Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7

000
UXUS97 KPUB 231025
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0425 MDT Wednesday, April 23, 2014

This forecast is for Wednesday, April 23, 2014:

If the trigger temperature of 58.4 F/14.6 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 116 ft/min (0.6 m/s)
   Maximum height of thermals.................. 10960 ft MSL (3790 ft AGL)

Forecast maximum temperature................... 58.0 F/14.9 C
Time of trigger temperature.................... 1145 MDT
Time of overdevelopment........................ 1500 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 7639 ft MSL (469 ft AGL)
Thermal soaring outlook for Thursday 04/24..... Poor

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... Improving
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 18754 ft MSL (11584 ft AGL)
Wave soaring outlook for Thursday 04/24........ Fair

Remarks...

Sunrise/Sunset.................... 06:11:19 / 19:43:03 MDT
Total possible sunshine........... 13 hr 31 min 44 sec (811 min 44 sec)
Altitude of sun at 12:57:20 MDT... 63.74 degrees

Upper air data from numerical model forecast valid on 04/23/2014 at 0600 MDT

Freezing level.................. 12520 ft MSL (5350 ft AGL)
Convective condensation level... 16533 ft MSL (9363 ft AGL)
Lifted condensation level....... 15003 ft MSL (7833 ft AGL)
Lifted index.................... +2.8
K index......................... +11.7

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  -62.1 -79.8   240   37   19  -1.3  -0.7      M     M       M      M    M
 45000  -64.0 -83.2   230   62   32   2.1   1.1      M     M       M      M    M
 40000  -60.2 -76.4   220   69   36   2.5   1.4      M     M       M      M    M
 38000  -57.4 -71.3   220   70   36   6.0   3.3      M     M       M      M    M
 36000  -53.7 -64.7   215   69   36   6.0   3.3      M     M       M      M    M
 34000  -49.8 -57.6   215   68   35   7.9   4.4      M     M       M      M    M
 32000  -45.0 -49.0   215   65   34   8.0   4.4      M     M       M      M    M
 30000  -40.3 -40.5   220   62   32   7.4   4.1   30.0  85.9    11.9      M    M
 29000  -38.0 -36.4   220   61   32   7.4   4.1   29.0  84.1    11.3      M    M
 28000  -35.8 -32.4   220   60   31   7.4   4.1   28.1  82.5    10.7      M    M
 27000  -33.0 -27.4   220   59   30   7.8   4.3   27.1  80.8    10.1      M    M
 26000  -30.7 -23.3   220   57   29   7.8   4.3   26.3  79.3     9.6      M    M
 25000  -28.4 -19.1   215   56   29   7.8   4.3   25.6  78.0     9.1      M    M
 24000  -26.0 -14.8   215   54   28   7.3   4.0   24.9  76.9     8.7      M    M
 23000  -23.9 -11.0   220   53   28   7.1   3.9   23.9  75.0     7.9      M    M
 22000  -21.8  -7.2   220   53   27   7.1   3.9   23.0  73.4     7.2      M    M
 21000  -19.6  -3.3   220   53   27   7.2   4.0   22.1  71.8     6.5      M    M
 20000  -17.5   0.5   220   55   28   7.2   4.0   21.2  70.1     5.8      M    M
 19500  -16.4   2.5   225   56   29   7.3   4.0   20.8  69.4     5.4      M    M
 19000  -15.4   4.3   225   57   29   7.3   4.0   20.4  68.7     5.1      M    M
 18500  -14.3   6.3   225   58   30   7.7   4.2   20.0  68.0     4.8      M    M
 18000  -13.1   8.4   225   57   29   7.8   4.3   19.7  67.4     4.5      M    M
 17500  -12.0  10.4   225   57   29   7.9   4.3   19.4  66.8     4.2      M    M
 17000  -10.8  12.6   225   56   29   8.1   4.4   19.1  66.3     3.9      M    M
 16500   -9.6  14.7   230   55   28   8.1   4.4   18.8  65.8     3.7      M    M
 16000   -8.4  16.9   230   54   28   8.1   4.5   18.5  65.3     3.4      M    M
 15500   -7.2  19.0   230   53   28   8.1   4.5   18.2  64.8     3.2      M    M
 15000   -6.0  21.2   230   53   27   8.0   4.4   18.0  64.4     3.0      M    M
 14500   -4.8  23.4   235   50   26   7.8   4.3   17.7  63.8     2.7      M    M
 14000   -3.6  25.5   240   48   25   7.8   4.3   17.4  63.2     2.4      M    M
 13500   -2.5  27.5   240   44   23   7.4   4.1   17.0  62.6     2.1      M    M
 13000   -1.4  29.5   240   39   20   7.5   4.1   16.6  61.9     1.7      M    M
 12500   -0.2  31.6   240   35   18   9.5   5.2   16.4  61.5     1.5      M    M
 12000    0.9  33.6   240   31   16   5.0   2.8   16.0  60.8     1.1      M    M
 11750    1.3  34.3   240   29   15   6.6   3.6   15.7  60.3     0.7      M    M
 11500    1.8  35.2   245   29   15   7.6   4.2   15.5  59.9     0.5      M    M
 11250    2.3  36.1   245   29   15   7.5   4.1   15.3  59.6     0.3      M    M
 11000    2.9  37.2   250   29   15   6.9   3.8   15.2  59.3     0.1      M    M
 10750    3.4  38.1   250   30   15   7.7   4.2   14.9  58.9    -0.1    307  1.6
 10500    4.0  39.2   255   29   15   9.0   5.0   14.8  58.7    -0.2    281  1.4
 10250    5.3  41.5   255   27   14   8.9   4.9   14.7  58.5    -0.3    227  1.2
 10000    6.0  42.8   255   26   14   9.4   5.2   14.7  58.4    -0.4    200  1.0
  9750    6.7  44.1   255   26   13   9.7   5.3   14.6  58.3    -0.4    170  0.9
  9500    7.4  45.3   255   25   13   9.6   5.3   14.6  58.3    -0.4    141  0.7
  9250    8.1  46.6   255   25   13   9.7   5.3   14.6  58.3    -0.4    112  0.6
  9000    8.8  47.8   255   24   12   8.5   4.6   14.6  58.3    -0.5     84  0.4
  8750    9.4  48.9   250   23   12   7.1   3.9   14.4  58.0    -0.7     60  0.3
  8500    9.9  49.8   250   22   11   7.7   4.2   14.2  57.6    -0.8     36  0.2
  8250   10.5  50.9   250   21   11   6.2   3.4   14.1  57.3    -1.0     12  0.1
  8000   10.8  51.4   250   20   10   1.0   0.6   13.6  56.5    -1.5      M    M
  7750   10.3  50.5   250   17    9 -17.4  -9.5   12.4  54.4    -2.7      4  0.0
  7500    8.0  46.4   255   11    6 -40.7 -22.3    9.4  48.9    -5.7     66  0.3
  7250    5.7  42.3   265    6    3  -1.1  -0.6    6.4  43.6    -8.8    127  0.6
  7000      M     M     M    M    M     M     M      M     M       M      M    M
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           04/23/2014 at 0900 MDT          |       04/23/2014 at 1200 MDT
                                           |
K index... +0.4  LI... +1.8                | K index... -2.6  LI... +0.9
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  250  37 19  -1.0  -0.6 | -59.5 -75.1  245  34 18  -1.2  -0.6
 45000 -61.8 -79.2  235  68 35   0.9   0.5 | -61.3 -78.3  240  66 34  -1.3  -0.7
 40000 -59.4 -74.9  225  71 36   1.5   0.8 | -58.6 -73.5  225  71 37   1.8   1.0
 38000 -57.1 -70.8  220  73 38   5.5   3.0 | -56.7 -70.1  225  71 36   4.1   2.2
 36000 -53.8 -64.8  215  76 39   5.5   3.0 | -54.2 -65.6  225  68 35   4.1   2.2
 34000 -50.3 -58.5  215  78 40   7.2   3.9 | -51.5 -60.7  225  65 33   7.0   3.9
 32000 -46.0 -50.8  215  73 38   7.2   3.9 | -47.3 -53.1  230  62 32   6.9   3.8
 30000 -41.7 -43.1  215  68 35   7.2   3.9 | -43.1 -45.6  230  59 31   8.0   4.4
 29000 -39.5 -39.1  220  65 34   7.2   3.9 | -40.7 -41.3  235  56 29   8.0   4.4
 28000 -37.3 -35.1  220  62 32   7.2   3.9 | -38.3 -36.9  235  53 28   8.0   4.4
 27000 -34.6 -30.3  225  59 30   8.0   4.4 | -35.3 -31.5  235  50 26   7.9   4.4
 26000 -32.2 -26.0  225  58 30   8.1   4.5 | -32.9 -27.2  235  47 24   7.9   4.3
 25000 -29.7 -21.5  225  56 29   8.1   4.5 | -30.5 -22.9  235  44 23   7.9   4.3
 24000 -27.3 -17.1  225  55 28   7.9   4.4 | -28.1 -18.6  235  41 21   8.0   4.4
 23000 -25.0 -13.0  225  53 27   7.8   4.3 | -25.7 -14.3  235  40 21   8.0   4.4
 22000 -22.6  -8.7  225  52 27   7.8   4.3 | -23.3  -9.9  235  39 20   8.0   4.4
 21000 -20.3  -4.5  225  51 26   7.7   4.2 | -20.9  -5.6  235  38 20   8.0   4.4
 20000 -18.0  -0.4  230  49 25   7.7   4.2 | -18.5  -1.3  235  38 20   8.0   4.4
 19500 -16.8   1.8  230  49 25   7.7   4.2 | -17.3   0.9  235  38 20   8.0   4.4
 19000 -15.7   3.7  230  48 25   7.7   4.2 | -16.1   3.0  235  38 20   7.9   4.4
 18500 -14.5   5.9  230  48 25   7.6   4.2 | -14.9   5.2  235  38 20   7.6   4.2
 18000 -13.4   7.9  230  47 24   7.5   4.1 | -13.8   7.2  240  38 19   7.4   4.0
 17500 -12.3   9.9  235  46 24   7.5   4.1 | -12.7   9.1  240  37 19   7.4   4.1
 17000 -11.2  11.8  235  45 23   7.5   4.1 | -11.8  10.8  240  36 18   5.9   3.2
 16500 -10.1  13.8  240  44 23   7.5   4.1 | -10.9  12.4  245  34 18   6.1   3.3
 16000  -8.9  16.0  240  44 23   7.9   4.4 | -10.0  14.0  245  33 17   5.1   2.8
 15500  -7.7  18.1  240  43 22   8.0   4.4 |  -9.4  15.1  250  29 15   5.0   2.8
 15000  -6.5  20.3  245  43 22   7.7   4.2 |  -8.7  16.3  255  25 13   6.4   3.5
 14500  -5.5  22.1  245  42 22   7.0   3.9 |  -7.6  18.3  255  23 12   8.3   4.6
 14000  -4.4  24.1  245  42 21   6.9   3.8 |  -6.4  20.5  255  20 10   8.6   4.7
 13500  -3.6  25.5  245  39 20   5.4   3.0 |  -5.1  22.8  255  19 10   9.8   5.4
 13000  -2.8  27.0  245  34 18   5.5   3.0 |  -3.6  25.5  255  18 10   9.7   5.3
 12500  -1.9  28.6  245  31 16   8.2   4.5 |  -2.0  28.4  250  18  9  11.9   6.5
 12000  -0.8  30.6  245  27 14   6.2   3.4 |  -0.6  30.9  250  17  9   7.6   4.2
 11750  -0.4  31.3  245  26 13   6.7   3.7 |   0.1  32.2  250  17  9   9.2   5.0
 11500   0.1  32.2  245  26 13   7.2   3.9 |   0.8  33.4  250  17  9  10.3   5.7
 11250   0.6  33.1  250  26 13   7.6   4.2 |   1.6  34.9  250  17  9  10.3   5.6
 11000   1.2  34.2  250  26 13   5.8   3.2 |   2.3  36.1  245  16  8   9.5   5.2
 10750   1.5  34.7  255  26 13   6.2   3.4 |   3.0  37.4  245  16  8   9.1   5.0
 10500   2.1  35.8  255  25 13   8.6   4.7 |   3.7  38.7  245  16  8   9.8   5.4
 10250   3.4  38.1  255  22 12   8.6   4.7 |   5.2  41.4  245  16  8  10.3   5.6
 10000   4.0  39.2  255  21 11   9.4   5.2 |   6.0  42.8  245  15  8  10.6   5.8
  9750   4.7  40.5  255  20 10   9.6   5.3 |   6.7  44.1  245  15  8   9.9   5.4
  9500   5.4  41.7  250  19 10   9.5   5.2 |   7.5  45.5  240  15  8  10.0   5.5
  9250   6.1  43.0  250  18  9   9.4   5.2 |   8.2  46.8  240  15  8  10.0   5.5
  9000   6.8  44.2  250  17  9   9.0   4.9 |   9.0  48.2  240  15  7  10.2   5.6
  8750   7.5  45.5  245  16  8   9.6   5.3 |   9.7  49.5  240  14  7  10.4   5.7
  8500   8.2  46.8  245  14  7  10.4   5.7 |  10.5  50.9  240  14  7  10.3   5.7
  8250   9.0  48.2  240  13  7   9.9   5.4 |  11.3  52.3  240  14  7  10.4   5.7
  8000   9.7  49.5  235  12  6   8.7   4.8 |  12.1  53.8  240  14  7  11.2   6.1
  7750  10.4  50.7  235  11  6  12.0   6.6 |  13.1  55.6  235  13  7  17.9   9.8
  7500  11.5  52.7  230  10  5  19.1  10.5 |  14.8  58.6  235  13  6  27.6  15.2
  7250  12.6  54.7  225   8  4   6.3   3.5 |  16.5  61.7  235  12  6  10.9   6.0
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           04/23/2014 at 1500 MDT          |       04/23/2014 at 1800 MDT
                                           |
K index... +23.5  LI... -1.8               | K index... +23.9  LI... -1.3
CAPE... +147.0  CIN... -1.9                | CAPE... +128.6  CIN... -1.3
                                           |
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 -58.9 -74.0  235  31 16  -1.3  -0.7 | -57.7 -71.9  245  28 15   0.1   0.1
 45000 -60.9 -77.6  235  63 32  -0.0  -0.0 | -57.5 -71.5  245  57 29   0.1   0.0
 40000 -58.7 -73.7  230  70 36   1.5   0.8 | -57.5 -71.5  230  65 34  -0.0  -0.0
 38000 -57.3 -71.1  230  71 37   3.2   1.8 | -57.1 -70.8  225  66 34   1.6   0.9
 36000 -55.4 -67.7  225  70 36   3.2   1.8 | -56.2 -69.2  220  61 32   1.6   0.9
 34000 -53.1 -63.6  225  68 35   8.1   4.4 | -54.9 -66.8  215  57 29   7.8   4.3
 32000 -48.5 -55.3  230  65 34   7.6   4.2 | -50.1 -58.2  220  50 26   8.0   4.4
 30000 -44.0 -47.2  230  61 31   7.7   4.2 | -45.2 -49.4  220  44 23   8.8   4.8
 29000 -41.6 -42.9  230  55 28   7.8   4.3 | -42.6 -44.7  225  43 22   8.7   4.8
 28000 -38.7 -37.7  225  48 25   7.8   4.3 | -39.3 -38.7  225  41 21   8.7   4.8
 27000 -36.4 -33.5  225  43 22   8.0   4.4 | -36.7 -34.1  225  40 21   8.2   4.5
 26000 -33.9 -29.0  225  40 21   8.2   4.5 | -34.4 -29.9  225  38 20   7.7   4.2
 25000 -31.4 -24.5  220  38 19   8.2   4.5 | -32.2 -26.0  225  36 18   7.7   4.2
 24000 -29.0 -20.2  220  35 18   8.0   4.4 | -29.9 -21.8  230  33 17   7.7   4.2
 23000 -26.7 -16.1  225  36 19   7.7   4.2 | -27.5 -17.5  230  31 16   7.8   4.3
 22000 -24.4 -11.9  225  38 20   7.7   4.2 | -25.2 -13.4  230  29 15   7.8   4.3
 21000 -22.1  -7.8  230  39 20   7.0   3.9 | -22.9  -9.2  225  27 14   7.7   4.2
 20000 -20.1  -4.2  235  33 17   6.9   3.8 | -20.6  -5.1  225  25 13   7.6   4.2
 19500 -19.1  -2.4  235  31 16   7.0   3.8 | -19.5  -3.1  225  24 13   7.6   4.2
 19000 -18.1  -0.6  240  28 14   7.0   3.9 | -18.4  -1.1  220  23 12   7.6   4.2
 18500 -17.0   1.4  240  25 13   7.7   4.2 | -17.3   0.9  220  22 12   7.6   4.2
 18000 -15.8   3.6  240  22 11   8.2   4.5 | -16.1   3.0  220  21 11   7.6   4.2
 17500 -14.7   5.5  245  19 10   8.3   4.5 | -15.0   5.0  215  20 11   7.6   4.2
 17000 -13.4   7.9  245  16  8   8.6   4.7 | -13.9   7.0  215  19 10   7.8   4.3
 16500 -12.2  10.0  245  15  7   8.6   4.7 | -12.7   9.1  215  18  9   7.8   4.3
 16000 -10.9  12.4  245  13  7   9.0   4.9 | -11.6  11.1  215  17  9   8.0   4.4
 15500  -9.6  14.7  245  12  6   9.1   5.0 | -10.4  13.3  215  16  8   8.0   4.4
 15000  -8.2  17.2  245  11  6   9.4   5.2 |  -9.3  15.3  210  14  7   8.3   4.5
 14500  -6.8  19.8  240  11  6   9.8   5.4 |  -8.0  17.6  215  13  7   8.8   4.8
 14000  -5.3  22.5  240  11  6   9.8   5.4 |  -6.7  19.9  215  12  6   8.9   4.9
 13500  -3.8  25.2  235  11  6   9.8   5.4 |  -5.2  22.6  215  11  6  10.5   5.7
 13000  -2.4  27.7  230  11  6   9.8   5.4 |  -3.7  25.3  215  11  5  10.2   5.6
 12500  -0.8  30.6  230  11  6  11.5   6.3 |  -2.0  28.4  215  10  5  12.4   6.8
 12000   0.7  33.3  225  11  6   7.9   4.3 |  -0.4  31.3  215  10  5   8.4   4.6
 11750   1.3  34.3  225  11  6   9.3   5.1 |   0.2  32.4  215   9  5   9.8   5.4
 11500   2.0  35.6  220  11  6  10.1   5.5 |   1.0  33.8  215   9  5  10.7   5.9
 11250   2.8  37.0  220  11  6  10.0   5.5 |   1.8  35.2  215   9  5  11.0   6.0
 11000   3.5  38.3  220  11  6   9.6   5.3 |   2.6  36.7  215   9  5   9.3   5.1
 10750   4.2  39.6  220  11  6   9.5   5.2 |   3.3  37.9  215   9  5   8.7   4.8
 10500   5.0  41.0  215  11  6   9.9   5.4 |   4.0  39.2  215   9  4  10.2   5.6
 10250   6.4  43.5  215  11  6  10.1   5.5 |   5.5  41.9  215   8  4  10.0   5.5
 10000   7.2  45.0  215  11  6  10.3   5.6 |   6.3  43.3  215   8  4  10.0   5.5
  9750   8.0  46.4  215  11  5  10.1   5.6 |   7.0  44.6  215   8  4  10.1   5.5
  9500   8.7  47.7  210  11  5  10.1   5.6 |   7.8  46.0  210   8  4  10.1   5.5
  9250   9.5  49.1  210  11  5  10.1   5.6 |   8.5  47.3  210   8  4  10.0   5.5
  9000  10.2  50.4  210  11  5  10.2   5.6 |   9.3  48.7  210   7  4  10.1   5.6
  8750  11.0  51.8  210  11  5  10.2   5.6 |  10.0  50.0  210   7  4  10.2   5.6
  8500  11.8  53.2  205  11  5  10.1   5.6 |  10.8  51.4  210   7  4  10.2   5.6
  8250  12.5  54.5  205  11  5  10.2   5.6 |  11.5  52.7  205   7  3  10.1   5.6
  8000  13.3  55.9  205  11  5  10.9   6.0 |  12.3  54.1  205   6  3   9.7   5.3
  7750  14.3  57.7  205  10  5  17.2   9.4 |  13.0  55.4  205   5  3  10.6   5.8
  7500  15.9  60.6  205  10  5  26.0  14.3 |  13.9  57.0  205   4  2  12.9   7.1
  7250  17.5  63.5  205   9  5  10.9   6.0 |  14.7  58.5  205   3  1   8.8   4.8
  7000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
________________________________________________________________________________

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

The information contained herein is based on rawinsonde observation and/or
numerical weather prediction model data taken near the Air Force Academy
in Colorado Springs, Colorado at

                   North Latitude:  38 deg 58 min 48.000 sec
                   West Longitude: 104 deg 49 min 12.000 sec
                   Elevation: 6572 feet (2003 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.