Soaring Guidance
Issued by NWS Pueblo, CO

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000
UXUS97 KPUB 171032
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0432 MDT Friday, April 17, 2015

This forecast is for Friday, April 17, 2015:

If the trigger temperature of 43.7 F/6.5 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 8281 ft MSL (1523 ft AGL)

Forecast maximum temperature................... 36.0 F/2.7 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
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................. 6818 ft MSL (61 ft AGL)
Thermal soaring outlook for Saturday 04/18..... Poor

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

Remarks...

Sunrise/Sunset.................... 06:19:56 / 19:36:59 MDT
Total possible sunshine........... 13 hr 17 min 2 sec (797 min 2 sec)
Altitude of sun at 12:58:37 MDT... 61.61 degrees

Upper air data from numerical model forecast valid on 04/17/2015 at 0600 MDT

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 10397 ft MSL (3639 ft AGL)
Lifted condensation level....... 8477 ft MSL (1719 ft AGL)
Lifted index.................... +3.6
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  -56.2 -69.2   215   15    8   4.0   2.2      M     M       M      M    M
 45000  -50.4 -58.7   210   17    9   1.3   0.7      M     M       M      M    M
 40000  -48.4 -55.1   195   37   19   1.4   0.7      M     M       M      M    M
 38000  -47.8 -54.0   185   42   22   0.3   0.1      M     M       M      M    M
 36000  -47.7 -53.9   165   46   23   0.3   0.1      M     M       M      M    M
 34000  -47.5 -53.5   155   53   27   1.1   0.6      M     M       M      M    M
 32000  -46.2 -51.2   150   51   26   2.0   1.1      M     M       M      M    M
 30000  -44.8 -48.6   145   50   26   4.3   2.4   25.8  78.5    18.0      M    M
 29000  -43.6 -46.5   150   50   26   4.2   2.3   23.5  74.3    16.5      M    M
 28000  -42.3 -44.1   150   50   26   4.2   2.3   21.3  70.4    15.0      M    M
 27000  -41.1 -42.0   150   50   26   3.8   2.1   19.4  66.8    13.6      M    M
 26000  -39.9 -39.8   155   51   26   7.9   4.4   18.3  64.9    12.9      M    M
 25000  -36.6 -33.9   155   51   26   7.9   4.3   17.5  63.6    12.5      M    M
 24000  -34.2 -29.6   160   52   27   7.9   4.3   16.9  62.5    12.1      M    M
 23000  -31.8 -25.2   160   52   27   8.1   4.4   16.3  61.3    11.7      M    M
 22000  -29.4 -20.9   165   53   27   8.1   4.5   15.7  60.2    11.3      M    M
 21000  -26.9 -16.4   165   53   27   8.0   4.4   15.2  59.3    11.0      M    M
 20000  -24.6 -12.3   165   52   27   7.7   4.2   14.4  57.9    10.5      M    M
 19500  -23.5 -10.3   165   51   26   7.7   4.2   14.0  57.3    10.2      M    M
 19000  -22.4  -8.3   165   50   26   7.7   4.2   13.7  56.7    10.0      M    M
 18500  -21.2  -6.2   170   50   26   7.6   4.2   13.4  56.1     9.7      M    M
 18000  -20.1  -4.2   170   48   25   7.0   3.9   13.0  55.4     9.4      M    M
 17500  -19.1  -2.4   170   46   24   7.1   3.9   12.5  54.5     9.1      M    M
 17000  -18.0  -0.4   170   43   22   6.8   3.8   12.1  53.7     8.7      M    M
 16500  -17.0   1.4   165   38   20   6.8   3.7   11.6  52.8     8.3      M    M
 16000  -16.0   3.2   165   34   18   6.8   3.7   11.1  52.0     7.9      M    M
 15500  -14.5   5.9   155   29   15   6.6   3.6   10.3  50.6     7.2      M    M
 15000  -13.5   7.7   145   27   14   8.3   4.5    9.9  49.8     6.9      M    M
 14500  -12.2  10.0   140   26   14   8.7   4.8    9.7  49.5     6.7      M    M
 14000  -10.9  12.4   135   26   14   9.1   5.0    9.6  49.2     6.6      M    M
 13500   -9.5  14.9   135   27   14   9.3   5.1    9.5  49.1     6.5      M    M
 13000   -8.2  17.2   130   27   14   9.2   5.1    9.4  49.0     6.5      M    M
 12500   -6.9  19.6   130   27   14   9.1   5.0    9.3  48.8     6.3      M    M
 12000   -5.7  21.7   130   28   14   6.4   3.5    9.2  48.5     6.1      M    M
 11750   -5.4  22.3   130   27   14   3.6   2.0    8.8  47.8     5.7      M    M
 11500   -5.1  22.8   130   26   14   4.0   2.2    8.3  46.9     5.2      M    M
 11250   -4.9  23.2   130   26   13   3.6   2.0    7.8  46.1     4.8      M    M
 11000   -4.6  23.7   130   25   13   5.3   2.9    7.4  45.3     4.3      M    M
 10750   -4.1  24.6   125   23   12   6.2   3.4    7.1  44.8     4.0      M    M
 10500   -3.7  25.3   120   22   11   5.3   2.9    6.8  44.2     3.7      M    M
 10250   -3.3  26.1   120   21   11   5.4   3.0    6.4  43.6     3.4      M    M
 10000   -3.0  26.6   115   20   10   6.0   3.3    6.1  43.0     3.1      M    M
  9750   -2.5  27.5   110   19   10   8.0   4.4    5.9  42.6     2.8      M    M
  9500   -1.8  28.8   100   18    9   9.1   5.0    5.8  42.5     2.7      M    M
  9250   -1.2  29.8   095   18    9   7.9   4.3    5.7  42.3     2.6      M    M
  9000   -0.7  30.7   090   18    9   5.6   3.1    5.5  41.9     2.4      M    M
  8750   -0.5  31.1   080   18    9  -1.1  -0.6    5.0  41.0     1.9      M    M
  8500   -0.8  30.6   065   18    9  -5.8  -3.2    3.9  39.0     0.9      M    M
  8250   -1.1  30.0   050   18    9  -3.5  -1.9    2.8  37.0    -0.2    154  0.8
  8000   -1.3  29.7   035   18    9  -3.5  -1.9    1.8  35.3    -1.1    153  0.8
  7750   -1.5  29.3   020   17    9   0.1   0.1    0.9  33.6    -2.0    151  0.8
  7500   -1.3  29.7   010   16    8   4.9   2.7    0.4  32.7    -2.5    136  0.7
  7250   -1.0  30.2   360   14    7   2.8   1.5    0.1  32.2    -2.8    120  0.6
  7000   -0.9  30.4   360   13    7   0.0   0.0    0.0  32.1    -2.9    110  0.6
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           04/17/2015 at 0900 MDT          |       04/17/2015 at 1200 MDT
                                           |
K index... +13.5  LI... +270.3             | K index... -4.5  LI... +272.1
CAPE... +404.4  CIN... -1.2                | CAPE... +187.3  CIN... -2.7
                                           |
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 -55.9 -68.6  220  19 10   3.7   2.0 | -55.4 -67.7  210  16  8   3.2   1.8
 45000 -50.5 -58.9  195  20 10   1.8   1.0 | -50.6 -59.1  175  22 11   1.5   0.8
 40000 -47.6 -53.7  190  35 18   1.9   1.0 | -48.4 -55.1  185  31 16   1.5   0.8
 38000 -46.7 -52.1  180  38 20   1.0   0.6 | -47.0 -52.6  180  34 17   3.1   1.7
 36000 -46.1 -51.0  170  39 20   1.1   0.6 | -45.2 -49.4  175  34 18   3.1   1.7
 34000 -45.4 -49.7  155  42 22   1.5   0.8 | -43.2 -45.8  165  35 18   1.8   1.0
 32000 -44.0 -47.2  145  42 21   2.2   1.2 | -42.1 -43.8  155  37 19   1.8   1.0
 30000 -42.6 -44.7  140  43 22   2.7   1.5 | -40.9 -41.6  145  39 20   2.5   1.4
 29000 -41.8 -43.2  140  44 23   2.8   1.5 | -40.1 -40.2  150  41 21   2.6   1.4
 28000 -41.0 -41.8  140  46 24   2.8   1.5 | -39.3 -38.7  150  43 22   2.6   1.4
 27000 -40.1 -40.2  145  48 25   2.5   1.4 | -38.6 -37.5  155  45 23   2.6   1.4
 26000 -38.7 -37.7  145  49 25   5.5   3.0 | -37.9 -36.2  155  46 24   2.2   1.2
 25000 -37.1 -34.8  145  51 26   5.6   3.0 | -37.2 -35.0  155  47 24   2.2   1.2
 24000 -35.4 -31.7  150  52 27   5.5   3.0 | -36.5 -33.7  150  48 25   2.2   1.2
 23000 -33.4 -28.1  150  52 27   7.6   4.1 | -35.0 -31.0  150  49 25   7.6   4.1
 22000 -31.1 -24.0  150  52 27   7.6   4.2 | -32.7 -26.9  150  48 25   7.7   4.2
 21000 -28.8 -19.8  150  52 27   7.6   4.2 | -30.4 -22.7  150  48 25   7.7   4.2
 20000 -26.4 -15.5  150  50 26   8.0   4.4 | -27.8 -18.0  150  48 24   8.8   4.8
 19500 -25.2 -13.4  150  49 25   8.0   4.4 | -26.5 -15.7  150  47 24   8.8   4.8
 19000 -24.0 -11.2  150  48 24   8.0   4.4 | -25.1 -13.2  155  47 24   8.8   4.8
 18500 -22.8  -9.0  150  46 24   8.0   4.4 | -23.8 -10.8  155  47 24   8.9   4.9
 18000 -21.7  -7.1  150  45 23   7.3   4.0 | -22.6  -8.7  155  46 23   7.1   3.9
 17500 -20.6  -5.1  150  43 22   7.3   4.0 | -21.5  -6.7  155  43 22   7.3   4.0
 17000 -19.5  -3.1  150  41 21   7.7   4.2 | -20.4  -4.7  150  41 21   7.4   4.1
 16500 -18.4  -1.1  145  39 20   7.8   4.3 | -19.3  -2.7  145  39 20   7.5   4.1
 16000 -16.6   2.1  135  37 19   8.6   4.7 | -17.5   0.5  140  37 19   8.2   4.5
 15500 -15.3   4.5  135  36 19   8.6   4.7 | -16.3   2.7  135  37 19   8.3   4.5
 15000 -14.1   6.6  130  36 19   8.8   4.8 | -15.1   4.8  135  38 20   8.4   4.6
 14500 -12.8   9.0  130  36 19   8.9   4.9 | -13.8   7.2  135  39 20   8.5   4.6
 14000 -11.5  11.3  130  37 19   8.3   4.6 | -12.5   9.5  135  40 21   8.0   4.4
 13500 -10.4  13.3  130  36 18   7.9   4.3 | -11.4  11.5  140  38 20   7.5   4.1
 13000  -9.2  15.4  130  35 18   7.9   4.3 | -10.3  13.5  145  37 19   7.1   3.9
 12500  -8.2  17.2  135  34 17   7.8   4.3 |  -9.4  15.1  145  34 17   6.8   3.7
 12000  -7.1  19.2  135  32 16   7.7   4.2 |  -8.7  16.3  145  29 15   3.9   2.1
 11750  -6.5  20.3  135  31 16   8.3   4.6 |  -8.3  17.1  145  27 14   5.7   3.1
 11500  -5.9  21.4  135  31 16   8.3   4.6 |  -7.9  17.8  145  24 13   6.1   3.4
 11250  -5.3  22.5  140  30 15   8.3   4.6 |  -7.5  18.5  145  22 11   5.6   3.1
 11000  -4.7  23.5  140  29 15   9.0   4.9 |  -7.2  19.0  145  20 10   7.9   4.4
 10750  -4.0  24.8  135  29 15   8.7   4.8 |  -6.5  20.3  140  18  9   8.4   4.6
 10500  -3.5  25.7  135  28 15   7.8   4.3 |  -6.0  21.2  145  16  8   6.6   3.6
 10250  -2.9  26.8  130  28 14   8.4   4.6 |  -5.5  22.1  145  14  7   6.9   3.8
 10000  -2.3  27.9  130  28 14   6.7   3.7 |  -5.0  23.0  145  13  7   8.0   4.4
  9750  -1.9  28.6  125  27 14   5.6   3.1 |  -4.4  24.1  145  12  6   9.5   5.2
  9500  -1.4  29.5  120  25 13   6.6   3.6 |  -3.7  25.3  140  11  5   9.7   5.3
  9250  -1.0  30.2  115  24 12   5.7   3.1 |  -3.0  26.6  140  10  5   9.4   5.1
  9000  -0.6  30.9  105  23 12   3.8   2.1 |  -2.4  27.7  135   9  5   8.5   4.7
  8750  -0.5  31.1  095  22 11  -1.3  -0.7 |  -1.8  28.8  130   9  5   7.0   3.8
  8500  -0.8  30.6  085  19 10  -4.5  -2.5 |  -1.4  29.5  120   9  4   6.8   3.7
  8250  -1.0  30.2  065  18  9  -2.9  -1.6 |  -0.9  30.4  110   8  4   5.3   2.9
  8000  -1.2  29.8  050  17  9  -2.8  -1.5 |  -0.6  30.9  095   7  3   3.0   1.6
  7750  -1.3  29.7  035  16  8   0.2   0.1 |  -0.4  31.3  075   5  3   3.0   1.6
  7500  -1.1  30.0  025  14  7   4.3   2.4 |  -0.2  31.6  045   4  2   2.8   1.5
  7250  -0.8  30.6  015  13  6   3.5   1.9 |   0.0  32.0  010   4  2   2.9   1.6
  7000  -0.6  30.9  010  11  6   2.2   1.2 |   0.3  32.5  360   4  2   3.0   1.7
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/17/2015 at 1500 MDT          |       04/17/2015 at 1800 MDT
                                           |
K index... +3.9  LI... +271.7              | K index... +9.5  LI... +271.6
CAPE... +183.4  CIN... -23.2               | CAPE... +185.0  CIN... -39.1
                                           |
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 -55.4 -67.7  205  16  8   3.2   1.8 | -55.4 -67.7  220  19 10   4.0   2.2
 45000 -50.7 -59.3  175  28 14   2.1   1.1 | -49.6 -57.3  205  24 12   2.0   1.1
 40000 -47.7 -53.9  190  27 14   1.9   1.0 | -47.2 -53.0  190  27 14   1.5   0.8
 38000 -46.1 -51.0  185  27 14   3.4   1.9 | -45.9 -50.6  185  28 14   2.6   1.4
 36000 -44.1 -47.4  175  28 14   3.4   1.9 | -44.4 -47.9  170  29 15   2.6   1.4
 34000 -42.1 -43.8  170  29 15   2.2   1.2 | -42.9 -45.2  160  31 16   1.7   1.0
 32000 -41.1 -42.0  170  31 16   1.7   0.9 | -42.1 -43.8  165  29 15   1.3   0.7
 30000 -40.0 -40.0  170  33 17   1.6   0.9 | -41.3 -42.3  165  27 14   1.5   0.8
 29000 -39.6 -39.3  170  34 18   1.4   0.8 | -40.8 -41.4  160  29 15   1.8   1.0
 28000 -39.2 -38.6  165  36 18   1.4   0.8 | -40.3 -40.5  155  32 16   1.8   1.0
 27000 -38.7 -37.7  165  38 19   1.4   0.8 | -39.6 -39.3  150  35 18   1.8   1.0
 26000 -38.3 -36.9  160  39 20   1.3   0.7 | -39.0 -38.2  145  36 19   2.0   1.1
 25000 -37.9 -36.2  160  41 21   1.3   0.7 | -38.4 -37.1  140  37 19   2.0   1.1
 24000 -37.5 -35.5  155  42 22   1.1   0.6 | -37.9 -36.2  140  39 20   1.7   0.9
 23000 -35.9 -32.6  155  43 22   8.4   4.6 | -36.1 -33.0  140  38 20   8.3   4.6
 22000 -33.3 -27.9  155  43 22   8.5   4.7 | -33.6 -28.5  145  37 19   8.4   4.6
 21000 -30.8 -23.4  155  42 22   8.4   4.6 | -31.0 -23.8  150  36 19   8.5   4.7
 20000 -28.4 -19.1  160  41 21   8.0   4.4 | -28.4 -19.1  155  36 18   8.9   4.9
 19500 -27.2 -17.0  160  40 20   8.0   4.4 | -27.1 -16.8  160  36 18   8.9   4.9
 19000 -26.0 -14.8  160  39 20   8.0   4.4 | -25.8 -14.4  160  36 18   8.9   4.9
 18500 -24.8 -12.6  160  38 19   8.0   4.4 | -24.5 -12.1  165  36 18   8.9   4.9
 18000 -23.6 -10.5  160  36 19   7.6   4.2 | -23.1  -9.6  165  35 18   9.0   4.9
 17500 -22.5  -8.5  160  35 18   7.6   4.2 | -21.8  -7.2  165  35 18   9.0   4.9
 17000 -21.4  -6.5  160  34 17   7.7   4.2 | -20.5  -4.9  170  34 18   9.0   4.9
 16500 -20.2  -4.4  160  33 17   7.8   4.3 | -19.1  -2.4  170  33 17   8.9   4.9
 16000 -19.1  -2.4  155  32 16   8.0   4.4 | -17.8  -0.0  170  32 17   8.6   4.7
 15500 -17.8  -0.0  155  31 16   8.2   4.5 | -16.6   2.1  175  31 16   8.3   4.6
 15000 -16.6   2.1  160  31 16   8.2   4.5 | -15.3   4.5  175  30 15   8.3   4.5
 14500 -15.4   4.3  160  30 15   8.4   4.6 | -14.1   6.6  180  28 15   8.1   4.4
 14000 -13.5   7.7  160  27 14   8.4   4.6 | -12.3   9.9  180  26 14   8.2   4.5
 13500 -12.3   9.9  160  25 13   8.4   4.6 | -11.1  12.0  185  25 13   8.3   4.5
 13000 -11.0  12.2  165  24 12   8.9   4.9 |  -9.9  14.2  185  24 12   8.1   4.5
 12500  -9.6  14.7  165  22 12   9.7   5.3 |  -8.7  16.3  185  22 11   8.0   4.4
 12000  -8.4  16.9  165  21 11   7.0   3.8 |  -7.5  18.5  190  19 10   7.5   4.1
 11750  -7.8  18.0  170  20 10   8.5   4.7 |  -7.0  19.4  195  18  9   7.2   4.0
 11500  -7.2  19.0  170  19 10   8.0   4.4 |  -6.5  20.3  200  16  8   7.0   3.9
 11250  -6.6  20.1  175  18  9   8.8   4.8 |  -5.9  21.4  200  15  8   7.9   4.4
 11000  -5.9  21.4  175  17  9   8.7   4.8 |  -5.3  22.5  205  14  7   8.6   4.7
 10750  -5.3  22.5  180  16  8   7.8   4.3 |  -4.7  23.5  210  13  7   8.2   4.5
 10500  -4.8  23.4  185  14  7   8.1   4.4 |  -4.0  24.8  215  11  6   8.4   4.6
 10250  -4.2  24.4  185  13  7   7.8   4.3 |  -3.4  25.9  220  10  5   8.2   4.5
 10000  -3.6  25.5  190  12  6   7.0   3.8 |  -2.8  27.0  230   9  5   7.0   3.8
  9750  -3.1  26.4  195  10  5   7.7   4.2 |  -2.3  27.9  235   8  4   7.4   4.1
  9500  -2.5  27.5  195   8  4   8.7   4.8 |  -1.7  28.9  245   7  4   8.6   4.7
  9250  -1.9  28.6  195   6  3   8.2   4.5 |  -1.1  30.0  255   6  3   7.9   4.3
  9000  -1.3  29.7  200   4  2   8.1   4.5 |  -0.6  30.9  275   6  3   6.9   3.8
  8750  -0.8  30.6  200   3  1   6.1   3.3 |  -0.2  31.6  295   5  3   5.7   3.1
  8500  -0.6  30.9  210   1  1   3.8   2.1 |   0.2  32.4  315   6  3   5.0   2.7
  8250  -0.3  31.5  360   1  0   6.6   3.6 |   0.5  32.9  330   8  4   6.1   3.4
  8000   0.3  32.5  350   1  1   9.6   5.3 |   0.9  33.6  335   9  4   7.6   4.2
  7750   0.9  33.6  340   1  1   7.6   4.2 |   1.4  34.5  335   9  5   7.0   3.8
  7500   1.3  34.3  325   2  1   5.7   3.1 |   1.8  35.2  340   9  4   6.1   3.4
  7250   1.7  35.1  320   3  1   6.9   3.8 |   2.2  36.0  335   8  4   5.8   3.2
  7000   2.2  36.0  320   3  1   7.9   4.3 |   2.6  36.7  335   8  4   5.4   3.0
  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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