Soaring Guidance
Issued by NWS Grand Junction, CO

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 211241
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0641 MDT Tuesday, October 21, 2014

This forecast is for Tuesday, October 21, 2014:

If the trigger temperature of 70.6 F/21.4 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 6681 ft MSL (1842 ft AGL)

Forecast maximum temperature................... 68.0 F/20.5 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 5211 ft MSL (372 ft AGL)
Thermal soaring outlook for Wednesday 10/22.... Fair

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

Remarks...

Sunrise/Sunset.................... 07:30:04 / 18:28:22 MDT
Total possible sunshine........... 10 hr 58 min 19 sec (658 min 19 sec)
Altitude of sun at 12:58:48 MDT... 40.04 degrees

Upper air data from rawinsonde observation taken on 10/21/2014 at 0600 MDT

Freezing level.................. 12449 ft MSL (7610 ft AGL)
Convective condensation level... 12897 ft MSL (8058 ft AGL)
Lifted condensation level....... 11780 ft MSL (6941 ft AGL)
Lifted index.................... +2.3
K index......................... +25.5

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  -66.3 -87.3   220   49   25   0.9   0.5   85.7 186.3    37.9      M    M
 45000  -60.3 -76.5   205   46   24   5.5   3.0   71.2 160.2    31.7      M    M
 40000  -50.1 -58.2   215   48   25   1.6   0.9   64.4 147.9    29.3      M    M
 38000  -49.5 -57.1   220   51   26   6.4   3.5   56.5 133.6    24.8      M    M
 36000  -45.3 -49.5   220   47   24   7.0   3.8   54.0 129.3    23.7      M    M
 34000  -42.2 -44.0   210   33   17  -9.8  -5.4   49.2 120.6    20.9      M    M
 32000  -39.3 -38.7   220   26   13   6.4   3.5   45.1 113.3    18.5      M    M
 30000  -34.7 -30.5   225   20   10   1.5   0.8   43.5 110.2    17.7      M    M
 29000  -33.6 -28.5   245   25   13   7.5   4.1   41.1 106.0    16.1      M    M
 28000  -30.7 -23.3   245   27   14   9.6   5.3   41.0 105.7    16.2      M    M
 27000  -28.0 -18.4   245   28   14   8.9   4.9   40.8 105.4    16.2      M    M
 26000  -25.3 -13.5   245   29   15   8.6   4.7   40.4 104.8    16.1      M    M
 25000  -23.6 -10.5   245   31   16   3.0   1.6   38.9 102.1    15.2      M    M
 24000  -22.4  -8.3   245   32   16   7.9   4.3   36.8  98.3    13.6      M    M
 23000  -21.1  -6.0   240   31   16   0.4   0.2   34.9  94.8    12.1      M    M
 22000  -19.7  -3.5   235   31   16   8.5   4.7   33.1  91.5    10.7      M    M
 21000  -16.9   1.6   235   30   16   9.5   5.2   32.8  91.0    10.6      M    M
 20000  -14.7   5.5   230   30   15   6.7   3.7   32.0  89.6    10.0      M    M
 19500  -13.8   7.2   230   30   15   6.4   3.5   31.4  88.5     9.5      M    M
 19000  -13.3   8.1   230   29   15   6.1   3.4   30.4  86.7     8.6      M    M
 18500  -13.6   7.5   225   30   15   1.5   0.8   27.5  81.5     6.1      M    M
 18000  -12.6   9.3   220   31   16   7.0   3.8   27.0  80.6     5.8      M    M
 17500  -11.4  11.5   220   32   16   7.2   3.9   26.6  79.9     5.5      M    M
 17000  -10.4  13.3   215   33   17   7.2   3.9   26.1  79.0     5.0      M    M
 16500   -9.4  15.1   210   31   16   7.2   4.0   25.7  78.2     4.6      M    M
 16000   -8.4  16.9   210   30   15   7.4   4.1   25.3  77.5     4.2      M    M
 15500   -7.3  18.9   205   29   15   8.1   4.5   25.0  76.9     3.9      M    M
 15000   -6.1  21.0   205   29   15   7.4   4.1   24.7  76.4     3.7      M    M
 14500   -5.2  22.6   210   27   14   7.0   3.8   24.1  75.4     3.1      M    M
 14000   -3.9  25.0   215   26   13   8.8   4.8   23.9  75.0     2.9      M    M
 13500   -2.6  27.3   215   25   13   8.8   4.8   23.7  74.7     2.8      M    M
 13000   -1.3  29.7   215   25   13   8.8   4.8   23.6  74.5     2.6      M    M
 12500   -0.1  31.8   215   24   13   8.8   4.8   23.5  74.2     2.5      M    M
 12000    1.2  34.2   215   24   12   8.8   4.8   23.3  74.0     2.4      M    M
 11500    2.5  36.5   220   24   12   8.8   4.8   23.1  73.7     2.2      M    M
 11000    3.8  38.8   220   24   12   8.8   4.8   23.0  73.4     2.0      M    M
 10500    5.1  41.2   225   24   12   8.8   4.8   22.8  73.1     1.8      M    M
 10250    5.8  42.4   225   24   12   9.1   5.0   22.8  73.0     1.8      M    M
 10000    6.5  43.7   220   23   12   9.5   5.2   22.7  72.9     1.7      M    M
  9750    7.2  45.0   220   21   11   9.5   5.2   22.7  72.9     1.7      M    M
  9500    7.9  46.2   215   20   10   9.1   5.0   22.7  72.9     1.7      M    M
  9250    8.5  47.3   210   19   10   8.1   4.4   22.6  72.7     1.6      M    M
  9000    9.1  48.4   205   18    9   7.8   4.3   22.5  72.5     1.5      M    M
  8750    9.6  49.3   205   17    9   7.8   4.3   22.3  72.2     1.3      M    M
  8500   10.2  50.4   205   16    8   7.8   4.3   22.2  71.9     1.2      M    M
  8250   10.8  51.4   200   14    7   7.8   4.3   22.0  71.7     1.0      M    M
  8000   11.4  52.5   200   13    7   7.8   4.3   21.9  71.4     0.9      M    M
  7750   11.9  53.4   200   14    7   7.8   4.3   21.8  71.2     0.7      M    M
  7500   12.5  54.5   195   14    7   7.9   4.3   21.6  70.9     0.6      M    M
  7250   13.1  55.6   195   15    8   7.9   4.3   21.5  70.6     0.4      M    M
  7000   13.6  56.5   195   16    8   7.9   4.3   21.3  70.4     0.3      M    M
  6750   14.2  57.6   190   17    9   7.9   4.3   21.2  70.1     0.1      M    M
  6500   14.8  58.6   180   18    9   7.8   4.3   21.0  69.8    -0.1     39  0.2
  6250   15.3  59.5   175   19   10   8.0   4.4   20.9  69.6    -0.2     14  0.1
  6000   15.9  60.6   170   21   11   7.5   4.1   20.7  69.3    -0.4      M    M
  5750   16.5  61.7   165   19   10   9.2   5.1   20.6  69.0    -0.6      M    M
  5500   16.9  62.4   160   15    8  -1.7  -0.9   20.3  68.6    -0.9      M    M
  5250   16.2  61.2   150   12    6 -13.3  -7.3   18.8  65.9    -2.3      M    M
  5000   15.5  59.9   135   10    5  -4.7  -2.6   17.3  63.2    -3.7      M    M

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

           10/21/2014 at 0900 MDT          |       10/21/2014 at 1200 MDT
                                           |
K index... +29.8  LI... -1.8               | K index... +28.9  LI... -1.3
CAPE... +165.3  CIN... -8.7                | CAPE... +180.6  CIN... -13.0
                                           |
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 -65.7 -86.3  215  41 21   3.8   2.1 | -64.6 -84.3  215  47 24   3.5   1.9
 45000 -59.6 -75.3  215  55 28   5.5   3.0 | -59.1 -74.4  210  58 30   4.8   2.6
 40000 -50.9 -59.6  220  56 29   5.1   2.8 | -51.6 -60.9  215  66 34   4.5   2.5
 38000 -48.3 -54.9  220  52 27   4.4   2.4 | -49.4 -56.9  220  63 32   3.6   2.0
 36000 -45.6 -50.1  225  49 25   4.4   2.4 | -47.3 -53.1  220  59 30   3.6   2.0
 34000 -43.0 -45.4  225  44 23   4.4   2.4 | -44.8 -48.6  225  53 27   4.8   2.6
 32000 -40.3 -40.5  225  37 19   4.4   2.4 | -41.9 -43.4  220  44 23   4.8   2.6
 30000 -36.8 -34.2  230  32 16   7.5   4.1 | -37.9 -36.2  220  38 20   8.8   4.8
 29000 -34.6 -30.3  230  31 16   7.5   4.1 | -35.3 -31.5  220  36 19   8.8   4.8
 28000 -31.8 -25.2  230  29 15   7.6   4.2 | -32.7 -26.9  220  35 18   8.8   4.8
 27000 -29.7 -21.5  230  28 15   6.5   3.5 | -29.8 -21.6  220  33 17   6.4   3.5
 26000 -27.8 -18.0  225  28 14   6.4   3.5 | -27.9 -18.2  220  33 17   6.4   3.5
 25000 -25.8 -14.4  225  27 14   6.5   3.6 | -26.0 -14.8  220  32 17   6.4   3.5
 24000 -23.7 -10.7  225  26 13   7.7   4.2 | -24.0 -11.2  220  31 16   7.4   4.0
 23000 -21.5  -6.7  220  23 12   7.8   4.3 | -21.8  -7.2  215  30 16   7.4   4.0
 22000 -19.2  -2.6  220  20 11   7.8   4.3 | -19.7  -3.5  215  29 15   7.4   4.0
 21000 -17.2   1.0  220  20 10   5.7   3.1 | -17.6   0.3  215  27 14   7.0   3.9
 20000 -15.6   3.9  220  21 11   5.7   3.1 | -15.5   4.1  220  25 13   7.1   3.9
 19500 -14.7   5.5  220  22 11   5.7   3.1 | -14.5   5.9  220  23 12   7.1   3.9
 19000 -13.9   7.0  220  22 11   5.7   3.1 | -13.5   7.7  225  22 11   6.8   3.8
 18500 -13.1   8.4  220  22 12   5.8   3.2 | -12.7   9.1  230  22 11   4.8   2.6
 18000 -12.2  10.0  220  23 12   5.8   3.2 | -11.9  10.6  230  22 12   4.9   2.7
 17500 -11.3  11.7  220  23 12   7.1   3.9 | -11.1  12.0  230  23 12   6.6   3.6
 17000 -10.2  13.6  220  23 12   7.4   4.1 | -10.1  13.8  230  24 12   7.0   3.8
 16500  -9.2  15.4  220  24 12   7.3   4.0 |  -9.1  15.6  230  24 13   6.8   3.7
 16000  -8.2  17.2  220  24 12   6.8   3.7 |  -8.2  17.2  230  24 13   6.1   3.3
 15500  -7.2  19.0  220  24 12   6.8   3.7 |  -7.3  18.9  230  24 13   6.1   3.3
 15000  -6.2  20.8  225  23 12   6.9   3.8 |  -6.4  20.5  230  24 12   6.7   3.7
 14500  -5.2  22.6  225  23 12   6.9   3.8 |  -5.4  22.3  230  24 12   6.7   3.7
 14000  -4.2  24.4  225  22 11   7.1   3.9 |  -4.5  23.9  230  23 12   6.7   3.7
 13500  -2.7  27.1  230  21 11   7.2   3.9 |  -3.0  26.6  235  22 11   6.8   3.7
 13000  -1.6  29.1  230  21 11   7.8   4.3 |  -2.0  28.4  235  21 11   7.2   4.0
 12500  -0.5  31.1  230  20 10   7.7   4.2 |  -0.9  30.4  235  20 10   7.1   3.9
 12000   0.7  33.3  235  20 10   9.2   5.1 |   0.3  32.5  235  19 10   9.7   5.3
 11500   2.0  35.6  235  20 10   9.1   5.0 |   1.6  34.9  235  18  9   9.6   5.3
 11000   3.4  38.1  235  19 10   9.7   5.3 |   2.9  37.2  235  17  9   8.4   4.6
 10500   4.8  40.6  240  19 10   8.1   4.5 |   4.2  39.6  235  17  9   6.2   3.4
 10250   5.3  41.5  240  19 10   6.1   3.3 |   4.6  40.3  235  16  8   6.2   3.4
 10000   5.8  42.4  235  19 10   8.6   4.7 |   5.2  41.4  235  16  8   9.9   5.4
  9750   6.5  43.7  235  19 10  10.0   5.5 |   5.9  42.6  230  16  8   9.3   5.1
  9500   7.2  45.0  235  19 10   9.4   5.2 |   6.6  43.9  230  16  8   9.3   5.1
  9250   7.9  46.2  230  19 10   7.1   3.9 |   7.2  45.0  230  16  8   8.0   4.4
  9000   8.3  46.9  230  19 10   6.6   3.6 |   7.8  46.0  225  15  8   7.4   4.0
  8750   8.9  48.0  225  20 10   8.0   4.4 |   8.3  46.9  225  15  8   7.8   4.3
  8500   9.5  49.1  225  20 10   7.4   4.0 |   8.8  47.8  220  14  7   7.4   4.1
  8250  10.0  50.0  220  21 11   7.0   3.9 |   9.3  48.7  215  13  7   6.2   3.4
  8000  10.5  50.9  215  21 11   6.0   3.3 |   9.8  49.6  210  12  6   6.7   3.7
  7750  10.9  51.6  215  21 11   5.5   3.0 |  10.3  50.5  210  10  5   7.5   4.1
  7500  11.3  52.3  210  21 11   4.6   2.5 |  10.9  51.6  205   9  5   8.1   4.4
  7250  11.6  52.9  205  20 10   3.6   2.0 |  11.5  52.7  205   9  4   9.0   4.9
  7000  11.8  53.2  200  19 10   3.4   1.9 |  12.2  54.0  200   8  4   8.9   4.9
  6750  12.1  53.8  190  18  9   1.9   1.1 |  12.9  55.2  205   8  4   9.3   5.1
  6500  12.1  53.8  185  17  9  -2.1  -1.1 |  13.6  56.5  205   8  4  10.3   5.6
  6250  11.8  53.2  175  14  7  -3.5  -1.9 |  14.4  57.9  205   8  4  11.1   6.1
  6000  11.6  52.9  170  12  6  -5.2  -2.9 |  15.2  59.4  205   7  4  10.0   5.5
  5750  11.2  52.2  145   8  4  -2.8  -1.6 |  15.9  60.6  205   7  3   9.9   5.5
  5500  11.2  52.2  135   7  4   3.1   1.7 |  16.7  62.1  205   7  3  11.4   6.2
  5250  11.4  52.5  130   6  3   0.3   0.2 |  17.5  63.5  210   6  3  10.9   6.0
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           10/21/2014 at 1500 MDT          |       10/21/2014 at 1800 MDT
                                           |
K index... +28.5  LI... -1.2               | K index... +23.3  LI... -1.9
CAPE... +190.9  CIN... -26.4               | CAPE... +360.8  CIN... -34.7
                                           |
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 -63.8 -82.8  215  48 25   4.1   2.2 | -63.0 -81.4  225  49 25   4.1   2.3
 45000 -57.9 -72.2  215  57 30   3.4   1.9 | -57.1 -70.8  220  57 29   2.6   1.4
 40000 -52.4 -62.3  215  65 33   3.4   1.8 | -53.3 -63.9  225  57 29   2.6   1.4
 38000 -51.1 -60.0  220  63 33   2.1   1.2 | -51.7 -61.1  225  57 30   2.6   1.4
 36000 -49.9 -57.8  220  61 32   2.1   1.2 | -50.1 -58.2  225  57 30   2.6   1.4
 34000 -47.3 -53.1  220  55 28   6.5   3.6 | -47.7 -53.9  220  55 28   6.0   3.3
 32000 -43.4 -46.1  215  44 23   6.5   3.6 | -43.7 -46.7  215  50 26   6.0   3.3
 30000 -38.8 -37.8  215  36 18   9.2   5.0 | -39.2 -38.6  210  44 22   8.7   4.8
 29000 -36.0 -32.8  220  33 17   9.2   5.0 | -36.6 -33.9  210  40 21   8.8   4.8
 28000 -33.3 -27.9  225  30 15   9.2   5.0 | -34.0 -29.2  210  36 19   8.7   4.8
 27000 -30.7 -23.3  230  28 14   7.8   4.3 | -31.6 -24.9  210  34 17   7.3   4.0
 26000 -27.8 -18.0  230  27 14   7.9   4.3 | -29.4 -20.9  220  33 17   7.3   4.0
 25000 -25.5 -13.9  235  26 13   7.9   4.3 | -27.2 -17.0  225  34 17   7.3   4.0
 24000 -23.3  -9.9  235  25 13   7.1   3.9 | -24.9 -12.8  235  34 17   8.1   4.4
 23000 -21.2  -6.2  235  25 13   7.1   3.9 | -22.5  -8.5  235  32 16   8.0   4.4
 22000 -19.1  -2.4  240  25 13   7.1   3.9 | -20.1  -4.2  240  30 15   8.0   4.4
 21000 -17.0   1.4  240  25 13   7.0   3.8 | -17.8  -0.0  245  28 15   7.0   3.8
 20000 -15.0   5.0  240  25 13   7.0   3.8 | -15.7   3.7  245  27 14   7.0   3.9
 19500 -13.9   7.0  240  25 13   7.0   3.8 | -14.7   5.5  245  27 14   7.0   3.9
 19000 -12.9   8.8  240  25 13   6.9   3.8 | -13.6   7.5  250  26 14   7.0   3.9
 18500 -12.0  10.4  240  26 13   6.4   3.5 | -12.6   9.3  250  26 13   7.2   4.0
 18000 -11.0  12.2  240  26 13   6.4   3.5 | -11.5  11.3  245  26 13   7.3   4.0
 17500 -10.1  13.8  245  26 13   6.3   3.5 | -10.5  13.1  245  26 14   7.0   3.8
 17000  -9.2  15.4  245  26 13   6.3   3.4 |  -9.5  14.9  245  27 14   6.8   3.7
 16500  -8.3  17.1  245  26 13   6.2   3.4 |  -8.5  16.7  250  27 14   6.7   3.7
 16000  -7.4  18.7  245  25 13   6.1   3.3 |  -7.6  18.3  250  27 14   5.8   3.2
 15500  -6.5  20.3  245  25 13   6.1   3.4 |  -6.3  20.7  255  28 14   6.1   3.3
 15000  -5.7  21.7  245  25 13   6.0   3.3 |  -5.4  22.3  260  28 14   6.6   3.6
 14500  -4.8  23.4  245  24 12   6.0   3.3 |  -4.4  24.1  260  28 14   6.7   3.7
 14000  -3.9  25.0  245  23 12   6.1   3.3 |  -3.5  25.7  260  27 14   7.2   3.9
 13500  -3.0  26.6  245  22 11   6.1   3.4 |  -2.4  27.7  260  26 14   7.1   3.9
 13000  -1.7  28.9  240  21 11   6.6   3.6 |  -1.4  29.5  265  25 13   7.9   4.3
 12500  -0.8  30.6  240  20 10   6.7   3.7 |  -0.2  31.6  260  24 12   7.9   4.3
 12000   0.1  32.2  235  19 10   5.7   3.1 |   0.9  33.6  260  22 12   7.6   4.2
 11500   1.0  33.8  235  18  9   5.4   3.0 |   1.9  35.4  260  20 10   7.6   4.2
 11000   2.1  35.8  230  16  8   9.7   5.3 |   3.0  37.4  255  18  9   6.9   3.8
 10500   3.4  38.1  230  15  8   9.6   5.3 |   4.0  39.2  250  15  8   6.1   3.3
 10250   4.1  39.4  230  15  8   6.1   3.3 |   4.5  40.1  245  13  7  10.3   5.6
 10000   4.4  39.9  225  14  7   7.0   3.8 |   5.4  41.7  240  13  7  11.3   6.2
  9750   5.1  41.2  225  13  7  10.5   5.7 |   6.0  42.8  235  12  6   7.8   4.3
  9500   5.8  42.4  225  13  6   9.6   5.3 |   6.6  43.9  230  12  6   9.0   4.9
  9250   6.5  43.7  225  12  6   8.0   4.4 |   7.2  45.0  225  11  6   7.8   4.3
  9000   7.0  44.6  225  11  6   7.3   4.0 |   7.8  46.0  225  11  5   7.8   4.3
  8750   7.6  45.7  225  10  5   8.4   4.6 |   8.4  47.1  220  10  5   8.7   4.8
  8500   8.1  46.6  225  10  5   8.0   4.4 |   9.0  48.2  215  10  5   8.5   4.6
  8250   8.7  47.7  225   9  5   8.0   4.4 |   9.6  49.3  215  10  5   8.9   4.9
  8000   9.3  48.7  230   8  4   7.1   3.9 |  10.3  50.5  210  10  5   8.1   4.5
  7750   9.7  49.5  230   7  4   6.2   3.4 |  10.8  51.4  205   9  5   7.2   3.9
  7500  10.2  50.4  230   6  3   6.4   3.5 |  11.3  52.3  200   9  5   7.0   3.8
  7250  10.7  51.3  235   5  3   6.6   3.6 |  11.8  53.2  190   9  4   6.6   3.6
  7000  11.1  52.0  235   4  2   6.5   3.6 |  12.2  54.0  180   8  4   5.9   3.2
  6750  11.6  52.9  240   4  2   6.3   3.5 |  12.6  54.7  170   8  4   5.0   2.8
  6500  12.1  53.8  250   4  2   8.2   4.5 |  12.9  55.2  155   8  4   2.6   1.4
  6250  12.8  55.0  250   4  2   9.5   5.2 |  12.9  55.2  145   8  4   1.1   0.6
  6000  13.4  56.1  255   3  2   9.2   5.0 |  12.9  55.2  130   8  4   0.6   0.3
  5750  14.1  57.4  255   3  2   8.3   4.6 |  12.9  55.2  120   8  4   1.1   0.6
  5500  14.6  58.3  255   3  2   7.2   4.0 |  13.1  55.6  115   8  4   4.4   2.4
  5250  15.2  59.4  255   4  2   7.7   4.2 |  13.5  56.3  115   8  4   5.2   2.9
  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 0.000 sec
                   West Longitude: 108 deg 32 min 0.000 sec
                   Elevation: 4839 feet (1475 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.