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 21 22 23 24
000
UXUS97 KBOU 270120
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1920 MDT Tuesday, August 26, 2014

This forecast is for Wednesday, August 27, 2014:

If the trigger temperature of 70.3 F/21.3 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 295 ft/min (1.5 m/s)
   Maximum height of thermals.................. 11869 ft MSL (6582 ft AGL)

Forecast maximum temperature................... 76.0 F/24.9 C
Time of trigger temperature.................... 1030 MDT
Time of overdevelopment........................ 1600 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................. 9301 ft MSL (4014 ft AGL)
Thermal soaring outlook for Thursday 08/28..... Fair

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 PVA
Potential height of wave....................... 22532 ft MSL (17245 ft AGL)
Wave soaring outlook for Thursday 08/28........ Poor

Remarks...

Sunrise/Sunset.................... 06:22:50 / 19:39:42 MDT
Total possible sunshine........... 13 hr 16 min 52 sec (796 min 52 sec)
Altitude of sun at 13:00:51 MDT... 60.11 degrees

Upper air data from numerical model forecast valid on 08/27/2014 at 0600 MDT

Freezing level.................. 14816 ft MSL (9529 ft AGL)
Convective condensation level... 11205 ft MSL (5918 ft AGL)
Lifted condensation level....... 11526 ft MSL (6238 ft AGL)
Lifted index.................... +0.5
K index......................... +26.9

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  -64.1 -83.4   225   50   26   0.7   0.4      M     M       M      M    M
 45000  -61.4 -78.5   225   58   30   4.4   2.4      M     M       M      M    M
 40000  -54.3 -65.7   215   49   25   7.6   4.2      M     M       M      M    M
 38000  -49.6 -57.3   205   48   25   7.7   4.2      M     M       M      M    M
 36000  -45.0 -49.0   200   49   25   7.6   4.2      M     M       M      M    M
 34000  -39.7 -39.5   200   47   24   9.0   4.9      M     M       M      M    M
 32000  -33.6 -28.5   200   44   23   9.9   5.4      M     M       M      M    M
 30000  -29.0 -20.2   205   41   21   7.5   4.1   47.4 117.3    17.4      M    M
 29000  -26.8 -16.2   210   39   20   7.5   4.1   46.6 115.8    17.0      M    M
 28000  -24.5 -12.1   215   38   19   7.9   4.4   45.9 114.6    16.6      M    M
 27000  -22.1  -7.8   215   33   17   8.2   4.5   45.1 113.2    16.2      M    M
 26000  -19.7  -3.5   215   28   15   8.2   4.5   44.5 112.1    15.8      M    M
 25000  -17.3   0.9   210   23   12   8.3   4.6   44.0 111.3    15.5      M    M
 24000  -15.4   4.3   215   21   11   6.3   3.5   42.8 109.1    14.7      M    M
 23000  -13.5   7.7   215   19   10   6.4   3.5   41.6 106.8    13.7      M    M
 22000  -11.7  10.9   220   17    9   6.4   3.5   40.4 104.8    12.9      M    M
 21000  -10.0  14.0   225   16    8   5.8   3.2   39.0 102.2    11.8      M    M
 20000   -8.3  17.1   230   15    8   5.8   3.2   37.6  99.7    10.6      M    M
 19500   -7.4  18.7   230   15    8   5.9   3.2   37.0  98.6    10.1      M    M
 19000   -6.6  20.1   230   15    8   5.6   3.1   36.3  97.4     9.6      M    M
 18500   -5.8  21.6   230   14    7   5.6   3.1   35.6  96.1     9.0      M    M
 18000   -5.0  23.0   235   14    7   5.6   3.1   34.9  94.8     8.3      M    M
 17500   -4.2  24.4   235   13    7   5.8   3.2   34.2  93.5     7.7      M    M
 17000   -3.3  26.1   235   13    6   5.8   3.2   33.5  92.3     7.1      M    M
 16500   -2.5  27.5   240   12    6   5.1   2.8   32.8  91.1     6.5      M    M
 16000   -1.5  29.3   240   11    6   4.9   2.7   31.6  88.8     5.4      M    M
 15500   -0.8  30.6   245   11    6   4.8   2.6   30.8  87.4     4.7      M    M
 15000   -0.1  31.8   245   10    5   4.8   2.6   29.9  85.9     3.9      M    M
 14500    0.6  33.1   245    9    5   4.6   2.5   29.1  84.4     3.2      M    M
 14000    1.2  34.2   250    9    4   4.6   2.5   28.2  82.8     2.4      M    M
 13500    1.9  35.4   255    8    4   5.2   2.9   27.4  81.3     1.6      M    M
 13000    2.8  37.0   260    8    4   6.6   3.6   26.8  80.3     1.1      M    M
 12500    3.8  38.8   270    7    4   6.5   3.6   26.3  79.3     0.6      M    M
 12000    4.7  40.5   280    8    4   6.3   3.5   25.8  78.4     0.1      M    M
 11500    5.6  42.1   285    8    4   6.4   3.5   25.2  77.4    -0.5    459  2.3
 11000    6.5  43.7   290    8    4   6.3   3.5   24.7  76.4    -1.0    417  2.1
 10500    7.5  45.5   290    8    4   4.9   2.7   24.2  75.5    -1.6    375  1.9
 10250    7.7  45.9   290    8    4   3.9   2.2   23.7  74.6    -2.0    359  1.8
 10000    8.1  46.6   290    7    4   6.7   3.7   23.3  74.0    -2.4    340  1.7
  9750    8.6  47.5   290    7    4   7.9   4.3   23.2  73.7    -2.6    317  1.6
  9500    9.2  48.6   290    7    4   6.8   3.8   23.0  73.4    -2.8    294  1.5
  9250    9.6  49.3   290    7    4   4.9   2.7   22.7  72.8    -3.1    274  1.4
  9000    9.9  49.8   290    7    4   6.0   3.3   22.3  72.2    -3.5    256  1.3
  8750   10.5  50.9   290    7    4   7.7   4.2   22.1  71.8    -3.7    233  1.2
  8500   11.0  51.8   290    7    4   6.6   3.6   21.9  71.5    -3.9    210  1.1
  8250   11.4  52.5   290    7    4   5.8   3.2   21.7  71.0    -4.2    189  1.0
  8000   11.8  53.2   295    8    4   6.0   3.3   21.4  70.4    -4.5    169  0.9
  7750   12.3  54.1   295    8    4   6.3   3.5   21.1  69.9    -4.8    148  0.8
  7500   12.8  55.0   300    8    4   6.2   3.4   20.8  69.5    -5.1    127  0.6
  7250   13.2  55.8   305    8    4   6.2   3.4   20.5  69.0    -5.4    106  0.5
  7000   13.6  56.5   305    8    4   5.8   3.2   20.3  68.5    -5.7     86  0.4
  6750   14.0  57.2   310    7    4   5.5   3.0   19.9  67.9    -6.0     66  0.3
  6500   14.4  57.9   310    7    3   6.4   3.5   19.6  67.4    -6.4     47  0.2
  6250   14.9  58.8   305    6    3   7.1   3.9   19.4  67.0    -6.7     27  0.1
  6000   15.3  59.5   295    5    2   6.6   3.6   19.2  66.6    -7.0      6  0.0
  5750   15.8  60.4   280    4    2   5.9   3.3   19.0  66.1    -7.3      M    M
  5500   16.0  60.8   275    3    1   5.9   3.2   18.7  65.7    -7.8      M    M

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

           08/27/2014 at 0900 MDT          |       08/27/2014 at 1200 MDT
                                           |
K index... +28.5  LI... +0.7               | K index... +23.6  LI... -2.1
CAPE... +0.2  CIN... -36.0                 | CAPE... +210.8  CIN... -25.4
                                           |
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 -64.0 -83.2  230  45 23   0.6   0.3 | -63.9 -83.0  230  39 20   0.8   0.5
 45000 -61.2 -78.2  225  55 28   4.9   2.7 | -60.7 -77.3  225  52 27   5.2   2.9
 40000 -53.5 -64.3  210  44 23   7.6   4.2 | -52.6 -62.7  215  51 26   6.8   3.7
 38000 -48.9 -56.0  205  41 21   7.6   4.2 | -48.5 -55.3  210  49 25   6.8   3.7
 36000 -44.3 -47.7  205  38 20   7.6   4.2 | -44.5 -48.1  205  46 24   6.7   3.7
 34000 -39.6 -39.3  200  40 20   7.9   4.3 | -39.2 -38.6  205  45 23   7.9   4.3
 32000 -34.3 -29.7  200  42 22   7.8   4.3 | -34.5 -30.1  210  43 22   7.9   4.3
 30000 -29.6 -21.3  205  43 22   7.9   4.3 | -29.7 -21.5  210  42 22   8.0   4.4
 29000 -27.2 -17.0  205  43 22   7.9   4.3 | -27.3 -17.1  210  42 21   8.0   4.4
 28000 -24.9 -12.8  210  43 22   6.8   3.7 | -24.9 -12.8  210  41 21   6.9   3.8
 27000 -23.1  -9.6  210  38 20   6.1   3.3 | -23.1  -9.6  210  40 21   6.2   3.4
 26000 -21.2  -6.2  210  33 17   6.1   3.3 | -21.2  -6.2  210  39 20   6.2   3.4
 25000 -19.4  -2.9  215  29 15   6.0   3.3 | -19.4  -2.9  210  38 20   6.1   3.4
 24000 -17.2   1.0  215  27 14   7.9   4.3 | -17.5   0.5  210  35 18   6.4   3.5
 23000 -14.9   5.2  215  26 14   7.9   4.3 | -15.6   3.9  210  31 16   6.4   3.5
 22000 -12.5   9.5  215  26 13   7.9   4.3 | -13.7   7.3  215  26 14   6.4   3.5
 21000 -10.5  13.1  220  23 12   6.9   3.8 | -11.8  10.8  220  24 12   6.5   3.6
 20000  -8.6  16.5  225  19 10   7.2   4.0 |  -9.9  14.2  225  22 11   6.6   3.6
 19500  -7.6  18.3  230  18  9   7.5   4.1 |  -9.0  15.8  230  21 11   6.7   3.7
 19000  -6.7  19.9  235  16  8   5.4   3.0 |  -8.0  17.6  230  20 10   7.2   4.0
 18500  -6.0  21.2  240  15  8   4.9   2.7 |  -7.0  19.4  235  19 10   7.4   4.0
 18000  -5.3  22.5  245  14  7   4.8   2.6 |  -5.9  21.4  235  19 10   7.4   4.1
 17500  -4.6  23.7  250  14  7   4.5   2.5 |  -4.9  23.2  240  18  9   7.5   4.1
 17000  -4.0  24.8  255  13  7   4.5   2.5 |  -3.8  25.2  240  17  9   7.5   4.1
 16500  -3.3  26.1  260  12  6   5.5   3.0 |  -2.2  28.0  245  16  8   6.8   3.8
 16000  -2.1  28.2  265  12  6   5.9   3.2 |  -1.2  29.8  245  15  8   7.1   3.9
 15500  -1.3  29.7  270  12  6   5.0   2.8 |  -0.4  31.3  250  14  7   4.7   2.6
 15000  -0.5  31.1  275  13  7   5.0   2.8 |   0.3  32.5  255  14  7   4.8   2.6
 14500   0.2  32.4  280  13  7   5.3   2.9 |   1.0  33.8  260  15  7   4.8   2.6
 14000   1.0  33.8  285  14  7   5.4   3.0 |   1.7  35.1  265  15  8   4.9   2.7
 13500   1.7  35.1  285  14  7   5.7   3.1 |   2.4  36.3  270  15  8   5.8   3.2
 13000   2.6  36.7  290  14  7   6.0   3.3 |   3.4  38.1  275  15  8   6.9   3.8
 12500   3.5  38.3  295  14  7   6.0   3.3 |   4.5  40.1  280  16  8   7.2   4.0
 12000   4.3  39.7  295  14  7   5.8   3.2 |   5.6  42.1  285  17  9   7.8   4.3
 11500   5.1  41.2  300  15  7   5.9   3.2 |   6.8  44.2  290  18 10   7.7   4.2
 11000   6.0  42.8  300  15  8   5.9   3.3 |   7.8  46.0  295  19 10   7.2   4.0
 10500   6.8  44.2  305  15  8   4.5   2.5 |   8.9  48.0  295  20 10   4.5   2.4
 10250   7.1  44.8  305  15  8   4.4   2.4 |   9.0  48.2  295  20 10   3.0   1.7
 10000   7.6  45.7  305  15  8   8.2   4.5 |   9.4  48.9  295  20 10   7.2   4.0
  9750   8.2  46.8  305  15  8   9.5   5.2 |   9.9  49.8  295  19 10   8.2   4.5
  9500   8.9  48.0  305  15  8   8.1   4.5 |  10.4  50.7  300  18  9   6.2   3.4
  9250   9.4  48.9  305  15  8   6.1   3.3 |  10.7  51.3  300  17  9   3.0   1.6
  9000   9.9  49.8  310  15  8   6.9   3.8 |  10.9  51.6  300  16  8   4.2   2.3
  8750  10.5  50.9  310  16  8   8.3   4.5 |  11.2  52.2  300  13  7   5.3   2.9
  8500  11.1  52.0  310  16  8   7.2   4.0 |  11.6  52.9  305  11  6   5.7   3.1
  8250  11.5  52.7  315  15  8   6.5   3.5 |  11.9  53.4  305   8  4   6.1   3.3
  8000  12.0  53.6  315  15  8   6.6   3.6 |  12.3  54.1  315   6  3   7.2   4.0
  7750  12.5  54.5  320  14  7   6.5   3.6 |  12.9  55.2  325   4  2   9.3   5.1
  7500  12.9  55.2  320  14  7   4.4   2.4 |  13.5  56.3  330   4  2   9.9   5.4
  7250  13.1  55.6  325  12  6   3.4   1.8 |  14.3  57.7  330   4  2  10.1   5.5
  7000  13.3  55.9  325  10  5   2.4   1.3 |  15.0  59.0  335   4  2   9.9   5.5
  6750  13.4  56.1  330   9  4   3.6   2.0 |  15.7  60.3  335   4  2  10.1   5.5
  6500  13.8  56.8  330   7  4   8.2   4.5 |  16.5  61.7  335   4  2  10.5   5.7
  6250  14.5  58.1  335   6  3   9.1   5.0 |  17.3  63.1  335   4  2  10.4   5.7
  6000  15.1  59.2  335   5  2   9.4   5.2 |  18.1  64.6  335   4  2  10.9   6.0
  5750  15.9  60.6  340   4  2  13.0   7.2 |  19.1  66.4  335   4  2  16.6   9.1
  5500  17.0  62.6  340   4  2  16.8   9.2 |  20.6  69.1  340   4  2  24.3  13.3

           08/27/2014 at 1500 MDT          |       08/27/2014 at 1800 MDT
                                           |
K index... +23.1  LI... -3.6               | K index... +28.7  LI... -3.0
CAPE... +563.4  CIN... -7.0                | CAPE... +382.8  CIN... -7.6
                                           |
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 -62.3 -80.1  225  33 17   1.4   0.8 | -61.7 -79.1  225  28 14   1.1   0.6
 45000 -59.0 -74.2  220  46 24   4.2   2.3 | -58.6 -73.5  220  41 21   4.4   2.4
 40000 -52.3 -62.1  215  52 27   6.5   3.6 | -51.7 -61.1  215  51 26   6.2   3.4
 38000 -48.4 -55.1  215  51 26   6.5   3.6 | -48.0 -54.4  215  50 26   6.2   3.4
 36000 -44.5 -48.1  210  50 26   6.5   3.6 | -44.3 -47.7  215  48 25   6.2   3.4
 34000 -39.6 -39.3  210  47 24   7.6   4.2 | -39.8 -39.6  215  46 24   6.8   3.7
 32000 -35.0 -31.0  210  44 23   7.5   4.1 | -35.7 -32.3  220  44 23   6.7   3.7
 30000 -30.1 -22.2  210  43 22   8.3   4.6 | -31.0 -23.8  220  43 22   8.1   4.4
 29000 -27.6 -17.7  210  43 22   8.3   4.6 | -28.6 -19.5  220  42 22   8.1   4.4
 28000 -25.1 -13.2  210  43 22   7.1   3.9 | -26.2 -15.2  220  42 21   7.5   4.1
 27000 -23.3  -9.9  210  42 22   6.0   3.3 | -24.2 -11.6  220  41 21   6.7   3.7
 26000 -21.6  -6.9  215  41 21   6.0   3.3 | -22.2  -8.0  225  40 21   6.7   3.7
 25000 -19.8  -3.6  215  40 21   6.0   3.3 | -20.2  -4.4  225  40 20   6.8   3.7
 24000 -17.9  -0.2  215  38 20   6.5   3.6 | -18.3  -0.9  225  39 20   6.3   3.5
 23000 -16.0   3.2  215  35 18   6.6   3.6 | -16.5   2.3  225  38 19   6.3   3.5
 22000 -14.1   6.6  215  33 17   6.6   3.6 | -14.6   5.7  225  37 19   6.4   3.5
 21000 -12.2  10.0  220  30 16   6.1   3.3 | -12.8   9.0  230  34 18   6.1   3.4
 20000 -10.4  13.3  220  28 14   6.1   3.3 | -11.0  12.2  230  31 16   6.2   3.4
 19500  -9.5  14.9  220  27 14   6.0   3.3 | -10.1  13.8  235  30 15   6.2   3.4
 19000  -8.6  16.5  220  26 13   6.8   3.7 |  -9.2  15.4  235  28 15   6.3   3.5
 18500  -7.6  18.3  225  25 13   6.9   3.8 |  -8.3  17.1  235  26 13   6.4   3.5
 18000  -6.5  20.3  225  25 13   7.0   3.8 |  -7.4  18.7  235  23 12   6.4   3.5
 17500  -5.5  22.1  225  24 12   7.0   3.9 |  -6.5  20.3  240  21 11   5.8   3.2
 17000  -4.0  24.8  230  23 12   7.0   3.9 |  -5.3  22.5  240  17  9   5.9   3.3
 16500  -2.9  26.8  235  23 12   6.9   3.8 |  -4.4  24.1  245  16  8   6.5   3.6
 16000  -1.9  28.6  235  22 11   6.9   3.8 |  -3.4  25.9  245  15  8   6.4   3.5
 15500  -0.9  30.4  240  21 11   7.0   3.9 |  -2.4  27.7  245  14  7   7.6   4.1
 15000   0.1  32.2  245  20 10   7.1   3.9 |  -1.3  29.7  245  14  7   7.6   4.2
 14500   1.1  34.0  250  18  9   6.6   3.6 |  -0.2  31.6  240  13  7   7.7   4.2
 14000   1.9  35.4  250  17  9   6.6   3.6 |   0.9  33.6  240  13  6   7.8   4.3
 13500   2.8  37.0  255  15  8   6.9   3.8 |   2.1  35.8  240  12  6   7.9   4.3
 13000   3.8  38.8  260  14  7   7.2   4.0 |   3.2  37.8  240  11  6   8.0   4.4
 12500   4.9  40.8  265  14  7   7.4   4.0 |   4.4  39.9  240  11  5   7.9   4.3
 12000   5.9  42.6  270  14  7   7.7   4.2 |   5.5  41.9  240  10  5   7.5   4.1
 11500   7.0  44.6  275  13  7   7.6   4.2 |   6.6  43.9  245   9  5   7.6   4.1
 11000   8.1  46.6  275  13  7   7.2   3.9 |   7.7  45.9  250   7  3   7.4   4.1
 10500   9.1  48.4  275  12  6   4.1   2.3 |   8.8  47.8  250   4  2   4.0   2.2
 10250   9.3  48.7  280  12  6   5.2   2.9 |   9.0  48.2  250   4  2   5.9   3.3
 10000  10.0  50.0  275  11  6  10.4   5.7 |   9.7  49.5  260   3  1  12.2   6.7
  9750  10.7  51.3  275  10  5   9.9   5.5 |  10.4  50.7  275   2  1  11.2   6.2
  9500  11.4  52.5  275   9  4   8.3   4.5 |  11.2  52.2  300   2  1  10.2   5.6
  9250  11.8  53.2  280   7  4   5.5   3.0 |  11.8  53.2  310   2  1   8.1   4.4
  9000  12.2  54.0  280   5  3   7.7   4.2 |  12.5  54.5  315   2  1   9.7   5.3
  8750  12.8  55.0  290   4  2   9.2   5.1 |  13.3  55.9  320   2  1  11.0   6.0
  8500  13.4  56.1  315   2  1   9.2   5.0 |  14.1  57.4  325   2  1  10.3   5.7
  8250  14.1  57.4  320   2  1   9.6   5.3 |  14.8  58.6  330   2  1  10.2   5.6
  8000  14.8  58.6  320   2  1   9.8   5.4 |  15.6  60.1  330   2  1   9.9   5.4
  7750  15.5  59.9  325   2  1  10.0   5.5 |  16.3  61.3  330   2  1   9.6   5.2
  7500  16.3  61.3  325   2  1  10.0   5.5 |  17.0  62.6  335   2  1  10.0   5.5
  7250  17.0  62.6  330   2  1  10.1   5.5 |  17.8  64.0  335   3  1  10.5   5.8
  7000  17.8  64.0  330   2  1   9.8   5.4 |  18.5  65.3  335   3  1   9.8   5.4
  6750  18.5  65.3  330   2  1  10.0   5.5 |  19.2  66.6  335   3  1   9.1   5.0
  6500  19.3  66.7  330   2  1  10.9   6.0 |  20.0  68.0  335   3  1  10.0   5.5
  6250  20.1  68.2  330   2  1  11.7   6.4 |  20.7  69.3  335   3  2  10.9   6.0
  6000  20.9  69.6  335   2  1   9.7   5.3 |  21.5  70.7  335   3  2   9.5   5.2
  5750  21.7  71.1  335   2  1  14.2   7.8 |  22.2  72.0  335   3  2  10.7   5.9
  5500  23.2  73.8  345   2  1  27.1  14.9 |  23.1  73.6  340   3  2  15.9   8.7
________________________________________________________________________________

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



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