Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 171218
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0618 MDT Friday, March 17, 2017

This forecast is for Friday, March 17, 2017:

If the trigger temperature of 65.9 F/18.8 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1094 ft/min (5.6 m/s)
   Maximum height of thermals.................. 16920 ft MSL (11635 ft AGL)

Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 1300 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 9538 ft MSL (4252 ft AGL)
Thermal soaring outlook for Saturday 03/18..... Excellent

Wave Soaring Index............................. Good
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 18075 ft MSL (12790 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 18567 ft MSL (13282 ft AGL)
Wave soaring outlook for Saturday 03/18........ Poor

Remarks...

Sunrise/Sunset.................... 07:07:08 / 19:07:43 MDT
Total possible sunshine........... 12 hr 0 min 35 sec (720 min 35 sec)
Altitude of sun at 13:07:37 MDT... 49.20 degrees

Upper air data from rawinsonde observation taken on 03/17/2017 at 0600 MDT

Freezing level.................. 11899 ft MSL (6614 ft AGL)
Convective condensation level... 16675 ft MSL (11390 ft AGL)
Lifted condensation level....... 16925 ft MSL (11639 ft AGL)
Lifted index.................... +1.2
K index......................... +15.6

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  -60.7 -77.3   250   27   14   2.7   1.5   99.8 211.6    44.2      M    M
 45000  -62.2 -80.0   295   55   28   1.5   0.8   71.2 160.2    30.0      M    M
 40000  -67.0 -88.6   300   66   34   5.2   2.8   40.4 104.8    12.0      M    M
 38000  -63.6 -82.5   300   65   34   6.1   3.3   36.9  98.3     9.9      M    M
 36000  -58.6 -73.5   295   58   30   8.6   4.7   35.6  96.1     9.3      M    M
 34000  -53.5 -64.3   290   52   27   8.9   4.9   34.6  94.2     8.8      M    M
 32000  -48.1 -54.6   295   52   27   8.9   4.9   33.9  92.9     8.5      M    M
 30000  -42.3 -44.1   295   56   29   7.7   4.2   32.9  91.2     8.1      M    M
 29000  -40.0 -40.0   295   54   28   7.7   4.2   32.0  89.7     7.5      M    M
 28000  -37.7 -35.9   295   52   27   8.0   4.4   31.3  88.4     7.0      M    M
 27000  -35.1 -31.2   295   50   26   8.5   4.7   30.9  87.6     6.8      M    M
 26000  -32.6 -26.7   300   49   25   8.5   4.7   30.4  86.6     6.4      M    M
 25000  -30.1 -22.2   305   48   25   8.5   4.7   30.0  85.9     6.2      M    M
 24000  -27.6 -17.7   305   48   24   7.8   4.3   29.4  84.9     5.8      M    M
 23000  -25.3 -13.5   300   46   24   8.0   4.4   28.7  83.6     5.2      M    M
 22000  -22.7  -8.9   300   45   23   8.7   4.8   28.2  82.7     4.9      M    M
 21000  -20.1  -4.2   300   43   22   8.7   4.8   27.8  82.1     4.6      M    M
 20000  -17.5   0.5   295   42   22   8.7   4.8   27.6  81.6     4.4      M    M
 19500  -16.2   2.8   295   41   21   8.7   4.8   27.3  81.2     4.2      M    M
 19000  -14.9   5.2   290   40   21   8.6   4.7   27.1  80.8     4.1      M    M
 18500  -13.7   7.3   290   41   21   7.4   4.1   26.9  80.4     3.8      M    M
 18000  -13.2   8.2   290   41   21   1.1   0.6   25.8  78.4     2.9      M    M
 17500  -13.0   8.6   290   42   22   1.6   0.9   24.4  75.9     1.6      M    M
 17000  -12.8   9.0   285   43   22   1.5   0.8   23.0  73.4     0.4      M    M
 16500  -12.1  10.2   285   44   23   7.1   3.9   22.1  71.8    -0.4   1068  5.4
 16000  -11.2  11.8   285   45   23   6.6   3.6   21.6  70.9    -0.9   1024  5.2
 15500  -10.2  13.6   285   45   23   6.6   3.6   21.1  69.9    -1.4    980  5.0
 15000   -8.5  16.7   285   43   22   9.6   5.3   20.6  69.0    -1.8    906  4.6
 14500   -7.1  19.2   290   37   19   9.3   5.1   20.5  68.9    -1.9    850  4.3
 14000   -5.7  21.7   290   31   16   9.3   5.1   20.5  68.9    -1.9    793  4.0
 13500   -4.3  24.3   290   28   15   9.3   5.1   20.4  68.7    -2.0    736  3.7
 13000   -2.9  26.8   285   25   13   9.3   5.1   20.3  68.6    -2.1    680  3.5
 12500   -1.5  29.3   285   22   12   9.3   5.1   20.3  68.5    -2.2    623  3.2
 12000   -0.1  31.8   280   20   10   9.3   5.1   20.2  68.4    -2.2    566  2.9
 11500    1.3  34.3   280   17    9   9.3   5.1   20.1  68.2    -2.3    510  2.6
 11000    2.7  36.9   285   15    8   9.4   5.1   20.0  68.1    -2.4    453  2.3
 10500    4.1  39.4   270   16    8  10.1   5.5   19.9  67.9    -2.5    396  2.0
 10250    4.9  40.8   265   16    8  10.1   5.5   20.0  68.0    -2.5    366  1.9
 10000    5.5  41.9   265   17    9   7.4   4.1   19.9  67.8    -2.6    339  1.7
  9750    6.0  42.8   265   16    8   6.5   3.5   19.7  67.4    -2.8    317  1.6
  9500    6.5  43.7   265   16    8   6.7   3.7   19.4  67.0    -3.1    295  1.5
  9250    7.0  44.6   265   15    8   6.7   3.6   19.2  66.6    -3.3    273  1.4
  9000    7.5  45.5   265   15    8   6.7   3.7   19.0  66.1    -3.5    251  1.3
  8750    8.0  46.4   270   13    7   6.7   3.7   18.7  65.7    -3.8    229  1.2
  8500    8.5  47.3   275   12    6   6.7   3.7   18.5  65.3    -4.1    207  1.0
  8250    9.0  48.2   285   11    6   6.7   3.7   18.2  64.8    -4.3    185  0.9
  8000    9.5  49.1   295   10    5   6.7   3.7   18.0  64.4    -4.5    162  0.8
  7750    9.9  49.8   295    6    3   6.6   3.6   17.8  64.0    -4.8    140  0.7
  7500   10.4  50.7   290    3    2   6.9   3.8   17.5  63.6    -5.1    118  0.6
  7250   10.9  51.6   165    1    0   4.4   2.4   17.3  63.1    -5.4     98  0.5
  7000   11.2  52.2   125    4    2   7.4   4.1   16.9  62.4    -5.8     81  0.4
  6750   11.5  52.7   120    5    3  -7.0  -3.8   16.5  61.6    -6.2     64  0.3
  6500   10.4  50.7   115    7    4  -8.7  -4.8   14.6  58.4    -8.1     90  0.5
  6250   10.5  50.9   110    8    4   4.8   2.7   14.1  57.3    -8.7     78  0.4
  6000   10.7  51.3   110   10    5   0.9   0.5   13.5  56.2    -9.3     66  0.3
  5750   10.8  51.4   115    9    5   3.2   1.7   12.9  55.2    -9.9     55  0.3
  5500   11.0  51.8   125    9    5  -2.1  -1.1   12.3  54.1   -10.5     43  0.2

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

           03/17/2017 at 0900 MDT          |       03/17/2017 at 1200 MDT
                                           |
K index... +17.4  LI... +4.3               | K index... +16.5  LI... +4.9
CAPE... 0.0  CIN... -3.1                   | CAPE... 0.0  CIN... -6.2
                                           |
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 -65.6 -86.1  290  34 18  -0.2  -0.1 | -65.1 -85.2  285  32 16  -0.6  -0.3
 45000 -65.8 -86.4  300  52 27  -0.4  -0.2 | -66.0 -86.8  300  43 22  -0.4  -0.2
 40000 -67.0 -88.6  295  56 29  -0.8  -0.5 | -66.2 -87.2  315  48 25  -0.2  -0.1
 38000 -64.1 -83.4  295  55 28   8.6   4.7 | -63.2 -81.8  315  49 25   8.1   4.4
 36000 -58.3 -72.9  290  53 27   8.6   4.7 | -57.7 -71.9  320  47 24   8.1   4.4
 34000 -53.1 -63.6  295  52 27   8.8   4.8 | -52.6 -62.7  315  48 25   9.0   5.0
 32000 -47.8 -54.0  300  53 27   8.8   4.8 | -47.2 -53.0  310  51 26   9.0   5.0
 30000 -42.6 -44.7  305  52 27   8.7   4.8 | -41.7 -43.1  305  52 27   9.0   5.0
 29000 -39.9 -39.8  305  50 26   8.8   4.8 | -39.0 -38.2  305  51 26   9.0   5.0
 28000 -37.3 -35.1  305  48 25   8.8   4.8 | -36.3 -33.3  305  51 26   9.0   4.9
 27000 -34.7 -30.5  305  46 24   8.6   4.7 | -33.7 -28.7  310  49 25   8.0   4.4
 26000 -32.1 -25.8  300  45 23   8.6   4.7 | -31.3 -24.3  305  46 24   8.0   4.4
 25000 -29.5 -21.1  300  43 22   8.6   4.7 | -28.9 -20.0  305  44 23   8.0   4.4
 24000 -27.0 -16.6  300  42 22   8.3   4.5 | -26.5 -15.7  305  42 22   8.5   4.7
 23000 -24.5 -12.1  295  41 21   8.3   4.6 | -23.9 -11.0  300  42 21   8.5   4.7
 22000 -22.0  -7.6  295  41 21   8.3   4.6 | -21.4  -6.5  300  41 21   8.5   4.6
 21000 -19.7  -3.5  290  40 21   7.0   3.9 | -19.0  -2.2  295  41 21   7.3   4.0
 20000 -17.6   0.3  290  39 20   7.1   3.9 | -16.8   1.8  295  41 21   7.4   4.1
 19500 -16.5   2.3  290  39 20   7.1   3.9 | -15.8   3.6  295  41 21   7.4   4.1
 19000 -15.5   4.1  290  38 20   7.2   4.0 | -14.7   5.5  295  41 21   7.4   4.0
 18500 -14.3   6.3  290  37 19   5.2   2.9 | -13.4   7.9  295  40 21   5.2   2.8
 18000 -13.5   7.7  290  37 19   5.2   2.8 | -12.7   9.1  295  39 20   5.1   2.8
 17500 -12.8   9.0  290  36 19   4.9   2.7 | -12.1  10.2  290  38 20   4.1   2.3
 17000 -12.1  10.2  290  35 18   4.9   2.7 | -11.5  11.3  290  37 19   4.2   2.3
 16500 -11.3  11.7  290  34 18   6.1   3.4 | -10.8  12.6  290  36 19   5.0   2.8
 16000 -10.4  13.3  290  33 17   6.4   3.5 | -10.1  13.8  290  35 18   5.1   2.8
 15500  -9.4  15.1  295  31 16   6.7   3.7 |  -9.3  15.3  290  33 17   5.8   3.2
 15000  -8.4  16.9  295  30 15   7.1   3.9 |  -8.4  16.9  290  32 16   6.4   3.5
 14500  -7.3  18.9  295  28 15   7.3   4.0 |  -7.4  18.7  290  30 15   6.9   3.8
 14000  -6.1  21.0  300  27 14   8.1   4.4 |  -6.3  20.7  290  28 14   7.9   4.4
 13500  -4.9  23.2  300  25 13   8.0   4.4 |  -5.1  22.8  290  25 13   7.9   4.4
 13000  -3.8  25.2  300  23 12   7.8   4.3 |  -3.9  25.0  290  23 12   8.0   4.4
 12500  -2.6  27.3  305  21 11   7.8   4.3 |  -2.7  27.1  290  21 11   8.0   4.4
 12000  -1.4  29.5  305  19 10   8.0   4.4 |  -1.5  29.3  290  19 10   8.3   4.6
 11500  -0.2  31.6  300  17  9   7.9   4.4 |  -0.2  31.6  290  17  9   8.3   4.6
 11000   1.0  33.8  300  16  8   8.2   4.5 |   1.1  34.0  285  15  8   8.9   4.9
 10500   2.2  36.0  295  15  8   7.9   4.4 |   2.4  36.3  280  14  7   8.1   4.4
 10250   2.7  36.9  295  15  7   3.3   1.8 |   2.9  37.2  280  13  7   3.8   2.1
 10000   2.9  37.2  290  14  7   6.9   3.8 |   3.2  37.8  280  13  7   7.2   3.9
  9750   3.8  38.8  290  14  7  12.9   7.1 |   4.0  39.2  275  11  6  12.2   6.7
  9500   4.6  40.3  285  14  7  10.3   5.7 |   4.8  40.6  270  10  5   9.5   5.2
  9250   5.3  41.5  285  13  7   7.4   4.1 |   5.4  41.7  265   9  4   6.7   3.7
  9000   5.8  42.4  285  13  7   7.1   3.9 |   5.9  42.6  260   7  4   6.4   3.5
  8750   6.4  43.5  285  12  6   9.9   5.4 |   6.4  43.5  255   6  3   7.8   4.3
  8500   7.1  44.8  285  11  6   8.0   4.4 |   7.0  44.6  240   4  2   6.4   3.5
  8250   7.6  45.7  285  10  5   5.1   2.8 |   7.4  45.3  200   2  1   4.8   2.6
  8000   8.0  46.4  280   9  4   5.2   2.8 |   7.7  45.9  145   3  2   5.1   2.8
  7750   8.3  46.9  275   7  4   5.4   2.9 |   8.1  46.6  120   5  3   6.1   3.3
  7500   8.7  47.7  270   6  3   4.4   2.4 |   8.6  47.5  110   7  4   8.3   4.5
  7250   9.0  48.2  250   6  3   3.4   1.9 |   9.3  48.7  110   7  4   9.2   5.1
  7000   9.3  48.7  235   5  3   3.9   2.1 |  10.0  50.0  105   8  4   8.8   4.8
  6750   9.6  49.3  215   6  3   3.8   2.1 |  10.6  51.1  105   8  4   9.5   5.2
  6500   9.8  49.6  205   6  3   2.1   1.1 |  11.4  52.5  105   8  4  10.4   5.7
  6250  10.0  50.0  195   5  3   2.5   1.3 |  12.2  54.0  105   8  4  10.3   5.7
  6000  10.1  50.2  185   5  3  -1.7  -0.9 |  12.9  55.2  105   8  4  10.4   5.7
  5750   9.7  49.5  185   5  3  -5.5  -3.0 |  13.8  56.8  100   8  4  15.6   8.6
  5500   9.5  49.1  180   4  2   1.5   0.8 |  15.3  59.5  100   8  4  24.0  13.1

           03/17/2017 at 1500 MDT          |       03/17/2017 at 1800 MDT
                                           |
K index... +17.4  LI... +2.8               | K index... +19.2  LI... +1.1
CAPE... 0.0  CIN... -6.5                   | CAPE... 0.0  CIN... -8.9
                                           |
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 -64.6 -84.3  295  34 17  -1.3  -0.7 | -64.7 -84.5  305  26 13  -1.6  -0.9
 45000 -66.6 -87.9  300  46 24  -1.1  -0.6 | -67.0 -88.6  315  43 22  -1.1  -0.6
 40000 -67.6 -89.7  335  41 21  -0.3  -0.2 | -67.8 -90.0  295  45 23  -0.2  -0.1
 38000 -63.6 -82.5  330  42 22   9.2   5.0 | -63.5 -82.3  300  45 23   9.7   5.3
 36000 -58.1 -72.6  325  44 23   9.2   5.0 | -57.7 -71.9  305  44 23   9.7   5.3
 34000 -52.6 -62.7  315  45 23   9.5   5.2 | -52.1 -61.8  305  44 23   8.9   4.9
 32000 -46.9 -52.4  315  42 22   9.5   5.2 | -46.8 -52.2  310  42 22   8.9   4.9
 30000 -41.4 -42.5  310  42 22   9.0   5.0 | -41.4 -42.5  310  41 21   8.9   4.9
 29000 -38.0 -36.4  310  44 23   9.0   5.0 | -38.1 -36.6  310  40 21   8.9   4.9
 28000 -35.3 -31.5  310  46 24   9.1   5.0 | -35.4 -31.7  305  39 20   8.9   4.9
 27000 -32.8 -27.0  310  45 23   8.0   4.4 | -33.0 -27.4  310  38 20   7.9   4.3
 26000 -30.4 -22.7  310  44 22   8.0   4.4 | -30.6 -23.1  310  37 19   7.9   4.3
 25000 -28.0 -18.4  310  42 21   8.0   4.4 | -28.3 -18.9  310  36 19   7.9   4.3
 24000 -25.7 -14.3  305  40 21   7.6   4.1 | -26.0 -14.8  310  35 18   7.6   4.2
 23000 -23.4 -10.1  305  39 20   7.6   4.2 | -23.7 -10.7  305  35 18   7.6   4.2
 22000 -21.2  -6.2  305  38 19   7.6   4.2 | -21.4  -6.5  305  34 18   7.6   4.2
 21000 -19.0  -2.2  300  37 19   7.2   4.0 | -19.4  -2.9  305  33 17   6.6   3.6
 20000 -16.8   1.8  300  37 19   7.2   4.0 | -17.4   0.7  305  32 16   6.6   3.6
 19500 -15.8   3.6  300  36 19   7.2   4.0 | -16.4   2.5  300  31 16   6.6   3.6
 19000 -14.7   5.5  300  36 19   6.8   3.7 | -15.5   4.1  300  30 16   6.5   3.6
 18500 -13.8   7.2  300  36 18   5.8   3.2 | -14.5   5.9  300  29 15   6.3   3.4
 18000 -13.0   8.6  300  35 18   5.9   3.2 | -13.6   7.5  300  28 14   6.2   3.4
 17500 -12.2  10.0  300  35 18   5.2   2.9 | -12.7   9.1  295  27 14   6.8   3.7
 17000 -11.4  11.5  295  34 17   5.3   2.9 | -11.7  10.9  295  26 13   6.8   3.7
 16500 -10.7  12.7  295  33 17   5.5   3.0 | -10.7  12.7  290  25 13   7.4   4.1
 16000  -9.8  14.4  290  32 17   5.8   3.2 |  -9.5  14.9  285  25 13   7.9   4.4
 15500  -9.0  15.8  285  32 16   6.0   3.3 |  -8.4  16.9  280  25 13   8.1   4.4
 15000  -7.4  18.7  280  30 15   7.8   4.3 |  -6.5  20.3  270  24 12   8.5   4.7
 14500  -6.2  20.8  280  29 15   7.8   4.3 |  -5.3  22.5  265  24 12   8.6   4.7
 14000  -5.1  22.8  275  27 14   7.9   4.3 |  -4.0  24.8  265  22 11   8.7   4.8
 13500  -3.9  25.0  270  25 13   7.8   4.3 |  -2.8  27.0  260  20 10   8.5   4.7
 13000  -2.8  27.0  270  22 12   7.5   4.1 |  -1.6  29.1  255  18  9   8.2   4.5
 12500  -1.7  28.9  270  20 10   7.6   4.2 |  -0.4  31.3  250  17  8   8.2   4.5
 12000  -0.5  31.1  265  18  9   8.3   4.5 |   0.9  33.6  245  15  8   8.4   4.6
 11500   0.7  33.3  265  16  8   8.2   4.5 |   2.2  36.0  240  14  7   8.1   4.5
 11000   1.9  35.4  260  14  7   7.7   4.2 |   3.2  37.8  235  12  6   6.6   3.6
 10500   3.1  37.6  250  11  6   6.2   3.4 |   4.3  39.7  225  10  5   5.5   3.0
 10250   3.4  38.1  250  10  5   3.5   1.9 |   4.6  40.3  225   9  5   4.4   2.4
 10000   3.8  38.8  245   8  4   7.2   4.0 |   5.0  41.0  220   8  4   7.7   4.2
  9750   4.4  39.9  230   6  3  10.2   5.6 |   5.7  42.3  210   6  3   9.6   5.2
  9500   5.1  41.2  195   4  2   8.5   4.7 |   6.4  43.5  190   4  2   8.4   4.6
  9250   5.7  42.3  165   3  2   6.2   3.4 |   6.9  44.4  175   4  2   6.8   3.7
  9000   6.2  43.2  145   4  2   8.7   4.8 |   7.4  45.3  155   3  2   8.2   4.5
  8750   7.0  44.6  130   4  2  12.2   6.7 |   8.1  46.6  135   3  2  10.0   5.5
  8500   7.8  46.0  120   4  2  10.6   5.8 |   8.9  48.0  115   3  2   9.4   5.2
  8250   8.6  47.5  120   5  2   9.5   5.2 |   9.5  49.1  110   3  2   9.1   5.0
  8000   9.3  48.7  115   5  2  10.0   5.5 |  10.2  50.4  100   3  2   9.5   5.2
  7750  10.1  50.2  115   5  2  10.4   5.7 |  11.0  51.8  095   3  2  10.2   5.6
  7500  10.8  51.4  110   5  2  10.1   5.5 |  11.7  53.1  095   3  2   9.9   5.4
  7250  11.6  52.9  110   5  2   9.6   5.3 |  12.5  54.5  090   3  2   9.5   5.2
  7000  12.3  54.1  110   5  2  10.1   5.5 |  13.2  55.8  085   3  2   9.7   5.3
  6750  13.1  55.6  105   5  2  10.6   5.8 |  13.9  57.0  085   4  2  10.0   5.5
  6500  13.9  57.0  105   5  2  10.3   5.7 |  14.7  58.5  080   4  2  10.1   5.5
  6250  14.6  58.3  105   5  2  10.0   5.5 |  15.4  59.7  075   3  2   9.9   5.4
  6000  15.4  59.7  105   5  2  10.4   5.7 |  16.1  61.0  075   3  2  10.3   5.6
  5750  16.3  61.3  100   5  2  16.3   9.0 |  17.0  62.6  075   3  2  11.4   6.3
  5500  17.8  64.0  095   5  2  24.7  13.6 |  17.9  64.2  070   3  2  12.3   6.8
________________________________________________________________________________

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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