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 8 9 10 11 12 13 14

000
UXUS97 KPUB 261003
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0403 MDT Monday, September 26, 2016

This forecast is for Monday, September 26, 2016:

If the trigger temperature of 61.2 F/16.2 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 540 ft/min (2.7 m/s)
   Maximum height of thermals.................. 13912 ft MSL (6743 ft AGL)

Forecast maximum temperature................... 69.0 F/21.0 C
Time of trigger temperature.................... 1115 MDT
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................. 12195 ft MSL (5026 ft AGL)
Thermal soaring outlook for Tuesday 09/27...... Good

Wave Soaring Index............................. Not available

Remarks...

Sunrise/Sunset.................... 06:50:51 / 18:50:16 MDT
Total possible sunshine........... 11 hr 59 min 25 sec (719 min 25 sec)
Altitude of sun at 12:50:04 MDT... 49.42 degrees

Upper air data from numerical model forecast valid on 09/26/2016 at 0600 MDT

Freezing level.................. 14736 ft MSL (7567 ft AGL)
Convective condensation level... 20253 ft MSL (13084 ft AGL)
Lifted condensation level....... 16843 ft MSL (9674 ft AGL)
Lifted index.................... +4.5
K index......................... -2.1

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  -65.3 -85.5   310   15    8   2.6   1.4      M     M       M      M    M
 45000  -60.6 -77.1   295   17    9   4.6   2.5      M     M       M      M    M
 40000  -53.3 -63.9   320   15    8   5.1   2.8      M     M       M      M    M
 38000  -50.2 -58.4   325   15    8   5.1   2.8      M     M       M      M    M
 36000  -47.2 -53.0   330   16    8   4.8   2.7      M     M       M      M    M
 34000  -42.7 -44.9   320   17    9   7.8   4.3      M     M       M      M    M
 32000  -38.1 -36.6   310   18    9   7.7   4.2      M     M       M      M    M
 30000  -33.5 -28.3   310   19   10   7.5   4.1   36.7  98.0    12.4      M    M
 29000  -31.3 -24.3   315   20   10   7.5   4.1   35.8  96.5    11.9      M    M
 28000  -29.1 -20.4   315   21   11   7.9   4.4   35.1  95.3    11.5      M    M
 27000  -26.5 -15.7   320   21   11   8.4   4.6   34.5  94.1    11.2      M    M
 26000  -24.0 -11.2   320   21   11   8.5   4.6   34.0  93.3    10.9      M    M
 25000  -21.5  -6.7   325   20   11   8.5   4.7   33.6  92.6    10.7      M    M
 24000  -18.5  -1.3   330   19   10   8.0   4.4   32.8  91.1    10.1      M    M
 23000  -16.1   3.0   335   18    9   8.0   4.4   32.2  89.9     9.7      M    M
 22000  -13.7   7.3   345   17    9   7.7   4.2   31.6  88.9     9.3      M    M
 21000  -11.5  11.3   345   16    8   7.6   4.2   30.8  87.4     8.7      M    M
 20000   -9.2  15.4   345   15    8   7.6   4.2   30.1  86.1     8.1      M    M
 19500   -8.1  17.4   345   14    7   7.6   4.2   29.7  85.5     7.9      M    M
 19000   -7.0  19.4   340   13    7   7.4   4.1   29.3  84.8     7.6      M    M
 18500   -5.9  21.4   335   13    6   7.4   4.1   28.9  84.1     7.3      M    M
 18000   -4.7  23.5   330   12    6   8.0   4.4   28.6  83.5     7.0      M    M
 17500   -3.5  25.7   330   12    6   8.2   4.5   28.3  83.0     6.8      M    M
 17000   -2.3  27.9   330   12    6   7.8   4.3   28.1  82.6     6.6      M    M
 16500   -1.4  29.5   335   12    6   4.9   2.7   27.4  81.4     6.1      M    M
 16000   -0.7  30.7   345   14    7   5.4   3.0   26.7  80.0     5.4      M    M
 15500   -0.2  31.6   350   15    8   1.0   0.6   25.6  78.2     4.4      M    M
 15000   -0.1  31.8   355   16    8   0.9   0.5   24.2  75.5     3.1      M    M
 14500    0.0  32.0   355   17    9   0.9   0.5   22.8  73.0     1.7      M    M
 14000    0.1  32.2   355   16    8   1.1   0.6   21.3  70.4     0.4      M    M
 13500    0.3  32.5   355   15    8   2.8   1.5   19.9  67.8    -1.0    527  2.7
 13000    1.0  33.8   350   14    7   5.6   3.1   19.2  66.5    -1.7    491  2.5
 12500    1.7  35.1   350   12    6   5.3   2.9   18.5  65.4    -2.4    453  2.3
 12000    2.5  36.5   345   11    6   6.5   3.6   17.8  64.1    -3.2    416  2.1
 11750    3.0  37.4   340   11    6   7.5   4.1   17.6  63.8    -3.4    393  2.0
 11500    3.5  38.3   340   10    5   6.9   3.8   17.4  63.4    -3.6    371  1.9
 11250    3.9  39.0   340   10    5   5.9   3.2   17.2  62.9    -3.9    350  1.8
 11000    4.4  39.9   335    9    5   5.8   3.2   16.9  62.4    -4.2    330  1.7
 10750    4.8  40.6   335    8    4   6.7   3.7   16.6  61.9    -4.5    308  1.6
 10500    5.3  41.5   335    8    4   6.0   3.3   16.4  61.4    -4.7    286  1.5
 10250    5.7  42.3   330    7    4   4.5   2.5   16.0  60.8    -5.1    267  1.4
 10000    6.0  42.8   320    6    3   3.6   2.0   15.6  60.0    -5.5    250  1.3
  9750    6.8  44.2   295    6    3   5.2   2.8   14.8  58.7    -6.2    212  1.1
  9500    7.1  44.8   280    6    3   2.8   1.5   14.4  57.9    -6.7    196  1.0
  9250    7.3  45.1   265    7    4   2.5   1.4   13.8  56.9    -7.3    183  0.9
  9000    7.5  45.5   250    8    4   3.5   1.9   13.3  55.9    -7.8    170  0.9
  8750    7.7  45.9   250   10    5   2.1   1.1   12.8  55.1    -8.3    156  0.8
  8500    7.7  45.9   240   10    5   0.2   0.1   12.1  53.8    -9.0    147  0.7
  8250    7.8  46.0   235   11    6   0.2   0.1   11.4  52.5    -9.8    139  0.7
  8000    7.8  46.0   230   12    6   2.0   1.1   10.7  51.3   -10.5    131  0.7
  7750    7.7  45.9   230   10    5  -9.3  -5.1    9.9  49.8   -11.3    125  0.6
  7500    6.1  43.0   230    8    4 -33.4 -18.3    7.5  45.6   -13.7    167  0.8
  7250    4.4  39.9   235    5    3  11.0   6.1    5.2  41.3   -16.1    209  1.1
  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 * * * * * *

           09/26/2016 at 0900 MDT          |       09/26/2016 at 1200 MDT
                                           |
K index... -0.4  LI... +280.5              | K index... +3.4  LI... +279.8
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -1.1
                                           |
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 -65.0 -85.0  285  17  9   2.1   1.2 | -65.2 -85.4  285  20 11   2.1   1.1
 45000 -61.0 -77.8  285  21 11   4.3   2.4 | -61.2 -78.2  285  25 13   4.3   2.4
 40000 -54.0 -65.2  300  15  8   5.6   3.1 | -54.1 -65.4  295  21 11   5.8   3.2
 38000 -50.6 -59.1  300  15  8   5.6   3.1 | -50.6 -59.1  290  20 10   5.8   3.2
 36000 -47.2 -53.0  300  16  8   5.4   3.0 | -47.1 -52.8  290  20 10   5.6   3.1
 34000 -42.8 -45.0  300  19 10   7.7   4.2 | -42.6 -44.7  295  21 11   7.7   4.2
 32000 -38.2 -36.8  300  23 12   7.7   4.2 | -38.0 -36.4  300  22 12   7.6   4.2
 30000 -33.7 -28.7  305  24 12   7.4   4.1 | -33.6 -28.5  305  23 12   7.3   4.0
 29000 -31.5 -24.7  305  24 12   7.4   4.1 | -31.4 -24.5  305  23 12   7.3   4.0
 28000 -29.2 -20.6  305  24 12   7.8   4.3 | -29.2 -20.6  305  23 12   7.6   4.2
 27000 -26.8 -16.2  310  23 12   8.1   4.5 | -26.8 -16.2  305  22 12   7.9   4.3
 26000 -24.4 -11.9  315  22 11   8.1   4.5 | -24.5 -12.1  305  22 11   7.9   4.3
 25000 -21.4  -6.5  320  21 11   8.0   4.4 | -21.6  -6.9  310  21 11   8.0   4.4
 24000 -19.0  -2.2  325  20 10   8.0   4.4 | -19.2  -2.6  310  20 10   8.1   4.4
 23000 -16.6   2.1  325  19 10   8.0   4.4 | -16.8   1.8  315  18  9   8.1   4.4
 22000 -14.2   6.4  330  18  9   8.1   4.5 | -14.4   6.1  315  16  8   8.2   4.5
 21000 -11.8  10.8  325  16  8   8.2   4.5 | -11.9  10.6  315  15  8   8.2   4.5
 20000  -9.3  15.3  320  15  8   8.2   4.5 |  -9.5  14.9  315  14  7   8.2   4.5
 19500  -8.1  17.4  320  15  7   8.3   4.6 |  -8.2  17.2  310  14  7   8.0   4.4
 19000  -6.8  19.8  315  14  7   8.8   4.8 |  -7.1  19.2  315  14  7   7.2   3.9
 18500  -5.5  22.1  315  14  7   8.8   4.8 |  -6.1  21.0  315  13  7   7.2   4.0
 18000  -4.2  24.4  315  13  7   7.7   4.2 |  -5.0  23.0  320  13  6   6.6   3.6
 17500  -3.1  26.4  315  13  7   7.4   4.0 |  -4.1  24.6  325  13  7   6.4   3.5
 17000  -2.0  28.4  315  13  7   6.7   3.7 |  -3.1  26.4  330  13  7   6.3   3.5
 16500  -1.3  29.7  325  13  6   4.1   2.3 |  -2.2  28.0  335  13  7   5.9   3.2
 16000  -0.7  30.7  335  13  7   4.4   2.4 |  -1.4  29.5  340  12  6   6.1   3.3
 15500  -0.2  31.6  345  13  7   2.3   1.3 |  -0.6  30.9  345  12  6   4.1   2.2
 15000   0.1  32.2  350  13  7   2.4   1.3 |  -0.0  32.0  340  11  6   4.2   2.3
 14500   0.5  32.9  350  13  7   2.1   1.2 |   0.6  33.1  340  11  6   3.8   2.1
 14000   0.7  33.3  345  12  6   2.1   1.1 |   1.1  34.0  330  10  5   3.7   2.1
 13500   1.0  33.8  340  11  6   3.0   1.7 |   1.6  34.9  325  10  5   4.1   2.3
 13000   1.6  34.9  335   9  5   4.3   2.4 |   2.3  36.1  315   9  5   4.6   2.5
 12500   2.2  36.0  330   8  4   4.4   2.4 |   2.9  37.2  300   9  4   4.4   2.4
 12000   2.9  37.2  330   7  4   6.0   3.3 |   3.6  38.5  305   8  4   5.1   2.8
 11750   3.3  37.9  330   7  4   6.4   3.5 |   4.0  39.2  305   8  4   5.3   2.9
 11500   3.8  38.8  330   7  3   6.3   3.5 |   4.3  39.7  310   8  4   5.1   2.8
 11250   4.2  39.6  335   6  3   6.3   3.5 |   4.7  40.5  315   7  4   4.6   2.5
 11000   4.7  40.5  335   6  3   6.4   3.5 |   5.0  41.0  320   6  3   5.3   2.9
 10750   5.2  41.4  340   6  3   6.2   3.4 |   5.4  41.7  330   6  3   6.1   3.3
 10500   5.6  42.1  340   6  3   6.6   3.6 |   5.9  42.6  345   5  3   7.0   3.9
 10250   6.2  43.2  345   5  3   7.2   4.0 |   6.5  43.7  355   5  3   8.6   4.7
 10000   6.7  44.1  345   5  2   7.3   4.0 |   7.1  44.8  360   5  2   8.8   4.8
  9750   7.8  46.0  350   4  2   6.9   3.8 |   8.5  47.3  010   4  2   9.7   5.3
  9500   8.3  46.9  345   4  2   6.4   3.5 |   9.2  48.6  015   4  2   9.7   5.3
  9250   8.8  47.8  335   3  2   6.0   3.3 |   9.9  49.8  015   4  2   9.8   5.4
  9000   9.3  48.7  320   3  2   7.5   4.1 |  10.6  51.1  020   4  2   9.6   5.3
  8750   9.8  49.6  315   3  2   4.7   2.6 |  11.4  52.5  020   4  2  10.0   5.5
  8500   9.9  49.8  300   4  2   1.3   0.7 |  12.1  53.8  025   4  2  10.5   5.8
  8250  10.0  50.0  285   5  2   1.5   0.8 |  12.9  55.2  025   4  2  10.2   5.6
  8000  10.2  50.4  280   5  3   4.2   2.3 |  13.7  56.7  030   3  2  11.0   6.1
  7750  10.6  51.1  270   5  3   6.6   3.6 |  14.7  58.5  030   3  2  16.9   9.2
  7500  10.9  51.6  265   4  2   1.5   0.8 |  16.2  61.2  035   3  2  24.0  13.2
  7250  11.1  52.0  255   4  2  13.4   7.3 |  17.8  64.0  040   3  2  12.1   6.6
  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

           09/26/2016 at 1500 MDT          |       09/26/2016 at 1800 MDT
                                           |
K index... +7.7  LI... +277.6              | K index... +9.3  LI... +277.2
CAPE... 0.0  CIN... -0.0                   | CAPE... 0.0  CIN... M
                                           |
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 -65.0 -85.0  280  24 12   2.1   1.1 | -65.1 -85.2  290  27 14   2.4   1.3
 45000 -61.2 -78.2  290  25 13   3.6   2.0 | -61.2 -78.2  295  24 12   3.2   1.7
 40000 -54.9 -66.8  310  22 11   6.9   3.8 | -56.0 -68.8  355  16  8   7.9   4.3
 38000 -50.8 -59.4  315  21 11   7.0   3.8 | -51.0 -59.8  015  21 11   7.5   4.1
 36000 -46.6 -51.9  320  20 10   6.9   3.8 | -46.5 -51.7  025  27 14   7.3   4.0
 34000 -42.2 -44.0  320  19 10   7.4   4.1 | -41.6 -42.9  025  25 13   8.4   4.6
 32000 -37.7 -35.9  315  18  9   7.4   4.0 | -36.5 -33.7  025  22 11   8.4   4.6
 30000 -33.3 -27.9  310  18  9   7.3   4.0 | -32.2 -26.0  010  17  9   7.1   3.9
 29000 -31.1 -24.0  310  17  9   7.3   4.0 | -30.0 -22.0  360  15  8   7.1   3.9
 28000 -28.9 -20.0  310  17  9   7.4   4.1 | -27.9 -18.2  345  14  7   7.2   3.9
 27000 -26.7 -16.1  310  18  9   7.6   4.2 | -25.7 -14.3  340  14  7   7.2   4.0
 26000 -24.4 -11.9  310  18  9   7.6   4.2 | -23.6 -10.5  335  14  7   7.2   4.0
 25000 -21.6  -6.9  305  18  9   7.8   4.3 | -21.4  -6.5  330  14  7   7.3   4.0
 24000 -19.2  -2.6  305  17  9   7.9   4.4 | -18.7  -1.7  330  15  8   7.1   3.9
 23000 -16.9   1.6  305  17  9   8.0   4.4 | -16.6   2.1  325  15  8   7.1   3.9
 22000 -14.5   5.9  305  16  8   7.8   4.3 | -14.5   5.9  325  16  8   7.4   4.0
 21000 -12.2  10.0  305  16  8   7.8   4.3 | -12.3   9.9  325  16  8   7.6   4.1
 20000  -9.9  14.2  310  15  8   7.8   4.3 | -10.0  14.0  325  17  9   7.6   4.2
 19500  -8.7  16.3  310  15  8   7.7   4.2 |  -8.9  16.0  325  17  9   7.6   4.2
 19000  -7.7  18.1  315  14  7   6.8   3.8 |  -7.8  18.0  325  17  9   7.4   4.1
 18500  -6.7  19.9  315  14  7   6.9   3.8 |  -6.7  19.9  330  16  8   7.5   4.1
 18000  -5.7  21.7  320  14  7   6.1   3.4 |  -5.7  21.7  335  16  8   6.3   3.4
 17500  -4.8  23.4  325  13  7   5.9   3.3 |  -4.8  23.4  335  15  8   5.9   3.2
 17000  -3.9  25.0  330  13  7   6.0   3.3 |  -4.0  24.8  340  15  8   5.7   3.1
 16500  -3.0  26.6  335  13  6   6.1   3.3 |  -3.2  26.2  340  15  8   5.2   2.8
 16000  -2.2  28.0  335  12  6   6.1   3.4 |  -2.5  27.5  345  16  8   5.3   2.9
 15500  -1.3  29.7  335  13  7   5.4   3.0 |  -1.7  28.9  345  17  9   4.8   2.7
 15000  -0.5  31.1  335  13  7   5.5   3.0 |  -1.1  30.0  345  18  9   4.9   2.7
 14500   0.3  32.5  335  14  7   5.5   3.0 |  -0.4  31.3  350  18  9   5.6   3.0
 14000   1.1  34.0  335  14  7   5.5   3.0 |   0.5  32.9  350  17  9   5.9   3.2
 13500   1.9  35.4  330  15  8   5.1   2.8 |   1.3  34.3  350  16  8   6.1   3.3
 13000   2.6  36.7  335  13  7   4.6   2.5 |   2.2  36.0  355  13  7   6.3   3.5
 12500   3.2  37.8  340  11  6   3.8   2.1 |   3.1  37.6  360  10  5   6.4   3.5
 12000   3.9  39.0  360   8  4   7.4   4.1 |   4.2  39.6  015   8  4   7.4   4.1
 11750   4.4  39.9  010   7  4   7.3   4.0 |   4.7  40.5  020   7  4   7.2   4.0
 11500   4.9  40.8  020   7  4   8.0   4.4 |   5.2  41.4  035   6  3   7.8   4.3
 11250   5.5  41.9  030   7  4   9.0   5.0 |   5.9  42.6  040   6  3   9.3   5.1
 11000   6.2  43.2  030   7  3   9.5   5.2 |   6.6  43.9  045   6  3   9.4   5.2
 10750   6.9  44.4  030   7  3   9.5   5.2 |   7.2  45.0  050   6  3   8.7   4.8
 10500   7.6  45.7  030   7  3   9.9   5.4 |   7.9  46.2  055   6  3   9.2   5.1
 10250   8.4  47.1  030   7  3  10.5   5.7 |   8.6  47.5  055   7  3  10.1   5.5
 10000   9.2  48.6  030   6  3  10.6   5.8 |   9.4  48.9  060   7  3  10.4   5.7
  9750  10.6  51.1  035   6  3   9.2   5.0 |  10.8  51.4  065   7  3   9.0   4.9
  9500  11.4  52.5  035   6  3  10.4   5.7 |  11.5  52.7  065   7  3   9.9   5.5
  9250  12.1  53.8  035   6  3  10.6   5.8 |  12.2  54.0  065   6  3  10.3   5.6
  9000  12.9  55.2  035   6  3   9.7   5.3 |  13.0  55.4  065   6  3   9.3   5.1
  8750  13.6  56.5  040   6  3   9.6   5.3 |  13.7  56.7  065   6  3   9.1   5.0
  8500  14.4  57.9  040   6  3  10.6   5.8 |  14.4  57.9  065   6  3  10.1   5.5
  8250  15.2  59.4  040   6  3  10.2   5.6 |  15.1  59.2  070   6  3  10.1   5.6
  8000  15.9  60.6  040   6  3  10.9   6.0 |  15.9  60.6  070   6  3   9.8   5.4
  7750  16.9  62.4  040   6  3  16.2   8.9 |  16.6  61.9  070   6  3   9.4   5.1
  7500  18.4  65.1  045   6  3  23.1  12.6 |  17.3  63.1  070   6  3  10.0   5.5
  7250  19.8  67.6  045   6  3  11.6   6.3 |  18.0  64.4  070   5  3   8.6   4.7
  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.