Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

000
UXUS97 KBOU 251238
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0637 MDT Saturday, July 25, 2015

This forecast is for Saturday, July 25, 2015:

If the trigger temperature of 84.5 F/29.1 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 938 ft/min (4.8 m/s)
   Maximum height of thermals.................. 15933 ft MSL (10648 ft AGL)

Forecast maximum temperature................... 93.0 F/34.3 C
Time of trigger temperature.................... 1100 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................. 13564 ft MSL (8278 ft AGL)
Thermal soaring outlook for Sunday 07/26....... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 16838 ft MSL (11553 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 19542 ft MSL (14257 ft AGL)
Wave soaring outlook for Sunday 07/26.......... Poor

Remarks... None

Sunrise/Sunset.................... 05:52:03 / 20:20:10 MDT
Total possible sunshine........... 14 hr 28 min 7 sec (868 min 7 sec)
Altitude of sun at 13:05:56 MDT... 69.80 degrees

Upper air data from rawinsonde observation taken on 07/25/2015 at 0600 MDT

Freezing level.................. 17567 ft MSL (12282 ft AGL)
Convective condensation level... 18739 ft MSL (13454 ft AGL)
Lifted condensation level....... 17531 ft MSL (12246 ft AGL)
Lifted index.................... +0.5
K index......................... +23.2

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  -71.7 -97.1   275   39   20  -1.3  -0.7   72.1 161.8    22.3      M    M
 45000  -63.0 -81.4   245   42   21   8.3   4.5   62.0 143.7    17.7      M    M
 40000  -51.4 -60.5   245   52   27   8.5   4.7   56.5 133.6    15.2      M    M
 38000  -46.3 -51.3   245   56   29   8.5   4.7   55.5 132.0    15.0      M    M
 36000  -41.2 -42.2   240   50   26   8.6   4.7   54.4 129.9    14.5      M    M
 34000  -35.8 -32.4   240   46   24   9.6   5.2   53.7 128.6    14.4      M    M
 32000  -30.6 -23.1   240   42   22   6.5   3.6   52.8 127.0    14.1      M    M
 30000  -26.4 -15.5   250   43   22   9.2   5.0   50.7 123.2    12.7      M    M
 29000  -24.6 -12.3   250   41   21   8.0   4.4   48.3 118.9    11.0      M    M
 28000  -22.5  -8.5   250   39   20   7.1   3.9   47.3 117.2    10.4      M    M
 27000  -20.3  -4.5   255   37   19   7.2   4.0   46.4 115.5     9.8      M    M
 26000  -18.4  -1.1   255   36   18   0.3   0.2   45.2 113.4     8.9      M    M
 25000  -16.2   2.8   255   34   17   6.6   3.6   44.3 111.8     8.3      M    M
 24000  -14.1   6.6   260   28   14   5.9   3.2   43.2 109.7     7.6      M    M
 23000  -12.0  10.4   265   22   12   7.2   4.0   42.1 107.8     6.8      M    M
 22000   -9.8  14.4   270   17    9   7.4   4.0   41.2 106.2     6.1      M    M
 21000   -8.0  17.6   260    8    4   5.2   2.8   39.8 103.7     5.0      M    M
 20000   -6.8  19.8   240   11    6   7.5   4.1   38.2 100.7     3.3      M    M
 19500   -5.8  21.6   230   12    6   8.2   4.5   37.7  99.8     2.9      M    M
 19000   -4.2  24.4   225   12    6   9.4   5.1   37.6  99.7     3.1      M    M
 18500   -2.7  27.1   225   10    5   8.8   4.8   37.6  99.6     3.2      M    M
 18000   -1.3  29.7   225    9    4   8.7   4.8   37.4  99.3     3.1      M    M
 17500   -0.0  32.0   230    7    4   8.3   4.5   37.2  99.0     2.9      M    M
 17000    1.3  34.3   230    5    3   1.9   1.1   37.1  98.7     2.8      M    M
 16500    0.7  33.3   235    4    2   5.9   3.2   35.3  95.5     0.8      M    M
 16000    1.8  35.2   240    2    1   5.5   3.0   34.9  94.8     0.4      M    M
 15500    1.9  35.4   280    1    1  -0.3  -0.1   33.5  92.3    -1.0    929  4.7
 15000    2.0  35.6   335    2    1   4.6   2.5   32.2  90.0    -2.3    910  4.6
 14500    3.7  38.7   360    4    2   8.7   4.8   31.7  89.1    -2.8    836  4.2
 14000    5.1  41.2   005    5    3   8.8   4.8   31.6  88.8    -2.9    780  4.0
 13500    6.4  43.5   005    6    3   8.6   4.7   31.4  88.5    -3.1    727  3.7
 13000    7.6  45.7   010    7    4   8.6   4.7   31.2  88.1    -3.3    675  3.4
 12500    8.9  48.0   010    8    4   8.6   4.7   31.0  87.8    -3.6    623  3.2
 12000   10.1  50.2   010    9    5   8.6   4.7   30.9  87.5    -3.8    571  2.9
 11500   11.4  52.5   355    8    4   8.9   4.9   30.7  87.2    -4.0    519  2.6
 11000   12.7  54.9   340    7    4   9.0   4.9   30.6  87.0    -4.1    464  2.4
 10500   14.1  57.4   320    7    4   9.0   4.9   30.4  86.8    -4.2    408  2.1
 10250   14.7  58.5   320    7    3   8.9   4.9   30.4  86.7    -4.3    381  1.9
 10000   15.4  59.7   320    6    3   8.9   4.9   30.3  86.6    -4.4    353  1.8
  9750   16.1  61.0   320    6    3   8.9   4.9   30.3  86.5    -4.5    326  1.7
  9500   16.8  62.2   320    6    3   9.0   4.9   30.2  86.3    -4.5    298  1.5
  9250   17.4  63.3   320    5    3   8.6   4.7   30.1  86.3    -4.6    271  1.4
  9000   18.0  64.4   320    5    3   7.3   4.0   30.0  86.0    -4.7    246  1.2
  8750   18.5  65.3   320    6    3   6.7   3.7   29.8  85.6    -5.0    224  1.1
  8500   19.0  66.2   315    7    3   6.9   3.8   29.6  85.2    -5.2    202  1.0
  8250   19.5  67.1   315    7    4   6.8   3.8   29.3  84.8    -5.4    179  0.9
  8000   20.0  68.0   315    8    4   6.9   3.8   29.1  84.4    -5.7    157  0.8
  7750   20.5  68.9   320    8    4   6.8   3.7   28.9  84.0    -5.9    135  0.7
  7500   21.0  69.8   320    9    5   7.1   3.9   28.7  83.6    -6.2    113  0.6
  7250   21.4  70.5   325    9    5   3.9   2.1   28.4  83.2    -6.5     92  0.5
  7000   21.5  70.7   325   10    5   0.9   0.5   27.8  82.0    -7.1     81  0.4
  6750   21.7  71.1   315   10    5   2.7   1.5   27.2  80.9    -7.7     70  0.4
  6500   21.8  71.2   305   10    5  -1.7  -0.9   26.6  79.8    -8.3     59  0.3
  6250   21.3  70.3   295   10    5  -8.1  -4.4   25.4  77.7    -9.6     66  0.3
  6000   20.8  69.4   285   11    6  -2.1  -1.2   24.2  75.6   -10.8     74  0.4
  5750   20.9  69.6   280    8    4   4.1   2.3   23.6  74.5   -11.5     63  0.3
  5500   20.6  69.1   265    6    3 -12.9  -7.1   22.8  73.0   -12.5     64  0.3

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

           07/25/2015 at 0900 MDT          |       07/25/2015 at 1200 MDT
                                           |
K index... +24.3  LI... +0.3               | K index... +21.3  LI... +1.1
CAPE... +28.4  CIN... -88.4                | CAPE... +4.9  CIN... -6.1
                                           |
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 -67.1 -88.8  255  31 16   1.1   0.6 | -66.3 -87.3  245  32 16   1.8   1.0
 45000 -62.1 -79.8  255  46 24   7.6   4.2 | -60.5 -76.9  255  45 23   7.0   3.8
 40000 -50.3 -58.5  255  51 26   7.3   4.0 | -50.0 -58.0  255  52 27   7.2   4.0
 38000 -45.9 -50.6  255  48 24   7.3   4.0 | -45.6 -50.1  250  50 26   7.2   4.0
 36000 -41.5 -42.7  250  44 22   7.6   4.2 | -41.3 -42.3  250  48 25   7.7   4.2
 34000 -36.8 -34.2  250  43 22   7.8   4.3 | -36.5 -33.7  250  46 24   8.1   4.5
 32000 -32.1 -25.8  245  42 22   8.3   4.6 | -31.6 -24.9  250  44 22   8.4   4.6
 30000 -27.8 -18.0  245  39 20   7.1   3.9 | -27.2 -17.0  245  41 21   6.4   3.5
 29000 -25.2 -13.4  250  38 19   7.1   3.9 | -25.3 -13.5  245  39 20   6.4   3.5
 28000 -23.1  -9.6  250  36 19   7.1   3.9 | -23.4 -10.1  245  37 19   6.8   3.7
 27000 -20.9  -5.6  250  33 17   7.1   3.9 | -21.3  -6.3  250  34 18   6.8   3.7
 26000 -18.8  -1.8  250  31 16   7.1   3.9 | -19.2  -2.6  250  31 16   6.8   3.7
 25000 -16.6   2.1  255  28 15   6.8   3.7 | -17.2   1.0  255  28 15   7.0   3.8
 24000 -14.6   5.7  255  25 13   6.6   3.6 | -15.1   4.8  255  27 14   7.1   3.9
 23000 -12.7   9.1  255  22 11   6.6   3.6 | -12.9   8.8  260  25 13   7.1   3.9
 22000 -10.7  12.7  260  19 10   7.1   3.9 | -10.8  12.6  260  23 12   7.3   4.0
 21000  -8.5  16.7  260  17  9   7.4   4.0 |  -8.6  16.5  265  22 11   7.4   4.1
 20000  -6.3  20.7  255  16  8   7.4   4.1 |  -6.4  20.5  265  21 11   7.4   4.1
 19500  -5.2  22.6  255  15  8   7.3   4.0 |  -5.3  22.5  265  20 10   7.3   4.0
 19000  -4.4  24.1  255  14  7   4.9   2.7 |  -4.3  24.3  265  19 10   6.1   3.3
 18500  -3.6  25.5  250  13  7   5.3   2.9 |  -3.4  25.9  265  18  9   6.2   3.4
 18000  -2.9  26.8  245  13  6   4.9   2.7 |  -2.5  27.5  265  17  8   5.3   2.9
 17500  -2.3  27.9  250  11  6   4.8   2.6 |  -1.8  28.8  265  15  8   5.0   2.7
 17000  -1.7  28.9  250  10  5   5.0   2.7 |  -1.1  30.0  270  14  7   5.1   2.8
 16500  -1.0  30.2  250   9  5   5.1   2.8 |  -0.4  31.3  270  13  7   5.6   3.1
 16000  -0.4  31.3  260   7  4   5.1   2.8 |   0.7  33.3  270  11  6   6.0   3.3
 15500   1.0  33.8  275   4  2   8.5   4.6 |   1.4  34.5  275   9  5   5.8   3.2
 15000   2.2  36.0  320   2  1   8.4   4.6 |   2.2  36.0  280   7  4   5.7   3.2
 14500   3.3  37.9  030   3  2   7.6   4.2 |   3.2  37.8  285   4  2   9.0   4.9
 14000   4.4  39.9  040   6  3   7.7   4.2 |   4.4  39.9  320   2  1   8.8   4.8
 13500   5.5  41.9  045   8  4   8.4   4.6 |   5.7  42.3  035   2  1   8.8   4.8
 13000   6.9  44.4  040  10  5   8.5   4.7 |   7.1  44.8  035   3  2   8.8   4.8
 12500   8.2  46.8  035  11  6   9.1   5.0 |   8.5  47.3  030   5  2   8.7   4.8
 12000   9.6  49.3  025  12  6   9.4   5.2 |   9.8  49.6  015   5  3   8.7   4.7
 11500  11.0  51.8  020  13  7   9.0   4.9 |  11.1  52.0  360   6  3   8.5   4.7
 11000  12.3  54.1  010  13  7   8.2   4.5 |  12.3  54.1  350   7  4   8.1   4.5
 10500  13.6  56.5  360  13  7   4.0   2.2 |  13.5  56.3  340   8  4   4.6   2.5
 10250  13.7  56.7  360  13  7   5.2   2.8 |  13.7  56.7  340   8  4   6.1   3.4
 10000  14.4  57.9  355  13  7  11.6   6.4 |  14.5  58.1  340   8  4  11.9   6.5
  9750  15.2  59.4  350  12  6  10.5   5.8 |  15.2  59.4  340   8  4  10.9   6.0
  9500  15.9  60.6  345  12  6   8.5   4.7 |  16.0  60.8  340   9  4   9.4   5.2
  9250  16.4  61.5  345  12  6   6.5   3.6 |  16.6  61.9  335   8  4   8.3   4.6
  9000  17.0  62.6  340  12  6   8.8   4.8 |  17.3  63.1  335   8  4  10.6   5.8
  8750  17.7  63.9  335  11  6   9.6   5.2 |  18.1  64.6  335   8  4  11.1   6.1
  8500  18.3  64.9  335  11  6   8.7   4.8 |  18.8  65.8  330   8  4  10.1   5.6
  8250  19.0  66.2  330  11  5   8.2   4.5 |  19.5  67.1  330   8  4   9.3   5.1
  8000  19.6  67.3  330  10  5   8.4   4.6 |  20.2  68.4  330   8  4  10.0   5.5
  7750  20.2  68.4  325  10  5   8.5   4.7 |  21.0  69.8  330   8  4  10.4   5.7
  7500  20.8  69.4  325  10  5   8.8   4.8 |  21.8  71.2  330   8  4  10.2   5.6
  7250  21.5  70.7  325  11  6   8.8   4.8 |  22.5  72.5  330   8  4  10.2   5.6
  7000  22.1  71.8  320  12  6   9.4   5.2 |  23.3  73.9  330   8  4   9.9   5.4
  6750  22.8  73.0  320  13  7   7.7   4.2 |  24.0  75.2  330   8  4   9.9   5.4
  6500  23.1  73.6  320  13  7   3.5   1.9 |  24.8  76.6  330   8  4  10.6   5.8
  6250  23.2  73.8  315  12  6   3.9   2.1 |  25.6  78.1  330   8  4  11.4   6.2
  6000  23.4  74.1  310  11  6   0.3   0.1 |  26.4  79.5  330   7  4   9.4   5.2
  5750  23.2  73.8  295   9  5   4.6   2.5 |  27.1  80.8  325   7  4  14.4   7.9
  5500  24.2  75.6  295   8  4  23.2  12.7 |  28.7  83.7  325   7  4  28.0  15.3

           07/25/2015 at 1500 MDT          |       07/25/2015 at 1800 MDT
                                           |
K index... +23.1  LI... +0.4               | K index... +26.6  LI... -1.6
CAPE... +4.6  CIN... -5.4                  | CAPE... +64.6  CIN... -47.0
                                           |
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 -66.4 -87.5  245  35 18   1.7   1.0 | -67.0 -88.6  245  36 18   1.5   0.8
 45000 -61.0 -77.8  245  46 24   7.0   3.9 | -61.5 -78.7  250  49 25   7.6   4.2
 40000 -49.9 -57.8  250  54 28   7.2   4.0 | -49.7 -57.5  250  57 29   7.2   4.0
 38000 -45.6 -50.1  250  53 27   7.2   4.0 | -45.4 -49.7  250  54 28   7.2   4.0
 36000 -41.2 -42.2  250  51 26   7.8   4.3 | -41.0 -41.8  250  52 27   7.9   4.3
 34000 -36.3 -33.3  250  49 25   8.2   4.5 | -36.1 -33.0  250  49 25   8.3   4.6
 32000 -31.3 -24.3  250  46 24   8.5   4.6 | -31.1 -24.0  250  47 24   8.5   4.7
 30000 -27.2 -17.0  250  44 23   6.0   3.3 | -27.1 -16.8  255  44 22   6.3   3.5
 29000 -25.4 -13.7  250  43 22   6.0   3.3 | -24.8 -12.6  255  42 22   6.3   3.5
 28000 -23.5 -10.3  250  41 21   6.8   3.8 | -22.9  -9.2  255  40 21   6.4   3.5
 27000 -21.5  -6.7  250  37 19   6.8   3.7 | -21.0  -5.8  260  38 19   6.4   3.5
 26000 -19.4  -2.9  255  34 17   6.8   3.7 | -19.1  -2.4  260  35 18   6.4   3.5
 25000 -17.3   0.9  255  31 16   7.1   3.9 | -17.1   1.2  265  33 17   6.8   3.7
 24000 -15.2   4.6  260  29 15   7.2   4.0 | -15.0   5.0  265  33 17   7.1   3.9
 23000 -13.0   8.6  260  28 15   7.2   4.0 | -12.9   8.8  270  32 17   7.1   3.9
 22000 -10.9  12.4  265  27 14   6.9   3.8 | -10.8  12.6  270  32 16   5.7   3.1
 21000  -8.8  16.2  265  27 14   6.7   3.7 |  -9.4  15.1  270  30 16   5.1   2.8
 20000  -6.8  19.8  270  26 13   6.7   3.7 |  -7.9  17.8  275  29 15   5.4   2.9
 19500  -5.8  21.6  270  26 13   6.7   3.6 |  -7.2  19.0  275  28 15   5.7   3.1
 19000  -4.9  23.2  275  25 13   6.0   3.3 |  -6.3  20.7  275  27 14   7.5   4.1
 18500  -4.1  24.6  275  25 13   6.2   3.4 |  -5.3  22.5  275  25 13   7.5   4.1
 18000  -3.2  26.2  280  25 13   6.8   3.7 |  -4.3  24.3  275  23 12   8.4   4.6
 17500  -2.2  28.0  280  24 12   7.1   3.9 |  -3.0  26.6  280  21 11   8.7   4.8
 17000  -1.2  29.8  285  23 12   7.2   4.0 |  -1.7  28.9  280  19 10   8.7   4.8
 16500  -0.2  31.6  285  22 11   6.4   3.5 |  -0.5  31.1  285  17  9   8.5   4.7
 16000   0.7  33.3  290  20 11   6.5   3.6 |   0.8  33.4  290  15  8   8.6   4.7
 15500   2.0  35.6  295  17  9   6.8   3.7 |   2.5  36.5  295  11  6   7.5   4.1
 15000   2.9  37.2  300  14  7   6.7   3.7 |   3.6  38.5  300   8  4   7.4   4.1
 14500   4.0  39.2  305  10  5   8.5   4.7 |   4.8  40.6  305   6  3   8.6   4.7
 14000   5.2  41.4  310   7  4   8.3   4.6 |   6.1  43.0  310   3  2   8.6   4.7
 13500   6.4  43.5  315   4  2   8.8   4.8 |   7.3  45.1  310   1  1   8.2   4.5
 13000   7.7  45.9  325   3  1   8.8   4.9 |   8.5  47.3  000   0  0   8.1   4.4
 12500   9.0  48.2  005   1  1   8.9   4.9 |   9.7  49.5  145   1  1   8.6   4.7
 12000  10.3  50.5  015   1  1   8.9   4.9 |  11.1  52.0  145   2  1   8.9   4.9
 11500  11.7  53.1  025   1  1   8.8   4.8 |  12.4  54.3  145   2  1   8.9   4.9
 11000  12.9  55.2  020   1  1   8.6   4.7 |  13.7  56.7  150   2  1   8.6   4.7
 10500  14.2  57.6  015   2  1   5.7   3.1 |  15.0  59.0  155   2  1   4.9   2.7
 10250  14.5  58.1  015   2  1   7.6   4.2 |  15.2  59.4  155   2  1   6.3   3.5
 10000  15.4  59.7  015   2  1  12.6   6.9 |  16.0  60.8  165   1  1  12.1   6.7
  9750  16.2  61.2  010   2  1  12.1   6.6 |  16.8  62.2  175   1  1  11.2   6.2
  9500  17.1  62.8  010   2  1   9.3   5.1 |  17.6  63.7  205   1  0   9.1   5.0
  9250  17.6  63.7  005   2  1   7.5   4.1 |  18.1  64.6  235   1  0   7.5   4.1
  9000  18.3  64.9  360   2  1  10.8   5.9 |  18.8  65.8  260   1  1   9.8   5.4
  8750  19.2  66.6  360   2  1  11.3   6.2 |  19.5  67.1  270   1  1  10.2   5.6
  8500  20.0  68.0  355   2  1  10.7   5.9 |  20.2  68.4  275   2  1   9.9   5.5
  8250  20.7  69.3  350   2  1  10.4   5.7 |  21.0  69.8  280   2  1   9.7   5.3
  8000  21.5  70.7  345   2  1  10.1   5.5 |  21.7  71.1  280   2  1  10.0   5.5
  7750  22.3  72.1  345   2  1   9.7   5.3 |  22.4  72.3  280   2  1  10.2   5.6
  7500  23.0  73.4  345   2  1   9.9   5.4 |  23.2  73.8  280   2  1   9.9   5.4
  7250  23.7  74.7  340   2  1  10.1   5.5 |  23.9  75.0  280   3  1   9.8   5.4
  7000  24.5  76.1  340   2  1   9.6   5.3 |  24.7  76.5  285   3  1   9.6   5.3
  6750  25.2  77.4  335   2  1   9.8   5.4 |  25.4  77.7  285   3  1   9.6   5.3
  6500  26.0  78.8  330   2  1  10.8   5.9 |  26.1  79.0  280   3  2  10.2   5.6
  6250  26.8  80.2  330   2  1  12.0   6.6 |  26.9  80.4  285   3  2  10.8   5.9
  6000  27.6  81.7  325   2  1   8.8   4.8 |  27.7  81.9  285   3  2   9.5   5.2
  5750  28.3  82.9  325   2  1  13.5   7.4 |  28.4  83.1  285   3  2  11.1   6.1
  5500  29.9  85.8  325   2  1  30.2  16.6 |  29.4  84.9  285   4  2  17.8   9.7
________________________________________________________________________________

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


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.