Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 011234
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0634 MDT Wednesday, April 1, 2015

This forecast is for Wednesday, April 1, 2015:

If the trigger temperature of 68.4 F/20.2 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 676 ft/min (3.4 m/s)
   Maximum height of thermals.................. 14187 ft MSL (9348 ft AGL)

Forecast maximum temperature................... 70.0 F/21.6 C
Time of trigger temperature.................... 1430 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 6016 ft MSL (1176 ft AGL)
Thermal soaring outlook for Thursday 04/02..... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:58:56 / 19:36:44 MDT
Total possible sunshine........... 12 hr 37 min 47 sec (757 min 47 sec)
Altitude of sun at 13:17:59 MDT... 55.53 degrees

Upper air data from rawinsonde observation taken on 04/01/2015 at 0600 MDT

Freezing level.................. 11801 ft MSL (6962 ft AGL)
Convective condensation level... 16798 ft MSL (11959 ft AGL)
Lifted condensation level....... 16517 ft MSL (11678 ft AGL)
Lifted index.................... -0.3
K index......................... +17.6

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -58.4 -73.1   250   35   18   2.4   1.3  104.4 220.0    47.4      M    M
 45000  -55.7 -68.3   235   41   21   3.0   1.6   83.0 181.4    37.8      M    M
 40000  -59.5 -75.1   240   48   25  -6.1  -3.4   54.1 129.4    21.6      M    M
 38000  -61.2 -78.2   245   51   26   4.7   2.6   42.6 108.8    14.5      M    M
 36000  -58.5 -73.3   250   55   28   4.3   2.4   38.0 100.4    11.7      M    M
 34000  -54.6 -66.3   255   60   31   6.0   3.3   35.2  95.3    10.0      M    M
 32000  -49.5 -57.1   260   56   29   8.1   4.4   33.0  91.5     8.7      M    M
 30000  -44.8 -48.6   260   53   27   7.7   4.2   31.6  88.9     7.9      M    M
 29000  -42.1 -43.8   260   49   25   9.2   5.0   31.3  88.4     7.7      M    M
 28000  -39.3 -38.7   265   45   23   9.2   5.0   31.2  88.1     7.7      M    M
 27000  -36.6 -33.9   260   45   23   9.1   5.0   30.9  87.6     7.6      M    M
 26000  -34.3 -29.7   250   46   24   6.1   3.4   30.0  86.0     7.0      M    M
 25000  -32.7 -26.9   245   47   24   3.6   2.0   28.4  83.2     5.8      M    M
 24000  -31.1 -24.0   235   48   25   8.7   4.8   26.8  80.2     4.6      M    M
 23000  -29.2 -20.6   230   45   23   4.3   2.4   25.5  78.0     3.6      M    M
 22000  -26.7 -16.1   225   41   21   8.3   4.6   25.1  77.2     3.2      M    M
 21000  -24.5 -12.1   220   38   20   6.8   3.7   24.2  75.6     2.5      M    M
 20000  -22.2  -8.0   225   34   18  11.5   6.3   23.5  74.4     1.9      M    M
 19500  -20.9  -5.6   230   30   16   7.6   4.2   23.5  74.3     1.8      M    M
 19000  -19.7  -3.5   235   26   13   8.0   4.4   23.2  73.7     1.6      M    M
 18500  -18.5  -1.3   240   22   11   7.9   4.3   22.9  73.2     1.3      M    M
 18000  -17.3   0.9   240   22   11   8.9   4.9   22.7  72.8     1.1      M    M
 17500  -15.3   4.5   250   23   12   8.8   4.8   22.4  72.3     0.9      M    M
 17000  -14.0   6.8   255   24   12   8.8   4.8   22.3  72.1     0.7      M    M
 16500  -12.6   9.3   260   26   13   8.8   4.8   22.1  71.8     0.6      M    M
 16000  -11.3  11.7   265   27   14   8.8   4.8   22.0  71.6     0.5      M    M
 15500  -10.0  14.0   265   26   14   8.9   4.9   21.8  71.3     0.3      M    M
 15000   -8.7  16.3   265   26   13   8.9   4.9   21.7  71.0     0.2      M    M
 14500   -7.4  18.7   265   25   13   8.9   4.9   21.5  70.7     0.1      M    M
 14000   -6.1  21.0   265   25   13   8.9   4.9   21.4  70.5    -0.1    848  4.3
 13500   -4.7  23.5   260   25   13   9.1   5.0   21.3  70.3    -0.2    794  4.0
 13000   -3.3  26.1   260   26   13   9.5   5.2   21.2  70.2    -0.3    737  3.7
 12500   -1.9  28.6   255   26   14   9.5   5.2   21.2  70.1    -0.3    679  3.5
 12000   -0.5  31.1   255   27   14   9.5   5.2   21.2  70.1    -0.3    622  3.2
 11500    0.9  33.6   255   27   14   9.5   5.2   21.1  70.0    -0.4    565  2.9
 11000    2.4  36.3   255   27   14   9.5   5.2   21.0  69.9    -0.5    507  2.6
 10500    3.8  38.8   255   27   14   9.5   5.2   21.0  69.8    -0.5    450  2.3
 10250    4.5  40.1   255   27   14   9.6   5.3   21.0  69.8    -0.5    421  2.1
 10000    5.2  41.4   255   27   14   9.1   5.0   21.0  69.8    -0.5    393  2.0
  9750    5.8  42.4   255   27   14   8.7   4.8   20.9  69.6    -0.6    366  1.9
  9500    6.5  43.7   255   27   14   8.8   4.8   20.8  69.5    -0.7    339  1.7
  9250    7.1  44.8   250   28   14   8.8   4.8   20.8  69.4    -0.7    312  1.6
  9000    7.8  46.0   250   28   14   8.8   4.8   20.7  69.3    -0.8    285  1.4
  8750    8.5  47.3   250   26   14   8.8   4.8   20.6  69.1    -0.9    258  1.3
  8500    9.1  48.4   250   25   13   8.8   4.8   20.5  69.0    -1.0    231  1.2
  8250    9.8  49.6   245   23   12   8.8   4.8   20.5  68.9    -1.1    204  1.0
  8000   10.4  50.7   245   21   11   8.8   4.8   20.4  68.7    -1.1    177  0.9
  7750   11.1  52.0   245   21   11   8.8   4.8   20.3  68.6    -1.2    150  0.8
  7500   11.7  53.1   245   21   11   8.6   4.7   20.2  68.4    -1.3    123  0.6
  7250   12.4  54.3   240   20   10   9.2   5.1   20.2  68.3    -1.4     96  0.5
  7000   13.0  55.4   240   20   10   6.8   3.7   20.1  68.1    -1.5     70  0.4
  6750   13.4  56.1   240   17    9   4.4   2.4   19.7  67.5    -1.8     51  0.3
  6500   13.8  56.8   240   14    7   5.1   2.8   19.3  66.8    -2.2     33  0.2
  6250   14.1  57.4   235   11    6   5.0   2.7   19.0  66.2    -2.6     14  0.1
  6000   14.5  58.1   230    8    4   4.7   2.6   18.6  65.5    -2.9      M    M
  5750   14.9  58.8   225    5    3   5.7   3.1   18.3  64.9    -3.3      M    M
  5500   15.2  59.4   205    3    2   2.1   1.1   17.9  64.2    -3.7      M    M
  5250   15.1  59.2   145    2    1  -3.5  -1.9   17.1  62.7    -4.5      M    M
  5000   14.6  58.3   100    4    2 -11.5  -6.3   15.8  60.5    -5.7      M    M

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

           04/01/2015 at 0900 MDT          |       04/01/2015 at 1200 MDT
                                           |
K index... +14.9  LI... +1.4               | K index... +17.6  LI... +0.6
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -3.5
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -57.9 -72.2  260  30 15   1.9   1.1 | -56.9 -70.4  250  33 17   2.1   1.1
 45000 -54.9 -66.8  245  45 23   0.8   0.4 | -53.6 -64.5  245  45 23   0.9   0.5
 40000 -56.7 -70.1  250  48 24  -1.2  -0.7 | -56.1 -69.0  245  52 27  -1.7  -0.9
 38000 -56.8 -70.2  250  48 25   1.2   0.6 | -56.6 -69.9  245  54 28   0.5   0.3
 36000 -56.1 -69.0  255  49 25   1.2   0.6 | -56.3 -69.3  245  54 28   0.5   0.3
 34000 -55.1 -67.2  255  49 25   7.0   3.8 | -55.8 -68.4  245  54 28   6.1   3.3
 32000 -49.9 -57.8  255  48 25   7.8   4.3 | -50.5 -58.9  245  53 28   7.9   4.4
 30000 -45.2 -49.4  255  46 24   7.8   4.3 | -45.7 -50.3  245  53 27   8.1   4.5
 29000 -42.8 -45.0  255  44 23   7.8   4.3 | -43.2 -45.8  245  52 27   8.2   4.5
 28000 -40.5 -40.9  250  42 22   7.8   4.3 | -40.8 -41.4  245  51 26   8.2   4.5
 27000 -38.1 -36.6  250  40 21   7.8   4.3 | -38.3 -36.9  250  50 26   8.0   4.4
 26000 -35.8 -32.4  250  41 21   7.8   4.3 | -36.0 -32.8  250  49 25   7.6   4.2
 25000 -33.4 -28.1  250  41 21   7.8   4.3 | -33.7 -28.7  250  48 25   7.6   4.2
 24000 -31.1 -24.0  250  41 21   7.7   4.2 | -31.4 -24.5  250  47 24   7.5   4.1
 23000 -28.9 -20.0  255  42 21   7.3   4.0 | -29.4 -20.9  250  44 23   6.6   3.6
 22000 -26.7 -16.1  255  42 22   7.3   4.0 | -27.4 -17.3  255  40 21   6.7   3.7
 21000 -24.5 -12.1  255  42 22   7.7   4.2 | -25.4 -13.7  255  37 19   7.6   4.2
 20000 -22.1  -7.8  255  40 21   8.0   4.4 | -23.0  -9.4  255  36 19   8.2   4.5
 19500 -20.9  -5.6  255  39 20   8.0   4.4 | -21.8  -7.2  255  36 18   8.2   4.5
 19000 -19.8  -3.6  255  38 20   8.0   4.4 | -20.5  -4.9  255  35 18   8.3   4.5
 18500 -18.6  -1.5  255  37 19   7.9   4.3 | -19.3  -2.7  255  35 18   8.5   4.6
 18000 -17.4   0.7  255  35 18   7.8   4.3 | -18.0  -0.4  255  34 18   8.8   4.8
 17500 -16.3   2.7  250  33 17   7.8   4.3 | -16.7   1.9  255  33 17   8.8   4.8
 17000 -15.1   4.8  250  30 16   7.9   4.3 | -15.5   4.1  250  31 16   8.4   4.6
 16500 -14.0   6.8  250  28 14   7.8   4.3 | -14.2   6.4  250  30 15   8.4   4.6
 16000 -12.8   9.0  250  26 13   8.9   4.9 | -13.0   8.6  250  28 14   8.2   4.5
 15500 -11.4  11.5  250  24 12   9.2   5.1 | -11.8  10.8  250  27 14   8.2   4.5
 15000  -9.3  15.3  255  23 12   9.4   5.2 |  -9.9  14.2  250  26 13   9.2   5.1
 14500  -7.9  17.8  255  22 11   9.4   5.2 |  -8.5  16.7  250  26 13   9.3   5.1
 14000  -6.5  20.3  255  22 11   9.1   5.0 |  -7.2  19.0  250  25 13   8.8   4.8
 13500  -5.2  22.6  255  22 11   9.0   4.9 |  -5.9  21.4  250  24 13   8.7   4.7
 13000  -3.8  25.2  260  22 12   8.7   4.8 |  -4.6  23.7  250  24 12   8.4   4.6
 12500  -2.6  27.3  255  22 11   8.5   4.7 |  -3.4  25.9  250  23 12   8.2   4.5
 12000  -1.3  29.7  255  21 11   8.0   4.4 |  -2.2  28.0  245  22 12   7.7   4.2
 11500  -0.2  31.6  255  20 10   7.4   4.1 |  -1.1  30.0  250  21 11   7.1   3.9
 11000   0.9  33.6  250  18  9   6.5   3.5 |  -0.0  32.0  250  20 10   6.1   3.4
 10500   1.8  35.2  255  17  9   5.3   2.9 |   0.7  33.3  250  18  9   4.9   2.7
 10250   2.2  36.0  255  16  8   7.0   3.9 |   1.1  34.0  250  17  9   6.2   3.4
 10000   2.7  36.9  255  16  8   7.2   4.0 |   1.6  34.9  255  16  8   6.0   3.3
  9750   3.2  37.8  255  16  8   5.5   3.0 |   1.9  35.4  255  15  8   4.3   2.4
  9500   3.6  38.5  260  16  8   5.8   3.2 |   2.2  36.0  260  14  7   4.9   2.7
  9250   4.0  39.2  260  16  8   6.3   3.5 |   2.6  36.7  265  12  6   4.4   2.4
  9000   4.5  40.1  260  15  8   5.4   3.0 |   2.9  37.2  265  11  6   4.8   2.6
  8750   4.8  40.6  265  14  7   4.1   2.3 |   3.3  37.9  270  10  5   5.7   3.1
  8500   5.1  41.2  265  14  7   4.5   2.5 |   3.7  38.7  275   9  5   5.1   2.8
  8250   5.5  41.9  265  13  7   4.3   2.4 |   4.1  39.4  280   8  4   6.4   3.5
  8000   5.8  42.4  270  13  7   4.3   2.4 |   4.6  40.3  280   8  4   8.4   4.6
  7750   6.1  43.0  270  12  6   4.4   2.4 |   5.3  41.5  280   8  4   8.7   4.8
  7500   6.4  43.5  275  12  6   4.4   2.4 |   5.9  42.6  285   7  4   8.5   4.7
  7250   6.7  44.1  275  11  6   4.6   2.5 |   6.6  43.9  285   7  4  10.0   5.5
  7000   7.1  44.8  275  10  5   4.7   2.6 |   7.4  45.3  280   7  4  11.0   6.0
  6750   7.4  45.3  270   9  4   5.0   2.7 |   8.1  46.6  280   7  4   9.6   5.3
  6500   7.8  46.0  265   7  4   4.5   2.5 |   8.9  48.0  280   7  4  10.0   5.5
  6250   8.1  46.6  255   6  3   3.3   1.8 |   9.7  49.5  280   7  4  11.2   6.1
  6000   8.3  46.9  240   4  2   3.1   1.7 |  10.5  50.9  280   7  3  11.3   6.2
  5750   8.5  47.3  215   3  2   3.4   1.9 |  11.3  52.3  280   7  3  11.3   6.2
  5500   8.7  47.7  185   3  1   5.5   3.0 |  12.2  54.0  280   7  3  13.3   7.3
  5250   9.2  48.6  190   3  1   8.5   4.7 |  13.3  55.9  280   7  3  16.1   8.8
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/01/2015 at 1500 MDT          |       04/01/2015 at 1800 MDT
                                           |
K index... +20.4  LI... -1.1               | K index... -8.8  LI... +0.6
CAPE... +55.2  CIN... -81.6                | CAPE... 0.0  CIN... -17.8
                                           |
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 -56.2 -69.2  245  35 18   2.2   1.2 | -55.4 -67.7  250  32 16   1.9   1.0
 45000 -52.8 -63.0  250  48 24   1.2   0.7 | -52.4 -62.3  255  47 24   1.1   0.6
 40000 -54.5 -66.1  260  60 31  -1.2  -0.7 | -55.4 -67.7  270  69 35  -2.1  -1.1
 38000 -55.1 -67.2  260  63 32  -0.5  -0.3 | -56.1 -69.0  270  76 39   0.4   0.2
 36000 -55.4 -67.7  255  60 31  -0.5  -0.3 | -55.9 -68.6  275  81 41   0.3   0.2
 34000 -55.6 -68.1  255  58 30   3.8   2.1 | -55.7 -68.3  275  85 44   3.7   2.0
 32000 -51.6 -60.9  255  57 29   6.6   3.6 | -51.7 -61.1  275  79 41   6.6   3.6
 30000 -47.0 -52.6  250  56 29   8.2   4.5 | -47.2 -53.0  270  72 37   7.7   4.2
 29000 -44.5 -48.1  255  55 28   8.2   4.5 | -44.9 -48.8  270  67 34   7.6   4.2
 28000 -42.1 -43.8  255  53 28   8.2   4.5 | -42.6 -44.7  265  61 32   7.6   4.2
 27000 -39.6 -39.3  255  52 27   8.1   4.4 | -40.3 -40.5  265  56 29   7.6   4.2
 26000 -37.3 -35.1  255  51 26   7.9   4.3 | -38.0 -36.4  265  54 28   7.7   4.2
 25000 -34.9 -30.8  255  50 26   7.9   4.3 | -35.7 -32.3  265  52 27   7.7   4.2
 24000 -32.5 -26.5  255  49 25   7.9   4.3 | -33.4 -28.1  260  51 26   7.7   4.2
 23000 -30.2 -22.4  255  47 24   7.8   4.3 | -31.0 -23.8  260  49 25   8.0   4.4
 22000 -27.9 -18.2  255  44 23   7.8   4.3 | -28.6 -19.5  260  47 24   8.0   4.4
 21000 -25.6 -14.1  255  41 21   7.5   4.1 | -26.2 -15.2  260  45 23   8.3   4.5
 20000 -23.4 -10.1  255  39 20   7.4   4.1 | -23.7 -10.7  260  43 22   8.5   4.7
 19500 -22.3  -8.1  255  38 19   7.5   4.1 | -22.4  -8.3  265  41 21   8.5   4.7
 19000 -21.2  -6.2  250  37 19   7.6   4.2 | -21.1  -6.0  265  40 21   8.5   4.7
 18500 -20.1  -4.2  250  36 18   8.0   4.4 | -19.9  -3.8  265  39 20   8.7   4.8
 18000 -18.8  -1.8  250  35 18   8.7   4.8 | -18.5  -1.3  265  38 20   9.0   4.9
 17500 -17.5   0.5  250  34 18   8.7   4.8 | -17.2   1.0  265  37 19   9.1   5.0
 17000 -16.2   2.8  250  34 17   9.6   5.3 | -15.9   3.4  265  36 19   7.8   4.3
 16500 -14.8   5.4  250  33 17   9.5   5.2 | -14.7   5.5  265  36 18   7.9   4.3
 16000 -13.4   7.9  250  33 17   9.2   5.0 | -13.5   7.7  260  35 18   8.3   4.6
 15500 -12.0  10.4  250  33 17   9.0   5.0 | -12.2  10.0  260  34 18   8.5   4.7
 15000 -10.7  12.7  255  32 17   8.9   4.9 | -11.0  12.2  260  34 17   8.5   4.7
 14500  -8.7  16.3  250  31 16   8.8   4.8 |  -9.1  15.6  260  33 17   8.4   4.6
 14000  -7.4  18.7  250  30 16   8.7   4.8 |  -7.8  18.0  260  33 17   8.8   4.8
 13500  -6.1  21.0  250  29 15   8.7   4.8 |  -6.4  20.5  260  32 17   8.9   4.9
 13000  -4.9  23.2  245  29 15   8.3   4.5 |  -5.1  22.8  260  32 16   8.8   4.9
 12500  -3.7  25.3  245  27 14   8.0   4.4 |  -3.8  25.2  260  31 16   8.8   4.8
 12000  -2.5  27.5  245  26 13   8.1   4.4 |  -2.5  27.5  260  31 16   8.8   4.8
 11500  -1.3  29.7  250  24 12   8.2   4.5 |  -1.2  29.8  260  30 15   8.7   4.8
 11000  -0.1  31.8  250  23 12   7.3   4.0 |   0.1  32.2  260  29 15   8.4   4.6
 10500   0.9  33.6  255  21 11   6.1   3.4 |   1.3  34.3  260  28 14   7.6   4.2
 10250   1.3  34.3  255  20 10   7.8   4.3 |   1.9  35.4  260  27 14   9.7   5.3
 10000   1.9  35.4  255  19 10   7.7   4.2 |   2.6  36.7  260  26 14   9.6   5.3
  9750   2.4  36.3  260  17  9   5.9   3.2 |   3.2  37.8  260  25 13   7.5   4.1
  9500   2.8  37.0  260  15  8   6.3   3.5 |   3.8  38.8  260  23 12   8.3   4.5
  9250   3.3  37.9  265  14  7   6.5   3.5 |   4.3  39.7  265  22 11   7.5   4.1
  9000   3.8  38.8  270  13  7   7.7   4.2 |   4.9  40.8  265  20 11   7.7   4.2
  8750   4.4  39.9  270  12  6   8.5   4.7 |   5.4  41.7  265  19 10   8.6   4.7
  8500   5.0  41.0  275  12  6   7.9   4.3 |   6.0  42.8  265  18  9   8.0   4.4
  8250   5.6  42.1  275  11  6   9.6   5.3 |   6.6  43.9  265  17  9   9.7   5.3
  8000   6.4  43.5  275  11  6  10.6   5.8 |   7.4  45.3  270  16  8  10.3   5.6
  7750   7.2  45.0  275  11  6   9.4   5.1 |   8.1  46.6  270  16  8   9.0   4.9
  7500   7.9  46.2  275  11  6   9.1   5.0 |   8.8  47.8  270  16  8   8.9   4.9
  7250   8.6  47.5  275  11  5  10.4   5.7 |   9.4  48.9  270  15  8   9.7   5.3
  7000   9.4  48.9  275  11  6  11.1   6.1 |  10.2  50.4  270  15  8  10.3   5.7
  6750  10.2  50.4  275  11  5   9.7   5.3 |  10.9  51.6  270  15  8   9.6   5.2
  6500  10.9  51.6  275  10  5  10.0   5.5 |  11.7  53.1  270  15  7   9.7   5.3
  6250  11.7  53.1  275  10  5  11.3   6.2 |  12.4  54.3  270  14  7  10.6   5.8
  6000  12.5  54.5  275  10  5  11.7   6.4 |  13.2  55.8  275  14  7  10.8   5.9
  5750  13.4  56.1  275  10  5  11.1   6.1 |  14.0  57.2  275  13  7  10.8   5.9
  5500  14.3  57.7  275   9  5  13.4   7.3 |  14.8  58.6  275  12  6   9.8   5.4
  5250  15.4  59.7  280  10  5  18.1   9.9 |  15.4  59.7  275  12  6   7.5   4.1
  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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