Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 201250
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0650 MDT Monday, April 20, 2015

This forecast is for Monday, April 20, 2015:

If the trigger temperature of 41.8 F/5.4 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 274 ft/min (1.4 m/s)
   Maximum height of thermals.................. 12544 ft MSL (7259 ft AGL)

Forecast maximum temperature................... 54.0 F/12.7 C
Time of trigger temperature.................... 1030 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 10924 ft MSL (5638 ft AGL)
Thermal soaring outlook for Tuesday 04/21...... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 30187 ft MSL (24902 ft AGL)
Wave soaring outlook for Tuesday 04/21......... Poor

Remarks...

Sunrise/Sunset.................... 06:15:01 / 19:41:32 MDT
Total possible sunshine........... 13 hr 26 min 31 sec (806 min 31 sec)
Altitude of sun at 12:58:27 MDT... 61.84 degrees

Upper air data from rawinsonde observation taken on 04/20/2015 at 0600 MDT

Freezing level.................. 6007 ft MSL (722 ft AGL)
Convective condensation level... 13824 ft MSL (8539 ft AGL)
Lifted condensation level....... 13611 ft MSL (8326 ft AGL)
Lifted index.................... +2.4
K index......................... +15.3

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  -56.8 -70.2   280   24   12   6.0   3.3  106.4 223.5    53.7      M    M
 45000  -54.3 -65.7   270   40   21  10.3   5.6   85.8 186.5    44.9      M    M
 40000  -48.9 -56.0   275   46   24 -12.2  -6.7   71.3 160.3    38.4      M    M
 38000  -56.0 -68.8   295   39   20   7.3   4.0   51.6 125.0    26.4      M    M
 36000  -54.3 -65.7   295   43   22   6.6   3.6   45.4 113.8    22.8      M    M
 34000  -52.0 -61.6   295   48   25  -5.5  -3.0   39.2 102.6    19.1      M    M
 32000  -50.8 -59.4   300   57   29   7.1   3.9   32.7  90.9    14.9      M    M
 30000  -47.9 -54.2   305   65   33  -4.7  -2.6   28.8  83.8    12.3      M    M
 29000  -47.4 -53.3   305   63   32   5.2   2.9   25.6  78.0    10.1      M    M
 28000  -46.3 -51.3   305   60   31   8.9   4.9   23.1  73.6     8.3      M    M
 27000  -43.9 -47.0   310   58   30   8.6   4.7   22.5  72.4     7.9      M    M
 26000  -41.2 -42.2   310   55   29   9.1   5.0   22.2  71.9     7.8      M    M
 25000  -38.4 -37.1   310   53   27   9.3   5.1   22.0  71.6     7.8      M    M
 24000  -35.8 -32.4   305   52   27   6.8   3.7   21.6  70.8     7.5      M    M
 23000  -33.6 -28.5   305   50   26   7.5   4.1   20.6  69.1     6.9      M    M
 22000  -31.4 -24.5   300   49   25   7.2   4.0   19.8  67.7     6.3      M    M
 21000  -28.8 -19.8   295   49   25  11.7   6.4   19.5  67.0     6.0      M    M
 20000  -25.8 -14.4   290   48   25   8.9   4.9   19.6  67.3     6.1      M    M
 19500  -24.7 -12.5   290   47   24   6.8   3.7   19.2  66.5     5.8      M    M
 19000  -23.7 -10.7   290   46   24   6.9   3.8   18.6  65.6     5.4      M    M
 18500  -22.6  -8.7   290   45   23   6.8   3.7   18.2  64.7     5.0      M    M
 18000  -21.6  -6.9   290   44   23   6.5   3.6   17.8  64.0     4.6      M    M
 17500  -20.8  -5.4   295   41   21   6.1   3.3   16.9  62.5     3.9      M    M
 17000  -19.7  -3.5   295   39   20   8.2   4.5   16.6  61.8     3.6      M    M
 16500  -18.1  -0.6   300   36   18   6.6   3.6   15.9  60.7     3.0      M    M
 16000  -17.1   1.2   305   34   17   6.8   3.8   15.4  59.7     2.6      M    M
 15500  -16.1   3.0   310   33   17   6.9   3.8   14.9  58.8     2.2      M    M
 15000  -15.0   5.0   315   33   17   7.0   3.9   14.5  58.0     1.8      M    M
 14500  -14.0   6.8   315   32   17   7.3   4.0   14.0  57.3     1.4      M    M
 14000  -12.9   8.8   320   32   16   7.4   4.0   13.6  56.6     1.0      M    M
 13500  -11.8  10.8   310   32   16   7.7   4.2   13.3  55.9     0.6      M    M
 13000  -10.7  12.7   300   32   16   7.7   4.2   12.9  55.3     0.3      M    M
 12500   -9.6  14.7   295   29   15   7.8   4.3   12.6  54.7    -0.1    464  2.4
 12000   -8.8  16.2   290   26   14   3.3   1.8   11.9  53.4    -0.7    425  2.2
 11500   -8.2  17.2   275   21   11   3.2   1.8   10.9  51.6    -1.7    393  2.0
 11000   -7.8  18.0   260   18    9 -10.1  -5.5    9.8  49.6    -2.8    368  1.9
 10500   -8.6  16.5   255   13    7   9.4   5.1    7.4  45.3    -5.0    376  1.9
 10250   -8.1  17.4   255   11    6   6.9   3.8    7.2  44.9    -5.2    352  1.8
 10000   -7.5  18.5   250    9    5   6.3   3.5    7.0  44.5    -5.4    329  1.7
  9750   -7.2  19.0   245    8    4   4.9   2.7    6.6  43.9    -5.8    310  1.6
  9500   -6.8  19.8   245    7    4   4.5   2.5    6.2  43.2    -6.2    292  1.5
  9250   -6.5  20.3   240    7    3   3.8   2.1    5.8  42.4    -6.6    275  1.4
  9000   -6.1  21.0   235    6    3   4.8   2.7    5.3  41.6    -7.0    257  1.3
  8750   -5.7  21.7   235    4    2   5.2   2.8    5.0  40.9    -7.4    237  1.2
  8500   -5.3  22.5   235    3    2   5.7   3.2    4.6  40.3    -7.7    218  1.1
  8250   -4.8  23.4   235    1    1   8.1   4.5    4.4  39.9    -7.9    195  1.0
  8000   -4.1  24.6   000    0    0   9.5   5.2    4.3  39.8    -8.0    167  0.8
  7750   -3.4  25.9   045    2    1   8.1   4.5    4.3  39.7    -8.1    139  0.7
  7500   -2.9  26.8   045    4    2   7.1   3.9    4.1  39.4    -8.3    116  0.6
  7250   -2.4  27.7   045    6    3   7.6   4.2    3.9  39.0    -8.5     92  0.5
  7000   -1.8  28.8   045    8    4   7.7   4.2    3.8  38.8    -8.7     68  0.3
  6750   -1.2  29.8   040    9    4   8.0   4.4    3.6  38.5    -8.9     44  0.2
  6500   -0.7  30.7   040    9    5   6.6   3.6    3.4  38.2    -9.1     19  0.1
  6250   -0.3  31.5   035   10    5   4.3   2.3    3.1  37.6    -9.5      1  0.0
  6000   -0.0  32.0   035   11    6   4.0   2.2    2.7  36.8   -10.0      M    M
  5750    0.4  32.7   030   10    5   8.2   4.5    2.3  36.2   -10.4      M    M
  5500    1.2  34.2   025    8    4  14.7   8.0    2.5  36.5   -10.3      M    M

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

           04/20/2015 at 0900 MDT          |       04/20/2015 at 1200 MDT
                                           |
K index... +8.7  LI... +275.6              | K index... +13.7  LI... +275.4
CAPE... 0.0  CIN... -0.3                   | CAPE... 0.0  CIN... -1.0
                                           |
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 -55.5 -67.9  270  28 15   2.1   1.1 | -55.3 -67.5  275  29 15   1.6   0.9
 45000 -52.4 -62.3  280  37 19   2.3   1.3 | -52.9 -63.2  280  36 19   1.8   1.0
 40000 -54.4 -65.9  290  42 22  -1.6  -0.9 | -55.0 -67.0  295  40 21  -1.7  -0.9
 38000 -55.0 -67.0  295  45 23   1.0   0.6 | -55.6 -68.1  300  42 22   1.1   0.6
 36000 -54.4 -65.9  300  47 24   1.1   0.6 | -54.8 -66.6  300  43 22   1.2   0.7
 34000 -53.6 -64.5  305  50 26   2.4   1.3 | -54.0 -65.2  305  45 23   3.1   1.7
 32000 -51.2 -60.2  305  49 25   4.0   2.2 | -51.2 -60.2  305  44 23   4.6   2.5
 30000 -48.7 -55.7  310  48 25   6.0   3.3 | -48.3 -54.9  305  43 22   6.7   3.7
 29000 -46.6 -51.9  310  48 25   7.1   3.9 | -46.1 -51.0  305  42 21   7.4   4.1
 28000 -44.5 -48.1  310  49 25   7.1   3.9 | -43.9 -47.0  305  40 21   7.4   4.1
 27000 -42.4 -44.3  310  49 25   7.0   3.9 | -41.7 -43.1  305  39 20   7.4   4.1
 26000 -40.1 -40.2  310  50 26   7.9   4.3 | -39.5 -39.1  305  38 20   7.2   4.0
 25000 -37.7 -35.9  310  50 26   7.9   4.3 | -37.3 -35.1  305  38 19   7.2   4.0
 24000 -35.4 -31.7  310  50 26   7.9   4.3 | -35.1 -31.2  310  37 19   7.2   3.9
 23000 -32.8 -27.0  310  48 24   8.8   4.9 | -32.8 -27.0  305  36 18   8.3   4.6
 22000 -30.2 -22.4  305  42 22   8.9   4.9 | -30.3 -22.5  305  34 18   8.4   4.6
 21000 -27.5 -17.5  305  37 19   8.9   4.9 | -27.8 -18.0  305  32 17   8.3   4.6
 20000 -25.2 -13.4  310  37 19   7.3   4.0 | -25.4 -13.7  310  33 17   7.7   4.2
 19500 -24.1 -11.4  315  38 20   7.3   4.0 | -24.3 -11.7  310  33 17   7.7   4.2
 19000 -23.0  -9.4  315  39 20   7.3   4.0 | -23.1  -9.6  315  33 17   7.7   4.2
 18500 -21.9  -7.4  320  40 21   7.3   4.0 | -22.0  -7.6  315  34 17   7.7   4.2
 18000 -20.3  -4.5  320  39 20   7.4   4.1 | -20.8  -5.4  315  33 17   7.3   4.0
 17500 -19.2  -2.6  320  38 19   7.5   4.1 | -19.2  -2.6  320  31 16   7.3   4.0
 17000 -18.1  -0.6  320  37 19   6.8   3.7 | -18.2  -0.8  320  31 16   6.8   3.8
 16500 -17.1   1.2  320  37 19   6.9   3.8 | -17.1   1.2  320  32 16   6.9   3.8
 16000 -16.1   3.0  320  36 19   6.6   3.6 | -16.1   3.0  320  32 17   7.0   3.8
 15500 -15.1   4.8  320  35 18   6.6   3.6 | -15.1   4.8  320  33 17   7.1   3.9
 15000 -14.1   6.6  320  35 18   6.4   3.5 | -14.1   6.6  320  33 17   7.0   3.8
 14500 -13.3   8.1  320  32 17   6.2   3.4 | -13.1   8.4  320  33 17   6.9   3.8
 14000 -12.4   9.7  325  30 15   6.5   3.6 | -12.1  10.2  315  32 16   7.0   3.8
 13500 -11.3  11.7  325  28 14   7.2   4.0 | -11.0  12.2  320  30 15   7.2   4.0
 13000 -10.3  13.5  330  25 13   7.3   4.0 |  -9.9  14.2  320  28 14   7.2   4.0
 12500  -9.2  15.4  335  24 12   7.6   4.2 |  -8.9  16.0  320  25 13   7.2   4.0
 12000  -8.1  17.4  335  23 12   7.3   4.0 |  -7.8  18.0  320  22 11   7.5   4.1
 11500  -7.2  19.0  330  22 11   6.0   3.3 |  -6.7  19.9  320  19 10   8.2   4.5
 11000  -6.3  20.7  325  20 10   5.2   2.8 |  -5.5  22.1  320  17  9   7.9   4.3
 10500  -5.8  21.6  320  17  9   2.3   1.3 |  -4.4  24.1  320  15  8   7.1   3.9
 10250  -5.6  21.9  315  16  8   2.8   1.5 |  -3.9  25.0  325  15  8   6.4   3.5
 10000  -5.5  22.1  310  14  7   1.6   0.9 |  -3.4  25.9  325  14  7   9.1   5.0
  9750  -5.4  22.3  310  13  7   0.6   0.3 |  -2.6  27.3  325  13  7   8.6   4.7
  9500  -5.4  22.3  305  11  6   1.0   0.6 |  -2.2  28.0  320  13  7   5.6   3.1
  9250  -5.3  22.5  295   9  5   0.9   0.5 |  -1.7  28.9  320  12  6   6.6   3.6
  9000  -5.2  22.6  285   8  4   1.8   1.0 |  -1.3  29.7  320  11  6   4.8   2.6
  8750  -5.0  23.0  275   7  3   4.0   2.2 |  -1.0  30.2  320  10  5   3.3   1.8
  8500  -4.7  23.5  265   5  3   4.9   2.7 |  -0.8  30.6  320   7  4   3.5   1.9
  8250  -4.3  24.3  255   5  2   4.8   2.7 |  -0.5  31.1  315   5  3   3.1   1.7
  8000  -3.9  25.0  240   4  2   5.0   2.8 |  -0.4  31.3  305   3  2   2.0   1.1
  7750  -3.5  25.7  225   4  2   5.7   3.1 |  -0.2  31.6  245   2  1   2.8   1.5
  7500  -3.1  26.4  215   4  2   6.3   3.5 |   0.0  32.0  205   2  1   2.9   1.6
  7250  -2.6  27.3  205   4  2   5.9   3.2 |   0.3  32.5  190   3  2   6.8   3.7
  7000  -2.2  28.0  205   4  2   5.9   3.2 |   1.0  33.8  185   3  2  10.8   5.9
  6750  -1.8  28.8  200   5  2   5.2   2.8 |   1.7  35.1  185   3  2   9.5   5.2
  6500  -1.4  29.5  205   5  2   6.8   3.7 |   2.4  36.3  185   3  2  10.0   5.5
  6250  -0.8  30.6  205   5  2   9.6   5.2 |   3.2  37.8  185   3  2  10.8   5.9
  6000  -0.2  31.6  205   4  2   8.9   4.9 |   4.0  39.2  185   3  1  10.7   5.9
  5750   0.5  32.9  205   4  2  11.2   6.2 |   4.8  40.6  185   3  1  11.7   6.4
  5500   1.6  34.9  205   4  2  18.3  10.0 |   5.9  42.6  190   3  1  18.4  10.1

           04/20/2015 at 1500 MDT          |       04/20/2015 at 1800 MDT
                                           |
K index... +20.8  LI... +273.1             | K index... +22.2  LI... +272.3
CAPE... +20.0  CIN... -39.7                | CAPE... +75.4  CIN... -43.0
                                           |
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 -56.0 -68.8  270  29 15   1.1   0.6 | -56.0 -68.8  280  30 15   1.1   0.6
 45000 -54.3 -65.7  280  35 18   1.3   0.7 | -54.3 -65.7  285  40 21   1.3   0.7
 40000 -55.4 -67.7  295  37 19  -0.8  -0.4 | -56.2 -69.2  295  38 20  -1.4  -0.8
 38000 -55.5 -67.9  300  39 20   1.3   0.7 | -56.5 -69.7  300  38 20   1.5   0.8
 36000 -54.6 -66.3  305  40 21   1.4   0.8 | -55.6 -68.1  300  39 20   1.6   0.9
 34000 -53.6 -64.5  305  42 22   3.9   2.1 | -54.4 -65.9  305  40 21   5.1   2.8
 32000 -50.6 -59.1  305  42 22   5.1   2.8 | -50.6 -59.1  305  40 20   6.2   3.4
 30000 -47.4 -53.3  305  42 22   6.6   3.6 | -46.8 -52.2  310  40 20   7.2   3.9
 29000 -45.4 -49.7  305  42 22   6.9   3.8 | -44.7 -48.5  310  40 21   7.2   4.0
 28000 -43.3 -45.9  305  42 22   6.9   3.8 | -42.5 -44.5  310  41 21   7.2   4.0
 27000 -41.2 -42.2  300  42 22   6.9   3.8 | -40.3 -40.5  310  41 21   7.3   4.0
 26000 -39.1 -38.4  300  42 22   7.2   4.0 | -38.3 -36.9  310  42 21   6.8   3.7
 25000 -36.9 -34.4  305  41 21   7.2   4.0 | -36.2 -33.2  310  42 22   6.8   3.8
 24000 -34.8 -30.6  305  41 21   7.2   4.0 | -34.2 -29.6  310  42 22   6.8   3.7
 23000 -32.5 -26.5  305  40 21   8.0   4.4 | -32.0 -25.6  305  42 22   7.7   4.2
 22000 -30.1 -22.2  305  39 20   8.1   4.4 | -29.7 -21.5  310  41 21   7.7   4.2
 21000 -27.6 -17.7  305  39 20   8.1   4.4 | -27.4 -17.3  310  41 21   7.7   4.2
 20000 -25.3 -13.5  305  37 19   7.7   4.2 | -25.1 -13.2  310  40 20   7.8   4.3
 19500 -24.2 -11.6  305  37 19   7.7   4.2 | -23.9 -11.0  310  39 20   7.8   4.3
 19000 -23.0  -9.4  305  36 19   7.7   4.3 | -22.8  -9.0  310  39 20   7.8   4.3
 18500 -21.9  -7.4  305  35 18   7.8   4.3 | -21.6  -6.9  315  39 20   7.8   4.3
 18000 -20.7  -5.3  305  35 18   7.6   4.2 | -20.5  -4.9  315  38 20   7.7   4.2
 17500 -19.1  -2.4  305  34 17   7.6   4.2 | -18.8  -1.8  315  37 19   7.7   4.2
 17000 -18.0  -0.4  305  33 17   7.1   3.9 | -17.7   0.1  315  36 19   7.3   4.0
 16500 -16.9   1.6  305  31 16   7.2   3.9 | -16.6   2.1  315  35 18   7.3   4.0
 16000 -15.8   3.6  300  30 16   7.2   4.0 | -15.5   4.1  315  34 18   7.8   4.3
 15500 -14.8   5.4  300  29 15   7.3   4.0 | -14.3   6.3  315  33 17   7.8   4.3
 15000 -13.7   7.3  295  27 14   7.5   4.1 | -13.1   8.4  315  32 17   8.4   4.6
 14500 -12.6   9.3  295  26 14   7.6   4.2 | -11.9  10.6  310  31 16   8.7   4.8
 14000 -11.4  11.5  295  25 13   8.1   4.4 | -10.6  12.9  310  30 15   8.8   4.8
 13500 -10.2  13.6  295  25 13   8.6   4.7 |  -9.3  15.3  305  29 15   8.8   4.8
 13000  -8.9  16.0  295  24 12   8.5   4.6 |  -8.0  17.6  305  28 14   8.6   4.7
 12500  -7.7  18.1  295  22 11   7.9   4.3 |  -6.7  19.9  305  26 13   8.2   4.5
 12000  -6.5  20.3  295  20 10   7.8   4.3 |  -5.5  22.1  305  24 13   8.1   4.4
 11500  -5.4  22.3  295  17  9   7.3   4.0 |  -4.4  24.1  305  22 11   7.6   4.2
 11000  -4.4  24.1  295  14  7   7.0   3.8 |  -3.3  26.1  305  19 10   7.3   4.0
 10500  -3.4  25.9  300  12  6   5.9   3.2 |  -2.3  27.9  300  16  8   6.1   3.4
 10250  -3.0  26.6  300  11  5   6.4   3.5 |  -1.9  28.6  300  15  8   7.1   3.9
 10000  -2.5  27.5  305   9  5   8.3   4.6 |  -1.3  29.7  300  13  7   8.9   4.9
  9750  -1.8  28.8  305   8  4   7.5   4.1 |  -0.6  30.9  300  11  6   8.0   4.4
  9500  -1.4  29.5  310   6  3   6.1   3.3 |  -0.1  31.8  295  10  5   7.0   3.9
  9250  -0.9  30.4  315   5  2   6.3   3.5 |   0.4  32.7  295   8  4   7.3   4.0
  9000  -0.4  31.3  320   3  2   6.4   3.5 |   1.0  33.8  290   7  4   7.5   4.1
  8750   0.1  32.2  325   2  1   7.4   4.0 |   1.6  34.9  285   6  3   7.3   4.0
  8500   0.6  33.1  325   2  1   7.7   4.2 |   2.1  35.8  280   5  3   6.9   3.8
  8250   1.2  34.2  335   1  1   8.0   4.4 |   2.6  36.7  275   4  2   7.3   4.0
  8000   1.8  35.2  345   1  0   9.0   4.9 |   3.2  37.8  265   3  2   8.2   4.5
  7750   2.4  36.3  355   1  0   9.0   5.0 |   3.7  38.7  265   2  1   8.3   4.6
  7500   3.1  37.6  360   1  0   8.3   4.6 |   4.3  39.7  265   2  1   7.7   4.2
  7250   3.7  38.7  005   1  0   9.9   5.4 |   4.9  40.8  260   1  1   9.0   4.9
  7000   4.5  40.1  005   1  0  11.7   6.4 |   5.6  42.1  265   1  0  10.4   5.7
  6750   5.4  41.7  005   1  0   9.7   5.3 |   6.4  43.5  270   1  0   9.9   5.4
  6500   6.0  42.8  360   1  0   9.1   5.0 |   7.1  44.8  265   1  0   9.9   5.5
  6250   6.8  44.2  355   1  0  10.7   5.8 |   7.9  46.2  265   1  0  10.5   5.8
  6000   7.6  45.7  355   1  0  11.1   6.1 |   8.7  47.7  270   1  0  11.2   6.1
  5750   8.4  47.1  355   1  0  10.6   5.8 |   9.5  49.1  275   1  0   9.5   5.2
  5500   9.3  48.7  345   1  1  15.8   8.7 |  10.2  50.4  285   1  1   9.6   5.3
________________________________________________________________________________

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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