Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 211305
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0705 MDT Thursday, September 21, 2017

This forecast is for Thursday, September 21, 2017:

If the trigger temperature of 73.8 F/23.2 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 748 ft/min (3.8 m/s)
   Maximum height of thermals.................. 13980 ft MSL (9141 ft AGL)

Forecast maximum temperature................... 82.0 F/28.2 C
Time of trigger temperature.................... 1015 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ More than 30 mph
Height of the -3 thermal index................. 11729 ft MSL (6890 ft AGL)
Thermal soaring outlook for Friday 09/22....... Good

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

Remarks...

Sunrise/Sunset.................... 07:01:11 / 19:13:47 MDT
Total possible sunshine........... 12 hr 12 min 37 sec (732 min 37 sec)
Altitude of sun at 13:07:00 MDT... 51.29 degrees

Upper air data from rawinsonde observation taken on 09/21/2017 at 0600 MDT

Freezing level.................. 14158 ft MSL (9319 ft AGL)
Convective condensation level... 17147 ft MSL (12308 ft AGL)
Lifted condensation level....... 16527 ft MSL (11688 ft AGL)
Lifted index.................... +4.3
K index......................... +2.2

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  -63.6 -82.5   260   54   28   4.5   2.5   90.9 195.6    36.3      M    M
 45000  -60.4 -76.7   235   43   22   3.7   2.0   70.5 158.8    26.4      M    M
 40000  -53.3 -63.9   240   43   22  -3.8  -2.1   58.7 137.7    20.5      M    M
 38000  -52.7 -62.9   245   55   28   9.2   5.0   50.8 123.4    15.7      M    M
 36000  -47.5 -53.5   250   59   31   8.6   4.7   49.8 121.6    15.4      M    M
 34000  -42.6 -44.7   250   52   27   8.0   4.4   48.6 119.4    14.9      M    M
 32000  -37.3 -35.1   240   55   28   2.9   1.6   46.7 116.1    14.0      M    M
 30000  -34.7 -30.5   240   54   28   5.2   2.9   42.4 108.4    11.1      M    M
 29000  -33.0 -27.4   240   55   28   6.7   3.7   40.8 105.4     9.9      M    M
 28000  -30.3 -22.5   240   56   29   9.7   5.3   40.4 104.7     9.7      M    M
 27000  -27.4 -17.3   240   57   29   9.6   5.3   40.3 104.6     9.8      M    M
 26000  -24.5 -12.1   240   58   30   9.6   5.3   40.3 104.6     9.9      M    M
 25000  -21.7  -7.1   240   59   30   9.6   5.3   40.5 104.9    10.1      M    M
 24000  -18.8  -1.8   240   59   31   9.2   5.0   40.3 104.5    10.1      M    M
 23000  -16.0   3.2   235   58   30   9.2   5.1   40.0 104.0    10.0      M    M
 22000  -13.3   8.1   230   56   29   9.3   5.1   39.8 103.7    10.0      M    M
 21000  -10.9  12.4   230   55   28   2.4   1.3   39.3 102.7     9.6      M    M
 20000  -11.8  10.8   225   54   28   4.6   2.5   34.7  94.4     5.8      M    M
 19500  -11.2  11.8   230   53   28   3.9   2.1   33.7  92.6     5.0      M    M
 19000  -10.7  12.7   235   53   27   4.0   2.2   32.6  90.6     4.1      M    M
 18500  -10.4  13.3   235   53   27   3.8   2.1   31.4  88.4     2.9      M    M
 18000   -9.5  14.9   235   53   27   6.0   3.3   30.7  87.3     2.4      M    M
 17500   -8.0  17.6   235   52   27   9.0   5.0   30.0  86.0     1.8      M    M
 17000   -6.6  20.1   235   52   27   8.9   4.9   29.9  85.8     1.7      M    M
 16500   -5.6  21.9   235   52   27   5.5   3.0   29.3  84.8     1.2      M    M
 16000   -4.5  23.9   235   52   27   8.6   4.7   29.0  84.2     0.9      M    M
 15500   -3.2  26.2   240   52   27   8.5   4.7   28.8  83.8     0.7      M    M
 15000   -2.0  28.4   245   52   27   8.5   4.7   28.6  83.4     0.5      M    M
 14500   -0.7  30.7   240   51   26   8.7   4.8   28.3  83.0     0.3      M    M
 14000    0.4  32.7   240   50   26   5.5   3.0   28.0  82.4    -0.0    744  3.8
 13500    1.1  34.0   240   46   24   4.9   2.7   27.2  81.0    -0.8    708  3.6
 13000    2.1  35.8   240   42   22   8.3   4.5   26.7  80.0    -1.3    666  3.4
 12500    3.3  37.9   240   38   20   8.4   4.6   26.4  79.6    -1.6    614  3.1
 12000    4.3  39.7   240   35   18   0.3   0.2   26.0  78.8    -2.1    570  2.9
 11500    4.8  40.6   235   31   16  11.3   6.2   25.1  77.2    -3.0    539  2.7
 11000    6.3  43.3   225   28   15   4.5   2.5   25.2  77.3    -2.9    478  2.4
 10500    6.7  44.1   215   26   13   9.4   5.1   24.1  75.4    -4.1    453  2.3
 10250    7.4  45.3   210   25   13  10.5   5.7   24.1  75.5    -4.1    423  2.2
 10000    8.2  46.8   205   22   11   9.3   5.1   24.2  75.5    -4.1    394  2.0
  9750    8.8  47.8   200   22   11   8.8   4.8   24.1  75.4    -4.1    367  1.9
  9500    9.5  49.1   200   22   11   9.0   4.9   24.1  75.3    -4.2    340  1.7
  9250   10.1  50.2   195   22   11   8.9   4.9   24.0  75.2    -4.3    312  1.6
  9000   10.8  51.4   190   22   11   8.9   4.9   24.0  75.1    -4.3    285  1.4
  8750   11.5  52.7   185   22   11   8.9   4.9   23.9  75.0    -4.4    258  1.3
  8500   12.1  53.8   185   23   12   8.9   4.9   23.8  74.9    -4.5    231  1.2
  8250   12.8  55.0   180   23   12   8.9   4.9   23.8  74.8    -4.6    204  1.0
  8000   13.4  56.1   175   24   12   8.9   4.9   23.7  74.7    -4.6    177  0.9
  7750   14.1  57.4   175   24   12   8.9   4.9   23.7  74.6    -4.7    149  0.8
  7500   14.8  58.6   170   23   12   8.9   4.9   23.6  74.5    -4.8    122  0.6
  7250   15.4  59.7   170   23   12   8.9   4.9   23.5  74.4    -4.9     95  0.5
  7000   16.1  61.0   165   22   11   8.9   4.9   23.5  74.3    -5.0     68  0.3
  6750   16.7  62.1   165   23   12   9.0   4.9   23.4  74.1    -5.1     41  0.2
  6500   17.4  63.3   165   24   12   8.9   4.9   23.3  74.0    -5.1     14  0.1
  6250   18.1  64.6   160   25   13   9.0   5.0   23.3  73.9    -5.2      M    M
  6000   18.7  65.7   160   27   14   8.6   4.7   23.2  73.8    -5.3      M    M
  5750   19.4  66.9   160   24   12  10.2   5.6   23.1  73.7    -5.4      M    M
  5500   20.0  68.0   155   19   10   4.4   2.4   23.1  73.5    -5.5      M    M
  5250   20.0  68.0   150   15    8   0.3   0.2   22.4  72.3    -6.3      M    M
  5000   20.4  68.7   145   11    6  10.6   5.8   22.0  71.6    -6.6      M    M

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

           09/21/2017 at 0900 MDT          |       09/21/2017 at 1200 MDT
                                           |
K index... +5.3  LI... +1.5                | K index... +10.2  LI... +1.6
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 -64.3 -83.7  245  50 26   2.0   1.1 | -64.4 -83.9  240  52 27   2.0   1.1
 45000 -60.5 -76.9  245  56 29   4.3   2.3 | -60.5 -76.9  245  58 30   4.6   2.5
 40000 -54.1 -65.4  245  50 26   5.2   2.8 | -53.6 -64.5  245  56 29   5.3   2.9
 38000 -50.4 -58.7  245  52 27   6.1   3.3 | -50.0 -58.0  240  55 28   5.9   3.2
 36000 -46.8 -52.2  245  53 28   6.1   3.3 | -46.5 -51.7  235  54 28   5.9   3.2
 34000 -42.8 -45.0  245  56 29   7.0   3.8 | -42.7 -44.9  235  55 28   6.6   3.6
 32000 -38.7 -37.7  245  58 30   7.0   3.8 | -38.7 -37.7  235  57 29   6.6   3.6
 30000 -34.1 -29.4  240  58 30   6.6   3.6 | -34.0 -29.2  235  58 30   7.4   4.0
 29000 -32.2 -26.0  240  57 29   6.6   3.6 | -31.8 -25.2  235  58 30   7.4   4.0
 28000 -30.2 -22.4  235  57 29   6.4   3.5 | -29.6 -21.3  235  58 30   7.3   4.0
 27000 -27.6 -17.7  235  54 28   9.4   5.2 | -27.1 -16.8  235  56 29   8.6   4.7
 26000 -24.8 -12.6  230  51 26   9.5   5.2 | -24.6 -12.3  230  52 27   8.6   4.7
 25000 -22.0  -7.6  230  47 24   9.4   5.2 | -22.0  -7.6  225  49 25   8.6   4.7
 24000 -19.3  -2.7  230  46 24   8.1   4.4 | -19.4  -2.9  225  48 25   8.3   4.6
 23000 -16.9   1.6  230  49 25   8.1   4.4 | -16.9   1.6  225  51 26   8.3   4.6
 22000 -14.5   5.9  235  52 27   7.9   4.4 | -14.4   6.1  230  54 28   8.2   4.5
 21000 -12.6   9.3  235  53 27   4.5   2.5 | -12.5   9.5  230  55 28   4.1   2.3
 20000 -11.2  11.8  235  52 27   4.4   2.4 | -11.4  11.5  230  53 27   4.1   2.2
 19500 -10.6  12.9  235  51 26   4.4   2.4 | -10.8  12.6  230  53 27   4.1   2.2
 19000  -9.9  14.2  235  51 26   4.4   2.4 | -10.2  13.6  230  52 27   4.1   2.2
 18500  -9.2  15.4  235  50 26   5.4   2.9 |  -9.5  14.9  230  52 27   4.9   2.7
 18000  -8.4  16.9  235  49 25   5.3   2.9 |  -8.8  16.2  230  51 26   4.9   2.7
 17500  -7.6  18.3  235  49 25   6.0   3.3 |  -8.1  17.4  230  50 26   5.8   3.2
 17000  -6.7  19.9  235  48 25   6.3   3.5 |  -7.1  19.2  230  49 25   6.4   3.5
 16500  -5.7  21.7  235  48 24   6.4   3.5 |  -6.2  20.8  230  49 25   6.5   3.6
 16000  -4.8  23.4  235  47 24   6.3   3.4 |  -5.2  22.6  230  48 25   6.9   3.8
 15500  -3.9  25.0  235  46 24   6.3   3.4 |  -4.2  24.4  230  47 24   6.8   3.7
 15000  -2.9  26.8  235  44 23   6.6   3.6 |  -3.1  26.4  230  45 23   7.2   4.0
 14500  -1.5  29.3  235  42 22   6.6   3.6 |  -1.5  29.3  230  42 22   7.3   4.0
 14000  -0.5  31.1  230  39 20   6.9   3.8 |  -0.5  31.1  225  39 20   7.3   4.0
 13500   0.5  32.9  230  37 19   6.9   3.8 |   0.6  33.1  225  36 19   7.5   4.1
 13000   1.4  34.5  230  33 17   6.6   3.6 |   1.6  34.9  220  34 17   6.3   3.4
 12500   2.3  36.1  225  30 15   6.6   3.6 |   2.4  36.3  220  31 16   6.3   3.5
 12000   3.3  37.9  225  27 14   7.4   4.1 |   3.4  38.1  220  30 15   7.9   4.3
 11500   4.3  39.7  225  27 14   7.5   4.1 |   4.5  40.1  220  29 15   8.1   4.5
 11000   5.4  41.7  230  27 14   7.6   4.2 |   5.7  42.3  220  28 14   7.8   4.3
 10500   6.5  43.7  230  28 15   7.7   4.2 |   6.8  44.2  215  26 13   7.8   4.3
 10250   7.0  44.6  230  29 15   8.9   4.9 |   7.3  45.1  215  25 13   8.7   4.8
 10000   7.7  45.9  230  30 15   9.1   5.0 |   8.0  46.4  215  25 13  10.0   5.5
  9750   8.3  46.9  230  30 15   8.6   4.7 |   8.7  47.7  215  24 13  10.2   5.6
  9500   8.9  48.0  230  30 16   8.4   4.6 |   9.5  49.1  215  24 12  10.3   5.6
  9250   9.5  49.1  225  31 16   9.9   5.4 |  10.3  50.5  215  24 12   9.7   5.3
  9000  10.3  50.5  225  31 16   9.4   5.2 |  11.0  51.8  215  24 12   9.5   5.2
  8750  10.8  51.4  225  31 16   7.5   4.1 |  11.7  53.1  215  24 12  10.1   5.5
  8500  11.4  52.5  225  31 16   8.0   4.4 |  12.4  54.3  215  23 12   9.6   5.3
  8250  12.0  53.6  220  31 16   7.8   4.3 |  13.2  55.8  215  23 12  10.8   5.9
  8000  12.5  54.5  220  31 16   6.5   3.6 |  14.0  57.2  215  23 12  10.6   5.8
  7750  13.0  55.4  215  31 16   5.6   3.1 |  14.7  58.5  215  23 12   9.3   5.1
  7500  13.4  56.1  210  31 16   5.7   3.2 |  15.4  59.7  215  23 12   9.6   5.3
  7250  13.8  56.8  205  31 16   2.1   1.2 |  16.2  61.2  215  22 11  10.4   5.7
  7000  13.8  56.8  200  28 14  -0.7  -0.4 |  17.0  62.6  215  22 11  10.5   5.8
  6750  13.8  56.8  195  25 13  -1.3  -0.7 |  17.7  63.9  215  22 11   9.6   5.3
  6500  13.7  56.7  185  22 11   0.5   0.3 |  18.5  65.3  215  21 11  10.2   5.6
  6250  14.0  57.2  180  20 10   4.2   2.3 |  19.3  66.7  215  20 11  11.3   6.2
  6000  14.3  57.7  175  17  9   5.3   2.9 |  20.1  68.2  215  20 10  11.8   6.5
  5750  14.8  58.6  175  15  8   7.0   3.8 |  21.0  69.8  215  19 10  11.7   6.4
  5500  15.4  59.7  170  13  7   8.2   4.5 |  21.9  71.4  215  17  9  13.6   7.5
  5250  16.0  60.8  170  12  6   7.8   4.3 |  23.1  73.6  215  17  9  17.2   9.5
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           09/21/2017 at 1500 MDT          |       09/21/2017 at 1800 MDT
                                           |
K index... +15.0  LI... +2.0               | K index... +15.3  LI... +2.9
CAPE... +0.1  CIN... -0.1                  | 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 -64.6 -84.3  240  52 27   2.2   1.2 | -64.5 -84.1  240  55 28   2.8   1.5
 45000 -60.2 -76.4  245  69 35   5.1   2.8 | -59.6 -75.3  245  84 43   4.3   2.4
 40000 -52.5 -62.5  245  62 32   5.1   2.8 | -53.1 -63.6  240  84 43   4.4   2.4
 38000 -49.5 -57.1  245  63 33   5.0   2.7 | -50.4 -58.7  240  79 41   4.5   2.5
 36000 -46.5 -51.7  240  65 33   5.0   2.7 | -47.7 -53.9  235  75 38   4.5   2.5
 34000 -43.0 -45.4  235  66 34   6.5   3.6 | -44.0 -47.2  235  71 37   7.7   4.3
 32000 -39.1 -38.4  235  66 34   6.5   3.6 | -39.3 -38.7  230  69 36   7.8   4.3
 30000 -33.9 -29.0  230  65 33   8.5   4.6 | -33.9 -29.0  225  66 34   8.3   4.6
 29000 -31.4 -24.5  230  64 33   8.5   4.6 | -31.4 -24.5  225  64 33   8.3   4.6
 28000 -28.8 -19.8  230  63 32   8.5   4.7 | -28.9 -20.0  225  63 32   8.4   4.6
 27000 -26.4 -15.5  230  61 32   8.0   4.4 | -26.7 -16.1  225  62 32   7.1   3.9
 26000 -24.0 -11.2  230  59 31   8.0   4.4 | -24.5 -12.1  225  62 32   7.1   3.9
 25000 -21.6  -6.9  225  58 30   8.0   4.4 | -22.4  -8.3  225  62 32   7.1   3.9
 24000 -19.3  -2.7  225  57 29   7.1   3.9 | -20.2  -4.4  225  61 32   8.1   4.5
 23000 -17.2   1.0  225  56 29   7.1   3.9 | -17.8  -0.0  225  60 31   8.1   4.4
 22000 -15.0   5.0  225  55 28   7.1   3.9 | -15.3   4.5  225  60 31   8.0   4.4
 21000 -13.2   8.2  225  54 28   5.3   2.9 | -13.3   8.1  225  58 30   5.2   2.8
 20000 -11.6  11.1  225  53 27   5.3   2.9 | -11.7  10.9  225  56 29   5.2   2.9
 19500 -10.9  12.4  225  52 27   5.3   2.9 | -11.0  12.2  225  55 28   5.2   2.9
 19000 -10.1  13.8  225  52 27   5.3   2.9 | -10.2  13.6  225  53 27   5.3   2.9
 18500  -9.3  15.3  225  51 26   5.5   3.0 |  -9.5  14.9  220  52 27   5.1   2.8
 18000  -8.5  16.7  225  50 26   5.5   3.0 |  -8.7  16.3  220  51 26   5.2   2.9
 17500  -7.7  18.1  225  49 25   5.5   3.0 |  -8.0  17.6  220  50 26   5.9   3.2
 17000  -6.9  19.6  225  48 25   5.5   3.0 |  -7.1  19.2  220  48 25   6.4   3.5
 16500  -6.1  21.0  220  47 24   5.6   3.1 |  -6.2  20.8  220  46 23   6.5   3.6
 16000  -5.1  22.8  220  46 23   7.1   3.9 |  -5.1  22.8  220  44 23   7.9   4.4
 15500  -4.1  24.6  220  44 23   6.9   3.8 |  -4.0  24.8  220  42 22   7.8   4.3
 15000  -3.1  26.4  220  43 22   7.8   4.3 |  -2.8  27.0  220  41 21   8.2   4.5
 14500  -1.4  29.5  215  40 21   8.0   4.4 |  -0.9  30.4  220  40 21   8.2   4.5
 14000  -0.2  31.6  215  38 20   8.4   4.6 |   0.3  32.5  215  40 20   8.6   4.7
 13500   1.1  34.0  215  36 19   8.4   4.6 |   1.6  34.9  215  40 20   8.6   4.7
 13000   2.3  36.1  215  34 18   9.0   4.9 |   2.9  37.2  210  39 20   8.6   4.7
 12500   3.7  38.7  215  32 17   9.0   5.0 |   4.1  39.4  210  38 19   8.6   4.7
 12000   5.0  41.0  215  30 16   8.8   4.8 |   5.4  41.7  205  36 19   9.4   5.2
 11500   6.3  43.3  210  28 14   8.8   4.8 |   6.9  44.4  205  36 19   9.7   5.3
 11000   7.5  45.5  210  26 14   9.0   5.0 |   8.3  46.9  205  36 18   9.6   5.3
 10500   8.9  48.0  205  26 13   9.4   5.1 |   9.8  49.6  205  35 18   9.8   5.4
 10250   9.6  49.3  205  25 13  10.2   5.6 |  10.5  50.9  205  35 18  10.4   5.7
 10000  10.4  50.7  205  25 13  10.3   5.6 |  11.3  52.3  205  34 18  10.2   5.6
  9750  11.1  52.0  205  25 13  10.1   5.5 |  12.0  53.6  205  34 17   9.7   5.3
  9500  11.9  53.4  205  25 13  10.4   5.7 |  12.8  55.0  205  34 17  10.4   5.7
  9250  12.6  54.7  205  25 13   9.4   5.1 |  13.5  56.3  200  33 17   8.2   4.5
  9000  13.3  55.9  205  25 13   9.2   5.0 |  14.1  57.4  200  33 17   8.3   4.5
  8750  14.1  57.4  205  24 13  10.2   5.6 |  14.8  58.6  200  32 17  10.5   5.8
  8500  14.8  58.6  205  24 12   9.6   5.3 |  15.6  60.1  200  32 16   9.6   5.3
  8250  15.5  59.9  205  24 12  11.1   6.1 |  16.3  61.3  200  31 16  11.0   6.0
  8000  16.4  61.5  205  24 12  10.7   5.9 |  17.2  63.0  200  31 16  10.2   5.6
  7750  17.1  62.8  205  23 12   9.1   5.0 |  17.8  64.0  200  30 16   8.5   4.7
  7500  17.8  64.0  205  23 12   9.3   5.1 |  18.5  65.3  200  30 15   8.8   4.8
  7250  18.5  65.3  205  23 12  10.1   5.6 |  19.1  66.4  200  29 15   9.4   5.1
  7000  19.3  66.7  205  23 12  10.7   5.9 |  19.9  67.8  200  28 15  10.0   5.5
  6750  20.1  68.2  205  22 12  10.1   5.5 |  20.6  69.1  195  27 14   9.7   5.3
  6500  20.9  69.6  205  22 11  10.3   5.6 |  21.4  70.5  195  26 14   9.7   5.3
  6250  21.6  70.9  205  22 11  10.7   5.9 |  22.1  71.8  195  25 13  10.0   5.5
  6000  22.5  72.5  205  21 11  11.4   6.2 |  22.8  73.0  195  24 12   9.9   5.4
  5750  23.3  73.9  205  20 10  11.2   6.2 |  23.5  74.3  195  22 11   9.8   5.4
  5500  24.2  75.6  200  18  9  13.1   7.2 |  24.2  75.6  195  18 10   8.3   4.5
  5250  25.3  77.5  205  18  9  17.3   9.5 |  24.7  76.5  195  17  9   4.3   2.4
  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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