Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 150125
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1925 MDT Thursday, September 14, 2017

This forecast is for Friday, September 15, 2017:

If the trigger temperature of 71.3 F/21.8 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 912 ft/min (4.6 m/s)
   Maximum height of thermals.................. 16119 ft MSL (10812 ft AGL)

Forecast maximum temperature................... 83.0 F/28.8 C
Time of trigger temperature.................... 1030 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................. 13964 ft MSL (8657 ft AGL)
Thermal soaring outlook for Saturday 09/16..... Fair

Wave Soaring Index............................. Fair
Wave Soaring Index trend (to 1800 MDT)......... Improving
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak PVA
Potential height of wave....................... 35535 ft MSL (30228 ft AGL)
Wave soaring outlook for Saturday 09/16........ Good

Remarks...

Sunrise/Sunset.................... 06:40:49 / 19:09:06 MDT
Total possible sunshine........... 12 hr 28 min 18 sec (748 min 18 sec)
Altitude of sun at 12:54:28 MDT... 52.97 degrees

Upper air data from numerical model forecast valid on 09/15/2017 at 0600 MDT

Freezing level.................. 13514 ft MSL (8207 ft AGL)
Convective condensation level... 14544 ft MSL (9237 ft AGL)
Lifted condensation level....... 15645 ft MSL (10338 ft AGL)
Lifted index.................... -0.8
K index......................... +7.4

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  -59.8 -75.6   220   18    9   2.3   1.3      M     M       M      M    M
 45000  -56.5 -69.7   205   31   16   1.7   1.0      M     M       M      M    M
 40000  -53.8 -64.8   230   56   29   2.8   1.6      M     M       M      M    M
 38000  -51.1 -60.0   225   58   30   4.5   2.5      M     M       M      M    M
 36000  -48.3 -54.9   225   61   31   4.5   2.5      M     M       M      M    M
 34000  -44.4 -47.9   220   62   32   8.3   4.5      M     M       M      M    M
 32000  -39.4 -38.9   220   61   31   8.3   4.5      M     M       M      M    M
 30000  -33.9 -29.0   220   59   30   8.2   4.5   41.8 107.2    10.2      M    M
 29000  -31.4 -24.5   220   58   30   8.2   4.5   41.1 106.1     9.9      M    M
 28000  -28.9 -20.0   220   57   29   8.2   4.5   40.7 105.2     9.6      M    M
 27000  -26.6 -15.9   220   56   29   7.7   4.2   39.9 103.9     9.1      M    M
 26000  -24.3 -11.7   220   55   29   7.7   4.2   39.1 102.4     8.6      M    M
 25000  -22.0  -7.6   220   55   28   7.7   4.2   38.4 101.1     8.1      M    M
 24000  -19.7  -3.5   220   54   28   7.4   4.1   37.6  99.8     7.5      M    M
 23000  -17.5   0.5   220   52   27   7.4   4.1   36.7  98.1     6.9      M    M
 22000  -15.3   4.5   220   51   26   7.4   4.0   35.9  96.7     6.3      M    M
 21000  -13.2   8.2   220   49   25   6.3   3.5   34.9  94.9     5.5      M    M
 20000  -11.3  11.7   220   46   24   6.3   3.5   33.7  92.6     4.5      M    M
 19500  -10.4  13.3   220   45   23   6.3   3.5   33.1  91.6     4.0      M    M
 19000   -9.4  15.1   220   44   23   6.4   3.5   32.5  90.6     3.6      M    M
 18500   -8.5  16.7   225   43   22   6.0   3.3   31.9  89.5     3.1      M    M
 18000   -7.6  18.3   225   42   22   6.0   3.3   31.3  88.3     2.5      M    M
 17500   -6.7  19.9   225   42   21   5.8   3.2   30.7  87.2     2.0      M    M
 17000   -5.9  21.4   225   41   21   5.6   3.1   29.9  85.9     1.3      M    M
 16500   -5.1  22.8   230   40   21   5.6   3.1   29.2  84.6     0.7      M    M
 16000   -4.3  24.3   230   39   20   4.7   2.6   28.4  83.2     0.0      M    M
 15500   -3.3  26.1   235   38   20   5.1   2.8   27.2  81.0    -1.2    859  4.4
 15000   -2.5  27.5   235   37   19   6.1   3.3   26.5  79.8    -1.9    821  4.2
 14500   -1.6  29.1   240   36   19   6.0   3.3   25.9  78.7    -2.5    781  4.0
 14000   -0.8  30.6   240   35   18   6.8   3.7   25.4  77.7    -3.1    739  3.8
 13500    0.2  32.4   240   32   17   6.8   3.7   24.9  76.8    -3.6    696  3.5
 13000    1.2  34.2   240   30   15   8.1   4.4   24.5  76.1    -4.1    651  3.3
 12500    2.4  36.3   240   28   14   8.3   4.6   24.2  75.6    -4.4    601  3.1
 12000    3.6  38.5   240   26   13   9.0   4.9   24.1  75.3    -4.7    550  2.8
 11500    4.9  40.8   240   26   13   9.2   5.1   24.0  75.1    -4.8    494  2.5
 11000    6.3  43.3   240   26   13   7.2   4.0   23.8  74.9    -4.9    440  2.2
 10500    7.2  45.0   250   30   15   5.7   3.1   23.3  73.9    -5.5    398  2.0
 10250    7.6  45.7   250   32   17   8.7   4.8   23.0  73.4    -5.8    377  1.9
 10000    8.4  47.1   250   29   15   9.9   5.4   23.1  73.5    -5.8    347  1.8
  9750    9.0  48.2   250   28   15   7.7   4.2   22.9  73.3    -6.0    322  1.6
  9500    9.6  49.3   250   27   14   8.0   4.4   22.8  73.1    -6.1    297  1.5
  9250   10.1  50.2   255   26   13   9.0   4.9   22.7  72.8    -6.3    272  1.4
  9000   10.8  51.4   255   25   13   9.3   5.1   22.7  72.8    -6.3    244  1.2
  8750   11.5  52.7   255   23   12   8.5   4.7   22.6  72.6    -6.4    218  1.1
  8500   12.1  53.8   255   22   11   8.3   4.6   22.5  72.5    -6.6    192  1.0
  8250   12.7  54.9   255   20   10   9.8   5.4   22.4  72.3    -6.7    166  0.8
  8000   13.5  56.3   255   19   10  10.5   5.8   22.5  72.5    -6.7    135  0.7
  7750   14.2  57.6   255   18    9   8.7   4.7   22.5  72.4    -6.7    108  0.5
  7500   14.8  58.6   260   17    9   8.5   4.7   22.4  72.3    -6.9     82  0.4
  7250   15.4  59.7   260   16    8   8.1   4.4   22.3  72.1    -7.0     56  0.3
  7000   15.9  60.6   255   15    8   7.0   3.9   22.1  71.8    -7.2     33  0.2
  6750   16.4  61.5   255   14    7   5.6   3.1   21.8  71.3    -7.5     11  0.1
  6500   16.7  62.1   255   14    7   4.1   2.2   21.5  70.6    -7.9      M    M
  6250   16.8  62.2   250   14    7  -1.9  -1.1   20.9  69.6    -8.5      M    M
  6000   16.4  61.5   245   13    7  -5.7  -3.1   19.8  67.6    -9.7      M    M
  5750   15.9  60.6   235   13    7  -7.3  -4.0   18.6  65.5   -11.0      M    M
  5500   15.0  59.0   225   11    6 -15.1  -8.3   17.0  62.7   -12.6     16  0.1

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

           09/15/2017 at 0900 MDT          |       09/15/2017 at 1200 MDT
                                           |
K index... +3.3  LI... +3.7                | K index... +10.0  LI... +3.7
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
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 -59.3 -74.7  250  16  8   2.5   1.4 | -59.1 -74.4  220  22 11   3.0   1.7
 45000 -55.6 -68.1  240  27 14   1.9   1.0 | -54.7 -66.5  225  35 18   2.0   1.1
 40000 -52.8 -63.0  230  52 27   2.4   1.3 | -51.7 -61.1  235  54 28   2.2   1.2
 38000 -50.6 -59.1  230  56 29   3.7   2.0 | -49.9 -57.8  230  55 28   3.0   1.6
 36000 -48.5 -55.3  230  60 31   3.6   2.0 | -48.1 -54.6  230  57 29   3.0   1.6
 34000 -44.9 -48.8  230  60 31   7.9   4.3 | -45.2 -49.4  225  56 29   6.8   3.7
 32000 -40.2 -40.4  230  58 30   7.9   4.3 | -41.1 -42.0  225  52 27   6.8   3.7
 30000 -34.9 -30.8  230  53 27   7.9   4.3 | -36.2 -33.2  230  46 23   7.6   4.2
 29000 -32.5 -26.5  230  50 26   7.9   4.3 | -34.0 -29.2  230  42 21   7.6   4.2
 28000 -30.2 -22.4  230  47 24   7.9   4.3 | -31.7 -25.1  230  38 19   7.6   4.2
 27000 -27.8 -18.0  235  44 23   8.1   4.4 | -29.2 -20.6  230  35 18   8.8   4.8
 26000 -25.4 -13.7  235  41 21   8.1   4.4 | -26.6 -15.9  230  34 17   8.8   4.8
 25000 -23.0  -9.4  240  39 20   8.1   4.5 | -24.0 -11.2  225  32 17   8.8   4.8
 24000 -20.6  -5.1  240  36 19   7.7   4.2 | -21.5  -6.7  225  30 16   7.6   4.2
 23000 -18.3  -0.9  235  33 17   7.7   4.2 | -19.2  -2.6  225  27 14   7.7   4.2
 22000 -16.0   3.2  230  30 15   7.7   4.2 | -16.9   1.6  225  24 12   7.7   4.2
 21000 -13.7   7.3  230  27 14   7.8   4.3 | -14.6   5.7  230  22 11   8.0   4.4
 20000 -11.4  11.5  235  25 13   7.8   4.3 | -12.2  10.0  235  20 10   8.1   4.4
 19500 -10.3  13.5  240  25 13   7.8   4.3 | -11.0  12.2  235  19 10   8.1   4.4
 19000  -9.1  15.6  245  24 12   7.9   4.3 |  -9.8  14.4  240  19 10   8.1   4.4
 18500  -8.1  17.4  250  24 12   6.7   3.7 |  -8.6  16.5  245  18  9   8.2   4.5
 18000  -7.0  19.4  250  24 12   6.8   3.7 |  -7.4  18.7  250  17  9   8.2   4.5
 17500  -6.0  21.2  255  23 12   6.4   3.5 |  -6.2  20.8  255  17  9   7.8   4.3
 17000  -5.1  22.8  255  23 12   6.1   3.3 |  -5.1  22.8  255  17  9   7.6   4.2
 16500  -4.2  24.4  255  23 12   6.1   3.4 |  -3.9  25.0  260  17  9   7.5   4.1
 16000  -2.9  26.8  260  22 12   5.3   2.9 |  -2.5  27.5  265  17  9   6.3   3.5
 15500  -2.1  28.2  260  22 12   5.3   2.9 |  -1.5  29.3  270  16  8   6.4   3.5
 15000  -1.4  29.5  260  22 11   5.0   2.7 |  -0.5  31.1  275  17  9   6.8   3.7
 14500  -0.6  30.9  260  22 11   4.9   2.7 |   0.5  32.9  275  18  9   6.9   3.8
 14000   0.2  32.4  260  21 11   5.6   3.1 |   1.4  34.5  280  21 11   5.9   3.2
 13500   1.0  33.8  260  21 11   5.5   3.0 |   2.3  36.1  280  24 12   6.1   3.3
 13000   1.9  35.4  260  21 11   6.8   3.7 |   3.1  37.6  280  26 14   4.8   2.6
 12500   2.9  37.2  255  20 11   7.0   3.9 |   3.8  38.8  280  28 14   4.6   2.5
 12000   4.0  39.2  255  21 11   8.1   4.5 |   4.4  39.9  280  28 15   4.6   2.5
 11500   5.3  41.5  260  23 12   8.6   4.7 |   5.1  41.2  280  27 14   4.7   2.6
 11000   6.5  43.7  265  26 13   5.7   3.1 |   5.7  42.3  280  25 13   4.5   2.5
 10500   6.9  44.4  265  28 15   4.2   2.3 |   6.3  43.3  275  19 10   3.9   2.1
 10250   7.2  45.0  265  29 15   4.1   2.2 |   6.6  43.9  275  16  8   7.0   3.8
 10000   7.4  45.3  265  28 14   6.2   3.4 |   7.3  45.1  270  12  6  10.0   5.5
  9750   7.9  46.2  265  26 13   7.9   4.4 |   8.0  46.4  270  10  5   9.1   5.0
  9500   8.5  47.3  265  25 13   7.3   4.0 |   8.7  47.7  265   9  5   9.2   5.0
  9250   9.0  48.2  260  23 12   8.3   4.6 |   9.3  48.7  265   7  4   9.9   5.5
  9000   9.7  49.5  260  22 11   9.1   5.0 |  10.1  50.2  260   6  3  10.1   5.6
  8750  10.3  50.5  260  21 11   8.8   4.8 |  10.8  51.4  260   6  3   9.5   5.2
  8500  10.9  51.6  255  19 10   8.7   4.8 |  11.5  52.7  260   6  3   9.4   5.2
  8250  11.6  52.9  255  18  9   9.5   5.2 |  12.2  54.0  260   6  3  10.5   5.8
  8000  12.3  54.1  250  17  9   9.3   5.1 |  13.1  55.6  260   6  3  10.9   6.0
  7750  12.9  55.2  250  16  8   7.8   4.3 |  13.8  56.8  260   6  3   9.7   5.3
  7500  13.4  56.1  245  16  8   7.4   4.0 |  14.5  58.1  260   5  3   9.3   5.1
  7250  14.0  57.2  245  16  8   8.1   4.5 |  15.2  59.4  260   5  3  10.4   5.7
  7000  14.6  58.3  240  15  8   8.6   4.7 |  16.1  61.0  260   5  3  11.2   6.1
  6750  15.2  59.4  235  15  8   7.2   4.0 |  16.8  62.2  260   5  3   9.6   5.3
  6500  15.7  60.3  230  16  8   6.4   3.5 |  17.5  63.5  260   5  3   9.3   5.1
  6250  16.1  61.0  225  15  8   5.6   3.1 |  18.3  64.9  260   5  3  10.7   5.9
  6000  16.4  61.5  220  14  7   5.1   2.8 |  19.1  66.4  260   5  3  11.8   6.5
  5750  16.8  62.2  210  13  7   5.5   3.0 |  20.0  68.0  260   5  2  10.2   5.6
  5500  17.3  63.1  205  10  5  10.3   5.7 |  20.8  69.4  260   5  2  15.4   8.5

           09/15/2017 at 1500 MDT          |       09/15/2017 at 1800 MDT
                                           |
K index... +15.6  LI... +3.0               | K index... +23.6  LI... +0.7
CAPE... 0.0  CIN... 0.0                    | 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 -59.1 -74.4  225  31 16   3.1   1.7 | -58.9 -74.0  230  34 17   3.0   1.6
 45000 -54.9 -66.8  235  40 20   1.0   0.6 | -55.0 -67.0  235  39 20   0.5   0.3
 40000 -53.3 -63.9  240  55 28   1.8   1.0 | -54.3 -65.7  240  56 29   1.9   1.0
 38000 -51.0 -59.8  240  55 28   4.0   2.2 | -51.4 -60.5  240  56 29   4.9   2.7
 36000 -48.7 -55.7  245  55 28   4.0   2.2 | -48.4 -55.1  240  55 28   4.9   2.7
 34000 -45.3 -49.5  245  54 28   7.0   3.8 | -44.9 -48.8  240  55 28   6.7   3.7
 32000 -41.1 -42.0  245  52 27   7.0   3.8 | -40.9 -41.6  240  53 28   6.7   3.7
 30000 -35.9 -32.6  245  49 25   8.4   4.6 | -35.7 -32.3  240  51 26   8.5   4.7
 29000 -33.4 -28.1  240  47 24   8.4   4.6 | -33.2 -27.8  240  49 25   8.5   4.7
 28000 -30.9 -23.6  240  46 24   8.4   4.6 | -30.7 -23.3  240  48 25   8.5   4.7
 27000 -28.5 -19.3  240  45 23   7.9   4.4 | -28.2 -18.8  235  47 24   8.0   4.4
 26000 -26.1 -15.0  235  44 23   7.9   4.4 | -25.9 -14.6  235  46 24   7.9   4.4
 25000 -23.7 -10.7  235  43 22   7.9   4.3 | -23.5 -10.3  235  45 23   7.9   4.3
 24000 -21.4  -6.5  230  41 21   7.6   4.2 | -21.3  -6.3  235  43 22   6.1   3.3
 23000 -19.1  -2.4  225  39 20   7.7   4.2 | -19.5  -3.1  230  41 21   6.1   3.4
 22000 -16.8   1.8  215  37 19   7.8   4.3 | -17.7   0.1  230  40 20   6.2   3.4
 21000 -14.6   5.7  215  34 17   7.8   4.3 | -15.7   3.7  225  37 19   7.6   4.2
 20000 -12.2  10.0  225  29 15   7.8   4.3 | -13.4   7.9  230  33 17   7.7   4.2
 19500 -11.1  12.0  230  26 14   7.8   4.3 | -12.3   9.9  235  31 16   7.7   4.2
 19000  -9.9  14.2  240  25 13   7.8   4.3 | -11.2  11.8  235  29 15   7.6   4.2
 18500  -8.8  16.2  245  24 13   7.3   4.0 | -10.3  13.5  240  28 14   5.4   3.0
 18000  -7.7  18.1  245  25 13   7.3   4.0 |  -9.5  14.9  240  26 13   5.7   3.1
 17500  -6.7  19.9  245  25 13   7.0   3.8 |  -8.7  16.3  245  25 13   7.5   4.1
 17000  -5.7  21.7  250  24 12   6.8   3.7 |  -7.5  18.5  235  22 11   8.2   4.5
 16500  -4.7  23.5  255  23 12   6.8   3.7 |  -6.3  20.7  225  20 10   8.2   4.5
 16000  -3.3  26.1  255  22 11   6.6   3.6 |  -5.2  22.6  220  19 10   7.9   4.3
 15500  -2.3  27.9  255  21 11   6.6   3.6 |  -3.4  25.9  205  17  9   8.3   4.5
 15000  -1.4  29.5  255  20 10   6.6   3.6 |  -2.1  28.2  200  17  9   8.9   4.9
 14500  -0.4  31.3  260  19 10   6.5   3.6 |  -0.8  30.6  190  18  9   8.9   4.9
 14000   0.6  33.1  260  19 10   7.0   3.8 |   0.6  33.1  185  17  9   9.2   5.0
 13500   1.6  34.9  260  19 10   7.0   3.8 |   1.9  35.4  175  16  8   9.2   5.0
 13000   2.6  36.7  260  18  9   7.1   3.9 |   3.3  37.9  170  16  8   9.1   5.0
 12500   3.6  38.5  255  15  8   7.1   3.9 |   4.6  40.3  160  15  8   9.1   5.0
 12000   4.7  40.5  250  12  6   7.5   4.1 |   6.0  42.8  155  14  7   8.8   4.9
 11500   5.8  42.4  245   9  5   7.5   4.1 |   7.3  45.1  150  13  7   8.8   4.8
 11000   6.9  44.4  235   6  3   7.4   4.1 |   8.6  47.5  145  12  6   8.7   4.8
 10500   8.0  46.4  225   4  2   7.1   3.9 |   9.9  49.8  135  11  6   8.8   4.8
 10250   8.6  47.5  210   3  2  10.1   5.5 |  10.6  51.1  130  11  6  10.5   5.8
 10000   9.4  48.9  205   3  1  11.1   6.1 |  11.4  52.5  130  10  5  10.6   5.8
  9750  10.1  50.2  205   2  1   9.4   5.1 |  12.1  53.8  130  10  5   9.6   5.3
  9500  10.8  51.4  200   2  1   9.8   5.4 |  12.9  55.2  125  10  5   9.8   5.4
  9250  11.6  52.9  200   2  1   9.6   5.3 |  13.6  56.5  125   9  5   9.8   5.4
  9000  12.3  54.1  200   2  1   9.7   5.3 |  14.3  57.7  125   9  5   9.4   5.2
  8750  13.0  55.4  200   2  1   9.9   5.4 |  15.0  59.0  120   9  5   9.2   5.0
  8500  13.8  56.8  200   2  1   9.6   5.3 |  15.7  60.3  120   9  4   8.9   4.9
  8250  14.5  58.1  205   2  1  10.5   5.8 |  16.4  61.5  115   8  4  10.4   5.7
  8000  15.3  59.5  205   2  1  10.4   5.7 |  17.2  63.0  115   8  4  10.7   5.9
  7750  16.0  60.8  205   2  1   9.4   5.1 |  17.9  64.2  115   8  4   9.3   5.1
  7500  16.7  62.1  205   2  1   9.0   4.9 |  18.6  65.5  110   7  4   9.4   5.2
  7250  17.4  63.3  210   2  1  10.7   5.9 |  19.3  66.7  110   7  4   9.7   5.3
  7000  18.3  64.9  210   2  1  11.8   6.5 |  20.1  68.2  110   7  4   9.9   5.4
  6750  19.1  66.4  215   2  1   9.5   5.2 |  20.8  69.4  105   7  3   9.2   5.0
  6500  19.8  67.6  215   2  1   9.1   5.0 |  21.5  70.7  105   6  3   9.1   5.0
  6250  20.5  68.9  220   1  1  10.7   5.8 |  22.2  72.0  105   6  3  10.2   5.6
  6000  21.4  70.5  220   1  1  11.8   6.5 |  23.0  73.4  100   6  3  11.0   6.0
  5750  22.2  72.0  225   1  1  10.0   5.5 |  23.8  74.8  100   6  3  10.2   5.6
  5500  23.0  73.4  230   1  1  15.0   8.2 |  24.5  76.1  095   5  3  11.0   6.0
________________________________________________________________________________

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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