Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 301231
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0631 MDT Thursday, April 30, 2015

This forecast is for Thursday, April 30, 2015:

If the trigger temperature of 72.9 F/22.7 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 746 ft/min (3.8 m/s)
   Maximum height of thermals.................. 17227 ft MSL (11942 ft AGL)

Forecast maximum temperature................... 78.0 F/26.0 C
Time of trigger temperature.................... 1100 MDT
Time of overdevelopment........................ 1500 MDT
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8297 ft MSL (3011 ft AGL)
Thermal soaring outlook for Friday 05/01....... Poor

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 17329 ft MSL (12044 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Weak PVA
Potential height of wave....................... 17821 ft MSL (12536 ft AGL)
Wave soaring outlook for Friday 05/01.......... Poor

Remarks... None

Sunrise/Sunset.................... 06:01:36 / 19:51:37 MDT
Total possible sunshine........... 13 hr 50 min 1 sec (830 min 1 sec)
Altitude of sun at 12:56:47 MDT... 65.08 degrees

Upper air data from rawinsonde observation taken on 04/30/2015 at 0600 MDT

Freezing level.................. 13093 ft MSL (7808 ft AGL)
Convective condensation level... 19042 ft MSL (13757 ft AGL)
Lifted condensation level....... 17876 ft MSL (12590 ft AGL)
Lifted index.................... +1.6
K index......................... +16.9

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  -62.5 -80.5   270   22   11   3.4   1.8   93.2 199.8    38.9      M    M
 45000  -60.7 -77.3   245   22   11  -0.2  -0.1   71.7 161.0    28.4      M    M
 40000  -63.2 -81.8   255   29   15   4.9   2.7   43.9 111.0    12.1      M    M
 38000  -58.3 -72.9   250   33   17   8.3   4.6   42.7 108.8    11.6      M    M
 36000  -53.3 -63.9   255   29   15   8.3   4.6   41.2 106.2    11.0      M    M
 34000  -48.1 -54.6   255   26   13   7.9   4.3   40.5 104.9    10.7      M    M
 32000  -43.5 -46.3   260   26   13   7.2   3.9   38.7 101.7     9.7      M    M
 30000  -39.0 -38.2   275   24   13   9.5   5.2   36.9  98.5     8.6      M    M
 29000  -35.4 -31.7   280   23   12   9.5   5.2   36.8  98.3     8.6      M    M
 28000  -33.0 -27.4   280   23   12   6.1   3.3   36.1  97.0     8.2      M    M
 27000  -31.1 -24.0   285   22   11   8.7   4.8   34.9  94.9     7.4      M    M
 26000  -28.6 -19.5   280   20   10   8.4   4.6   34.4  93.9     7.0      M    M
 25000  -26.1 -15.0   270   19   10   8.5   4.7   33.9  93.1     6.7      M    M
 24000  -23.9 -11.0   285   18    9   7.3   4.0   33.0  91.5     6.1      M    M
 23000  -21.7  -7.1   300   18    9   7.3   4.0   32.2  89.9     5.4      M    M
 22000  -19.5  -3.1   300   14    7   7.3   4.0   31.2  88.1     4.6      M    M
 21000  -17.4   0.7   295   11    6   7.3   4.0   30.3  86.6     4.0      M    M
 20000  -15.0   5.0   290    7    4   8.3   4.5   29.8  85.6     3.5      M    M
 19500  -13.7   7.3   305    5    3   8.3   4.5   29.5  85.1     3.3      M    M
 19000  -12.5   9.5   330    4    2   8.4   4.6   29.2  84.6     3.1      M    M
 18500  -11.2  11.8   350    5    3   9.7   5.3   29.1  84.3     3.0      M    M
 18000  -10.2  13.6   355    7    4   2.9   1.6   28.5  83.3     2.5      M    M
 17500   -9.8  14.4   355    9    4   3.0   1.7   27.3  81.2     1.4      M    M
 17000  -10.7  12.7   360   10    5  -6.0  -3.3   24.8  76.6    -0.9   1158  5.9
 16500   -9.8  14.4   360   12    6   9.9   5.4   24.2  75.5    -1.5   1116  5.7
 16000   -8.4  16.9   360   14    7   6.6   3.6   24.2  75.5    -1.5   1058  5.4
 15500   -7.4  18.7   360   15    8  10.4   5.7   23.7  74.7    -2.0   1014  5.2
 15000   -6.0  21.2   360   17    9   9.7   5.3   23.7  74.7    -2.1    956  4.9
 14500   -3.8  25.2   005   15    7   9.7   5.3   23.7  74.7    -2.1    869  4.4
 14000   -2.3  27.9   005   13    7   9.7   5.3   23.7  74.7    -2.1    811  4.1
 13500   -0.9  30.4   010   12    6   9.7   5.3   23.7  74.6    -2.2    753  3.8
 13000    0.6  33.1   010   12    6   9.7   5.3   23.6  74.5    -2.2    694  3.5
 12500    2.0  35.6   015   11    6   9.7   5.3   23.6  74.5    -2.2    636  3.2
 12000    3.4  38.1   015   11    6   9.4   5.2   23.6  74.5    -2.2    579  2.9
 11500    4.8  40.6   015    9    5   9.4   5.2   23.5  74.4    -2.3    522  2.7
 11000    6.2  43.2   015    8    4   9.4   5.2   23.5  74.3    -2.4    465  2.4
 10500    7.6  45.7   010    7    3   9.5   5.2   23.4  74.2    -2.5    409  2.1
 10250    8.3  46.9   010    6    3   9.2   5.1   23.4  74.2    -2.5    381  1.9
 10000    9.0  48.2   005    6    3   8.9   4.9   23.4  74.1    -2.6    353  1.8
  9750    9.6  49.3   360    7    4   8.9   4.9   23.3  74.0    -2.6    326  1.7
  9500   10.3  50.5   355    8    4   8.9   4.9   23.3  73.9    -2.7    298  1.5
  9250   11.0  51.8   350    8    4   8.9   4.9   23.2  73.8    -2.7    271  1.4
  9000   11.6  52.9   345    9    5   8.9   4.9   23.2  73.7    -2.8    244  1.2
  8750   12.3  54.1   345    8    4   8.9   4.9   23.1  73.6    -2.9    216  1.1
  8500   13.0  55.4   340    6    3   8.9   4.9   23.0  73.4    -3.0    189  1.0
  8250   13.6  56.5   335    5    3   8.9   4.9   23.0  73.3    -3.0    162  0.8
  8000   14.3  57.7   330    4    2   8.9   4.9   22.9  73.2    -3.1    134  0.7
  7750   15.0  59.0   325    5    3   9.2   5.0   22.8  73.1    -3.2    107  0.5
  7500   15.6  60.1   320    6    3   8.1   4.4   22.8  73.0    -3.2     79  0.4
  7250   16.1  61.0   315    8    4   4.8   2.6   22.5  72.5    -3.5     58  0.3
  7000   16.4  61.5   315    9    5   3.4   1.9   22.1  71.7    -3.9     42  0.2
  6750   16.7  62.1   305    8    4   3.7   2.0   21.6  70.9    -4.4     27  0.1
  6500   16.9  62.4   295    8    4   4.1   2.3   21.1  70.1    -4.9     11  0.1
  6250   17.2  63.0   285    8    4   2.1   1.2   20.7  69.2    -5.4      M    M
  6000   17.1  62.8   270    8    4  -4.5  -2.5   19.9  67.8    -6.2      M    M
  5750   16.2  61.2   250    6    3 -23.2 -12.7   18.3  64.9    -7.9     12  0.1
  5500   13.4  56.1   220    5    3 -46.1 -25.3   14.8  58.7   -11.4     89  0.5

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

           04/30/2015 at 0900 MDT          |       04/30/2015 at 1200 MDT
                                           |
K index... +20.3  LI... +274.3             | K index... +17.4  LI... +271.5
CAPE... 0.0  CIN... M                      | CAPE... +54.3  CIN... -17.8
                                           |
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 -61.5 -78.7  250  21 11   1.8   1.0 | -62.6 -80.7  235  24 12   1.7   0.9
 45000 -59.1 -74.4  245  30 16  -1.6  -0.9 | -60.3 -76.5  240  33 17  -0.7  -0.4
 40000 -61.4 -78.5  255  23 12  -1.9  -1.0 | -61.2 -78.2  255  25 13  -1.1  -0.6
 38000 -58.0 -72.4  255  24 12   7.4   4.1 | -57.7 -71.9  255  26 13   7.2   4.0
 36000 -53.5 -64.3  255  26 13   7.4   4.1 | -53.4 -64.1  255  27 14   7.2   4.0
 34000 -48.9 -56.0  260  26 14   8.0   4.4 | -48.8 -55.8  255  28 14   8.0   4.4
 32000 -44.1 -47.4  270  25 13   8.0   4.4 | -44.0 -47.2  260  27 14   8.0   4.4
 30000 -38.7 -37.7  275  23 12   8.1   4.4 | -39.3 -38.7  265  26 13   7.8   4.3
 29000 -36.2 -33.2  280  23 12   8.1   4.4 | -36.3 -33.3  270  25 13   7.8   4.3
 28000 -33.8 -28.8  280  22 11   8.1   4.5 | -34.0 -29.2  275  24 13   7.8   4.3
 27000 -31.4 -24.5  285  21 11   8.2   4.5 | -31.6 -24.9  275  24 12   8.0   4.4
 26000 -28.9 -20.0  285  21 11   8.2   4.5 | -29.2 -20.6  280  23 12   8.0   4.4
 25000 -26.5 -15.7  285  21 11   8.2   4.5 | -26.8 -16.2  280  22 11   8.0   4.4
 24000 -24.1 -11.4  285  20 10   8.1   4.4 | -24.4 -11.9  280  21 11   8.2   4.5
 23000 -21.6  -6.9  285  18 10   8.1   4.4 | -22.0  -7.6  280  21 11   8.2   4.5
 22000 -19.2  -2.6  285  17  9   8.0   4.4 | -19.5  -3.1  280  20 10   8.1   4.4
 21000 -17.1   1.2  285  15  7   6.0   3.3 | -17.6   0.3  280  19 10   4.8   2.6
 20000 -15.3   4.5  285  11  6   6.0   3.3 | -16.2   2.8  280  17  9   4.7   2.6
 19500 -14.5   5.9  290  10  5   6.0   3.3 | -15.6   3.9  280  17  9   4.8   2.6
 19000 -13.6   7.5  295   8  4   5.9   3.3 | -14.9   5.2  285  16  8   5.4   3.0
 18500 -12.8   9.0  300   7  4   5.4   3.0 | -13.7   7.3  285  14  7   9.0   5.0
 18000 -12.0  10.4  315   7  3   5.5   3.0 | -12.5   9.5  285  12  6   8.9   4.9
 17500 -11.2  11.8  325   7  3   6.0   3.3 | -11.2  11.8  290  11  5   8.6   4.7
 17000 -10.3  13.5  335   7  3   6.2   3.4 |  -9.9  14.2  285  10  5   8.5   4.7
 16500  -9.4  15.1  340   7  4   6.7   3.7 |  -8.7  16.3  280   9  4   8.5   4.7
 16000  -8.3  17.1  345   7  4   8.3   4.6 |  -7.4  18.7  280   8  4   8.4   4.6
 15500  -6.5  20.3  345   8  4   8.8   4.8 |  -5.6  21.9  280   7  4   8.5   4.7
 15000  -5.1  22.8  350   8  4   9.4   5.2 |  -4.3  24.3  280   6  3   8.5   4.7
 14500  -3.7  25.3  350   8  4   9.5   5.2 |  -3.1  26.4  285   5  3   8.6   4.7
 14000  -2.3  27.9  350   8  4   9.7   5.3 |  -1.8  28.8  285   5  2   8.7   4.8
 13500  -0.9  30.4  350   8  4   9.7   5.3 |  -0.5  31.1  290   4  2   8.8   4.8
 13000   0.6  33.1  350   8  4   9.7   5.3 |   0.8  33.4  295   4  2   9.0   5.0
 12500   2.0  35.6  350   9  4   9.7   5.3 |   2.1  35.8  300   5  2   9.0   4.9
 12000   3.4  38.1  350   9  4   9.4   5.1 |   3.5  38.3  305   5  3   9.3   5.1
 11500   4.8  40.6  350   9  4   9.6   5.2 |   4.8  40.6  305   5  3   9.3   5.1
 11000   6.1  43.0  350   9  5   7.6   4.2 |   6.3  43.3  310   6  3   9.7   5.3
 10500   7.3  45.1  345   9  5   6.7   3.7 |   7.7  45.9  315   7  4  10.6   5.8
 10250   7.9  46.2  345   9  5  11.6   6.4 |   8.4  47.1  315   7  4   6.0   3.3
 10000   8.9  48.0  345  10  5  12.3   6.8 |   8.7  47.7  320   7  4   6.6   3.6
  9750   9.6  49.3  345  10  5   8.0   4.4 |   9.5  49.1  320   8  4  11.6   6.3
  9500  10.3  50.5  345  10  5   9.2   5.0 |  10.3  50.5  325   8  4  10.5   5.7
  9250  10.9  51.6  345  10  5   8.7   4.7 |  11.0  51.8  325   8  4   8.9   4.9
  9000  11.6  52.9  345  10  5   9.3   5.1 |  11.6  52.9  325   8  4   8.7   4.8
  8750  12.3  54.1  340  10  5   9.9   5.4 |  12.3  54.1  325   8  4  10.3   5.7
  8500  13.0  55.4  340  10  5   9.7   5.3 |  13.1  55.6  325   8  4   9.9   5.4
  8250  13.8  56.8  340  11  5   9.9   5.4 |  13.8  56.8  325   8  4  10.3   5.7
  8000  14.5  58.1  335  11  6   9.4   5.2 |  14.5  58.1  325   7  4  10.1   5.5
  7750  15.2  59.4  330  12  6   8.6   4.7 |  15.3  59.5  325   7  4   9.5   5.2
  7500  15.8  60.4  330  12  6   8.4   4.6 |  16.0  60.8  325   7  4   9.7   5.3
  7250  16.5  61.7  325  13  7   8.2   4.5 |  16.7  62.1  325   7  4  10.0   5.5
  7000  17.0  62.6  320  14  7   7.6   4.2 |  17.5  63.5  325   7  4  10.1   5.5
  6750  17.6  63.7  315  15  8   8.2   4.5 |  18.2  64.8  325   7  4   9.9   5.4
  6500  18.1  64.6  310  17  9   3.1   1.7 |  18.9  66.0  325   7  4  10.4   5.7
  6250  18.0  64.4  305  15  8  -2.6  -1.4 |  19.7  67.5  325   7  3  11.0   6.0
  6000  17.8  64.0  295  14  7  -1.5  -0.8 |  20.5  68.9  325   7  3  10.3   5.6
  5750  17.4  63.3  290  12  6  -8.5  -4.7 |  21.3  70.3  325   7  3  12.0   6.6
  5500  16.3  61.3  270   8  4 -15.2  -8.3 |  22.5  72.5  325   6  3  19.4  10.7

           04/30/2015 at 1500 MDT          |       04/30/2015 at 1800 MDT
                                           |
K index... +19.8  LI... +271.4             | K index... +23.9  LI... +271.7
CAPE... +132.7  CIN... -29.0               | CAPE... +258.4  CIN... -12.8
                                           |
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 -61.7 -79.1  235  29 15   1.5   0.8 | -61.7 -79.1  250  30 16   1.7   0.9
 45000 -59.7 -75.5  245  37 19  -1.5  -0.8 | -59.5 -75.1  260  34 18  -2.1  -1.2
 40000 -61.8 -79.2  255  31 16  -1.9  -1.0 | -62.4 -80.3  260  40 20  -2.4  -1.3
 38000 -58.2 -72.8  260  32 17   7.6   4.2 | -58.8 -73.8  260  39 20   7.8   4.3
 36000 -53.6 -64.5  260  34 17   7.6   4.2 | -54.1 -65.4  265  38 20   7.8   4.3
 34000 -48.9 -56.0  265  35 18   8.1   4.5 | -49.4 -56.9  270  37 19   7.9   4.3
 32000 -44.0 -47.2  265  35 18   8.1   4.5 | -44.7 -48.5  275  34 18   7.9   4.3
 30000 -38.7 -37.7  270  33 17   7.6   4.2 | -39.7 -39.5  285  33 17   8.8   4.8
 29000 -36.5 -33.7  275  32 16   7.7   4.2 | -36.5 -33.7  285  32 16   8.8   4.8
 28000 -34.2 -29.6  275  30 16   7.7   4.2 | -33.8 -28.8  290  31 16   8.9   4.9
 27000 -31.9 -25.4  280  29 15   7.9   4.3 | -31.4 -24.5  290  29 15   7.9   4.3
 26000 -29.5 -21.1  280  28 14   7.9   4.3 | -29.0 -20.2  285  27 14   7.9   4.3
 25000 -27.1 -16.8  280  27 14   7.9   4.3 | -26.7 -16.1  285  25 13   7.9   4.3
 24000 -24.8 -12.6  280  27 14   7.7   4.2 | -24.4 -11.9  280  24 12   7.8   4.3
 23000 -22.5  -8.5  285  27 14   7.7   4.3 | -22.1  -7.8  275  22 12   7.8   4.3
 22000 -20.2  -4.4  285  27 14   7.7   4.2 | -19.8  -3.6  270  22 11   7.9   4.3
 21000 -18.1  -0.6  285  26 13   6.7   3.7 | -17.5   0.5  265  20 10   7.5   4.1
 20000 -16.1   3.0  285  23 12   6.7   3.7 | -15.3   4.5  265  18  9   7.5   4.1
 19500 -15.2   4.6  285  22 11   6.7   3.7 | -14.2   6.4  265  17  9   7.5   4.1
 19000 -14.2   6.4  285  20 10   6.9   3.8 | -13.1   8.4  265  16  8   7.4   4.0
 18500 -13.0   8.6  290  18  9   7.9   4.4 | -12.1  10.2  270  15  8   6.4   3.5
 18000 -11.9  10.6  290  17  9   7.9   4.3 | -11.2  11.8  275  14  7   6.4   3.5
 17500 -10.7  12.7  295  16  8   8.4   4.6 | -10.2  13.6  275  13  7   7.3   4.0
 17000  -9.4  15.1  295  15  8   8.5   4.6 |  -9.1  15.6  275  13  6   7.5   4.1
 16500  -8.2  17.2  300  15  8   8.5   4.7 |  -8.0  17.6  275  12  6   7.6   4.2
 16000  -6.9  19.6  300  13  7   8.6   4.7 |  -6.9  19.6  265  10  5   7.7   4.2
 15500  -5.0  23.0  295   9  5   8.7   4.8 |  -5.7  21.7  255   8  4   7.7   4.2
 15000  -3.7  25.3  295   7  4   8.8   4.8 |  -4.0  24.8  240   5  3   7.7   4.2
 14500  -2.3  27.9  295   5  3   8.7   4.8 |  -2.9  26.8  230   4  2   7.8   4.3
 14000  -1.1  30.0  300   4  2   8.5   4.6 |  -1.7  28.9  220   3  1   7.9   4.3
 13500   0.2  32.4  315   3  1   8.5   4.7 |  -0.5  31.1  205   2  1   7.8   4.3
 13000   1.4  34.5  330   2  1   8.7   4.8 |   0.8  33.4  185   1  0   9.5   5.2
 12500   2.7  36.9  345   2  1   8.7   4.8 |   2.2  36.0  000   0  0   9.3   5.1
 12000   4.0  39.2  360   1  1   9.0   5.0 |   3.6  38.5  000   0  0   9.9   5.4
 11500   5.3  41.5  005   1  1   9.1   5.0 |   5.1  41.2  055   1  0  10.0   5.5
 11000   6.5  43.7  010   1  1   7.8   4.3 |   6.4  43.5  040   1  0   8.4   4.6
 10500   7.7  45.9  005   2  1   7.0   3.8 |   7.7  45.9  035   1  0   7.9   4.3
 10250   8.3  46.9  005   2  1  12.0   6.6 |   8.4  47.1  030   1  1  12.6   6.9
 10000   9.3  48.7  005   2  1  12.7   7.0 |   9.5  49.1  025   1  1  12.8   7.0
  9750  10.0  50.0  360   2  1   8.2   4.5 |  10.2  50.4  020   1  1   8.7   4.8
  9500  10.7  51.3  355   2  1   9.4   5.2 |  10.9  51.6  015   1  1  10.0   5.5
  9250  11.3  52.3  355   2  1   9.1   5.0 |  11.6  52.9  010   1  1   8.9   4.9
  9000  12.0  53.6  355   2  1   9.9   5.4 |  12.3  54.1  005   2  1   9.1   5.0
  8750  12.8  55.0  350   2  1  10.4   5.7 |  13.0  55.4  360   2  1   9.9   5.4
  8500  13.6  56.5  345   2  1  10.2   5.6 |  13.7  56.7  355   2  1   9.7   5.3
  8250  14.3  57.7  340   2  1  10.3   5.6 |  14.4  57.9  350   3  1   9.7   5.3
  8000  15.1  59.2  340   2  1  10.1   5.6 |  15.1  59.2  345   3  2   9.2   5.1
  7750  15.8  60.4  340   2  1  10.0   5.5 |  15.7  60.3  345   4  2   8.7   4.8
  7500  16.6  61.9  335   2  1  10.0   5.5 |  16.4  61.5  340   4  2   8.9   4.9
  7250  17.3  63.1  335   2  1  10.3   5.6 |  17.0  62.6  340   4  2   9.6   5.3
  7000  18.1  64.6  335   2  1  10.2   5.6 |  17.7  63.9  335   5  2   9.8   5.4
  6750  18.8  65.8  330   2  1   9.1   5.0 |  18.4  65.1  335   5  3   9.0   4.9
  6500  19.5  67.1  325   2  1   9.7   5.3 |  19.0  66.2  335   5  3   9.3   5.1
  6250  20.3  68.5  325   2  1  11.1   6.1 |  19.7  67.5  330   5  3  10.0   5.5
  6000  21.1  70.0  320   2  1  10.5   5.7 |  20.5  68.9  330   5  3  10.0   5.5
  5750  21.9  71.4  320   2  1  11.7   6.4 |  21.2  70.2  325   5  3   9.3   5.1
  5500  22.9  73.2  320   2  1  18.1   9.9 |  21.8  71.2  325   5  3   8.7   4.8
________________________________________________________________________________

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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