Soaring Guidance
Issued by NWS Pueblo, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6
000
UXUS97 KPUB 171335
SRGPUB

Soaring Forecast
National Weather Service Pueblo, Colorado
0635 MST Tuesday, January 17, 2017

This forecast is for Tuesday, January 17, 2017:

If the trigger temperature of 43.1 F/6.2 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 118 ft/min (0.6 m/s)
   Maximum height of thermals.................. 10705 ft MSL (3947 ft AGL)

Forecast maximum temperature................... 43.0 F/6.6 C
Time of trigger temperature.................... 1345 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 9007 ft MSL (2250 ft AGL)
Thermal soaring outlook for Wednesday 01/18.... Poor

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

Remarks...

Sunrise/Sunset.................... 07:15:04 / 17:02:33 MST
Total possible sunshine........... 9 hr 47 min 29 sec (587 min 29 sec)
Altitude of sun at 12:09:11 MST... 30.52 degrees

Upper air data from numerical model forecast valid on 01/17/2017 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 13924 ft MSL (7166 ft AGL)
Lifted condensation level....... 11928 ft MSL (5171 ft AGL)
Lifted index.................... +5.5
K index......................... +15.4

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  -59.0 -74.2   260   20   10   2.8   1.5      M     M       M      M    M
 45000  -54.6 -66.3   250   21   11   1.6   0.9      M     M       M      M    M
 40000  -54.2 -65.6   260    4    2   0.2   0.1      M     M       M      M    M
 38000  -54.3 -65.7   040    4    2  -0.7  -0.4      M     M       M      M    M
 36000  -54.7 -66.5   045   12    6  -0.7  -0.4      M     M       M      M    M
 34000  -54.9 -66.8   045   20   10   4.5   2.5      M     M       M      M    M
 32000  -50.9 -59.6   040   17    9   6.8   3.7      M     M       M      M    M
 30000  -46.7 -52.1   040   14    7   8.2   4.5   23.7  74.6    13.4      M    M
 29000  -43.6 -46.5   040   14    7   8.3   4.6   22.8  73.1    13.0      M    M
 28000  -41.1 -42.0   040   13    7   8.3   4.6   22.3  72.2    12.7      M    M
 27000  -38.7 -37.7   045   13    7   8.2   4.5   21.9  71.4    12.5      M    M
 26000  -36.3 -33.3   045   11    6   8.0   4.4   21.1  70.1    12.1      M    M
 25000  -33.9 -29.0   045    9    5   8.0   4.4   20.5  68.9    11.6      M    M
 24000  -31.5 -24.7   050    8    4   8.0   4.4   19.9  67.9    11.3      M    M
 23000  -29.1 -20.4   045    6    3   8.0   4.4   19.2  66.6    10.9      M    M
 22000  -26.7 -16.1   030    5    3   8.0   4.4   18.6  65.5    10.5      M    M
 21000  -24.3 -11.7   010    4    2   7.6   4.2   18.1  64.6    10.1      M    M
 20000  -22.2  -8.0   360    4    2   7.2   4.0   17.1  62.9     9.4      M    M
 19500  -21.1  -6.0   355    4    2   7.2   4.0   16.7  62.1     9.0      M    M
 19000  -20.1  -4.2   350    4    2   7.2   4.0   16.3  61.4     8.7      M    M
 18500  -19.0  -2.2   345    5    2   6.9   3.8   15.9  60.7     8.4      M    M
 18000  -18.1  -0.6   345    5    3   6.0   3.3   15.3  59.6     7.9      M    M
 17500  -17.2   1.0   340    6    3   6.1   3.3   14.7  58.5     7.4      M    M
 17000  -16.3   2.7   345    6    3   6.1   3.3   14.1  57.4     6.9      M    M
 16500  -15.4   4.3   355    6    3   6.1   3.3   13.5  56.3     6.4      M    M
 16000  -14.5   5.9   360    6    3   6.9   3.8   12.9  55.2     5.9      M    M
 15500  -13.3   8.1   360    6    3   7.6   4.2   12.5  54.6     5.6      M    M
 15000  -12.2  10.0   355    6    3   7.3   4.0   12.2  54.0     5.3      M    M
 14500  -10.8  12.6   355    6    3   6.0   3.3   11.3  52.4     4.5      M    M
 14000  -10.0  14.0   355    6    3   5.5   3.0   10.7  51.3     3.9      M    M
 13500   -9.2  15.4   345    6    3   5.2   2.8   10.0  49.9     3.2      M    M
 13000   -8.5  16.7   340    6    3   5.9   3.2    9.2  48.6     2.5      M    M
 12500   -7.5  18.5   330    6    3   6.8   3.7    8.7  47.7     2.0      M    M
 12000   -6.6  20.1   325    7    4   5.2   2.9    8.1  46.6     1.5      M    M
 11750   -6.2  20.8   320    7    4   5.9   3.3    7.8  46.1     1.2      M    M
 11500   -5.8  21.6   310    7    3   5.9   3.2    7.5  45.5     0.9      M    M
 11250   -5.3  22.5   300    7    3   5.8   3.2    7.2  45.0     0.6      M    M
 11000   -4.9  23.2   295    7    3   6.1   3.3    6.9  44.4     0.3      M    M
 10750   -4.5  23.9   285    7    3   5.0   2.8    6.6  43.9    -0.0    317  1.6
 10500   -4.2  24.4   280    7    4   4.0   2.2    6.2  43.1    -0.4    301  1.5
 10250   -3.9  25.0   275    7    4   4.3   2.4    5.7  42.3    -0.9    284  1.4
 10000   -3.6  25.5   265    7    4   3.0   1.6    5.3  41.5    -1.3    268  1.4
  9750   -3.4  25.9   260    7    4   3.5   1.9    4.7  40.5    -1.8    255  1.3
  9500   -3.0  26.6   255    7    4   4.9   2.7    4.3  39.8    -2.2    237  1.2
  9250   -2.7  27.1   250    7    4   4.4   2.4    3.9  39.1    -2.6    220  1.1
  9000   -2.4  27.7   250    7    4   3.7   2.0    3.5  38.3    -3.1    203  1.0
  8750   -2.1  28.2   240    8    4   3.7   2.1    3.0  37.5    -3.5    188  1.0
  8500   -1.8  28.8   235    8    4   5.2   2.9    2.6  36.7    -4.0    171  0.9
  8250   -1.5  29.3   230    8    4   2.1   1.1    2.2  36.0    -4.4    154  0.8
  8000   -1.6  29.1   225    8    4  -3.2  -1.7    1.4  34.6    -5.2    149  0.8
  7750   -1.7  28.9   225    8    4   1.2   0.6    0.5  32.9    -6.1    147  0.7
  7500   -1.5  29.3   220    8    4   2.5   1.4    0.1  32.1    -6.6    132  0.7
  7250   -1.8  28.8   220    8    4 -12.7  -7.0   -0.8  30.6    -7.5    133  0.7
  7000   -3.3  26.1   220    6    3 -27.8 -15.2   -2.6  27.3    -9.2    173  0.9
  6750      M     M     M    M    M     M     M      M     M       M      M    M

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

           01/17/2017 at 0800 MST          |       01/17/2017 at 1100 MST
                                           |
K index... +13.0  LI... +2.9               | K index... +10.0  LI... +2.7
CAPE... 0.0  CIN... -0.4                   | 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 -59.1 -74.4  245  20 10   2.6   1.5 | -59.6 -75.3  245  20 10   2.8   1.6
 45000 -55.0 -67.0  240  20 10   1.2   0.7 | -55.1 -67.2  250  16  8   1.0   0.5
 40000 -55.4 -67.7  105   2  1  -0.3  -0.2 | -56.0 -68.8  115   5  3  -0.6  -0.3
 38000 -55.2 -67.4  065  11  6   1.2   0.7 | -55.9 -68.6  085  14  7   1.0   0.6
 36000 -54.5 -66.1  060  23 12   1.2   0.7 | -55.3 -67.5  075  25 13   1.0   0.6
 34000 -53.6 -64.5  060  34 17   4.9   2.7 | -54.3 -65.7  070  36 19   7.0   3.8
 32000 -50.1 -58.2  055  27 14   5.9   3.2 | -50.0 -58.0  070  36 18   7.3   4.0
 30000 -45.9 -50.6  045  20 10   7.8   4.3 | -45.0 -49.0  070  34 18   7.7   4.2
 29000 -43.6 -46.5  040  18  9   7.8   4.3 | -42.7 -44.9  070  33 17   7.7   4.2
 28000 -41.2 -42.2  040  16  8   7.8   4.3 | -40.4 -40.7  070  31 16   7.7   4.2
 27000 -38.9 -38.0  035  14  7   8.0   4.4 | -38.1 -36.6  075  29 15   7.8   4.3
 26000 -36.4 -33.5  035  12  6   8.3   4.5 | -35.7 -32.3  075  23 12   7.9   4.4
 25000 -34.0 -29.2  040  11  6   8.3   4.6 | -33.3 -27.9  075  18  9   8.0   4.4
 24000 -31.5 -24.7  045   9  5   8.3   4.5 | -30.9 -23.6  070  12  6   8.0   4.4
 23000 -29.1 -20.4  040   8  4   8.1   4.4 | -28.6 -19.5  070   9  5   8.0   4.4
 22000 -26.7 -16.1  035   7  4   8.1   4.4 | -26.2 -15.2  070   7  3   8.0   4.4
 21000 -24.3 -11.7  025   6  3   8.0   4.4 | -23.8 -10.8  070   4  2   7.9   4.3
 20000 -21.9  -7.4  025   7  4   8.0   4.4 | -21.5  -6.7  060   4  2   7.9   4.3
 19500 -20.7  -5.3  020   8  4   8.0   4.4 | -20.3  -4.5  055   5  2   7.9   4.3
 19000 -19.5  -3.1  020   8  4   7.9   4.3 | -19.1  -2.4  050   5  2   7.8   4.3
 18500 -18.3  -0.9  020   8  4   7.1   3.9 | -18.0  -0.4  045   5  3   7.3   4.0
 18000 -17.5   0.5  015   8  4   5.5   3.0 | -17.0   1.4  040   5  3   6.6   3.6
 17500 -16.7   1.9  010   9  4   5.4   3.0 | -16.0   3.2  040   6  3   6.6   3.6
 17000 -15.7   3.7  010   8  4   6.9   3.8 | -15.1   4.8  035   6  3   6.0   3.3
 16500 -14.7   5.5  010   8  4   6.8   3.8 | -14.2   6.4  025   5  3   6.0   3.3
 16000 -13.7   7.3  010   7  4   6.9   3.8 | -13.2   8.2  015   5  3   6.9   3.8
 15500 -12.7   9.1  360   7  3   7.0   3.8 | -12.2  10.0  010   6  3   7.2   3.9
 15000 -11.6  11.1  350   7  4   7.0   3.8 | -10.6  12.9  005   6  3   7.5   4.1
 14500 -10.1  13.8  345   7  3   7.0   3.8 |  -9.5  14.9  355   6  3   7.5   4.1
 14000  -9.1  15.6  335   7  3   5.8   3.2 |  -8.4  16.9  350   6  3   7.0   3.9
 13500  -8.3  17.1  330   7  4   5.4   3.0 |  -7.4  18.7  345   7  4   6.9   3.8
 13000  -7.6  18.3  320   7  4   5.9   3.2 |  -6.4  20.5  340   7  4   6.1   3.4
 12500  -6.7  19.9  315   7  4   6.6   3.6 |  -5.6  21.9  335   7  4   5.9   3.3
 12000  -5.9  21.4  310   7  4   5.1   2.8 |  -4.9  23.2  335   8  4   4.3   2.4
 11750  -5.4  22.3  305   7  4   7.3   4.0 |  -4.5  23.9  330   7  4   5.6   3.1
 11500  -4.9  23.2  305   7  4   6.6   3.6 |  -4.1  24.6  330   7  4   5.2   2.8
 11250  -4.4  24.1  300   7  4   7.3   4.0 |  -3.7  25.3  325   7  4   5.7   3.1
 11000  -3.8  25.2  290   7  3   7.3   4.0 |  -3.3  26.1  325   7  4   6.4   3.5
 10750  -3.3  26.1  290   7  4   6.8   3.7 |  -2.8  27.0  325   7  4   6.5   3.5
 10500  -2.8  27.0  285   7  4   7.0   3.8 |  -2.3  27.9  325   7  3   6.6   3.6
 10250  -2.3  27.9  285   7  4   6.8   3.7 |  -1.8  28.8  325   7  3   6.1   3.4
 10000  -1.8  28.8  280   8  4   4.4   2.4 |  -1.4  29.5  325   7  3   5.1   2.8
  9750  -1.6  29.1  275   8  4   4.6   2.5 |  -1.0  30.2  325   7  3   6.0   3.3
  9500  -1.1  30.0  275   8  4   6.6   3.6 |  -0.5  31.1  325   6  3   7.3   4.0
  9250  -0.7  30.7  270   8  4   5.4   2.9 |   0.0  32.0  325   6  3   6.3   3.4
  9000  -0.4  31.3  270   8  4   2.3   1.3 |   0.4  32.7  325   6  3   4.4   2.4
  8750  -0.3  31.5  260   8  4   2.6   1.4 |   0.7  33.3  320   6  3   4.7   2.6
  8500   0.1  32.2  260   8  4   6.0   3.3 |   1.1  34.0  320   6  3   6.9   3.8
  8250   0.4  32.7  255   9  4   0.8   0.4 |   1.6  34.9  320   6  3   2.9   1.6
  8000   0.1  32.2  255   8  4  -6.6  -3.6 |   1.5  34.7  320   6  3  -2.1  -1.1
  7750  -0.3  31.5  250   8  4  -1.8  -1.0 |   1.4  34.5  315   6  3   1.8   1.0
  7500  -0.2  31.6  245   8  4  -0.3  -0.2 |   1.7  35.1  305   5  3   3.3   1.8
  7250  -0.8  30.6  240   7  4 -18.4 -10.1 |   1.7  35.1  300   4  2  -3.6  -2.0
  7000  -3.0  26.6  245   6  3 -37.5 -20.6 |   1.1  34.0  300   3  2  -9.0  -4.9
  6750     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           01/17/2017 at 1400 MST          |       01/17/2017 at 1700 MST
                                           |
K index... +4.1  LI... +3.7                | K index... -5.2  LI... +4.0
CAPE... 0.0  CIN... M                      | 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 -59.7 -75.5  245  19 10   2.4   1.3 | -59.6 -75.3  240  19 10   2.5   1.4
 45000 -56.0 -68.8  235   9  5   1.4   0.8 | -55.6 -68.1  200  11  5   1.0   0.6
 40000 -55.0 -67.0  110   6  3   0.6   0.3 | -56.1 -69.0  085  14  7  -0.3  -0.2
 38000 -54.7 -66.5  090  14  7   0.4   0.2 | -55.8 -68.4  080  23 12   1.4   0.8
 36000 -54.5 -66.1  080  25 13   0.4   0.2 | -54.9 -66.8  080  34 17   1.4   0.8
 34000 -53.9 -65.0  080  36 18   6.5   3.6 | -53.8 -64.8  080  44 22   6.5   3.6
 32000 -49.4 -56.9  075  37 19   6.7   3.7 | -49.8 -57.6  080  46 24   6.6   3.6
 30000 -45.0 -49.0  070  37 19   8.6   4.7 | -45.1 -49.2  080  46 24   8.2   4.5
 29000 -42.4 -44.3  070  36 18   8.7   4.8 | -42.6 -44.7  075  42 22   8.3   4.5
 28000 -39.8 -39.6  075  35 18   8.7   4.7 | -40.1 -40.2  075  38 20   8.3   4.5
 27000 -37.2 -35.0  075  34 17   8.2   4.5 | -37.7 -35.9  075  34 18   8.4   4.6
 26000 -34.9 -30.8  075  30 16   7.8   4.3 | -35.1 -31.2  075  33 17   8.4   4.6
 25000 -32.6 -26.7  075  27 14   7.8   4.3 | -32.6 -26.7  075  32 17   8.4   4.6
 24000 -30.2 -22.4  080  23 12   7.8   4.3 | -30.1 -22.2  075  31 16   8.3   4.6
 23000 -27.9 -18.2  075  18  9   7.7   4.2 | -27.7 -17.9  070  28 14   7.8   4.3
 22000 -25.6 -14.1  075  13  7   7.7   4.2 | -25.3 -13.5  070  24 12   7.8   4.3
 21000 -23.3  -9.9  065   8  4   7.8   4.3 | -23.0  -9.4  065  20 11   7.6   4.2
 20000 -21.0  -5.8  060   7  3   7.8   4.3 | -20.7  -5.3  065  16  8   7.5   4.1
 19500 -19.8  -3.6  055   6  3   7.8   4.3 | -19.6  -3.3  065  14  7   7.5   4.1
 19000 -18.6  -1.5  050   5  3   7.8   4.3 | -18.5  -1.3  060  12  6   7.5   4.1
 18500 -17.5   0.5  045   4  2   7.4   4.1 | -17.4   0.7  055  10  5   7.2   4.0
 18000 -16.4   2.5  040   4  2   6.9   3.8 | -16.3   2.7  055   9  5   6.8   3.7
 17500 -15.4   4.3  040   4  2   7.0   3.8 | -15.3   4.5  050   7  4   6.9   3.8
 17000 -14.5   5.9  040   4  2   6.0   3.3 | -14.4   6.1  045   6  3   6.0   3.3
 16500 -13.6   7.5  030   3  2   6.0   3.3 | -13.5   7.7  040   5  3   6.1   3.4
 16000 -12.6   9.3  015   3  1   6.4   3.5 | -12.6   9.3  035   4  2   6.3   3.5
 15500 -11.1  12.0  360   3  2   6.6   3.6 | -11.1  12.0  020   3  2   6.4   3.5
 15000 -10.1  13.8  355   3  2   7.5   4.1 | -10.1  13.8  015   3  1   7.1   3.9
 14500  -9.0  15.8  350   3  2   7.6   4.2 |  -9.1  15.6  010   2  1   7.2   3.9
 14000  -7.9  17.8  345   3  2   7.2   4.0 |  -8.0  17.6  005   2  1   7.4   4.1
 13500  -6.9  19.6  340   4  2   7.1   3.9 |  -6.9  19.6  355   2  1   7.4   4.1
 13000  -5.8  21.6  335   4  2   6.9   3.8 |  -5.8  21.6  340   2  1   7.0   3.9
 12500  -4.8  23.4  330   4  2   7.1   3.9 |  -4.8  23.4  330   2  1   6.7   3.7
 12000  -4.0  24.8  330   5  2   4.4   2.4 |  -3.8  25.2  315   3  1   6.2   3.4
 11750  -3.6  25.5  325   5  2   5.9   3.3 |  -3.4  25.9  315   3  1   6.0   3.3
 11500  -3.2  26.2  325   5  2   5.5   3.0 |  -2.9  26.8  310   3  2   5.8   3.2
 11250  -2.8  27.0  320   5  2   5.6   3.1 |  -2.5  27.5  310   3  2   6.8   3.7
 11000  -2.4  27.7  320   5  2   5.3   2.9 |  -1.9  28.6  305   3  2   6.9   3.8
 10750  -2.1  28.2  320   5  2   5.2   2.8 |  -1.5  29.3  305   4  2   5.8   3.2
 10500  -1.7  28.9  315   5  2   5.2   2.9 |  -1.0  30.2  300   4  2   6.2   3.4
 10250  -1.3  29.7  315   5  2   5.1   2.8 |  -0.6  30.9  300   4  2   6.0   3.3
 10000  -0.9  30.4  315   4  2   4.6   2.5 |  -0.2  31.6  300   4  2   5.5   3.0
  9750  -0.6  30.9  315   5  2   4.8   2.6 |   0.2  32.4  300   4  2   5.8   3.2
  9500  -0.2  31.6  315   5  2   5.3   2.9 |   0.6  33.1  300   5  2   6.4   3.5
  9250   0.1  32.2  315   5  2   5.0   2.8 |   1.1  34.0  295   5  3   6.2   3.4
  9000   0.5  32.9  315   5  2   4.4   2.4 |   1.5  34.7  295   5  3   5.7   3.1
  8750   0.8  33.4  315   4  2   4.8   2.6 |   1.9  35.4  290   5  3   6.1   3.4
  8500   1.2  34.2  315   4  2   6.0   3.3 |   2.3  36.1  285   5  2   7.7   4.2
  8250   1.6  34.9  315   4  2   4.4   2.4 |   2.8  37.0  275   5  2   4.7   2.6
  8000   1.8  35.2  310   4  2   1.9   1.0 |   2.9  37.2  270   4  2  -0.4  -0.2
  7750   1.9  35.4  305   4  2   4.6   2.5 |   2.9  37.2  260   4  2   3.1   1.7
  7500   2.4  36.3  300   3  1   6.5   3.6 |   3.3  37.9  250   4  2   6.3   3.5
  7250   2.6  36.7  295   2  1  -0.5  -0.3 |   3.3  37.9  240   4  2  -9.2  -5.1
  7000   2.1  35.8  280   2  1  -8.2  -4.5 |   1.7  35.1  240   4  2 -30.6 -16.8
  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.