Soaring Guidance
Issued by NWS Grand Junction, CO

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000
UXUS97 KGJT 291236
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0636 MDT Saturday, April 29, 2017

This forecast is for Saturday, April 29, 2017:

If the trigger temperature of 43.2 F/6.2 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 690 ft/min (3.5 m/s)
   Maximum height of thermals.................. 15745 ft MSL (10906 ft AGL)

Forecast maximum temperature................... 56.0 F/13.8 C
Time of trigger temperature.................... 1045 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 11301 ft MSL (6462 ft AGL)
Thermal soaring outlook for Sunday 04/30....... Fair

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

Remarks...

Sunrise/Sunset.................... 06:18:04 / 20:04:35 MDT
Total possible sunshine........... 13 hr 46 min 32 sec (826 min 32 sec)
Altitude of sun at 13:11:30 MDT... 65.58 degrees

Upper air data from rawinsonde observation taken on 04/29/2017 at 0600 MDT

Freezing level.................. 6656 ft MSL (1817 ft AGL)
Convective condensation level... 9676 ft MSL (4837 ft AGL)
Lifted condensation level....... 12210 ft MSL (7370 ft AGL)
Lifted index.................... -3.3
K index......................... +18.9

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  -53.7 -64.7   285   13    7  -0.5  -0.3  113.8 236.8    57.0      M    M
 45000  -50.4 -58.7   310   16    8  -0.8  -0.5   93.3 199.9    48.6      M    M
 40000  -48.0 -54.4   270   17    9  -0.2  -0.1   73.9 165.0    39.3      M    M
 38000  -48.2 -54.8   260   15    8  -0.5  -0.3   64.7 148.4    34.2      M    M
 36000  -46.3 -51.3   205    7    3   5.7   3.1   58.9 138.0    31.1      M    M
 34000  -46.4 -51.5   160   10    5   3.3   1.8   50.2 122.4    25.9      M    M
 32000  -45.6 -50.1   140   19   10  -4.7  -2.6   42.1 107.8    20.8      M    M
 30000  -46.6 -51.9   170   14    7   2.9   1.6   32.8  91.0    14.4      M    M
 29000  -45.2 -49.4   160   16    8   4.1   2.2   30.6  87.2    13.0      M    M
 28000  -44.6 -48.3   160   21   11   2.3   1.3   27.6  81.6    10.8      M    M
 27000  -45.3 -49.5   155   16    8  -0.6  -0.3   22.9  73.2     7.4      M    M
 26000  -45.7 -50.3   085   15    8   2.5   1.4   18.6  65.5     4.1      M    M
 25000  -43.6 -46.5   085   17    9   7.8   4.3   17.6  63.7     3.4      M    M
 24000  -41.1 -42.0   090   16    8   9.2   5.0   17.0  62.7     3.0      M    M
 23000  -38.3 -36.9   095   15    7   9.7   5.3   16.9  62.4     2.8      M    M
 22000  -35.4 -31.7   090   13    7   9.7   5.3   16.8  62.3     2.8      M    M
 21000  -32.7 -26.9   090   12    6   8.8   4.8   16.6  61.8     2.6      M    M
 20000  -30.1 -22.2   085   10    5   8.8   4.8   16.3  61.3     2.4      M    M
 19500  -28.8 -19.8   080   10    5   8.8   4.8   16.1  60.9     2.2      M    M
 19000  -27.5 -17.5   075   10    5   8.8   4.8   15.9  60.5     2.1      M    M
 18500  -26.2 -15.2   070   11    5   8.1   4.5   15.6  60.2     1.9      M    M
 18000  -24.5 -12.1   065   11    6   7.0   3.8   15.1  59.1     1.4      M    M
 17500  -23.2  -9.8   075   11    6   9.6   5.3   14.8  58.7     1.2      M    M
 17000  -21.9  -7.4   075   11    5   8.4   4.6   14.7  58.5     1.1      M    M
 16500  -20.9  -5.6   060    9    4   6.3   3.5   14.3  57.7     0.7      M    M
 16000  -19.9  -3.8   040    8    4   6.3   3.5   13.7  56.7     0.2      M    M
 15500  -18.8  -1.8   035    7    4   8.9   4.9   13.4  56.1    -0.2    856  4.3
 15000  -17.5   0.5   040    6    3   8.4   4.6   13.2  55.8    -0.3    802  4.1
 14500  -16.4   2.5   050    8    4   6.0   3.3   12.7  54.9    -0.8    756  3.8
 14000  -15.4   4.3   060   10    5   8.2   4.5   12.3  54.2    -1.2    710  3.6
 13500  -14.2   6.4   070   10    5   8.1   4.4   12.0  53.6    -1.5    659  3.3
 13000  -13.0   8.6   080   11    5   8.1   4.4   11.7  53.1    -1.7    609  3.1
 12500  -11.8  10.8   090   11    6   8.1   4.4   11.5  52.7    -2.0    558  2.8
 12000  -10.6  12.9   095   12    6   7.9   4.3   11.3  52.3    -2.2    507  2.6
 11500   -9.4  15.1   085   15    8   4.6   2.5   11.0  51.8    -2.5    456  2.3
 11000   -9.3  15.3   080   18    9  -0.5  -0.3    9.5  49.1    -3.9    439  2.2
 10500   -8.9  16.0   080   21   11   6.7   3.7    8.4  47.1    -5.0    412  2.1
 10250   -8.4  16.9   075   22   12   5.9   3.3    8.1  46.6    -5.3    391  2.0
 10000   -8.0  17.6   075   24   12   6.2   3.4    7.8  46.1    -5.6    370  1.9
  9750   -7.5  18.5   070   22   11   6.6   3.6    7.6  45.6    -5.9    349  1.8
  9500   -7.0  19.4   065   22   11   6.9   3.8    7.3  45.2    -6.1    327  1.7
  9250   -6.5  20.3   065   21   11   6.9   3.8    7.1  44.8    -6.4    304  1.5
  9000   -6.0  21.2   060   21   11   6.9   3.8    6.9  44.4    -6.6    282  1.4
  8750   -5.5  22.1   055   20   10   6.9   3.8    6.7  44.0    -6.8    259  1.3
  8500   -5.0  23.0   050   19   10   6.7   3.7    6.4  43.6    -7.1    237  1.2
  8250   -4.5  23.9   045   18   10   7.4   4.1    6.2  43.2    -7.3    215  1.1
  8000   -3.9  25.0   035   18    9   9.1   5.0    6.1  43.0    -7.5    189  1.0
  7750   -3.2  26.2   035   16    8   9.6   5.2    6.1  42.9    -7.5    161  0.8
  7500   -2.5  27.5   035   14    7   9.4   5.2    6.1  42.9    -7.6    132  0.7
  7250   -1.8  28.8   040   12    6   9.5   5.2    6.0  42.9    -7.6    104  0.5
  7000   -1.1  30.0   040   10    5   9.5   5.2    6.0  42.8    -7.7     76  0.4
  6750   -0.4  31.3   035    9    5   9.5   5.2    6.0  42.8    -7.7     47  0.2
  6500    0.3  32.5   025    7    4   9.5   5.2    6.0  42.7    -7.8     19  0.1
  6250    1.0  33.8   010    6    3   9.4   5.2    5.9  42.7    -7.9      M    M
  6000    1.7  35.1   350    6    3   9.6   5.3    5.9  42.7    -7.9      M    M
  5750    2.4  36.3   340    5    3   9.1   5.0    5.9  42.6    -8.0      M    M
  5500    2.9  37.2   335    5    2   5.6   3.1    5.7  42.3    -8.2      M    M
  5250    3.3  37.9   325    4    2   5.2   2.9    5.3  41.6    -8.6      M    M
  5000    3.8  38.8   310    3    2  11.6   6.4    5.2  41.4    -8.8      M    M

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

           04/29/2017 at 0900 MDT          |       04/29/2017 at 1200 MDT
                                           |
K index... +12.4  LI... +4.4               | K index... +13.9  LI... +3.5
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 -54.3 -65.7  300  13  7   2.2   1.2 | -54.0 -65.2  300  17  9   1.8   1.0
 45000 -50.8 -59.4  335  16  8   2.2   1.2 | -51.3 -60.3  325  13  7   1.8   1.0
 40000 -48.5 -55.3  330  16  8   1.5   0.8 | -48.6 -55.5  350  20 10   1.8   1.0
 38000 -47.9 -54.2  320  13  7  -0.5  -0.3 | -47.7 -53.9  350  21 11   0.3   0.2
 36000 -48.2 -54.8  255   5  3  -0.5  -0.3 | -47.5 -53.5  340  16  8   0.3   0.2
 34000 -48.6 -55.5  185  13  7  -0.6  -0.3 | -47.3 -53.1  325  13  7   0.2   0.1
 32000 -48.2 -54.8  170  29 15   0.9   0.5 | -47.7 -53.9  200   8  4  -0.7  -0.4
 30000 -47.6 -53.7  165  50 26   2.0   1.1 | -48.1 -54.6  175  27 14  -0.5  -0.3
 29000 -46.2 -51.2  165  47 24   5.2   2.8 | -47.0 -52.6  170  31 16   4.9   2.7
 28000 -44.6 -48.3  165  43 22   5.2   2.8 | -45.6 -50.1  165  34 17   4.8   2.7
 27000 -43.1 -45.6  160  38 20   5.2   2.9 | -44.1 -47.4  160  36 19   4.9   2.7
 26000 -41.5 -42.7  155  32 17   5.6   3.1 | -41.8 -43.2  150  32 17   7.6   4.2
 25000 -39.8 -39.6  135  25 13   5.6   3.1 | -39.5 -39.1  135  25 13   7.7   4.2
 24000 -38.1 -36.6  110  23 12   5.7   3.1 | -37.2 -35.0  105  20 11   7.7   4.2
 23000 -36.0 -32.8  090  22 11   8.4   4.6 | -34.9 -30.8  090  19 10   7.8   4.3
 22000 -33.5 -28.3  080  16  8   8.4   4.6 | -32.6 -26.7  080  18  9   7.8   4.3
 21000 -31.0 -23.8  065  11  6   8.4   4.6 | -30.3 -22.5  065  17  9   7.8   4.3
 20000 -28.5 -19.3  050  12  6   8.5   4.7 | -27.8 -18.0  060  19 10   8.5   4.7
 19500 -27.2 -17.0  050  13  7   8.5   4.7 | -26.5 -15.7  060  20 10   8.5   4.7
 19000 -25.9 -14.6  045  14  7   8.5   4.7 | -25.3 -13.5  060  21 11   8.6   4.7
 18500 -24.7 -12.5  045  15  8   8.6   4.7 | -24.0 -11.2  060  22 11   8.6   4.7
 18000 -23.5 -10.3  045  16  8   7.4   4.0 | -22.8  -9.0  060  22 11   8.0   4.4
 17500 -22.4  -8.3  045  17  9   7.2   4.0 | -21.6  -6.9  060  22 11   8.0   4.4
 17000 -21.3  -6.3  050  18  9   7.0   3.8 | -20.4  -4.7  055  22 11   7.8   4.3
 16500 -20.4  -4.7  050  17  9   6.6   3.6 | -19.3  -2.7  055  21 11   7.7   4.2
 16000 -19.4  -2.9  050  17  9   6.6   3.6 | -18.1  -0.6  055  20 11   7.3   4.0
 15500 -18.4  -1.1  050  16  8   7.4   4.0 | -17.1   1.2  055  20 10   6.5   3.6
 15000 -17.3   0.9  050  16  8   7.3   4.0 | -16.2   2.8  055  19 10   6.5   3.6
 14500 -15.6   3.9  055  16  8   7.4   4.1 | -15.2   4.6  055  19 10   6.7   3.7
 14000 -14.5   5.9  055  17  9   7.2   3.9 | -14.2   6.4  055  19 10   6.7   3.7
 13500 -13.5   7.7  055  17  9   6.3   3.5 | -13.2   8.2  055  18  9   6.6   3.6
 13000 -12.5   9.5  060  18  9   6.4   3.5 | -12.3   9.9  055  18  9   6.7   3.7
 12500 -11.6  11.1  065  18  9   6.5   3.6 | -11.0  12.2  050  18  9   5.6   3.1
 12000 -10.6  12.9  065  19 10   6.4   3.5 | -10.1  13.8  050  18  9   4.9   2.7
 11500  -9.7  14.5  070  20 10   5.9   3.2 |  -9.6  14.7  050  17  9   3.7   2.0
 11000  -8.8  16.2  070  20 10   5.7   3.1 |  -9.0  15.8  045  16  8   3.5   1.9
 10500  -8.1  17.4  075  20 10   4.8   2.6 |  -8.5  16.7  045  15  8   2.8   1.6
 10250  -7.7  18.1  075  20 10   4.1   2.2 |  -8.3  17.1  040  15  8   5.8   3.2
 10000  -7.4  18.7  075  20 11   7.1   3.8 |  -7.7  18.1  035  14  7   8.6   4.7
  9750  -6.7  19.9  075  20 10   7.9   4.3 |  -7.1  19.2  035  13  7   7.7   4.3
  9500  -6.3  20.7  075  20 11   5.8   3.2 |  -6.5  20.3  035  12  6   8.1   4.4
  9250  -5.8  21.6  075  21 11   6.4   3.5 |  -5.9  21.4  035  12  6   7.6   4.2
  9000  -5.3  22.5  075  21 11   5.5   3.0 |  -5.3  22.5  040  11  6   8.6   4.7
  8750  -5.0  23.0  080  21 11   4.9   2.7 |  -4.6  23.7  040  11  6  10.2   5.6
  8500  -4.6  23.7  080  21 11   5.1   2.8 |  -3.8  25.2  040  11  5  10.3   5.7
  8250  -4.2  24.4  080  21 11   4.9   2.7 |  -3.0  26.6  040  10  5  10.2   5.6
  8000  -3.9  25.0  075  20 10   4.3   2.4 |  -2.3  27.9  040  10  5  10.0   5.5
  7750  -3.6  25.5  070  19 10   4.0   2.2 |  -1.6  29.1  040  10  5  10.0   5.5
  7500  -3.3  26.1  065  17  9   3.8   2.1 |  -0.8  30.6  040  10  5  10.1   5.5
  7250  -3.0  26.6  060  16  8   7.2   3.9 |  -0.0  32.0  040   9  5  10.4   5.7
  7000  -2.3  27.9  060  15  8  10.0   5.5 |   0.7  33.3  045   9  5  10.5   5.7
  6750  -1.6  29.1  060  15  8   9.1   5.0 |   1.5  34.7  045   9  5   9.8   5.4
  6500  -0.9  30.4  060  14  7  10.2   5.6 |   2.2  36.0  045   9  4  10.5   5.7
  6250  -0.1  31.8  060  14  7  11.5   6.3 |   3.1  37.6  045   8  4  11.6   6.4
  6000   0.8  33.4  060  13  7  11.1   6.1 |   3.9  39.0  045   8  4  10.7   5.9
  5750   1.6  34.9  055  13  7  10.6   5.8 |   4.8  40.6  045   7  4  12.8   7.0
  5500   2.4  36.3  055  12  6  11.2   6.2 |   5.9  42.6  045   7  4  16.4   9.0
  5250   3.3  37.9  055  11  6  12.5   6.8 |   7.1  44.8  045   7  4  16.4   9.0
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/29/2017 at 1500 MDT          |       04/29/2017 at 1800 MDT
                                           |
K index... +11.1  LI... +2.4               | K index... +8.1  LI... +1.9
CAPE... +2.0  CIN... 0.0                   | CAPE... +1.3  CIN... -0.6
                                           |
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 -54.1 -65.4  310  21 11   1.2   0.6 | -54.9 -66.8  325  23 12   1.1   0.6
 45000 -52.4 -62.3  325  23 12   1.2   0.7 | -53.2 -63.8  340  30 16   1.2   0.6
 40000 -49.5 -57.1  350  24 12   1.8   1.0 | -50.4 -58.7  345  34 18   1.8   1.0
 38000 -48.8 -55.8  355  26 13   0.5   0.3 | -49.7 -57.5  350  36 18   0.6   0.3
 36000 -48.5 -55.3  355  27 14   0.5   0.3 | -49.3 -56.7  355  37 19   0.6   0.3
 34000 -48.2 -54.8  355  28 14   0.3   0.2 | -49.0 -56.2  360  39 20   0.5   0.3
 32000 -48.3 -54.9  355  11  6  -0.2  -0.1 | -48.8 -55.8  005  21 11   0.3   0.2
 30000 -48.4 -55.1  170   6  3   1.3   0.7 | -48.6 -55.5  060   4  2   3.5   1.9
 29000 -46.9 -52.4  155  11  6   5.7   3.1 | -46.5 -51.7  120   6  3   7.1   3.9
 28000 -45.2 -49.4  145  17  9   5.7   3.1 | -44.4 -47.9  140  11  6   7.1   3.9
 27000 -43.0 -45.4  140  24 12   5.4   3.0 | -41.7 -43.1  145  17  9   7.1   3.9
 26000 -40.8 -41.4  135  22 11   8.2   4.5 | -39.3 -38.7  145  13  7   8.2   4.5
 25000 -38.4 -37.1  130  16  8   8.1   4.5 | -36.9 -34.4  140   7  4   8.2   4.5
 24000 -35.9 -32.6  115  12  6   8.2   4.5 | -34.4 -29.9  110   2  1   8.4   4.6
 23000 -33.6 -28.5  090   9  4   7.6   4.2 | -32.3 -26.1  010   4  2   6.7   3.7
 22000 -31.3 -24.3  050   8  4   7.6   4.2 | -30.3 -22.5  360   8  4   6.7   3.7
 21000 -29.1 -20.4  020  11  6   7.7   4.2 | -28.3 -18.9  360  13  7   7.2   4.0
 20000 -26.7 -16.1  025  14  7   8.1   4.5 | -25.9 -14.6  005  15  8   8.1   4.4
 19500 -25.4 -13.7  030  15  8   8.1   4.5 | -24.6 -12.3  010  16  8   8.1   4.4
 19000 -24.2 -11.6  030  17  9   8.1   4.5 | -23.4 -10.1  010  17  9   8.1   4.4
 18500 -23.0  -9.4  035  18  9   8.2   4.5 | -22.2  -8.0  015  18  9   8.1   4.5
 18000 -21.8  -7.2  035  18  9   8.4   4.6 | -21.0  -5.8  015  19 10   8.4   4.6
 17500 -20.5  -4.9  035  18  9   8.4   4.6 | -19.7  -3.5  015  20 10   8.4   4.6
 17000 -19.3  -2.7  030  18  9   8.2   4.5 | -18.5  -1.3  015  20 10   8.0   4.4
 16500 -18.1  -0.6  030  19 10   8.2   4.5 | -17.3   0.9  015  21 11   8.0   4.4
 16000 -16.9   1.6  030  20 10   7.5   4.1 | -16.2   2.8  015  21 11   7.3   4.0
 15500 -15.9   3.4  030  20 10   6.7   3.7 | -15.2   4.6  010  21 11   6.7   3.7
 15000 -14.9   5.2  025  19 10   6.4   3.5 | -14.2   6.4  010  21 11   6.2   3.4
 14500 -14.1   6.6  025  19 10   4.9   2.7 | -13.4   7.9  005  20 10   4.5   2.5
 14000 -13.3   8.1  025  19 10   5.0   2.8 | -12.8   9.0  360  19 10   4.6   2.5
 13500 -12.7   9.1  020  18  9   4.0   2.2 | -12.1  10.2  360  19 10   5.2   2.9
 13000 -11.8  10.8  015  18  9   5.3   2.9 | -11.0  12.2  360  20 10   6.0   3.3
 12500 -10.9  12.4  015  17  9   6.5   3.6 | -10.0  14.0  005  20 10   6.6   3.6
 12000 -10.0  14.0  010  16  8   7.7   4.2 |  -9.1  15.6  010  20 10   7.9   4.3
 11500  -8.6  16.5  010  15  8   8.8   4.8 |  -7.8  18.0  010  22 11   8.8   4.9
 11000  -7.3  18.9  010  14  7   8.6   4.7 |  -6.5  20.3  010  23 12   8.2   4.5
 10500  -6.1  21.0  010  14  7   7.6   4.2 |  -5.3  22.5  015  23 12   6.8   3.7
 10250  -5.5  22.1  010  14  7  11.0   6.1 |  -4.7  23.5  015  23 12  11.9   6.5
 10000  -4.5  23.9  015  13  7  11.9   6.5 |  -3.6  25.5  015  23 12  13.2   7.2
  9750  -3.8  25.2  015  13  7   9.1   5.0 |  -2.9  26.8  015  23 12   8.9   4.9
  9500  -3.0  26.6  015  13  7   9.9   5.4 |  -2.1  28.2  015  23 12  10.4   5.7
  9250  -2.3  27.9  015  12  6   9.5   5.2 |  -1.4  29.5  015  23 12   8.7   4.8
  9000  -1.6  29.1  015  12  6   9.8   5.4 |  -0.8  30.6  015  23 12   9.1   5.0
  8750  -0.9  30.4  015  12  6  10.3   5.6 |  -0.0  32.0  015  22 12  10.7   5.9
  8500  -0.1  31.8  015  12  6  10.0   5.5 |   0.8  33.4  015  22 12  10.1   5.6
  8250   0.7  33.3  015  12  6  10.6   5.8 |   1.5  34.7  015  22 11  10.8   5.9
  8000   1.5  34.7  015  11  6  10.5   5.8 |   2.4  36.3  015  22 11  10.6   5.8
  7750   2.2  36.0  015  11  6   9.5   5.2 |   3.1  37.6  015  22 11   9.4   5.1
  7500   2.9  37.2  015  11  6   9.7   5.3 |   3.8  38.8  015  22 11   9.4   5.2
  7250   3.7  38.7  015  11  5  10.7   5.9 |   4.5  40.1  015  22 11  10.0   5.5
  7000   4.5  40.1  015  10  5  10.8   5.9 |   5.3  41.5  015  22 11  10.1   5.5
  6750   5.2  41.4  015  10  5   8.9   4.9 |   6.0  42.8  015  21 11   8.9   4.9
  6500   5.9  42.6  015  10  5  10.2   5.6 |   6.7  44.1  015  21 11  10.2   5.6
  6250   6.8  44.2  015   9  5  12.5   6.9 |   7.5  45.5  015  20 10  11.9   6.5
  6000   7.7  45.9  015   9  5  11.1   6.1 |   8.4  47.1  015  19 10  11.0   6.1
  5750   8.5  47.3  015   8  4  12.3   6.8 |   9.2  48.6  015  18  9  10.6   5.8
  5500   9.6  49.3  015   8  4  16.5   9.0 |  10.0  50.0  015  17  9  11.1   6.1
  5250  10.9  51.6  015   9  4  18.2  10.0 |  10.8  51.4  010  17  9  11.9   6.5
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

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

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

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

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

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

DEFINITIONS:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

042613


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