Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 201235
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0635 MDT Friday, April 20, 2018

This forecast is for Friday, April 20, 2018:

If the trigger temperature of 56.6 F/13.6 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 6688 ft MSL (1849 ft AGL)

Forecast maximum temperature................... 56.0 F/13.8 C
Time of trigger temperature.................... 1415 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. None
Thermal soaring outlook for Saturday 04/21..... Fair

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

Remarks...

Sunrise/Sunset.................... 06:30:13 / 19:55:33 MDT
Total possible sunshine........... 13 hr 25 min 19 sec (805 min 19 sec)
Altitude of sun at 13:13:02 MDT... 62.58 degrees

Upper air data from rawinsonde observation taken on 04/20/2018 at 0600 MDT

Freezing level.................. 9444 ft MSL (4605 ft AGL)
Convective condensation level... 16335 ft MSL (11496 ft AGL)
Lifted condensation level....... 13911 ft MSL (9072 ft AGL)
Lifted index.................... +4.7
K index......................... +16.6

Height  Temperature  Wind  Wind Spd  Lapse Rate  ConvectionT  Thermal  Lift Rate
ft MSL  deg C deg F   Dir   kt  m/s  C/km F/kft  deg C deg F   Index    fpm  m/s
--------------------------------------------------------------------------------
 50000  -55.0 -67.0   250   27   14   4.2   2.3  109.3 228.7    54.7      M    M
 45000  -51.5 -60.7   240   25   13  -6.9  -3.8   90.5 194.9    47.0      M    M
 40000  -50.9 -59.6   240   19   10   6.5   3.6   67.1 152.8    35.1      M    M
 38000  -47.3 -53.1   210   21   11   4.3   2.3   63.7 146.7    33.8      M    M
 36000  -47.1 -52.8   185   30   15  -3.2  -1.8   55.3 131.6    28.9      M    M
 34000  -49.0 -56.2   185   44   23  -3.3  -1.8   44.3 111.7    21.8      M    M
 32000  -49.5 -57.1   180   60   31  -3.8  -2.1   35.5  95.9    16.1      M    M
 30000  -49.4 -56.9   175   77   40   9.2   5.0   26.7  80.1    10.0      M    M
 29000  -46.6 -51.9   175   78   40   9.3   5.1   26.6  79.8    10.0      M    M
 28000  -43.9 -47.0   175   75   39   9.1   5.0   26.4  79.4    10.0      M    M
 27000  -41.3 -42.3   175   72   37   8.3   4.6   25.8  78.4     9.6      M    M
 26000  -38.9 -38.0   170   70   36   8.3   4.6   25.2  77.4     9.3      M    M
 25000  -36.3 -33.3   170   67   34   9.6   5.3   24.9  76.8     9.1      M    M
 24000  -33.5 -28.3   165   68   35   9.6   5.2   24.7  76.5     9.1      M    M
 23000  -30.8 -23.4   165   68   35   8.6   4.7   24.4  75.9     9.0      M    M
 22000  -28.3 -18.9   170   69   35   8.4   4.6   24.0  75.2     8.7      M    M
 21000  -25.9 -14.6   170   69   36   8.1   4.4   23.4  74.2     8.3      M    M
 20000  -23.5 -10.3   165   60   31   8.1   4.4   22.9  73.1     7.9      M    M
 19500  -22.3  -8.1   165   54   28   8.1   4.4   22.5  72.6     7.6      M    M
 19000  -21.1  -6.0   160   49   25   8.1   4.4   22.2  72.0     7.4      M    M
 18500  -19.9  -3.8   155   44   22   7.8   4.3   22.0  71.5     7.2      M    M
 18000  -18.6  -1.5   155   40   21  10.2   5.6   21.9  71.3     7.1      M    M
 17500  -17.1   1.2   150   38   19   9.3   5.1   21.9  71.4     7.2      M    M
 17000  -16.1   3.0   150   35   18   5.4   3.0   21.4  70.5     6.8      M    M
 16500  -15.3   4.5   155   30   15   5.7   3.1   20.7  69.2     6.2      M    M
 16000  -14.0   6.8   160   23   12   4.4   2.4   19.7  67.4     5.3      M    M
 15500  -13.7   7.3   170   26   13   1.1   0.6   18.4  65.1     4.2      M    M
 15000  -13.1   8.4   175   30   16   7.7   4.2   17.4  63.3     3.3      M    M
 14500  -11.8  10.8   180   34   18   7.3   4.0   17.2  62.9     3.1      M    M
 14000  -11.5  11.3   185   38   20   2.8   1.6   16.0  60.7     2.0      M    M
 13500  -10.2  13.6   185   41   21   8.1   4.4   15.8  60.4     1.9      M    M
 13000   -9.8  14.4   185   42   22   1.8   1.0   14.7  58.4     0.9      M    M
 12500   -8.6  16.5   180   36   19  11.1   6.1   14.3  57.8     0.6      M    M
 12000   -7.1  19.2   175   31   16   9.2   5.0   14.3  57.8     0.6      M    M
 11500   -5.8  21.6   175   29   15   9.3   5.1   14.2  57.6     0.5      M    M
 11000   -4.4  24.1   170   27   14   9.3   5.1   14.1  57.4     0.4      M    M
 10500   -3.0  26.6   170   24   13   9.3   5.1   14.1  57.3     0.3      M    M
 10250   -2.3  27.9   165   23   12   9.3   5.1   14.0  57.3     0.3      M    M
 10000   -1.6  29.1   165   22   12   9.4   5.2   14.0  57.2     0.3      M    M
  9750   -0.9  30.4   165   22   11   9.8   5.4   14.0  57.2     0.3      M    M
  9500   -0.2  31.6   160   21   11   9.9   5.4   14.0  57.2     0.3      M    M
  9250    0.6  33.1   160   21   11   9.9   5.4   14.0  57.2     0.3      M    M
  9000    1.3  34.3   155   20   10   9.7   5.3   14.0  57.3     0.3      M    M
  8750    2.0  35.6   155   20   10   9.3   5.1   14.0  57.2     0.3      M    M
  8500    2.7  36.9   155   20   10   9.2   5.1   14.0  57.2     0.3      M    M
  8250    3.4  38.1   155   20   10   9.2   5.1   14.0  57.1     0.2      M    M
  8000    4.1  39.4   155   20   10   9.2   5.1   14.0  57.1     0.2      M    M
  7750    4.8  40.6   155   20   10   9.2   5.1   13.9  57.0     0.2      M    M
  7500    5.4  41.7   155   20   10   9.2   5.1   13.9  57.0     0.1      M    M
  7250    6.1  43.0   155   19   10   9.2   5.1   13.8  56.9     0.1      M    M
  7000    6.8  44.2   155   19   10   9.2   5.1   13.8  56.9     0.1      M    M
  6750    7.5  45.5   155   19   10   9.2   5.1   13.8  56.8     0.0      M    M
  6500    8.2  46.8   160   19   10   9.2   5.1   13.7  56.7    -0.0      5  0.0
  6250    8.9  48.0   160   20   10   9.2   5.1   13.7  56.7    -0.1      M    M
  6000    9.6  49.3   165   20   10   9.2   5.1   13.7  56.6    -0.1      M    M
  5750   10.2  50.4   165   19   10   9.2   5.1   13.6  56.5    -0.2      M    M
  5500   10.9  51.6   165   17    9   9.2   5.1   13.6  56.4    -0.2      M    M
  5250   11.6  52.9   165   15    8   9.3   5.1   13.5  56.3    -0.3      M    M
  5000   12.3  54.1   160   13    7   9.1   5.0   13.5  56.3    -0.3      M    M

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

           04/20/2018 at 0900 MDT          |       04/20/2018 at 1200 MDT
                                           |
K index... +22.2  LI... +1.3               | K index... +15.3  LI... +3.9
CAPE... +24.5  CIN... -13.7                | CAPE... +3.3  CIN... -12.5
                                           |
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 -55.0 -67.0  280  19 10   2.7   1.5 | -54.7 -66.5  290  14  7   2.5   1.4
 45000 -50.8 -59.4  265  19 10   2.5   1.4 | -50.8 -59.4  280  11  6   2.9   1.6
 40000 -47.1 -52.8  210  17  9   2.5   1.4 | -46.4 -51.5  265   9  4   3.0   1.6
 38000 -45.7 -50.3  195  19 10   2.1   1.1 | -44.9 -48.8  250   7  4   1.9   1.0
 36000 -44.4 -47.9  185  20 10   2.1   1.2 | -43.7 -46.7  205   5  3   1.9   1.0
 34000 -43.2 -45.8  175  22 11   2.1   1.1 | -42.6 -44.7  165   7  4   1.6   0.9
 32000 -42.1 -43.8  170  27 14   1.7   1.0 | -43.2 -45.8  115   8  4  -1.1  -0.6
 30000 -40.9 -41.6  170  33 17   0.4   0.2 | -43.8 -46.8  090  12  6   0.2   0.1
 29000 -41.2 -42.2  170  40 20  -1.1  -0.6 | -43.4 -46.1  075  17  9   1.6   0.9
 28000 -41.6 -42.9  170  47 24  -1.1  -0.6 | -42.9 -45.2  065  22 11   1.6   0.9
 27000 -41.9 -43.4  175  54 28  -0.8  -0.5 | -42.4 -44.3  060  28 14   1.6   0.9
 26000 -41.2 -42.2  170  54 28   5.5   3.0 | -40.6 -41.1  060  30 15   9.5   5.2
 25000 -39.5 -39.1  165  47 24   5.8   3.2 | -37.7 -35.9  065  29 15   9.7   5.3
 24000 -37.7 -35.9  155  40 21   5.9   3.2 | -34.8 -30.6  070  29 15   9.6   5.3
 23000 -35.5 -31.9  150  37 19   9.6   5.3 | -32.1 -25.8  075  28 15   8.4   4.6
 22000 -32.6 -26.7  145  37 19   9.7   5.3 | -29.6 -21.3  070  28 15   8.4   4.6
 21000 -29.7 -21.5  135  37 19   9.8   5.4 | -27.1 -16.8  065  28 15   8.6   4.7
 20000 -27.1 -16.8  135  36 19   8.6   4.7 | -25.0 -13.0  065  25 13   6.3   3.5
 19500 -25.8 -14.4  135  35 18   8.6   4.7 | -24.1 -11.4  065  23 12   6.3   3.5
 19000 -24.5 -12.1  135  34 18   8.6   4.7 | -23.2  -9.8  070  21 11   6.3   3.5
 18500 -23.2  -9.8  140  34 17   8.8   4.8 | -22.2  -8.0  070  18  9   6.4   3.5
 18000 -22.1  -7.8  140  32 17   6.3   3.4 | -21.4  -6.5  075  16  8   4.5   2.5
 17500 -21.2  -6.2  140  30 16   6.1   3.3 | -20.7  -5.3  085  12  6   4.3   2.3
 17000 -20.3  -4.5  145  28 15   5.9   3.2 | -20.1  -4.2  105  10  5   3.9   2.1
 16500 -19.4  -2.9  150  27 14   5.6   3.1 | -19.6  -3.3  130   8  4   3.1   1.7
 16000 -18.6  -1.5  155  25 13   5.6   3.1 | -19.2  -2.6  165   9  4   3.1   1.7
 15500 -17.7   0.1  165  24 12   5.9   3.3 | -18.1  -0.6  195  12  6   5.0   2.8
 15000 -16.9   1.6  170  23 12   5.8   3.2 | -17.4   0.7  205  14  7   5.9   3.3
 14500 -15.4   4.3  180  19 10   7.2   3.9 | -16.3   2.7  215  14  7   7.5   4.1
 14000 -14.3   6.3  180  16  8   7.5   4.1 | -15.2   4.6  220  14  7   7.7   4.2
 13500 -13.1   8.4  180  15  8   8.8   4.8 | -14.0   6.8  225  13  7   8.4   4.6
 13000 -11.8  10.8  180  13  7   8.7   4.8 | -12.8   9.0  235  12  6   8.4   4.6
 12500 -10.6  12.9  180  13  7   8.4   4.6 | -11.5  11.3  240  12  6   9.3   5.1
 12000  -9.4  15.1  180  13  7   8.3   4.6 | -10.1  13.8  245  12  6   9.1   5.0
 11500  -8.2  17.2  180  13  7   7.4   4.0 |  -8.8  16.2  250  12  6   8.1   4.5
 11000  -7.1  19.2  175  13  7   7.4   4.1 |  -7.6  18.3  250  13  6   8.0   4.4
 10500  -6.0  21.2  180  13  6   7.0   3.9 |  -6.6  20.1  255  13  7   6.8   3.7
 10250  -5.5  22.1  180  12  6   8.5   4.6 |  -6.0  21.2  260  14  7   7.5   4.1
 10000  -4.8  23.4  185  12  6  10.8   5.9 |  -5.4  22.3  260  14  7   8.7   4.7
  9750  -4.0  24.8  185  12  6   9.7   5.3 |  -4.8  23.4  265  14  7   8.0   4.4
  9500  -3.3  26.1  190  12  6   8.8   4.8 |  -4.2  24.4  270  14  7   7.2   4.0
  9250  -2.6  27.3  190  12  6   8.8   4.8 |  -3.7  25.3  270  15  8   7.4   4.1
  9000  -1.9  28.6  195  12  6   9.7   5.3 |  -3.1  26.4  275  15  8   8.1   4.5
  8750  -1.2  29.8  200  12  6   9.8   5.4 |  -2.5  27.5  280  15  8   8.1   4.5
  8500  -0.5  31.1  200  12  6   8.9   4.9 |  -1.9  28.6  280  15  8   7.3   4.0
  8250   0.2  32.4  205  12  6   9.2   5.0 |  -1.3  29.7  285  15  7   7.9   4.3
  8000   0.8  33.4  210  12  6   8.0   4.4 |  -0.7  30.7  290  14  7   8.4   4.6
  7750   1.4  34.5  215  11  6   6.8   3.7 |  -0.1  31.8  290  13  7   8.0   4.4
  7500   1.9  35.4  225  11  6   6.5   3.6 |   0.4  32.7  295  12  6   7.1   3.9
  7250   2.4  36.3  230  11  6   7.1   3.9 |   1.0  33.8  295  11  6   9.4   5.2
  7000   2.9  37.2  240  11  6   7.9   4.4 |   1.8  35.2  300  11  5  11.3   6.2
  6750   3.5  38.3  245  11  5   8.3   4.6 |   2.6  36.7  300  10  5   9.1   5.0
  6500   4.1  39.4  250  10  5   8.8   4.8 |   3.2  37.8  300  10  5   9.1   5.0
  6250   4.8  40.6  255  10  5   9.7   5.3 |   4.0  39.2  300  10  5  10.8   5.9
  6000   5.5  41.9  255  10  5  10.3   5.7 |   4.8  40.6  300   9  5  11.1   6.1
  5750   6.3  43.3  255  10  5  11.3   6.2 |   5.6  42.1  300   9  5  10.8   5.9
  5500   7.1  44.8  260   9  5  10.2   5.6 |   6.5  43.7  300   8  4  11.5   6.3
  5250   7.8  46.0  260   9  5   6.3   3.4 |   7.4  45.3  300   8  4  12.7   6.9
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/20/2018 at 1500 MDT          |       04/20/2018 at 1800 MDT
                                           |
K index... +10.1  LI... +4.4               | K index... +15.6  LI... +3.4
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 -55.0 -67.0  305  18  9   2.9   1.6 | -55.5 -67.9  325  24 12   2.9   1.6
 45000 -50.7 -59.3  310  16  8   2.6   1.4 | -51.2 -60.2  335  25 13   3.0   1.6
 40000 -46.7 -52.1  340  13  7   2.5   1.4 | -46.4 -51.5  345  20 10   3.0   1.7
 38000 -45.5 -49.9  355  12  6   1.3   0.7 | -45.6 -50.1  355  20 10   0.1   0.1
 36000 -44.7 -48.5  015  11  6   1.3   0.7 | -45.5 -49.9  005  23 12   0.1   0.1
 34000 -44.0 -47.2  035  12  6  -0.3  -0.1 | -45.5 -49.9  010  26 13  -0.8  -0.4
 32000 -44.9 -48.8  025  29 15  -1.5  -0.8 | -46.1 -51.0  025  30 16  -1.1  -0.6
 30000 -45.8 -50.4  025  46 24   1.3   0.7 | -46.6 -51.9  030  35 18   4.7   2.6
 29000 -44.2 -47.6  025  48 25   5.5   3.0 | -44.4 -47.9  025  35 18   7.4   4.1
 28000 -42.6 -44.7  025  50 26   5.5   3.0 | -42.2 -44.0  025  35 18   7.5   4.1
 27000 -41.0 -41.8  030  51 26   5.5   3.0 | -39.4 -38.9  020  35 18   7.6   4.2
 26000 -38.4 -37.1  030  47 24   7.7   4.2 | -37.0 -34.6  015  36 19   8.4   4.6
 25000 -36.1 -33.0  035  42 22   7.7   4.2 | -34.5 -30.1  010  37 19   8.4   4.6
 24000 -33.8 -28.8  040  37 19   7.7   4.2 | -32.0 -25.6  005  38 20   8.5   4.7
 23000 -31.6 -24.9  045  31 16   7.3   4.0 | -29.7 -21.5  005  34 17   7.2   4.0
 22000 -29.4 -20.9  050  25 13   7.3   4.0 | -27.6 -17.7  005  28 14   7.2   4.0
 21000 -27.2 -17.0  060  19 10   7.4   4.1 | -25.4 -13.7  360  22 12   6.9   3.8
 20000 -24.9 -12.8  065  17  9   7.9   4.3 | -23.5 -10.3  355  19 10   6.2   3.4
 19500 -23.8 -10.8  065  16  8   7.9   4.3 | -22.6  -8.7  355  18  9   6.3   3.4
 19000 -22.6  -8.7  060  15  8   7.9   4.4 | -21.7  -7.1  350  16  8   6.3   3.5
 18500 -21.5  -6.7  060  15  8   8.0   4.4 | -20.8  -5.4  345  15  8   6.6   3.6
 18000 -20.4  -4.7  055  13  7   6.6   3.6 | -19.7  -3.5  345  14  7   8.3   4.5
 17500 -19.4  -2.9  040  12  6   6.8   3.7 | -18.5  -1.3  345  14  7   8.4   4.6
 17000 -18.5  -1.3  025  12  6   4.4   2.4 | -17.5   0.5  340  13  7   4.4   2.4
 16500 -18.0  -0.4  010   8  4   3.7   2.0 | -16.9   1.6  330  13  7   3.8   2.1
 16000 -17.4   0.7  340   6  3   4.2   2.3 | -16.4   2.5  320  13  7   4.2   2.3
 15500 -16.6   2.1  300   5  3   5.6   3.1 | -15.7   3.7  310  14  7   4.8   2.6
 15000 -15.8   3.6  265   7  4   5.6   3.1 | -15.0   5.0  300  15  8   5.2   2.9
 14500 -14.8   5.4  255   9  5   8.1   4.4 | -13.9   7.0  295  15  8   8.3   4.5
 14000 -13.6   7.5  260  11  6   8.0   4.4 | -12.7   9.1  290  16  8   8.1   4.5
 13500 -12.5   9.5  260  12  6   6.7   3.7 | -11.6  11.1  290  16  8   6.7   3.7
 13000 -11.0  12.2  270  14  7   6.6   3.6 | -10.1  13.8  285  17  8   6.9   3.8
 12500 -10.1  13.8  275  15  8   6.2   3.4 |  -9.1  15.6  285  17  9   6.9   3.8
 12000  -9.2  15.4  280  16  8   6.5   3.6 |  -8.1  17.4  285  18  9   7.0   3.8
 11500  -8.1  17.4  280  16  8   7.1   3.9 |  -7.0  19.4  285  19 10   7.1   3.9
 11000  -7.1  19.2  285  16  8   7.2   4.0 |  -6.0  21.2  285  20 10   6.4   3.5
 10500  -5.9  21.4  280  15  8   6.9   3.8 |  -5.1  22.8  285  20 10   4.9   2.7
 10250  -5.4  22.3  280  15  8   9.6   5.2 |  -4.7  23.5  285  20 10   8.8   4.8
 10000  -4.6  23.7  280  14  7  10.3   5.6 |  -3.9  25.0  285  20 10   9.6   5.2
  9750  -3.9  25.0  280  14  7   8.1   4.4 |  -3.4  25.9  290  19 10   6.2   3.4
  9500  -3.3  26.1  280  14  7   8.7   4.8 |  -2.9  26.8  290  19 10   7.0   3.8
  9250  -2.6  27.3  280  14  7   8.3   4.6 |  -2.4  27.7  290  19 10   7.2   3.9
  9000  -2.1  28.2  280  14  7   8.5   4.7 |  -1.8  28.8  290  18  9   8.3   4.5
  8750  -1.4  29.5  280  14  7   8.9   4.9 |  -1.2  29.8  290  18  9   8.7   4.7
  8500  -0.8  30.6  280  14  7   8.7   4.8 |  -0.6  30.9  290  17  9   8.4   4.6
  8250  -0.1  31.8  280  13  7   9.4   5.1 |   0.0  32.0  290  17  9   9.0   4.9
  8000   0.6  33.1  280  13  7  10.2   5.6 |   0.7  33.3  290  17  9   9.6   5.3
  7750   1.4  34.5  280  13  7  10.0   5.5 |   1.4  34.5  290  17  9   9.4   5.2
  7500   2.1  35.8  280  13  7   9.9   5.4 |   2.1  35.8  290  17  9   9.5   5.2
  7250   2.9  37.2  280  13  7  10.4   5.7 |   2.9  37.2  290  17  9  10.0   5.5
  7000   3.6  38.5  280  13  7  10.7   5.9 |   3.6  38.5  290  16  8  10.2   5.6
  6750   4.4  39.9  275  13  7  10.3   5.7 |   4.4  39.9  290  16  8   9.4   5.1
  6500   5.2  41.4  275  13  7  10.8   5.9 |   5.1  41.2  290  16  8  10.1   5.5
  6250   6.1  43.0  275  12  6  11.8   6.5 |   5.9  42.6  290  16  8  11.4   6.2
  6000   6.9  44.4  275  12  6  11.4   6.2 |   6.7  44.1  290  15  8  11.1   6.1
  5750   7.8  46.0  275  12  6  11.2   6.2 |   7.5  45.5  290  15  8  10.6   5.8
  5500   8.7  47.7  275  11  6  15.4   8.4 |   8.3  46.9  290  14  7  10.7   5.9
  5250  10.1  50.2  275  12  6  20.8  11.4 |   9.1  48.4  290  14  7  11.4   6.3
  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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