    836  4.2
 14500   -8.1  17.4   280   25   13   8.7   4.8   19.8  67.6    -0.5    783  4.0
 14000   -6.8  19.8   275   24   12   8.7   4.8   19.6  67.3    -0.7    729  3.7
 13500   -5.5  22.1   275   22   11   8.7   4.8   19.4  67.0    -0.9    675  3.4
 13000   -4.2  24.4   275   20   10   8.7   4.8   19.2  66.6    -1.0    621  3.2
 12500   -2.9  26.8   275   18    9   8.7   4.8   19.1  66.4    -1.2    568  2.9
 12000   -1.6  29.1   275   16    8   8.7   4.8   19.0  66.1    -1.3    514  2.6
 11500   -0.3  31.5   275   14    7   8.7   4.8   18.8  65.8    -1.5    460  2.3
 11000    1.0  33.8   275   13    7   8.8   4.8   18.6  65.5    -1.7    406  2.1
 10500    2.3  36.1   260   12    6   9.7   5.3   18.4  65.1    -1.9    353  1.8
 10250    3.0  37.4   255   12    6   5.2   2.9   18.3  64.9    -2.0    326  1.7
 10000    3.0  37.4   260   13    7   0.7   0.4   17.7  63.8    -2.7    317  1.6
  9750    3.1  37.6   245   12    6   1.8   1.0   17.0  62.6    -3.4    306  1.6
  9500    3.3  37.9   230   11    6   4.2   2.3   16.4  61.6    -4.0    294  1.5
  9250    3.7  38.7   220   11    6   6.2   3.4   16.1  61.0    -4.3    274  1.4
  9000    4.1  39.4   205   12    6   5.7   3.1   15.8  60.5    -4.6    254  1.3
  8750    4.5  40.1   205   13    7   5.8   3.2   15.5  59.9    -4.9    234  1.2
  8500    5.0  41.0   200   14    7   5.8   3.2   15.2  59.4    -5.2    214  1.1
  8250    5.4  41.7   200   15    8   5.8   3.2   14.9  58.8    -5.6    194  1.0
  8000    5.8  42.4   200   16    8   5.8   3.2   14.6  58.3    -5.9    174  0.9
  7750    6.2  43.2   200   17    9   6.0   3.3   14.3  57.7    -6.2    154  0.8
  7500    6.7  44.1   195   17    9   5.3   2.9   14.0  57.2    -6.5    134  0.7
  7250    7.1  44.8   195   18    9   7.7   4.2   13.7  56.6    -6.9    114  0.6
  7000    7.3  45.1   195   19   10  -7.7  -4.2   13.2  55.8    -7.3     98  0.5
  6750    6.3  43.3   200   16    8  -7.3  -4.0   11.4  52.6    -9.1    121  0.6
  6500    6.6  43.9   205   12    6   7.6   4.2   11.0  51.8    -9.6    105  0.5
  6250    7.1  44.8   210    9    5   7.8   4.3   10.7  51.3    -9.9     83  0.4
  6000    7.6  45.7   225    6    3  -1.1  -0.6   10.5  50.8   -10.1     62  0.3
  5750    7.0  44.6   235    5    3  -5.5  -3.0    9.2  48.5   -11.4     71  0.4
  5500    7.1  44.8   240    5    2   4.5   2.4    8.5  47.3   -12.2     62  0.3

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

           04/22/2015 at 0900 MDT          |       04/22/2015 at 1200 MDT
                                           |
K index... +17.0  LI... +273.1             | K index... +13.7  LI... +271.3
CAPE... 0.0  CIN... -5.7                   | CAPE... +257.2  CIN... -63.7
                                           |
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 -58.5 -73.3  275  35 18   0.9   0.5 | -58.3 -72.9  270  35 18   1.1   0.6
 45000 -57.2 -71.0  270  43 22   1.4   0.8 | -56.7 -70.1  275  38 19   1.6   0.9
 40000 -62.2 -80.0  260  20 10  -3.5  -1.9 | -61.7 -79.1  250  24 12  -3.4  -1.9
 38000 -62.1 -79.8  255  13  7   5.9   3.3 | -61.2 -78.2  240  19 10   5.5   3.0
 36000 -58.6 -73.5  275  10  5   5.8   3.2 | -58.0 -72.4  240  14  7   5.4   3.0
 34000 -54.4 -65.9  295   9  5   7.8   4.3 | -54.5 -66.1  235  10  5   7.8   4.3
 32000 -49.8 -57.6  285  11  6   7.7   4.2 | -50.0 -58.0  250  11  6   7.6   4.2
 30000 -45.2 -49.4  280  14  7   7.2   4.0 | -45.5 -49.9  260  13  7   7.0   3.9
 29000 -43.0 -45.4  280  16  8   7.3   4.0 | -43.3 -45.9  260  14  7   7.1   3.9
 28000 -40.8 -41.4  280  18  9   7.3   4.0 | -40.7 -41.3  260  16  8   7.1   3.9
 27000 -38.6 -37.5  280  20 10   7.6   4.2 | -38.5 -37.3  265  18  9   7.9   4.3
 26000 -36.3 -33.3  280  20 10   7.9   4.3 | -36.1 -33.0  265  18  9   8.1   4.5
 25000 -33.9 -29.0  285  19 10   7.9   4.3 | -33.7 -28.7  270  19 10   8.2   4.5
 24000 -31.5 -24.7  285  19 10   8.0   4.4 | -31.3 -24.3  275  19 10   8.4   4.6
 23000 -29.1 -20.4  285  19 10   8.1   4.4 | -28.7 -19.7  275  19 10   8.6   4.7
 22000 -26.7 -16.1  285  18  9   8.1   4.4 | -26.1 -15.0  280  18  9   8.6   4.7
 21000 -24.3 -11.7  280  18  9   8.0   4.4 | -23.6 -10.5  280  18  9   7.6   4.2
 20000 -21.9  -7.4  285  17  9   8.0   4.4 | -21.4  -6.5  285  17  9   7.6   4.1
 19500 -20.7  -5.3  285  17  9   8.0   4.4 | -20.2  -4.4  285  17  9   7.6   4.1
 19000 -19.5  -3.1  285  17  9   8.0   4.4 | -19.1  -2.4  285  17  9   7.6   4.1
 18500 -18.3  -0.9  290  16  8   8.1   4.5 | -18.0  -0.4  285  16  8   8.0   4.4
 18000 -16.5   2.3  290  16  8   8.3   4.5 | -16.8   1.8  285  16  8   8.2   4.5
 17500 -15.3   4.5  295  16  8   8.4   4.6 | -15.6   3.9  285  16  8   8.2   4.5
 17000 -14.0   6.8  295  15  8   8.5   4.6 | -14.3   6.3  290  15  8   8.3   4.6
 16500 -12.8   9.0  295  15  8   8.5   4.7 | -13.1   8.4  290  14  7   8.3   4.6
 16000 -11.5  11.3  295  15  8   8.6   4.7 | -11.8  10.8  290  14  7   8.7   4.8
 15500 -10.2  13.6  300  15  8   8.6   4.7 | -10.5  13.1  295  13  7   8.8   4.8
 15000  -8.9  16.0  300  15  8   9.3   5.1 |  -8.6  16.5  295  13  6   8.5   4.7
 14500  -7.5  18.5  300  16  8   9.3   5.1 |  -7.4  18.7  300  12  6   8.5   4.6
 14000  -6.1  21.0  300  16  8   9.6   5.3 |  -6.1  21.0  305  12  6   9.3   5.1
 13500  -4.7  23.5  300  16  8   9.6   5.3 |  -4.7  23.5  305  12  6   9.4   5.2
 13000  -3.3  26.1  300  17  9   9.2   5.0 |  -3.3  26.1  310  12  6   9.1   5.0
 12500  -2.0  28.4  300  17  9   8.9   4.9 |  -2.0  28.4  315  12  6   9.0   5.0
 12000  -0.7  30.7  300  16  8   8.9   4.9 |  -0.6  30.9  315  13  7   9.1   5.0
 11500   0.7  33.3  295  16  8   8.8   4.8 |   0.7  33.3  320  13  7   9.1   5.0
 11000   2.0  35.6  295  15  8   7.6   4.2 |   2.1  35.8  320  13  7   8.7   4.8
 10500   3.0  37.4  295  14  7   5.9   3.2 |   3.3  37.9  320  13  7   7.9   4.3
 10250   3.4  38.1  295  13  7   9.0   4.9 |   3.9  39.0  320  13  7  11.0   6.0
 10000   4.2  39.6  295  12  6   9.4   5.1 |   4.9  40.8  320  13  7  11.0   6.1
  9750   4.7  40.5  290  12  6   6.4   3.5 |   5.5  41.9  320  12  6   7.9   4.3
  9500   5.2  41.4  290  11  6   7.2   4.0 |   6.1  43.0  320  12  6   8.8   4.8
  9250   5.8  42.4  285  11  5   6.9   3.8 |   6.7  44.1  320  11  6   8.3   4.5
  9000   6.2  43.2  285  10  5   6.5   3.5 |   7.3  45.1  315  11  6   7.7   4.2
  8750   6.7  44.1  275  10  5   6.2   3.4 |   7.9  46.2  315  10  5   7.4   4.1
  8500   7.1  44.8  270  10  5   6.4   3.5 |   8.4  47.1  315   9  5   7.6   4.2
  8250   7.6  45.7  260  10  5   6.3   3.5 |   9.0  48.2  315   9  4   7.1   3.9
  8000   8.0  46.4  250  10  5   5.9   3.2 |   9.5  49.1  315   8  4   5.6   3.1
  7750   8.4  47.1  245  11  5   4.6   2.5 |   9.8  49.6  320   7  3   4.6   2.5
  7500   8.7  47.7  240  11  6   4.6   2.5 |  10.1  50.2  320   6  3   4.1   2.3
  7250   9.0  48.2  235  11  6   2.9   1.6 |  10.4  50.7  320   5  2   5.3   2.9
  7000   9.1  48.4  235  11  6   1.0   0.6 |  10.8  51.4  320   3  2   6.6   3.6
  6750   9.1  48.4  230  11  6  -0.3  -0.2 |  11.2  52.2  325   3  1   7.1   3.9
  6500   9.0  48.2  235  10  5  -2.4  -1.3 |  11.7  53.1  330   2  1   8.6   4.7
  6250   8.8  47.8  235   9  5  -3.2  -1.7 |  12.4  54.3  335   2  1  10.5   5.8
  6000   8.4  47.1  235   8  4  -4.3  -2.3 |  13.2  55.8  335   2  1  11.6   6.4
  5750   8.1  46.6  235   6  3  -2.0  -1.1 |  14.0  57.2  335   2  1   9.9   5.4
  5500   8.2  46.8  230   4  2   9.2   5.0 |  14.8  58.6  330   2  1  14.3   7.9

           04/22/2015 at 1500 MDT          |       04/22/2015 at 1800 MDT
                                           |
K index... +14.1  LI... +271.0             | K index... +17.7  LI... +271.8
CAPE... +232.3  CIN... -19.0               | CAPE... +169.0  CIN... -97.5
                                           |
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 -58.5 -73.3  270  37 19   1.0   0.5 | -58.7 -73.7  265  37 19   1.1   0.6
 45000 -56.9 -70.4  265  38 20  -0.3  -0.1 | -56.9 -70.4  260  42 22  -0.2  -0.1
 40000 -59.6 -75.3  260  29 15  -1.8  -1.0 | -59.4 -74.9  260  38 19  -1.6  -0.9
 38000 -59.2 -74.6  255  25 13   3.3   1.8 | -59.1 -74.4  260  36 19   2.6   1.4
 36000 -57.3 -71.1  250  20 10   3.3   1.8 | -57.5 -71.5  255  36 18   2.6   1.4
 34000 -54.9 -66.8  245  18  9   8.2   4.5 | -55.5 -67.9  255  35 18   8.6   4.7
 32000 -50.3 -58.5  255  23 12   7.7   4.2 | -50.7 -59.3  255  33 17   8.0   4.4
 30000 -45.0 -49.0  260  28 14   8.6   4.7 | -45.0 -49.0  255  29 15   9.3   5.1
 29000 -42.4 -44.3  265  28 14   8.6   4.7 | -42.3 -44.1  260  28 14   9.3   5.1
 28000 -39.8 -39.6  265  28 15   8.6   4.7 | -39.5 -39.1  265  26 13   9.3   5.1
 27000 -37.3 -35.1  270  28 15   8.0   4.4 | -36.7 -34.1  270  25 13   8.6   4.7
 26000 -35.0 -31.0  270  27 14   7.8   4.3 | -34.2 -29.6  275  24 12   8.4   4.6
 25000 -32.6 -26.7  275  25 13   7.8   4.3 | -31.7 -25.1  275  24 12   8.4   4.6
 24000 -30.3 -22.5  280  23 12   7.9   4.3 | -29.2 -20.6  280  23 12   8.0   4.4
 23000 -27.9 -18.2  285  21 11   7.9   4.3 | -26.9 -16.4  285  22 11   7.6   4.2
 22000 -25.6 -14.1  285  19 10   7.9   4.3 | -24.7 -12.5  290  21 11   7.6   4.2
 21000 -23.3  -9.9  290  18  9   7.6   4.2 | -22.4  -8.3  290  20 10   7.4   4.1
 20000 -21.0  -5.8  290  18  9   7.5   4.1 | -20.3  -4.5  295  19 10   7.4   4.1
 19500 -19.9  -3.8  295  18  9   7.5   4.1 | -19.2  -2.6  295  18  9   7.4   4.1
 19000 -18.7  -1.7  295  18  9   7.5   4.1 | -18.1  -0.6  295  17  9   7.4   4.1
 18500 -17.6   0.3  295  18  9   8.0   4.4 | -17.0   1.4  295  17  9   7.5   4.1
 18000 -16.4   2.5  295  17  9   8.2   4.5 | -15.9   3.4  295  15  8   7.6   4.2
 17500 -15.2   4.6  295  16  8   8.3   4.5 | -14.7   5.5  300  13  6   7.6   4.2
 17000 -13.9   7.0  300  15  8   8.7   4.8 | -13.6   7.5  295  10  5   7.7   4.2
 16500 -12.6   9.3  300  14  7   8.6   4.7 | -12.5   9.5  295   8  4   7.6   4.2
 16000 -10.7  12.7  300  12  6   8.9   4.9 | -10.7  12.7  280   4  2   8.3   4.6
 15500  -9.4  15.1  300  11  6   8.9   4.9 |  -9.5  14.9  240   2  1   8.3   4.5
 15000  -8.1  17.4  305  10  5   8.5   4.7 |  -8.3  17.1  190   3  1   8.5   4.6
 14500  -6.8  19.8  305   9  5   8.6   4.7 |  -7.0  19.4  170   4  2   8.4   4.6
 14000  -5.6  21.9  305   7  4   8.7   4.8 |  -5.7  21.7  165   5  3   9.1   5.0
 13500  -4.3  24.3  310   6  3   8.7   4.8 |  -4.3  24.3  160   6  3   9.2   5.0
 13000  -3.0  26.6  315   4  2   8.6   4.7 |  -2.9  26.8  155   7  3   9.0   5.0
 12500  -1.7  28.9  315   3  2   8.5   4.7 |  -1.6  29.1  155   6  3   9.0   4.9
 12000  -0.4  31.3  315   2  1   8.5   4.7 |  -0.3  31.5  150   6  3   8.9   4.9
 11500   0.8  33.4  335   1  1   8.6   4.7 |   1.0  33.8  150   5  3   8.9   4.9
 11000   2.1  35.8  005   1  0   8.1   4.4 |   2.3  36.1  155   4  2   8.3   4.5
 10500   3.2  37.8  020   1  0   7.1   3.9 |   3.5  38.3  155   3  2   7.3   4.0
 10250   3.8  38.8  030   1  1  10.4   5.7 |   4.1  39.4  160   3  1   9.6   5.2
 10000   4.7  40.5  035   1  0  11.4   6.2 |   4.9  40.8  170   2  1  10.1   5.5
  9750   5.3  41.5  030   1  0   8.8   4.8 |   5.5  41.9  190   2  1   8.2   4.5
  9500   6.0  42.8  020   1  0   9.6   5.3 |   6.1  43.0  220   1  1   8.7   4.8
  9250   6.6  43.9  010   1  0   9.5   5.2 |   6.8  44.2  250   2  1   8.8   4.8
  9000   7.3  45.1  360   1  0   9.7   5.3 |   7.4  45.3  270   2  1   8.5   4.7
  8750   8.0  46.4  355   1  0   9.8   5.4 |   8.0  46.4  275   3  2   7.9   4.4
  8500   8.7  47.7  355   1  0   9.5   5.2 |   8.6  47.5  280   4  2   8.1   4.4
  8250   9.5  49.1  350   1  0  10.6   5.8 |   9.2  48.6  280   5  3   8.1   4.4
  8000  10.3  50.5  340   1  1  10.9   6.0 |   9.8  49.6  280   7  3   7.6   4.2
  7750  11.0  51.8  335   1  1   9.4   5.2 |  10.3  50.5  280   8  4   6.9   3.8
  7500  11.7  53.1  330   1  1   8.7   4.8 |  10.8  51.4  280   9  5   7.0   3.8
  7250  12.4  54.3  325   1  1  10.4   5.7 |  11.3  52.3  275  10  5   6.3   3.4
  7000  13.2  55.8  325   1  1  11.7   6.4 |  11.7  53.1  275  12  6   5.3   2.9
  6750  14.0  57.2  325   1  1   9.8   5.4 |  12.1  53.8  270  14  7   4.5   2.5
  6500  14.7  58.5  320   1  1   9.4   5.2 |  12.4  54.3  270  15  8   4.0   2.2
  6250  15.5  59.9  320   1  1  10.6   5.8 |  12.7  54.9  270  16  8   5.4   2.9
  6000  16.3  61.3  320   1  1  11.5   6.3 |  13.0  55.4  265  15  8   6.4   3.5
  5750  17.1  62.8  320   2  1   9.5   5.2 |  13.3  55.9  265  14  7   6.1   3.4
  5500  17.8  64.0  320   2  1  12.6   6.9 |  13.7  56.7  265  13  7   8.6   4.7
________________________________________________________________________________

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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