Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12
000
UXUS97 KPUB 241029
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0428 MDT Wednesday, June 24, 2015

This forecast is for Wednesday, June 24, 2015:

If the trigger temperature of 81.5 F/27.5 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1140 ft/min (5.8 m/s)
   Maximum height of thermals.................. 19753 ft MSL (12995 ft AGL)

Forecast maximum temperature................... 85.0 F/29.9 C
Time of trigger temperature.................... 1115 MDT
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................. 8400 ft MSL (1642 ft AGL)
Thermal soaring outlook for Thursday 06/25..... Excellent

Wave Soaring Index............................. Not available

Remarks...

Sunrise/Sunset.................... 05:34:37 / 20:28:09 MDT
Total possible sunshine........... 14 hr 53 min 32 sec (893 min 32 sec)
Altitude of sun at 13:01:28 MDT... 74.42 degrees

Upper air data from numerical model forecast valid on 06/24/2015 at 0600 MDT

Freezing level.................. 16749 ft MSL (9991 ft AGL)
Convective condensation level... 17768 ft MSL (11010 ft AGL)
Lifted condensation level....... 17658 ft MSL (10901 ft AGL)
Lifted index.................... -4.1
K index......................... +25.3

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  -66.2 -87.2   290   30   15   2.5   1.4      M     M       M      M    M
 45000  -61.0 -77.8   275   40   21   4.9   2.7      M     M       M      M    M
 40000  -53.4 -64.1   265   42   21   6.2   3.4      M     M       M      M    M
 38000  -49.6 -57.3   265   38   20   6.3   3.4      M     M       M      M    M
 36000  -45.9 -50.6   270   35   18   6.3   3.5      M     M       M      M    M
 34000  -40.8 -41.4   265   32   16   8.6   4.7      M     M       M      M    M
 32000  -35.0 -31.0   255   29   15   9.0   5.0      M     M       M      M    M
 30000  -30.2 -22.4   255   25   13   8.1   4.5   39.1 102.5     7.5      M    M
 29000  -27.8 -18.0   255   23   12   8.2   4.5   38.6 101.5     7.1      M    M
 28000  -25.5 -13.9   255   21   11   5.7   3.1   37.9 100.1     6.6      M    M
 27000  -23.7 -10.7   260   19   10   6.0   3.3   36.3  97.4     5.4      M    M
 26000  -22.0  -7.6   260   17    9   6.0   3.3   34.9  94.9     4.3      M    M
 25000  -20.2  -4.4   265   16    8   6.8   3.8   33.7  92.7     3.3      M    M
 24000  -17.9  -0.2   270   15    8   7.5   4.1   32.8  91.0     2.6      M    M
 23000  -15.7   3.7   275   15    8   7.5   4.1   32.0  89.6     2.0      M    M
 22000  -13.4   7.9   280   15    8   7.8   4.3   31.3  88.4     1.4      M    M
 21000  -11.1  12.0   280   15    8   7.9   4.3   30.6  87.1     0.7      M    M
 20000   -8.8  16.2   280   14    7   8.0   4.4   30.0  86.0     0.2      M    M
 19500   -7.6  18.3   280   14    7   8.2   4.5   29.7  85.5    -0.1   1321  6.7
 19000   -6.3  20.7   280   14    7   9.1   5.0   29.6  85.2    -0.3   1267  6.4
 18500   -5.0  23.0   275   13    7   9.1   5.0   29.5  85.0    -0.4   1213  6.2
 18000   -3.7  25.3   275   12    6   9.2   5.0   29.4  84.8    -0.6   1159  5.9
 17500   -2.3  27.9   270   11    6   9.2   5.1   29.3  84.7    -0.7   1104  5.6
 17000   -1.0  30.2   265   11    5   9.3   5.1   29.2  84.5    -0.8   1049  5.3
 16500    0.4  32.7   265   10    5   9.5   5.2   29.1  84.4    -0.9    992  5.0
 16000    1.8  35.2   265   11    5   9.5   5.2   29.1  84.3    -1.0    936  4.8
 15500    3.9  39.0   265   11    6   9.7   5.3   29.0  84.3    -1.1    850  4.3
 15000    5.3  41.5   260   11    6   9.7   5.3   29.0  84.2    -1.1    793  4.0
 14500    6.7  44.1   260   12    6   9.1   5.0   29.0  84.2    -1.2    736  3.7
 14000    8.1  46.6   260   13    6   9.2   5.0   28.9  84.0    -1.3    680  3.5
 13500    9.5  49.1   260   14    7   9.3   5.1   28.8  83.9    -1.4    625  3.2
 13000   10.8  51.4   260   15    8   9.2   5.0   28.7  83.7    -1.5    569  2.9
 12500   12.2  54.0   255   17    9   9.5   5.2   28.7  83.7    -1.5    512  2.6
 12000   13.5  56.3   255   18    9   9.0   5.0   28.6  83.5    -1.7    457  2.3
 11750   14.2  57.6   255   18    9   8.5   4.7   28.5  83.3    -1.8    430  2.2
 11500   14.9  58.8   255   19   10  10.8   5.9   28.5  83.3    -1.8    403  2.0
 11250   15.7  60.3   255   19   10  10.5   5.8   28.6  83.5    -1.7    370  1.9
 11000   16.4  61.5   255   19   10   8.4   4.6   28.6  83.4    -1.8    343  1.7
 10750   17.0  62.6   255   19   10   8.8   4.8   28.5  83.3    -1.9    316  1.6
 10500   17.7  63.9   255   20   10   9.3   5.1   28.4  83.1    -2.0    289  1.5
 10250   18.4  65.1   255   20   10  10.0   5.5   28.4  83.2    -2.0    260  1.3
 10000   19.1  66.4   250   20   10   8.7   4.8   28.4  83.1    -2.0    232  1.2
  9750   19.7  67.5   250   20   10   8.0   4.4   28.3  82.9    -2.1    206  1.0
  9500   20.3  68.5   250   20   10   8.2   4.5   28.2  82.7    -2.3    181  0.9
  9250   20.9  69.6   250   20   10   8.2   4.5   28.0  82.5    -2.4    155  0.8
  9000   21.5  70.7   250   19   10   8.0   4.4   27.9  82.2    -2.5    130  0.7
  8750   22.1  71.8   250   20   10   9.6   5.3   27.8  82.1    -2.6    104  0.5
  8500   22.8  73.0   250   20   10   4.5   2.5   27.7  81.9    -2.8     78  0.4
  8250   22.8  73.0   250   19   10  -0.7  -0.4   27.0  80.6    -3.5     70  0.4
  8000   22.8  73.0   250   18   10   1.2   0.7   26.3  79.4    -4.2     63  0.3
  7750   22.8  73.0   250   18    9  -1.1  -0.6   25.6  78.1    -5.0     55  0.3
  7500   22.1  71.8   250   17    9 -16.7  -9.1   24.4  76.0    -6.3     67  0.3
  7250   20.2  68.4   255   13    7 -28.3 -15.5   22.2  72.0    -8.6    118  0.6
  7000   18.2  64.8   265   10    5 -19.5 -10.7   20.0  68.0   -10.9    169  0.9
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           06/24/2015 at 0900 MDT          |       06/24/2015 at 1200 MDT
                                           |
K index... +22.1  LI... +271.5             | K index... +27.1  LI... +271.3
CAPE... +511.2  CIN... -40.0               | CAPE... +543.1  CIN... -5.8
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -65.7 -86.3  285  28 14   2.6   1.4 | -65.0 -85.0  275  26 13   2.7   1.5
 45000 -60.8 -77.4  270  41 21   4.6   2.5 | -60.3 -76.5  275  43 22   4.0   2.2
 40000 -53.5 -64.3  265  41 21   6.0   3.3 | -53.9 -65.0  265  44 23   6.3   3.4
 38000 -49.9 -57.8  265  36 19   6.0   3.3 | -50.1 -58.2  265  39 20   6.3   3.5
 36000 -46.3 -51.3  265  31 16   5.9   3.3 | -46.3 -51.3  265  34 17   6.2   3.4
 34000 -41.2 -42.2  265  29 15   8.8   4.8 | -40.7 -41.3  260  31 16   8.6   4.7
 32000 -35.3 -31.5  260  28 14   9.2   5.0 | -35.5 -31.9  255  29 15   9.1   5.0
 30000 -30.4 -22.7  260  26 13   8.0   4.4 | -30.5 -22.9  255  28 14   8.4   4.6
 29000 -28.1 -18.6  260  25 13   8.1   4.4 | -28.0 -18.4  250  27 14   8.4   4.6
 28000 -25.8 -14.4  255  24 12   5.7   3.1 | -25.7 -14.3  250  26 13   5.8   3.2
 27000 -24.0 -11.2  255  21 11   6.0   3.3 | -23.8 -10.8  250  24 13   6.1   3.3
 26000 -22.2  -8.0  250  19 10   6.0   3.3 | -22.0  -7.6  255  23 12   6.1   3.3
 25000 -20.4  -4.7  245  16  8   6.9   3.8 | -20.2  -4.4  255  21 11   6.6   3.6
 24000 -18.1  -0.6  250  15  8   7.6   4.2 | -18.1  -0.6  255  18  9   7.1   3.9
 23000 -15.9   3.4  255  13  7   7.7   4.2 | -16.0   3.2  250  16  8   7.1   3.9
 22000 -13.6   7.5  260  12  6   8.1   4.4 | -13.9   7.0  245  13  7   8.0   4.4
 21000 -11.1  12.0  265  12  6   8.3   4.5 | -11.4  11.5  250  11  6   8.4   4.6
 20000  -8.7  16.3  275  11  6   8.3   4.5 |  -8.9  16.0  255  10  5   8.5   4.7
 19500  -7.5  18.5  275  11  6   8.4   4.6 |  -7.7  18.1  260   9  5   8.6   4.7
 19000  -6.2  20.8  280  11  6   8.7   4.8 |  -6.4  20.5  265   9  5   9.0   4.9
 18500  -5.0  23.0  275  10  5   8.7   4.8 |  -5.1  22.8  265   8  4   9.0   4.9
 18000  -3.7  25.3  280   9  5   9.1   5.0 |  -3.8  25.2  270   8  4   8.9   4.9
 17500  -2.3  27.9  280   9  5   9.2   5.1 |  -2.5  27.5  270   7  4   8.9   4.9
 17000  -1.0  30.2  280   9  5   9.3   5.1 |  -1.2  29.8  270   7  3   9.0   4.9
 16500   0.4  32.7  280   9  4   9.4   5.2 |   0.1  32.2  275   6  3   9.1   5.0
 16000   1.8  35.2  285   9  5   9.4   5.1 |   2.1  35.8  285   6  3   9.3   5.1
 15500   3.9  39.0  285   9  4   9.5   5.2 |   3.5  38.3  295   6  3   9.4   5.2
 15000   5.3  41.5  290   8  4   9.5   5.2 |   4.9  40.8  305   6  3   9.5   5.2
 14500   6.7  44.1  290   8  4   9.6   5.3 |   6.3  43.3  310   7  3   9.5   5.2
 14000   8.1  46.6  295   9  4   9.6   5.3 |   7.7  45.9  320   7  4   9.5   5.2
 13500   9.5  49.1  295   9  5   9.3   5.1 |   9.1  48.4  325   8  4   9.7   5.3
 13000  10.9  51.6  300  10  5   9.3   5.1 |  10.6  51.1  330   8  4   9.7   5.3
 12500  12.3  54.1  300  11  6   9.4   5.2 |  12.0  53.6  330   8  4   9.9   5.5
 12000  13.7  56.7  300  12  6   9.4   5.1 |  13.5  56.3  335   8  4   9.7   5.3
 11750  14.4  57.9  300  12  6   9.3   5.1 |  14.2  57.6  335   8  4   9.6   5.3
 11500  15.1  59.2  300  12  6  10.2   5.6 |  14.9  58.8  335   8  4  11.2   6.1
 11250  15.9  60.6  300  13  6   9.8   5.4 |  15.8  60.4  335   8  4  10.5   5.8
 11000  16.5  61.7  300  13  7   8.7   4.8 |  16.5  61.7  335   8  4   8.8   4.9
 10750  17.2  63.0  300  13  7   8.9   4.9 |  17.2  63.0  335   8  4   9.2   5.0
 10500  17.9  64.2  300  13  7   9.4   5.2 |  17.9  64.2  335   8  4   9.8   5.4
 10250  18.6  65.5  300  14  7  10.0   5.5 |  18.6  65.5  340   8  4  10.4   5.7
 10000  19.3  66.7  300  14  7   8.8   4.8 |  19.4  66.9  340   8  4   9.9   5.4
  9750  19.9  67.8  295  15  7   8.2   4.5 |  20.1  68.2  340   8  4   9.8   5.4
  9500  20.5  68.9  295  15  8   8.4   4.6 |  20.8  69.4  340   8  4   9.6   5.3
  9250  21.2  70.2  295  16  8   8.4   4.6 |  21.5  70.7  340   8  4   9.2   5.1
  9000  21.8  71.2  295  16  8   8.2   4.5 |  22.3  72.1  340   8  4   9.7   5.3
  8750  22.4  72.3  295  17  9   8.0   4.4 |  23.0  73.4  340   8  4  10.6   5.8
  8500  22.9  73.2  290  17  9   6.5   3.6 |  23.8  74.8  340   8  4  10.6   5.8
  8250  23.3  73.9  290  17  9   5.8   3.2 |  24.6  76.3  340   8  4  10.5   5.8
  8000  23.6  74.5  285  16  8   5.3   2.9 |  25.3  77.5  345   8  4  10.1   5.5
  7750  24.0  75.2  285  16  8   8.8   4.8 |  26.1  79.0  345   8  4  11.8   6.5
  7500  24.7  76.5  280  14  7   7.4   4.0 |  27.0  80.6  345   7  4  11.9   6.5
  7250  24.8  76.6  280  12  6   1.8   1.0 |  27.8  82.0  345   7  4   9.7   5.3
  7000  24.9  76.8  280  10  5   6.6   3.6 |  28.5  83.3  345   7  4  11.6   6.3
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           06/24/2015 at 1500 MDT          |       06/24/2015 at 1800 MDT
                                           |
K index... +29.4  LI... +272.0             | K index... +26.6  LI... +271.5
CAPE... +127.8  CIN... -3.1                | CAPE... +286.5  CIN... -63.0
                                           |
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 -65.6 -86.1  270  30 16   3.1   1.7 | -65.2 -85.4  280  31 16   2.9   1.6
 45000 -60.8 -77.4  270  42 22   3.5   1.9 | -60.4 -76.7  275  40 21   3.8   2.1
 40000 -54.2 -65.6  255  38 20   8.3   4.6 | -53.6 -64.5  260  39 20   7.2   4.0
 38000 -49.2 -56.6  250  34 18   8.3   4.6 | -49.3 -56.7  260  35 18   7.2   3.9
 36000 -44.2 -47.6  245  30 16   8.4   4.6 | -45.0 -49.0  255  31 16   7.9   4.3
 34000 -39.1 -38.4  250  27 14   8.5   4.7 | -39.7 -39.5  255  29 15   8.9   4.9
 32000 -34.0 -29.2  255  24 12   9.2   5.1 | -34.4 -29.9  255  26 14   9.6   5.3
 30000 -29.3 -20.7  265  20 10   7.8   4.3 | -29.6 -21.3  260  23 12   8.0   4.4
 29000 -27.0 -16.6  265  18  9   7.8   4.3 | -27.2 -17.0  265  22 11   8.0   4.4
 28000 -24.2 -11.6  275  16  8   6.9   3.8 | -24.9 -12.8  270  21 11   7.2   4.0
 27000 -22.2  -8.0  280  14  7   7.0   3.8 | -22.3  -8.1  280  17  9   7.0   3.9
 26000 -20.1  -4.2  290  13  7   7.0   3.8 | -20.2  -4.4  290  15  8   7.1   3.9
 25000 -18.1  -0.6  300  12  6   6.6   3.6 | -18.2  -0.8  300  14  7   6.9   3.8
 24000 -16.2   2.8  310  11  6   6.5   3.6 | -16.1   3.0  310  12  6   6.9   3.8
 23000 -14.3   6.3  320  11  6   6.5   3.6 | -14.1   6.6  325  11  6   6.9   3.8
 22000 -12.4   9.7  330  11  6   6.6   3.6 | -12.1  10.2  335  11  6   6.7   3.7
 21000 -10.5  13.1  345  11  6   6.7   3.7 | -10.2  13.6  345  10  5   6.6   3.6
 20000  -8.5  16.7  355  11  6   6.7   3.7 |  -8.3  17.1  355   9  5   6.7   3.7
 19500  -7.6  18.3  360  11  6   6.7   3.7 |  -7.3  18.9  360   9  4   6.6   3.6
 19000  -6.6  20.1  005  11  6   6.8   3.8 |  -6.4  20.5  010   8  4   6.2   3.4
 18500  -5.6  21.9  015  11  6   6.8   3.8 |  -5.5  22.1  025   7  4   6.1   3.4
 18000  -4.6  23.7  020  11  6   7.3   4.0 |  -4.6  23.7  035   7  3   7.3   4.0
 17500  -3.5  25.7  030  10  5   7.4   4.0 |  -3.5  25.7  045   6  3   7.6   4.2
 17000  -2.5  27.5  040  10  5   7.3   4.0 |  -2.4  27.7  060   6  3   8.0   4.4
 16500  -1.4  29.5  045   9  4   7.1   3.9 |  -1.0  30.2  065   5  3   9.7   5.3
 16000  -0.4  31.3  050   8  4   7.0   3.8 |   0.4  32.7  070   5  3   9.6   5.3
 15500   0.7  33.3  055   7  4   8.9   4.9 |   1.9  35.4  075   5  2  10.1   5.6
 15000   2.0  35.6  055   6  3   8.8   4.9 |   3.4  38.1  090   4  2  10.1   5.6
 14500   3.4  38.1  060   6  3   9.5   5.2 |   4.9  40.8  100   4  2   9.5   5.2
 14000   5.5  41.9  070   5  3   9.9   5.4 |   7.0  44.6  135   3  2   9.2   5.1
 13500   7.0  44.6  075   5  2   9.4   5.2 |   8.3  46.9  155   4  2   8.6   4.7
 13000   8.4  47.1  085   4  2   9.4   5.2 |   9.6  49.3  175   5  2   8.5   4.7
 12500   9.8  49.6  090   4  2   9.5   5.2 |  10.9  51.6  190   6  3   8.9   4.9
 12000  11.2  52.2  105   4  2   9.5   5.2 |  12.1  53.8  200   7  4   8.4   4.6
 11750  11.9  53.4  110   4  2   9.5   5.2 |  12.7  54.9  205   8  4   8.3   4.5
 11500  12.6  54.7  115   4  2  10.2   5.6 |  13.4  56.1  205   9  4   9.8   5.4
 11250  13.4  56.1  125   4  2   9.5   5.2 |  14.1  57.4  210   9  5   9.1   5.0
 11000  14.0  57.2  130   4  2   8.6   4.7 |  14.7  58.5  215  10  5   7.3   4.0
 10750  14.7  58.5  140   4  2   8.8   4.8 |  15.3  59.5  220  11  6   7.6   4.2
 10500  15.4  59.7  145   5  2   9.4   5.1 |  15.8  60.4  220  12  6   8.5   4.7
 10250  16.1  61.0  150   5  2  10.0   5.5 |  16.5  61.7  225  12  6   9.5   5.2
 10000  16.8  62.2  160   5  3   8.3   4.6 |  17.2  63.0  225  13  7   8.7   4.8
  9750  17.3  63.1  165   6  3   7.2   3.9 |  17.8  64.0  230  14  7   8.3   4.6
  9500  17.9  64.2  170   7  4   7.7   4.3 |  18.4  65.1  230  15  8   8.4   4.6
  9250  18.5  65.3  175   8  4   8.1   4.4 |  19.0  66.2  235  16  8   8.4   4.6
  9000  19.0  66.2  180   8  4   7.4   4.1 |  19.6  67.3  235  16  8   8.6   4.7
  8750  19.5  67.1  185   9  5   5.5   3.0 |  20.3  68.5  240  17  9   9.4   5.2
  8500  19.8  67.6  190  11  5   3.9   2.2 |  20.9  69.6  240  17  9   7.4   4.1
  8250  20.1  68.2  195  12  6   3.6   2.0 |  21.3  70.3  240  17  9   5.6   3.1
  8000  20.3  68.5  200  13  7   4.0   2.2 |  21.7  71.1  245  17  9   6.2   3.4
  7750  20.5  68.9  205  14  7   2.8   1.6 |  22.1  71.8  245  17  8   5.9   3.2
  7500  20.4  68.7  205  15  8   0.6   0.3 |  22.3  72.1  245  16  8   2.5   1.4
  7250  20.4  68.7  210  14  7   0.1   0.0 |  22.2  72.0  245  13  7  -0.2  -0.1
  7000  20.3  68.5  210  12  6   0.4   0.2 |  22.1  71.8  245  11  6   2.0   1.1
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

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 Air Force Academy
in Colorado Springs, Colorado at

                   North Latitude:  38 deg 58 min 48.000 sec
                   West Longitude: 104 deg 49 min 12.000 sec
                   Elevation: 6572 feet (2003 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.