Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

000
UXUS97 KBOU 201243
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0642 MDT Saturday, September 20, 2014

This forecast is for Saturday, September 20, 2014:

If the trigger temperature of 79.9 F/26.6 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 122 ft/min (0.6 m/s)
   Maximum height of thermals.................. 7566 ft MSL (2281 ft AGL)

Forecast maximum temperature................... 77.0 F/25.5 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 5944 ft MSL (659 ft AGL)
Thermal soaring outlook for Sunday 09/21....... Poor

Wave Soaring Index............................. Fair
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 15373 ft MSL (10088 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 19802 ft MSL (14517 ft AGL)
Wave soaring outlook for Sunday 09/21.......... Fair

Remarks... Isolated afternoon thunderstorms

Sunrise/Sunset.................... 06:45:14 / 19:01:21 MDT
Total possible sunshine........... 12 hr 16 min 7 sec (736 min 7 sec)
Altitude of sun at 12:52:47 MDT... 51.14 degrees

Upper air data from rawinsonde observation taken on 09/20/2014 at 0600 MDT

Freezing level.................. 15911 ft MSL (10626 ft AGL)
Convective condensation level... 16251 ft MSL (10966 ft AGL)
Lifted condensation level....... 13521 ft MSL (8235 ft AGL)
Lifted index.................... +1.3
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  -67.1 -88.8   280   52   27   4.7   2.6   81.5 178.6    32.8      M    M
 45000  -61.3 -78.3   280   77   40   7.2   3.9   65.5 149.9    25.3      M    M
 40000  -51.8 -61.2   285   81   42   7.5   4.1   57.6 135.6    21.8      M    M
 38000  -47.3 -53.1   285   78   40   7.5   4.1   55.5 132.0    21.0      M    M
 36000  -42.8 -45.0   285   69   35   7.4   4.1   53.7 128.6    20.2      M    M
 34000  -40.1 -40.2   285   45   23   1.9   1.0   49.3 120.8    17.6      M    M
 32000  -36.9 -34.4   295   29   15   6.9   3.8   45.7 114.2    15.3      M    M
 30000  -32.0 -25.6   290   25   13   8.7   4.8   43.4 110.2    14.0      M    M
 29000  -29.8 -21.6   295   21   11   0.7   0.4   42.6 108.6    13.5      M    M
 28000  -28.3 -18.9   305   19   10   8.0   4.4   40.7 105.3    12.3      M    M
 27000  -25.5 -13.9   315   16    8   9.2   5.0   40.6 105.0    12.3      M    M
 26000  -23.0  -9.4   330   15    8   8.1   4.5   40.0 103.9    12.0      M    M
 25000  -20.5  -4.9   345   14    7   8.2   4.5   39.4 102.9    11.7      M    M
 24000  -18.0  -0.4   340   15    8   8.6   4.7   38.9 102.0    11.4      M    M
 23000  -15.4   4.3   340   16    8   8.6   4.7   38.5 101.3    11.1      M    M
 22000  -13.0   8.6   335   17    9   8.5   4.6   37.9 100.3    10.8      M    M
 21000  -10.4  13.3   330   19   10   8.6   4.7   37.5  99.5    10.6      M    M
 20000   -8.1  17.4   330   20   10   5.8   3.2   36.9  98.3    10.1      M    M
 19500   -7.2  19.0   325   21   11   5.9   3.2   36.2  97.1     9.6      M    M
 19000   -6.2  20.8   325   20   11   6.7   3.7   35.6  96.0     9.1      M    M
 18500   -5.3  22.5   320   19   10   6.7   3.7   35.0  95.0     8.7      M    M
 18000   -4.3  24.3   320   18    9   6.8   3.7   34.5  94.1     8.3      M    M
 17500   -3.4  25.9   315   17    9   5.0   2.7   33.9  93.0     7.7      M    M
 17000   -2.7  27.1   310   16    8   4.9   2.7   33.1  91.5     7.0      M    M
 16500   -1.7  28.9   305   15    8   8.8   4.8   32.6  90.6     6.6      M    M
 16000   -0.5  31.1   300   14    7   8.6   4.7   32.4  90.3     6.4      M    M
 15500    0.6  33.1   300   12    6   4.3   2.4   32.1  89.7     6.0      M    M
 15000    1.0  33.8   305    8    4   4.3   2.4   30.2  86.4     4.2      M    M
 14500    1.4  34.5   310    6    3   6.3   3.5   29.4  84.9     3.1      M    M
 14000    2.5  36.5   315    4    2   8.7   4.8   29.1  84.4     2.9      M    M
 13500    3.8  38.8   320    3    2   8.7   4.8   28.9  84.1     2.7      M    M
 13000    5.1  41.2   330    3    1   8.7   4.8   28.8  83.8     2.5      M    M
 12500    6.4  43.5   345    2    1   8.7   4.8   28.6  83.6     2.4      M    M
 12000    7.6  45.7   360    2    1   8.8   4.8   28.5  83.3     2.3      M    M
 11500    8.9  48.0   010    2    1   8.8   4.8   28.3  83.0     2.1      M    M
 11000   10.2  50.4   015    2    1   8.8   4.8   28.1  82.7     1.9      M    M
 10500   11.5  52.7   025    2    1   8.9   4.9   28.0  82.4     1.7      M    M
 10250   12.2  54.0   005    2    1   9.1   5.0   27.9  82.3     1.7      M    M
 10000   12.8  55.0   340    2    1   9.1   5.0   27.9  82.2     1.6      M    M
  9750   13.5  56.3   320    2    1   9.1   5.0   27.8  82.1     1.6      M    M
  9500   14.2  57.6   305    3    1   9.1   5.0   27.8  82.0     1.6      M    M
  9250   14.9  58.8   295    3    2   9.1   5.0   27.8  82.0     1.5      M    M
  9000   15.6  60.1   290    4    2   9.1   5.0   27.7  81.9     1.5      M    M
  8750   16.3  61.3   290    3    2   9.0   4.9   27.7  81.8     1.5      M    M
  8500   17.0  62.6   290    2    1   9.5   5.2   27.6  81.7     1.4      M    M
  8250   17.6  63.7   290    1    0   5.9   3.2   27.5  81.5     1.4      M    M
  8000   17.8  64.0   000    0    0   2.8   1.5   27.0  80.7     0.9      M    M
  7750   18.1  64.6   230    1    0   3.3   1.8   26.5  79.8     0.4      M    M
  7500   18.3  64.9   230    2    1   4.3   2.3   26.1  78.9    -0.1    118  0.6
  7250   18.7  65.7   230    2    1   7.3   4.0   25.8  78.4    -0.4     98  0.5
  7000   19.3  66.7   230    3    2   8.0   4.4   25.6  78.2    -0.6     74  0.4
  6750   19.9  67.8   235    4    2   8.9   4.9   25.5  77.9    -0.7     49  0.2
  6500   20.5  68.9   240    5    3   4.5   2.5   25.4  77.7    -0.9     24  0.1
  6250   20.5  68.9   245    6    3   0.9   0.5   24.7  76.5    -1.5     14  0.1
  6000   20.4  68.7   245    7    4  -7.3  -4.0   23.9  75.1    -2.4     10  0.0
  5750   19.2  66.6   245    5    2 -23.0 -12.6   22.0  71.6    -4.4     40  0.2
  5500   17.2  63.0   245    2    1 -25.3 -13.9   19.3  66.8    -7.1     92  0.5

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

           09/20/2014 at 0900 MDT          |       09/20/2014 at 1200 MDT
                                           |
K index... +22.2  LI... +0.9               | K index... +25.8  LI... +1.2
CAPE... +31.1  CIN... -235.8               | CAPE... +35.6  CIN... -241.0
                                           |
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 -67.2 -89.0  285  50 26   2.7   1.5 | -66.9 -88.4  290  47 24   2.2   1.2
 45000 -61.6 -78.9  280  70 36   6.4   3.5 | -61.9 -79.4  285  67 35   6.3   3.5
 40000 -51.4 -60.5  285  75 39   6.9   3.8 | -51.8 -61.2  285  73 38   7.0   3.8
 38000 -47.3 -53.1  290  67 35   6.9   3.8 | -47.6 -53.7  285  66 34   7.0   3.8
 36000 -43.1 -45.6  290  60 31   7.1   3.9 | -43.4 -46.1  290  59 30   7.3   4.0
 34000 -39.9 -39.8  290  41 21   5.1   2.8 | -40.2 -40.4  285  41 21   5.1   2.8
 32000 -36.9 -34.4  300  21 11   5.0   2.8 | -37.1 -34.8  285  21 11   5.1   2.8
 30000 -32.7 -26.9  310  13  6   7.6   4.2 | -32.9 -27.2  285  10  5   7.4   4.0
 29000 -29.9 -21.8  325   9  5   7.6   4.2 | -30.2 -22.4  295   4  2   7.4   4.0
 28000 -27.6 -17.7  340   8  4   7.8   4.3 | -27.9 -18.2  360   1  1   8.3   4.5
 27000 -25.2 -13.4  350   8  4   7.8   4.3 | -25.5 -13.9  035   1  1   8.2   4.5
 26000 -22.9  -9.2  355   7  4   7.8   4.3 | -23.0  -9.4  055   2  1   8.2   4.5
 25000 -20.5  -4.9  360   7  4   7.9   4.4 | -20.5  -4.9  065   3  1   8.2   4.5
 24000 -18.1  -0.6  360   8  4   8.1   4.5 | -18.1  -0.6  055   1  1   8.2   4.5
 23000 -15.7   3.7  360   8  4   8.2   4.5 | -15.6   3.9  280   1  0   8.3   4.5
 22000 -13.3   8.1  360   8  4   7.8   4.3 | -13.2   8.2  260   2  1   7.7   4.2
 21000 -11.1  12.0  345   8  4   7.4   4.0 | -11.0  12.2  280   5  2   7.3   4.0
 20000  -8.8  16.2  330  10  5   7.4   4.0 |  -8.8  16.2  290   7  4   7.3   4.0
 19500  -7.7  18.1  325  10  5   7.4   4.1 |  -7.7  18.1  290   8  4   7.2   4.0
 19000  -6.8  19.8  320  11  6   6.0   3.3 |  -6.8  19.8  290  10  5   5.8   3.2
 18500  -5.8  21.6  315  12  6   6.1   3.4 |  -5.9  21.4  290  11  6   5.9   3.2
 18000  -4.9  23.2  310  13  6   6.2   3.4 |  -5.0  23.0  290  12  6   6.3   3.5
 17500  -4.0  24.8  305  13  7   6.3   3.4 |  -4.1  24.6  290  13  7   6.7   3.7
 17000  -3.1  26.4  300  14  7   6.4   3.5 |  -3.2  26.2  285  13  7   6.8   3.7
 16500  -2.2  28.0  295  14  7   7.0   3.8 |  -2.2  28.0  285  14  7   7.4   4.0
 16000  -1.2  29.8  290  15  7   7.1   3.9 |  -1.2  29.8  280  14  7   7.6   4.2
 15500  -0.3  31.5  285  15  8   7.6   4.2 |  -0.2  31.6  275  14  7   7.9   4.4
 15000   0.8  33.4  280  14  7   7.8   4.3 |   1.4  34.5  270  13  7   8.2   4.5
 14500   2.3  36.1  280  13  7   6.8   3.7 |   2.5  36.5  265  12  6   7.0   3.9
 14000   3.2  37.8  275  12  6   7.0   3.8 |   3.5  38.3  260  11  6   7.1   3.9
 13500   4.1  39.4  270  10  5   6.6   3.6 |   4.6  40.3  255  11  5   7.3   4.0
 13000   5.1  41.2  260  10  5   6.5   3.6 |   5.7  42.3  245  11  6   7.4   4.0
 12500   6.0  42.8  250   9  5   6.6   3.6 |   6.8  44.2  240  12  6   7.3   4.0
 12000   7.0  44.6  245   8  4   6.6   3.6 |   7.9  46.2  230  12  6   7.2   4.0
 11500   8.0  46.4  240   7  4   6.9   3.8 |   8.9  48.0  225  13  6   6.9   3.8
 11000   9.0  48.2  250   5  3   7.0   3.8 |   9.9  49.8  225  11  6   6.7   3.7
 10500  10.1  50.2  265   3  2   5.0   2.8 |  10.9  51.6  220  10  5   5.4   3.0
 10250  10.3  50.5  275   3  2   2.6   1.4 |  11.2  52.2  220   9  5   5.0   2.7
 10000  10.5  50.9  295   4  2   3.3   1.8 |  11.6  52.9  225   8  4   6.4   3.5
  9750  10.6  51.1  310   6  3   3.8   2.1 |  12.1  53.8  235   6  3   6.3   3.4
  9500  10.8  51.4  320   8  4  -1.0  -0.6 |  12.3  54.1  255   5  2  -1.8  -1.0
  9250  10.4  50.7  325   8  4  -5.8  -3.2 |  11.7  53.1  265   4  2  -7.2  -4.0
  9000  10.0  50.0  330   8  4  -2.9  -1.6 |  11.2  52.2  285   3  2  -6.3  -3.5
  8750   9.8  49.6  340   8  4  -0.4  -0.2 |  10.6  51.1  320   3  1  -5.1  -2.8
  8500   9.8  49.6  355   7  3   3.0   1.7 |  10.4  50.7  350   3  1   0.9   0.5
  8250  10.2  50.4  030   6  3   5.3   2.9 |  10.6  51.1  005   2  1   2.7   1.5
  8000  10.5  50.9  055   8  4   4.4   2.4 |  10.8  51.4  020   2  1   4.1   2.2
  7750  10.8  51.4  070  11  6   3.8   2.1 |  11.3  52.3  035   2  1   7.7   4.2
  7500  11.1  52.0  070  12  6   3.4   1.9 |  11.9  53.4  030   2  1   8.1   4.5
  7250  11.3  52.3  065  11  6   3.6   2.0 |  12.4  54.3  020   3  1   7.7   4.2
  7000  11.6  52.9  060  10  5   3.2   1.7 |  13.0  55.4  005   3  1   8.4   4.6
  6750  11.8  53.2  050   9  5   3.6   2.0 |  13.7  56.7  360   3  2   9.8   5.4
  6500  12.2  54.0  035   8  4   4.6   2.5 |  14.4  57.9  355   3  2  10.3   5.6
  6250  12.5  54.5  010   8  4   3.7   2.0 |  15.2  59.4  355   3  2   9.9   5.4
  6000  12.8  55.0  350   9  4   6.3   3.4 |  15.9  60.6  350   3  2  11.0   6.1
  5750  13.6  56.5  345   9  5  12.7   7.0 |  16.9  62.4  350   3  2  16.8   9.2
  5500  14.6  58.3  340   8  4  15.9   8.7 |  18.4  65.1  350   3  2  22.7  12.5

           09/20/2014 at 1500 MDT          |       09/20/2014 at 1800 MDT
                                           |
K index... +22.6  LI... -0.1               | K index... +28.2  LI... -2.2
CAPE... +220.4  CIN... -185.9              | CAPE... +472.1  CIN... -100.8
                                           |
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 -67.2 -89.0  280  47 24   2.4   1.3 | -67.0 -88.6  285  47 24   2.8   1.5
 45000 -61.3 -78.3  285  66 34   6.5   3.6 | -60.9 -77.6  285  65 33   6.4   3.5
 40000 -51.5 -60.7  285  71 36   6.8   3.7 | -51.3 -60.3  285  72 37   6.5   3.6
 38000 -47.5 -53.5  285  65 34   6.8   3.7 | -47.4 -53.3  285  69 35   6.5   3.6
 36000 -43.4 -46.1  285  60 31   6.9   3.8 | -43.5 -46.3  285  66 34   6.5   3.6
 34000 -39.7 -39.5  285  47 24   6.1   3.3 | -39.6 -39.3  280  55 28   6.5   3.6
 32000 -36.0 -32.8  285  33 17   6.1   3.3 | -35.2 -31.4  280  41 21   7.0   3.9
 30000 -31.7 -25.1  275  18  9   6.5   3.6 | -31.0 -23.8  280  28 15   7.0   3.8
 29000 -29.7 -21.5  265  12  6   6.5   3.6 | -28.9 -20.0  280  22 11   7.0   3.8
 28000 -27.7 -17.9  240   7  4   8.0   4.4 | -26.8 -16.2  275  16  8   7.2   4.0
 27000 -25.3 -13.5  225   7  3   8.0   4.4 | -24.6 -12.3  270  13  7   7.3   4.0
 26000 -22.9  -9.2  210   7  3   8.0   4.4 | -22.4  -8.3  255  11  6   7.3   4.0
 25000 -20.5  -4.9  195   7  4   8.2   4.5 | -20.2  -4.4  235  10  5   7.4   4.1
 24000 -18.0  -0.4  205   7  4   8.5   4.6 | -17.9  -0.2  235  10  5   7.8   4.3
 23000 -15.4   4.3  220   7  4   8.5   4.7 | -15.5   4.1  240  10  5   7.8   4.3
 22000 -12.9   8.8  230   7  4   7.9   4.4 | -13.2   8.2  240  11  5   7.4   4.0
 21000 -10.7  12.7  250   8  4   7.5   4.1 | -11.2  11.8  260  10  5   6.9   3.8
 20000  -8.4  16.9  265   9  5   7.5   4.1 |  -9.2  15.4  280  10  5   7.1   3.9
 19500  -7.3  18.9  270  10  5   7.5   4.1 |  -8.1  17.4  290  11  6   7.2   3.9
 19000  -6.3  20.7  280  11  6   6.2   3.4 |  -7.1  19.2  295  12  6   7.2   4.0
 18500  -5.3  22.5  285  12  6   6.3   3.5 |  -6.1  21.0  305  14  7   7.3   4.0
 18000  -4.4  24.1  295  13  7   6.7   3.7 |  -5.0  23.0  310  16  8   7.2   4.0
 17500  -3.4  25.9  295  15  7   7.1   3.9 |  -4.0  24.8  310  17  9   7.2   4.0
 17000  -2.4  27.7  295  16  8   7.2   4.0 |  -2.9  26.8  310  18  9   7.3   4.0
 16500  -1.4  29.5  295  16  8   7.6   4.2 |  -1.9  28.6  310  18  9   7.9   4.4
 16000  -0.4  31.3  290  17  9   7.9   4.3 |  -0.3  31.5  305  16  8   8.0   4.4
 15500   0.6  33.1  290  16  8   7.3   4.0 |   0.7  33.3  305  14  7   7.3   4.0
 15000   2.1  35.8  285  14  7   7.4   4.0 |   1.7  35.1  300  12  6   7.4   4.1
 14500   3.1  37.6  285  13  7   7.5   4.1 |   2.8  37.0  300  10  5   8.2   4.5
 14000   4.2  39.6  280  12  6   7.5   4.1 |   4.0  39.2  295   8  4   8.2   4.5
 13500   5.4  41.7  275  10  5   8.4   4.6 |   5.2  41.4  285   7  4   8.3   4.5
 13000   6.6  43.9  265  10  5   8.6   4.7 |   6.4  43.5  275   7  4   8.3   4.6
 12500   7.9  46.2  255  10  5   7.4   4.1 |   7.7  45.9  265   8  4   7.3   4.0
 12000   8.9  48.0  240  11  6   6.8   3.7 |   8.6  47.5  250   8  4   6.7   3.7
 11500   9.9  49.8  225  12  6   6.8   3.8 |   9.6  49.3  240   7  4   6.2   3.4
 11000  11.0  51.8  220  12  6   6.7   3.7 |  10.5  50.9  220   7  3   5.6   3.1
 10500  12.0  53.6  210  12  6   3.0   1.6 |  11.4  52.5  195   7  4   2.9   1.6
 10250  12.1  53.8  210  12  6   4.8   2.6 |  11.5  52.7  195   7  4   2.4   1.3
 10000  12.8  55.0  205  11  6  11.1   6.1 |  11.8  53.2  185   6  3   5.7   3.1
  9750  13.6  56.5  200  10  5  10.3   5.7 |  12.2  54.0  165   6  3   5.4   3.0
  9500  14.3  57.7  200   9  5   6.8   3.8 |  12.5  54.5  150   5  3   3.6   2.0
  9250  14.6  58.3  200   8  4   3.4   1.9 |  12.5  54.5  130   5  2   2.2   1.2
  9000  14.8  58.6  205   7  3   3.0   1.7 |  12.7  54.9  110   5  2   6.1   3.4
  8750  14.9  58.8  205   4  2   1.6   0.9 |  13.2  55.8  095   5  3   8.2   4.5
  8500  14.9  58.8  205   2  1  -0.0  -0.0 |  13.7  56.7  090   5  3   8.5   4.7
  8250  14.7  58.5  155   1  1  -2.0  -1.1 |  14.4  57.9  090   5  3   8.8   4.8
  8000  14.5  58.1  090   2  1   0.8   0.4 |  15.1  59.2  085   5  3   9.8   5.4
  7750  14.6  58.3  080   3  1   5.9   3.2 |  15.9  60.6  085   5  3  10.9   6.0
  7500  15.2  59.4  075   3  1   9.0   4.9 |  16.7  62.1  085   5  3  10.0   5.5
  7250  15.8  60.4  075   3  1   9.3   5.1 |  17.4  63.3  085   5  3   9.8   5.4
  7000  16.5  61.7  070   3  1  10.4   5.7 |  18.1  64.6  085   5  3   9.8   5.4
  6750  17.4  63.3  075   3  1  10.8   5.9 |  18.9  66.0  080   5  3   9.8   5.4
  6500  18.1  64.6  075   3  1   9.9   5.4 |  19.6  67.3  080   5  2   9.9   5.5
  6250  18.9  66.0  070   3  1   9.8   5.4 |  20.3  68.5  080   5  2   9.6   5.3
  6000  19.6  67.3  070   2  1  11.1   6.1 |  21.1  70.0  075   5  2  10.8   5.9
  5750  20.6  69.1  070   2  1  16.6   9.1 |  21.9  71.4  075   4  2  11.9   6.5
  5500  22.0  71.6  065   2  1  21.2  11.6 |  22.7  72.9  075   4  2  10.3   5.6
________________________________________________________________________________

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.