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
000
UXUS97 KGJT 191226
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0626 MDT Tuesday, May 19, 2015

This forecast is for Tuesday, May 19, 2015:

If the trigger temperature of 57.6 F/14.2 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 219 ft/min (1.1 m/s)
   Maximum height of thermals.................. 12642 ft MSL (7803 ft AGL)

Forecast maximum temperature................... 64.0 F/18.2 C
Time of trigger temperature.................... 1100 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................. 9223 ft MSL (4384 ft AGL)
Thermal soaring outlook for Wednesday 05/20.... Fair

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

Remarks...

Sunrise/Sunset.................... 05:58:04 / 20:22:59 MDT
Total possible sunshine........... 14 hr 24 min 55 sec (864 min 55 sec)
Altitude of sun at 13:10:43 MDT... 70.69 degrees

Upper air data from rawinsonde observation taken on 05/19/2015 at 0600 MDT

Freezing level.................. 9812 ft MSL (4973 ft AGL)
Convective condensation level... 10279 ft MSL (5440 ft AGL)
Lifted condensation level....... 11416 ft MSL (6577 ft AGL)
Lifted index.................... +0.1
K index......................... +17.6

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  -54.9 -66.8   230   21   11   0.2   0.1  109.2 228.6    52.2      M    M
 45000  -55.1 -67.2   230   23   12   4.1   2.3   84.0 183.2    40.4      M    M
 40000  -54.0 -65.2   195   39   20  -1.7  -0.9   62.6 144.7    29.3      M    M
 38000  -53.8 -64.8   175   43   22   1.8   1.0   52.9 127.3    23.7      M    M
 36000  -54.2 -65.6   160   57   29   5.1   2.8   43.8 110.8    18.0      M    M
 34000  -52.0 -61.6   155   71   37   7.0   3.8   38.5 101.3    14.7      M    M
 32000  -48.1 -54.6   150   83   43   6.1   3.3   35.7  96.3    13.1      M    M
 30000  -43.6 -46.5   160   72   37   7.9   4.3   33.9  93.1    12.1      M    M
 29000  -40.8 -41.4   160   57   30   8.8   4.9   33.7  92.7    12.1      M    M
 28000  -38.8 -37.8   160   43   22   3.2   1.8   32.5  90.5    11.3      M    M
 27000  -36.5 -33.7   160   29   15   7.7   4.2   31.7  89.0    10.8      M    M
 26000  -34.2 -29.6   150   29   15   8.8   4.8   30.9  87.5    10.3      M    M
 25000  -32.0 -25.6   170   31   16   8.5   4.7   30.0  86.0     9.7      M    M
 24000  -29.1 -20.4   185   30   15   9.4   5.2   30.0  85.9     9.8      M    M
 23000  -26.6 -15.9   180   35   18   8.1   4.4   29.4  85.0     9.4      M    M
 22000  -24.9 -12.8   175   40   20   8.4   4.6   28.0  82.4     8.3      M    M
 21000  -22.3  -8.1   175   37   19   6.0   3.3   27.6  81.7     8.1      M    M
 20000  -19.7  -3.5   170   34   17  10.6   5.8   26.4  79.6     7.2      M    M
 19500  -18.3  -0.9   175   32   17   6.7   3.7   26.3  79.4     7.1      M    M
 19000  -17.5   0.5   180   31   16   5.4   3.0   25.6  78.1     6.5      M    M
 18500  -16.6   2.1   180   29   15   8.1   4.5   25.1  77.1     6.0      M    M
 18000  -15.4   4.3   180   27   14   8.0   4.4   24.7  76.5     5.8      M    M
 17500  -14.2   6.4   175   26   13   7.6   4.2   24.4  75.9     5.5      M    M
 17000  -13.1   8.4   180   24   12   7.6   4.1   24.0  75.3     5.2      M    M
 16500  -12.0  10.4   195   25   13   7.1   3.9   23.7  74.6     4.9      M    M
 16000  -11.2  11.8   205   28   14   5.9   3.2   22.9  73.1     4.2      M    M
 15500  -11.4  11.5   215   28   14  -2.2  -1.2   21.0  69.7     2.6      M    M
 15000  -10.3  13.5   225   29   15   8.6   4.7   20.6  69.1     2.3      M    M
 14500   -9.0  15.8   225   24   12   8.9   4.9   20.5  68.8     2.1      M    M
 14000   -7.6  18.3   230   19   10   8.9   4.9   20.3  68.6     2.0      M    M
 13500   -6.3  20.7   220   16    8   8.8   4.8   20.2  68.3     1.9      M    M
 13000   -5.1  22.8   205   15    8   3.6   2.0   19.9  67.9     1.6      M    M
 12500   -6.3  20.7   225   11    6  -5.1  -2.8   17.2  63.0    -1.0    632  3.2
 12000   -5.5  22.1   255    9    5   8.3   4.5   16.5  61.8    -1.7    592  3.0
 11500   -4.3  24.3   245    6    3   8.2   4.5   16.3  61.3    -2.0    542  2.8
 11000   -3.1  26.4   225    4    2   8.4   4.6   16.0  60.9    -2.3    492  2.5
 10500   -1.8  28.8   220    5    2   8.8   4.8   15.9  60.5    -2.5    438  2.2
 10250   -1.2  29.8   220    5    2   8.8   4.8   15.8  60.4    -2.6    411  2.1
 10000   -0.5  31.1   215    5    3   8.7   4.8   15.7  60.3    -2.7    385  2.0
  9750    0.1  32.2   205    6    3   8.6   4.7   15.6  60.1    -2.8    358  1.8
  9500    0.7  33.3   200    7    4   8.8   4.8   15.5  60.0    -2.9    332  1.7
  9250    1.4  34.5   195    9    4   8.0   4.4   15.4  59.8    -3.0    305  1.5
  9000    1.9  35.4   190   10    5   6.6   3.6   15.2  59.4    -3.2    282  1.4
  8750    2.4  36.3   185   12    6   6.4   3.5   15.0  59.0    -3.4    261  1.3
  8500    2.8  37.0   185   14    7   6.4   3.5   14.7  58.5    -3.7    239  1.2
  8250    3.3  37.9   180   16    8   6.4   3.5   14.5  58.0    -4.0    218  1.1
  8000    3.8  38.8   180   18    9   6.4   3.5   14.2  57.6    -4.3    197  1.0
  7750    4.2  39.6   175   18    9   6.5   3.6   13.9  57.1    -4.6    175  0.9
  7500    4.7  40.5   170   19   10   6.3   3.4   13.7  56.6    -4.8    154  0.8
  7250    5.1  41.2   160   20   10   7.1   3.9   13.4  56.2    -5.1    133  0.7
  7000    5.7  42.3   155   21   11   8.0   4.4   13.3  55.9    -5.3    108  0.5
  6750    6.3  43.3   155   22   11   7.8   4.3   13.1  55.6    -5.4     83  0.4
  6500    6.9  44.4   155   22   11   8.2   4.5   13.0  55.4    -5.6     58  0.3
  6250    7.4  45.3   150   23   12   3.1   1.7   12.8  55.0    -5.8     36  0.2
  6000    7.4  45.3   150   24   12   1.8   1.0   12.1  53.8    -6.6     28  0.1
  5750    7.8  46.0   150   21   11   7.9   4.3   11.7  53.1    -7.0     10  0.1
  5500    8.4  47.1   145   17    9   9.3   5.1   11.7  53.0    -7.1      M    M
  5250    9.0  48.2   140   13    7   8.8   4.8   11.6  52.9    -7.2      M    M
  5000    9.7  49.5   135   10    5   9.3   5.1   11.6  52.8    -7.3      M    M

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

           05/19/2015 at 0900 MDT          |       05/19/2015 at 1200 MDT
                                           |
K index... +23.3  LI... +272.9             | K index... +23.1  LI... +271.3
CAPE... +120.9  CIN... -16.0               | CAPE... +347.4  CIN... -0.2
                                           |
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 -55.6 -68.1  245  25 13   2.0   1.1 | -55.4 -67.7  240  22 11   1.9   1.0
 45000 -52.5 -62.5  235  29 15   1.8   1.0 | -52.3 -62.1  240  31 16   2.0   1.1
 40000 -49.8 -57.6  210  32 16   1.8   1.0 | -49.3 -56.7  230  34 18   2.0   1.1
 38000 -49.2 -56.6  200  31 16   0.4   0.2 | -48.6 -55.5  225  32 17   0.5   0.3
 36000 -48.9 -56.0  190  29 15   0.4   0.2 | -48.4 -55.1  220  27 14   0.5   0.3
 34000 -48.5 -55.3  180  29 15   2.7   1.5 | -48.0 -54.4  210  24 12   2.4   1.3
 32000 -47.0 -52.6  170  32 17   2.5   1.4 | -46.7 -52.1  200  21 11   2.1   1.2
 30000 -44.7 -48.5  165  35 18   6.6   3.6 | -44.6 -48.3  185  18  9   6.1   3.4
 29000 -42.7 -44.9  165  33 17   6.7   3.7 | -42.7 -44.9  170  19 10   6.3   3.4
 28000 -40.7 -41.3  165  32 17   6.7   3.7 | -40.9 -41.6  155  21 11   6.3   3.4
 27000 -38.6 -37.5  165  31 16   8.0   4.4 | -39.0 -38.2  145  25 13   7.8   4.3
 26000 -36.0 -32.8  165  26 13   8.8   4.8 | -36.3 -33.3  145  23 12   8.9   4.9
 25000 -33.4 -28.1  165  21 11   8.8   4.8 | -33.6 -28.5  155  21 11   8.9   4.9
 24000 -30.7 -23.3  165  16  8   8.5   4.7 | -31.0 -23.8  160  20 10   8.5   4.7
 23000 -28.4 -19.1  175  16  8   7.8   4.3 | -28.7 -19.7  175  17  9   7.6   4.2
 22000 -26.1 -15.0  185  17  9   7.8   4.3 | -26.4 -15.5  195  15  8   7.6   4.2
 21000 -23.7 -10.7  195  19 10   7.6   4.2 | -24.2 -11.6  215  15  8   7.6   4.2
 20000 -21.4  -6.5  200  17  9   7.6   4.1 | -21.9  -7.4  220  16  8   7.6   4.2
 19500 -20.3  -4.5  205  16  8   7.6   4.1 | -20.8  -5.4  225  16  8   7.6   4.2
 19000 -19.2  -2.6  210  16  8   7.5   4.1 | -19.7  -3.5  230  17  9   7.6   4.2
 18500 -18.0  -0.4  215  15  8   6.6   3.6 | -18.5  -1.3  230  17  9   7.3   4.0
 18000 -17.2   1.0  215  14  7   5.8   3.2 | -17.5   0.5  230  18  9   7.0   3.8
 17500 -16.3   2.7  215  12  6   5.8   3.2 | -16.5   2.3  230  19 10   7.0   3.8
 17000 -15.5   4.1  215  12  6   4.7   2.6 | -15.5   4.1  230  20 10   6.8   3.7
 16500 -14.8   5.4  215  12  6   4.8   2.6 | -14.5   5.9  230  20 10   6.8   3.7
 16000 -14.1   6.6  215  12  6   6.4   3.5 | -13.4   7.9  230  21 11   6.9   3.8
 15500 -13.1   8.4  215  13  7   6.7   3.7 | -12.4   9.7  230  21 11   6.9   3.8
 15000 -12.2  10.0  215  14  7   7.4   4.0 | -11.4  11.5  230  22 11   6.9   3.8
 14500 -11.0  12.2  220  15  8   7.9   4.4 |  -9.9  14.2  230  23 12   6.9   3.8
 14000  -9.3  15.3  225  16  8   8.0   4.4 |  -8.9  16.0  235  23 12   7.1   3.9
 13500  -8.1  17.4  230  17  9   8.0   4.4 |  -7.9  17.8  235  23 12   7.2   3.9
 13000  -7.0  19.4  235  18  9   8.4   4.6 |  -6.8  19.8  240  22 11   7.0   3.9
 12500  -5.7  21.7  235  17  9   8.6   4.7 |  -5.8  21.6  240  21 11   7.0   3.8
 12000  -4.5  23.9  240  17  9   7.9   4.3 |  -4.8  23.4  240  21 11   7.1   3.9
 11500  -3.5  25.7  240  15  8   7.7   4.2 |  -3.8  25.2  245  20 10   7.2   3.9
 11000  -2.4  27.7  240  13  7   6.6   3.6 |  -2.8  27.0  245  19 10   6.3   3.5
 10500  -1.5  29.3  240  12  6   5.5   3.0 |  -1.9  28.6  245  16  8   5.3   2.9
 10250  -1.1  30.0  240  11  6   9.3   5.1 |  -1.5  29.3  245  15  8   8.8   4.9
 10000  -0.2  31.6  235  11  5  10.4   5.7 |  -0.7  30.7  245  14  7  10.0   5.5
  9750   0.4  32.7  235  10  5   7.3   4.0 |  -0.1  31.8  245  12  6   7.3   4.0
  9500   1.0  33.8  235  10  5   8.3   4.5 |   0.4  32.7  250  11  5   8.0   4.4
  9250   1.6  34.9  240  10  5   7.4   4.1 |   1.0  33.8  250   9  5   8.2   4.5
  9000   2.1  35.8  240  10  5   8.1   4.4 |   1.6  34.9  250   8  4   9.7   5.3
  8750   2.8  37.0  240  10  5   9.1   5.0 |   2.3  36.1  250   8  4  10.4   5.7
  8500   3.4  38.1  235  11  6   8.8   4.8 |   3.1  37.6  255   8  4  10.1   5.5
  8250   4.1  39.4  235  11  6   9.0   4.9 |   3.8  38.8  255   7  4  10.8   5.9
  8000   4.7  40.5  230  12  6   7.4   4.0 |   4.7  40.5  255   7  4  10.7   5.9
  7750   5.2  41.4  220  12  6   5.4   3.0 |   5.4  41.7  255   7  4   9.7   5.3
  7500   5.5  41.9  210  12  6   5.0   2.8 |   6.1  43.0  255   7  4   9.8   5.4
  7250   5.9  42.6  200  11  6   4.4   2.4 |   6.9  44.4  255   7  4   9.9   5.4
  7000   6.2  43.2  190  11  6   4.8   2.6 |   7.6  45.7  260   7  4  10.0   5.5
  6750   6.5  43.7  185  11  5   5.5   3.0 |   8.4  47.1  260   7  4  10.0   5.5
  6500   7.0  44.6  180  10  5   8.6   4.7 |   9.1  48.4  260   7  3  10.7   5.8
  6250   7.8  46.0  180  10  5  11.0   6.1 |   9.9  49.8  260   7  3  11.6   6.4
  6000   8.5  47.3  180   9  5  10.0   5.5 |  10.8  51.4  260   6  3  10.5   5.8
  5750   9.3  48.7  180   9  5   9.7   5.3 |  11.5  52.7  260   6  3  11.3   6.2
  5500  10.0  50.0  180   9  4  10.1   5.5 |  12.5  54.5  260   6  3  14.9   8.2
  5250  10.7  51.3  180   8  4  10.7   5.9 |  13.7  56.7  265   6  3  16.4   9.0
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/19/2015 at 1500 MDT          |       05/19/2015 at 1800 MDT
                                           |
K index... +24.2  LI... +271.9             | K index... +25.3  LI... +270.8
CAPE... +206.4  CIN... -16.5               | CAPE... +362.8  CIN... -4.5
                                           |
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 -55.1 -67.2  235  21 11   2.0   1.1 | -55.0 -67.0  240  21 11   2.5   1.4
 45000 -51.9 -61.4  240  31 16   1.3   0.7 | -51.3 -60.3  245  34 18   0.3   0.2
 40000 -49.9 -57.8  240  32 17   1.4   0.8 | -50.6 -59.1  250  38 20   0.4   0.2
 38000 -49.3 -56.7  240  32 16   0.8   0.4 | -50.1 -58.2  250  36 19   1.1   0.6
 36000 -48.8 -55.8  235  30 15   0.8   0.4 | -49.4 -56.9  250  31 16   1.1   0.6
 34000 -48.3 -54.9  235  28 14   1.5   0.8 | -48.6 -55.5  250  27 14   2.8   1.5
 32000 -47.4 -53.3  225  22 11   1.4   0.8 | -46.9 -52.4  245  22 11   2.6   1.4
 30000 -45.4 -49.7  210  18  9   8.1   4.5 | -44.6 -48.3  240  20 10   7.0   3.8
 29000 -42.9 -45.2  210  17  9   8.3   4.6 | -42.4 -44.3  240  20 10   7.1   3.9
 28000 -40.4 -40.7  210  17  9   8.3   4.6 | -40.3 -40.5  235  20 10   7.1   3.9
 27000 -37.9 -36.2  210  17  9   8.4   4.6 | -38.1 -36.6  235  20 10   8.0   4.4
 26000 -35.4 -31.7  215  17  9   8.4   4.6 | -35.6 -32.1  240  20 10   8.4   4.6
 25000 -32.9 -27.2  220  18  9   8.4   4.6 | -33.1 -27.6  240  20 10   8.4   4.6
 24000 -30.3 -22.5  225  19 10   8.2   4.5 | -30.6 -23.1  245  20 10   8.3   4.6
 23000 -28.0 -18.4  230  19 10   7.7   4.2 | -28.1 -18.6  245  20 10   8.3   4.5
 22000 -25.8 -14.4  230  20 10   7.7   4.2 | -25.6 -14.1  250  20 10   8.3   4.5
 21000 -23.5 -10.3  235  20 10   7.5   4.1 | -23.2  -9.8  250  20 10   7.4   4.1
 20000 -21.3  -6.3  235  21 11   7.4   4.1 | -21.0  -5.8  255  21 11   7.3   4.0
 19500 -20.2  -4.4  240  22 11   7.4   4.1 | -20.0  -4.0  255  22 11   7.3   4.0
 19000 -19.1  -2.4  240  22 11   7.4   4.1 | -18.9  -2.0  255  22 12   7.3   4.0
 18500 -18.0  -0.4  240  22 12   6.8   3.7 | -17.8  -0.0  255  23 12   7.0   3.9
 18000 -17.0   1.4  240  23 12   6.4   3.5 | -16.8   1.8  255  24 12   6.9   3.8
 17500 -16.1   3.0  245  25 13   6.4   3.5 | -15.8   3.6  255  25 13   6.9   3.8
 17000 -15.1   4.8  245  26 13   6.8   3.7 | -14.7   5.5  255  25 13   7.7   4.2
 16500 -14.1   6.6  245  27 14   6.8   3.7 | -13.6   7.5  255  26 13   7.7   4.2
 16000 -13.1   8.4  250  27 14   7.0   3.8 | -12.5   9.5  260  26 13   7.6   4.2
 15500 -12.1  10.2  250  27 14   7.0   3.9 | -11.3  11.7  260  25 13   7.6   4.2
 15000 -11.0  12.2  250  28 14   7.4   4.0 |  -9.7  14.5  255  24 13   7.7   4.2
 14500  -9.4  15.1  255  27 14   7.7   4.2 |  -8.6  16.5  255  24 12   7.7   4.2
 14000  -8.2  17.2  255  26 13   8.0   4.4 |  -7.4  18.7  255  23 12   7.7   4.2
 13500  -7.1  19.2  255  25 13   8.1   4.4 |  -6.3  20.7  250  21 11   7.7   4.2
 13000  -5.9  21.4  250  24 12   7.9   4.3 |  -5.2  22.6  250  20 10   7.8   4.3
 12500  -4.8  23.4  250  22 11   7.9   4.3 |  -4.1  24.6  245  19 10   7.9   4.3
 12000  -3.6  25.5  245  21 11   7.6   4.1 |  -2.9  26.8  240  17  9   8.3   4.6
 11500  -2.6  27.3  245  19 10   7.5   4.1 |  -1.7  28.9  235  16  8   8.5   4.6
 11000  -1.5  29.3  240  17  9   6.5   3.5 |  -0.4  31.3  230  15  8   8.4   4.6
 10500  -0.6  30.9  235  16  8   5.3   2.9 |   0.8  33.4  225  15  8   7.7   4.2
 10250  -0.2  31.6  230  15  8   9.3   5.1 |   1.5  34.7  225  14  7  11.3   6.2
 10000   0.6  33.1  230  14  7   9.6   5.3 |   2.4  36.3  220  14  7  12.1   6.6
  9750   1.1  34.0  225  14  7   5.7   3.1 |   3.2  37.8  220  14  7   9.0   4.9
  9500   1.6  34.9  220  13  7   6.9   3.8 |   3.9  39.0  220  14  7   9.9   5.5
  9250   2.1  35.8  215  13  7   6.2   3.4 |   4.6  40.3  215  13  7   9.2   5.0
  9000   2.5  36.5  210  12  6   7.2   4.0 |   5.2  41.4  215  13  7   8.9   4.9
  8750   3.1  37.6  210  12  6   8.4   4.6 |   5.9  42.6  210  12  6   9.3   5.1
  8500   3.7  38.7  205  11  6   8.0   4.4 |   6.6  43.9  205  12  6   9.2   5.0
  8250   4.3  39.7  200  11  6   8.4   4.6 |   7.3  45.1  205  12  6   9.2   5.0
  8000   5.0  41.0  195  11  5   8.2   4.5 |   7.9  46.2  200  11  6   8.8   4.8
  7750   5.5  41.9  190  10  5   7.5   4.1 |   8.5  47.3  195  10  5   8.5   4.6
  7500   6.1  43.0  190  10  5   7.6   4.2 |   9.2  48.6  195  10  5   8.7   4.8
  7250   6.6  43.9  185  10  5   8.0   4.4 |   9.8  49.6  190   9  5   9.8   5.4
  7000   7.2  45.0  180  10  5   8.1   4.4 |  10.6  51.1  190   9  5  10.2   5.6
  6750   7.8  46.0  180  10  5   7.5   4.1 |  11.3  52.3  190   9  4   9.4   5.2
  6500   8.3  46.9  175  10  5   8.2   4.5 |  12.0  53.6  185   8  4   9.9   5.4
  6250   8.9  48.0  175  10  5   9.2   5.0 |  12.8  55.0  185   8  4  10.7   5.9
  6000   9.6  49.3  175   9  5   8.6   4.7 |  13.6  56.5  185   8  4  10.4   5.7
  5750  10.2  50.4  170   9  5   9.0   4.9 |  14.3  57.7  185   8  4   9.8   5.4
  5500  10.9  51.6  175   9  5  10.4   5.7 |  15.0  59.0  185   7  4   9.5   5.2
  5250  11.6  52.9  175   9  4  11.1   6.1 |  15.7  60.3  190   7  4   9.8   5.4
  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.

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.