Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 201245
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0545 MST Monday, November 20, 2017

This forecast is for Monday, November 20, 2017:

If the trigger temperature of 54.6 F/12.6 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 7740 ft MSL (2901 ft AGL)

Forecast maximum temperature................... 51.0 F/11.0 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 7372 ft MSL (2532 ft AGL)
Thermal soaring outlook for Tuesday 11/21...... Fair

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

Remarks...

Sunrise/Sunset.................... 07:03:14 / 16:56:25 MST
Total possible sunshine........... 9 hr 53 min 10 sec (593 min 10 sec)
Altitude of sun at 12:00:00 MST... 31.07 degrees

Upper air data from rawinsonde observation taken on 11/20/2017 at 0500 MST

Freezing level.................. 5402 ft MSL (563 ft AGL)
Additional freezing levels...... 6541 ft MSL (1702 ft AGL)
                                 7425 ft MSL (2586 ft AGL)
Convective condensation level... 21386 ft MSL (16547 ft AGL)
Lifted condensation level....... 14261 ft MSL (9422 ft AGL)
Lifted index.................... +14.9
K index......................... -30.5

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  -67.2 -89.0   305   64   33  -7.8  -4.3   90.2 194.3    45.1      M    M
 45000  -65.7 -86.3   315   73   38  -3.1  -1.7   67.9 154.2    34.9      M    M
 40000  -61.4 -78.5   320  143   74   7.6   4.1   50.1 122.2    25.9      M    M
 38000  -56.7 -70.1   320  127   65   7.8   4.3   48.1 118.5    25.3      M    M
 36000  -52.0 -61.6   315  108   55   5.9   3.2   46.6 115.9    24.9      M    M
 34000  -49.4 -56.9   310   96   49   7.9   4.4   41.8 107.2    22.2      M    M
 32000  -44.7 -48.5   305   93   48   8.0   4.4   40.2 104.3    21.6      M    M
 30000  -39.2 -38.6   305   87   45   6.4   3.5   39.0 102.2    21.3      M    M
 29000  -37.4 -35.3   305   79   41   6.1   3.4   37.5  99.5    20.4      M    M
 28000  -35.4 -31.7   305   71   37   8.1   4.5   36.3  97.4    19.7      M    M
 27000  -33.0 -27.4   305   63   33   8.0   4.4   35.6  96.0    19.4      M    M
 26000  -30.7 -23.3   300   56   29   8.0   4.4   34.9  94.9    19.1      M    M
 25000  -28.3 -18.9   300   48   25   8.0   4.4   34.4  93.9    18.9      M    M
 24000  -25.9 -14.6   300   47   24   7.6   4.2   33.7  92.6    18.5      M    M
 23000  -23.7 -10.7   295   45   23   7.6   4.2   32.8  91.1    18.0      M    M
 22000  -21.7  -7.1   290   43   22   4.7   2.6   31.8  89.2    17.3      M    M
 21000  -20.4  -4.7   285   42   22   3.2   1.8   29.9  85.8    15.9      M    M
 20000  -19.4  -2.9   280   41   21   3.4   1.9   27.6  81.7    14.2      M    M
 19500  -18.8  -1.8   280   38   20   6.5   3.5   26.5  79.7    13.4      M    M
 19000  -17.5   0.5   280   34   18   8.2   4.5   26.3  79.4    13.3      M    M
 18500  -16.2   2.8   280   32   17   9.5   5.2   26.1  79.0    13.2      M    M
 18000  -14.7   5.5   280   33   17   9.6   5.3   26.1  78.9    13.2      M    M
 17500  -13.3   8.1   280   34   18   9.6   5.3   26.1  78.9    13.3      M    M
 17000  -11.8  10.8   285   35   18   9.6   5.3   26.1  78.9    13.4      M    M
 16500   -9.9  14.2   285   36   19   5.5   3.0   25.7  78.3    13.3      M    M
 16000   -9.3  15.3   285   36   19   5.5   3.0   24.7  76.5    12.5      M    M
 15500   -8.4  16.9   285   34   17   5.7   3.1   24.0  75.2    12.0      M    M
 15000   -7.6  18.3   285   32   16   6.6   3.6   23.4  74.0    11.4      M    M
 14500   -7.2  19.0   280   29   15  -1.2  -0.7   22.2  71.9    10.4      M    M
 14000   -6.5  20.3   280   27   14   9.1   5.0   21.4  70.5     9.8      M    M
 13500   -5.2  22.6   280   27   14   8.5   4.7   21.2  70.1     9.6      M    M
 13000   -3.9  25.0   285   26   14   8.4   4.6   21.0  69.7     9.5      M    M
 12500   -2.6  27.3   285   26   13   7.4   4.1   20.8  69.4     9.4      M    M
 12000   -1.7  28.9   285   26   13   5.8   3.2   20.2  68.3     8.9      M    M
 11500   -0.8  30.6   275   25   13   5.8   3.2   19.5  67.1     8.3      M    M
 11000    0.0  32.0   270   25   13   5.9   3.2   18.9  66.0     7.7      M    M
 10500    0.9  33.6   260   25   13   6.6   3.6   18.3  64.9     7.2      M    M
 10250    1.3  34.3   255   26   13   3.2   1.7   18.0  64.4     6.9      M    M
 10000    1.1  34.0   255   26   13  -8.3  -4.5   17.0  62.7     6.1      M    M
  9750    0.4  32.7   250   22   12  -6.7  -3.7   15.5  59.9     4.6      M    M
  9500    0.2  32.4   245   19   10   1.1   0.6   14.6  58.3     3.7      M    M
  9250    0.3  32.5   235   16    8   1.1   0.6   13.9  57.0     3.1      M    M
  9000    0.3  32.5   220   14    7   0.2   0.1   13.2  55.8     2.4      M    M
  8750    0.4  32.7   215   12    6   4.0   2.2   12.5  54.6     1.7      M    M
  8500    0.9  33.6   210   11    6   7.9   4.4   12.3  54.2     1.5      M    M
  8250    1.5  34.7   205    9    5   7.1   3.9   12.1  53.8     1.3      M    M
  8000    2.0  35.6   195    8    4   7.2   3.9   11.9  53.5     1.1      M    M
  7750    2.0  35.6   185    9    4 -11.8  -6.5   11.2  52.2     0.4      M    M
  7500    0.4  32.7   175   10    5 -19.3 -10.6    8.9  48.0    -1.9    226  1.1
  7250   -0.4  31.3   165   11    6  -5.1  -2.8    7.3  45.2    -3.5    244  1.2
  7000   -0.6  30.9   160   13    7   1.6   0.9    6.4  43.6    -4.4    240  1.2
  6750   -0.3  31.5   155   11    6   4.3   2.4    6.0  42.7    -4.8    224  1.1
  6500   -0.0  32.0   150   10    5   3.5   1.9    5.5  41.9    -5.3    209  1.1
  6250    0.3  32.5   140    8    4   4.0   2.2    5.0  41.1    -5.8    193  1.0
  6000    0.5  32.9   130    6    3   2.8   1.5    4.6  40.3    -6.2    177  0.9
  5750    0.8  33.4   125    6    3   7.0   3.8    4.1  39.4    -6.7    162  0.8
  5500    1.1  34.0   125    5    3  -8.6  -4.7    3.7  38.6    -7.2    146  0.7
  5250   -0.4  31.3   130    5    2 -22.0 -12.1    1.4  34.6    -9.4    185  0.9
  5000   -1.3  29.7   130    4    2   2.4   1.3   -0.2  31.7   -11.1    203  1.0

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

           11/20/2017 at 0800 MST          |       11/20/2017 at 1100 MST
                                           |
K index... -14.2  LI... +7.3               | K index... -18.9  LI... +7.8
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 -66.3 -87.3  315  70 36  -1.7  -0.9 | -65.6 -86.1  310  69 35  -1.0  -0.5
 45000 -68.6 -91.5  315  93 48   3.0   1.7 | -66.5 -87.7  305  94 48   4.6   2.5
 40000 -60.8 -77.4  320 140 72   5.1   2.8 | -60.2 -76.4  320 122 63   4.3   2.4
 38000 -56.4 -69.5  320 135 70   8.0   4.4 | -56.2 -69.2  320 120 62   7.5   4.1
 36000 -51.6 -60.9  315 123 63   8.0   4.4 | -51.7 -61.1  315 113 58   7.5   4.1
 34000 -47.1 -52.8  315 110 57   7.0   3.9 | -47.1 -52.8  310 107 55   7.7   4.2
 32000 -42.8 -45.0  310  99 51   7.0   3.9 | -41.9 -43.4  310 100 51   7.7   4.2
 30000 -38.6 -37.5  310  88 45   7.1   3.9 | -37.2 -35.0  305  93 48   7.6   4.2
 29000 -36.0 -32.8  310  81 42   7.1   3.9 | -35.0 -31.0  305  88 45   7.6   4.2
 28000 -33.9 -29.0  305  76 39   7.1   3.9 | -32.7 -26.9  305  83 43   7.6   4.2
 27000 -31.7 -25.1  305  71 36   7.3   4.0 | -30.5 -22.9  305  78 40   6.3   3.5
 26000 -29.6 -21.3  305  66 34   7.3   4.0 | -28.6 -19.5  305  71 36   6.4   3.5
 25000 -27.4 -17.3  300  61 32   7.4   4.0 | -26.7 -16.1  305  64 33   6.4   3.5
 24000 -25.2 -13.4  300  57 29   6.7   3.7 | -24.8 -12.6  305  57 29   6.4   3.5
 23000 -23.2  -9.8  300  52 27   6.7   3.7 | -22.9  -9.2  300  53 27   6.4   3.5
 22000 -21.3  -6.3  300  47 24   6.7   3.7 | -21.0  -5.8  300  49 25   6.4   3.5
 21000 -19.3  -2.7  295  43 22   6.5   3.5 | -19.1  -2.4  300  45 23   6.6   3.6
 20000 -17.4   0.7  295  41 21   6.5   3.6 | -17.2   1.0  300  44 23   6.6   3.6
 19500 -16.4   2.5  295  40 21   6.5   3.6 | -16.2   2.8  295  43 22   6.6   3.6
 19000 -15.5   4.1  295  40 20   6.7   3.7 | -15.3   4.5  295  43 22   6.8   3.7
 18500 -14.6   5.7  290  39 20   4.1   2.2 | -14.4   6.1  295  42 22   4.3   2.4
 18000 -14.1   6.6  290  38 20   4.0   2.2 | -13.8   7.2  295  42 22   4.1   2.2
 17500 -13.5   7.7  290  37 19   5.1   2.8 | -13.1   8.4  290  42 22   4.3   2.4
 17000 -12.4   9.7  290  36 19   7.3   4.0 | -12.3   9.9  290  41 21   5.1   2.8
 16500 -11.3  11.7  290  35 18   7.4   4.1 | -11.5  11.3  285  40 20   4.9   2.7
 16000 -10.2  13.6  290  34 18   6.3   3.5 | -10.5  13.1  285  38 20   7.7   4.2
 15500  -9.2  15.4  290  33 17   6.5   3.6 |  -9.4  15.1  285  36 18   7.5   4.1
 15000  -8.2  17.2  290  32 17   6.8   3.7 |  -7.7  18.1  280  32 16   6.7   3.7
 14500  -7.1  19.2  290  31 16   6.9   3.8 |  -6.7  19.9  280  29 15   6.7   3.7
 14000  -5.5  22.1  290  29 15   7.3   4.0 |  -5.7  21.7  280  27 14   7.4   4.1
 13500  -4.4  24.1  290  27 14   7.3   4.0 |  -4.6  23.7  280  25 13   7.4   4.1
 13000  -3.4  25.9  290  25 13   6.9   3.8 |  -3.5  25.7  285  23 12   6.7   3.7
 12500  -2.3  27.9  285  24 12   7.0   3.8 |  -2.5  27.5  280  22 11   6.8   3.7
 12000  -1.4  29.5  285  23 12   5.6   3.1 |  -1.5  29.3  280  21 11   5.4   3.0
 11500  -0.6  30.9  280  22 11   5.6   3.1 |  -0.8  30.6  280  21 11   5.4   3.0
 11000   0.1  32.2  275  21 11   3.2   1.8 |  -0.1  31.8  275  20 10   3.0   1.6
 10500   0.5  32.9  270  19 10   3.3   1.8 |   0.3  32.5  270  19 10   2.9   1.6
 10250   0.7  33.3  265  19 10   1.6   0.9 |   0.5  32.9  265  18  9   1.7   0.9
 10000   0.8  33.4  265  18  9   1.8   1.0 |   0.6  33.1  265  18  9   2.4   1.3
  9750   1.0  33.8  260  17  9   3.5   1.9 |   0.9  33.6  260  17  9   4.1   2.2
  9500   1.2  34.2  255  16  8   3.3   1.8 |   1.1  34.0  255  16  8   3.7   2.0
  9250   1.5  34.7  250  15  8   2.3   1.3 |   1.4  34.5  255  15  8   3.6   2.0
  9000   1.5  34.7  250  14  7   0.2   0.1 |   1.6  34.9  250  15  7   1.8   1.0
  8750   1.5  34.7  245  13  6  -0.4  -0.2 |   1.7  35.1  250  13  7   0.2   0.1
  8500   1.5  34.7  240  11  6  -0.3  -0.2 |   1.7  35.1  245  12  6   0.3   0.2
  8250   1.5  34.7  230  10  5   1.2   0.7 |   1.7  35.1  245  11  5   1.0   0.6
  8000   1.6  34.9  220   9  4   2.4   1.3 |   1.8  35.2  240   9  5   1.7   1.0
  7750   1.8  35.2  210   8  4   2.8   1.5 |   1.9  35.4  235   8  4   2.0   1.1
  7500   2.1  35.8  200   8  4   3.3   1.8 |   2.1  35.8  230   7  4   3.0   1.6
  7250   2.3  36.1  195   9  5   3.3   1.8 |   2.4  36.3  225   6  3   3.7   2.1
  7000   2.6  36.7  190  10  5   3.4   1.9 |   2.6  36.7  220   6  3   3.8   2.1
  6750   2.8  37.0  185  11  5   1.4   0.8 |   2.9  37.2  220   5  3   5.4   3.0
  6500   2.7  36.9  180  10  5  -2.4  -1.3 |   3.4  38.1  220   4  2   7.8   4.3
  6250   2.4  36.3  175   9  5  -5.9  -3.2 |   4.1  39.4  225   4  2   8.7   4.8
  6000   2.1  35.8  165   8  4   1.2   0.7 |   4.7  40.5  230   4  2   8.0   4.4
  5750   2.3  36.1  140   6  3  -3.2  -1.8 |   5.3  41.5  235   3  2   9.3   5.1
  5500   1.4  34.5  130   5  2 -15.4  -8.5 |   6.1  43.0  240   3  2  11.0   6.0
  5250   0.5  32.9  110   4  2  -5.6  -3.1 |   6.8  44.2  240   3  2   9.7   5.3
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           11/20/2017 at 1400 MST          |       11/20/2017 at 1700 MST
                                           |
K index... +0.5  LI... +7.4                | K index... +3.4  LI... +6.6
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 -65.3 -85.5  305  71 37  -1.2  -0.7 | -64.9 -84.8  305  75 39  -1.0  -0.6
 45000 -66.8 -88.2  305 103 53   4.1   2.3 | -66.1 -87.0  310 108 56   3.7   2.0
 40000 -61.3 -78.3  320 135 70   3.2   1.8 | -61.1 -78.0  320 138 71   2.9   1.6
 38000 -56.8 -70.2  320 130 67   8.4   4.6 | -56.5 -69.7  320 142 73   8.8   4.8
 36000 -51.8 -61.2  320 122 63   8.4   4.6 | -51.2 -60.2  320 144 74   8.8   4.8
 34000 -46.9 -52.4  315 111 57   8.1   4.4 | -46.4 -51.5  320 136 70   7.2   4.0
 32000 -42.0 -43.6  305  99 51   8.1   4.4 | -42.1 -43.8  315 117 60   7.2   4.0
 30000 -37.2 -35.0  300  92 47   8.1   4.5 | -37.6 -35.7  310 105 54   7.7   4.2
 29000 -34.7 -30.5  300  91 47   8.2   4.5 | -35.3 -31.5  310 103 53   7.7   4.2
 28000 -32.3 -26.1  300  90 47   8.2   4.5 | -33.0 -27.4  310 101 52   7.7   4.2
 27000 -30.1 -22.2  300  88 45   5.3   2.9 | -30.4 -22.7  310  93 48   6.1   3.3
 26000 -28.1 -18.6  300  76 39   5.2   2.9 | -28.6 -19.5  310  81 42   6.1   3.3
 25000 -26.6 -15.9  305  67 34   5.3   2.9 | -26.8 -16.2  305  69 35   6.1   3.3
 24000 -25.0 -13.0  305  58 30   5.7   3.1 | -25.0 -13.0  305  58 30   5.7   3.1
 23000 -23.3  -9.9  305  52 27   5.6   3.1 | -23.3  -9.9  305  51 26   5.7   3.1
 22000 -21.6  -6.9  305  45 23   5.6   3.1 | -21.6  -6.9  305  45 23   5.8   3.2
 21000 -19.8  -3.6  305  40 21   7.7   4.2 | -19.8  -3.6  305  41 21   7.6   4.1
 20000 -17.5   0.5  305  40 20   7.6   4.2 | -17.5   0.5  300  40 21   7.5   4.1
 19500 -16.4   2.5  300  39 20   7.7   4.2 | -16.4   2.5  300  40 21   7.5   4.1
 19000 -15.3   4.5  300  39 20   7.8   4.3 | -15.3   4.5  300  40 20   7.5   4.1
 18500 -14.2   6.4  300  38 20   6.7   3.6 | -14.2   6.4  300  39 20   7.6   4.2
 18000 -13.3   8.1  300  38 19   6.7   3.7 | -13.1   8.4  300  39 20   7.6   4.2
 17500 -12.3   9.9  300  37 19   6.6   3.6 | -12.0  10.4  300  38 19   7.3   4.0
 17000 -11.4  11.5  300  37 19   6.4   3.5 | -10.9  12.4  300  38 19   7.1   3.9
 16500 -10.5  13.1  300  37 19   6.5   3.6 |  -9.9  14.2  300  38 19   7.1   3.9
 16000  -9.7  14.5  300  37 19   3.7   2.0 |  -9.0  15.8  300  37 19   5.6   3.1
 15500  -9.1  15.6  295  37 19   3.9   2.2 |  -8.2  17.2  300  37 19   5.9   3.2
 15000  -8.5  16.7  295  36 19   4.5   2.5 |  -7.4  18.7  300  37 19   4.4   2.4
 14500  -7.8  18.0  295  36 18   4.6   2.5 |  -6.8  19.8  300  37 19   4.2   2.3
 14000  -7.1  19.2  290  35 18   6.0   3.3 |  -6.2  20.8  295  36 19   4.3   2.4
 13500  -5.9  21.4  290  33 17   7.1   3.9 |  -5.6  21.9  300  35 18   4.5   2.5
 13000  -4.1  24.6  285  30 16   8.6   4.7 |  -4.4  24.1  300  34 18   6.5   3.5
 12500  -2.8  27.0  285  28 15   8.8   4.8 |  -3.4  25.9  300  33 17   6.4   3.5
 12000  -1.6  29.1  280  26 13   6.8   3.7 |  -2.4  27.7  295  31 16   7.0   3.8
 11500  -0.5  31.1  280  25 13   7.0   3.8 |  -1.2  29.8  295  30 15   7.2   4.0
 11000   0.3  32.5  275  23 12   3.5   1.9 |  -0.2  31.6  295  28 15   5.7   3.1
 10500   0.8  33.4  270  22 11   3.5   1.9 |   0.7  33.3  290  26 13   6.0   3.3
 10250   1.0  33.8  265  21 11   2.6   1.4 |   1.1  34.0  290  25 13   4.0   2.2
 10000   1.2  34.2  265  20 10   2.9   1.6 |   1.3  34.3  285  24 12   2.5   1.4
  9750   1.5  34.7  260  20 10   4.0   2.2 |   1.6  34.9  285  22 11   3.5   1.9
  9500   1.7  35.1  260  19 10   3.6   2.0 |   1.8  35.2  280  21 11   3.0   1.7
  9250   2.0  35.6  255  18  9   4.0   2.2 |   2.1  35.8  275  19 10   4.4   2.4
  9000   2.3  36.1  255  18  9   3.3   1.8 |   2.5  36.5  270  18  9   6.0   3.3
  8750   2.5  36.5  250  17  9   2.6   1.4 |   3.0  37.4  265  18  9   6.1   3.4
  8500   2.7  36.9  245  16  8   2.5   1.4 |   3.4  38.1  260  17  9   5.8   3.2
  8250   2.8  37.0  245  14  7   0.8   0.4 |   3.8  38.8  255  16  8   4.3   2.4
  8000   2.8  37.0  245  12  6   0.4   0.2 |   4.0  39.2  255  14  7   2.9   1.6
  7750   2.8  37.0  245  10  5   0.8   0.4 |   4.2  39.6  250  13  7   2.3   1.2
  7500   2.9  37.2  245   8  4   2.6   1.5 |   4.3  39.7  240  11  5   1.1   0.6
  7250   3.2  37.8  250   6  3   4.7   2.6 |   4.3  39.7  240   8  4   0.1   0.1
  7000   3.6  38.5  260   5  3   5.1   2.8 |   4.3  39.7  235   6  3   0.3   0.2
  6750   4.0  39.2  270   5  3   7.6   4.2 |   4.4  39.9  235   4  2   1.9   1.1
  6500   4.7  40.5  270   5  3  10.1   5.5 |   4.6  40.3  235   2  1   4.5   2.5
  6250   5.5  41.9  275   5  3  10.7   5.9 |   5.0  41.0  255   2  1   5.1   2.8
  6000   6.3  43.3  275   5  3  10.1   5.5 |   5.4  41.7  280   2  1   6.0   3.3
  5750   7.0  44.6  275   5  3   9.6   5.3 |   5.8  42.4  310   2  1   2.5   1.4
  5500   7.7  45.9  275   5  3   9.8   5.4 |   5.7  42.3  310   2  1  -2.0  -1.1
  5250   8.4  47.1  275   5  3   9.6   5.3 |   5.7  42.3  315   2  1   1.5   0.8
  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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