Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14
781
UXUS97 KPUB 181315
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0615 MST Wednesday, January 18, 2017

This forecast is for Wednesday, January 18, 2017:

If the trigger temperature of 47.3 F/8.5 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 309 ft/min (1.6 m/s)
   Maximum height of thermals.................. 11714 ft MSL (4956 ft AGL)

Forecast maximum temperature................... 49.0 F/9.9 C
Time of trigger temperature.................... 1315 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8195 ft MSL (1438 ft AGL)
Thermal soaring outlook for Thursday 01/19..... Fair

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

Remarks...

Sunrise/Sunset.................... 07:14:36 / 17:03:38 MST
Total possible sunshine........... 9 hr 49 min 2 sec (589 min 2 sec)
Altitude of sun at 12:09:30 MST... 30.73 degrees

Upper air data from numerical model forecast valid on 01/18/2017 at 0500 MST

Freezing level.................. 7015 ft MSL (257 ft AGL)
Additional freezing level....... 9729 ft MSL (2971 ft AGL)
Convective condensation level... 21348 ft MSL (14590 ft AGL)
Lifted condensation level....... 18318 ft MSL (11561 ft AGL)
Lifted index.................... +6.0
K index......................... -7.5

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  -58.2 -72.8   250   13    7   3.2   1.7      M     M       M      M    M
 45000  -53.4 -64.1   215    7    4   2.5   1.4      M     M       M      M    M
 40000  -51.6 -60.9   080   10    5   1.1   0.6      M     M       M      M    M
 38000  -51.3 -60.3   070   19   10  -0.2  -0.1      M     M       M      M    M
 36000  -51.4 -60.5   065   32   17  -0.2  -0.1      M     M       M      M    M
 34000  -51.3 -60.3   065   45   23   3.3   1.8      M     M       M      M    M
 32000  -49.0 -56.2   060   51   26   3.9   2.1      M     M       M      M    M
 30000  -46.5 -51.7   060   56   29   6.7   3.7   23.7  74.7    10.9      M    M
 29000  -44.4 -47.9   060   53   27   6.9   3.8   22.5  72.4    10.1      M    M
 28000  -42.4 -44.3   060   51   26   6.9   3.8   21.4  70.5     9.3      M    M
 27000  -39.8 -39.6   060   48   25   7.4   4.1   20.2  68.3     8.5      M    M
 26000  -37.3 -35.1   060   44   22   8.4   4.6   19.5  67.1     8.1      M    M
 25000  -34.8 -30.6   060   39   20   8.4   4.6   19.0  66.2     7.8      M    M
 24000  -32.3 -26.1   065   35   18   8.3   4.6   18.6  65.5     7.5      M    M
 23000  -29.9 -21.8   065   32   16   7.9   4.3   17.9  64.2     7.0      M    M
 22000  -27.6 -17.7   070   29   15   7.9   4.3   17.2  63.0     6.5      M    M
 21000  -25.2 -13.4   070   26   13   7.9   4.3   16.7  62.0     6.1      M    M
 20000  -22.9  -9.2   070   24   12   7.9   4.4   16.0  60.7     5.6      M    M
 19500  -21.7  -7.1   075   22   12   7.9   4.4   15.7  60.2     5.3      M    M
 19000  -20.5  -4.9   075   21   11   7.9   4.4   15.4  59.7     5.1      M    M
 18500  -19.3  -2.7   075   20   10   7.8   4.3   15.1  59.2     4.9      M    M
 18000  -18.2  -0.8   075   19   10   7.5   4.1   14.7  58.5     4.5      M    M
 17500  -17.1   1.2   075   18    9   7.6   4.1   14.4  57.8     4.2      M    M
 17000  -16.0   3.2   075   16    8   7.3   4.0   14.0  57.1     3.9      M    M
 16500  -14.9   5.2   075   14    7   7.4   4.0   13.6  56.4     3.5      M    M
 16000  -13.8   7.2   075   12    6   6.9   3.8   13.2  55.7     3.2      M    M
 15500  -12.8   9.0   070   10    5   6.8   3.7   12.7  54.8     2.8      M    M
 15000  -11.8  10.8   070    8    4   7.0   3.8   12.2  53.9     2.4      M    M
 14500  -10.6  12.9   065    7    3   7.7   4.2   11.8  53.2     2.1      M    M
 14000   -9.5  14.9   065    5    3   7.7   4.2   11.5  52.6     1.8      M    M
 13500   -7.7  18.1   060    3    2   8.1   4.4   11.0  51.9     1.4      M    M
 13000   -6.5  20.3   045    2    1   7.3   4.0   10.8  51.4     1.2      M    M
 12500   -5.5  22.1   020    1    0   6.8   3.7   10.3  50.5     0.7      M    M
 12000   -4.5  23.9   280    1    1   5.9   3.2    9.8  49.6     0.2      M    M
 11750   -4.1  24.6   285    1    1   6.1   3.4    9.5  49.0    -0.1    405  2.1
 11500   -3.6  25.5   290    2    1   5.9   3.2    9.2  48.5    -0.3    384  2.0
 11250   -3.2  26.2   295    2    1   6.5   3.6    8.9  48.0    -0.6    363  1.8
 11000   -2.6  27.3   295    2    1   7.6   4.2    8.7  47.6    -0.8    340  1.7
 10750   -2.1  28.2   295    2    1   7.7   4.2    8.5  47.3    -1.0    315  1.6
 10500   -1.5  29.3   295    2    1   7.7   4.2    8.3  47.0    -1.2    291  1.5
 10250   -0.9  30.4   295    2    1   7.6   4.2    8.2  46.7    -1.3    267  1.4
 10000   -0.4  31.3   295    1    1   6.5   3.6    8.0  46.4    -1.5    243  1.2
  9750    0.0  32.0   295    1    1   7.1   3.9    7.7  45.9    -1.8    222  1.1
  9500    0.6  33.1   295    1    1   8.5   4.6    7.6  45.7    -1.9    197  1.0
  9250    1.2  34.2   300    1    0   7.9   4.3    7.5  45.5    -2.1    172  0.9
  9000    1.8  35.2   305    1    0   6.7   3.7    7.3  45.2    -2.3    148  0.8
  8750    2.2  36.0   315    1    1   6.6   3.6    7.1  44.7    -2.5    127  0.6
  8500    2.8  37.0   310    1    1   8.2   4.5    6.9  44.4    -2.7    103  0.5
  8250    3.3  37.9   310    2    1   5.3   2.9    6.7  44.1    -2.9     79  0.4
  8000    3.5  38.3   310    2    1  -1.3  -0.7    6.1  43.0    -3.5     68  0.3
  7750    3.4  38.1   310    3    2   3.9   2.2    5.3  41.6    -4.3     63  0.3
  7500    4.2  39.6   300    4    2  15.5   8.5    5.4  41.7    -4.3     32  0.2
  7250    4.4  39.9   290    6    3 -23.9 -13.1    5.0  41.0    -4.7     18  0.1
  7000   -0.2  31.6   290    7    3 -94.2 -51.7    0.2  32.4    -9.5    150  0.8
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           01/18/2017 at 0800 MST          |       01/18/2017 at 1100 MST
                                           |
K index... -9.0  LI... +3.3                | K index... -16.0  LI... +3.0
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.6
                                           |
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 -57.4 -71.3  240  11  5   2.6   1.4 | -57.5 -71.5  255  16  8   2.8   1.6
 45000 -53.6 -64.5  245   6  3   2.0   1.1 | -53.2 -63.8  275   8  4   2.3   1.2
 40000 -51.6 -60.9  060  10  5   1.3   0.7 | -51.6 -60.9  055  10  5   1.0   0.5
 38000 -51.1 -60.0  060  18  9   0.3   0.1 | -51.1 -60.0  060  17  9   0.7   0.4
 36000 -50.9 -59.6  060  29 15   0.3   0.2 | -50.7 -59.3  060  25 13   0.7   0.4
 34000 -50.5 -58.9  060  40 21   4.0   2.2 | -50.1 -58.2  060  33 17   3.4   1.9
 32000 -48.2 -54.8  060  45 23   3.8   2.1 | -47.6 -53.7  065  33 17   4.2   2.3
 30000 -45.7 -50.3  055  49 25   6.2   3.4 | -45.1 -49.2  070  33 17   4.5   2.5
 29000 -44.0 -47.2  055  47 24   5.9   3.2 | -43.8 -46.8  075  31 16   4.5   2.5
 28000 -42.2 -44.0  055  46 24   5.9   3.2 | -42.4 -44.3  080  29 15   4.5   2.5
 27000 -40.4 -40.7  055  44 23   5.9   3.2 | -40.7 -41.3  085  27 14   5.1   2.8
 26000 -38.2 -36.8  060  39 20   7.9   4.4 | -38.6 -37.5  090  25 13   7.5   4.1
 25000 -35.8 -32.4  060  33 17   7.9   4.3 | -36.4 -33.5  090  22 12   7.5   4.1
 24000 -33.4 -28.1  065  27 14   7.9   4.3 | -34.2 -29.6  090  20 10   7.5   4.1
 23000 -30.9 -23.6  070  23 12   8.4   4.6 | -31.5 -24.7  095  19 10   9.2   5.1
 22000 -28.4 -19.1  070  20 10   8.4   4.6 | -28.8 -19.8  095  18  9   9.2   5.1
 21000 -25.9 -14.6  075  17  9   8.3   4.6 | -26.0 -14.8  095  17  9   9.0   4.9
 20000 -23.4 -10.1  080  16  8   8.1   4.5 | -23.4 -10.1  100  15  8   8.8   4.8
 19500 -22.2  -8.0  080  15  8   8.1   4.5 | -22.1  -7.8  100  14  7   8.8   4.8
 19000 -21.0  -5.8  080  15  8   8.1   4.5 | -20.8  -5.4  105  14  7   8.7   4.8
 18500 -19.8  -3.6  080  14  7   8.0   4.4 | -19.5  -3.1  105  13  7   8.6   4.7
 18000 -18.7  -1.7  080  14  7   7.1   3.9 | -18.2  -0.8  110  12  6   8.3   4.5
 17500 -17.6   0.3  080  14  7   7.2   3.9 | -17.0   1.4  110  12  6   8.3   4.6
 17000 -16.6   2.1  075  14  7   6.6   3.6 | -15.8   3.6  110  11  6   7.8   4.3
 16500 -15.2   4.6  070  12  6   6.5   3.6 | -14.6   5.7  110  10  5   7.8   4.3
 16000 -14.1   6.6  065  11  6   8.0   4.4 | -13.4   7.9  110  10  5   7.1   3.9
 15500 -12.9   8.8  065   9  5   8.0   4.4 | -12.5   9.5  100   9  4   6.7   3.7
 15000 -11.6  11.1  060   8  4   8.0   4.4 | -11.5  11.3  085   8  4   6.9   3.8
 14500 -10.4  13.3  060   7  3   8.0   4.4 | -10.5  13.1  080   7  4   7.6   4.2
 14000  -9.2  15.4  055   6  3   8.2   4.5 |  -9.3  15.3  070   7  4   7.5   4.1
 13500  -7.9  17.8  045   6  3   8.3   4.6 |  -7.5  18.5  060   6  3   8.4   4.6
 13000  -6.7  19.9  035   6  3   8.0   4.4 |  -6.2  20.8  050   6  3   8.8   4.8
 12500  -5.5  22.1  020   5  3   7.7   4.2 |  -4.8  23.4  045   6  3   9.4   5.2
 12000  -4.5  23.9  005   6  3   5.8   3.2 |  -3.5  25.7  040   7  3   7.4   4.0
 11750  -4.0  24.8  360   6  3   6.2   3.4 |  -2.9  26.8  040   7  4   6.9   3.8
 11500  -3.6  25.5  355   6  3   6.1   3.4 |  -2.4  27.7  035   7  4   6.7   3.7
 11250  -3.1  26.4  350   6  3   6.2   3.4 |  -1.9  28.6  030   7  4   7.2   3.9
 11000  -2.6  27.3  345   6  3   6.6   3.6 |  -1.4  29.5  030   8  4   6.6   3.6
 10750  -2.1  28.2  340   6  3   6.8   3.7 |  -0.9  30.4  025   8  4   5.3   2.9
 10500  -1.6  29.1  340   5  3   6.7   3.7 |  -0.5  31.1  015   8  4   5.2   2.8
 10250  -1.1  30.0  335   5  2   6.6   3.6 |  -0.2  31.6  010   7  4   5.2   2.9
 10000  -0.6  30.9  330   4  2   7.1   3.9 |   0.2  32.4  005   7  4   5.2   2.8
  9750  -0.1  31.8  335   4  2   7.4   4.1 |   0.6  33.1  355   7  4   5.6   3.1
  9500   0.4  32.7  335   4  2   7.2   3.9 |   1.0  33.8  350   7  3   6.0   3.3
  9250   1.0  33.8  340   4  2   7.3   4.0 |   1.5  34.7  345   6  3   5.8   3.2
  9000   1.5  34.7  340   3  2   6.3   3.4 |   1.9  35.4  335   6  3   6.5   3.6
  8750   1.9  35.4  340   3  2   6.2   3.4 |   2.4  36.3  340   6  3   6.6   3.6
  8500   2.4  36.3  340   4  2   7.5   4.1 |   2.9  37.2  335   6  3   6.5   3.6
  8250   2.9  37.2  345   4  2   5.6   3.1 |   3.3  37.9  335   6  3   5.7   3.1
  8000   3.2  37.8  345   4  2   0.7   0.4 |   3.6  38.5  330   7  4   2.5   1.4
  7750   3.2  37.8  345   5  2   2.5   1.4 |   3.7  38.7  325   8  4   2.0   1.1
  7500   3.9  39.0  335   5  3  18.5  10.1 |   3.9  39.0  320   9  4   7.3   4.0
  7250   4.6  40.3  320   6  3 -17.8  -9.8 |   4.3  39.7  310   9  5  -4.0  -2.2
  7000  -0.0  32.0  310   7  4 -99.0 -54.3 |   2.7  36.9  305   7  4 -31.0 -17.0
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           01/18/2017 at 1400 MST          |       01/18/2017 at 1700 MST
                                           |
K index... -18.9  LI... +3.4               | K index... -23.4  LI... +3.1
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... -0.9
                                           |
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 -57.4 -71.3  275  13  7   2.5   1.4 | -57.3 -71.1  270  12  6   2.5   1.4
 45000 -53.6 -64.5  310   7  4   2.2   1.2 | -53.5 -64.3  300   8  4   2.0   1.1
 40000 -51.6 -60.9  020  11  5   1.3   0.7 | -51.9 -61.4  015  15  8   1.1   0.6
 38000 -51.0 -59.8  035  16  8   0.6   0.3 | -51.4 -60.5  025  22 11   0.5   0.3
 36000 -50.6 -59.1  040  24 12   0.6   0.3 | -51.1 -60.0  030  32 17   0.5   0.3
 34000 -50.2 -58.4  045  31 16   1.8   1.0 | -50.7 -59.3  035  41 21   2.0   1.1
 32000 -48.9 -56.0  065  33 17   2.1   1.2 | -49.4 -56.9  050  39 20   2.3   1.3
 30000 -47.5 -53.5  080  37 19   6.9   3.8 | -47.7 -53.9  065  39 20   7.8   4.3
 29000 -45.1 -49.2  080  38 20   7.8   4.3 | -45.2 -49.4  060  36 19   8.3   4.5
 28000 -42.8 -45.0  085  40 21   7.8   4.3 | -42.7 -44.9  060  34 17   8.3   4.5
 27000 -40.5 -40.9  085  41 21   7.7   4.2 | -40.3 -40.5  060  31 16   8.1   4.5
 26000 -38.0 -36.4  085  39 20   8.7   4.8 | -37.5 -35.5  055  29 15   9.7   5.3
 25000 -35.4 -31.7  085  35 18   8.7   4.8 | -34.6 -30.3  055  28 14   9.8   5.4
 24000 -32.1 -25.8  080  30 15   8.7   4.7 | -31.7 -25.1  050  27 14   9.8   5.4
 23000 -29.7 -21.5  080  26 13   8.3   4.5 | -28.7 -19.7  050  27 14   7.3   4.0
 22000 -27.2 -17.0  085  22 11   8.3   4.5 | -26.5 -15.7  050  28 14   7.3   4.0
 21000 -24.7 -12.5  090  18  9   8.2   4.5 | -24.3 -11.7  050  29 15   7.7   4.3
 20000 -22.3  -8.1  090  14  7   8.1   4.4 | -21.9  -7.4  045  24 12   8.1   4.5
 19500 -21.1  -6.0  095  11  6   8.1   4.4 | -20.6  -5.1  045  21 11   8.1   4.5
 19000 -19.8  -3.6  100   9  5   8.1   4.4 | -19.4  -2.9  040  19 10   8.2   4.5
 18500 -18.6  -1.5  105   7  4   8.2   4.5 | -18.2  -0.8  035  16  8   8.4   4.6
 18000 -17.4   0.7  105   6  3   8.5   4.7 | -16.8   1.8  030  14  7   8.8   4.8
 17500 -16.1   3.0  105   4  2   8.6   4.7 | -15.5   4.1  025  12  6   8.8   4.8
 17000 -14.8   5.4  100   2  1   8.3   4.6 | -14.2   6.4  020  12  6   8.5   4.7
 16500 -13.6   7.5  060   1  1   8.3   4.5 | -13.0   8.6  015  12  6   8.5   4.7
 16000 -12.4   9.7  360   2  1   7.5   4.1 | -11.7  10.9  005  13  6   7.9   4.3
 15500 -11.3  11.7  350   3  2   7.0   3.8 | -10.6  12.9  005  14  7   7.4   4.0
 15000 -10.3  13.5  350   5  2   6.6   3.6 |  -9.5  14.9  005  16  8   7.0   3.9
 14500  -9.4  15.1  350   5  3   5.6   3.1 |  -8.6  16.5  005  16  8   5.7   3.1
 14000  -8.6  16.5  350   6  3   5.7   3.1 |  -7.8  18.0  005  15  8   5.7   3.1
 13500  -7.6  18.3  355   6  3   7.2   3.9 |  -6.8  19.8  005  14  7   6.5   3.6
 13000  -6.6  20.1  355   5  3   6.8   3.8 |  -5.9  21.4  005  13  7   6.2   3.4
 12500  -5.4  22.3  355   5  2   9.4   5.1 |  -4.8  23.4  005  11  6   8.6   4.7
 12000  -4.0  24.8  360   4  2   7.3   4.0 |  -3.6  25.5  005   9  5   6.8   3.8
 11750  -3.5  25.7  010   4  2   6.3   3.5 |  -3.1  26.4  360   8  4   6.4   3.5
 11500  -3.1  26.4  010   4  2   5.9   3.3 |  -2.6  27.3  355   7  4   6.5   3.6
 11250  -2.6  27.3  010   3  2   5.9   3.2 |  -2.1  28.2  350   7  3   6.4   3.5
 11000  -2.2  28.0  015   3  2   6.1   3.3 |  -1.6  29.1  345   6  3   6.5   3.6
 10750  -1.7  28.9  020   3  1   6.2   3.4 |  -1.1  30.0  340   5  3   6.3   3.5
 10500  -1.3  29.7  015   3  1   6.1   3.3 |  -0.7  30.7  330   5  3   6.0   3.3
 10250  -0.8  30.6  015   2  1   6.1   3.4 |  -0.2  31.6  315   5  3   6.0   3.3
 10000  -0.4  31.3  010   2  1   6.0   3.3 |   0.2  32.4  305   5  3   5.8   3.2
  9750   0.6  33.1  350   2  1   7.3   4.0 |   0.7  33.3  295   6  3   6.6   3.6
  9500   1.1  34.0  345   2  1   7.2   3.9 |   1.6  34.9  275   6  3   5.8   3.2
  9250   1.7  35.1  340   1  1   7.2   4.0 |   2.0  35.6  265   6  3   6.4   3.5
  9000   2.2  36.0  335   1  1   7.1   3.9 |   2.4  36.3  255   6  3   3.9   2.1
  8750   2.7  36.9  335   1  0   7.4   4.0 |   2.6  36.7  245   6  3   3.4   1.9
  8500   3.2  37.8  305   1  0   7.8   4.3 |   2.9  37.2  235   7  4   5.7   3.1
  8250   3.8  38.8  275   1  0   7.1   3.9 |   3.2  37.8  230   8  4   4.2   2.3
  8000   4.2  39.6  260   1  1   6.3   3.5 |   3.4  38.1  225   8  4   0.8   0.5
  7750   4.4  39.9  260   1  1  -0.6  -0.3 |   3.1  37.6  225   8  4  -8.7  -4.8
  7500   3.7  38.7  250   2  1 -11.8  -6.5 |   1.8  35.2  225   7  3 -20.3 -11.1
  7250   3.0  37.4  245   2  1  12.0   6.6 |   0.6  33.1  230   5  3   0.1   0.0
  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
________________________________________________________________________________

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.