Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 231243
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0643 MDT Monday, April 23, 2018

This forecast is for Monday, April 23, 2018:

If the trigger temperature of 70.1 F/21.2 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1312 ft/min (6.7 m/s)
   Maximum height of thermals.................. 20302 ft MSL (15463 ft AGL)

Forecast maximum temperature................... 78.0 F/26.0 C
Time of trigger temperature.................... 1130 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 12989 ft MSL (8150 ft AGL)
Thermal soaring outlook for Tuesday 04/24...... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:26:08 / 19:58:29 MDT
Total possible sunshine........... 13 hr 32 min 22 sec (812 min 22 sec)
Altitude of sun at 13:12:28 MDT... 63.59 degrees

Upper air data from rawinsonde observation taken on 04/23/2018 at 0600 MDT

Freezing level.................. 12251 ft MSL (7412 ft AGL)
Convective condensation level... 15662 ft MSL (10823 ft AGL)
Lifted condensation level....... 16589 ft MSL (11750 ft AGL)
Lifted index.................... -0.6
K index......................... +18.5

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  -60.1 -76.2   270   27   14  -6.7  -3.7  100.0 212.0    42.5      M    M
 45000  -57.2 -71.0   275   36   19   3.6   2.0   80.1 176.3    33.4      M    M
 40000  -63.9 -83.0   245   34   17   5.0   2.7   46.6 115.8    13.8      M    M
 38000  -59.6 -75.3   240   37   19   5.5   3.0   44.2 111.5    12.5      M    M
 36000  -56.1 -69.0   245   38   20   8.1   4.4   40.6 105.1    10.4      M    M
 34000  -50.9 -59.6   250   42   21   6.4   3.5   38.7 101.7     9.4      M    M
 32000  -46.4 -51.5   245   36   19   8.9   4.9   36.8  98.2     8.2      M    M
 30000  -41.2 -42.2   250   33   17   8.5   4.7   36.1  96.9     7.9      M    M
 29000  -38.7 -37.7   250   32   17   8.0   4.4   35.5  96.0     7.6      M    M
 28000  -36.4 -33.5   250   31   16   7.7   4.2   34.6  94.2     6.9      M    M
 27000  -34.1 -29.4   245   31   16   7.7   4.2   33.7  92.7     6.3      M    M
 26000  -31.8 -25.2   245   30   15   7.6   4.1   33.0  91.5     5.8      M    M
 25000  -29.2 -20.6   245   29   15   8.7   4.8   32.6  90.8     5.6      M    M
 24000  -26.6 -15.9   255   32   16   9.3   5.1   32.3  90.1     5.4      M    M
 23000  -24.6 -12.3   260   31   16   6.0   3.3   31.1  87.9     4.5      M    M
 22000  -23.5 -10.3   260   30   15  -2.8  -1.5   28.9  84.0     2.7      M    M
 21000  -22.2  -8.0   265   29   15   5.4   3.0   27.0  80.6     1.0      M    M
 20000  -20.6  -5.1   270   28   14   6.3   3.5   25.5  77.9    -0.2   1497  7.6
 19500  -19.5  -3.1   275   26   14   8.3   4.6   25.2  77.3    -0.5   1447  7.4
 19000  -17.6   0.3   280   24   12   8.5   4.7   24.8  76.6    -0.9   1370  7.0
 18500  -16.3   2.7   280   23   12   8.8   4.8   24.6  76.3    -1.1   1316  6.7
 18000  -15.0   5.0   275   23   12   8.8   4.8   24.4  76.0    -1.3   1263  6.4
 17500  -13.7   7.3   275   22   11   8.8   4.8   24.3  75.7    -1.5   1209  6.1
 17000  -12.4   9.7   270   22   11   9.3   5.1   24.2  75.5    -1.6   1154  5.9
 16500  -11.0  12.2   265   21   11   9.2   5.1   24.1  75.3    -1.7   1098  5.6
 16000   -9.6  14.7   265   21   11   8.9   4.9   24.0  75.2    -1.8   1042  5.3
 15500   -8.4  16.9   260   21   11   8.3   4.6   23.8  74.8    -2.0    989  5.0
 15000   -7.2  19.0   255   21   11   8.5   4.7   23.5  74.3    -2.2    937  4.8
 14500   -6.0  21.2   255   21   11   7.3   4.0   23.2  73.8    -2.6    889  4.5
 14000   -4.8  23.4   250   21   11   9.3   5.1   23.0  73.4    -2.8    836  4.2
 13500   -3.4  25.9   250   19   10   9.2   5.0   22.9  73.2    -2.9    780  4.0
 13000   -2.0  28.4   250   18    9   9.1   5.0   22.8  73.0    -3.0    724  3.7
 12500   -0.6  30.9   250   16    8   9.1   5.0   22.7  72.8    -3.1    668  3.4
 12000    0.8  33.4   250   15    8   9.1   5.0   22.6  72.7    -3.2    612  3.1
 11500    2.1  35.8   245   15    8   9.0   4.9   22.5  72.4    -3.3    557  2.8
 11000    3.4  38.1   245   14    7   9.0   4.9   22.3  72.2    -3.5    502  2.5
 10500    4.8  40.6   240   14    7   9.0   5.0   22.2  72.0    -3.6    447  2.3
 10250    5.4  41.7   240   14    7   8.9   4.9   22.2  72.0    -3.7    419  2.1
 10000    6.1  43.0   235   12    6   8.7   4.8   22.1  71.8    -3.7    392  2.0
  9750    6.7  44.1   235   12    6   8.7   4.8   22.0  71.7    -3.8    366  1.9
  9500    7.4  45.3   240   11    6   8.7   4.8   22.0  71.5    -3.9    339  1.7
  9250    8.0  46.4   240   11    5   8.7   4.8   21.9  71.4    -4.0    312  1.6
  9000    8.7  47.7   245   10    5   8.7   4.8   21.8  71.3    -4.1    285  1.5
  8750    9.3  48.7   240    9    5   8.7   4.8   21.7  71.1    -4.2    259  1.3
  8500   10.0  50.0   230    8    4   8.7   4.8   21.6  70.9    -4.3    232  1.2
  8250   10.6  51.1   220    7    4   8.7   4.8   21.6  70.8    -4.4    205  1.0
  8000   11.2  52.2   205    7    4   8.9   4.9   21.5  70.7    -4.5    179  0.9
  7750   11.8  53.2   190    7    4   6.3   3.5   21.3  70.4    -4.7    153  0.8
  7500   12.2  54.0   175    8    4   4.2   2.3   21.0  69.7    -5.1    136  0.7
  7250   12.5  54.5   165   10    5   4.7   2.6   20.6  69.0    -5.5    118  0.6
  7000   12.9  55.2   155   12    6   4.9   2.7   20.2  68.3    -5.9    101  0.5
  6750   13.2  55.8   150   14    7   3.7   2.0   19.8  67.6    -6.3     83  0.4
  6500   13.3  55.9   150   16    8  -1.3  -0.7   19.1  66.5    -6.9     73  0.4
  6250   13.1  55.6   145   19   10  -3.3  -1.8   18.2  64.7    -7.9     73  0.4
  6000   12.8  55.0   145   21   11  -3.7  -2.0   17.2  62.9    -8.9     72  0.4
  5750   12.7  54.9   140   20   10   2.9   1.6   16.3  61.3    -9.8     70  0.4
  5500   13.2  55.8   135   16    8   7.7   4.2   16.1  61.0   -10.1     46  0.2
  5250   13.7  56.7   125   13    7   9.6   5.3   15.9  60.6   -10.3     23  0.1
  5000   14.3  57.7   110   11    6  -2.6  -1.5   15.7  60.3   -10.5      M    M

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

           04/23/2018 at 0900 MDT          |       04/23/2018 at 1200 MDT
                                           |
K index... +17.9  LI... -1.0               | K index... +18.7  LI... +0.3
CAPE... +53.3  CIN... -20.1                | CAPE... +0.4  CIN... -0.5
                                           |
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 -58.7 -73.7  265  30 16   1.2   0.7 | -58.3 -72.9  265  31 16   1.1   0.6
 45000 -57.2 -71.0  260  36 18  -2.5  -1.4 | -56.9 -70.4  265  34 17  -2.6  -1.4
 40000 -60.3 -76.5  255  33 17  -2.1  -1.2 | -60.8 -77.4  270  38 19  -2.3  -1.3
 38000 -58.9 -74.0  260  34 18   5.0   2.7 | -59.2 -74.6  275  39 20   4.9   2.7
 36000 -55.9 -68.6  260  37 19   5.0   2.7 | -56.2 -69.2  285  40 21   4.9   2.7
 34000 -52.5 -62.5  265  38 20   7.6   4.2 | -52.5 -62.5  290  41 21   8.3   4.5
 32000 -47.3 -53.1  270  38 19   7.6   4.2 | -47.6 -53.7  290  41 21   8.2   4.5
 30000 -42.5 -44.5  275  37 19   8.3   4.6 | -42.6 -44.7  285  39 20   8.5   4.6
 29000 -40.0 -40.0  280  35 18   8.3   4.6 | -40.1 -40.2  285  37 19   8.5   4.6
 28000 -37.5 -35.5  280  34 17   8.3   4.6 | -37.6 -35.7  285  35 18   8.5   4.6
 27000 -35.0 -31.0  285  33 17   8.7   4.7 | -35.1 -31.2  285  34 17   8.2   4.5
 26000 -32.4 -26.3  290  33 17   8.6   4.7 | -32.0 -25.6  285  33 17   8.2   4.5
 25000 -29.8 -21.6  290  33 17   8.7   4.7 | -29.5 -21.1  285  33 17   8.2   4.5
 24000 -27.4 -17.3  295  33 17   6.2   3.4 | -27.1 -16.8  285  32 17   8.1   4.4
 23000 -25.5 -13.9  290  30 16   6.5   3.5 | -24.7 -12.5  285  32 16   8.1   4.4
 22000 -23.6 -10.5  285  28 14   6.5   3.6 | -22.3  -8.1  285  31 16   8.0   4.4
 21000 -21.5  -6.7  280  26 14   7.4   4.0 | -20.2  -4.4  285  29 15   5.9   3.2
 20000 -19.4  -2.9  275  25 13   7.4   4.0 | -18.5  -1.3  275  25 13   5.8   3.2
 19500 -18.3  -0.9  270  25 13   7.4   4.0 | -17.6   0.3  270  24 12   5.9   3.2
 19000 -17.2   1.0  270  25 13   7.3   4.0 | -16.8   1.8  265  23 12   6.1   3.4
 18500 -16.0   3.2  265  24 13   7.9   4.3 | -15.8   3.6  265  23 12   7.3   4.0
 18000 -14.9   5.2  265  24 12   7.8   4.3 | -14.7   5.5  260  24 12   7.2   3.9
 17500 -13.7   7.3  265  24 12   8.1   4.4 | -13.6   7.5  260  24 13   8.0   4.4
 17000 -12.5   9.5  265  23 12   8.2   4.5 | -12.4   9.7  260  24 12   8.2   4.5
 16500 -11.3  11.7  265  23 12   8.4   4.6 | -11.3  11.7  260  23 12   8.4   4.6
 16000 -10.0  14.0  265  22 12   9.1   5.0 | -10.0  14.0  260  22 12   8.8   4.8
 15500  -8.0  17.6  270  22 11   9.1   5.0 |  -8.7  16.3  260  22 11   8.8   4.8
 15000  -6.7  19.9  270  22 11   9.2   5.0 |  -7.4  18.7  265  22 11   9.3   5.1
 14500  -5.3  22.5  270  22 11   9.1   5.0 |  -6.0  21.2  265  22 11   9.2   5.1
 14000  -4.0  24.8  270  21 11   9.1   5.0 |  -4.6  23.7  270  22 11   9.5   5.2
 13500  -2.6  27.3  270  20 10   9.1   5.0 |  -3.2  26.2  270  21 11   9.5   5.2
 13000  -1.3  29.7  265  20 10   8.9   4.9 |  -1.1  30.0  270  21 11   9.5   5.2
 12500  -0.0  32.0  265  19 10   8.9   4.9 |   0.4  32.7  270  22 11   9.5   5.2
 12000   1.3  34.3  265  19 10   9.2   5.0 |   1.7  35.1  270  22 12   9.1   5.0
 11500   2.7  36.9  260  19 10   9.2   5.1 |   3.1  37.6  270  22 12   9.2   5.0
 11000   4.0  39.2  260  20 10   8.4   4.6 |   4.4  39.9  270  22 11   8.6   4.7
 10500   5.4  41.7  255  20 10   8.3   4.6 |   5.7  42.3  265  22 11   6.3   3.5
 10250   5.9  42.6  255  20 10   5.4   3.0 |   6.1  43.0  265  22 11   6.7   3.6
 10000   6.3  43.3  255  20 10   6.9   3.8 |   6.7  44.1  265  21 11  10.0   5.5
  9750   7.0  44.6  250  20 10   9.8   5.4 |   7.4  45.3  265  21 11   9.3   5.1
  9500   7.7  45.9  250  20 10   9.0   5.0 |   8.1  46.6  260  20 10   8.7   4.8
  9250   8.3  46.9  250  20 10   6.4   3.5 |   8.7  47.7  260  19 10   5.9   3.2
  9000   8.7  47.7  250  19 10   5.4   2.9 |   9.1  48.4  260  17  9   5.8   3.2
  8750   9.2  48.6  245  17  9   6.9   3.8 |   9.6  49.3  255  15  8   6.8   3.7
  8500   9.7  49.5  245  15  8   6.2   3.4 |  10.0  50.0  255  13  7   6.7   3.7
  8250  10.1  50.2  245  14  7   5.4   2.9 |  10.5  50.9  255  11  6   6.8   3.7
  8000  10.5  50.9  240  11  6   5.0   2.7 |  11.0  51.8  255   9  5   7.8   4.3
  7750  10.8  51.4  235  10  5   5.4   3.0 |  11.7  53.1  255   9  4   8.3   4.6
  7500  11.2  52.2  225   9  5   4.5   2.5 |  12.3  54.1  255   8  4   9.1   5.0
  7250  11.5  52.7  210   9  5   3.5   1.9 |  13.0  55.4  255   8  4  10.2   5.6
  7000  11.7  53.1  200  10  5   3.4   1.8 |  13.8  56.8  255   8  4  10.0   5.5
  6750  12.0  53.6  190  10  5   3.1   1.7 |  14.5  58.1  255   8  4  10.5   5.7
  6500  12.2  54.0  180  10  5   3.4   1.9 |  15.3  59.5  255   8  4  10.8   5.9
  6250  12.4  54.3  175   9  5   4.1   2.2 |  16.1  61.0  255   7  4  11.2   6.2
  6000  12.7  54.9  170   8  4   2.9   1.6 |  17.0  62.6  255   7  4  10.0   5.5
  5750  12.9  55.2  165   7  3   6.1   3.3 |  17.7  63.9  255   7  4  12.5   6.9
  5500  13.6  56.5  165   6  3  10.8   5.9 |  18.8  65.8  260   7  4  16.5   9.1
  5250  14.3  57.7  160   6  3   8.4   4.6 |  20.0  68.0  260   7  4  14.1   7.8
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/23/2018 at 1500 MDT          |       04/23/2018 at 1800 MDT
                                           |
K index... +12.3  LI... +0.8               | K index... +15.8  LI... +0.5
CAPE... 0.0  CIN... 0.0                    | CAPE... +1.8  CIN... -2.0
                                           |
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 -58.3 -72.9  265  29 15   0.8   0.4 | -58.4 -73.1  270  30 15   0.8   0.4
 45000 -57.4 -71.3  270  37 19  -3.0  -1.6 | -57.5 -71.5  280  39 20  -3.0  -1.6
 40000 -61.8 -79.2  280  48 25  -2.6  -1.4 | -61.4 -78.5  285  55 28  -2.6  -1.4
 38000 -59.7 -75.5  285  50 26   6.0   3.3 | -59.5 -75.1  285  58 30   6.2   3.4
 36000 -56.1 -69.0  285  50 26   6.0   3.3 | -55.7 -68.3  285  59 30   6.2   3.4
 34000 -52.0 -61.6  285  50 26   8.1   4.5 | -51.1 -60.0  280  58 30   7.9   4.4
 32000 -47.1 -52.8  280  50 26   8.1   4.4 | -46.3 -51.3  280  54 28   7.9   4.4
 30000 -42.3 -44.1  280  48 25   8.0   4.4 | -41.6 -42.9  280  51 26   7.5   4.1
 29000 -39.9 -39.8  275  47 24   8.0   4.4 | -39.3 -38.7  275  49 25   7.6   4.1
 28000 -37.5 -35.5  275  45 23   8.0   4.4 | -37.1 -34.8  270  47 24   7.6   4.1
 27000 -35.1 -31.2  275  44 22   8.3   4.6 | -34.8 -30.6  270  46 24   7.6   4.2
 26000 -32.0 -25.6  275  42 21   8.3   4.5 | -32.5 -26.5  270  44 22   7.6   4.2
 25000 -29.5 -21.1  275  40 21   8.3   4.5 | -30.2 -22.4  265  42 21   7.6   4.2
 24000 -27.1 -16.8  275  38 20   7.9   4.3 | -27.9 -18.2  265  40 20   8.2   4.5
 23000 -24.7 -12.5  275  37 19   7.9   4.3 | -25.4 -13.7  270  37 19   8.1   4.5
 22000 -22.3  -8.1  275  35 18   7.9   4.3 | -23.0  -9.4  270  35 18   8.1   4.5
 21000 -20.1  -4.2  275  33 17   7.1   3.9 | -20.6  -5.1  270  33 17   7.5   4.1
 20000 -18.0  -0.4  275  32 16   7.1   3.9 | -18.3  -0.9  270  32 16   7.5   4.1
 19500 -16.9   1.6  275  31 16   7.1   3.9 | -17.2   1.0  270  31 16   7.5   4.1
 19000 -15.9   3.4  275  30 16   7.3   4.0 | -16.1   3.0  270  30 16   7.6   4.2
 18500 -14.7   5.5  275  30 15   7.9   4.4 | -14.9   5.2  270  30 15   8.1   4.5
 18000 -13.6   7.5  270  29 15   8.0   4.4 | -13.7   7.3  270  29 15   8.1   4.5
 17500 -12.4   9.7  270  29 15   7.4   4.1 | -12.5   9.5  270  28 14   8.3   4.6
 17000 -11.4  11.5  270  28 15   7.4   4.0 | -11.3  11.7  270  27 14   8.4   4.6
 16500 -10.3  13.5  265  28 15   7.8   4.3 | -10.1  13.8  270  27 14   8.6   4.7
 16000  -9.1  15.6  265  28 15   8.5   4.7 |  -8.8  16.2  270  26 13   9.1   5.0
 15500  -7.8  18.0  265  28 14   8.6   4.7 |  -6.8  19.8  270  26 13   8.9   4.9
 15000  -6.5  20.3  265  28 14   8.7   4.8 |  -5.5  22.1  270  25 13   8.7   4.8
 14500  -5.3  22.5  260  28 14   8.6   4.7 |  -4.2  24.4  270  25 13   8.9   4.9
 14000  -4.0  24.8  260  27 14   9.1   5.0 |  -2.8  27.0  270  25 13   9.6   5.3
 13500  -2.6  27.3  260  27 14   9.2   5.0 |  -1.4  29.5  270  24 13   9.5   5.2
 13000  -0.6  30.9  260  26 13   9.0   4.9 |  -0.0  32.0  270  24 12   8.9   4.9
 12500   0.7  33.3  260  26 13   9.0   4.9 |   1.3  34.3  270  24 12   9.0   4.9
 12000   2.1  35.8  260  25 13   9.4   5.2 |   2.7  36.9  270  24 12   9.2   5.1
 11500   3.5  38.3  260  25 13   9.4   5.1 |   4.0  39.2  270  24 12   9.4   5.1
 11000   4.8  40.6  260  23 12   8.8   4.8 |   5.3  41.5  270  23 12   8.0   4.4
 10500   6.2  43.2  265  22 11   5.7   3.1 |   6.5  43.7  270  23 12  10.6   5.8
 10250   6.5  43.7  265  21 11   6.6   3.6 |   7.4  45.3  270  23 12  11.3   6.2
 10000   7.2  45.0  265  20 10  11.5   6.3 |   8.1  46.6  270  22 11   8.6   4.7
  9750   8.0  46.4  265  20 10  10.3   5.7 |   8.8  47.8  270  22 11   9.3   5.1
  9500   8.8  47.8  265  19 10  10.3   5.6 |   9.5  49.1  270  21 11   8.9   4.9
  9250   9.5  49.1  260  18  9   9.4   5.1 |  10.1  50.2  270  21 11   7.9   4.3
  9000  10.2  50.4  260  18  9  10.0   5.5 |  10.7  51.3  270  20 10   8.6   4.7
  8750  11.0  51.8  260  18  9  10.6   5.8 |  11.4  52.5  270  19 10   9.8   5.4
  8500  11.8  53.2  260  17  9  10.3   5.7 |  12.1  53.8  270  18  9   9.4   5.2
  8250  12.5  54.5  260  17  9  10.1   5.5 |  12.8  55.0  270  18  9   9.4   5.2
  8000  13.3  55.9  260  17  9  10.2   5.6 |  13.5  56.3  270  17  9   9.2   5.1
  7750  14.1  57.4  260  17  9  10.4   5.7 |  14.2  57.6  270  17  9   9.0   4.9
  7500  14.8  58.6  260  17  9  10.2   5.6 |  14.9  58.8  270  17  9   9.6   5.3
  7250  15.6  60.1  260  16  8  10.0   5.5 |  15.7  60.3  270  17  9  10.6   5.8
  7000  16.3  61.3  260  16  8  10.0   5.5 |  16.4  61.5  270  16  8  10.2   5.6
  6750  17.1  62.8  260  16  8  10.2   5.6 |  17.2  63.0  270  16  8   9.6   5.2
  6500  17.8  64.0  260  16  8  10.7   5.9 |  17.9  64.2  270  16  8  10.3   5.7
  6250  18.7  65.7  260  15  8  11.4   6.3 |  18.7  65.7  270  15  8  11.0   6.1
  6000  19.5  67.1  260  15  8  10.0   5.5 |  19.5  67.1  270  15  8  10.6   5.8
  5750  20.2  68.4  260  14  7  12.2   6.7 |  20.3  68.5  270  14  7  10.1   5.5
  5500  21.4  70.5  265  14  7  16.9   9.3 |  21.0  69.8  275  13  7   9.8   5.4
  5250  22.6  72.7  265  14  7  15.6   8.6 |  21.8  71.2  275  13  7  10.1   5.5
  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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