Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 011246
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0646 MDT Friday, May 1, 2015

This forecast is for Friday, May 1, 2015:

If the trigger temperature of 73.8 F/23.2 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1187 ft/min (6.0 m/s)
   Maximum height of thermals.................. 18352 ft MSL (13513 ft AGL)

Forecast maximum temperature................... 81.0 F/27.7 C
Time of trigger temperature.................... 1130 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 13751 ft MSL (8911 ft AGL)
Thermal soaring outlook for Saturday 05/02..... Excellent

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

Remarks...

Sunrise/Sunset.................... 06:16:14 / 20:06:02 MDT
Total possible sunshine........... 13 hr 49 min 47 sec (829 min 47 sec)
Altitude of sun at 13:11:19 MDT... 66.03 degrees

Upper air data from rawinsonde observation taken on 05/01/2015 at 0600 MDT

Freezing level.................. 12767 ft MSL (7928 ft AGL)
Convective condensation level... 15192 ft MSL (10353 ft AGL)
Lifted condensation level....... 16038 ft MSL (11199 ft AGL)
Lifted index.................... -2.3
K index......................... +23.3

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  -59.6 -75.3   265   26   13   1.0   0.6  102.0 215.5    42.6      M    M
 45000  -62.2 -80.0   250   35   18  -0.5  -0.3   71.5 160.8    27.1      M    M
 40000  -64.0 -83.2   245   37   19   4.6   2.5   45.6 114.2    12.1      M    M
 38000  -60.6 -77.1   255   46   24   7.4   4.0   42.0 107.5    10.0      M    M
 36000  -56.3 -69.3   255   40   21   7.1   3.9   39.5 103.0     8.5      M    M
 34000  -51.7 -61.1   255   34   18   8.7   4.8   37.8 100.0     7.5      M    M
 32000  -45.9 -50.6   255   29   15   8.7   4.8   36.9  98.4     7.1      M    M
 30000  -40.5 -40.9   260   29   15   9.3   5.1   36.2  97.2     6.8      M    M
 29000  -38.0 -36.4   260   27   14   8.0   4.4   35.6  96.1     6.4      M    M
 28000  -35.6 -32.1   255   26   13   6.9   3.8   34.9  94.9     5.9      M    M
 27000  -33.6 -28.5   255   24   12   8.2   4.5   33.8  92.8     5.1      M    M
 26000  -31.2 -24.2   255   23   12   8.1   4.5   33.1  91.6     4.6      M    M
 25000  -28.8 -19.8   250   21   11   7.3   4.0   32.5  90.5     4.1      M    M
 24000  -25.8 -14.4   250   16    8   8.5   4.6   32.7  90.8     4.3      M    M
 23000  -23.2  -9.8   255   17    9   8.7   4.8   32.2  90.0     3.9      M    M
 22000  -20.6  -5.1   260   18    9   8.2   4.5   31.9  89.3     3.6      M    M
 21000  -18.9  -2.0   260   19   10   5.6   3.1   30.5  86.9     2.5      M    M
 20000  -17.2   1.0   265   20   10   5.7   3.1   29.1  84.3     1.3      M    M
 19500  -16.4   2.5   265   20   10   7.0   3.8   28.3  83.0     0.7      M    M
 19000  -15.1   4.8   265   19   10   8.7   4.8   28.1  82.6     0.5      M    M
 18500  -13.9   7.0   265   19   10   7.5   4.1   27.8  82.1     0.2      M    M
 18000  -12.8   9.0   270   18    9   7.7   4.2   27.4  81.4    -0.2   1265  6.4
 17500  -11.1  12.0   275   18    9   8.4   4.6   27.0  80.5    -0.6   1191  6.1
 17000   -9.8  14.4   280   17    9   8.4   4.6   26.7  80.1    -0.8   1138  5.8
 16500   -8.6  16.5   280   17    9   8.6   4.7   26.5  79.8    -1.0   1086  5.5
 16000   -7.3  18.9   285   17    9   8.9   4.9   26.4  79.4    -1.2   1033  5.2
 15500   -6.1  21.0   280   17    9   6.9   3.8   26.1  78.9    -1.5    984  5.0
 15000   -5.1  22.8   280   16    8   7.0   3.8   25.6  78.1    -2.0    939  4.8
 14500   -4.1  24.6   270    9    4   7.0   3.8   25.2  77.3    -2.4    893  4.5
 14000   -3.0  26.6   230    3    2   7.0   3.9   24.7  76.5    -2.8    847  4.3
 13500   -2.0  28.4   220    4    2   7.4   4.1   24.3  75.7    -3.3    801  4.1
 13000   -0.6  30.9   210    5    3  10.7   5.8   24.2  75.6    -3.3    744  3.8
 12500    1.0  33.8   210    6    3  10.4   5.7   24.3  75.8    -3.3    682  3.5
 12000    2.5  36.5   205    7    4  10.3   5.6   24.4  76.0    -3.2    621  3.2
 11500    4.0  39.2   200    9    4   9.1   5.0   24.4  75.9    -3.2    563  2.9
 11000    5.3  41.5   200   10    5   9.2   5.1   24.3  75.8    -3.3    507  2.6
 10500    6.7  44.1   205    9    5   9.1   5.0   24.3  75.7    -3.4    451  2.3
 10250    7.4  45.3   210    9    5   9.5   5.2   24.2  75.6    -3.5    423  2.2
 10000    8.1  46.6   215   10    5   9.8   5.4   24.2  75.6    -3.5    394  2.0
  9750    8.8  47.8   210    9    5   9.8   5.4   24.2  75.6    -3.5    365  1.9
  9500    9.6  49.3   205    8    4   9.6   5.2   24.2  75.6    -3.5    336  1.7
  9250   10.2  50.4   200    8    4   8.4   4.6   24.2  75.5    -3.5    308  1.6
  9000   10.8  51.4   190    7    4   7.8   4.3   24.0  75.3    -3.7    283  1.4
  8750   11.4  52.5   180    6    3   8.0   4.4   23.9  75.0    -3.9    259  1.3
  8500   12.0  53.6   165    5    3   7.8   4.3   23.7  74.7    -4.0    234  1.2
  8250   12.6  54.7   145    5    2   8.4   4.6   23.6  74.5    -4.2    209  1.1
  8000   13.1  55.6   130    5    3   6.4   3.5   23.5  74.3    -4.3    184  0.9
  7750   13.4  56.1   110    6    3   1.2   0.7   23.0  73.4    -4.8    169  0.9
  7500   13.4  56.1   100    8    4   0.9   0.5   22.3  72.1    -5.6    162  0.8
  7250   13.6  56.5   095   10    5   4.5   2.4   21.7  71.1    -6.1    149  0.8
  7000   14.0  57.2   090   13    6   5.5   3.0   21.4  70.5    -6.5    130  0.7
  6750   14.4  57.9   085   12    6   5.2   2.9   21.1  69.9    -6.8    111  0.6
  6500   14.7  58.5   080   11    6   5.3   2.9   20.7  69.3    -7.2     92  0.5
  6250   15.1  59.2   075   11    6   5.3   2.9   20.4  68.7    -7.6     73  0.4
  6000   15.5  59.9   065   10    5   5.4   2.9   20.1  68.1    -7.9     55  0.3
  5750   15.9  60.6   065    8    4   5.2   2.8   19.7  67.5    -8.3     36  0.2
  5500   16.3  61.3   060    6    3   5.9   3.2   19.4  66.9    -8.7     17  0.1
  5250   16.5  61.7   050    4    2  -0.2  -0.1   19.0  66.1    -9.1      1  0.0
  5000   16.0  60.8   020    2    1 -11.4  -6.2   17.8  64.0   -10.4      9  0.0

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

           05/01/2015 at 0900 MDT          |       05/01/2015 at 1200 MDT
                                           |
K index... +22.1  LI... +272.5             | K index... +22.8  LI... +271.4
CAPE... +40.4  CIN... -28.4                | CAPE... +230.1  CIN... -32.1
                                           |
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 -61.7 -79.1  260  28 14  -0.3  -0.1 | -61.2 -78.2  255  26 13  -0.7  -0.4
 45000 -62.1 -79.8  255  37 19  -0.6  -0.3 | -62.2 -80.0  260  35 18  -0.3  -0.2
 40000 -63.0 -81.4  250  38 20  -0.3  -0.2 | -62.7 -80.9  255  41 21  -0.1  -0.1
 38000 -60.0 -76.0  250  36 19   6.8   3.7 | -59.8 -75.6  255  38 20   6.5   3.6
 36000 -55.9 -68.6  255  33 17   6.8   3.7 | -55.9 -68.6  260  34 17   6.5   3.6
 34000 -51.4 -60.5  255  31 16   8.5   4.7 | -51.5 -60.7  260  31 16   8.5   4.7
 32000 -46.3 -51.3  255  29 15   8.5   4.6 | -45.8 -50.4  265  31 16   8.5   4.7
 30000 -40.6 -41.1  260  27 14   8.4   4.6 | -40.6 -41.1  265  29 15   8.6   4.7
 29000 -38.1 -36.6  260  25 13   8.4   4.6 | -38.1 -36.6  265  28 15   8.6   4.7
 28000 -35.6 -32.1  260  24 12   8.4   4.6 | -35.5 -31.9  265  27 14   8.6   4.7
 27000 -33.2 -27.8  260  23 12   7.7   4.2 | -33.0 -27.4  265  27 14   8.2   4.5
 26000 -30.9 -23.6  260  23 12   7.7   4.2 | -30.6 -23.1  265  26 13   8.2   4.5
 25000 -28.6 -19.5  260  22 11   7.7   4.2 | -28.1 -18.6  270  25 13   8.2   4.5
 24000 -26.3 -15.3  260  22 11   7.9   4.3 | -25.8 -14.4  270  24 12   6.8   3.7
 23000 -24.0 -11.2  265  21 11   7.9   4.3 | -23.8 -10.8  270  23 12   6.9   3.8
 22000 -21.7  -7.1  265  20 11   7.9   4.3 | -21.7  -7.1  270  23 12   6.9   3.8
 21000 -19.4  -2.9  265  20 10   7.4   4.1 | -19.5  -3.1  270  22 11   7.7   4.2
 20000 -17.2   1.0  270  19 10   7.4   4.1 | -17.2   1.0  270  21 11   7.7   4.2
 19500 -16.1   3.0  275  19 10   7.4   4.1 | -16.1   3.0  265  20 11   7.7   4.2
 19000 -14.9   5.2  275  18  9   7.6   4.1 | -14.9   5.2  265  20 10   7.8   4.3
 18500 -13.8   7.2  275  18  9   8.0   4.4 | -13.8   7.2  265  20 10   8.0   4.4
 18000 -12.6   9.3  280  18  9   7.9   4.4 | -12.6   9.3  265  19 10   8.0   4.4
 17500 -11.4  11.5  280  18  9   8.1   4.5 | -11.5  11.3  260  19 10   8.2   4.5
 17000 -10.2  13.6  280  17  9   8.2   4.5 | -10.3  13.5  260  19 10   8.2   4.5
 16500  -9.0  15.8  280  16  8   8.2   4.5 |  -9.1  15.6  260  18  9   8.6   4.7
 16000  -7.8  18.0  280  15  8   8.3   4.6 |  -7.7  18.1  260  17  9   8.9   4.9
 15500  -6.6  20.1  280  14  7   8.3   4.6 |  -6.4  20.5  260  17  9   8.9   4.9
 15000  -5.4  22.3  275  13  7   8.2   4.5 |  -4.5  23.9  260  16  8   8.6   4.7
 14500  -3.6  25.5  270  13  7   8.5   4.6 |  -3.2  26.2  255  16  8   8.7   4.8
 14000  -2.3  27.9  270  13  7   8.9   4.9 |  -1.9  28.6  255  15  8   8.7   4.8
 13500  -1.0  30.2  265  13  7   9.0   4.9 |  -0.7  30.7  255  15  8   8.8   4.8
 13000   0.3  32.5  265  13  7   9.1   5.0 |   0.6  33.1  255  14  7   9.0   5.0
 12500   1.6  34.9  265  13  7   9.1   5.0 |   2.0  35.6  255  14  7   9.1   5.0
 12000   3.0  37.4  265  12  6   8.9   4.9 |   3.3  37.9  255  13  7   9.2   5.0
 11500   4.3  39.7  265  11  5   8.9   4.9 |   4.6  40.3  255  12  6   9.1   5.0
 11000   5.5  41.9  265   8  4   6.8   3.7 |   5.9  42.6  255  10  5   8.1   4.4
 10500   6.5  43.7  260   6  3   4.8   2.6 |   7.2  45.0  250   9  5   4.8   2.7
 10250   6.8  44.2  250   5  2   5.5   3.0 |   7.4  45.3  250   8  4   5.4   3.0
 10000   7.4  45.3  245   4  2   9.1   5.0 |   8.1  46.6  250   7  4  10.2   5.6
  9750   8.0  46.4  240   4  2   8.5   4.7 |   8.8  47.8  245   7  3   9.1   5.0
  9500   8.7  47.7  230   3  2   8.2   4.5 |   9.4  48.9  240   6  3   8.8   4.8
  9250   9.2  48.6  220   3  2   6.9   3.8 |  10.0  50.0  235   5  2   7.0   3.9
  9000   9.8  49.6  215   3  1   7.7   4.2 |  10.5  50.9  230   4  2   7.2   3.9
  8750  10.4  50.7  210   3  1   8.8   4.9 |  11.1  52.0  220   4  2   7.8   4.3
  8500  11.0  51.8  205   2  1   8.1   4.4 |  11.7  53.1  210   3  2   7.6   4.2
  8250  11.5  52.7  195   2  1   7.8   4.3 |  12.2  54.0  205   3  1   7.3   4.0
  8000  12.1  53.8  180   2  1   6.4   3.5 |  12.8  55.0  195   3  1   7.8   4.3
  7750  12.5  54.5  175   2  1   5.4   3.0 |  13.4  56.1  190   2  1   8.0   4.4
  7500  12.8  55.0  165   3  1   4.1   2.3 |  13.9  57.0  185   2  1   9.1   5.0
  7250  13.1  55.6  160   3  2   2.6   1.4 |  14.7  58.5  185   2  1  10.5   5.8
  7000  13.3  55.9  150   4  2   2.9   1.6 |  15.4  59.7  190   2  1   9.8   5.4
  6750  13.5  56.3  150   5  2   2.9   1.6 |  16.1  61.0  190   2  1   9.9   5.5
  6500  13.7  56.7  145   5  3   3.1   1.7 |  16.9  62.4  190   2  1  10.9   6.0
  6250  14.0  57.2  140   5  2   3.8   2.1 |  17.8  64.0  190   2  1  12.1   6.7
  6000  14.2  57.6  130   4  2   1.5   0.8 |  18.6  65.5  195   2  1   9.7   5.3
  5750  14.2  57.6  120   4  2   4.8   2.6 |  19.3  66.7  195   2  1  10.9   6.0
  5500  14.9  58.8  120   4  2  10.9   6.0 |  20.3  68.5  195   2  1  15.0   8.2
  5250  15.6  60.1  115   4  2   6.4   3.5 |  21.3  70.3  195   2  1  12.4   6.8
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/01/2015 at 1500 MDT          |       05/01/2015 at 1800 MDT
                                           |
K index... +21.5  LI... +271.8             | K index... +16.6  LI... +272.4
CAPE... +255.6  CIN... -36.7               | CAPE... +87.1  CIN... -78.1
                                           |
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 -61.5 -78.7  250  26 13  -0.5  -0.3 | -61.8 -79.2  255  30 15   0.2   0.1
 45000 -62.4 -80.3  255  34 17  -0.8  -0.4 | -61.6 -78.9  255  36 18  -1.6  -0.9
 40000 -63.5 -82.3  255  37 19  -0.5  -0.3 | -63.9 -83.0  255  33 17  -1.2  -0.7
 38000 -60.4 -76.7  255  35 18   7.2   4.0 | -60.7 -77.3  260  31 16   7.6   4.1
 36000 -56.1 -69.0  260  31 16   7.2   4.0 | -56.2 -69.2  260  30 15   7.6   4.1
 34000 -51.3 -60.3  260  29 15   8.8   4.8 | -51.3 -60.3  260  28 15   8.8   4.8
 32000 -45.4 -49.7  265  29 15   8.7   4.8 | -46.0 -50.8  265  28 14   8.8   4.8
 30000 -40.3 -40.5  270  28 15   8.4   4.6 | -40.1 -40.2  270  27 14   8.5   4.7
 29000 -37.8 -36.0  270  28 14   8.4   4.6 | -37.6 -35.7  270  26 13   8.5   4.7
 28000 -35.3 -31.5  270  27 14   8.4   4.6 | -35.0 -31.0  270  25 13   8.5   4.7
 27000 -32.8 -27.0  270  27 14   8.4   4.6 | -32.5 -26.5  270  26 13   8.2   4.5
 26000 -30.3 -22.5  270  28 14   8.4   4.6 | -30.1 -22.2  275  26 14   8.2   4.5
 25000 -27.7 -17.9  270  28 14   8.4   4.6 | -27.6 -17.7  275  27 14   8.3   4.5
 24000 -25.3 -13.5  270  28 14   8.1   4.4 | -25.2 -13.4  275  28 14   8.1   4.4
 23000 -22.8  -9.0  275  27 14   8.1   4.4 | -22.8  -9.0  275  28 14   8.1   4.4
 22000 -20.4  -4.7  275  26 14   8.1   4.4 | -20.4  -4.7  275  28 14   8.1   4.4
 21000 -18.2  -0.8  270  25 13   7.1   3.9 | -18.1  -0.6  275  28 14   7.0   3.9
 20000 -16.1   3.0  270  24 13   7.0   3.9 | -16.0   3.2  270  27 14   7.0   3.8
 19500 -15.0   5.0  270  24 12   7.1   3.9 | -14.9   5.2  265  27 14   7.0   3.9
 19000 -14.0   6.8  265  23 12   7.4   4.1 | -13.9   7.0  265  27 14   7.4   4.1
 18500 -12.8   9.0  265  23 12   8.3   4.6 | -12.7   9.1  260  27 14   8.5   4.7
 18000 -11.5  11.3  260  23 12   8.3   4.6 | -11.4  11.5  260  27 14   8.5   4.7
 17500 -10.3  13.5  260  23 12   8.3   4.6 | -10.1  13.8  260  27 14   8.8   4.8
 17000  -9.1  15.6  255  24 12   8.4   4.6 |  -8.8  16.2  260  27 14   8.8   4.9
 16500  -7.9  17.8  255  24 12   8.2   4.5 |  -7.5  18.5  255  27 14   8.8   4.9
 16000  -6.7  19.9  255  24 12   8.1   4.4 |  -6.3  20.7  255  27 14   8.8   4.8
 15500  -5.5  22.1  255  23 12   8.1   4.5 |  -5.0  23.0  255  26 14   8.8   4.8
 15000  -3.7  25.3  255  22 11   8.4   4.6 |  -3.7  25.3  255  26 13   8.9   4.9
 14500  -2.5  27.5  255  21 11   8.3   4.6 |  -1.7  28.9  255  24 12   8.9   4.9
 14000  -1.3  29.7  255  20 10   8.2   4.5 |  -0.4  31.3  260  23 12   8.9   4.9
 13500  -0.1  31.8  255  18  9   8.2   4.5 |   0.9  33.6  260  22 11   8.9   4.9
 13000   1.1  34.0  255  17  9   8.4   4.6 |   2.2  36.0  260  21 11   8.8   4.8
 12500   2.3  36.1  255  16  8   8.4   4.6 |   3.5  38.3  265  19 10   8.8   4.8
 12000   3.6  38.5  255  15  8   9.0   4.9 |   4.8  40.6  265  18  9   8.1   4.5
 11500   4.9  40.8  255  14  7   8.9   4.9 |   6.0  42.8  270  17  9   8.3   4.6
 11000   6.2  43.2  255  13  7   8.2   4.5 |   7.1  44.8  275  16  8   6.9   3.8
 10500   7.5  45.5  255  11  6   5.2   2.8 |   8.1  46.6  280  14  7   9.8   5.4
 10250   7.7  45.9  255  10  5   6.0   3.3 |   8.9  48.0  280  14  7  10.4   5.7
 10000   8.4  47.1  255   9  5  10.7   5.9 |   9.5  49.1  285  13  7   7.0   3.9
  9750   9.2  48.6  255   9  4   9.7   5.3 |  10.1  50.2  285  12  6   8.0   4.4
  9500   9.9  49.8  250   8  4   9.1   5.0 |  10.7  51.3  290  11  6   7.6   4.2
  9250  10.5  50.9  250   7  4   7.3   4.0 |  11.2  52.2  295  10  5   6.8   3.7
  9000  11.0  51.8  250   7  3   8.6   4.7 |  11.7  53.1  295   9  5   6.9   3.8
  8750  11.7  53.1  250   6  3   9.8   5.4 |  12.2  54.0  300   8  4   7.3   4.0
  8500  12.4  54.3  250   6  3   9.7   5.3 |  12.7  54.9  305   7  3   7.6   4.2
  8250  13.1  55.6  250   6  3  10.5   5.7 |  13.3  55.9  305   6  3   9.4   5.2
  8000  13.9  57.0  250   6  3   9.8   5.4 |  14.0  57.2  305   5  3   9.8   5.4
  7750  14.6  58.3  245   6  3   8.7   4.8 |  14.7  58.5  305   5  3   9.2   5.0
  7500  15.3  59.5  245   6  3   9.9   5.4 |  15.4  59.7  305   5  3   9.6   5.2
  7250  16.1  61.0  245   6  3  11.1   6.1 |  16.1  61.0  305   5  3   9.9   5.4
  7000  16.9  62.4  245   6  3  10.4   5.7 |  16.8  62.2  300   5  3   9.7   5.3
  6750  17.6  63.7  245   6  3   9.7   5.3 |  17.5  63.5  300   5  3   9.4   5.1
  6500  18.4  65.1  245   6  3  10.6   5.8 |  18.3  64.9  300   5  2  10.1   5.5
  6250  19.2  66.6  245   6  3  11.5   6.3 |  19.0  66.2  300   5  2  10.7   5.9
  6000  20.0  68.0  245   6  3  10.1   5.6 |  19.8  67.6  300   5  2  10.6   5.8
  5750  20.8  69.4  245   6  3  11.5   6.3 |  20.6  69.1  295   4  2  10.3   5.7
  5500  21.8  71.2  245   6  3  15.1   8.3 |  21.4  70.5  295   4  2   9.9   5.4
  5250  22.9  73.2  245   6  3  14.3   7.8 |  22.1  71.8  300   5  2   9.9   5.4
  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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