Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14

000
UXUS97 KBOU 241319
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0719 MDT Wednesday, May 24, 2017

This forecast is for Wednesday, May 24, 2017:

If the trigger temperature of 69.2 F/20.7 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 876 ft/min (4.4 m/s)
   Maximum height of thermals.................. 15958 ft MSL (10673 ft AGL)

Forecast maximum temperature................... 82.0 F/28.2 C
Time of trigger temperature.................... 1015 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................. 13329 ft MSL (8043 ft AGL)
Thermal soaring outlook for Thursday 05/25..... Fair

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... Little change
Height of stable layer (12-18K ft MSL)......... 16830 ft MSL (11545 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 18304 ft MSL (13019 ft AGL)
Wave soaring outlook for Thursday 05/25........ Poor

Remarks...

Sunrise/Sunset.................... 05:37:19 / 20:15:25 MDT
Total possible sunshine........... 14 hr 38 min 6 sec (878 min 6 sec)
Altitude of sun at 12:56:22 MDT... 71.12 degrees

Upper air data from rawinsonde observation taken on 05/24/2017 at 0600 MDT

Freezing level.................. 13540 ft MSL (8255 ft AGL)
Convective condensation level... 18180 ft MSL (12895 ft AGL)
Lifted condensation level....... 17505 ft MSL (12219 ft AGL)
Lifted index.................... +0.2
K index......................... +10.9

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -71.8 -97.2   320   54   28   2.8   1.5   76.4 169.5    28.0      M    M
 45000  -65.0 -85.0   345   67   34   5.9   3.2   63.4 146.2    22.1      M    M
 40000  -56.4 -69.5   350   75   39   4.7   2.6   52.8 127.1    16.7      M    M
 38000  -53.3 -63.9   350   75   39   6.1   3.3   48.8 119.8    14.4      M    M
 36000  -48.2 -54.8   350   75   39   8.6   4.7   47.6 117.6    13.9      M    M
 34000  -43.7 -46.7   350   72   37   6.3   3.5   45.7 114.3    12.9      M    M
 32000  -39.9 -39.8   345   67   34   6.3   3.4   43.0 109.3    11.2      M    M
 30000  -35.1 -31.2   345   61   32   8.7   4.8   41.7 107.0    10.5      M    M
 29000  -32.5 -26.5   345   58   30   8.6   4.7   41.1 106.0    10.2      M    M
 28000  -29.2 -20.6   345   53   27   8.6   4.7   40.5 105.0     9.9      M    M
 27000  -26.6 -15.9   340   50   26   6.4   3.5   40.2 104.4     9.8      M    M
 26000  -25.7 -14.3   340   46   24   5.0   2.7   37.7  99.9     7.9      M    M
 25000  -23.4 -10.1   340   43   22   8.2   4.5   37.0  98.7     7.4      M    M
 24000  -21.4  -6.5   335   43   22   0.8   0.4   35.9  96.6     6.6      M    M
 23000  -20.1  -4.2   335   44   22   9.3   5.1   33.9  93.1     5.0      M    M
 22000  -17.4   0.7   335   44   23   8.9   4.9   33.6  92.5     4.8      M    M
 21000  -14.9   5.2   335   45   23   5.7   3.2   33.2  91.7     4.5      M    M
 20000  -13.4   7.9   335   45   23   7.2   3.9   31.8  89.2     3.1      M    M
 19500  -12.3   9.9   335   45   23   7.3   4.0   31.3  88.4     2.8      M    M
 19000  -11.2  11.8   335   44   23   7.3   4.0   30.9  87.7     2.4      M    M
 18500   -9.9  14.2   335   45   23   9.0   4.9   30.7  87.2     2.2      M    M
 18000   -8.6  16.5   335   47   24   8.8   4.8   30.5  86.9     2.1      M    M
 17500   -7.3  18.9   335   45   23   8.7   4.8   30.3  86.6     2.0      M    M
 17000   -6.1  21.0   335   43   22   5.4   3.0   30.1  86.2     1.8      M    M
 16500   -5.7  21.7   340   41   21   4.4   2.4   28.9  84.1     0.6      M    M
 16000   -4.8  23.4   340   38   20   6.5   3.6   28.3  83.0     0.1      M    M
 15500   -3.8  25.2   340   37   19   6.5   3.6   27.8  82.0    -0.4    843  4.3
 15000   -2.8  27.0   340   35   18   6.5   3.6   27.2  81.0    -0.8    799  4.1
 14500   -1.8  28.8   335   34   17   6.6   3.6   26.7  80.1    -1.3    755  3.8
 14000   -0.5  31.1   335   32   16   5.5   3.0   25.8  78.4    -2.2    694  3.5
 13500    0.2  32.4   335   31   16   5.5   3.0   25.0  77.1    -2.9    656  3.3
 13000    1.0  33.8   335   31   16   5.5   3.0   24.3  75.8    -3.6    617  3.1
 12500    1.8  35.2   335   30   16   5.5   3.0   23.7  74.6    -4.3    579  2.9
 12000    2.6  36.7   335   30   15   5.2   2.9   23.0  73.5    -5.0    541  2.7
 11500    3.6  38.5   330   28   14   8.9   4.9   22.6  72.7    -5.4    496  2.5
 11000    4.9  40.8   330   26   13   8.6   4.7   22.4  72.3    -5.7    443  2.2
 10500    6.2  43.2   325   24   12   8.6   4.7   22.2  72.0    -5.9    390  2.0
 10250    6.8  44.2   320   23   12   8.4   4.6   22.1  71.8    -6.0    363  1.8
 10000    7.4  45.3   320   23   12   7.1   3.9   22.0  71.6    -6.1    338  1.7
  9750    7.9  46.2   315   23   12   6.5   3.5   21.8  71.2    -6.4    316  1.6
  9500    8.4  47.1   315   22   12   6.6   3.6   21.5  70.7    -6.6    294  1.5
  9250    8.8  47.8   310   22   11   6.6   3.6   21.3  70.3    -6.9    272  1.4
  9000    9.3  48.7   310   22   11   6.6   3.6   21.0  69.9    -7.1    250  1.3
  8750    9.8  49.6   305   21   11   6.6   3.6   20.8  69.4    -7.4    228  1.2
  8500   10.3  50.5   305   21   11   6.6   3.6   20.5  69.0    -7.6    206  1.0
  8250   10.8  51.4   300   20   11   6.6   3.6   20.3  68.6    -7.9    184  0.9
  8000   11.3  52.3   300   20   10   6.6   3.6   20.1  68.1    -8.2    162  0.8
  7750   11.8  53.2   300   20   10   6.7   3.7   19.8  67.7    -8.4    140  0.7
  7500   12.2  54.0   300   19   10   6.2   3.4   19.6  67.2    -8.7    119  0.6
  7250   12.7  54.9   295   19   10   8.1   4.5   19.3  66.8    -9.0     97  0.5
  7000   13.2  55.8   295   19   10  -0.8  -0.5   19.1  66.3    -9.3     76  0.4
  6750   12.6  54.7   290   15    8  -9.5  -5.2   17.7  63.9   -10.6     86  0.4
  6500   12.0  53.6   280   10    5  -6.8  -3.7   16.4  61.5   -12.0     96  0.5
  6250   11.4  52.5   260    7    3  -8.9  -4.9   15.1  59.2   -13.3    107  0.5
  6000   10.8  51.4   215    5    3  -3.2  -1.8   13.8  56.8   -14.6    117  0.6
  5750   10.2  50.4   195    4    2 -23.7 -13.0   12.5  54.5   -16.0    127  0.6
  5500    6.9  44.4   165    4    2 -60.8 -33.3    8.4  47.1   -20.1    220  1.1

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

           05/24/2017 at 0900 MDT          |       05/24/2017 at 1200 MDT
                                           |
CAPE...     0.0    LI...       +3.5        | CAPE...    +1.0    LI...       +0.6
CINH...     0.0    K Index... +11.1        | CINH...    -7.5    K Index...  +9.0
                                           |
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  340  20 10   0.1   0.0 | -66.3 -87.3  325  14  7  -0.5  -0.3
 45000 -65.2 -85.4  335  27 14   5.5   3.0 | -65.3 -85.5  325  23 12   5.9   3.3
 40000 -56.5 -69.7  335  31 16   6.1   3.4 | -56.4 -69.5  325  25 13   6.5   3.6
 38000 -52.3 -62.1  335  31 16   7.0   3.8 | -52.1 -61.8  325  24 12   7.3   4.0
 36000 -48.2 -54.8  335  30 16   7.0   3.8 | -47.7 -53.9  320  23 12   7.3   4.0
 34000 -43.7 -46.7  335  29 15   7.9   4.3 | -43.0 -45.4  320  23 12   8.2   4.5
 32000 -38.9 -38.0  335  27 14   7.9   4.3 | -38.1 -36.6  315  23 12   8.2   4.5
 30000 -33.6 -28.5  330  25 13   8.0   4.4 | -32.7 -26.9  310  23 12   8.0   4.4
 29000 -31.2 -24.2  325  25 13   8.0   4.4 | -30.3 -22.5  305  23 12   8.0   4.4
 28000 -28.8 -19.8  325  24 12   8.0   4.4 | -27.9 -18.2  305  23 12   8.0   4.4
 27000 -26.5 -15.7  325  23 12   7.3   4.0 | -25.7 -14.3  305  22 12   7.2   3.9
 26000 -24.4 -11.9  320  22 12   7.3   4.0 | -23.5 -10.3  305  22 11   7.2   3.9
 25000 -22.2  -8.0  320  22 11   7.3   4.0 | -21.4  -6.5  305  21 11   7.2   3.9
 24000 -20.1  -4.2  320  21 11   6.7   3.7 | -19.4  -2.9  300  20 11   5.1   2.8
 23000 -18.1  -0.6  320  20 10   6.7   3.7 | -17.9  -0.2  305  19 10   5.3   2.9
 22000 -16.1   3.0  320  20 10   6.7   3.7 | -16.3   2.7  305  18  9   5.3   2.9
 21000 -14.1   6.6  320  19 10   6.3   3.5 | -14.7   5.5  305  17  9   5.8   3.2
 20000 -12.3   9.9  320  18  9   6.3   3.5 | -13.0   8.6  305  15  8   5.8   3.2
 19500 -11.3  11.7  320  18  9   6.3   3.5 | -12.1  10.2  305  15  8   5.8   3.2
 19000 -10.4  13.3  325  18  9   6.4   3.5 | -11.3  11.7  305  14  7   5.6   3.1
 18500  -9.5  14.9  325  17  9   6.4   3.5 | -10.3  13.5  305  14  7   7.3   4.0
 18000  -8.5  16.7  325  17  9   6.4   3.5 |  -9.3  15.3  310  13  7   7.2   4.0
 17500  -7.6  18.3  325  17  9   6.5   3.6 |  -8.2  17.2  310  12  6   7.4   4.1
 17000  -6.6  20.1  325  16  8   6.5   3.6 |  -6.5  20.3  310  12  6   7.7   4.2
 16500  -5.2  22.6  330  16  8   6.7   3.7 |  -5.4  22.3  310  11  6   7.8   4.3
 16000  -4.2  24.4  330  16  8   6.8   3.7 |  -4.2  24.4  310  11  5   7.9   4.3
 15500  -3.2  26.2  330  15  8   6.8   3.7 |  -3.0  26.6  310  10  5   7.9   4.3
 15000  -2.2  28.0  330  15  8   6.9   3.8 |  -1.8  28.8  310  10  5   8.1   4.4
 14500  -1.2  29.8  335  14  7   6.9   3.8 |  -0.6  30.9  310   9  5   8.1   4.5
 14000  -0.1  31.8  335  14  7   7.5   4.1 |   0.5  32.9  310   9  5   7.7   4.2
 13500   1.0  33.8  335  14  7   7.5   4.1 |   1.7  35.1  310   9  5   7.8   4.3
 13000   2.1  35.8  335  13  7   7.8   4.3 |   2.8  37.0  305   9  4   7.7   4.2
 12500   3.2  37.8  335  13  7   7.9   4.3 |   3.9  39.0  305   8  4   7.7   4.2
 12000   4.4  39.9  335  12  6   7.5   4.1 |   5.0  41.0  300   8  4   7.7   4.2
 11500   5.5  41.9  330  12  6   7.3   4.0 |   6.1  43.0  295   8  4   7.6   4.2
 11000   6.5  43.7  330  12  6   6.9   3.8 |   7.2  45.0  290   8  4   7.9   4.3
 10500   7.5  45.5  325  11  6   6.2   3.4 |   8.4  47.1  290   8  4   7.8   4.3
 10250   7.9  46.2  325  11  6   8.2   4.5 |   9.0  48.2  290   8  4   9.7   5.3
 10000   8.6  47.5  320  11  6   8.3   4.6 |   9.8  49.6  290   8  4   9.5   5.2
  9750   9.1  48.4  320  11  6   6.4   3.5 |  10.3  50.5  290   8  4   7.7   4.2
  9500   9.6  49.3  315  11  6   6.9   3.8 |  10.9  51.6  285   8  4   8.2   4.5
  9250  10.1  50.2  315  12  6   6.9   3.8 |  11.5  52.7  285   8  4   8.2   4.5
  9000  10.6  51.1  310  11  6   6.2   3.4 |  12.1  53.8  290   9  5   8.3   4.6
  8750  11.0  51.8  310  11  6   5.6   3.0 |  12.7  54.9  285   8  4   8.2   4.5
  8500  11.4  52.5  305  11  6   5.9   3.3 |  13.3  55.9  285   8  4   8.4   4.6
  8250  11.8  53.2  305  11  6   5.1   2.8 |  13.9  57.0  285   7  4   7.7   4.2
  8000  12.1  53.8  305  11  6   4.0   2.2 |  14.4  57.9  285   6  3   8.3   4.6
  7750  12.4  54.3  300  10  5   4.6   2.5 |  15.1  59.2  285   6  3  10.0   5.5
  7500  12.8  55.0  300   9  5   5.3   2.9 |  15.8  60.4  285   6  3  10.1   5.5
  7250  13.1  55.6  295   8  4   4.5   2.5 |  16.6  61.9  285   5  3   9.8   5.4
  7000  13.4  56.1  295   7  4   3.7   2.0 |  17.3  63.1  285   5  3   9.5   5.2
  6750  13.7  56.7  295   6  3   4.7   2.6 |  18.0  64.4  285   5  2  10.1   5.6
  6500  14.1  57.4  285   5  2   5.4   3.0 |  18.8  65.8  285   5  2  10.5   5.7
  6250  14.5  58.1  275   4  2   4.5   2.5 |  19.6  67.3  285   4  2  10.6   5.8
  6000  14.8  58.6  260   3  1   3.9   2.1 |  20.4  68.7  285   4  2  11.4   6.2
  5750  15.1  59.2  230   2  1   4.8   2.6 |  21.2  70.2  285   4  2   9.2   5.1
  5500  15.5  59.9  220   2  1  10.5   5.8 |  21.9  71.4  285   4  2  13.5   7.4

           05/24/2017 at 1500 MDT          |       05/24/2017 at 1800 MDT
                                           |
CAPE...   +20.4    LI...       +0.1        | CAPE...  +111.0    LI...       -0.0
CINH...   -33.9    K Index... +14.7        | CINH...   -38.4    K Index... +17.5
                                           |
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 -66.8 -88.2  300  11  6  -0.2  -0.1 | -66.5 -87.7  255  10  5   0.5   0.3
 45000 -65.3 -85.5  305  16  8   6.6   3.6 | -64.1 -83.4  250  13  7   6.3   3.5
 40000 -55.4 -67.7  300  22 11   6.8   3.7 | -54.6 -66.3  270  23 12   6.3   3.5
 38000 -51.1 -60.0  295  22 11   7.1   3.9 | -50.9 -59.6  270  24 12   6.3   3.4
 36000 -46.9 -52.4  295  21 11   7.1   3.9 | -47.1 -52.8  265  25 13   6.3   3.4
 34000 -42.4 -44.3  295  21 11   7.8   4.3 | -43.1 -45.6  265  25 13   7.1   3.9
 32000 -37.1 -34.8  290  22 11   7.8   4.3 | -38.3 -36.9  270  23 12   7.1   3.9
 30000 -32.5 -26.5  290  22 11   7.4   4.1 | -34.0 -29.2  270  22 11   7.2   3.9
 29000 -30.3 -22.5  290  22 11   7.4   4.1 | -31.8 -25.2  275  21 11   7.2   3.9
 28000 -28.1 -18.6  290  22 11   7.4   4.1 | -29.7 -21.5  275  20 10   7.2   4.0
 27000 -26.0 -14.8  290  21 11   6.4   3.5 | -27.6 -17.7  275  19 10   7.0   3.9
 26000 -24.1 -11.4  290  21 11   6.3   3.5 | -25.5 -13.9  280  18  9   7.0   3.8
 25000 -22.3  -8.1  290  20 10   6.3   3.5 | -23.4 -10.1  285  16  8   7.0   3.9
 24000 -20.4  -4.7  290  19 10   5.7   3.1 | -21.3  -6.3  285  15  8   7.1   3.9
 23000 -18.7  -1.7  290  18  9   5.8   3.2 | -19.2  -2.6  290  15  7   7.1   3.9
 22000 -17.0   1.4  290  17  9   5.8   3.2 | -17.1   1.2  290  14  7   7.1   3.9
 21000 -15.1   4.8  295  16  8   7.2   3.9 | -14.9   5.2  295  13  7   7.4   4.0
 20000 -13.0   8.6  295  15  8   7.1   3.9 | -12.8   9.0  295  13  7   7.4   4.0
 19500 -12.0  10.4  295  15  7   7.1   3.9 | -11.7  10.9  295  13  6   7.4   4.0
 19000 -10.9  12.4  295  14  7   7.1   3.9 | -10.6  12.9  295  12  6   7.4   4.0
 18500  -9.8  14.4  295  14  7   7.9   4.4 |  -9.5  14.9  295  12  6   7.5   4.1
 18000  -8.6  16.5  295  13  7   7.9   4.3 |  -8.4  16.9  295  12  6   7.5   4.1
 17500  -6.9  19.6  295  13  6   7.6   4.2 |  -6.7  19.9  295  12  6   7.5   4.1
 17000  -5.8  21.6  295  12  6   7.7   4.2 |  -5.6  21.9  290  12  6   7.6   4.1
 16500  -4.6  23.7  295  12  6   7.7   4.2 |  -4.5  23.9  290  12  6   7.7   4.2
 16000  -3.5  25.7  295  12  6   7.7   4.2 |  -3.4  25.9  290  12  6   7.7   4.3
 15500  -2.4  27.7  295  11  6   7.7   4.2 |  -2.3  27.9  285  12  6   7.8   4.3
 15000  -1.3  29.7  295  11  6   7.7   4.2 |  -1.1  30.0  285  12  6   8.1   4.4
 14500  -0.1  31.8  290  10  5   7.7   4.2 |   0.1  32.2  285  12  6   8.0   4.4
 14000   1.0  33.8  290  10  5   8.1   4.4 |   1.3  34.3  280  12  6   8.7   4.8
 13500   2.2  36.0  290  10  5   8.1   4.4 |   2.5  36.5  280  12  6   8.7   4.8
 13000   3.4  38.1  290   9  5   8.6   4.7 |   3.8  38.8  280  12  6   8.9   4.9
 12500   4.7  40.5  290   9  5   8.7   4.8 |   5.1  41.2  280  12  6   9.0   4.9
 12000   6.0  42.8  290   9  5   8.7   4.8 |   6.4  43.5  280  12  6   9.1   5.0
 11500   7.2  45.0  290   9  5   8.7   4.8 |   7.7  45.9  275  11  6   9.1   5.0
 11000   8.5  47.3  290   9  5   8.4   4.6 |   9.1  48.4  275  10  5   8.7   4.8
 10500   9.6  49.3  290   8  4   8.2   4.5 |  10.3  50.5  275   9  5   8.5   4.7
 10250  10.3  50.5  290   8  4  10.3   5.6 |  11.0  51.8  275   9  5  11.0   6.0
 10000  11.1  52.0  290   7  4  11.0   6.0 |  11.9  53.4  275   9  5  11.5   6.3
  9750  11.8  53.2  290   7  4  10.0   5.5 |  12.6  54.7  275   9  5  10.2   5.6
  9500  12.6  54.7  290   7  3  10.6   5.8 |  13.4  56.1  275   8  4  10.9   6.0
  9250  13.3  55.9  290   6  3   9.3   5.1 |  14.2  57.6  275   8  4   8.9   4.9
  9000  14.0  57.2  290   7  3   9.0   4.9 |  14.8  58.6  275   8  4   8.1   4.5
  8750  14.7  58.5  290   7  3  10.0   5.5 |  15.5  59.9  275   8  4   9.7   5.3
  8500  15.5  59.9  290   7  3  10.0   5.5 |  16.2  61.2  270   8  4   9.5   5.2
  8250  16.2  61.2  290   6  3   9.3   5.1 |  16.9  62.4  270   8  4   9.5   5.2
  8000  16.9  62.4  290   6  3   9.3   5.1 |  17.6  63.7  275   7  4   9.7   5.3
  7750  17.6  63.7  290   6  3  10.2   5.6 |  18.3  64.9  270   7  4   9.8   5.4
  7500  18.3  64.9  290   6  3  10.3   5.6 |  19.1  66.4  270   7  4   9.9   5.4
  7250  19.1  66.4  290   6  3   9.6   5.3 |  19.8  67.6  270   7  4   9.6   5.3
  7000  19.8  67.6  290   6  3   9.0   4.9 |  20.5  68.9  270   7  3   9.2   5.0
  6750  20.5  68.9  290   6  3  10.3   5.7 |  21.2  70.2  270   7  3   9.9   5.4
  6500  21.3  70.3  290   6  3  11.3   6.2 |  22.0  71.6  270   6  3  10.5   5.8
  6250  22.1  71.8  290   5  3  10.7   5.9 |  22.7  72.9  270   6  3  10.3   5.6
  6000  22.9  73.2  295   5  3  10.8   5.9 |  23.5  74.3  270   6  3  10.3   5.7
  5750  23.7  74.7  295   5  3   9.3   5.1 |  24.2  75.6  270   6  3   9.6   5.3
  5500  24.5  76.1  295   5  2  14.3   7.9 |  24.9  76.8  270   5  3  10.9   6.0
________________________________________________________________________________

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.

CINH (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.