Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 121307
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0707 MDT Saturday, August 12, 2017

This forecast is for Saturday, August 12, 2017:

If the trigger temperature of 79.8 F/26.5 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 582 ft/min (3.0 m/s)
   Maximum height of thermals.................. 16187 ft MSL (11348 ft AGL)

Forecast maximum temperature................... 90.0 F/32.7 C
Time of trigger temperature.................... 1130 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................. 12078 ft MSL (7239 ft AGL)
Thermal soaring outlook for Sunday 08/13....... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:24:53 / 20:13:44 MDT
Total possible sunshine........... 13 hr 48 min 52 sec (828 min 52 sec)
Altitude of sun at 13:19:00 MDT... 65.60 degrees

Upper air data from rawinsonde observation taken on 08/12/2017 at 0600 MDT

Freezing level.................. 15194 ft MSL (10355 ft AGL)
Convective condensation level... 14168 ft MSL (9329 ft AGL)
Lifted condensation level....... 15104 ft MSL (10264 ft AGL)
Lifted index.................... -3.1
K index......................... +21.0

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  -64.0 -83.2   270   32   17   2.7   1.5   88.0 190.4    32.3      M    M
 45000  -59.2 -74.6   260   53   27   7.7   4.2   70.2 158.4    23.7      M    M
 40000  -51.3 -60.3   265   65   34   8.1   4.4   59.8 139.6    18.4      M    M
 38000  -46.5 -51.7   255   67   34   8.0   4.4   58.4 137.1    17.9      M    M
 36000  -42.6 -44.7   265   60   31   5.5   3.0   55.5 132.0    16.4      M    M
 34000  -38.4 -37.1   265   58   30   6.7   3.7   53.1 127.5    15.0      M    M
 32000  -34.3 -29.7   260   57   29   8.5   4.7   50.9 123.6    13.8      M    M
 30000  -30.8 -23.4   270   45   23   7.4   4.1   46.9 116.4    11.0      M    M
 29000  -28.2 -18.8   270   42   21   5.4   3.0   46.4 115.5    10.8      M    M
 28000  -25.9 -14.6   270   38   20   8.0   4.4   45.6 114.2    10.4      M    M
 27000  -23.3  -9.9   270   35   18   7.9   4.3   45.1 113.2    10.1      M    M
 26000  -21.3  -6.3   270   32   17   2.3   1.3   44.0 111.3     9.4      M    M
 25000  -19.5  -3.1   270   29   15   8.3   4.5   42.7 108.8     8.3      M    M
 24000  -17.8  -0.0   280   25   13   4.9   2.7   41.1 106.0     7.2      M    M
 23000  -15.7   3.7   285   22   11   5.5   3.0   40.2 104.3     6.4      M    M
 22000  -15.0   5.0   295   19   10   3.4   1.9   37.7  99.8     4.2      M    M
 21000  -13.7   7.3   305   16    8   8.3   4.6   35.9  96.6     2.7      M    M
 20000  -11.1  12.0   300   16    8   7.8   4.3   35.5  95.8     2.4      M    M
 19500   -9.9  14.2   305   11    6   9.4   5.2   35.2  95.3     2.2      M    M
 19000   -8.4  16.9   320    8    4   8.2   4.5   35.1  95.2     2.2      M    M
 18500   -7.1  19.2   340    9    5   7.7   4.2   34.9  94.8     2.1      M    M
 18000   -6.2  20.8   355   11    5   6.1   3.4   34.1  93.5     1.5      M    M
 17500   -5.0  23.0   360    9    5   7.8   4.3   33.9  92.9     1.3      M    M
 17000   -3.4  25.9   005    5    3   9.0   4.9   33.3  92.0     0.7      M    M
 16500   -2.4  27.7   015    3    1   6.2   3.4   32.9  91.2     0.3      M    M
 16000   -1.5  29.3   045    1    1   6.8   3.7   32.4  90.3    -0.4    959  4.9
 15500   -0.5  31.1   010    1    1   7.1   3.9   31.9  89.4    -0.8    912  4.6
 15000    0.6  33.1   350    2    1   7.8   4.3   31.5  88.7    -1.1    864  4.4
 14500    1.7  35.1   340    2    1   7.3   4.0   31.2  88.1    -1.5    818  4.2
 14000    2.7  36.9   330    3    2   8.9   4.9   30.9  87.6    -2.0    772  3.9
 13500    4.0  39.2   310    4    2   8.8   4.8   30.7  87.3    -2.2    719  3.7
 13000    5.3  41.5   295    5    2   8.5   4.6   30.5  86.9    -2.4    666  3.4
 12500    6.5  43.7   285    6    3   7.4   4.1   30.2  86.4    -2.6    615  3.1
 12000    7.5  45.5   280    7    4   7.6   4.2   29.9  85.8    -3.1    570  2.9
 11500    8.5  47.3   295    9    5   7.8   4.3   29.5  85.2    -3.6    525  2.7
 11000    9.7  49.5   300   12    6   7.9   4.4   29.2  84.6    -3.9    476  2.4
 10500   10.8  51.4   295   11    6   7.8   4.3   29.0  84.1    -4.2    425  2.2
 10250   11.4  52.5   290   11    6   7.5   4.1   28.8  83.8    -4.3    401  2.0
 10000   12.0  53.6   285   12    6   7.5   4.1   28.6  83.5    -4.5    376  1.9
  9750   12.5  54.5   280   12    6   7.5   4.1   28.4  83.2    -4.7    352  1.8
  9500   13.1  55.6   275   13    6   7.5   4.1   28.2  82.8    -4.9    328  1.7
  9250   13.7  56.7   270   13    7   7.7   4.2   28.1  82.5    -5.0    304  1.5
  9000   14.2  57.6   265   14    7   7.0   3.8   27.9  82.3    -5.2    279  1.4
  8750   14.6  58.3   265   12    6   3.4   1.8   27.6  81.7    -5.5    260  1.3
  8500   14.7  58.5   270   10    5   1.4   0.8   27.0  80.5    -6.2    249  1.3
  8250   14.8  58.6   275    8    4   1.9   1.1   26.3  79.4    -6.8    239  1.2
  8000   14.9  58.8   285    6    3   1.8   1.0   25.7  78.3    -7.5    228  1.2
  7750   15.1  59.2   270    4    2   1.8   1.0   25.1  77.2    -8.1    218  1.1
  7500   15.2  59.4   220    3    1   1.9   1.0   24.5  76.1    -8.8    207  1.1
  7250   15.3  59.5   175    4    2   1.6   0.9   23.9  75.0    -9.4    197  1.0
  7000   15.4  59.7   155    6    3   2.8   1.6   23.3  73.9   -10.0    186  0.9
  6750   15.6  60.1   150    7    3   5.0   2.7   22.9  73.2   -10.5    171  0.9
  6500   16.0  60.8   145    6    3   5.2   2.9   22.5  72.5   -10.9    153  0.8
  6250   16.3  61.3   140    6    3   5.2   2.9   22.2  71.9   -11.3    135  0.7
  6000   16.7  62.1   130    5    3   5.1   2.8   21.8  71.3   -11.7    117  0.6
  5750   17.0  62.6   135    5    3   5.7   3.2   21.5  70.7   -12.1     99  0.5
  5500   17.4  63.3   145    5    2   3.3   1.8   21.2  70.1   -12.5     81  0.4
  5250   17.3  63.1   155    5    2  -4.4  -2.4   20.4  68.7   -13.4     77  0.4
  5000   16.6  61.9   165    5    3 -12.2  -6.7   19.0  66.2   -14.9     92  0.5

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

           08/12/2017 at 0900 MDT          |       08/12/2017 at 1200 MDT
                                           |
K index... +24.7  LI... -3.3               | K index... +25.8  LI... -4.5
CAPE... +564.0  CIN... -27.4               | CAPE... +795.0  CIN... -33.7
                                           |
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 -63.3 -81.9  270  40 21   2.1   1.2 | -63.4 -82.1  275  42 21   2.0   1.1
 45000 -58.8 -73.8  270  57 29   5.0   2.7 | -59.0 -74.2  270  60 31   5.3   2.9
 40000 -50.6 -59.1  270  64 33   6.7   3.7 | -50.5 -58.9  270  65 33   6.1   3.4
 38000 -46.6 -51.9  270  62 32   6.7   3.7 | -46.8 -52.2  270  63 32   6.1   3.4
 36000 -42.6 -44.7  270  60 31   6.7   3.7 | -43.1 -45.6  270  61 31   6.0   3.3
 34000 -38.2 -36.8  270  56 29   7.3   4.0 | -38.9 -38.0  275  56 29   7.2   3.9
 32000 -33.8 -28.8  275  52 27   7.4   4.1 | -34.6 -30.3  275  50 26   7.2   3.9
 30000 -30.3 -22.5  280  43 22   5.6   3.1 | -30.4 -22.7  280  43 22   6.9   3.8
 29000 -28.6 -19.5  280  38 19   5.6   3.1 | -27.9 -18.2  285  38 20   6.9   3.8
 28000 -27.0 -16.6  280  33 17   6.3   3.5 | -25.8 -14.4  285  35 18   6.4   3.5
 27000 -24.9 -12.8  285  29 15   7.0   3.9 | -23.9 -11.0  285  31 16   6.4   3.5
 26000 -22.8  -9.0  290  26 13   7.1   3.9 | -22.0  -7.6  280  27 14   6.4   3.5
 25000 -20.7  -5.3  295  22 11   7.1   3.9 | -20.1  -4.2  280  23 12   6.4   3.5
 24000 -18.6  -1.5  295  20 10   6.7   3.7 | -18.2  -0.8  280  20 10   6.4   3.5
 23000 -16.6   2.1  290  19 10   6.7   3.7 | -16.4   2.5  280  18  9   6.5   3.6
 22000 -14.1   6.6  285  18  9   7.0   3.9 | -14.5   5.9  280  16  8   6.7   3.7
 21000 -12.0  10.4  290  16  8   7.2   4.0 | -12.4   9.7  280  15  8   6.9   3.8
 20000  -9.8  14.4  290  15  7   7.2   4.0 | -10.4  13.3  280  15  8   6.9   3.8
 19500  -8.7  16.3  290  14  7   7.1   3.9 |  -9.4  15.1  280  15  8   6.8   3.7
 19000  -7.7  18.1  290  11  6   6.7   3.7 |  -8.3  17.1  280  14  7   7.9   4.3
 18500  -6.7  19.9  295   8  4   6.8   3.7 |  -7.1  19.2  280  12  6   7.8   4.3
 18000  -5.7  21.7  295   6  3   7.4   4.0 |  -6.0  21.2  285  11  6   7.6   4.2
 17500  -4.6  23.7  295   5  2   7.5   4.1 |  -4.9  23.2  285  10  5   7.4   4.1
 17000  -3.4  25.9  295   4  2   7.5   4.1 |  -3.8  25.2  285   9  5   7.5   4.1
 16500  -2.4  27.7  295   3  2   7.4   4.1 |  -2.7  27.1  290   8  4   7.5   4.1
 16000  -1.3  29.7  295   3  2   7.4   4.1 |  -1.7  28.9  290   8  4   7.5   4.1
 15500  -0.2  31.6  295   3  2   7.9   4.3 |  -0.6  30.9  295   8  4   8.1   4.4
 15000   0.9  33.6  290   3  2   7.9   4.3 |   0.6  33.1  300   8  4   8.2   4.5
 14500   2.1  35.8  285   4  2   7.8   4.3 |   1.8  35.2  300   8  4   7.9   4.4
 14000   3.2  37.8  280   4  2   7.7   4.2 |   3.5  38.3  305   8  4   7.5   4.1
 13500   4.3  39.7  275   5  2   7.4   4.0 |   4.6  40.3  305   8  4   8.0   4.4
 13000   5.2  41.4  275   5  3   7.0   3.8 |   5.7  42.3  310   8  4   8.2   4.5
 12500   6.1  43.0  275   6  3   7.0   3.8 |   6.8  44.2  310   7  4   8.0   4.4
 12000   7.0  44.6  280   7  4   6.8   3.7 |   8.0  46.4  310   7  4   7.9   4.3
 11500   7.8  46.0  285   8  4   6.8   3.8 |   9.1  48.4  305   7  3   7.0   3.9
 11000   8.7  47.7  285   8  4   6.6   3.6 |   9.9  49.8  305   6  3   6.2   3.4
 10500   9.6  49.3  285   8  4   4.9   2.7 |  10.8  51.4  300   6  3   3.5   1.9
 10250   9.8  49.6  285   8  4   3.9   2.1 |  10.9  51.6  300   6  3   4.7   2.6
 10000  10.2  50.4  285   8  4   6.9   3.8 |  11.5  52.7  295   6  3   9.0   5.0
  9750  10.8  51.4  285   7  4   8.0   4.4 |  12.0  53.6  295   6  3   8.3   4.5
  9500  11.3  52.3  285   7  4   6.7   3.7 |  12.5  54.5  295   5  3   6.6   3.6
  9250  11.7  53.1  285   6  3   4.2   2.3 |  12.9  55.2  290   5  3   5.8   3.2
  9000  12.0  53.6  285   6  3   5.2   2.9 |  13.4  56.1  290   4  2   7.9   4.4
  8750  12.5  54.5  280   4  2   7.0   3.8 |  13.9  57.0  285   4  2   8.0   4.4
  8500  13.0  55.4  280   3  2   6.0   3.3 |  14.4  57.9  275   3  2   6.5   3.5
  8250  13.4  56.1  275   2  1   5.1   2.8 |  14.8  58.6  270   3  1   5.4   3.0
  8000  13.8  56.8  260   2  1   5.7   3.1 |  15.2  59.4  255   2  1   6.7   3.7
  7750  14.3  57.7  235   2  1   6.8   3.7 |  15.8  60.4  245   2  1   8.6   4.7
  7500  14.8  58.6  210   2  1   6.3   3.5 |  16.4  61.5  240   2  1  10.2   5.6
  7250  15.2  59.4  195   3  1   5.6   3.1 |  17.2  63.0  240   2  1  11.0   6.0
  7000  15.6  60.1  190   4  2   5.8   3.2 |  18.0  64.4  240   2  1  10.1   5.6
  6750  16.0  60.8  185   5  2   5.8   3.2 |  18.7  65.7  240   2  1  10.3   5.7
  6500  16.4  61.5  180   5  2   5.5   3.0 |  19.6  67.3  240   2  1  11.0   6.0
  6250  16.9  62.4  170   4  2   6.3   3.5 |  20.4  68.7  235   2  1  11.3   6.2
  6000  17.3  63.1  160   4  2   3.1   1.7 |  21.2  70.2  235   2  1   9.8   5.4
  5750  17.5  63.5  150   4  2   7.9   4.3 |  21.9  71.4  240   2  1  12.5   6.8
  5500  18.7  65.7  145   4  2  25.2  13.9 |  23.1  73.6  240   2  1  16.7   9.1
  5250     M     M    M   M  M     M     M |  24.2  75.6  245   2  1  13.4   7.3
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           08/12/2017 at 1500 MDT          |       08/12/2017 at 1800 MDT
                                           |
K index... +22.8  LI... -3.8               | K index... +21.0  LI... -2.2
CAPE... +763.6  CIN... -33.4               | CAPE... +395.2  CIN... -31.4
                                           |
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 -63.3 -81.9  275  43 22   2.2   1.2 | -63.8 -82.8  280  45 23   2.4   1.3
 45000 -58.1 -72.6  275  63 33   5.6   3.1 | -58.8 -73.8  280  64 33   5.6   3.1
 40000 -49.8 -57.6  270  70 36   5.2   2.9 | -50.1 -58.2  280  72 37   4.9   2.7
 38000 -46.7 -52.1  270  69 35   5.2   2.9 | -47.1 -52.8  280  70 36   4.9   2.7
 36000 -43.6 -46.5  270  67 34   4.9   2.7 | -44.2 -47.6  280  67 34   4.7   2.6
 34000 -39.4 -38.9  275  60 31   7.2   4.0 | -39.9 -39.8  285  58 30   7.4   4.1
 32000 -35.0 -31.0  280  52 27   7.2   3.9 | -35.5 -31.9  290  50 26   7.2   4.0
 30000 -30.1 -22.2  280  43 22   7.4   4.1 | -30.8 -23.4  295  43 22   8.0   4.4
 29000 -27.8 -18.0  280  39 20   7.4   4.1 | -27.8 -18.0  295  39 20   8.0   4.4
 28000 -25.7 -14.3  285  35 18   6.4   3.5 | -25.4 -13.7  290  36 18   7.5   4.1
 27000 -23.8 -10.8  280  32 16   6.3   3.5 | -23.2  -9.8  290  33 17   7.5   4.1
 26000 -21.9  -7.4  280  28 15   6.4   3.5 | -20.9  -5.6  285  31 16   7.5   4.1
 25000 -20.0  -4.0  280  25 13   6.7   3.7 | -18.7  -1.7  280  28 15   7.1   3.9
 24000 -17.8  -0.0  280  23 12   7.6   4.1 | -16.8   1.8  280  26 14   6.4   3.5
 23000 -15.5   4.1  275  22 11   7.6   4.2 | -14.8   5.4  275  24 13   6.4   3.5
 22000 -13.3   8.1  275  21 11   7.2   3.9 | -12.9   8.8  270  23 12   6.6   3.6
 21000 -11.3  11.7  275  18  9   6.6   3.6 | -11.0  12.2  265  21 11   6.8   3.7
 20000  -9.4  15.1  275  16  8   6.6   3.6 |  -9.0  15.8  265  20 10   6.9   3.8
 19500  -8.4  16.9  275  15  8   6.6   3.6 |  -8.0  17.6  265  20 10   6.9   3.8
 19000  -7.4  18.7  280  14  7   6.9   3.8 |  -6.9  19.6  265  19 10   7.3   4.0
 18500  -6.4  20.5  280  14  7   6.9   3.8 |  -5.8  21.6  265  18  9   7.3   4.0
 18000  -5.4  22.3  285  13  7   7.1   3.9 |  -4.7  23.5  265  17  9   7.2   3.9
 17500  -4.3  24.3  285  12  6   7.4   4.1 |  -3.7  25.3  265  16  8   7.0   3.9
 17000  -3.2  26.2  290  12  6   7.4   4.1 |  -2.7  27.1  265  15  8   6.9   3.8
 16500  -2.1  28.2  290  11  6   8.2   4.5 |  -1.6  29.1  265  15  8   8.4   4.6
 16000  -0.9  30.4  290  11  5   8.1   4.5 |  -0.4  31.3  265  14  7   8.2   4.5
 15500   0.2  32.4  290  10  5   8.4   4.6 |   0.8  33.4  260  14  7   8.1   4.4
 15000   1.4  34.5  290  10  5   8.5   4.6 |   2.0  35.6  260  13  7   8.0   4.4
 14500   2.6  36.7  290  10  5   8.5   4.6 |   3.1  37.6  260  13  7   8.1   4.4
 14000   4.4  39.9  290  10  5   8.4   4.6 |   4.8  40.6  260  12  6   8.2   4.5
 13500   5.6  42.1  290   9  5   8.0   4.4 |   6.0  42.8  260  11  6   8.4   4.6
 13000   6.8  44.2  290   9  4   7.9   4.3 |   7.2  45.0  260  11  6   8.5   4.7
 12500   7.9  46.2  290   8  4   8.2   4.5 |   8.4  47.1  265  11  6   8.7   4.8
 12000   9.1  48.4  290   7  4   8.4   4.6 |   9.7  49.5  265  10  5   8.9   4.9
 11500  10.3  50.5  290   6  3   8.4   4.6 |  11.0  51.8  265  10  5   8.7   4.8
 11000  11.5  52.7  290   5  3   8.2   4.5 |  12.2  54.0  265  10  5   8.3   4.5
 10500  12.7  54.9  285   4  2   5.3   2.9 |  13.4  56.1  265   9  5   6.3   3.4
 10250  13.0  55.4  280   4  2   6.2   3.4 |  13.8  56.8  265   9  4   7.2   4.0
 10000  13.7  56.7  275   3  2  10.6   5.8 |  14.6  58.3  265   8  4  10.5   5.8
  9750  14.4  57.9  270   3  2  10.1   5.5 |  15.3  59.5  265   8  4  10.1   5.5
  9500  15.2  59.4  265   3  1   7.6   4.2 |  16.0  60.8  265   7  4   8.5   4.7
  9250  15.6  60.1  260   2  1   6.0   3.3 |  16.5  61.7  265   7  3   7.3   4.0
  9000  16.1  61.0  255   2  1   8.0   4.4 |  17.1  62.8  265   6  3   8.5   4.6
  8750  16.7  62.1  250   2  1   7.8   4.3 |  17.7  63.9  265   6  3   8.4   4.6
  8500  17.2  63.0  245   2  1   8.0   4.4 |  18.3  64.9  265   5  3   8.2   4.5
  8250  17.7  63.9  245   2  1   8.3   4.6 |  18.8  65.8  265   5  3   8.1   4.4
  8000  18.2  64.8  240   2  1   9.3   5.1 |  19.4  66.9  265   5  2   8.9   4.9
  7750  18.9  66.0  240   2  1  10.0   5.5 |  20.1  68.2  265   5  2   9.4   5.1
  7500  19.6  67.3  240   2  1   9.9   5.5 |  20.7  69.3  265   5  2   9.6   5.3
  7250  20.3  68.5  240   2  1  10.1   5.6 |  21.5  70.7  265   5  2   9.8   5.4
  7000  21.1  70.0  240   2  1   9.7   5.3 |  22.2  72.0  265   5  2   9.8   5.4
  6750  21.8  71.2  240   2  1  10.2   5.6 |  22.9  73.2  265   5  2  10.2   5.6
  6500  22.6  72.7  240   2  1  11.3   6.2 |  23.7  74.7  265   5  2  10.6   5.8
  6250  23.5  74.3  240   2  1  12.1   6.6 |  24.5  76.1  265   5  2  11.2   6.1
  6000  24.3  75.7  240   2  1   9.8   5.4 |  25.3  77.5  265   5  2   9.7   5.3
  5750  25.1  77.2  240   2  1  12.3   6.7 |  26.0  78.8  265   4  2   9.6   5.3
  5500  26.2  79.2  240   2  1  17.3   9.5 |  26.8  80.2  265   4  2  11.4   6.3
  5250  27.4  81.3  245   2  1  13.3   7.3 |  27.6  81.7  270   4  2  10.3   5.6
  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



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