Soaring Guidance
Issued by NWS Pueblo, CO

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000
UXUS97 KPUB 231238
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0638 MDT Friday, September 23, 2016

This forecast is for Friday, September 23, 2016:

If the trigger temperature of 68.8 F/20.5 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 387 ft/min (2.0 m/s)
   Maximum height of thermals.................. 13532 ft MSL (6774 ft AGL)

Forecast maximum temperature................... 73.0 F/23.2 C
Time of trigger temperature.................... 1115 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 10074 ft MSL (3317 ft AGL)
Thermal soaring outlook for Saturday 09/24..... Good

Wave Soaring Index............................. Not available

Remarks...

Sunrise/Sunset.................... 06:48:06 / 18:55:04 MDT
Total possible sunshine........... 12 hr 6 min 58 sec (726 min 58 sec)
Altitude of sun at 12:51:05 MDT... 50.59 degrees

Upper air data from numerical model forecast valid on 09/23/2016 at 0600 MDT

Freezing level.................. 15313 ft MSL (8555 ft AGL)
Convective condensation level... 14140 ft MSL (7382 ft AGL)
Lifted condensation level....... 13618 ft MSL (6860 ft AGL)
Lifted index.................... -1.8
K index......................... +20.8

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -66.5 -87.7   205   49   25   1.5   0.8      M     M       M      M    M
 45000  -62.2 -80.0   200   52   27   6.8   3.7      M     M       M      M    M
 40000  -51.4 -60.5   180   43   22   7.1   3.9      M     M       M      M    M
 38000  -47.2 -53.0   190   48   25   7.1   3.9      M     M       M      M    M
 36000  -42.9 -45.2   200   54   28   7.1   3.9      M     M       M      M    M
 34000  -38.9 -38.0   205   59   30   6.4   3.5      M     M       M      M    M
 32000  -35.1 -31.2   200   62   32   6.5   3.6      M     M       M      M    M
 30000  -30.8 -23.4   205   61   32   7.5   4.1   39.8 103.7    13.2      M    M
 29000  -28.0 -18.4   205   59   31   7.5   4.1   38.8 101.8    12.5      M    M
 28000  -25.8 -14.4   205   58   30   7.4   4.1   38.1 100.5    12.1      M    M
 27000  -23.6 -10.5   205   57   29   7.2   4.0   37.0  98.7    11.4      M    M
 26000  -21.5  -6.7   205   56   29   7.2   4.0   36.1  96.9    10.7      M    M
 25000  -19.3  -2.7   200   54   28   7.3   4.0   35.2  95.4    10.1      M    M
 24000  -17.2   1.0   200   53   27   7.1   3.9   34.3  93.7     9.4      M    M
 23000  -15.0   5.0   200   51   26   7.1   3.9   33.3  91.9     8.7      M    M
 22000  -12.9   8.8   200   50   26   7.1   3.9   32.4  90.4     8.1      M    M
 21000  -10.8  12.6   200   48   25   6.9   3.8   31.5  88.6     7.3      M    M
 20000   -8.8  16.2   200   47   24   6.9   3.8   30.5  86.8     6.5      M    M
 19500   -7.7  18.1   200   46   24   6.9   3.8   30.0  86.0     6.1      M    M
 19000   -6.7  19.9   200   45   23   6.4   3.5   29.6  85.3     5.8      M    M
 18500   -5.9  21.4   200   45   23   5.8   3.2   28.9  84.0     5.2      M    M
 18000   -5.1  22.8   200   44   22   5.8   3.2   28.2  82.8     4.6      M    M
 17500   -4.2  24.4   200   43   22   6.0   3.3   27.6  81.7     3.9      M    M
 17000   -3.4  25.9   200   42   21   6.1   3.4   27.0  80.6     3.3      M    M
 16500   -2.6  27.3   200   41   21   6.5   3.6   26.4  79.5     2.7      M    M
 16000   -1.6  29.1   200   40   20   7.0   3.8   25.9  78.6     2.2      M    M
 15500   -0.6  30.9   200   39   20   7.0   3.8   25.5  77.8     1.8      M    M
 15000    0.4  32.7   200   37   19   6.7   3.7   25.0  77.0     1.3      M    M
 14500    1.8  35.2   200   33   17   7.0   3.8   24.2  75.6     0.5      M    M
 14000    2.9  37.2   200   32   17   7.9   4.3   23.9  75.0     0.2      M    M
 13500    4.1  39.4   205   32   16   7.8   4.3   23.6  74.5    -0.1    573  2.9
 13000    5.2  41.4   210   32   16   7.5   4.1   23.3  73.9    -0.4    524  2.7
 12500    6.4  43.5   210   32   16   7.5   4.1   22.9  73.3    -0.7    476  2.4
 12000    7.4  45.3   215   34   18   7.2   3.9   22.5  72.5    -1.1    429  2.2
 11750    7.9  46.2   215   34   18   7.2   3.9   22.3  72.2    -1.4    407  2.1
 11500    8.4  47.1   215   34   18   7.2   4.0   22.1  71.8    -1.6    384  1.9
 11250    9.0  48.2   220   34   18   7.2   3.9   21.9  71.5    -1.8    361  1.8
 11000    9.5  49.1   220   35   18   6.8   3.7   21.7  71.1    -2.0    338  1.7
 10750    9.9  49.8   220   34   17   6.5   3.6   21.5  70.6    -2.3    317  1.6
 10500   10.4  50.7   220   32   17   6.8   3.7   21.2  70.2    -2.6    296  1.5
 10250   10.8  51.4   220   31   16   6.0   3.3   21.0  69.8    -2.8    274  1.4
 10000   11.2  52.2   220   30   16   6.1   3.4   20.7  69.2    -3.2    255  1.3
  9750   11.7  53.1   220   30   15   7.0   3.9   20.5  68.8    -3.5    234  1.2
  9500   12.2  54.0   220   29   15   6.9   3.8   20.2  68.4    -3.7    213  1.1
  9250   12.6  54.7   220   28   15   6.7   3.7   20.0  68.0    -4.0    192  1.0
  9000   13.0  55.4   220   28   14   6.4   3.5   19.8  67.6    -4.3    172  0.9
  8750   13.5  56.3   220   26   14   6.6   3.6   19.5  67.1    -4.6    151  0.8
  8500   13.9  57.0   220   25   13   8.0   4.4   19.3  66.8    -4.9    130  0.7
  8250   14.4  57.9   215   24   12   3.7   2.0   19.1  66.4    -5.2    109  0.6
  8000   14.3  57.7   215   22   11  -2.1  -1.2   18.4  65.1    -6.0    103  0.5
  7750   14.3  57.7   210   19   10   2.6   1.4   17.6  63.7    -6.8     98  0.5
  7500   14.6  58.3   205   15    8   5.1   2.8   17.2  63.0    -7.2     80  0.4
  7250   14.5  58.1   200   12    6  -9.8  -5.4   16.6  61.9    -7.9     75  0.4
  7000   13.1  55.6   195    9    4 -28.7 -15.7   14.9  58.8    -9.5    112  0.6
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           09/23/2016 at 0900 MDT          |       09/23/2016 at 1200 MDT
                                           |
K index... +8.9  LI... +272.5              | K index... -16.5  LI... +272.1
CAPE... +166.0  CIN... -49.4               | CAPE... +193.3  CIN... -13.5
                                           |
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 -66.0 -86.8  200  40 20   0.8   0.4 | -65.3 -85.5  200  49 25   2.0   1.1
 45000 -61.9 -79.4  190  60 31   7.6   4.2 | -60.2 -76.4  195  70 36   7.0   3.8
 40000 -50.6 -59.1  190  70 36   6.0   3.3 | -49.9 -57.8  185  80 41   4.6   2.5
 38000 -46.9 -52.4  195  71 36   6.1   3.4 | -47.0 -52.6  190  80 41   4.8   2.6
 36000 -43.2 -45.8  200  71 37   6.1   3.4 | -44.1 -47.4  195  82 42   4.8   2.7
 34000 -39.6 -39.3  200  71 37   6.0   3.3 | -40.4 -40.7  200  81 42   6.8   3.7
 32000 -36.0 -32.8  200  71 36   6.0   3.3 | -36.3 -33.3  200  78 40   6.8   3.7
 30000 -31.3 -24.3  200  64 33   7.4   4.1 | -31.6 -24.9  200  73 37   6.9   3.8
 29000 -29.0 -20.2  200  60 31   7.4   4.1 | -29.6 -21.3  205  70 36   6.9   3.8
 28000 -26.8 -16.2  200  56 29   7.5   4.1 | -27.5 -17.5  205  67 34   6.9   3.8
 27000 -24.5 -12.1  200  55 28   7.8   4.3 | -25.2 -13.4  205  65 33   8.0   4.4
 26000 -22.2  -8.0  200  54 28   7.8   4.3 | -22.8  -9.0  205  63 32   8.0   4.4
 25000 -19.8  -3.6  200  54 28   7.8   4.3 | -20.4  -4.7  205  60 31   8.0   4.4
 24000 -17.6   0.3  200  53 27   7.3   4.0 | -18.1  -0.6  205  58 30   7.7   4.2
 23000 -15.4   4.3  200  52 27   7.3   4.0 | -15.8   3.6  200  55 28   7.7   4.2
 22000 -13.3   8.1  200  52 27   7.3   4.0 | -13.5   7.7  200  52 27   7.7   4.2
 21000 -11.2  11.8  200  51 26   6.6   3.6 | -11.5  11.3  195  52 27   6.0   3.3
 20000  -9.3  15.3  195  50 26   6.6   3.6 |  -9.7  14.5  195  54 28   6.0   3.3
 19500  -8.3  17.1  195  49 25   6.6   3.6 |  -8.8  16.2  195  55 28   6.0   3.3
 19000  -7.3  18.9  195  49 25   6.2   3.4 |  -7.9  17.8  195  56 29   6.1   3.4
 18500  -6.5  20.3  195  49 25   5.3   2.9 |  -6.9  19.6  195  56 29   6.7   3.6
 18000  -5.8  21.6  195  50 26   5.3   2.9 |  -5.9  21.4  195  56 29   6.6   3.6
 17500  -5.0  23.0  190  51 26   6.2   3.4 |  -4.9  23.2  195  56 29   7.0   3.9
 17000  -4.0  24.8  195  50 26   6.3   3.4 |  -3.8  25.2  195  55 28   7.1   3.9
 16500  -3.1  26.4  195  49 25   6.3   3.5 |  -2.8  27.0  195  54 28   7.2   3.9
 16000  -2.2  28.0  195  48 25   6.3   3.5 |  -1.7  28.9  195  54 28   7.2   3.9
 15500  -1.3  29.7  195  48 25   6.3   3.4 |  -0.6  30.9  195  53 27   7.3   4.0
 15000   0.2  32.4  195  46 24   7.5   4.1 |   0.9  33.6  195  52 27   6.5   3.6
 14500   1.3  34.3  195  45 23   7.6   4.1 |   1.8  35.2  195  51 26   6.5   3.5
 14000   2.4  36.3  195  45 23   7.5   4.1 |   2.7  36.9  200  49 25   5.5   3.0
 13500   3.5  38.3  200  44 23   7.6   4.2 |   3.5  38.3  200  48 25   5.7   3.1
 13000   4.6  40.3  200  44 23   6.6   3.6 |   4.2  39.6  200  46 24   5.4   3.0
 12500   5.5  41.9  205  44 23   6.8   3.7 |   5.0  41.0  200  45 23   5.4   3.0
 12000   6.4  43.5  205  43 22   6.2   3.4 |   5.7  42.3  200  41 21   6.2   3.4
 11750   6.9  44.4  205  42 22   6.2   3.4 |   6.1  43.0  200  40 20   6.5   3.5
 11500   7.3  45.1  210  41 21   6.2   3.4 |   6.5  43.7  200  38 20   6.2   3.4
 11250   7.7  45.9  210  40 21   6.6   3.6 |   6.9  44.4  200  37 19   7.9   4.3
 11000   8.1  46.6  210  38 20   6.7   3.7 |   7.4  45.3  200  35 18   8.8   4.8
 10750   8.5  47.3  210  37 19   6.4   3.5 |   7.9  46.2  200  33 17   7.7   4.2
 10500   9.0  48.2  210  35 18   6.7   3.7 |   8.4  47.1  195  31 16   8.6   4.7
 10250   9.4  48.9  210  33 17   6.0   3.3 |   8.9  48.0  195  29 15   6.5   3.6
 10000   9.7  49.5  210  32 16   6.3   3.4 |   9.2  48.6  190  27 14   7.7   4.3
  9750  10.2  50.4  210  30 15   7.3   4.0 |  10.0  50.0  190  26 13  10.7   5.9
  9500  10.7  51.3  205  28 15   7.2   3.9 |  10.7  51.3  185  25 13  10.0   5.5
  9250  11.1  52.0  205  27 14   6.9   3.8 |  11.4  52.5  185  24 13   9.9   5.4
  9000  11.5  52.7  205  25 13   6.5   3.6 |  12.1  53.8  180  24 12   9.4   5.2
  8750  12.0  53.6  200  24 12   7.1   3.9 |  12.8  55.0  180  24 12  10.3   5.7
  8500  12.5  54.5  200  22 12   7.6   4.2 |  13.6  56.5  180  23 12  10.8   5.9
  8250  13.1  55.6  195  21 11   7.0   3.8 |  14.4  57.9  180  23 12  10.7   5.9
  8000  13.5  56.3  190  19 10   6.2   3.4 |  15.2  59.4  180  23 12  11.2   6.1
  7750  14.0  57.2  190  17  9   7.2   4.0 |  16.0  60.8  180  22 12  10.2   5.6
  7500  14.5  58.1  185  14  7   8.1   4.4 |  16.7  62.1  180  22 11   8.7   4.8
  7250  15.1  59.2  180  12  6   7.2   4.0 |  17.4  63.3  180  21 11  12.5   6.8
  7000  15.6  60.1  175  11  6   6.5   3.6 |  18.6  65.5  180  20 10  18.6  10.2
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           09/23/2016 at 1500 MDT          |       09/23/2016 at 1800 MDT
                                           |
K index... +3.0  LI... +274.5              | K index... +22.4  LI... +271.9
CAPE... 0.0  CIN... -0.4                   | CAPE... +54.0  CIN... -12.4
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -63.0 -81.4  200  55 28   1.4   0.8 | -61.4 -78.5  210  48 25   1.4   0.8
 45000 -59.2 -74.6  195  81 41   5.7   3.1 | -58.2 -72.8  200  77 40   4.3   2.4
 40000 -50.8 -59.4  185  89 46   4.8   2.6 | -51.7 -61.1  185  94 48   4.6   2.5
 38000 -47.9 -54.2  190  86 44   4.8   2.6 | -48.9 -56.0  190  89 46   4.7   2.6
 36000 -45.0 -49.0  195  84 43   4.8   2.6 | -46.1 -51.0  195  85 44   4.6   2.5
 34000 -41.4 -42.5  200  81 42   6.7   3.7 | -42.5 -44.5  195  80 41   6.9   3.8
 32000 -37.3 -35.1  200  76 39   6.7   3.7 | -38.4 -37.1  195  76 39   6.9   3.8
 30000 -32.4 -26.3  210  74 38   7.8   4.3 | -33.3 -27.9  200  71 37   8.0   4.4
 29000 -30.0 -22.0  210  74 38   7.9   4.3 | -30.9 -23.6  200  70 36   8.0   4.4
 28000 -27.7 -17.9  215  74 38   7.9   4.3 | -28.5 -19.3  205  68 35   8.0   4.4
 27000 -25.3 -13.5  210  71 37   7.8   4.3 | -26.2 -15.2  205  66 34   7.9   4.3
 26000 -23.0  -9.4  210  68 35   7.8   4.3 | -23.8 -10.8  200  64 33   7.9   4.3
 25000 -20.7  -5.3  205  64 33   7.8   4.3 | -21.5  -6.7  200  61 32   7.9   4.3
 24000 -18.5  -1.3  200  61 31   6.9   3.8 | -19.2  -2.6  200  60 31   7.5   4.1
 23000 -16.3   2.7  195  58 30   6.9   3.8 | -16.9   1.6  200  59 30   7.5   4.1
 22000 -14.2   6.4  190  56 29   7.0   3.8 | -14.7   5.5  200  58 30   7.4   4.1
 21000 -12.3   9.9  190  55 28   6.0   3.3 | -13.0   8.6  200  56 29   4.0   2.2
 20000 -10.5  13.1  200  55 28   6.0   3.3 | -11.9  10.6  200  54 28   4.0   2.2
 19500  -9.6  14.7  200  55 28   6.0   3.3 | -11.3  11.7  200  52 27   4.0   2.2
 19000  -8.7  16.3  205  56 29   5.9   3.3 | -10.8  12.6  200  51 26   4.2   2.3
 18500  -7.9  17.8  205  55 28   5.7   3.1 | -10.0  14.0  195  49 25   5.8   3.2
 18000  -7.0  19.4  210  54 28   5.8   3.2 |  -9.2  15.4  195  47 24   5.7   3.1
 17500  -6.2  20.8  210  53 27   5.3   2.9 |  -8.3  17.1  190  44 23   6.9   3.8
 17000  -5.4  22.3  210  51 26   5.3   2.9 |  -7.2  19.0  190  42 22   7.4   4.1
 16500  -4.7  23.5  210  50 26   5.5   3.0 |  -6.2  20.8  185  40 21   7.5   4.1
 16000  -3.9  25.0  210  47 24   5.8   3.2 |  -5.0  23.0  185  38 20   8.0   4.4
 15500  -3.1  26.4  205  45 23   6.0   3.3 |  -3.9  25.0  185  36 19   7.9   4.4
 15000  -1.7  28.9  200  41 21   7.9   4.3 |  -2.7  27.1  185  34 18   8.3   4.5
 14500  -0.6  30.9  195  39 20   8.1   4.4 |  -0.9  30.4  185  30 15   8.4   4.6
 14000   0.6  33.1  190  37 19   9.2   5.0 |   0.3  32.5  190  28 14   8.9   4.9
 13500   1.9  35.4  190  36 18   9.1   5.0 |   1.6  34.9  190  26 13   8.9   4.9
 13000   3.3  37.9  185  35 18   9.9   5.4 |   2.9  37.2  195  24 12   9.1   5.0
 12500   4.8  40.6  185  34 18   9.4   5.2 |   4.2  39.6  200  23 12   9.1   5.0
 12000   6.2  43.2  185  33 17   9.6   5.3 |   5.5  41.9  205  23 12   8.2   4.5
 11750   6.9  44.4  185  33 17   9.7   5.3 |   6.1  43.0  210  23 12   8.2   4.5
 11500   7.6  45.7  185  33 17   9.6   5.3 |   6.6  43.9  215  23 12   7.8   4.3
 11250   8.3  46.9  185  33 17  10.0   5.5 |   7.2  45.0  215  23 12   9.3   5.1
 11000   9.1  48.4  185  33 17  10.2   5.6 |   8.0  46.4  215  23 12  10.0   5.5
 10750   9.8  49.6  185  33 17   9.8   5.4 |   8.7  47.7  220  24 12   8.9   4.9
 10500  10.6  51.1  185  33 17  10.0   5.5 |   9.4  48.9  220  24 12   9.4   5.2
 10250  11.3  52.3  185  32 17   9.6   5.3 |  10.0  50.0  220  25 13   8.2   4.5
 10000  12.0  53.6  185  32 17   9.7   5.3 |  10.6  51.1  220  25 13   8.8   4.8
  9750  12.8  55.0  185  32 17  10.0   5.5 |  11.4  52.5  220  25 13  10.3   5.6
  9500  13.5  56.3  185  32 16   9.9   5.4 |  12.1  53.8  220  25 13   9.9   5.5
  9250  14.2  57.6  185  32 16  10.0   5.5 |  12.9  55.2  220  25 13   9.8   5.4
  9000  15.0  59.0  185  31 16  10.0   5.5 |  13.6  56.5  220  25 13   9.5   5.2
  8750  15.7  60.3  185  31 16  10.1   5.6 |  14.3  57.7  220  25 13   9.9   5.4
  8500  16.5  61.7  185  31 16  10.1   5.5 |  15.0  59.0  220  25 13  10.1   5.6
  8250  17.2  63.0  185  31 16  10.5   5.7 |  15.8  60.4  220  25 13  10.0   5.5
  8000  18.1  64.6  185  30 15  11.5   6.3 |  16.5  61.7  220  25 13  10.2   5.6
  7750  18.9  66.0  185  29 15  10.5   5.7 |  17.3  63.1  215  24 12   9.2   5.0
  7500  19.6  67.3  180  28 14   8.4   4.6 |  17.9  64.2  215  23 12   8.6   4.7
  7250  20.2  68.4  180  26 14  11.0   6.0 |  18.5  65.3  215  21 11   6.9   3.8
  7000  21.3  70.3  180  25 13  16.0   8.8 |  18.8  65.8  215  19 10   2.5   1.4
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

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 Air Force Academy
in Colorado Springs, Colorado at

                   North Latitude:  38 deg 58 min 48.000 sec
                   West Longitude: 104 deg 49 min 12.000 sec
                   Elevation: 6572 feet (2003 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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