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 15 16
000
UXUS97 KGJT 151412
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0712 MST Wednesday, November 15, 2017

This forecast is for Wednesday, November 15, 2017:

If the trigger temperature of 60.4 F/15.8 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 211 ft/min (1.1 m/s)
   Maximum height of thermals.................. 10141 ft MSL (5302 ft AGL)

Forecast maximum temperature................... 61.0 F/16.6 C
Time of trigger temperature.................... 1330 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 7335 ft MSL (2496 ft AGL)
Thermal soaring outlook for Thursday 11/16..... Fair

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

Remarks...

Sunrise/Sunset.................... 06:57:44 / 16:59:45 MST
Total possible sunshine........... 10 hr 2 min 1 sec (602 min 1 sec)
Altitude of sun at 11:58:56 MST... 32.25 degrees

Upper air data from rawinsonde observation taken on 11/15/2017 at 0500 MST

Freezing level.................. 10224 ft MSL (5385 ft AGL)
Convective condensation level... 20923 ft MSL (16084 ft AGL)
Lifted condensation level....... 15751 ft MSL (10912 ft AGL)
Lifted index.................... +10.1
K index......................... -34.7

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  -65.0 -85.0   280   95   49   2.5   1.4   92.6 198.7    43.5      M    M
 45000  -60.6 -77.1   275  113   58  -2.4  -1.3   75.1 167.2    36.0      M    M
 40000  -58.3 -72.9   280  105   54  -1.0  -0.5   54.5 130.0    25.2      M    M
 38000  -57.7 -71.9   285   90   46   5.1   2.8   46.6 116.0    20.6      M    M
 36000  -56.6 -69.9   290   75   39   9.4   5.2   39.7 103.4    16.3      M    M
 34000  -51.2 -60.2   285   74   38   8.7   4.8   39.0 102.1    16.2      M    M
 32000  -46.0 -50.8   285   72   37   8.7   4.8   38.1 100.6    16.0      M    M
 30000  -40.1 -40.2   280   67   34   4.2   2.3   37.3  99.2    15.9      M    M
 29000  -38.6 -37.5   280   65   33  10.1   5.6   35.4  95.7    14.6      M    M
 28000  -35.8 -32.4   275   63   32   9.5   5.2   35.3  95.5    14.7      M    M
 27000  -32.9 -27.2   275   61   32   9.4   5.1   35.2  95.4    14.9      M    M
 26000  -30.2 -22.4   270   60   31   8.3   4.5   35.0  95.1    14.9      M    M
 25000  -28.1 -18.6   270   58   30   7.9   4.3   33.9  93.1    14.2      M    M
 24000  -26.1 -15.0   270   55   28   8.8   4.8   32.9  91.1    13.4      M    M
 23000  -23.3  -9.9   270   54   28   9.1   5.0   32.6  90.7    13.4      M    M
 22000  -20.6  -5.1   270   54   28   7.7   4.2   32.4  90.4    13.4      M    M
 21000  -18.9  -2.0   275   47   24   5.2   2.9   31.0  87.8    12.4      M    M
 20000  -17.4   0.7   280   40   21   6.3   3.5   29.4  84.9    11.1      M    M
 19500  -16.6   2.1   285   38   19   5.4   3.0   28.7  83.6    10.5      M    M
 19000  -15.2   4.6   290   35   18  10.4   5.7   28.5  83.3    10.5      M    M
 18500  -13.8   7.2   285   34   17  10.9   6.0   28.4  83.2    10.5      M    M
 18000  -13.3   8.1   275   32   16  -1.3  -0.7   27.3  81.1     9.6      M    M
 17500  -12.7   9.1   265   31   16   4.3   2.4   26.3  79.3     8.9      M    M
 17000  -11.7  10.9   255   31   16   7.3   4.0   25.7  78.3     8.4      M    M
 16500  -10.6  12.9   255   30   15   7.2   4.0   25.3  77.6     8.1      M    M
 16000   -9.0  15.8   255   28   14   7.2   4.0   24.7  76.5     7.6      M    M
 15500   -7.9  17.8   250   26   14   7.2   4.0   24.2  75.6     7.2      M    M
 15000   -6.9  19.6   250   25   13   7.2   4.0   23.8  74.8     6.9      M    M
 14500   -5.8  21.6   245   24   12   7.2   4.0   23.4  74.1     6.6      M    M
 14000   -4.7  23.5   245   23   12   7.2   4.0   23.0  73.4     6.2      M    M
 13500   -3.6  25.5   245   22   11   7.2   4.0   22.5  72.6     5.8      M    M
 13000   -2.6  27.3   245   20   10   7.8   4.3   22.1  71.8     5.5      M    M
 12500   -1.8  28.8   240   19   10   0.7   0.4   21.3  70.3     4.8      M    M
 12000   -1.7  28.9   240   17    9  -2.3  -1.3   19.9  67.8     3.5      M    M
 11500   -2.0  28.4   240   10    5   5.0   2.7   18.0  64.4     1.7      M    M
 11000   -1.5  29.3   225    3    2   1.6   0.9   17.1  62.8     0.8      M    M
 10500   -0.7  30.7   180    4    2   9.4   5.2   16.5  61.8     0.1      M    M
 10250   -0.0  32.0   170    5    3   8.8   4.8   16.5  61.6     0.0      M    M
 10000    0.6  33.1   170    5    2   9.0   5.0   16.4  61.5    -0.0    394  2.0
  9750    1.3  34.3   165    5    2   9.0   4.9   16.3  61.4    -0.1    367  1.9
  9500    2.0  35.6   160    4    2   9.0   4.9   16.3  61.3    -0.2    339  1.7
  9250    2.6  36.7   160    4    2   8.9   4.9   16.2  61.2    -0.2    312  1.6
  9000    3.3  37.9   155    4    2   9.1   5.0   16.2  61.1    -0.3    285  1.4
  8750    4.0  39.2   140    5    2   8.4   4.6   16.1  61.0    -0.3    257  1.3
  8500    4.5  40.1   130    6    3   4.7   2.6   15.9  60.6    -0.6    234  1.2
  8250    4.7  40.5   125    7    3   2.7   1.5   15.4  59.7    -1.1    220  1.1
  8000    4.9  40.8   120    8    4   3.2   1.8   14.9  58.7    -1.6    206  1.0
  7750    5.2  41.4   120    8    4   3.1   1.7   14.3  57.8    -2.1    192  1.0
  7500    5.4  41.7   120    8    4   3.1   1.7   13.8  56.9    -2.6    178  0.9
  7250    5.6  42.1   120    9    4   3.1   1.7   13.3  55.9    -3.1    163  0.8
  7000    5.8  42.4   120    9    5   2.9   1.6   12.8  55.0    -3.6    149  0.8
  6750    6.1  43.0   120    9    5   3.8   2.1   12.3  54.1    -4.1    135  0.7
  6500    6.5  43.7   120    9    4   6.7   3.7   11.9  53.5    -4.5    116  0.6
  6250    7.0  44.6   115    8    4   8.1   4.5   11.8  53.2    -4.6     91  0.5
  6000    7.6  45.7   115    8    4   7.4   4.0   11.6  53.0    -4.8     66  0.3
  5750    8.2  46.8   115    8    4   9.0   4.9   11.5  52.7    -4.9     41  0.2
  5500    8.8  47.8   115    8    4   3.2   1.8   11.3  52.4    -5.1     16  0.1
  5250    8.2  46.8   120    8    4 -19.8 -10.9   10.1  50.1    -6.4     26  0.1
  5000    5.9  42.6   120    8    4 -40.5 -22.2    7.0  44.5    -9.5     90  0.5

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

           11/15/2017 at 0800 MST          |       11/15/2017 at 1100 MST
                                           |
K index... -9.8  LI... +6.5                | K index... -4.9  LI... +5.0
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -66.1 -87.0  280  92 47   2.2   1.2 | -66.3 -87.3  280  93 48   2.7   1.5
 45000 -62.8 -81.0  285 107 55   2.4   1.3 | -62.3 -80.1  285 102 53   1.8   1.0
 40000 -59.1 -74.4  285 101 52   2.3   1.3 | -59.3 -74.7  285 100 51   1.8   1.0
 38000 -56.4 -69.5  285  90 46   5.0   2.8 | -56.5 -69.7  280  89 46   5.5   3.0
 36000 -53.4 -64.1  285  78 40   5.0   2.8 | -53.1 -63.6  280  77 40   5.5   3.0
 34000 -49.6 -57.3  280  69 35   8.2   4.5 | -49.3 -56.7  275  67 35   7.7   4.2
 32000 -44.7 -48.5  285  64 33   8.2   4.5 | -44.6 -48.3  275  62 32   7.7   4.2
 30000 -39.8 -39.6  280  60 31   8.1   4.4 | -40.0 -40.0  275  58 30   8.0   4.4
 29000 -37.4 -35.3  280  59 30   8.1   4.4 | -37.6 -35.7  275  56 29   8.0   4.4
 28000 -34.9 -30.8  280  57 30   8.1   4.4 | -35.2 -31.4  275  55 28   8.0   4.4
 27000 -32.0 -25.6  280  56 29   7.5   4.1 | -32.3 -26.1  275  54 28   7.5   4.1
 26000 -29.8 -21.6  280  54 28   7.5   4.1 | -30.1 -22.2  275  53 27   7.5   4.1
 25000 -27.6 -17.7  280  53 27   7.5   4.1 | -27.9 -18.2  275  52 27   7.5   4.1
 24000 -25.4 -13.7  280  51 26   7.1   3.9 | -25.6 -14.1  275  51 26   7.3   4.0
 23000 -23.2  -9.8  280  49 25   7.1   3.9 | -23.5 -10.3  275  48 25   7.3   4.0
 22000 -21.1  -6.0  280  46 24   7.2   3.9 | -21.3  -6.3  275  45 23   7.3   4.0
 21000 -18.9  -2.0  275  44 23   7.8   4.3 | -19.1  -2.4  270  42 22   7.5   4.1
 20000 -16.6   2.1  275  41 21   7.8   4.3 | -16.9   1.6  270  40 21   7.5   4.1
 19500 -15.4   4.3  275  40 20   7.8   4.3 | -15.8   3.6  270  39 20   7.5   4.1
 19000 -14.3   6.3  275  38 20   7.8   4.3 | -14.7   5.5  265  38 20   7.5   4.1
 18500 -13.1   8.4  275  37 19   7.3   4.0 | -13.5   7.7  265  38 19   7.8   4.3
 18000 -12.0  10.4  270  36 19   7.3   4.0 | -12.4   9.7  265  37 19   7.7   4.2
 17500 -10.9  12.4  270  35 18   7.1   3.9 | -11.2  11.8  265  37 19   7.7   4.2
 17000  -9.8  14.4  270  34 18   7.0   3.8 | -10.0  14.0  265  36 19   7.7   4.2
 16500  -8.8  16.2  265  34 17   6.8   3.7 |  -8.9  16.0  265  36 18   7.4   4.1
 16000  -7.8  18.0  265  33 17   6.0   3.3 |  -7.8  18.0  265  35 18   6.4   3.5
 15500  -6.9  19.6  265  32 16   6.2   3.4 |  -6.8  19.8  265  34 17   6.7   3.6
 15000  -6.1  21.0  260  30 16   4.1   2.2 |  -5.9  21.4  260  32 17   5.0   2.7
 14500  -5.5  22.1  260  29 15   4.3   2.3 |  -5.2  22.6  260  31 16   5.1   2.8
 14000  -4.9  23.2  260  28 14   4.4   2.4 |  -4.4  24.1  260  29 15   4.4   2.4
 13500  -4.3  24.3  255  27 14   4.5   2.5 |  -3.9  25.0  255  27 14   4.4   2.4
 13000  -3.2  26.2  250  25 13   6.5   3.6 |  -2.8  27.0  250  25 13   5.9   3.2
 12500  -2.3  27.9  250  23 12   6.4   3.5 |  -2.0  28.4  250  24 12   5.7   3.1
 12000  -1.4  29.5  245  21 11   6.9   3.8 |  -1.1  30.0  245  23 12   7.6   4.2
 11500  -0.3  31.5  240  18  9   6.8   3.8 |   0.0  32.0  245  21 11   7.5   4.1
 11000   0.7  33.3  230  15  8   7.3   4.0 |   1.1  34.0  240  20 10   7.5   4.1
 10500   1.8  35.2  220  13  7   7.5   4.1 |   2.3  36.1  235  18  9   7.6   4.1
 10250   2.3  36.1  215  12  6   3.1   1.7 |   2.8  37.0  235  17  9   4.7   2.6
 10000   2.4  36.3  210  12  6   4.5   2.5 |   3.1  37.6  235  17  9   5.7   3.1
  9750   3.0  37.4  205  12  6   9.0   4.9 |   3.7  38.7  230  16  8   8.7   4.8
  9500   3.6  38.5  205  12  6   7.6   4.1 |   4.3  39.7  225  15  8   7.8   4.3
  9250   4.1  39.4  200  12  6   5.8   3.2 |   4.8  40.6  225  15  8   5.8   3.2
  9000   4.5  40.1  195  13  6   4.8   2.6 |   5.2  41.4  220  15  8   5.1   2.8
  8750   4.9  40.8  185  13  7   5.5   3.0 |   5.7  42.3  220  15  8   6.5   3.6
  8500   5.3  41.5  180  14  7   4.9   2.7 |   6.1  43.0  215  15  7   5.3   2.9
  8250   5.6  42.1  175  14  7   4.1   2.3 |   6.4  43.5  210  14  7   3.6   2.0
  8000   5.9  42.6  175  14  7   3.3   1.8 |   6.7  44.1  205  14  7   2.6   1.4
  7750   6.1  43.0  170  14  7   2.6   1.4 |   6.8  44.2  195  14  7   2.0   1.1
  7500   6.2  43.2  170  14  7   0.2   0.1 |   7.0  44.6  185  14  7   1.5   0.8
  7250   6.1  43.0  165  13  7  -1.8  -1.0 |   7.0  44.6  180  12  6   1.3   0.7
  7000   6.0  42.8  160  12  6  -0.8  -0.4 |   7.1  44.8  175  11  5   1.1   0.6
  6750   5.9  42.6  155  11  6  -4.1  -2.3 |   7.3  45.1  165   8  4   3.3   1.8
  6500   5.4  41.7  150  10  5  -9.3  -5.1 |   7.7  45.9  160   7  3   7.9   4.3
  6250   4.6  40.3  140   9  5 -12.1  -6.7 |   8.4  47.1  160   6  3   9.8   5.4
  6000   3.8  38.8  125   8  4  -6.1  -3.4 |   9.0  48.2  160   5  3   7.9   4.3
  5750   3.5  38.3  110   8  4  -8.5  -4.7 |   9.6  49.3  160   5  2   9.0   4.9
  5500   2.4  36.3  105   7  4 -17.7  -9.7 |  10.4  50.7  160   5  2  11.7   6.4
  5250   1.2  34.2  095   6  3 -10.3  -5.7 |  11.2  52.2  160   4  2   9.5   5.2
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           11/15/2017 at 1400 MST          |       11/15/2017 at 1700 MST
                                           |
K index... -0.9  LI... +4.8                | K index... +3.0  LI... +4.6
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -66.5 -87.7  280  97 50   2.9   1.6 | -66.9 -88.4  280 100 51   3.4   1.8
 45000 -62.2 -80.0  280 104 54   2.3   1.3 | -62.0 -79.6  280 106 55   2.4   1.3
 40000 -58.5 -73.3  280  99 51   2.3   1.3 | -58.0 -72.4  285  88 45   2.5   1.4
 38000 -55.9 -68.6  280  88 45   4.8   2.6 | -55.7 -68.3  285  81 42   4.4   2.4
 36000 -53.0 -63.4  275  76 39   4.8   2.6 | -53.1 -63.6  280  76 39   4.4   2.4
 34000 -49.3 -56.7  275  67 35   8.3   4.5 | -49.4 -56.9  280  71 37   8.6   4.7
 32000 -44.4 -47.9  275  65 33   8.3   4.5 | -44.3 -47.7  275  68 35   8.6   4.7
 30000 -39.6 -39.3  275  60 31   7.5   4.1 | -39.4 -38.9  275  64 33   7.4   4.0
 29000 -37.3 -35.1  275  57 30   7.5   4.1 | -37.2 -35.0  275  61 32   7.4   4.0
 28000 -35.1 -31.2  270  54 28   7.6   4.1 | -35.0 -31.0  275  58 30   7.4   4.0
 27000 -32.3 -26.1  270  51 26   7.8   4.3 | -32.8 -27.0  275  55 28   7.7   4.2
 26000 -29.9 -21.8  270  50 26   7.9   4.3 | -29.9 -21.8  270  52 27   7.8   4.3
 25000 -27.6 -17.7  270  48 25   7.9   4.3 | -27.6 -17.7  270  50 26   7.8   4.3
 24000 -25.3 -13.5  265  47 24   7.1   3.9 | -25.3 -13.5  270  48 25   7.6   4.2
 23000 -23.2  -9.8  265  47 24   7.1   3.9 | -23.1  -9.6  265  47 24   7.6   4.2
 22000 -21.1  -6.0  265  46 24   7.2   3.9 | -20.8  -5.4  265  46 24   7.6   4.2
 21000 -19.0  -2.2  265  45 23   7.1   3.9 | -18.6  -1.5  265  45 23   6.6   3.6
 20000 -16.8   1.8  265  44 22   7.1   3.9 | -16.7   1.9  260  43 22   6.6   3.6
 19500 -15.7   3.7  260  43 22   7.1   3.9 | -15.7   3.7  260  43 22   6.7   3.7
 19000 -14.7   5.5  260  42 22   7.1   3.9 | -14.7   5.5  260  42 22   6.8   3.7
 18500 -13.6   7.5  260  41 21   7.0   3.8 | -13.8   7.2  260  41 21   5.0   2.7
 18000 -12.6   9.3  260  40 21   7.0   3.8 | -13.0   8.6  260  40 20   5.2   2.8
 17500 -11.6  11.1  260  39 20   7.0   3.9 | -12.3   9.9  260  38 20   5.7   3.1
 17000 -10.5  13.1  260  38 19   7.0   3.9 | -11.4  11.5  260  37 19   6.1   3.4
 16500  -9.4  15.1  260  37 19   7.0   3.8 | -10.4  13.3  255  35 18   6.3   3.4
 16000  -8.4  16.9  260  35 18   6.7   3.7 |  -9.4  15.1  255  34 17   7.6   4.2
 15500  -7.4  18.7  260  33 17   6.8   3.7 |  -8.2  17.2  255  32 17   7.6   4.1
 15000  -6.4  20.5  260  31 16   5.9   3.3 |  -7.2  19.0  255  31 16   6.7   3.7
 14500  -5.5  22.1  260  29 15   6.0   3.3 |  -6.2  20.8  250  30 15   6.7   3.7
 14000  -4.7  23.5  260  27 14   5.5   3.0 |  -5.1  22.8  250  29 15   6.8   3.8
 13500  -3.9  25.0  255  26 13   5.4   2.9 |  -4.1  24.6  250  28 15   7.0   3.8
 13000  -2.7  27.1  250  25 13   6.1   3.3 |  -2.6  27.3  245  28 14   7.3   4.0
 12500  -1.9  28.6  245  25 13   5.9   3.2 |  -1.6  29.1  240  27 14   7.2   4.0
 12000  -0.9  30.4  240  25 13   7.7   4.2 |  -0.4  31.3  235  27 14   8.3   4.6
 11500   0.2  32.4  240  25 13   7.7   4.2 |   0.8  33.4  230  26 13   8.4   4.6
 11000   1.3  34.3  235  24 12   7.6   4.2 |   2.0  35.6  225  25 13   7.9   4.3
 10500   2.5  36.5  230  22 11   8.2   4.5 |   3.2  37.8  220  24 12   8.6   4.7
 10250   3.0  37.4  225  21 11   5.1   2.8 |   3.7  38.7  220  24 12   5.0   2.7
 10000   3.3  37.9  225  20 10   5.4   2.9 |   4.0  39.2  220  23 12   5.9   3.2
  9750   3.9  39.0  225  19 10   8.6   4.7 |   4.7  40.5  215  22 11  10.0   5.5
  9500   4.5  40.1  225  18  9   7.8   4.3 |   5.4  41.7  215  21 11   9.3   5.1
  9250   5.1  41.2  225  17  9   7.5   4.1 |   6.1  43.0  215  21 11   7.4   4.1
  9000   5.6  42.1  220  16  8   6.3   3.4 |   6.5  43.7  210  20 10   6.2   3.4
  8750   6.0  42.8  220  14  7   5.9   3.2 |   7.1  44.8  210  18  9   7.5   4.1
  8500   6.5  43.7  220  12  6   5.8   3.2 |   7.6  45.7  205  17  9   7.0   3.9
  8250   6.9  44.4  215  11  5   4.8   2.6 |   8.1  46.6  205  16  8   6.8   3.7
  8000   7.2  45.0  215   9  4   4.6   2.5 |   8.6  47.5  205  14  7   5.8   3.2
  7750   7.6  45.7  215   7  4   4.3   2.4 |   9.0  48.2  200  13  6   5.2   2.9
  7500   7.9  46.2  210   5  3   6.1   3.3 |   9.4  48.9  200  11  6   4.7   2.6
  7250   8.5  47.3  215   5  3   8.3   4.5 |   9.7  49.5  195   9  5   3.7   2.1
  7000   9.1  48.4  220   5  2   8.3   4.5 |  10.0  50.0  195   7  4   3.9   2.1
  6750   9.7  49.5  225   4  2   8.9   4.9 |  10.3  50.5  190   5  3   4.4   2.4
  6500  10.5  50.9  230   4  2  10.2   5.6 |  10.6  51.1  190   4  2   5.0   2.7
  6250  11.3  52.3  230   4  2  11.0   6.0 |  11.0  51.8  200   3  1   5.0   2.7
  6000  12.1  53.8  230   4  2  10.2   5.6 |  11.4  52.5  220   2  1   5.8   3.2
  5750  12.8  55.0  235   4  2   9.7   5.3 |  11.8  53.2  275   1  1   2.1   1.2
  5500  13.5  56.3  235   4  2   9.9   5.4 |  11.6  52.9  300   1  1  -3.6  -2.0
  5250  14.3  57.7  240   4  2   9.9   5.4 |  11.4  52.5  300   1  1  -2.2  -1.2
  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.