Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14

000
UXUS97 KPUB 281228
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0627 MDT Tuesday, April 28, 2015

This forecast is for Tuesday, April 28, 2015:

If the trigger temperature of 42.3 F/5.7 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 326 ft/min (1.7 m/s)
   Maximum height of thermals.................. 13602 ft MSL (6432 ft AGL)

Forecast maximum temperature................... 55.0 F/13.2 C
Time of trigger temperature.................... 0945 MDT
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................. 12536 ft MSL (5365 ft AGL)
Thermal soaring outlook for Wednesday 04/29.... Fair

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

Remarks...

Sunrise/Sunset.................... 06:05:08 / 19:47:40 MDT
Total possible sunshine........... 13 hr 42 min 32 sec (822 min 32 sec)
Altitude of sun at 12:56:34 MDT... 65.27 degrees

Upper air data from numerical model forecast valid on 04/28/2015 at 0600 MDT

Freezing level.................. 7296 ft MSL (126 ft AGL)
Additional freezing level....... 7764 ft MSL (594 ft AGL)
Convective condensation level... 15295 ft MSL (8125 ft AGL)
Lifted condensation level....... 14808 ft MSL (7638 ft AGL)
Lifted index.................... +0.8
K index......................... -19.7

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  -58.4 -73.1   010   38   19   2.3   1.3      M     M       M      M    M
 45000  -55.1 -67.2   015   43   22   0.0   0.0      M     M       M      M    M
 40000  -54.7 -66.5   020   44   23   0.2   0.1      M     M       M      M    M
 38000  -54.2 -65.6   020   41   21   1.5   0.8      M     M       M      M    M
 36000  -53.1 -63.6   020   35   18   1.5   0.8      M     M       M      M    M
 34000  -51.5 -60.7   015   30   15   5.6   3.1      M     M       M      M    M
 32000  -48.1 -54.6   015   25   13   5.7   3.1      M     M       M      M    M
 30000  -44.5 -48.1   015   20   10   6.6   3.6   25.7  78.2     9.9      M    M
 29000  -42.6 -44.7   010   16    8   6.6   3.6   24.4  75.9     9.0      M    M
 28000  -40.6 -41.1   005   13    7   6.6   3.6   23.2  73.8     8.2      M    M
 27000  -38.5 -37.3   355   11    6   7.9   4.3   22.2  72.0     7.5      M    M
 26000  -36.1 -33.0   360   12    6   8.3   4.6   21.6  70.9     7.1      M    M
 25000  -33.6 -28.5   360   13    7   8.3   4.6   21.1  69.9     6.7      M    M
 24000  -31.1 -24.0   360   14    7   8.5   4.7   20.7  69.2     6.4      M    M
 23000  -27.8 -18.0   010   15    8   8.7   4.8   20.1  68.2     6.1      M    M
 22000  -25.2 -13.4   015   16    8   8.7   4.8   19.8  67.6     5.9      M    M
 21000  -22.9  -9.2   020   16    8   6.6   3.6   19.2  66.5     5.4      M    M
 20000  -20.9  -5.6   025   13    6   6.7   3.7   18.1  64.5     4.5      M    M
 19500  -19.9  -3.8   030   11    6   6.7   3.7   17.5  63.6     4.0      M    M
 19000  -18.9  -2.0   040   10    5   6.7   3.7   17.1  62.7     3.6      M    M
 18500  -17.7   0.1   045    9    4   8.5   4.6   16.7  62.1     3.4      M    M
 18000  -16.5   2.3   045    8    4   8.4   4.6   16.5  61.7     3.2      M    M
 17500  -15.2   4.6   050    7    4   8.0   4.4   16.3  61.3     3.1      M    M
 17000  -14.0   6.8   045    7    4   8.0   4.4   15.9  60.7     2.8      M    M
 16500  -12.8   9.0   040    8    4   7.7   4.2   15.7  60.2     2.6      M    M
 16000  -11.7  10.9   040    8    4   6.7   3.7   15.2  59.4     2.2      M    M
 15500  -10.7  12.7   035    9    5   6.6   3.6   14.7  58.5     1.8      M    M
 15000   -9.6  14.7   035   10    5   8.5   4.7   14.4  57.9     1.5      M    M
 14500   -8.3  17.1   035   10    5   8.7   4.8   14.1  57.4     1.3      M    M
 14000   -7.3  18.9   035   10    5   4.1   2.3   13.7  56.6     0.8      M    M
 13500   -6.8  19.8   035   10    5   4.2   2.3   12.7  54.9    -0.1    423  2.1
 13000   -6.4  20.5   030   10    5  -0.1  -0.0   11.6  52.9    -1.2    397  2.0
 12500   -6.6  20.1   025    9    4  -1.2  -0.7    9.9  49.8    -2.9    389  2.0
 12000   -6.7  19.9   015    7    4   2.0   1.1    8.4  47.0    -4.4    376  1.9
 11750   -6.6  20.1   015    7    3   1.8   1.0    7.7  45.9    -5.0    365  1.9
 11500   -6.5  20.3   015    6    3   1.3   0.7    7.1  44.8    -5.7    355  1.8
 11250   -6.4  20.5   010    5    3   2.3   1.3    6.5  43.6    -6.4    346  1.8
 11000   -6.1  21.0   010    5    2   5.8   3.2    6.0  42.8    -6.9    331  1.7
 10750   -5.7  21.7   010    5    2   6.5   3.5    5.8  42.4    -7.1    309  1.6
 10500   -5.3  22.5   010    4    2   5.2   2.8    5.4  41.8    -7.5    290  1.5
 10250   -4.9  23.2   010    4    2   5.9   3.2    5.1  41.2    -7.9    271  1.4
 10000   -4.4  24.1   010    3    2   6.8   3.7    4.8  40.7    -8.2    250  1.3
  9750   -3.9  25.0   015    3    2   6.5   3.6    4.6  40.3    -8.4    228  1.2
  9500   -3.2  26.2   030    3    2   6.2   3.4    3.9  39.1    -9.2    190  1.0
  9250   -2.6  27.3   025    3    2   8.1   4.4    3.8  38.8    -9.4    167  0.8
  9000   -2.1  28.2   025    4    2   7.7   4.2    3.6  38.5    -9.6    142  0.7
  8750   -1.5  29.3   025    4    2   6.8   3.7    3.4  38.2    -9.8    119  0.6
  8500   -1.1  30.0   020    4    2   5.7   3.2    3.2  37.7   -10.1     98  0.5
  8250   -0.7  30.7   010    4    2   5.1   2.8    2.8  37.1   -10.5     79  0.4
  8000   -0.3  31.5   360    4    2   6.9   3.8    2.5  36.5   -10.8     60  0.3
  7750    0.2  32.4   350    5    2   5.6   3.1    2.3  36.2   -11.1     37  0.2
  7500    0.3  32.5   335    5    3  -4.5  -2.5    1.7  35.0   -11.8     28  0.1
  7250   -0.3  31.5   320    6    3  -5.2  -2.8    0.4  32.8   -13.1     37  0.2
  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 * * * * * *

           04/28/2015 at 0900 MDT          |       04/28/2015 at 1200 MDT
                                           |
K index... -22.3  LI... +276.5             | K index... -19.8  LI... +276.6
CAPE... 0.0  CIN... M                      | 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 -59.1 -74.4  010  39 20   2.7   1.5 | -59.5 -75.1  010  35 18   3.1   1.7
 45000 -55.2 -67.4  010  44 22   0.6   0.3 | -55.0 -67.0  015  40 21   0.6   0.3
 40000 -53.9 -65.0  025  47 24   0.8   0.5 | -53.7 -64.7  020  46 24   0.9   0.5
 38000 -53.2 -63.8  025  47 24   1.3   0.7 | -52.6 -62.7  025  49 25   2.2   1.2
 36000 -52.4 -62.3  030  46 23   1.3   0.7 | -51.3 -60.3  030  52 27   2.2   1.2
 34000 -51.0 -59.8  030  43 22   4.8   2.6 | -49.8 -57.6  035  52 27   3.6   2.0
 32000 -48.1 -54.6  035  40 21   4.9   2.7 | -47.6 -53.7  035  42 21   3.6   2.0
 30000 -44.6 -48.3  035  36 19   7.9   4.3 | -44.7 -48.5  035  35 18   7.8   4.3
 29000 -42.3 -44.1  030  33 17   7.9   4.3 | -42.3 -44.1  035  36 18   7.9   4.3
 28000 -39.9 -39.8  030  30 16   7.9   4.3 | -39.9 -39.8  035  36 19   7.9   4.3
 27000 -37.6 -35.7  025  27 14   7.2   3.9 | -37.5 -35.5  035  37 19   8.4   4.6
 26000 -35.5 -31.9  025  23 12   7.0   3.8 | -34.3 -29.7  035  34 18   8.5   4.7
 25000 -33.4 -28.1  020  19 10   7.0   3.8 | -31.8 -25.2  030  32 17   8.5   4.7
 24000 -30.7 -23.3  020  15  8   8.3   4.6 | -29.4 -20.9  030  29 15   6.3   3.5
 23000 -28.3 -18.9  020  15  8   8.2   4.5 | -27.4 -17.3  030  24 12   6.6   3.6
 22000 -25.8 -14.4  015  15  8   8.2   4.5 | -25.5 -13.9  025  18 10   6.7   3.7
 21000 -23.4 -10.1  020  13  7   7.8   4.3 | -23.3  -9.9  020  14  7   8.2   4.5
 20000 -21.1  -6.0  025  11  5   7.9   4.3 | -20.8  -5.4  015  11  6   8.2   4.5
 19500 -19.9  -3.8  025   9  5   7.9   4.3 | -19.6  -3.3  010  10  5   8.2   4.5
 19000 -18.7  -1.7  030   8  4   7.9   4.3 | -18.4  -1.1  005   8  4   8.2   4.5
 18500 -17.5   0.5  035   7  4   8.5   4.7 | -17.1   1.2  360   7  4   8.3   4.5
 18000 -16.2   2.8  040   6  3   8.6   4.7 | -15.9   3.4  360   7  4   8.4   4.6
 17500 -14.9   5.2  040   6  3   8.1   4.5 | -14.6   5.7  360   7  3   7.8   4.3
 17000 -13.6   7.5  040   6  3   8.1   4.5 | -13.5   7.7  360   7  4   7.7   4.2
 16500 -12.4   9.7  040   6  3   7.6   4.2 | -12.3   9.9  360   7  4   7.4   4.0
 16000 -11.4  11.5  045   7  4   6.5   3.6 | -11.3  11.7  360   7  3   6.6   3.6
 15500 -10.4  13.3  045   7  4   6.5   3.6 | -10.3  13.5  005   6  3   6.6   3.6
 15000  -9.2  15.4  050   8  4   8.8   4.8 |  -9.1  15.6  010   6  3   8.7   4.8
 14500  -8.0  17.6  050  10  5   8.8   4.8 |  -7.9  17.8  020   7  4   8.8   4.8
 14000  -6.8  19.8  045  10  5   6.9   3.8 |  -6.8  19.8  025   8  4   5.3   2.9
 13500  -5.8  21.6  040  10  5   7.4   4.1 |  -6.0  21.2  020   8  4   5.7   3.1
 13000  -5.1  22.8  035   9  5  -0.3  -0.1 |  -5.4  22.3  015   8  4   1.7   1.9
 12500  -5.4  22.3  025   7  4  -1.5  -0.8 |  -5.3  22.5  010   7  4   1.4   0.8
 12000  -5.6  21.9  020   5  3  -0.7  -0.4 |  -5.2  22.6  010   5  3   0.2   0.1
 11750  -5.7  21.7  020   4  2  -1.0  -0.6 |  -5.2  22.6  020   4  2   0.6   0.3
 11500  -5.8  21.6  020   3  1  -1.4  -0.8 |  -5.3  22.5  035   2  1   0.2   0.1
 11250  -5.9  21.4  015   2  1   0.3   0.2 |  -5.3  22.5  075   1  1   2.4   1.3
 11000  -5.8  21.6  025   1  0   5.1   2.8 |  -5.0  23.0  115   2  1   7.3   4.0
 10750  -5.3  22.5  050   1  0   6.5   3.6 |  -4.4  24.1  130   2  1   8.3   4.5
 10500  -4.9  23.2  070   1  0   5.6   3.1 |  -3.9  25.0  135   3  2   7.2   4.0
 10250  -4.5  23.9  095   1  0   6.3   3.4 |  -3.3  26.1  135   4  2   8.4   4.6
 10000  -4.0  24.8  105   1  0   6.9   3.8 |  -1.9  28.6  140   5  2   9.9   5.5
  9750  -3.1  26.4  110   1  1   6.0   3.3 |  -1.2  29.8  140   5  2  10.1   5.6
  9500  -2.6  27.3  110   1  1   7.3   4.0 |  -0.4  31.3  135   5  3  10.0   5.5
  9250  -2.0  28.4  085   1  1   8.6   4.7 |   0.3  32.5  140   5  3   9.7   5.3
  9000  -1.4  29.5  060   2  1   8.4   4.6 |   1.0  33.8  140   5  3   9.9   5.4
  8750  -0.8  30.6  050   2  1   9.4   5.1 |   1.8  35.2  140   5  3  10.4   5.7
  8500  -0.1  31.8  050   2  1  10.2   5.6 |   2.6  36.7  140   6  3  10.6   5.8
  8250   0.7  33.3  045   2  1  10.5   5.8 |   3.4  38.1  140   6  3  10.8   5.9
  8000   1.4  34.5  045   2  1   9.9   5.4 |   4.1  39.4  140   6  3   9.7   5.3
  7750   2.2  36.0  045   2  1  13.0   7.1 |   5.0  41.0  140   6  3  16.2   8.9
  7500   3.5  38.3  045   3  1  20.1  11.0 |   6.7  44.1  140   6  3  30.7  16.9
  7250   4.7  40.5  045   3  2   8.4   4.6 |   8.6  47.5  135   6  3   7.3   4.0
  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

           04/28/2015 at 1500 MDT          |       04/28/2015 at 1800 MDT
                                           |
K index... +2.5  LI... +275.4              | K index... -1.6  LI... +274.8
CAPE... 0.0  CIN... -0.6                   | CAPE... 0.0  CIN... -0.5
                                           |
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 -59.8 -75.6  005  31 16   3.2   1.8 | -59.6 -75.3  360  32 16   3.4   1.9
 45000 -55.2 -67.4  010  35 18   0.6   0.3 | -54.8 -66.6  005  36 19  -0.2  -0.1
 40000 -53.9 -65.0  020  47 24   0.9   0.5 | -54.7 -66.5  015  47 24   0.1   0.1
 38000 -52.9 -63.2  030  51 26   2.1   1.1 | -53.7 -64.7  030  56 29   2.4   1.3
 36000 -51.6 -60.9  035  57 29   2.1   1.1 | -52.2 -62.0  040  69 36   2.4   1.3
 34000 -49.9 -57.8  040  61 31   4.6   2.5 | -50.1 -58.2  045  76 39   5.6   3.1
 32000 -47.1 -52.8  040  58 30   4.6   2.5 | -46.7 -52.1  040  67 35   5.7   3.1
 30000 -43.8 -46.8  035  54 28   7.4   4.0 | -43.0 -45.4  035  60 31   7.5   4.1
 29000 -41.6 -42.9  040  50 26   7.4   4.1 | -40.2 -40.4  035  57 29   7.5   4.1
 28000 -38.8 -37.8  040  45 23   7.4   4.1 | -37.9 -36.2  035  54 28   7.6   4.1
 27000 -36.5 -33.7  040  42 22   8.4   4.6 | -35.6 -32.1  035  51 26   8.3   4.6
 26000 -34.0 -29.2  040  39 20   8.4   4.6 | -33.1 -27.6  040  48 25   8.3   4.5
 25000 -31.5 -24.7  035  36 19   8.4   4.6 | -30.6 -23.1  045  44 23   8.3   4.5
 24000 -29.0 -20.2  035  34 17   8.0   4.4 | -28.1 -18.6  050  41 21   8.2   4.5
 23000 -26.6 -15.9  035  31 16   8.1   4.4 | -25.6 -14.1  050  37 19   8.2   4.5
 22000 -24.2 -11.6  035  29 15   8.1   4.4 | -23.2  -9.8  045  33 17   8.2   4.5
 21000 -21.9  -7.4  035  25 13   6.9   3.8 | -20.9  -5.6  045  29 15   7.1   3.9
 20000 -19.8  -3.6  030  19 10   7.0   3.8 | -18.7  -1.7  040  24 13   7.2   3.9
 19500 -18.8  -1.8  025  17  9   7.0   3.9 | -17.6   0.3  035  22 12   7.2   3.9
 19000 -17.7   0.1  015  14  7   7.1   3.9 | -16.5   2.3  035  21 11   7.2   3.9
 18500 -16.6   2.1  010  12  6   7.6   4.2 | -15.5   4.1  030  19 10   6.9   3.8
 18000 -15.5   4.1  360  11  6   7.5   4.1 | -14.5   5.9  020  18  9   6.9   3.8
 17500 -14.4   6.1  350  11  6   7.6   4.2 | -13.5   7.7  015  17  9   6.5   3.6
 17000 -13.3   8.1  345  11  6   7.6   4.2 | -12.5   9.5  005  17  9   6.4   3.5
 16500 -12.1  10.2  340  11  6   7.5   4.1 | -11.6  11.1  355  18  9   6.5   3.6
 16000 -11.0  12.2  335  11  6   6.9   3.8 | -10.5  13.1  350  20 10   7.5   4.1
 15500 -10.0  14.0  335  12  6   6.9   3.8 |  -9.4  15.1  345  22 11   7.6   4.2
 15000  -8.9  16.0  330  11  6   7.3   4.0 |  -8.4  16.9  340  23 12   8.0   4.4
 14500  -7.8  18.0  330  11  6   7.2   4.0 |  -6.7  19.9  340  23 12   8.0   4.4
 14000  -6.1  21.0  330  11  6   7.7   4.2 |  -5.7  21.7  340  21 11   6.3   3.4
 13500  -5.0  23.0  330  11  6   7.4   4.1 |  -4.8  23.4  340  18  9   6.3   3.5
 13000  -4.4  24.1  330   9  5   2.4   1.3 |  -3.9  25.0  345  14  7   5.4   3.0
 12500  -4.0  24.8  335   5  3   3.2   1.8 |  -3.1  26.4  345   9  5   4.6   2.5
 12000  -3.6  25.5  340   1  1   3.4   1.8 |  -2.5  27.5  355   4  2   5.0   2.8
 11750  -3.4  25.9  140   1  0   3.4   1.9 |  -2.1  28.2  010   3  2   5.1   2.8
 11500  -3.2  26.2  150   3  1   3.5   1.9 |  -1.7  28.9  040   2  1   5.0   2.7
 11250  -2.9  26.8  150   4  2   6.1   3.3 |  -1.3  29.7  090   2  1   5.7   3.1
 11000  -2.4  27.7  155   5  2   7.7   4.2 |  -0.9  30.4  125   2  1   5.5   3.0
 10750  -1.9  28.6  155   6  3   6.8   3.8 |  -0.6  30.9  140   3  2   4.8   2.6
 10500  -1.4  29.5  160   7  4   7.4   4.1 |  -0.2  31.6  150   4  2   5.0   2.8
 10250  -0.8  30.6  160   8  4   9.6   5.3 |   0.2  32.4  155   5  2   6.8   3.7
 10000  -0.1  31.8  160   8  4  10.5   5.8 |   0.8  33.4  160   5  3   8.3   4.5
  9750   0.7  33.3  160   8  4   9.5   5.2 |   1.3  34.3  165   6  3   8.1   4.5
  9500   1.4  34.5  160   8  4   9.5   5.2 |   1.9  35.4  165   6  3   8.6   4.7
  9250   2.1  35.8  160   8  4   9.7   5.3 |   2.6  36.7  165   7  4   9.5   5.2
  9000   2.8  37.0  160   8  4   9.6   5.3 |   3.3  37.9  165   7  4   9.7   5.3
  8750   3.6  38.5  160   8  4  10.4   5.7 |   4.1  39.4  170   7  4  10.3   5.6
  8500   4.4  39.9  160   9  4  10.8   5.9 |   4.8  40.6  170   7  4  10.4   5.7
  8250   5.2  41.4  160   9  4  10.7   5.8 |   5.6  42.1  170   8  4   9.8   5.4
  8000   5.9  42.6  165   9  5  10.0   5.5 |   6.3  43.3  170   8  4   9.9   5.4
  7750   6.7  44.1  165   9  5  12.8   7.0 |   7.1  44.8  170   8  4   9.7   5.3
  7500   7.8  46.0  160   9  5  14.2   7.8 |   7.8  46.0  170   8  4   9.2   5.0
  7250   8.7  47.7  160   9  5  11.9   6.5 |   8.4  47.1  170   8  4   9.0   4.9
  7000   9.6  49.3  160   9  5  13.9   7.6 |   9.1  48.4  170   8  4   9.1   5.0
  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.