Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
000
UXUS97 KBOU 190112
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1911 MDT Friday, July 18, 2014

This forecast is for Saturday, July 19, 2014:

If the trigger temperature of 85.5 F/29.7 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1413 ft/min (7.2 m/s)
   Maximum height of thermals.................. 19895 ft MSL (14608 ft AGL)

Forecast maximum temperature................... 94.0 F/34.9 C
Time of trigger temperature.................... 1015 MDT
Time of overdevelopment........................ 1800 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 17206 ft MSL (11919 ft AGL)
Thermal soaring outlook for Sunday 07/20....... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 37777 ft MSL (32490 ft AGL)
Wave soaring outlook for Sunday 07/20.......... Poor

Remarks... None

Sunrise/Sunset.................... 05:47:14 / 20:24:31 MDT
Total possible sunshine........... 14 hr 37 min 17 sec (877 min 17 sec)
Altitude of sun at 13:05:45 MDT... 70.95 degrees

Upper air data from numerical model forecast valid on 07/19/2014 at 0600 MDT

Freezing level.................. 15603 ft MSL (10316 ft AGL)
Convective condensation level... 17081 ft MSL (11794 ft AGL)
Lifted condensation level....... 18468 ft MSL (13180 ft AGL)
Lifted index.................... -2.6
K index......................... +24.6

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  -63.7 -82.7   285   35   18  -0.1  -0.0      M     M       M      M    M
 45000  -61.5 -78.7   280   54   28   5.1   2.8      M     M       M      M    M
 40000  -53.7 -64.7   275   61   32   6.8   3.7      M     M       M      M    M
 38000  -49.6 -57.3   280   57   30   6.9   3.8      M     M       M      M    M
 36000  -45.5 -49.9   285   53   28   6.8   3.7      M     M       M      M    M
 34000  -41.2 -42.2   285   46   24   7.2   4.0      M     M       M      M    M
 32000  -36.8 -34.2   295   37   19   7.2   3.9      M     M       M      M    M
 30000  -32.1 -25.8   295   30   16   6.9   3.8   42.9 109.3     6.5      M    M
 29000  -30.1 -22.2   295   27   14   6.9   3.8   41.9 107.4     5.7      M    M
 28000  -28.0 -18.4   295   25   13   7.7   4.2   40.9 105.7     5.0      M    M
 27000  -25.6 -14.1   300   24   12   7.9   4.3   40.1 104.2     4.4      M    M
 26000  -23.3  -9.9   300   24   12   7.9   4.3   39.4 102.9     3.9      M    M
 25000  -20.9  -5.6   300   23   12   8.0   4.4   38.8 101.9     3.5      M    M
 24000  -18.4  -1.1   300   21   11   8.5   4.7   38.3 100.9     3.0      M    M
 23000  -15.8   3.6   305   19   10   8.5   4.7   37.8 100.0     2.7      M    M
 22000  -13.3   8.1   305   16    8   7.6   4.2   37.4  99.4     2.4      M    M
 21000  -11.4  11.5   310   17    9   6.1   3.4   36.1  97.0     1.3      M    M
 20000   -9.6  14.7   315   17    9   6.2   3.4   34.8  94.7     0.2      M    M
 19500   -8.7  16.3   320   17    9   6.3   3.5   34.3  93.7    -0.4   1385  7.0
 19000   -7.9  17.8   320   18    9   5.9   3.3   33.7  92.6    -0.9   1345  6.8
 18500   -7.1  19.2   315   17    9   6.1   3.4   33.0  91.4    -1.6   1305  6.6
 18000   -6.2  20.8   315   17    9   6.8   3.7   32.4  90.3    -2.2   1266  6.4
 17500   -5.2  22.6   315   16    8   7.6   4.2   32.0  89.6    -2.7   1219  6.2
 17000   -4.1  24.6   310   15    8   7.5   4.1   31.6  89.0    -3.1   1172  6.0
 16500   -2.9  26.8   310   14    7   9.7   5.3   31.5  88.6    -3.3   1120  5.7
 16000   -1.5  29.3   310   14    7   9.5   5.2   31.4  88.5    -3.4   1063  5.4
 15500    0.6  33.1   310   13    7   9.4   5.1   31.3  88.4    -3.5    978  5.0
 15000    2.0  35.6   310   12    6   9.3   5.1   31.3  88.3    -3.6    922  4.7
 14500    3.4  38.1   310   12    6   9.8   5.4   31.3  88.3    -3.7    865  4.4
 14000    4.9  40.8   310   11    6   9.9   5.4   31.3  88.3    -3.7    806  4.1
 13500    6.4  43.5   310   11    6   9.6   5.2   31.3  88.3    -3.7    747  3.8
 13000    7.8  46.0   310   11    6   9.4   5.2   31.2  88.2    -3.8    690  3.5
 12500    9.2  48.6   305   11    6   9.5   5.2   31.2  88.1    -3.8    633  3.2
 12000   10.6  51.1   305   11    6   9.5   5.2   31.1  88.0    -3.9    576  2.9
 11500   12.0  53.6   305   12    6   9.4   5.2   31.1  88.0    -4.0    519  2.6
 11000   13.4  56.1   305   12    6   9.1   5.0   31.0  87.9    -4.0    462  2.3
 10500   14.8  58.6   300   12    6   4.9   2.7   31.0  87.8    -4.1    405  2.1
 10250   15.0  59.0   300   12    6   6.0   3.3   30.4  86.8    -4.6    391  2.0
 10000   15.9  60.6   300   12    6  12.3   6.8   30.5  87.0    -4.5    359  1.8
  9750   16.7  62.1   295   12    6  11.4   6.2   30.7  87.2    -4.5    327  1.7
  9500   17.5  63.5   295   12    6   8.9   4.9   30.8  87.4    -4.4    295  1.5
  9250   18.0  64.4   290   11    6   6.3   3.4   30.5  86.9    -4.6    273  1.4
  9000   18.6  65.5   285   11    6   8.6   4.7   30.4  86.6    -4.8    249  1.3
  8750   19.2  66.6   280   11    6   9.3   5.1   30.3  86.5    -4.9    221  1.1
  8500   19.9  67.8   275   11    5   8.8   4.8   30.3  86.5    -4.9    193  1.0
  8250   20.5  68.9   270   10    5   8.6   4.7   30.2  86.3    -5.0    167  0.8
  8000   21.2  70.2   265   10    5   8.3   4.6   30.1  86.2    -5.2    141  0.7
  7750   21.8  71.2   260   10    5   8.0   4.4   30.0  85.9    -5.3    116  0.6
  7500   22.3  72.1   255   10    5   8.0   4.4   29.8  85.7    -5.5     91  0.5
  7250   22.9  73.2   255   10    5   7.7   4.2   29.7  85.4    -5.6     66  0.3
  7000   23.5  74.3   255    9    5   8.6   4.7   29.5  85.2    -5.8     42  0.2
  6750   24.1  75.4   255   10    5   5.9   3.2   29.4  84.9    -6.0     17  0.1
  6500   24.2  75.6   255   10    5  -1.7  -0.9   28.8  83.9    -6.6      5  0.0
  6250   23.8  74.8   250   10    5  -9.5  -5.2   27.7  81.8    -7.8     11  0.1
  6000   23.3  73.9   250   10    5   6.5   3.6   26.5  79.7    -9.0     17  0.1
  5750   23.9  75.0   250   10    5  -9.9  -5.4   26.4  79.5    -9.1      M    M
  5500   20.2  68.4   235    8    4 -86.4 -47.4   22.1  71.8   -13.6     97  0.5

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

           07/19/2014 at 0900 MDT          |       07/19/2014 at 1200 MDT
                                           |
K index... +24.1  LI... -0.2               | K index... +15.1  LI... -0.3
CAPE... +100.9  CIN... -95.1               | CAPE... +105.6  CIN... -26.2
                                           |
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  285  30 16   0.3   0.2 | -63.3 -81.9  280  33 17   0.5   0.3
 45000 -60.6 -77.1  285  51 26   4.7   2.6 | -60.6 -77.1  280  49 25   4.9   2.7
 40000 -53.4 -64.1  280  60 31   6.0   3.3 | -53.1 -63.6  280  57 29   5.8   3.2
 38000 -49.8 -57.6  280  55 28   6.0   3.3 | -49.6 -57.3  280  51 26   5.8   3.2
 36000 -46.2 -51.2  285  51 26   5.9   3.3 | -46.1 -51.0  280  46 24   5.7   3.1
 34000 -41.9 -43.4  285  44 23   7.3   4.0 | -41.8 -43.2  285  40 20   7.4   4.1
 32000 -37.0 -34.6  290  35 18   7.4   4.0 | -36.8 -34.2  290  33 17   7.5   4.1
 30000 -32.9 -27.2  290  29 15   6.8   3.7 | -32.4 -26.3  290  29 15   7.3   4.0
 29000 -30.8 -23.4  290  26 14   6.8   3.7 | -30.2 -22.4  290  27 14   7.3   4.0
 28000 -28.8 -19.8  290  23 12   8.0   4.4 | -28.1 -18.6  290  25 13   7.5   4.1
 27000 -26.3 -15.3  290  22 11   8.3   4.5 | -25.8 -14.4  290  24 12   7.6   4.2
 26000 -23.8 -10.8  290  20 10   8.3   4.5 | -23.5 -10.3  290  22 12   7.6   4.2
 25000 -21.3  -6.3  290  18  9   8.2   4.5 | -21.2  -6.2  285  21 11   7.8   4.3
 24000 -18.9  -2.0  295  17  9   7.9   4.3 | -18.8  -1.8  290  19 10   8.1   4.4
 23000 -16.6   2.1  300  16  8   7.9   4.3 | -16.4   2.5  290  17  9   8.1   4.4
 22000 -14.2   6.4  310  15  8   7.6   4.1 | -14.0   6.8  295  16  8   7.6   4.2
 21000 -12.1  10.2  310  16  8   7.0   3.9 | -11.9  10.6  295  16  8   7.0   3.8
 20000 -10.0  14.0  310  17  9   7.1   3.9 |  -9.8  14.4  300  16  8   7.0   3.8
 19500  -9.0  15.8  310  17  9   7.2   3.9 |  -8.8  16.2  300  16  8   7.0   3.8
 19000  -8.0  17.6  310  18  9   6.6   3.6 |  -7.7  18.1  300  16  8   7.6   4.1
 18500  -7.1  19.2  305  18  9   6.7   3.7 |  -6.6  20.1  300  17  9   7.5   4.1
 18000  -6.1  21.0  305  18  9   7.1   3.9 |  -5.5  22.1  300  17  9   7.5   4.1
 17500  -5.1  22.8  305  17  9   7.4   4.1 |  -4.4  24.1  305  17  9   7.5   4.1
 17000  -4.0  24.8  305  16  8   7.4   4.1 |  -3.3  26.1  310  17  9   7.5   4.1
 16500  -2.8  27.0  305  15  8   9.4   5.1 |  -2.1  28.2  310  17  9   8.7   4.8
 16000  -0.8  30.6  305  14  7   9.3   5.1 |  -0.2  31.6  315  16  8   8.7   4.8
 15500   0.6  33.1  305  13  7   9.7   5.3 |   1.1  34.0  315  15  8   9.0   4.9
 15000   2.0  35.6  305  13  7   9.7   5.3 |   2.5  36.5  315  14  7   9.0   4.9
 14500   3.5  38.3  305  13  7   9.7   5.3 |   3.8  38.8  315  13  7   9.5   5.2
 14000   4.9  40.8  310  12  6   9.7   5.3 |   5.2  41.4  320  12  6   9.5   5.2
 13500   6.3  43.3  310  12  6   9.8   5.4 |   6.6  43.9  320  11  6   9.0   4.9
 13000   7.8  46.0  310  12  6   9.8   5.4 |   7.9  46.2  320  10  5   8.9   4.9
 12500   9.2  48.6  310  12  6   9.5   5.2 |   9.2  48.6  325   9  5   9.3   5.1
 12000  10.6  51.1  310  13  6   9.3   5.1 |  10.6  51.1  330   8  4   9.4   5.2
 11500  12.0  53.6  310  13  7   9.2   5.1 |  12.0  53.6  335   8  4   9.3   5.1
 11000  13.4  56.1  310  14  7   8.9   4.9 |  13.4  56.1  335   7  4   8.9   4.9
 10500  14.8  58.6  310  14  7   4.3   2.4 |  14.7  58.5  340   7  4   4.8   2.6
 10250  14.9  58.8  310  14  7   5.5   3.0 |  14.9  58.8  340   7  4   5.9   3.2
 10000  15.7  60.3  310  14  7  12.3   6.7 |  15.7  60.3  340   6  3  12.1   6.7
  9750  16.5  61.7  305  13  7  11.2   6.2 |  16.5  61.7  335   6  3  11.1   6.1
  9500  17.3  63.1  305  13  7   8.7   4.8 |  17.2  63.0  335   5  3   9.2   5.1
  9250  17.9  64.2  300  13  7   6.7   3.7 |  17.8  64.0  330   5  3   8.2   4.5
  9000  18.5  65.3  300  12  6   9.6   5.3 |  18.5  65.3  330   5  3  10.8   5.9
  8750  19.2  66.6  295  12  6  10.4   5.7 |  19.3  66.7  330   5  3  11.1   6.1
  8500  20.0  68.0  295  11  6   9.1   5.0 |  20.1  68.2  325   5  2  10.2   5.6
  8250  20.6  69.1  290  10  5   8.0   4.4 |  20.8  69.4  325   5  2   9.3   5.1
  8000  21.2  70.2  285  10  5   8.4   4.6 |  21.5  70.7  325   5  2  10.0   5.5
  7750  21.8  71.2  280   9  5   8.4   4.6 |  22.3  72.1  325   5  2  10.3   5.7
  7500  22.4  72.3  275   9  5   8.3   4.6 |  23.1  73.6  325   5  2  10.2   5.6
  7250  23.0  73.4  280   9  4   8.0   4.4 |  23.8  74.8  320   5  2  10.2   5.6
  7000  23.6  74.5  285   8  4   9.0   4.9 |  24.6  76.3  320   5  2  10.3   5.6
  6750  24.3  75.7  290   8  4   7.6   4.2 |  25.4  77.7  320   5  2  10.7   5.9
  6500  24.6  76.3  290   8  4   2.7   1.5 |  26.2  79.2  320   5  2  10.7   5.9
  6250  24.7  76.5  290   7  4   2.9   1.6 |  27.0  80.6  320   5  2  11.3   6.2
  6000  24.8  76.6  290   7  3  -2.3  -1.3 |  27.8  82.0  320   5  2   9.1   5.0
  5750  24.5  76.1  285   6  3   0.6   0.3 |  28.5  83.3  320   5  2  14.5   7.9
  5500  25.2  77.4  275   5  2  22.0  12.1 |  30.2  86.4  320   5  2  29.5  16.2

           07/19/2014 at 1500 MDT          |       07/19/2014 at 1800 MDT
                                           |
K index... +21.9  LI... -0.1               | K index... +22.7  LI... -0.5
CAPE... +60.0  CIN... -28.8                | CAPE... +80.0  CIN... -27.4
                                           |
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 -63.5 -82.3  280  35 18   0.9   0.5 | -63.6 -82.5  285  32 16   1.1   0.6
 45000 -60.4 -76.7  280  50 26   4.8   2.6 | -60.3 -76.5  285  47 24   4.7   2.6
 40000 -53.0 -63.4  280  57 29   6.1   3.3 | -52.6 -62.7  280  55 28   6.4   3.5
 38000 -49.3 -56.7  280  52 27   6.1   3.3 | -48.7 -55.7  280  51 26   6.4   3.5
 36000 -45.6 -50.1  280  47 24   6.0   3.3 | -44.9 -48.8  285  48 24   6.5   3.6
 34000 -40.8 -41.4  285  40 20   7.3   4.0 | -40.4 -40.7  285  41 21   7.6   4.2
 32000 -36.4 -33.5  290  32 17   7.4   4.1 | -35.9 -32.6  290  35 18   7.5   4.1
 30000 -31.9 -25.4  290  28 14   7.5   4.1 | -31.4 -24.5  290  31 16   7.4   4.1
 29000 -29.7 -21.5  295  26 13   7.5   4.1 | -29.2 -20.6  295  29 15   7.4   4.1
 28000 -27.4 -17.3  295  25 13   7.2   4.0 | -26.4 -15.5  295  26 14   7.5   4.1
 27000 -25.3 -13.5  295  24 12   7.2   3.9 | -24.2 -11.6  300  25 13   7.5   4.1
 26000 -23.1  -9.6  295  24 12   7.2   3.9 | -21.9  -7.4  300  23 12   7.5   4.1
 25000 -21.0  -5.8  295  24 12   7.5   4.1 | -19.7  -3.5  305  22 11   7.3   4.0
 24000 -18.5  -1.3  295  22 11   8.2   4.5 | -17.6   0.3  305  22 11   7.1   3.9
 23000 -16.1   3.0  295  20 10   8.2   4.5 | -15.5   4.1  300  22 11   7.1   3.9
 22000 -13.6   7.5  290  18  9   7.6   4.2 | -13.4   7.9  300  22 11   7.2   4.0
 21000 -11.6  11.1  295  19 10   7.0   3.8 | -11.3  11.7  300  22 11   7.4   4.0
 20000  -9.6  14.7  295  19 10   7.0   3.9 |  -9.1  15.6  295  22 12   7.5   4.1
 19500  -8.5  16.7  295  19 10   7.1   3.9 |  -8.1  17.4  295  23 12   7.7   4.3
 19000  -7.5  18.5  295  20 10   8.0   4.4 |  -6.9  19.6  295  22 11   8.8   4.8
 18500  -6.3  20.7  295  20 10   8.0   4.4 |  -5.6  21.9  295  21 11   8.8   4.8
 18000  -5.2  22.6  295  20 10   8.4   4.6 |  -4.4  24.1  295  20 10   8.7   4.8
 17500  -3.9  25.0  295  19 10   8.7   4.7 |  -3.1  26.4  295  18  9   8.7   4.7
 17000  -2.7  27.1  295  18 10   8.7   4.8 |  -1.9  28.6  295  16  8   8.8   4.8
 16500  -0.7  30.7  295  17  9   9.2   5.1 |  -0.6  30.9  295  15  7   9.1   5.0
 16000   0.7  33.3  295  15  8   9.2   5.0 |   0.8  33.4  300  13  7   9.1   5.0
 15500   2.0  35.6  295  14  7   8.9   4.9 |   2.1  35.8  300  11  6   9.0   4.9
 15000   3.3  37.9  295  12  6   8.9   4.9 |   3.4  38.1  300  10  5   9.0   4.9
 14500   4.7  40.5  295  11  6   9.4   5.2 |   4.8  40.6  300   8  4   9.2   5.1
 14000   6.1  43.0  295  10  5   9.4   5.1 |   6.9  44.4  300   7  3   9.5   5.2
 13500   7.5  45.5  295   8  4   9.2   5.1 |   8.3  46.9  300   6  3   9.0   5.0
 13000   8.9  48.0  295   7  3   9.2   5.0 |   9.6  49.3  295   4  2   9.0   4.9
 12500  10.2  50.4  295   6  3   9.2   5.0 |  10.9  51.6  290   3  2   9.1   5.0
 12000  11.6  52.9  290   5  3   9.2   5.0 |  12.3  54.1  275   3  1   9.2   5.0
 11500  13.0  55.4  285   4  2   9.0   4.9 |  13.7  56.7  260   2  1   9.0   5.0
 11000  14.3  57.7  275   3  2   8.5   4.7 |  15.0  59.0  245   3  1   8.7   4.8
 10500  15.6  60.1  260   3  1   4.8   2.6 |  16.3  61.3  235   3  2   5.4   3.0
 10250  15.8  60.4  260   3  1   6.3   3.5 |  16.6  61.9  235   3  2   7.0   3.8
 10000  16.6  61.9  255   3  1  12.3   6.8 |  17.5  63.5  235   3  2  12.3   6.7
  9750  17.5  63.5  255   3  1  11.3   6.2 |  18.3  64.9  235   3  2  11.7   6.4
  9500  18.3  64.9  250   3  1   9.6   5.3 |  19.1  66.4  235   4  2   8.5   4.7
  9250  18.9  66.0  250   3  1   8.5   4.7 |  19.6  67.3  235   4  2   7.2   3.9
  9000  19.6  67.3  250   3  1  10.6   5.8 |  20.3  68.5  235   4  2  10.6   5.8
  8750  20.4  68.7  250   3  1  10.7   5.9 |  21.1  70.0  240   4  2  10.4   5.7
  8500  21.2  70.2  250   3  1  10.2   5.6 |  21.8  71.2  240   4  2  10.1   5.6
  8250  22.0  71.6  250   3  1   9.8   5.4 |  22.6  72.7  240   4  2   9.8   5.4
  8000  22.7  72.9  250   3  1  10.0   5.5 |  23.3  73.9  245   4  2   9.9   5.4
  7750  23.5  74.3  255   3  1  10.0   5.5 |  24.0  75.2  245   4  2   9.9   5.4
  7500  24.2  75.6  255   3  1  10.2   5.6 |  24.8  76.6  245   4  2  10.0   5.5
  7250  25.0  77.0  255   3  2  10.2   5.6 |  25.5  77.9  245   4  2  10.2   5.6
  7000  25.8  78.4  255   3  2  10.3   5.6 |  26.3  79.3  250   4  2   9.9   5.5
  6750  26.5  79.7  255   3  2  10.6   5.8 |  27.0  80.6  250   4  2   9.8   5.4
  6500  27.3  81.1  255   3  2  10.6   5.8 |  27.8  82.0  250   4  2  10.0   5.5
  6250  28.1  82.6  255   3  2  11.3   6.2 |  28.5  83.3  250   4  2  10.4   5.7
  6000  28.9  84.0  255   3  2   8.8   4.8 |  29.3  84.7  255   4  2   9.5   5.2
  5750  29.6  85.3  250   3  2  14.4   7.9 |  30.0  86.0  255   4  2  12.4   6.8
  5500  31.3  88.3  255   3  2  31.0  17.0 |  31.2  88.2  255   4  2  19.8  10.9
________________________________________________________________________________

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 near the old Stapleton
Airport site in Denver, Colorado at

                   North Latitude:  39 deg 46 min 5.016 sec
                   West Longitude: 104 deg 52 min 9.984 sec
                   Elevation: 5285 feet (1611 meters)

and may not be representative of other areas along the Front Range of the
Colorado Rocky Mountains.  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


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.