Soaring Guidance
Issued by NWS Denver/Boulder, CO

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000
UXUS97 KBOU 161314
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0714 MDT Thursday, April 16, 2015

This forecast is for Thursday, April 16, 2015:

If the trigger temperature of 46.6 F/8.1 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 8799 ft MSL (3514 ft AGL)

Forecast maximum temperature................... 43.0 F/6.6 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................. 7081 ft MSL (1796 ft AGL)
Thermal soaring outlook for Friday 04/17....... Poor

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 PVA
Potential height of wave....................... 14411 ft MSL (9126 ft AGL)
Wave soaring outlook for Friday 04/17.......... Poor

Remarks... Snow

Sunrise/Sunset.................... 06:20:49 / 19:37:31 MDT
Total possible sunshine........... 13 hr 16 min 43 sec (796 min 43 sec)
Altitude of sun at 12:59:19 MDT... 60.44 degrees

Upper air data from rawinsonde observation taken on 04/16/2015 at 0600 MDT

Freezing level.................. 6164 ft MSL (879 ft AGL)
Convective condensation level... 12450 ft MSL (7165 ft AGL)
Lifted condensation level....... 9771 ft MSL (4485 ft AGL)
Lifted index.................... +5.9
K index......................... +22.4

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -57.6 -71.7   180   20   11   3.8   2.1  103.7 218.7    55.8      M    M
 45000  -53.4 -64.1   230   14    7   6.1   3.4   86.2 187.1    49.0      M    M
 40000  -48.2 -54.8   195   33   17   4.9   2.7   71.3 160.3    42.6      M    M
 38000  -49.3 -56.7   185   30   16   3.8   2.1   60.8 141.5    36.7      M    M
 36000  -49.1 -56.4   210   38   20 -11.4  -6.2   52.5 126.5    31.9      M    M
 34000  -50.2 -58.4   200   53   27   2.7   1.5   41.4 106.5    25.0      M    M
 32000  -51.1 -60.0   200   61   31   2.0   1.1   31.9  89.5    18.8      M    M
 30000  -49.1 -56.4   200   70   36   6.2   3.4   26.8  80.3    15.5      M    M
 29000  -47.1 -52.8   200   61   31   5.4   2.9   25.5  77.9    14.7      M    M
 28000  -45.1 -49.2   195   51   26   8.4   4.6   24.4  75.9    14.0      M    M
 27000  -42.5 -44.5   195   52   27   8.5   4.7   23.9  74.9    13.8      M    M
 26000  -40.1 -40.2   190   54   28   7.3   4.0   23.2  73.7    13.4      M    M
 25000  -37.9 -36.2   190   55   28   7.9   4.3   22.3  72.1    12.9      M    M
 24000  -35.5 -31.9   190   53   27   8.1   4.4   21.7  71.0    12.5      M    M
 23000  -32.8 -27.0   190   50   26   8.6   4.7   21.3  70.4    12.4      M    M
 22000  -30.3 -22.5   185   47   24   8.6   4.7   20.9  69.7    12.2      M    M
 21000  -27.8 -18.0   180   44   23   8.2   4.5   20.4  68.8    11.9      M    M
 20000  -25.3 -13.5   175   41   21   8.0   4.4   19.9  67.8    11.6      M    M
 19500  -24.1 -11.4   175   41   21   8.0   4.4   19.6  67.2    11.4      M    M
 19000  -22.9  -9.2   180   42   22   8.3   4.5   19.3  66.7    11.2      M    M
 18500  -21.6  -6.9   175   41   21   9.5   5.2   19.1  66.5    11.1      M    M
 18000  -20.4  -4.7   170   38   19   7.5   4.1   18.9  66.1    10.9      M    M
 17500  -19.5  -3.1   155   33   17   4.3   2.4   18.2  64.8    10.4      M    M
 17000  -18.5  -1.3   135   30   16   4.7   2.6   16.9  62.5     9.3      M    M
 16500  -17.8  -0.0   135   27   14   5.5   3.0   16.0  60.9     8.6      M    M
 16000  -16.8   1.8   135   23   12   7.7   4.2   15.6  60.1     8.2      M    M
 15500  -15.6   3.9   130   21   11   7.6   4.2   15.2  59.4     7.9      M    M
 15000  -14.5   5.9   130   19   10   7.6   4.2   14.9  58.8     7.6      M    M
 14500  -13.4   7.9   135   21   11   7.6   4.2   14.5  58.1     7.3      M    M
 14000  -12.3   9.9   135   23   12   7.3   4.0   14.2  57.5     7.0      M    M
 13500  -11.0  12.2   130   23   12  10.9   6.0   14.0  57.3     6.9      M    M
 13000   -9.6  14.7   130   23   12   7.6   4.2   13.9  57.1     6.8      M    M
 12500   -8.5  16.7   110   21   11   7.6   4.2   13.6  56.5     6.5      M    M
 12000   -7.4  18.7   090   22   11   7.8   4.3   13.3  55.9     6.1      M    M
 11500   -6.4  20.5   085   20   10   4.2   2.3   12.8  55.0     5.7      M    M
 11000   -6.0  21.2   075   18    9   2.5   1.4   11.7  53.0     4.7      M    M
 10500   -5.3  22.5   045   15    8   7.7   4.2   10.9  51.6     4.0      M    M
 10250   -4.7  23.5   030   15    8   9.0   4.9   10.8  51.4     3.8      M    M
 10000   -4.1  24.6   020   17    9   7.3   4.0   10.7  51.2     3.7      M    M
  9750   -3.7  25.3   015   19   10   3.2   1.8   10.3  50.6     3.4      M    M
  9500   -3.6  25.5   010   21   11  -2.1  -1.1    9.6  49.3     2.7      M    M
  9250   -3.9  25.0   010   23   12  -5.0  -2.8    8.5  47.3     1.7      M    M
  9000   -4.3  24.3   005   25   13  -4.2  -2.3    7.4  45.3     0.7      M    M
  8750   -4.4  24.1   005   25   13   2.2   1.2    6.5  43.7    -0.2    278  1.4
  8500   -4.0  24.8   360   25   13   7.1   3.9    6.2  43.2    -0.5    257  1.3
  8250   -3.5  25.7   360   25   13   5.8   3.2    5.9  42.6    -0.8    237  1.2
  8000   -3.1  26.4   360   25   13   5.4   3.0    5.6  42.1    -1.1    216  1.1
  7750   -2.6  27.3   360   25   13   6.5   3.6    5.3  41.5    -1.4    196  1.0
  7500   -2.2  28.0   360   25   13   1.8   1.0    5.0  40.9    -1.7    175  0.9
  7250   -2.3  27.9   360   24   12  -2.7  -1.5    4.1  39.3    -2.5    171  0.9
  7000   -2.3  27.9   360   24   12   5.3   2.9    3.4  38.1    -3.2    162  0.8
  6750   -1.6  29.1   005   21   11   9.7   5.3    3.3  37.9    -3.3    135  0.7
  6500   -0.9  30.4   005   18    9   8.5   4.7    3.2  37.8    -3.4    108  0.5
  6250   -0.3  31.5   010   15    8   8.9   4.9    3.2  37.7    -3.4     81  0.4
  6000    0.4  32.7   020   12    6   8.8   4.8    3.1  37.6    -3.5     54  0.3
  5750    1.0  33.8   015   10    5   8.8   4.9    3.0  37.5    -3.6     26  0.1
  5500    1.7  35.1   360    8    4  10.3   5.7    3.0  37.4    -3.6      M    M

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

           04/16/2015 at 0900 MDT          |       04/16/2015 at 1200 MDT
                                           |
K index... +24.7  LI... +273.7             | K index... +25.1  LI... +272.3
CAPE... 0.0  CIN... -4.5                   | CAPE... +87.4  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 -55.9 -68.6  240  13  7   3.1   1.7 | -55.9 -68.6  240  11  6   2.9   1.6
 45000 -51.3 -60.3  250  14  7   2.5   1.4 | -51.3 -60.3  230  12  6   1.8   1.0
 40000 -49.5 -57.1  200  27 14   1.1   0.6 | -48.7 -55.7  200  27 14   1.7   0.9
 38000 -49.6 -57.3  195  32 17  -1.7  -0.9 | -48.5 -55.3  200  32 17  -1.6  -0.9
 36000 -50.6 -59.1  200  36 19  -1.6  -0.9 | -49.5 -57.1  195  37 19  -1.6  -0.9
 34000 -51.5 -60.7  200  40 20   0.3   0.2 | -50.4 -58.7  195  41 21   0.3   0.2
 32000 -50.2 -58.4  190  49 25   2.3   1.3 | -49.0 -56.2  190  52 27   2.4   1.3
 30000 -48.7 -55.7  185  59 30   6.0   3.3 | -47.1 -52.8  185  63 33   6.4   3.5
 29000 -46.2 -51.2  175  55 28   8.3   4.5 | -45.3 -49.5  180  63 32   6.0   3.3
 28000 -43.1 -45.6  170  52 27   8.3   4.6 | -43.5 -46.3  180  62 32   6.0   3.3
 27000 -40.6 -41.1  165  50 26   8.2   4.5 | -41.8 -43.2  180  62 32   6.2   3.4
 26000 -38.4 -37.1  165  48 25   7.5   4.1 | -39.2 -38.6  180  59 31   9.0   4.9
 25000 -36.1 -33.0  170  46 24   7.5   4.1 | -36.5 -33.7  180  57 29   9.0   4.9
 24000 -33.9 -29.0  175  45 23   7.5   4.1 | -33.8 -28.8  180  54 28   9.2   5.0
 23000 -31.6 -24.9  180  43 22   7.9   4.3 | -31.4 -24.5  175  50 26   7.7   4.2
 22000 -29.2 -20.6  175  41 21   7.9   4.3 | -29.1 -20.4  175  47 24   7.7   4.2
 21000 -26.9 -16.4  175  38 20   7.9   4.3 | -26.9 -16.4  170  43 22   7.9   4.3
 20000 -24.6 -12.3  175  36 19   7.9   4.3 | -24.5 -12.1  170  40 21   8.0   4.4
 19500 -23.4 -10.1  175  35 18   7.9   4.3 | -23.3  -9.9  170  38 20   8.0   4.4
 19000 -22.2  -8.0  175  35 18   7.9   4.3 | -22.1  -7.8  170  37 19   8.0   4.4
 18500 -21.0  -5.8  175  34 17   7.8   4.3 | -20.9  -5.6  165  36 18   7.9   4.3
 18000 -19.9  -3.8  175  33 17   7.3   4.0 | -19.8  -3.6  165  34 17   7.5   4.1
 17500 -18.9  -2.0  170  31 16   7.4   4.0 | -18.7  -1.7  160  32 16   7.4   4.1
 17000 -17.8  -0.0  170  30 16   7.4   4.1 | -17.5   0.5  160  31 16   8.3   4.6
 16500 -16.7   1.9  170  30 15   7.4   4.1 | -16.3   2.7  155  30 16   8.3   4.6
 16000 -15.6   3.9  165  29 15   8.1   4.4 | -14.5   5.9  155  30 15   7.7   4.2
 15500 -14.4   6.1  160  28 14   8.6   4.7 | -13.4   7.9  155  30 15   7.8   4.3
 15000 -12.4   9.7  145  28 14   9.2   5.0 | -12.3   9.9  155  29 15   7.8   4.3
 14500 -11.0  12.2  140  28 15   9.3   5.1 | -11.1  12.0  155  29 15   7.8   4.3
 14000  -9.6  14.7  130  29 15   8.1   4.4 | -10.0  14.0  150  28 15   7.6   4.2
 13500  -8.5  16.7  120  28 14   7.2   4.0 |  -8.9  16.0  150  27 14   7.5   4.1
 13000  -7.4  18.7  115  27 14   5.0   2.8 |  -7.8  18.0  150  26 13   7.0   3.8
 12500  -7.1  19.2  100  24 13   2.7   1.5 |  -6.9  19.6  140  24 12   6.4   3.5
 12000  -6.8  19.8  085  24 12   3.7   2.1 |  -6.0  21.2  130  23 12   6.5   3.6
 11500  -6.1  21.0  075  22 11   5.5   3.0 |  -5.0  23.0  120  21 11   6.7   3.7
 11000  -5.4  22.3  060  20 11   6.2   3.4 |  -4.1  24.6  110  21 11   6.4   3.5
 10500  -4.4  24.1  050  19 10   7.1   3.9 |  -3.2  26.2  105  21 11   6.1   3.3
 10250  -3.9  25.0  045  19 10   6.8   3.7 |  -2.8  27.0  100  21 11   5.6   3.1
 10000  -3.5  25.7  040  19 10   3.9   2.2 |  -2.4  27.7  100  21 11   3.8   2.1
  9750  -3.2  26.2  040  19 10   5.8   3.2 |  -2.1  28.2  095  20 11   5.7   3.1
  9500  -2.6  27.3  040  19 10   9.1   5.0 |  -1.6  29.1  095  20 10   8.3   4.6
  9250  -2.0  28.4  040  20 10   7.4   4.1 |  -1.1  30.0  095  20 10   6.5   3.6
  9000  -1.6  29.1  040  20 10   2.4   1.3 |  -0.8  30.6  090  19 10  -0.3  -0.2
  8750  -1.6  29.1  040  20 10  -1.7  -0.9 |  -1.0  30.2  085  20 10  -4.0  -2.2
  8500  -1.7  28.9  040  20 10  -1.6  -0.9 |  -1.2  29.8  075  21 11  -2.5  -1.4
  8250  -1.8  28.8  035  20 10  -1.4  -0.8 |  -1.4  29.5  070  23 12  -3.4  -1.9
  8000  -1.9  28.6  030  21 11  -1.2  -0.7 |  -1.7  28.9  060  23 12  -4.8  -2.6
  7750  -2.0  28.4  025  23 12  -0.8  -0.4 |  -2.0  28.4  050  23 12  -2.2  -1.2
  7500  -2.0  28.4  020  24 12  -0.3  -0.2 |  -2.0  28.4  040  21 11   0.6   0.3
  7250  -2.0  28.4  015  25 13   2.1   1.2 |  -1.9  28.6  035  20 10   4.1   2.2
  7000  -1.7  28.9  010  23 12   3.5   1.9 |  -1.4  29.5  030  17  9   7.0   3.8
  6750  -1.5  29.3  005  21 11   4.1   2.2 |  -0.9  30.4  020  15  8   6.8   3.7
  6500  -1.1  30.0  355  19 10   7.7   4.2 |  -0.4  31.3  015  13  7   9.0   4.9
  6250  -0.4  31.3  355  17  9   9.7   5.3 |   0.3  32.5  015  12  6  10.1   5.5
  6000   0.3  32.5  355  15  8   9.0   4.9 |   1.0  33.8  010  10  5   9.9   5.4
  5750   1.0  33.8  350  13  7  11.2   6.2 |   1.8  35.2  005   8  4  10.5   5.8
  5500   2.1  35.8  350  12  6  18.3  10.0 |   2.7  36.9  005   7  4  13.9   7.6

           04/16/2015 at 1500 MDT          |       04/16/2015 at 1800 MDT
                                           |
K index... +9.2  LI... +271.1              | K index... +16.1  LI... +272.3
CAPE... +183.7  CIN... -20.0               | CAPE... +79.3  CIN... -58.9
                                           |
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 -56.1 -69.0  240  14  7   3.2   1.8 | -57.4 -71.3  240  16  8   3.7   2.1
 45000 -51.0 -59.8  225  22 11   1.8   1.0 | -51.6 -60.9  225  22 12   2.7   1.5
 40000 -48.5 -55.3  215  25 13   1.7   0.9 | -47.6 -53.7  205  28 15   2.7   1.5
 38000 -48.0 -54.4  210  27 14  -0.4  -0.2 | -47.2 -53.0  200  29 15  -1.9  -1.0
 36000 -48.2 -54.8  200  30 15  -0.4  -0.2 | -48.3 -54.9  195  27 14  -1.8  -1.0
 34000 -48.5 -55.3  195  33 17  -0.1  -0.0 | -49.4 -56.9  190  25 13   0.3   0.2
 32000 -48.2 -54.8  195  46 24   0.3   0.2 | -47.9 -54.2  195  32 17   2.2   1.2
 30000 -47.6 -53.7  200  56 29   6.8   3.8 | -46.3 -51.3  200  38 20   5.8   3.2
 29000 -45.7 -50.3  200  57 29   6.3   3.5 | -44.7 -48.5  200  40 20   5.4   3.0
 28000 -43.8 -46.8  200  58 30   6.3   3.5 | -43.1 -45.6  200  41 21   5.4   3.0
 27000 -41.9 -43.4  200  58 30   6.3   3.5 | -41.5 -42.7  200  43 22   5.6   3.1
 26000 -39.4 -38.9  200  58 30   8.8   4.8 | -39.1 -38.4  195  39 20   8.4   4.6
 25000 -36.8 -34.2  195  58 30   8.8   4.8 | -36.6 -33.9  190  35 18   8.4   4.6
 24000 -34.2 -29.6  195  57 29   8.9   4.9 | -34.1 -29.4  180  31 16   8.4   4.6
 23000 -31.7 -25.1  195  56 29   8.1   4.5 | -31.6 -24.9  180  31 16   8.4   4.6
 22000 -29.2 -20.6  195  55 28   8.1   4.5 | -29.1 -20.4  180  32 17   8.4   4.6
 21000 -26.8 -16.2  190  53 27   7.7   4.2 | -26.6 -15.9  180  34 17   8.0   4.4
 20000 -24.7 -12.5  190  49 25   6.9   3.8 | -24.4 -11.9  180  35 18   7.5   4.1
 19500 -23.6 -10.5  190  47 24   6.9   3.8 | -23.3  -9.9  180  36 19   7.6   4.1
 19000 -22.6  -8.7  190  45 23   7.0   3.8 | -22.2  -8.0  180  37 19   7.6   4.1
 18500 -21.6  -6.9  190  43 22   7.3   4.0 | -21.0  -5.8  180  38 19   7.6   4.1
 18000 -20.3  -4.5  185  40 21   8.5   4.7 | -19.9  -3.8  180  36 19   7.5   4.1
 17500 -19.1  -2.4  185  38 20   8.4   4.6 | -18.8  -1.8  180  34 18   7.4   4.1
 17000 -17.1   1.2  180  35 18   9.4   5.2 | -17.6   0.3  180  32 17   8.2   4.5
 16500 -15.6   3.9  180  34 17   9.4   5.2 | -15.8   3.6  175  28 14   8.1   4.5
 16000 -14.2   6.4  175  32 16   9.5   5.2 | -14.5   5.9  170  26 13   9.3   5.1
 15500 -12.8   9.0  175  30 16   9.6   5.2 | -13.1   8.4  165  24 12   9.2   5.0
 15000 -11.5  11.3  170  29 15   8.5   4.7 | -11.7  10.9  160  22 11   8.9   4.9
 14500 -10.2  13.6  165  28 14   8.4   4.6 | -10.4  13.3  160  21 11   8.9   4.9
 14000  -9.0  15.8  165  27 14   7.7   4.2 |  -9.0  15.8  160  20 10   8.4   4.6
 13500  -7.9  17.8  165  26 13   7.3   4.0 |  -7.8  18.0  160  19 10   8.2   4.5
 13000  -6.9  19.6  160  24 12   6.6   3.6 |  -6.5  20.3  160  19 10   7.8   4.3
 12500  -6.1  21.0  160  23 12   6.0   3.3 |  -5.4  22.3  160  17  9   7.3   4.0
 12000  -5.3  22.5  155  21 11   5.8   3.2 |  -4.3  24.3  160  16  8   5.7   3.1
 11500  -4.6  23.7  150  20 10   5.5   3.0 |  -3.8  25.2  160  15  7   4.3   2.3
 11000  -3.9  25.0  140  20 10   6.8   3.7 |  -3.3  26.1  155  13  7   4.3   2.4
 10500  -2.7  27.1  125  21 11   8.5   4.7 |  -2.9  26.8  140  14  7   4.7   2.6
 10250  -2.1  28.2  120  21 11   8.0   4.4 |  -2.7  27.1  135  15  7   2.2   1.2
 10000  -1.7  28.9  115  22 11   3.6   2.0 |  -2.7  27.1  130  15  8   3.2   1.7
  9750  -1.5  29.3  115  23 12   4.2   2.3 |  -2.2  28.0  130  15  8   9.7   5.3
  9500  -1.0  30.2  110  23 12   7.8   4.3 |  -1.4  29.5  125  16  8  12.1   6.6
  9250  -0.5  31.1  105  24 13   5.1   2.8 |  -0.6  30.9  120  16  8   9.0   4.9
  9000  -0.5  31.1  100  24 13  -5.0  -2.7 |  -0.2  31.6  115  15  8  -0.7  -0.4
  8750  -1.1  30.0  090  23 12 -10.5  -5.8 |  -0.5  31.1  105  13  7  -5.3  -2.9
  8500  -1.8  28.8  085  21 11 -10.9  -6.0 |  -0.9  30.4  090  11  6  -5.4  -3.0
  8250  -2.5  27.5  070  19 10  -4.9  -2.7 |  -1.2  29.8  070  10  5  -1.6  -0.9
  8000  -2.4  27.7  065  17  9   4.1   2.3 |  -1.0  30.2  055   8  4   3.8   2.1
  7750  -2.1  28.2  055  14  7   5.1   2.8 |  -0.8  30.6  030   8  4   3.4   1.9
  7500  -1.7  28.9  045  13  6   5.7   3.1 |  -0.5  31.1  010   8  4   3.3   1.8
  7250  -1.2  29.8  035  11  6   7.1   3.9 |  -0.3  31.5  355   9  5   3.4   1.9
  7000  -0.7  30.7  025  10  5   8.4   4.6 |  -0.0  32.0  335  10  5   3.7   2.0
  6750  -0.1  31.8  010   9  4   7.3   4.0 |   0.2  32.4  325  11  6   2.8   1.5
  6500   0.4  32.7  360   8  4   8.5   4.7 |   0.5  32.9  310  13  7   6.2   3.4
  6250   1.1  34.0  350   8  4  10.3   5.7 |   1.2  34.2  310  13  7  10.1   5.5
  6000   1.9  35.4  345   8  4   9.9   5.5 |   1.9  35.4  305  12  6   9.0   5.0
  5750   2.6  36.7  335   7  4  10.6   5.8 |   2.6  36.7  300  12  6  10.5   5.8
  5500   3.5  38.3  335   7  4  13.2   7.3 |   3.5  38.3  300  11  6  13.9   7.6
________________________________________________________________________________

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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