Soaring Guidance
Issued by NWS Grand Junction, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
000
UXUS97 KGJT 131213
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0613 MDT Monday, July 13, 2020

This forecast is for Monday, July 13, 2020:

If the trigger temperature of 87.4 F/30.8 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1855 ft/min (9.4 m/s)
   Maximum height of thermals.................. 22381 ft MSL (17015 ft AGL)

Forecast maximum temperature................... 99.0 F/37.7 C
Time of trigger temperature.................... 1045 MDT
Time of overdevelopment........................ 2000 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 16829 ft MSL (11463 ft AGL)
Thermal soaring outlook for Tuesday 07/14...... Excellent

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

Remarks...

***ATTENTION Soaring Forecast Users***The National Weather Service in Boulder wants to hear from you.
Please send and email to paul.t.schlatter@noaa.gov and let us know how you use the Soaring Forecast.  Thanks!

Sunrise/Sunset.................... 05:59:41 / 20:40:19 MDT
Total possible sunshine........... 14 hr 40 min 39 sec (880 min 39 sec)
Altitude of sun at 13:20:00 MDT... 72.04 degrees

Upper air data from numerical model forecast valid on 07/13/2020 at 0600 MDT

Freezing level.................. 16672 ft MSL (11306 ft AGL)
Convective condensation level... 16773 ft MSL (11407 ft AGL)
Lifted condensation level....... 18199 ft MSL (12833 ft AGL)
Lifted index.................... -5.5
K index......................... +30.2

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  -65.9 -86.6   270   17    9   2.2   1.2      M     M       M      M    M
 45000  -61.0 -77.8   265   23   12   5.6   3.1      M     M       M      M    M
 40000  -52.3 -62.1   260   26   13   6.7   3.7      M     M       M      M    M
 38000  -48.3 -54.9   265   25   13   6.8   3.7      M     M       M      M    M
 36000  -43.7 -46.7   265   25   13   7.3   4.0      M     M       M      M    M
 34000  -38.9 -38.0   265   25   13   7.9   4.3      M     M       M      M    M
 32000  -34.2 -29.6   265   25   13   8.0   4.4      M     M       M      M    M
 30000  -29.6 -21.3   265   24   12   7.6   4.2   45.7 114.3     6.5      M    M
 29000  -27.4 -17.3   265   23   12   7.6   4.2   45.0 112.9     6.0      M    M
 28000  -25.1 -13.2   265   23   12   6.9   3.8   44.2 111.6     5.4      M    M
 27000  -23.1  -9.6   265   21   11   6.8   3.7   42.9 109.3     4.5      M    M
 26000  -21.1  -6.0   270   20   10   6.9   3.8   41.9 107.3     3.6      M    M
 25000  -19.1  -2.4   270   19   10   6.8   3.7   40.9 105.6     2.9      M    M
 24000  -17.2   1.0   270   18    9   6.4   3.5   39.6 103.3     1.8      M    M
 23000  -15.3   4.5   270   18    9   6.5   3.5   38.4 101.0     0.7      M    M
 22000  -13.5   7.7   270   18    9   7.2   3.9   37.3  99.1    -0.3   1631  8.3
 21000  -11.0  12.2   265   17    9   8.6   4.7   36.7  98.1    -0.8   1528  7.8
 20000   -7.9  17.8   265   16    8   8.7   4.8   36.3  97.3    -1.4   1398  7.1
 19500   -6.7  19.9   265   16    8   8.5   4.7   36.1  97.0    -1.5   1346  6.8
 19000   -5.5  22.1   265   15    8   8.2   4.5   35.8  96.5    -1.9   1296  6.6
 18500   -4.3  24.3   265   15    8   8.2   4.5   35.6  96.1    -2.1   1246  6.3
 18000   -3.1  26.4   265   15    8   8.4   4.6   35.3  95.6    -2.4   1195  6.1
 17500   -1.9  28.6   265   14    7   8.4   4.6   35.1  95.2    -2.7   1144  5.8
 17000   -0.7  30.7   265   14    7   8.6   4.7   34.9  94.8    -3.0   1093  5.6
 16500    0.6  33.1   265   14    7   8.8   4.8   34.7  94.5    -3.2   1040  5.3
 16000    1.9  35.4   260   13    7   8.7   4.8   34.5  94.2    -3.3    986  5.0
 15500    3.2  37.8   260   13    7   9.5   5.2   34.4  94.0    -3.5    931  4.7
 15000    4.6  40.3   260   13    7   9.4   5.2   34.4  93.9    -3.5    874  4.4
 14500    6.0  42.8   255   13    6   8.7   4.8   34.3  93.7    -3.7    819  4.2
 14000    7.2  45.0   255   12    6   8.5   4.7   34.1  93.4    -3.9    766  3.9
 13500    8.5  47.3   255   12    6   8.6   4.7   33.9  93.0    -4.1    714  3.6
 13000    9.8  49.6   250   12    6   8.7   4.8   33.7  92.7    -4.3    660  3.4
 12500   11.1  52.0   250   11    6   8.8   4.8   33.6  92.4    -4.5    607  3.1
 12000   12.4  54.3   250   11    5   8.9   4.9   33.4  92.1    -4.7    553  2.8
 11500   13.7  56.7   250   10    5   8.9   4.9   33.3  91.9    -4.8    499  2.5
 11000   15.0  59.0   250   10    5   8.6   4.7   33.1  91.7    -5.0    445  2.3
 10500   16.3  61.3   250    9    5   5.4   3.0   33.0  91.4    -5.1    390  2.0
 10250   16.6  61.9   250    9    4   5.0   2.7   32.5  90.5    -5.6    375  1.9
 10000   17.2  63.0   250    8    4   9.0   4.9   32.4  90.3    -5.8    350  1.8
  9750   17.8  64.0   245    8    4   8.0   4.4   32.2  90.0    -5.9    324  1.6
  9500   18.4  65.1   245    7    4   8.1   4.5   32.1  89.8    -6.0    299  1.5
  9250   18.9  66.0   245    7    3   6.4   3.5   32.0  89.5    -6.2    275  1.4
  9000   19.3  66.7   245    6    3   5.1   2.8   31.6  88.9    -6.6    256  1.3
  8750   19.7  67.5   245    5    3   5.3   2.9   31.3  88.3    -7.0    237  1.2
  8500   20.1  68.2   240    4    2   4.9   2.7   30.9  87.6    -7.3    219  1.1
  8250   20.4  68.7   240    3    2   3.2   1.7   30.5  86.9    -7.8    202  1.0
  8000   20.6  69.1   230    2    1   3.1   1.7   29.9  85.9    -8.3    189  1.0
  7750   20.8  69.4   200    2    1   4.1   2.3   29.5  85.1    -8.8    174  0.9
  7500   21.1  70.0   155    1    1   4.1   2.2   29.0  84.3    -9.3    158  0.8
  7250   21.4  70.5   135    2    1   4.5   2.4   28.6  83.5    -9.7    141  0.7
  7000   21.8  71.2   130    3    2   4.1   2.3   28.2  82.8   -10.2    124  0.6
  6750   22.1  71.8   130    4    2   5.1   2.8   27.8  82.1   -10.6    107  0.5
  6500   22.4  72.3   130    5    3   0.4   0.2   27.4  81.3   -11.1     91  0.5
  6250   22.1  71.8   125    5    3  -4.9  -2.7   26.4  79.5   -12.1     92  0.5
  6000   21.8  71.2   120    6    3  -2.4  -1.3   25.4  77.6   -13.1     93  0.5
  5750   21.6  70.9   115    6    3  -6.6  -3.6   24.4  75.9   -14.1     93  0.5
  5500   20.3  68.5   105    5    3 -26.6 -14.6   22.5  72.5   -16.1    122  0.6
  5250      M     M     M    M    M     M     M      M     M       M      M    M
  5000      M     M     M    M    M     M     M      M     M       M      M    M

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

           07/13/2020 at 0900 MDT          |       07/13/2020 at 1200 MDT
                                           |
CAPE...  +217.7    LI...       -1.0        | CAPE...  +586.3    LI...       -2.4
CINH...  -230.8    K Index... +27.4        | CINH...   -15.6    K Index... +27.2
                                           |
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 -66.0 -86.8  265  18 10   2.2   1.2 | -65.6 -86.1  265  21 11   1.8   1.0
 45000 -61.0 -77.8  265  26 13   5.7   3.1 | -61.1 -78.0  265  29 15   5.4   3.0
 40000 -52.2 -62.0  265  29 15   6.7   3.7 | -52.7 -62.9  265  31 16   7.0   3.8
 38000 -48.2 -54.8  265  29 15   6.8   3.7 | -48.5 -55.3  265  31 16   7.0   3.8
 36000 -43.6 -46.5  265  29 15   7.2   3.9 | -43.8 -46.8  265  30 15   7.6   4.1
 34000 -39.0 -38.2  265  29 15   7.7   4.2 | -38.8 -37.8  265  29 15   8.2   4.5
 32000 -34.3 -29.7  265  28 14   7.8   4.3 | -33.9 -29.0  265  28 14   8.3   4.5
 30000 -30.1 -22.2  265  25 13   7.1   3.9 | -29.6 -21.3  265  25 13   7.1   3.9
 29000 -27.9 -18.2  265  24 12   7.1   3.9 | -27.4 -17.3  265  24 12   7.1   3.9
 28000 -25.8 -14.4  265  23 12   7.3   4.0 | -25.3 -13.5  260  23 12   6.6   3.6
 27000 -23.6 -10.5  265  22 11   7.3   4.0 | -23.4 -10.1  260  21 11   6.5   3.6
 26000 -21.5  -6.7  265  20 11   7.3   4.0 | -21.4  -6.5  260  19 10   6.6   3.6
 25000 -19.3  -2.7  265  19 10   7.1   3.9 | -19.5  -3.1  260  18  9   6.7   3.7
 24000 -17.5   0.5  265  18  9   6.0   3.3 | -17.4   0.7  260  18  9   7.1   3.9
 23000 -15.7   3.7  260  17  9   6.1   3.4 | -15.3   4.5  255  18  9   7.1   3.9
 22000 -14.0   6.8  260  16  8   7.1   3.9 | -13.2   8.2  255  19 10   7.3   4.0
 21000 -11.4  11.5  255  15  8   8.9   4.9 | -10.5  13.1  250  18  9   7.8   4.3
 20000  -8.2  17.2  250  14  7   9.0   5.0 |  -8.2  17.2  250  17  9   7.9   4.3
 19500  -6.9  19.6  245  14  7   8.9   4.9 |  -7.1  19.2  245  17  9   8.2   4.5
 19000  -5.7  21.7  245  14  7   8.7   4.8 |  -5.9  21.4  245  17  9   8.5   4.7
 18500  -4.4  24.1  250  13  7   8.9   4.9 |  -4.7  23.5  245  16  8   8.6   4.7
 18000  -3.2  26.2  250  13  7   7.8   4.3 |  -3.4  25.9  245  15  8   8.2   4.5
 17500  -2.1  28.2  250  13  7   7.8   4.3 |  -2.2  28.0  245  15  8   8.2   4.5
 17000  -0.9  30.4  255  13  7   8.4   4.6 |  -1.0  30.2  245  14  7   8.4   4.6
 16500   0.4  32.7  255  13  7   9.1   5.0 |   0.2  32.4  245  14  7   8.7   4.8
 16000   1.8  35.2  255  13  7   9.1   5.0 |   1.5  34.7  245  13  7   8.7   4.7
 15500   3.1  37.6  255  13  7   9.3   5.1 |   2.8  37.0  250  13  7   9.7   5.3
 15000   4.5  40.1  255  13  7   9.3   5.1 |   4.2  39.6  250  13  7   9.6   5.3
 14500   5.9  42.6  260  13  7   9.5   5.2 |   5.6  42.1  250  13  7   9.5   5.2
 14000   7.4  45.3  260  13  7   9.6   5.3 |   7.0  44.6  255  13  7   9.5   5.2
 13500   8.8  47.8  260  13  7   9.4   5.2 |   8.4  47.1  255  13  7   9.7   5.3
 13000  10.2  50.4  260  13  7   9.3   5.1 |   9.9  49.8  255  13  7   9.9   5.4
 12500  11.6  52.9  265  13  7   9.0   5.0 |  11.4  52.5  255  13  7   9.6   5.3
 12000  12.9  55.2  260  13  7   8.4   4.6 |  12.8  55.0  255  13  7   9.2   5.0
 11500  14.1  57.4  260  12  6   8.2   4.5 |  14.1  57.4  255  13  7   8.9   4.9
 11000  15.2  59.4  260  11  6   7.0   3.8 |  15.4  59.7  255  13  7   8.0   4.4
 10500  16.2  61.2  255  10  5   5.0   2.7 |  16.5  61.7  250  13  7  11.2   6.2
 10250  16.5  61.7  250  10  5   5.5   3.0 |  17.5  63.5  250  13  7  11.7   6.4
 10000  17.1  62.8  250   9  5   8.8   4.8 |  18.2  64.8  250  12  6   7.6   4.2
  9750  17.7  63.9  245   8  4   8.0   4.4 |  18.8  65.8  250  11  6   8.8   4.8
  9500  18.3  64.9  240   7  4   8.0   4.4 |  19.4  66.9  245  11  6   8.1   4.4
  9250  18.8  65.8  235   7  3   7.6   4.2 |  20.0  68.0  245  10  5   7.9   4.3
  9000  19.4  66.9  230   6  3   7.7   4.2 |  20.5  68.9  245   9  5   8.5   4.7
  8750  19.9  67.8  225   6  3   8.1   4.4 |  21.1  70.0  240   8  4   8.7   4.8
  8500  20.5  68.9  215   6  3   7.5   4.1 |  21.7  71.1  240   7  4   8.9   4.9
  8250  21.0  69.8  210   6  3   6.5   3.6 |  22.4  72.3  240   6  3   9.6   5.3
  8000  21.4  70.5  200   6  3   4.9   2.7 |  23.2  73.8  235   6  3   9.9   5.4
  7750  21.7  71.1  190   6  3   3.8   2.1 |  23.9  75.0  235   6  3   9.8   5.4
  7500  22.0  71.6  185   7  4   3.8   2.1 |  24.6  76.3  235   6  3  10.0   5.5
  7250  22.3  72.1  180   7  4   3.5   1.9 |  25.3  77.5  235   6  3  10.2   5.6
  7000  22.5  72.5  175   7  4   3.6   2.0 |  26.1  79.0  235   6  3  10.2   5.6
  6750  22.8  73.0  170   7  4   3.2   1.8 |  26.8  80.2  235   6  3   9.7   5.3
  6500  23.1  73.6  165   7  3   5.4   3.0 |  27.6  81.7  235   5  3  10.4   5.7
  6250  23.6  74.5  165   6  3   7.8   4.3 |  28.4  83.1  235   5  3  11.4   6.3
  6000  24.0  75.2  165   5  3   6.5   3.6 |  29.2  84.6  235   5  3  10.4   5.7
  5750  24.5  76.1  160   4  2   9.1   5.0 |  30.0  86.0  240   5  3  12.6   6.9
  5500  25.5  77.9  160   4  2  18.5  10.2 |  31.4  88.5  240   5  3  25.3  13.9
  5250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           07/13/2020 at 1500 MDT          |       07/13/2020 at 1800 MDT
                                           |
CAPE...  +117.9    LI...       +0.1        | CAPE...  +229.7    LI...       -0.4
CINH...   -13.4    K Index... +19.9        | CINH...   -25.1    K Index... +25.6
                                           |
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 -66.0 -86.8  265  20 10   2.0   1.1 | -66.4 -87.5  265  20 10   1.6   0.9
 45000 -61.3 -78.3  270  28 14   5.5   3.0 | -61.9 -79.4  270  26 13   5.8   3.2
 40000 -52.7 -62.9  270  28 14   7.2   3.9 | -52.9 -63.2  265  24 13   7.5   4.1
 38000 -47.8 -54.0  270  28 14   7.2   3.9 | -48.4 -55.1  265  25 13   7.5   4.1
 36000 -43.5 -46.3  270  27 14   7.7   4.2 | -43.3 -45.9  265  26 14   7.9   4.3
 34000 -38.6 -37.5  270  27 14   8.2   4.5 | -38.4 -37.1  265  25 13   8.1   4.5
 32000 -33.7 -28.7  270  26 13   8.2   4.5 | -33.5 -28.3  270  23 12   8.1   4.5
 30000 -29.2 -20.6  270  24 12   7.4   4.1 | -29.1 -20.4  265  21 11   7.4   4.1
 29000 -27.0 -16.6  270  23 12   7.4   4.1 | -26.9 -16.4  265  20 10   7.5   4.1
 28000 -24.8 -12.6  265  22 11   6.4   3.5 | -24.8 -12.6  265  19 10   6.9   3.8
 27000 -22.9  -9.2  265  21 11   6.3   3.5 | -22.7  -8.9  265  18  9   6.9   3.8
 26000 -21.1  -6.0  265  20 10   6.4   3.5 | -20.7  -5.3  265  17  9   7.0   3.8
 25000 -19.2  -2.6  260  19 10   6.7   3.7 | -18.6  -1.5  260  17  9   7.0   3.8
 24000 -16.9   1.6  260  18  9   7.8   4.3 | -16.6   2.1  265  16  8   7.0   3.8
 23000 -14.6   5.7  255  17  9   7.8   4.3 | -14.5   5.9  265  15  8   7.0   3.9
 22000 -12.3   9.9  255  17  9   7.7   4.2 | -12.4   9.7  265  14  7   7.6   4.1
 21000  -9.5  14.9  250  18  9   7.6   4.2 |  -9.9  14.2  265  13  7   8.4   4.6
 20000  -7.3  18.9  245  19 10   7.7   4.2 |  -6.8  19.8  260  13  6   8.4   4.6
 19500  -6.2  20.8  245  19 10   8.1   4.5 |  -5.6  21.9  260  12  6   8.3   4.6
 19000  -4.9  23.2  245  19 10   8.7   4.8 |  -4.4  24.1  255  12  6   8.1   4.5
 18500  -3.6  25.5  245  19 10   8.7   4.8 |  -3.2  26.2  255  12  6   8.1   4.4
 18000  -2.4  27.7  245  19 10   8.5   4.7 |  -2.0  28.4  255  12  6   8.7   4.8
 17500  -1.1  30.0  245  18  9   8.6   4.7 |  -0.7  30.7  255  12  6   8.7   4.8
 17000   0.1  32.2  240  18  9   8.8   4.8 |   0.6  33.1  250  12  6   8.7   4.8
 16500   1.4  34.5  240  18  9   9.1   5.0 |   1.8  35.2  250  12  6   8.7   4.8
 16000   2.8  37.0  240  17  9   9.1   5.0 |   3.1  37.6  250  12  6   8.7   4.8
 15500   4.1  39.4  240  17  9   8.9   4.9 |   4.4  39.9  250  13  7   9.0   4.9
 15000   5.4  41.7  240  17  8   8.9   4.9 |   5.7  42.3  250  13  7   9.0   4.9
 14500   6.7  44.1  245  16  8   9.0   4.9 |   7.0  44.6  250  13  7   9.0   4.9
 14000   8.0  46.4  245  15  8   9.0   4.9 |   8.3  46.9  250  14  7   9.0   4.9
 13500   9.3  48.7  245  15  8   9.3   5.1 |   9.6  49.3  250  14  7   9.2   5.0
 13000  10.7  51.3  245  14  7   9.5   5.2 |  11.0  51.8  250  14  7   9.5   5.2
 12500  12.1  53.8  245  14  7   9.5   5.2 |  12.4  54.3  250  14  7   9.5   5.2
 12000  13.5  56.3  245  13  7   9.4   5.2 |  13.8  56.8  250  14  7   9.4   5.2
 11500  14.9  58.8  250  12  6   9.2   5.1 |  15.2  59.4  250  14  7   9.4   5.1
 11000  16.2  61.2  250  12  6   8.1   4.5 |  16.5  61.7  250  14  7   8.4   4.6
 10500  17.4  63.3  250  11  6  11.4   6.3 |  17.8  64.0  255  13  7  11.3   6.2
 10250  18.4  65.1  250  11  6  12.7   6.9 |  18.8  65.8  255  13  7  12.3   6.7
 10000  19.1  66.4  250  11  6   9.2   5.1 |  19.5  67.1  255  13  7   9.2   5.0
  9750  19.9  67.8  250  11  6  10.2   5.6 |  20.2  68.4  255  13  7  10.1   5.5
  9500  20.6  69.1  250  11  6   9.8   5.4 |  21.0  69.8  255  13  7   9.5   5.2
  9250  21.3  70.3  250  11  5   9.5   5.2 |  21.7  71.1  255  13  7   9.2   5.0
  9000  22.0  71.6  250  11  5   9.5   5.2 |  22.4  72.3  255  13  7   9.5   5.2
  8750  22.7  72.9  250  11  5   9.5   5.2 |  23.1  73.6  255  13  7   9.7   5.3
  8500  23.5  74.3  255  10  5   9.7   5.3 |  23.8  74.8  255  13  7   9.7   5.3
  8250  24.2  75.6  255  10  5  11.2   6.1 |  24.6  76.3  255  13  7  12.0   6.6
  8000  25.1  77.2  255  10  5  10.6   5.8 |  25.5  77.9  255  13  7  11.0   6.0
  7750  25.8  78.4  255  10  5   9.4   5.2 |  26.2  79.2  255  13  6   8.5   4.7
  7500  26.5  79.7  255  10  5   9.9   5.4 |  26.9  80.4  255  12  6   9.4   5.2
  7250  27.3  81.1  255  10  5  10.1   5.6 |  27.6  81.7  255  12  6  10.4   5.7
  7000  28.0  82.4  255  10  5  10.3   5.6 |  28.4  83.1  255  12  6  10.6   5.8
  6750  28.8  83.8  255  10  5  10.1   5.5 |  29.1  84.4  255  12  6   9.6   5.3
  6500  29.6  85.3  255  10  5  10.5   5.8 |  29.9  85.8  255  12  6  10.0   5.5
  6250  30.4  86.7  255   9  5  11.3   6.2 |  30.7  87.3  260  12  6  10.6   5.8
  6000  31.2  88.2  255   9  5  11.0   6.0 |  31.5  88.7  260  11  6  11.0   6.1
  5750  32.1  89.8  255   9  5  11.9   6.5 |  32.3  90.1  260  11  6   9.7   5.3
  5500  33.2  91.8  255   9  4  22.9  12.6 |  33.0  91.4  260  10  5  13.5   7.4
  5250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  5000     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 at Walker Field in Grand
Junction, Colorado at

                   North Latitude:  39 deg 07 min 00.001 sec
                   West Longitude: 108 deg 31 min 59.998 sec
                   Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado.  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.