Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 221231
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0631 MDT Saturday, April 22, 2017

This forecast is for Saturday, April 22, 2017:

If the trigger temperature of 50.1 F/10.1 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 743 ft/min (3.8 m/s)
   Maximum height of thermals.................. 15129 ft MSL (10290 ft AGL)

Forecast maximum temperature................... 68.0 F/20.5 C
Time of trigger temperature.................... 1015 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 14752 ft MSL (9913 ft AGL)
Thermal soaring outlook for Sunday 04/23....... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:27:09 / 19:57:44 MDT
Total possible sunshine........... 13 hr 30 min 35 sec (810 min 35 sec)
Altitude of sun at 13:12:37 MDT... 63.34 degrees

Upper air data from rawinsonde observation taken on 04/22/2017 at 0600 MDT

Freezing level.................. 7991 ft MSL (3152 ft AGL)
Convective condensation level... 13091 ft MSL (8252 ft AGL)
Lifted condensation level....... 15869 ft MSL (11030 ft AGL)
Lifted index.................... +8.2
K index......................... -4.4

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  -57.4 -71.3   310   41   21   4.2   2.3  106.2 223.1    49.0      M    M
 45000  -69.2 -92.6   310   52   27   7.4   4.1   60.9 141.6    25.0      M    M
 40000  -60.2 -76.4   305   79   41   2.9   1.6   52.1 125.8    21.0      M    M
 38000  -56.2 -69.2   305   85   44   8.1   4.5   48.1 118.5    19.0      M    M
 36000  -51.4 -60.5   305   90   46   7.8   4.3   46.7 116.1    18.5      M    M
 34000  -46.6 -51.9   300   86   44   9.0   4.9   45.2 113.4    18.0      M    M
 32000  -43.5 -46.3   300   78   40   7.6   4.2   41.4 106.6    15.6      M    M
 30000  -38.4 -37.1   300   75   39   8.7   4.8   40.4 104.6    15.2      M    M
 29000  -35.8 -32.4   300   72   37   6.5   3.5   39.9 103.9    15.1      M    M
 28000  -34.4 -29.9   300   68   35   6.9   3.8   37.9 100.1    13.7      M    M
 27000  -32.2 -26.0   300   65   34   9.1   5.0   36.9  98.5    13.2      M    M
 26000  -29.5 -21.1   300   65   34   8.2   4.5   36.6  97.8    13.0      M    M
 25000  -26.9 -16.4   300   66   34   9.2   5.1   36.2  97.1    12.9      M    M
 24000  -24.1 -11.4   305   66   34   8.9   4.9   36.0  96.8    12.9      M    M
 23000  -21.6  -6.9   310   66   34   8.4   4.6   35.3  95.6    12.5      M    M
 22000  -19.1  -2.4   310   65   34   8.4   4.6   34.8  94.7    12.2      M    M
 21000  -16.5   2.3   310   65   33   8.4   4.6   34.4  93.9    12.0      M    M
 20000  -13.4   7.9   315   65   34   8.4   4.6   34.0  93.2    11.8      M    M
 19500  -12.1  10.2   315   66   34   8.5   4.6   33.7  92.6    11.7      M    M
 19000  -10.9  12.4   315   66   34   9.3   5.1   33.4  92.2    11.5      M    M
 18500  -10.3  13.5   315   63   32  -2.3  -1.3   32.4  90.4    10.7      M    M
 18000  -10.7  12.7   310   59   30   2.6   1.4   30.2  86.4     8.9      M    M
 17500   -9.5  14.9   305   55   28   6.6   3.6   29.8  85.7     8.6      M    M
 17000   -8.4  16.9   305   51   26   1.1   0.6   29.4  85.0     8.3      M    M
 16500   -8.9  16.0   300   48   25   0.3   0.2   27.2  81.0     6.4      M    M
 16000   -9.3  15.3   295   44   22 -10.0  -5.5   25.2  77.3     4.6      M    M
 15500  -10.9  12.4   295   34   17  -5.8  -3.2   21.7  71.0     1.5      M    M
 15000  -12.0  10.4   295   24   12 -16.2  -8.9   18.8  65.8    -1.1    754  3.8
 14500  -14.9   5.2   300   14    7  -4.6  -2.5   14.2  57.5    -5.5    825  4.2
 14000  -13.9   7.0   315    5    3   9.1   5.0   13.7  56.6    -6.0    781  4.0
 13500  -12.6   9.3   325    4    2   9.1   5.0   13.6  56.4    -6.2    726  3.7
 13000  -11.2  11.8   340    3    2   9.1   5.0   13.4  56.2    -6.3    671  3.4
 12500   -9.9  14.2   360    3    2   9.1   5.0   13.4  56.0    -6.4    615  3.1
 12000   -8.5  16.7   020    3    2   9.0   4.9   13.3  55.9    -6.6    560  2.8
 11500   -7.2  19.0   015    3    2   7.5   4.1   13.2  55.7    -6.7    505  2.6
 11000   -6.4  20.5   010    3    2   5.5   3.0   12.5  54.5    -7.4    466  2.4
 10500   -5.6  21.9   005    3    2   5.9   3.2   11.8  53.2    -8.1    427  2.2
 10250   -5.1  22.8   360    3    2   8.3   4.6   11.6  52.8    -8.4    404  2.1
 10000   -4.4  24.1   010    3    2   8.1   4.5   11.5  52.7    -8.5    377  1.9
  9750   -3.9  25.0   020    3    2   6.9   3.8   11.3  52.3    -8.7    354  1.8
  9500   -3.3  26.1   030    4    2   7.2   4.0   11.1  51.9    -8.9    330  1.7
  9250   -2.8  27.0   040    4    2   7.1   3.9   10.9  51.6    -9.1    307  1.6
  9000   -2.3  27.9   045    5    3   7.2   3.9   10.7  51.3    -9.3    283  1.4
  8750   -1.7  28.9   050    7    3   7.1   3.9   10.5  50.9    -9.6    260  1.3
  8500   -1.2  29.8   055    9    4   7.2   3.9   10.3  50.5    -9.8    236  1.2
  8250   -0.7  30.7   060   11    5   7.1   3.9   10.1  50.1   -10.0    213  1.1
  8000   -0.1  31.8   060   13    7   7.2   4.0    9.9  49.8   -10.2    190  1.0
  7750    0.4  32.7   055   12    6   6.8   3.7    9.7  49.4   -10.5    166  0.8
  7500    1.0  33.8   045   11    6   8.4   4.6    9.5  49.0   -10.7    143  0.7
  7250    1.7  35.1   035   10    5  10.1   5.5    9.5  49.0   -10.7    114  0.6
  7000    2.4  36.3   025   10    5   9.8   5.4    9.5  49.1   -10.7     84  0.4
  6750    3.2  37.8   015    9    5   9.9   5.4    9.5  49.1   -10.8     54  0.3
  6500    3.9  39.0   010    8    4   9.9   5.4    9.5  49.1   -10.8     25  0.1
  6250    4.6  40.3   360    8    4   9.8   5.4    9.5  49.1   -10.8      M    M
  6000    5.4  41.7   350    7    4  10.3   5.6    9.5  49.1   -10.8      M    M
  5750    6.1  43.0   340    7    3   8.5   4.7    9.5  49.2   -10.8      M    M
  5500    6.7  44.1   335    6    3   6.4   3.5    9.3  48.8   -11.1      M    M
  5250    7.2  45.0   330    6    3   7.0   3.9    9.1  48.4   -11.3      M    M
  5000    7.7  45.9   320    6    3   5.7   3.1    8.9  48.0   -11.6      M    M

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

           04/22/2017 at 0900 MDT          |       04/22/2017 at 1200 MDT
                                           |
K index... -21.5  LI... +14.7              | K index... -33.7  LI... +13.3
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 -63.1 -81.6  305  33 17  -2.5  -1.4 | -63.5 -82.3  300  37 19  -2.3  -1.2
 45000 -66.5 -87.7  300  50 26   4.6   2.5 | -66.4 -87.5  295  52 27   4.5   2.5
 40000 -60.6 -77.1  305  75 39   4.0   2.2 | -60.7 -77.3  300  69 35   3.9   2.1
 38000 -56.2 -69.2  305  79 40   7.5   4.1 | -56.6 -69.9  305  67 34   6.9   3.8
 36000 -51.6 -60.9  305  79 41   7.5   4.1 | -52.4 -62.3  310  63 32   6.9   3.8
 34000 -47.2 -53.0  305  77 40   7.0   3.8 | -48.1 -54.6  315  62 32   7.4   4.1
 32000 -43.0 -45.4  305  72 37   7.0   3.8 | -43.7 -46.7  315  62 32   7.4   4.1
 30000 -38.8 -37.8  310  68 35   7.3   4.0 | -39.0 -38.2  315  60 31   8.0   4.4
 29000 -36.6 -33.9  310  66 34   7.3   4.0 | -36.6 -33.9  320  58 30   8.0   4.4
 28000 -34.4 -29.9  315  64 33   7.3   4.0 | -34.2 -29.6  320  55 28   8.0   4.4
 27000 -32.1 -25.8  315  63 33   8.6   4.7 | -31.8 -25.2  320  53 27   8.3   4.5
 26000 -29.5 -21.1  315  63 32   8.5   4.7 | -29.3 -20.7  320  52 27   8.3   4.5
 25000 -27.0 -16.6  315  62 32   8.5   4.7 | -26.8 -16.2  320  51 26   8.3   4.5
 24000 -24.4 -11.9  320  62 32   8.9   4.9 | -24.3 -11.7  320  50 26   8.7   4.8
 23000 -21.7  -7.1  320  62 32   9.0   4.9 | -21.7  -7.1  325  49 25   8.7   4.8
 22000 -19.0  -2.2  320  62 32   9.0   4.9 | -18.4  -1.1  330  49 25   8.7   4.8
 21000 -15.8   3.6  325  61 31   7.6   4.2 | -15.8   3.6  330  48 25   8.6   4.7
 20000 -13.5   7.7  325  58 30   7.6   4.2 | -13.2   8.2  330  47 24   8.6   4.7
 19500 -12.4   9.7  325  56 29   7.6   4.2 | -11.9  10.6  330  46 23   8.6   4.7
 19000 -11.3  11.7  325  54 28   7.8   4.3 | -10.6  12.9  330  45 23   7.8   4.3
 18500 -10.4  13.3  325  52 27   3.4   1.9 |  -9.9  14.2  330  42 22   2.7   1.5
 18000  -9.9  14.2  325  49 25   3.8   2.1 |  -9.5  14.9  325  40 20   3.0   1.6
 17500  -9.3  15.3  320  45 23   2.7   1.5 |  -9.0  15.8  325  37 19   3.7   2.1
 17000  -9.0  15.8  320  42 22   1.8   1.0 |  -8.4  16.9  325  35 18   3.8   2.1
 16500  -8.8  16.2  320  39 20   1.3   0.7 |  -7.8  18.0  325  33 17   2.5   1.4
 16000  -9.2  15.4  325  34 18  -5.5  -3.0 |  -7.8  18.0  335  29 15  -1.3  -0.7
 15500  -9.9  14.2  335  28 15  -4.9  -2.7 |  -8.0  17.6  340  25 13  -1.2  -0.7
 15000 -10.7  12.7  345  23 12  -5.1  -2.8 |  -8.2  17.2  355  21 11  -1.0  -0.5
 14500 -11.5  11.3  355  19 10  -5.1  -2.8 |  -8.4  16.9  010  18  9  -1.1  -0.6
 14000 -12.0  10.4  010  15  8   0.5   0.3 |  -8.4  16.9  025  16  8   1.1   0.6
 13500 -11.8  10.8  020  13  7   2.0   1.1 |  -8.2  17.2  040  15  8   1.2   0.7
 13000 -11.4  11.5  035  11  6   6.2   3.4 |  -8.0  17.6  055  14  7   3.4   1.9
 12500 -10.2  13.6  045  11  6   8.0   4.4 |  -7.4  18.7  065  13  7   3.9   2.1
 12000  -9.0  15.8  055  11  6   8.7   4.8 |  -6.7  19.9  075  13  6   6.0   3.3
 11500  -7.6  18.3  060  11  6   9.0   4.9 |  -5.8  21.6  075  12  6   6.6   3.6
 11000  -6.3  20.7  065  11  6   9.0   4.9 |  -4.8  23.4  080  11  6   7.0   3.9
 10500  -4.9  23.2  065  11  6   9.6   5.3 |  -3.8  25.2  075  10  5   7.9   4.3
 10250  -4.3  24.3  065  11  6   6.2   3.4 |  -3.2  26.2  070   9  5   4.1   2.3
 10000  -4.0  24.8  065  11  6   4.8   2.7 |  -3.0  26.6  070   9  4   5.0   2.7
  9750  -3.4  25.9  070  10  5   9.0   4.9 |  -2.4  27.7  065   8  4   9.9   5.5
  9500  -2.7  27.1  070  10  5  10.1   5.6 |  -1.7  28.9  065   8  4   9.7   5.3
  9250  -2.0  28.4  070  10  5   8.4   4.6 |  -1.1  30.0  060   7  4   8.3   4.6
  9000  -1.5  29.3  070  10  5   6.7   3.7 |  -0.5  31.1  060   7  3   7.5   4.1
  8750  -0.9  30.4  070  10  5   8.0   4.4 |   0.1  32.2  060   6  3   9.9   5.5
  8500  -0.3  31.5  070  11  5   8.6   4.7 |   0.9  33.6  055   6  3  10.5   5.8
  8250   0.3  32.5  065  11  6   6.5   3.5 |   1.6  34.9  055   6  3   9.5   5.2
  8000   0.7  33.3  065  12  6   5.2   2.9 |   2.3  36.1  055   6  3   9.1   5.0
  7750   1.0  33.8  060  13  7   5.3   2.9 |   3.0  37.4  055   6  3  10.2   5.6
  7500   1.4  34.5  060  14  7   5.0   2.7 |   3.8  38.8  055   6  3  10.5   5.7
  7250   1.7  35.1  060  14  7   5.2   2.9 |   4.5  40.1  055   5  3   9.9   5.4
  7000   2.1  35.8  055  13  7   5.0   2.7 |   5.2  41.4  055   5  3   9.7   5.3
  6750   2.5  36.5  055  12  6   5.8   3.2 |   6.0  42.8  055   5  3  10.5   5.7
  6500   3.0  37.4  050  11  6   6.9   3.8 |   6.8  44.2  055   5  3  11.0   6.0
  6250   3.5  38.3  050  10  5   7.5   4.1 |   7.6  45.7  055   5  2  11.4   6.2
  6000   4.0  39.2  050   9  5   5.8   3.2 |   8.5  47.3  055   5  2   9.5   5.2
  5750   4.5  40.1  050   8  4  12.0   6.6 |   9.3  48.7  055   4  2  16.6   9.1
  5500   6.0  42.8  050   8  4  26.4  14.5 |  11.2  52.2  050   4  2  34.4  18.9
  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

           04/22/2017 at 1500 MDT          |       04/22/2017 at 1800 MDT
                                           |
K index... -30.3  LI... +12.1              | K index... -39.0  LI... +10.7
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 -63.7 -82.7  290  43 22  -1.3  -0.7 | -64.2 -83.6  285  46 24  -1.7  -0.9
 45000 -65.5 -85.9  290  53 27   2.6   1.4 | -66.5 -87.7  285  53 27   2.2   1.2
 40000 -62.0 -79.6  300  62 32   2.0   1.1 | -63.4 -82.1  300  57 29   1.6   0.9
 38000 -58.2 -72.8  305  58 30   7.2   4.0 | -59.2 -74.6  300  54 28   8.1   4.4
 36000 -53.8 -64.8  310  54 28   7.2   4.0 | -54.3 -65.7  305  50 25   8.1   4.4
 34000 -49.2 -56.6  315  52 27   8.4   4.6 | -49.4 -56.9  310  47 24   8.4   4.6
 32000 -44.2 -47.6  320  54 28   8.4   4.6 | -44.4 -47.9  315  46 23   8.4   4.6
 30000 -39.1 -38.4  320  54 28   8.3   4.6 | -39.3 -38.7  315  44 23   8.6   4.7
 29000 -36.6 -33.9  325  53 27   8.4   4.6 | -36.7 -34.1  315  42 22   8.6   4.7
 28000 -33.5 -28.3  325  52 27   8.4   4.6 | -33.5 -28.3  315  41 21   8.6   4.7
 27000 -31.1 -24.0  325  50 26   7.9   4.3 | -30.8 -23.4  320  39 20   8.8   4.8
 26000 -28.8 -19.8  325  47 24   7.9   4.3 | -28.2 -18.8  325  38 20   8.8   4.8
 25000 -26.4 -15.5  320  43 22   8.0   4.4 | -25.6 -14.1  330  37 19   8.8   4.8
 24000 -24.0 -11.2  320  41 21   8.3   4.6 | -23.1  -9.6  330  35 18   7.7   4.2
 23000 -21.5  -6.7  325  38 20   8.3   4.6 | -20.8  -5.4  320  32 17   7.7   4.2
 22000 -19.0  -2.2  325  36 19   8.4   4.6 | -18.5  -1.3  315  30 15   7.8   4.3
 21000 -16.3   2.7  325  35 18   9.0   4.9 | -16.1   3.0  310  29 15   8.0   4.4
 20000 -13.6   7.5  325  35 18   9.0   4.9 | -13.7   7.3  310  28 14   8.0   4.4
 19500 -12.3   9.9  325  35 18   9.0   4.9 | -12.5   9.5  310  28 14   8.0   4.4
 19000 -10.9  12.4  325  35 18   8.9   4.9 | -11.3  11.7  310  27 14   8.1   4.4
 18500  -9.7  14.5  320  35 18   7.4   4.1 | -10.0  14.0  310  27 14   8.5   4.7
 18000  -8.6  16.5  320  35 18   7.6   4.2 |  -8.8  16.2  310  28 14   8.5   4.7
 17500  -7.5  18.5  320  35 18   5.7   3.1 |  -7.5  18.5  310  28 14   8.1   4.5
 17000  -6.8  19.8  320  34 17   4.8   2.6 |  -6.3  20.7  315  28 14   8.0   4.4
 16500  -6.1  21.0  320  33 17   4.4   2.4 |  -5.1  22.8  315  28 14   7.3   4.0
 16000  -5.7  21.7  325  30 15   1.8   1.0 |  -4.2  24.4  315  27 14   4.8   2.6
 15500  -5.4  22.3  325  26 14   2.3   1.3 |  -3.5  25.7  315  25 13   5.6   3.1
 15000  -5.3  22.5  335  22 11  -1.8  -1.0 |  -3.2  26.2  315  21 11  -1.9  -1.0
 14500  -5.6  21.9  345  17  9  -1.8  -1.0 |  -3.4  25.9  315  16  8  -1.6  -0.9
 14000  -5.8  21.6  005  13  7   0.7   0.4 |  -3.6  25.5  315  11  6   0.5   0.3
 13500  -5.4  22.3  035  11  6   1.4   0.8 |  -3.3  26.1  325   4  2   0.9   0.5
 13000  -4.9  23.2  055  11  6   5.7   3.1 |  -2.8  27.0  355   1  0   5.6   3.1
 12500  -4.1  24.6  070  11  6   5.2   2.9 |  -2.1  28.2  145   1  1   5.0   2.7
 12000  -3.3  26.1  080  10  5   5.6   3.1 |  -1.2  29.8  165   3  1   7.2   3.9
 11500  -2.5  27.5  090   8  4   5.8   3.2 |  -0.2  31.6  180   4  2   7.1   3.9
 11000  -1.7  28.9  090   6  3   5.6   3.1 |   0.9  33.6  180   5  3   7.1   3.9
 10500  -0.9  30.4  090   4  2   5.5   3.0 |   1.9  35.4  180   5  3   7.4   4.1
 10250  -0.6  30.9  090   3  2   4.0   2.2 |   2.3  36.1  180   5  3   4.2   2.3
 10000  -0.3  31.5  090   3  2   6.5   3.5 |   2.6  36.7  170   4  2   5.0   2.7
  9750   0.4  32.7  090   3  1   9.4   5.1 |   3.1  37.6  160   4  2   8.2   4.5
  9500   1.0  33.8  085   3  1   8.5   4.6 |   3.7  38.7  145   3  2   7.3   4.0
  9250   1.6  34.9  085   2  1   6.8   3.7 |   4.1  39.4  135   3  2   5.7   3.1
  9000   2.1  35.8  085   2  1   8.3   4.5 |   4.5  40.1  125   3  2   6.2   3.4
  8750   2.8  37.0  085   2  1  10.7   5.9 |   5.1  41.2  115   3  2   7.9   4.3
  8500   3.6  38.5  080   2  1   9.8   5.4 |   5.6  42.1  110   4  2   7.3   4.0
  8250   4.3  39.7  080   2  1   9.4   5.1 |   6.1  43.0  105   4  2   6.6   3.6
  8000   5.0  41.0  080   2  1   9.6   5.3 |   6.6  43.9  100   4  2   7.3   4.0
  7750   5.7  42.3  085   2  1  10.2   5.6 |   7.2  45.0  100   3  2   8.3   4.5
  7500   6.5  43.7  085   2  1  10.2   5.6 |   7.8  46.0  100   3  2   9.2   5.1
  7250   7.2  45.0  085   2  1  10.1   5.6 |   8.5  47.3  100   3  2  10.2   5.6
  7000   8.0  46.4  085   2  1  10.1   5.6 |   9.3  48.7  100   3  2   9.9   5.4
  6750   8.7  47.7  090   1  1  10.6   5.8 |  10.0  50.0  100   3  2   9.9   5.5
  6500   9.6  49.3  090   1  1  11.1   6.1 |  10.8  51.4  100   3  2  10.4   5.7
  6250  10.4  50.7  095   1  1  11.6   6.4 |  11.6  52.9  100   3  2  10.8   5.9
  6000  11.2  52.2  100   1  1   9.9   5.4 |  12.4  54.3  100   3  1  10.3   5.7
  5750  12.0  53.6  105   1  1  12.9   7.1 |  13.1  55.6  105   3  1  10.4   5.7
  5500  13.2  55.8  100   1  1  17.8   9.7 |  13.9  57.0  105   3  1  10.9   6.0
  5250  14.4  57.9  095   1  1  14.0   7.7 |  14.7  58.5  100   3  1  10.5   5.8
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

This product is issued twice per day, once by approximately 0630 MST/0730 MDT
(1330 UTC) and again by approximately 1830 MST/1930 MDT (0130 UTC).  It is not
continuously monitored nor updated after its initial issuance.

The information contained herein is based on rawinsonde observation and/or
numerical weather prediction model data taken at Walker Field in Grand
Junction, Colorado at

                   North Latitude:  39 deg 07 min 00.001 sec
                   West Longitude: 108 deg 31 min 59.998 sec
                   Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado.  Note that some elevations in numerical weather prediction models
differ from actual station elevations, which can lead to data which appear
to be below ground.  Erroneous data such as these should not be used.

The content and format of this report as well as the issuance times are subject
to change without prior notice.  Comments and suggestions are welcome and should
be directed to one of the addresses or phone numbers shown at the bottom of this
page.  To expedite a response to comments, be sure to mention your interest in
the soaring forecast.

DEFINITIONS:

CAPE (Convective Available Potential Energy) - An integrated measure of the
     energy available for convective development, also known as the positive
     area on a thermodynamic diagram.  Units are Joules per kilogram.  Larger
     values are indicative of greater instability and the possibility of
     stronger convective activity, including thunderstorms.  Values around or
     greater than 1000 suggest the possibility of severe weather should
     convective activity develop.

CIN (Convective Inhibition) - An integrated measure of the amount of energy
     needed to initiate convective activity, also known as the negative area on
     a thermodynamic diagram.  Units are Joules per kilogram.  The more negative
     this number, the more energy is required to initiate convection.  This
     inhibitive energy can be overcome through surface heating, cooling aloft,
     lifting mechanisms (orographic, frontal, gravity waves, etc.)

Convective Condensation Level - The height to which an air parcel possessing the
     average saturation mixing ratio in the lowest 4000 feet of the airmass,
     if heated sufficiently from below, will rise dry adiabatically until it
     just becomes saturated.  It estimates the base of cumulus clouds that are
     produced by surface heating only.

Convection Temperature (ConvectionT) - The surface temperature required to make
     the airmass dry adiabatic up to the given level.  It can be considered a
     "trigger temperature" for that level.

Freezing Level - The height where the temperature is zero degrees Celsius.

Height of Stable Layer - The height (between 12,000 and 18,000 feet above
     mean sea level) where the smallest lapse rate exists.  The location and
     existence of this feature is important in the generation of mountain
     waves.

K Index - A measure of stability which combines the temperature difference
     between approximately 5,000 and 18,000 feet above the surface, the amount
     of moisture at approximately 5,000 feet above the surface, and a measure
     of the dryness at approximately 10,000 feet above the surface.  Larger
     positive numbers indicate more instability and a greater likelihood of
     thunderstorm development.  One interpretation of K index values regarding
     soaring in the western United States is given in WMO Technical Note 158
     and is reproduced in the following table:

          below -10    no or weak thermals
           -10 to 5    dry thermals or 1/8 cumulus with moderate thermals
            5 to 15    good soaring conditions
           15 to 20    good soaring conditions with occasional showers
           20 to 30    excellent soaring conditions, but increasing
                       probability of showers and thunderstorms
           above 30    more than 60 percent probability of thunderstorms

Lapse Rate - The change with height of the temperature. Negative values indicate
     inversions.

Lifted Condensation Level - The height to which an air parcel possessing the
     average dew point in the lowest 4000 feet of the airmass and the forecast
     maximum temperature must be lifted dry adiabatically to attain saturation.

Lifted Index (LI) - The difference between the environmental temperature at a
     level approximately 18,000 feet above the surface and the temperature of
     an air parcel lifted dry adiabatically from the surface to its lifted
     condensation level and then pseudoadiabatically thereafter to this same
     level.  The parcel`s initial temperature is the forecast maximum
     temperature and its dew point is the average dew point in the lowest 4000
     feet of the airmass.  Negative values are indicative of instability with
     positive values showing stable conditions.

Lift Rate - An experimental estimate of the strength of thermals.  It is
     computed the same way as the maximum rate of lift but uses the actual
     level rather than the maximum height of thermals in the calculation.
     Also, none of the empirical adjustments based on cloudiness and K-index
     are applied to these calculations.

Maximum Height of Thermals - The height where the dry adiabat through the
     forecast maximum temperature intersects the environmental temperature.

Maximum Rate of Lift - An estimate of the maximum strength of thermals.  It
     is computed from an empirical formula which combines the expected maximum
     height of thermals with the difference in the environmental temperatures
     between the maximum height of thermals and the temperature 4,000 feet
     above the ground.  After this computation, further empirical adjustments
     are made based on the value of the K-index and the amount and opacity of
     middle and high level cloudiness expected between the time of trigger
     temperature and the time of overdevelopment.

Middle/High Clouds - The amount and opacity of middle (altostratus, altocumulus)
     or high (cirrus, cirrostratus, cirrocumulus) clouds.  Broken means that
     between 60% and 90% of the sky is covered by the cloud, with overcast
     conditions occurring when more than 90% of the sky is covered by the cloud.
     Thin implies that the clouds are predominantly transparent, meaning that
     some sunlight is reaching the ground, in contrast to opaque which suggests
     that little sunlight is reaching the ground.

Potential Height of Wave - The minimum of the following two heights:
     1. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind direction changes by 30 degrees or more
     2. Level above the height of stable layer (or 14,000 feet if none exists)
        where the wind speed no longer increases with height

PVA/NVA - Positive vorticity advection (PVA)/negative vorticity advection (NVA)
     on the 500 millibar isobaric surface (approximately 18,000 feet above mean
     sea level).  Weak PVA has been shown to assist in mountain wave soaring.

Soaring Window - The time between the time the trigger temperature is reached
                 and the time of overdevelopment.

Thermal Index - The difference between the environmental temperature and the
     temperature at a particular level determined by following the dry adiabat
     through the forecast maximum temperature up to that level.  Negative values
     are indicative of thermal lift.

Thermal Soaring Index - An adjective rating (for sailplanes) based on the
     computed maximum rate of lift, and the wind speed and middle and high
     cloud cover expected during the soaring window (the time of the trigger
     temperature and the time of overdevelopment) according to the following:

                 Maximum rate of lift        Adjective Rating
                      >= 800 fpm                 Excellent
                 >= 400 and < 800 fpm              Good
                 >= 200 and < 400 fpm              Fair
                       < 200 fpm                   Poor

Time of Overdevelopment - The time one or more of the following phenomena,
     which essentially shut off thermal lift, is expected to occur:
     1. formation of broken to overcast convective cloud cover
     2. formation of scattered to numerous downbursts
     3. initiation of widespread precipitation

Time of Trigger Temperature - The time the surface temperature is expected to
     reach the trigger temperature.

Trigger Temperature - The surface temperature required to make the first 4000
     feet of the atmosphere dry adiabatic.

Wave Soaring Index - An empirical, adjective rating (for sailplanes) which
     attempts to combine a variety of phenomena important in mountain wave
     soaring into a single index number.  Objective points are assigned to
     these phenomena: wind speed and direction at 14,000 ft MSL, the static
     stability in the 12,000-18,000 ft MSL layer, the wind speed gradient above
     the stable layer, jet stream location and frontal and upper trough
     movements.

042613



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