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236
UXUS97 KBOU 231232
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0632 MDT Wednesday, April 23, 2014

This forecast is for Wednesday, April 23, 2014:

If the trigger temperature of 68.4 F/20.2 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 5709 ft MSL (424 ft AGL)

Forecast maximum temperature................... 66.0 F/19.3 C
Time of trigger temperature.................... None
Time of overdevelopment........................ 1500 MDT
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 5313 ft MSL (27 ft AGL)
Thermal soaring outlook for Thursday 04/24..... Excellent

Wave Soaring Index............................. Good
Wave Soaring Index trend (to 1800 MDT)......... Little change
Height of stable layer (12-18K ft MSL)......... 15623 ft MSL (10338 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 17100 ft MSL (11815 ft AGL)
Wave soaring outlook for Thursday 04/24........ Good

Remarks...

Sunrise/Sunset.................... 06:10:29 / 19:44:49 MDT
Total possible sunshine........... 13 hr 34 min 19 sec (814 min 19 sec)
Altitude of sun at 12:57:49 MDT... 62.92 degrees

Upper air data from rawinsonde observation taken on 04/23/2014 at 0600 MDT

Freezing level.................. 12381 ft MSL (7096 ft AGL)
Convective condensation level... 17352 ft MSL (12067 ft AGL)
Lifted condensation level....... 14887 ft MSL (9602 ft AGL)
Lifted index.................... +3.7
K index......................... +11.1

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  -56.3 -69.3   250   36   18   7.5   4.1  105.3 221.6    49.5      M    M
 45000  -60.6 -77.1   230   66   34   3.8   2.1   72.1 161.7    32.8      M    M
 40000  -62.6 -80.7   210   71   37   6.9   3.8   45.9 114.6    17.8      M    M
 38000  -60.4 -76.7   210   73   38   3.1   1.7   40.4 104.7    14.6      M    M
 36000  -56.1 -69.0   205   71   36   8.8   4.8   38.0 100.5    13.4      M    M
 34000  -50.2 -58.4   200   67   34   8.7   4.8   38.1 100.5    13.7      M    M
 32000  -44.7 -48.5   195   62   32   9.8   5.4   37.7  99.8    13.8      M    M
 30000  -38.7 -37.7   205   65   33   8.9   4.9   37.0  98.7    13.7      M    M
 29000  -36.0 -32.8   210   64   33   8.9   4.9   36.6  98.0    13.6      M    M
 28000  -33.3 -27.9   210   63   32   8.8   4.8   36.3  97.3    13.5      M    M
 27000  -30.7 -23.3   215   62   32   6.5   3.6   36.0  96.7    13.4      M    M
 26000  -29.4 -20.9   215   61   32   8.3   4.6   33.9  93.0    11.9      M    M
 25000  -28.4 -19.1   220   61   31   3.0   1.7   31.5  88.8    10.1      M    M
 24000  -26.0 -14.8   220   63   32   6.4   3.5   30.8  87.4     9.7      M    M
 23000  -23.8 -10.8   220   62   32   9.0   5.0   30.0  85.9     9.1      M    M
 22000  -21.0  -5.8   225   62   32   9.4   5.1   29.8  85.6     9.1      M    M
 21000  -18.4  -1.1   225   61   32   8.2   4.5   29.3  84.8     8.8      M    M
 20000  -16.0   3.2   230   61   31   9.6   5.3   28.8  83.9     8.4      M    M
 19500  -15.4   4.3   235   59   30  -0.1  -0.1   27.8  82.0     7.5      M    M
 19000  -14.6   5.7   235   56   29   7.9   4.3   27.1  80.7     7.0      M    M
 18500  -13.5   7.7   240   54   28   8.2   4.5   26.7  80.1     6.7      M    M
 18000  -12.3   9.9   240   56   29   6.4   3.5   26.3  79.4     6.4      M    M
 17500  -11.3  11.7   240   58   30   6.7   3.7   25.8  78.4     6.0      M    M
 17000  -10.3  13.5   240   60   31   6.7   3.7   25.3  77.5     5.6      M    M
 16500   -9.3  15.3   240   59   30   6.6   3.6   24.8  76.6     5.2      M    M
 16000   -8.2  17.2   245   57   30   5.1   2.8   24.3  75.7     4.8      M    M
 15500   -7.9  17.8   245   52   27   2.1   1.1   23.1  73.5     3.7      M    M
 15000   -6.8  19.8   250   43   22   9.4   5.1   22.1  71.7     2.6      M    M
 14500   -5.4  22.3   250   38   19   9.0   4.9   22.0  71.5     2.5      M    M
 14000   -4.1  24.6   255   32   17   9.0   4.9   21.9  71.4     2.5      M    M
 13500   -2.8  27.0   255   28   15   9.0   4.9   21.8  71.2     2.3      M    M
 13000   -1.4  29.5   255   25   13   9.0   4.9   21.7  71.0     2.2      M    M
 12500   -0.1  31.8   260   24   12   9.0   5.0   21.5  70.8     2.1      M    M
 12000    1.2  34.2   260   23   12   9.0   5.0   21.4  70.6     2.0      M    M
 11500    2.5  36.5   255   24   12   9.1   5.0   21.3  70.3     1.8      M    M
 11000    3.9  39.0   245   24   13   9.1   5.0   21.1  70.0     1.7      M    M
 10500    5.2  41.4   240   25   13   9.1   5.0   21.0  69.8     1.5      M    M
 10250    5.9  42.6   240   26   13   9.1   5.0   20.9  69.7     1.5      M    M
 10000    6.5  43.7   235   27   14   9.1   5.0   20.9  69.6     1.4      M    M
  9750    7.2  45.0   235   27   14   8.9   4.9   20.9  69.5     1.4      M    M
  9500    7.9  46.2   230   26   14   8.8   4.8   20.8  69.4     1.3      M    M
  9250    8.5  47.3   230   26   13   8.8   4.9   20.7  69.3     1.2      M    M
  9000    9.2  48.6   225   26   13   8.8   4.9   20.7  69.2     1.2      M    M
  8750    9.8  49.6   220   25   13   8.8   4.9   20.6  69.1     1.1      M    M
  8500   10.5  50.9   220   25   13   8.8   4.9   20.6  69.0     1.1      M    M
  8250   11.1  52.0   220   24   13   8.8   4.9   20.5  68.9     1.0      M    M
  8000   11.8  53.2   215   24   12   8.8   4.9   20.4  68.8     0.9      M    M
  7750   12.4  54.3   215   23   12   8.8   4.9   20.4  68.7     0.9      M    M
  7500   13.1  55.6   210   23   12   8.9   4.9   20.3  68.5     0.8      M    M
  7250   13.7  56.7   210   22   12   8.9   4.9   20.2  68.4     0.7      M    M
  7000   14.4  57.9   205   22   11   8.9   4.9   20.2  68.3     0.6      M    M
  6750   15.1  59.2   205   22   11   8.8   4.8   20.1  68.2     0.6      M    M
  6500   15.7  60.3   200   22   12   8.9   4.9   20.0  68.0     0.5      M    M
  6250   16.4  61.5   200   23   12   8.6   4.7   19.9  67.9     0.4      M    M
  6000   17.0  62.6   195   23   12   9.7   5.3   19.9  67.8     0.3      M    M
  5750   17.7  63.9   195   18    9   5.8   3.2   19.8  67.6     0.2      M    M
  5500   17.5  63.5   200   13    7 -12.2  -6.7   18.9  66.1    -0.6      M    M

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

           04/23/2014 at 0900 MDT          |       04/23/2014 at 1200 MDT
                                           |
K index... +2.2  LI... +2.4                | K index... +7.0  LI... +2.4
CAPE... 0.0  CIN... -0.6                   | CAPE... 0.0  CIN... -0.1
                                           |
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 -60.2 -76.4  245  35 18  -1.2  -0.7 | -58.9 -74.0  240  30 16  -0.9  -0.5
 45000 -61.9 -79.4  235  70 36  -1.5  -0.8 | -60.2 -76.4  235  64 33  -1.1  -0.6
 40000 -58.7 -73.7  225  74 38   2.2   1.2 | -58.3 -72.9  225  77 39   1.3   0.7
 38000 -56.6 -69.9  220  76 39   4.6   2.5 | -56.9 -70.4  225  76 39   3.2   1.8
 36000 -53.9 -65.0  215  78 40   4.6   2.5 | -55.0 -67.0  225  70 36   3.2   1.8
 34000 -50.9 -59.6  210  80 41   7.1   3.9 | -52.7 -62.9  220  64 33   7.8   4.3
 32000 -46.8 -52.2  215  75 39   6.9   3.8 | -48.4 -55.1  225  62 32   7.3   4.0
 30000 -42.6 -44.7  215  70 36   7.2   3.9 | -43.9 -47.0  230  59 30   8.3   4.5
 29000 -40.2 -40.4  215  67 34   7.2   3.9 | -40.8 -41.4  230  55 28   8.2   4.5
 28000 -37.8 -36.0  220  64 33   7.2   3.9 | -38.4 -37.1  235  52 27   8.2   4.5
 27000 -35.6 -32.1  220  61 32   7.6   4.2 | -35.9 -32.6  235  50 25   7.9   4.3
 26000 -33.3 -27.9  220  59 31   8.0   4.4 | -33.6 -28.5  235  46 24   7.7   4.2
 25000 -30.9 -23.6  220  57 30   8.0   4.4 | -31.3 -24.3  235  43 22   7.7   4.2
 24000 -28.5 -19.3  220  55 29   7.9   4.4 | -29.0 -20.2  235  39 20   7.8   4.3
 23000 -26.1 -15.0  225  54 28   7.8   4.3 | -26.5 -15.7  235  38 19   8.4   4.6
 22000 -23.8 -10.8  225  53 27   7.8   4.3 | -24.0 -11.2  235  36 19   8.4   4.6
 21000 -21.4  -6.5  225  51 26   7.9   4.3 | -21.5  -6.7  235  35 18   8.3   4.5
 20000 -19.1  -2.4  225  49 25   8.0   4.4 | -19.0  -2.2  235  35 18   8.2   4.5
 19500 -17.9  -0.2  230  48 25   8.0   4.4 | -17.8  -0.0  235  35 18   8.2   4.5
 19000 -16.7   1.9  230  47 24   8.0   4.4 | -16.6   2.1  235  35 18   8.2   4.5
 18500 -15.5   4.1  230  46 24   7.9   4.3 | -15.4   4.3  235  35 18   8.1   4.4
 18000 -14.3   6.3  230  45 23   7.6   4.2 | -14.2   6.4  235  35 18   7.9   4.3
 17500 -13.2   8.2  230  44 23   7.6   4.2 | -13.0   8.6  235  36 18   8.0   4.4
 17000 -12.0  10.4  230  43 22   7.9   4.3 | -11.9  10.6  235  36 18   6.4   3.5
 16500 -10.9  12.4  235  42 22   7.9   4.3 | -11.0  12.2  235  35 18   6.2   3.4
 16000  -9.7  14.5  235  41 21   7.9   4.3 | -10.1  13.8  235  35 18   5.5   3.0
 15500  -8.5  16.7  235  42 22   7.9   4.3 |  -9.4  15.1  240  33 17   4.7   2.6
 15000  -6.8  19.8  240  43 22   6.9   3.8 |  -8.7  16.3  240  32 16   4.7   2.6
 14500  -5.8  21.6  245  42 21   6.6   3.6 |  -7.9  17.8  240  28 14   4.2   2.3
 14000  -4.9  23.2  245  40 21   6.4   3.5 |  -7.3  18.9  240  25 13   5.4   3.0
 13500  -4.0  24.8  245  37 19   6.2   3.4 |  -6.4  20.5  240  21 11   6.8   3.7
 13000  -3.1  26.4  250  33 17   6.6   3.6 |  -5.4  22.3  240  17  9   7.6   4.1
 12500  -2.0  28.4  245  30 15   7.8   4.3 |  -4.1  24.6  240  15  8   9.3   5.1
 12000  -0.9  30.4  245  26 13   7.8   4.3 |  -2.8  27.0  240  14  7   9.2   5.1
 11500   0.2  32.4  245  24 13   7.8   4.3 |  -1.4  29.5  240  12  6   9.2   5.0
 11000   1.4  34.5  250  23 12   7.5   4.1 |  -0.1  31.8  245  10  5   9.2   5.0
 10500   2.3  36.1  255  21 11   5.4   3.0 |   1.3  34.3  245   9  5   9.1   5.0
 10250   2.7  36.9  255  20 11   6.8   3.7 |   2.0  35.6  250   8  4   9.8   5.4
 10000   3.3  37.9  255  19 10   8.4   4.6 |   2.7  36.9  250   8  4  10.6   5.8
  9750   3.9  39.0  255  17  9   8.2   4.5 |   3.5  38.3  250   8  4  10.3   5.7
  9500   4.5  40.1  255  16  8   8.2   4.5 |   4.3  39.7  255   8  4  10.4   5.7
  9250   5.1  41.2  250  14  7   8.0   4.4 |   5.1  41.2  255   7  4   9.9   5.4
  9000   5.6  42.1  250  13  7   7.7   4.2 |   5.8  42.4  255   7  4   9.0   4.9
  8750   6.2  43.2  250  11  6   8.3   4.5 |   6.4  43.5  255   7  4   9.5   5.2
  8500   6.8  44.2  245  10  5   8.9   4.9 |   7.2  45.0  260   7  4  10.0   5.5
  8250   7.5  45.5  240   9  5   8.2   4.5 |   7.9  46.2  260   7  4   9.9   5.4
  8000   8.1  46.6  235   8  4  10.5   5.7 |   8.7  47.7  260   7  4  11.2   6.1
  7750   9.0  48.2  230   7  3  10.4   5.7 |   9.5  49.1  260   7  4  10.4   5.7
  7500   9.6  49.3  225   6  3   8.2   4.5 |  10.2  50.4  260   7  4   9.1   5.0
  7250  10.3  50.5  220   6  3   8.8   4.8 |  10.9  51.6  265   7  4   9.4   5.1
  7000  10.9  51.6  215   5  3   8.5   4.7 |  11.6  52.9  265   7  4   9.3   5.1
  6750  11.5  52.7  215   5  2   7.8   4.3 |  12.3  54.1  265   7  4  10.0   5.5
  6500  12.1  53.8  215   5  2   8.5   4.7 |  13.1  55.6  265   7  4  10.3   5.6
  6250  12.6  54.7  215   5  3   4.9   2.7 |  13.9  57.0  270   7  4  10.6   5.8
  6000  12.7  54.9  215   5  3   0.2   0.1 |  14.7  58.5  270   7  4  11.5   6.3
  5750  12.8  55.0  215   5  3   3.6   2.0 |  15.5  59.9  270   7  3  11.0   6.0
  5500  13.2  55.8  215   5  2  10.5   5.8 |  16.5  61.7  275   6  3  16.7   9.1

           04/23/2014 at 1500 MDT          |       04/23/2014 at 1800 MDT
                                           |
K index... +20.3  LI... +1.1               | K index... +22.5  LI... +0.9
CAPE... +1.1  CIN... -6.7                  | CAPE... 0.0  CIN... -8.8
                                           |
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 -58.2 -72.8  230  30 16  -0.6  -0.3 | -57.5 -71.5  245  32 17   0.9   0.5
 45000 -59.2 -74.6  235  62 32  -0.3  -0.2 | -56.0 -68.8  250  54 28   0.8   0.4
 40000 -58.2 -72.8  230  71 36   0.7   0.4 | -55.7 -68.3  235  62 32   0.2   0.1
 38000 -57.4 -71.3  230  72 37   2.5   1.4 | -55.7 -68.3  230  64 33  -0.1  -0.1
 36000 -55.9 -68.6  225  71 37   2.5   1.4 | -55.8 -68.4  220  65 33  -0.1  -0.1
 34000 -54.1 -65.4  225  70 36   7.4   4.1 | -55.7 -68.3  210  67 34   5.2   2.9
 32000 -49.4 -56.9  225  67 34   7.8   4.3 | -50.9 -59.6  210  61 31   8.0   4.4
 30000 -44.2 -47.6  230  62 32   7.4   4.1 | -45.4 -49.7  205  54 28   8.3   4.5
 29000 -41.9 -43.4  225  57 29   7.5   4.1 | -42.9 -45.2  200  53 27   8.3   4.6
 28000 -39.7 -39.5  225  53 27   7.5   4.1 | -40.5 -40.9  200  51 26   8.3   4.6
 27000 -37.5 -35.5  220  49 25   8.0   4.4 | -38.0 -36.4  195  49 25   8.4   4.6
 26000 -34.9 -30.8  220  47 24   8.7   4.8 | -35.4 -31.7  195  46 24   8.6   4.7
 25000 -32.2 -26.0  215  45 23   8.7   4.8 | -32.9 -27.2  195  43 22   8.6   4.7
 24000 -29.6 -21.3  215  43 22   8.7   4.8 | -30.3 -22.5  190  41 21   8.7   4.8
 23000 -27.2 -17.0  215  43 22   8.1   4.4 | -27.9 -18.2  195  39 20   7.7   4.2
 22000 -24.7 -12.5  220  44 22   8.1   4.4 | -25.6 -14.1  195  37 19   7.7   4.2
 21000 -22.3  -8.1  220  44 23   7.8   4.3 | -23.4 -10.1  200  36 18   7.5   4.1
 20000 -20.1  -4.2  220  43 22   7.5   4.1 | -21.3  -6.3  205  33 17   6.9   3.8
 19500 -19.0  -2.2  225  43 22   7.5   4.1 | -20.3  -4.5  210  32 17   6.9   3.8
 19000 -17.8  -0.0  225  42 22   7.4   4.1 | -19.3  -2.7  210  31 16   6.9   3.8
 18500 -16.7   1.9  225  42 21   7.0   3.9 | -18.2  -0.8  215  30 15   6.8   3.7
 18000 -15.9   3.4  225  40 21   5.2   2.9 | -17.3   0.9  220  29 15   5.6   3.1
 17500 -15.1   4.8  225  39 20   5.4   3.0 | -16.5   2.3  225  27 14   5.7   3.1
 17000 -14.3   6.3  225  37 19   5.3   2.9 | -15.7   3.7  230  26 13   6.2   3.4
 16500 -13.6   7.5  225  33 17   5.4   3.0 | -14.7   5.5  235  23 12   6.3   3.5
 16000 -12.8   9.0  225  30 15   6.3   3.4 | -13.8   7.2  240  21 11   6.7   3.7
 15500 -11.8  10.8  220  26 14   7.3   4.0 | -12.8   9.0  240  19 10   7.3   4.0
 15000 -10.2  13.6  215  21 11   8.2   4.5 | -11.1  12.0  245  16  8   7.6   4.2
 14500  -8.9  16.0  210  18  9   8.5   4.7 | -10.0  14.0  245  15  8   7.9   4.3
 14000  -7.7  18.1  210  15  8   8.5   4.6 |  -8.8  16.2  250  14  7   8.3   4.6
 13500  -6.5  20.3  210  13  7   8.4   4.6 |  -7.5  18.5  255  14  7   9.0   4.9
 13000  -5.2  22.6  215  10  5   8.6   4.7 |  -6.2  20.8  260  13  7   9.0   5.0
 12500  -3.9  25.0  225   8  4   9.1   5.0 |  -4.8  23.4  270  13  7   9.1   5.0
 12000  -2.6  27.3  235   6  3   9.2   5.0 |  -3.5  25.7  275  13  7   9.1   5.0
 11500  -1.2  29.8  250   6  3   9.7   5.3 |  -2.1  28.2  285  14  7   9.1   5.0
 11000   0.3  32.5  270   5  3   9.6   5.2 |  -0.7  30.7  290  15  8   8.9   4.9
 10500   1.7  35.1  285   6  3   9.0   4.9 |   0.5  32.9  300  16  8   7.7   4.2
 10250   2.4  36.3  285   6  3  10.2   5.6 |   1.1  34.0  300  17  9   8.5   4.6
 10000   3.2  37.8  290   6  3  11.1   6.1 |   1.8  35.2  305  17  9   9.4   5.1
  9750   4.0  39.2  295   7  3  10.2   5.6 |   2.4  36.3  310  18  9   9.2   5.1
  9500   4.7  40.5  300   7  4  10.2   5.6 |   3.1  37.6  315  18  9   9.2   5.0
  9250   5.5  41.9  300   7  4   9.6   5.3 |   3.8  38.8  320  18  9   9.1   5.0
  9000   6.2  43.2  300   7  4   9.1   5.0 |   4.5  40.1  325  19 10   8.7   4.8
  8750   6.9  44.4  305   7  4   9.8   5.4 |   5.1  41.2  325  19 10   9.1   5.0
  8500   7.6  45.7  305   8  4  10.1   5.5 |   5.8  42.4  325  19 10   9.4   5.2
  8250   8.4  47.1  305   8  4  10.3   5.7 |   6.5  43.7  330  19 10   9.4   5.1
  8000   9.2  48.6  310   8  4  11.1   6.1 |   7.3  45.1  330  19 10  10.7   5.9
  7750  10.0  50.0  310   8  4  10.0   5.5 |   8.1  46.6  330  19 10  10.1   5.5
  7500  10.7  51.3  310   8  4   9.0   4.9 |   8.7  47.7  335  19 10   8.7   4.8
  7250  11.4  52.5  310   9  4   9.6   5.2 |   9.4  48.9  335  19 10   9.2   5.1
  7000  12.1  53.8  310   9  5  10.1   5.6 |  10.1  50.2  335  19 10   9.7   5.3
  6750  12.9  55.2  315   9  5  10.0   5.5 |  10.9  51.6  335  19 10  10.0   5.5
  6500  13.6  56.5  315   9  5   9.5   5.2 |  11.6  52.9  335  19 10   9.8   5.4
  6250  14.3  57.7  315   9  5  10.5   5.7 |  12.3  54.1  335  19 10  10.3   5.6
  6000  15.2  59.4  315   9  5  11.8   6.5 |  13.1  55.6  335  18  9  10.9   6.0
  5750  16.0  60.8  315   9  5  10.7   5.9 |  13.9  57.0  335  17  9  10.6   5.8
  5500  16.9  62.4  315   9  5  15.2   8.4 |  14.7  58.5  335  16  8  12.2   6.7
________________________________________________________________________________

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




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NOAA National Weather Service
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Silver Spring, MD 20910
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Page last modified: May 16, 2007
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