Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 201254
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0554 MST Saturday, January 20, 2018

This forecast is for Saturday, January 20, 2018:

If the trigger temperature of 56.8 F/13.8 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 5381 ft MSL (542 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................. 5156 ft MSL (316 ft AGL)
Thermal soaring outlook for Sunday 01/21....... Fair

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

Remarks...

Sunrise/Sunset.................... 07:29:14 / 17:20:17 MST
Total possible sunshine........... 9 hr 51 min 3 sec (591 min 3 sec)
Altitude of sun at 12:25:09 MST... 30.94 degrees

Upper air data from rawinsonde observation taken on 01/20/2018 at 0500 MST

Freezing level.................. 4839 ft MSL (0 ft AGL)
Additional freezing level....... 10006 ft MSL (5167 ft AGL)
Convective condensation level... 15489 ft MSL (10650 ft AGL)
Lifted condensation level....... 11911 ft MSL (7071 ft AGL)
Lifted index.................... +7.9
K index......................... +16.6

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  -60.1 -76.2   265   35   18   8.6   4.7  102.5 216.6    52.2      M    M
 45000  -57.5 -71.5   220   61   31  -3.3  -1.8   81.1 177.9    42.9      M    M
 40000  -62.9 -81.2   235   90   46  -8.5  -4.7   49.3 120.7    25.2      M    M
 38000  -61.2 -78.2   230   97   50   7.8   4.3   42.8 109.1    21.7      M    M
 36000  -56.6 -69.9   230  101   52   7.6   4.2   41.1 106.0    21.1      M    M
 34000  -51.9 -61.4   230   98   50   7.4   4.1   39.6 103.2    20.5      M    M
 32000  -46.9 -52.4   230   96   50   7.4   4.0   37.3  99.1    19.5      M    M
 30000  -42.4 -44.3   235   94   48   5.8   3.2   35.6  96.1    18.7      M    M
 29000  -41.0 -41.8   235   91   47   8.3   4.6   33.6  92.5    17.4      M    M
 28000  -38.6 -37.5   235   89   46   8.0   4.4   32.9  91.1    17.1      M    M
 27000  -36.3 -33.3   230   86   44   6.0   3.3   32.0  89.7    16.6      M    M
 26000  -34.5 -30.1   230   84   43   6.1   3.3   30.6  87.1    15.7      M    M
 25000  -32.7 -26.9   230   81   42   6.1   3.3   29.3  84.7    14.9      M    M
 24000  -30.9 -23.6   230   77   40   6.0   3.3   27.9  82.2    13.9      M    M
 23000  -28.8 -19.8   230   77   40   7.3   4.0   26.8  80.3    13.2      M    M
 22000  -26.7 -16.1   230   73   38   6.4   3.5   25.9  78.6    12.5      M    M
 21000  -25.0 -13.0   225   70   36   5.3   2.9   24.4  75.8    11.4      M    M
 20000  -22.9  -9.2   225   66   34   7.4   4.1   23.4  74.2    10.8      M    M
 19500  -21.4  -6.5   225   65   33  12.6   6.9   23.5  74.3    10.8      M    M
 19000  -20.1  -4.2   225   63   33   7.0   3.8   23.4  74.1    10.7      M    M
 18500  -19.0  -2.2   225   62   32   7.4   4.1   23.0  73.4    10.4      M    M
 18000  -17.8  -0.0   225   60   31   8.1   4.4   22.6  72.7    10.2      M    M
 17500  -16.2   2.8   225   58   30   5.6   3.1   21.9  71.5     9.7      M    M
 17000  -15.2   4.6   220   56   29   6.7   3.7   21.4  70.5     9.3      M    M
 16500  -14.2   6.4   220   54   28   6.8   3.7   20.9  69.6     8.9      M    M
 16000  -13.2   8.2   220   53   27   7.7   4.2   20.4  68.8     8.5      M    M
 15500  -12.0  10.4   220   52   27   8.1   4.5   20.1  68.2     8.3      M    M
 15000  -10.8  12.6   220   50   26   8.2   4.5   19.9  67.8     8.1      M    M
 14500   -9.5  14.9   220   49   25   8.1   4.4   19.6  67.3     7.9      M    M
 14000   -8.3  17.1   220   47   24   7.0   3.9   19.4  66.9     7.7      M    M
 13500   -7.4  18.7   220   43   22   5.0   2.7   18.8  65.8     7.2      M    M
 13000   -7.0  19.4   225   38   20   3.0   1.7   17.7  63.9     6.2      M    M
 12500   -6.5  20.3   225   33   17   4.9   2.7   16.7  62.1     5.3      M    M
 12000   -5.4  22.3   230   29   15   9.4   5.1   16.4  61.5     5.0      M    M
 11500   -4.0  24.8   230   28   15   9.1   5.0   16.3  61.3     4.8      M    M
 11000   -2.7  27.1   230   27   14   9.0   5.0   16.1  61.1     4.8      M    M
 10500   -1.3  29.7   230   27   14   9.0   5.0   16.0  60.9     4.7      M    M
 10250   -0.7  30.7   230   26   14   9.1   5.0   16.0  60.8     4.6      M    M
 10000    0.0  32.0   230   26   13   9.0   4.9   16.0  60.7     4.6      M    M
  9750    0.6  33.1   225   29   15   8.0   4.4   15.9  60.6     4.5      M    M
  9500    1.2  34.2   220   28   15   8.5   4.7   15.7  60.3     4.4      M    M
  9250    1.8  35.2   220   28   15   5.2   2.8   15.6  60.0     4.3      M    M
  9000    1.9  35.4   215   28   14  -1.0  -0.5   14.9  58.9     3.7      M    M
  8750    1.9  35.4   215   25   13  -1.0  -0.5   14.1  57.3     2.9      M    M
  8500    2.0  35.6   215   22   12   6.3   3.5   13.5  56.2     2.3      M    M
  8250    2.7  36.9   215   19   10  10.6   5.8   13.5  56.2     2.3      M    M
  8000    3.5  38.3   215   16    8   9.5   5.2   13.5  56.3     2.4      M    M
  7750    4.2  39.6   210   15    8   9.8   5.4   13.5  56.3     2.4      M    M
  7500    4.9  40.8   205   13    7   9.7   5.3   13.5  56.3     2.4      M    M
  7250    5.6  42.1   200   12    6   9.7   5.3   13.5  56.3     2.4      M    M
  7000    6.4  43.5   190   10    5   9.7   5.3   13.5  56.3     2.4      M    M
  6750    7.1  44.8   185   11    6   9.8   5.4   13.5  56.3     2.4      M    M
  6500    7.8  46.0   185   12    6   9.6   5.3   13.5  56.3     2.4      M    M
  6250    8.6  47.5   180   13    7  10.1   5.5   13.5  56.3     2.4      M    M
  6000    9.3  48.7   180   14    7   8.3   4.6   13.5  56.3     2.4      M    M
  5750   10.0  50.0   180   11    6  14.9   8.2   13.5  56.3     2.4      M    M
  5500   10.7  51.3   185    8    4  -9.7  -5.3   13.5  56.2     2.4      M    M
  5250    8.5  47.3   190    4    2 -39.0 -21.4   10.4  50.8    -0.6      M    M
  5000    5.9  42.6   230    1    1 -30.4 -16.7    7.1  44.7    -4.0     33  0.2

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

           01/20/2018 at 0800 MST          |       01/20/2018 at 1100 MST
                                           |
K index... +22.6  LI... +0.4               | K index... +20.3  LI... +0.4
CAPE... 0.0  CIN... -0.4                   | CAPE... +0.1  CIN... -0.4
                                           |
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 -60.3 -76.5  245  28 14   2.7   1.5 | -58.7 -73.7  235  32 17   2.4   1.3
 45000 -56.0 -68.8  235  44 23   2.8   1.6 | -54.8 -66.6  225  42 21   3.0   1.7
 40000 -58.7 -73.7  235  84 43  -2.0  -1.1 | -57.5 -71.5  230  82 42  -2.0  -1.1
 38000 -58.4 -73.1  235  96 50   5.1   2.8 | -57.5 -71.5  230  95 49   3.7   2.1
 36000 -55.3 -67.5  230 101 52   5.1   2.8 | -55.3 -67.5  225 101 52   3.8   2.1
 34000 -52.2 -62.0  230 105 54   6.1   3.3 | -53.0 -63.4  225 106 55   5.2   2.8
 32000 -48.1 -54.6  230 103 53   6.9   3.8 | -48.0 -54.4  225 104 54   7.4   4.0
 30000 -43.4 -46.1  230 100 52   7.0   3.9 | -43.6 -46.5  225 102 52   7.4   4.0
 29000 -41.3 -42.3  230  98 50   7.1   3.9 | -41.5 -42.7  225 100 51   7.2   3.9
 28000 -39.2 -38.6  235  95 49   7.1   3.9 | -39.3 -38.7  225  97 50   7.2   3.9
 27000 -37.1 -34.8  235  92 48   7.2   3.9 | -37.2 -35.0  225  95 49   7.3   4.0
 26000 -35.2 -31.4  235  88 45   6.2   3.4 | -35.3 -31.5  225  92 47   6.1   3.3
 25000 -33.3 -27.9  230  83 43   6.2   3.4 | -33.5 -28.3  225  89 46   6.1   3.3
 24000 -31.5 -24.7  230  79 40   6.1   3.4 | -31.7 -25.1  225  85 44   6.1   3.3
 23000 -29.2 -20.6  230  73 38   8.2   4.5 | -29.7 -21.5  225  81 42   7.0   3.8
 22000 -26.8 -16.2  225  68 35   8.2   4.5 | -27.6 -17.7  225  75 39   7.0   3.8
 21000 -24.3 -11.7  225  62 32   8.1   4.4 | -25.5 -13.9  220  70 36   7.0   3.8
 20000 -22.6  -8.7  225  61 31   5.3   2.9 | -23.5 -10.3  220  65 33   6.8   3.7
 19500 -21.8  -7.2  225  60 31   5.3   2.9 | -22.5  -8.5  220  63 32   6.8   3.7
 19000 -21.0  -5.8  225  60 31   5.3   2.9 | -21.5  -6.7  220  61 31   6.8   3.7
 18500 -20.2  -4.4  225  60 31   5.0   2.7 | -20.5  -4.9  220  58 30   6.8   3.7
 18000 -19.3  -2.7  225  59 30   8.1   4.4 | -19.4  -2.9  220  56 29   7.5   4.1
 17500 -18.1  -0.6  225  57 29   7.8   4.3 | -18.3  -0.9  220  53 27   7.5   4.1
 17000 -17.0   1.4  225  56 29   7.6   4.2 | -17.2   1.0  220  50 26   7.7   4.2
 16500 -15.9   3.4  225  53 27   7.5   4.1 | -16.1   3.0  220  47 24   7.8   4.3
 16000 -14.8   5.4  225  51 26   7.5   4.1 | -14.9   5.2  215  43 22   7.9   4.3
 15500 -13.7   7.3  225  48 25   7.8   4.3 | -13.7   7.3  215  40 21   7.9   4.4
 15000 -12.5   9.5  225  45 23   7.8   4.3 | -12.0  10.4  220  36 19   8.0   4.4
 14500 -10.8  12.6  225  45 23   7.9   4.3 | -10.8  12.6  220  39 20   8.2   4.5
 14000  -9.6  14.7  220  46 23   7.6   4.2 |  -9.6  14.7  225  41 21   8.2   4.5
 13500  -8.7  16.3  220  43 22   6.3   3.5 |  -8.4  16.9  225  44 23   8.2   4.5
 13000  -7.7  18.1  220  40 21   6.4   3.5 |  -7.2  19.0  220  46 24   8.2   4.5
 12500  -6.8  19.8  220  38 19   6.1   3.3 |  -6.0  21.2  220  47 24   7.3   4.0
 12000  -5.9  21.4  220  36 18   6.1   3.3 |  -4.9  23.2  220  47 24   7.4   4.1
 11500  -5.1  22.8  220  34 17   6.0   3.3 |  -3.8  25.2  220  47 24   7.5   4.1
 11000  -4.2  24.4  220  31 16   6.0   3.3 |  -2.7  27.1  220  46 24   7.5   4.1
 10500  -3.2  26.2  215  29 15   6.8   3.8 |  -1.7  28.9  215  45 23   5.2   2.8
 10250  -2.7  27.1  215  28 14   7.3   4.0 |  -1.3  29.7  215  44 23   5.4   3.0
 10000  -2.1  28.2  215  27 14   8.6   4.7 |  -0.9  30.4  210  43 22   5.4   3.0
  9750  -1.4  29.5  215  26 14   9.1   5.0 |  -0.5  31.1  210  42 22   5.7   3.1
  9500  -0.7  30.7  215  25 13   9.0   4.9 |  -0.1  31.8  205  42 21   5.9   3.2
  9250  -0.0  32.0  210  24 12   9.1   5.0 |   0.4  32.7  205  41 21   5.7   3.1
  9000   0.6  33.1  210  23 12   7.9   4.3 |   0.8  33.4  200  40 21   5.4   2.9
  8750   1.2  34.2  210  23 12   7.7   4.2 |   1.2  34.2  200  40 20   6.8   3.7
  8500   1.8  35.2  205  23 12   8.6   4.7 |   1.8  35.2  200  38 20   8.0   4.4
  8250   2.5  36.5  205  23 12   8.6   4.7 |   2.4  36.3  195  37 19   7.5   4.1
  8000   3.2  37.8  205  24 12   8.8   4.8 |   3.0  37.4  195  36 19   8.5   4.7
  7750   3.8  38.8  200  24 12   6.8   3.7 |   3.6  38.5  190  34 17   7.1   3.9
  7500   4.2  39.6  200  24 12   6.0   3.3 |   4.0  39.2  190  31 16   5.0   2.7
  7250   4.7  40.5  195  24 12   5.2   2.9 |   4.5  40.1  185  29 15   5.7   3.1
  7000   5.0  41.0  190  24 12   2.2   1.2 |   4.9  40.8  180  27 14   6.3   3.5
  6750   5.1  41.2  180  23 12   0.4   0.2 |   5.4  41.7  180  24 12   6.9   3.8
  6500   5.1  41.2  175  23 12   1.0   0.5 |   5.9  42.6  175  21 11   6.8   3.7
  6250   5.1  41.2  170  22 11  -3.4  -1.9 |   6.4  43.5  170  19 10   7.0   3.8
  6000   4.6  40.3  165  19 10  -7.2  -3.9 |   6.9  44.4  170  17  9   7.1   3.9
  5750   4.2  39.6  155  15  8  -5.1  -2.8 |   7.5  45.5  165  14  7   7.9   4.3
  5500   3.8  38.8  145  10  5  -5.2  -2.9 |   8.1  46.6  165  12  6   6.6   3.6
  5250   3.4  38.1  140   9  4  -6.0  -3.3 |   8.4  47.1  165  10  5   1.9   1.1
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           01/20/2018 at 1400 MST          |       01/20/2018 at 1700 MST
                                           |
K index... +21.1  LI... -0.5               | K index... +21.9  LI... +1.6
CAPE... +16.4  CIN... -26.5                | 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 -56.7 -70.1  240  28 14   3.5   1.9 | -55.8 -68.4  240  45 23   3.7   2.0
 45000 -51.5 -60.7  220  35 18   4.0   2.2 | -50.2 -58.4  235  60 31   3.9   2.1
 40000 -55.8 -68.4  225  80 41  -3.4  -1.8 | -52.7 -62.9  220  77 39  -2.1  -1.2
 38000 -56.9 -70.4  225  95 49   2.7   1.5 | -53.7 -64.7  215  85 44   0.2   0.1
 36000 -55.1 -67.2  220 101 52   2.9   1.6 | -53.6 -64.5  210  99 51   0.1   0.1
 34000 -53.0 -63.4  215 108 55   5.8   3.2 | -53.6 -64.5  210 110 57   1.4   0.8
 32000 -48.5 -55.3  215 106 54   7.5   4.1 | -49.7 -57.5  210 110 57   6.9   3.8
 30000 -44.1 -47.4  215 104 53   7.4   4.0 | -45.5 -49.9  210 109 56   7.1   3.9
 29000 -42.0 -43.6  215 102 52   7.0   3.8 | -43.4 -46.1  210 107 55   7.1   3.9
 28000 -39.9 -39.8  220  99 51   7.0   3.8 | -41.2 -42.2  215 104 54   7.1   3.9
 27000 -37.8 -36.0  220  97 50   7.0   3.8 | -39.1 -38.4  215 102 53   7.1   3.9
 26000 -35.8 -32.4  220  95 49   6.6   3.6 | -37.2 -35.0  215  99 51   5.3   2.9
 25000 -33.8 -28.8  220  92 48   6.6   3.6 | -35.6 -32.1  215  95 49   5.4   3.0
 24000 -31.8 -25.2  220  90 46   6.6   3.6 | -34.0 -29.2  220  91 47   5.4   3.0
 23000 -29.9 -21.8  220  86 44   6.3   3.5 | -32.2 -26.0  220  86 44   7.5   4.1
 22000 -28.0 -18.4  220  81 42   6.3   3.5 | -30.0 -22.0  220  76 39   7.4   4.1
 21000 -26.1 -15.0  220  76 39   6.3   3.5 | -27.8 -18.0  220  67 34   7.4   4.1
 20000 -23.7 -10.7  220  71 36   6.4   3.5 | -24.8 -12.6  220  57 30   8.6   4.7
 19500 -22.8  -9.0  220  69 35   6.4   3.5 | -23.5 -10.3  220  54 28   8.6   4.7
 19000 -21.8  -7.2  220  67 34   6.4   3.5 | -22.2  -8.0  215  51 26   8.6   4.7
 18500 -20.9  -5.6  220  65 33   6.4   3.5 | -21.0  -5.8  215  48 25   8.7   4.8
 18000 -19.8  -3.6  220  63 32   8.0   4.4 | -19.7  -3.5  215  46 24   8.0   4.4
 17500 -18.7  -1.7  220  61 32   7.9   4.3 | -18.5  -1.3  215  45 23   8.0   4.4
 17000 -17.5   0.5  220  60 31   8.1   4.4 | -17.4   0.7  210  44 23   7.8   4.3
 16500 -16.3   2.7  220  58 30   8.1   4.5 | -16.2   2.8  210  44 23   7.6   4.2
 16000 -15.1   4.8  220  57 29   8.2   4.5 | -15.1   4.8  210  44 23   7.6   4.1
 15500 -13.9   7.0  220  55 28   8.2   4.5 | -14.1   6.6  210  44 23   6.7   3.7
 15000 -12.7   9.1  220  53 27   8.2   4.5 | -13.1   8.4  210  44 23   6.8   3.7
 14500 -11.5  11.3  220  51 26   8.2   4.5 | -12.2  10.0  210  45 23   6.3   3.4
 14000 -10.3  13.5  220  49 25   8.2   4.5 | -11.2  11.8  210  46 24   6.3   3.5
 13500  -9.1  15.6  220  47 24   8.0   4.4 | -10.4  13.3  210  46 24   5.6   3.0
 13000  -7.9  17.8  220  44 23   8.0   4.4 |  -9.6  14.7  205  44 23   5.4   3.0
 12500  -6.8  19.8  220  42 22   7.6   4.2 |  -8.8  16.2  205  42 22   5.7   3.1
 12000  -5.7  21.7  220  42 21   7.6   4.2 |  -7.9  17.8  205  42 22   5.8   3.2
 11500  -4.6  23.7  220  41 21   7.1   3.9 |  -7.1  19.2  205  42 22   5.8   3.2
 11000  -3.6  25.5  220  42 22   7.1   3.9 |  -6.2  20.8  200  41 21   5.7   3.2
 10500  -2.7  27.1  215  42 21   4.9   2.7 |  -5.4  22.3  200  40 21   5.6   3.1
 10250  -2.3  27.9  210  40 21   4.6   2.5 |  -5.0  23.0  200  39 20   5.6   3.0
 10000  -2.0  28.4  210  39 20   4.7   2.6 |  -4.6  23.7  200  38 20   5.8   3.2
  9750  -1.6  29.1  205  38 19   5.7   3.1 |  -4.2  24.4  200  38 19   6.2   3.4
  9500  -1.1  30.0  205  36 19   6.6   3.6 |  -3.7  25.3  200  36 19   6.3   3.5
  9250  -0.6  30.9  200  35 18   7.5   4.1 |  -3.2  26.2  205  35 18   6.8   3.7
  9000  -0.1  31.8  200  33 17   4.7   2.6 |  -2.8  27.0  205  33 17   5.6   3.1
  8750   0.2  32.4  200  32 17   7.0   3.8 |  -2.4  27.7  205  32 16   5.5   3.0
  8500   1.0  33.8  200  32 16  11.3   6.2 |  -1.9  28.6  205  30 15   6.9   3.8
  8250   1.8  35.2  200  31 16  10.9   6.0 |  -1.4  29.5  210  27 14   7.7   4.2
  8000   2.6  36.7  200  31 16   8.9   4.9 |  -0.9  30.4  210  25 13   5.1   2.8
  7750   3.2  37.8  200  30 16   8.3   4.6 |  -0.6  30.9  215  23 12   4.8   2.6
  7500   3.9  39.0  195  30 15  10.3   5.6 |  -0.1  31.8  220  21 11   7.2   4.0
  7250   4.7  40.5  195  29 15   9.8   5.4 |   0.4  32.7  225  20 10   6.6   3.6
  7000   5.4  41.7  195  28 15   9.9   5.4 |   0.9  33.6  230  18  9   6.7   3.7
  6750   6.2  43.2  195  28 14  10.0   5.5 |   1.3  34.3  240  16  8   7.1   3.9
  6500   6.9  44.4  195  27 14  10.0   5.5 |   1.9  35.4  245  15  7   7.5   4.1
  6250   7.7  45.9  195  26 13  10.2   5.6 |   2.4  36.3  250  13  7   7.5   4.1
  6000   8.4  47.1  195  24 13   9.4   5.1 |   3.0  37.4  260  12  6   6.4   3.5
  5750   9.2  48.6  200  23 12  12.4   6.8 |   3.5  38.3  260  11  6   8.7   4.8
  5500  10.4  50.7  200  21 11  19.7  10.8 |   4.4  39.9  265  10  5  15.4   8.4
  5250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  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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