Soaring Guidance
Issued by NWS Grand Junction, 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
000
UXUS97 KGJT 031304
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0704 MDT Tuesday, May 3, 2016

This forecast is for Tuesday, May 3, 2016:

If the trigger temperature of 61.9 F/16.6 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 861 ft/min (4.4 m/s)
   Maximum height of thermals.................. 15134 ft MSL (10295 ft AGL)

Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 1130 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................. 13455 ft MSL (8615 ft AGL)
Thermal soaring outlook for Wednesday 05/04.... Fair

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

Remarks...

Sunrise/Sunset.................... 06:12:59 / 20:08:43 MDT
Total possible sunshine........... 13 hr 55 min 44 sec (835 min 44 sec)
Altitude of sun at 13:11:02 MDT... 66.85 degrees

Upper air data from rawinsonde observation taken on 05/03/2016 at 0600 MDT

Freezing level.................. 10732 ft MSL (5893 ft AGL)
Convective condensation level... 13422 ft MSL (8583 ft AGL)
Lifted condensation level....... 14827 ft MSL (9988 ft AGL)
Lifted index.................... -1.4
K index......................... +1.4

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   285   36   18   1.0   0.5  103.5 218.3    46.2      M    M
 45000  -56.9 -70.4   285   38   20   1.4   0.8   81.2 178.1    36.0      M    M
 40000  -59.9 -75.8   300    9    4  -4.9  -2.7   53.4 128.1    20.4      M    M
 38000  -60.0 -76.0   035   20   10  -0.6  -0.3   44.5 112.2    15.0      M    M
 36000  -58.8 -73.8   065   29   15   6.5   3.5   37.6  99.6    10.6      M    M
 34000  -54.7 -66.5   075   35   18   8.8   4.8   35.2  95.3     9.2      M    M
 32000  -48.7 -55.7   085   30   15   8.9   4.9   34.4  93.9     8.9      M    M
 30000  -44.4 -47.9   055   29   15   5.9   3.2   32.2  90.0     7.5      M    M
 29000  -41.9 -43.4   045   28   14   8.5   4.7   31.6  89.0     7.1      M    M
 28000  -39.4 -38.9   040   27   14   8.5   4.7   31.3  88.3     6.9      M    M
 27000  -36.8 -34.2   045   25   13   8.5   4.7   30.7  87.2     6.6      M    M
 26000  -34.2 -29.6   045   24   12   8.9   4.9   30.2  86.4     6.3      M    M
 25000  -32.7 -26.9   050   22   11  10.0   5.5   28.5  83.4     5.0      M    M
 24000  -29.9 -21.8   055   18   10   9.1   5.0   28.3  83.0     4.9      M    M
 23000  -27.2 -17.0   065   16    8   9.2   5.0   28.1  82.6     4.8      M    M
 22000  -24.5 -12.1   050   19   10   9.2   5.0   28.0  82.4     4.7      M    M
 21000  -21.7  -7.1   050   19   10   9.2   5.0   27.7  81.9     4.6      M    M
 20000  -19.0  -2.2   050   18    9   9.2   5.0   27.6  81.7     4.5      M    M
 19500  -17.6   0.3   050   16    8   9.2   5.0   27.5  81.4     4.4      M    M
 19000  -16.2   2.8   050   13    7   9.1   5.0   27.4  81.2     4.3      M    M
 18500  -14.9   5.2   045   14    7   7.7   4.2   27.2  81.0     4.3      M    M
 18000  -14.1   6.6   030   14    7   5.1   2.8   26.5  79.7     3.6      M    M
 17500  -13.3   8.1   030   17    8   5.4   3.0   25.7  78.3     2.9      M    M
 17000  -11.9  10.6   040   21   11   6.6   3.6   24.8  76.7     2.1      M    M
 16500  -11.0  12.2   040   22   11   6.6   3.6   24.3  75.7     1.6      M    M
 16000  -10.0  14.0   040   22   11   6.5   3.6   23.8  74.8     1.2      M    M
 15500   -9.1  15.6   040   22   11   4.9   2.7   23.2  73.8     0.7      M    M
 15000   -8.9  16.0   040   22   11   2.9   1.6   21.8  71.3    -0.6    853  4.3
 14500   -7.7  18.1   040   22   11   4.8   2.6   21.3  70.3    -0.9    804  4.1
 14000   -7.3  18.9   040   22   11   3.3   1.8   20.2  68.3    -2.0    777  3.9
 13500   -6.9  19.6   035   19   10   6.0   3.3   19.1  66.4    -3.0    749  3.8
 13000   -5.6  21.9   035   17    9   8.3   4.6   18.9  66.0    -3.3    697  3.5
 12500   -4.4  24.1   025   14    7   8.5   4.7   18.7  65.6    -3.5    645  3.3
 12000   -3.1  26.4   020   12    6   8.5   4.7   18.5  65.3    -3.7    593  3.0
 11500   -1.9  28.6   020   12    6   8.5   4.7   18.3  64.9    -4.0    541  2.7
 11000   -0.6  30.9   015   11    6   8.6   4.7   18.1  64.5    -4.2    489  2.5
 10500    0.6  33.1   015   11    6   8.6   4.7   17.9  64.2    -4.4    437  2.2
 10250    1.2  34.2   015   11    6   8.3   4.6   17.8  64.0    -4.6    410  2.1
 10000    1.8  35.2   015   11    5   8.0   4.4   17.6  63.8    -4.7    385  2.0
  9750    2.4  36.3   015   10    5   8.1   4.4   17.5  63.5    -4.8    359  1.8
  9500    3.0  37.4   020   10    5   8.2   4.5   17.4  63.3    -5.0    334  1.7
  9250    3.6  38.5   020    9    5   8.6   4.7   17.3  63.1    -5.1    309  1.6
  9000    4.2  39.6   020    9    5   9.1   5.0   17.2  63.0    -5.3    283  1.4
  8750    4.8  40.6   020    9    5   8.3   4.6   17.2  62.9    -5.4    258  1.3
  8500    5.4  41.7   020    9    4   7.9   4.3   17.0  62.6    -5.6    233  1.2
  8250    6.0  42.8   020    8    4   7.0   3.8   16.8  62.3    -5.7    208  1.1
  8000    6.4  43.5   020    8    4   4.6   2.5   16.5  61.8    -6.0    188  1.0
  7750    6.7  44.1   015    7    4   4.2   2.3   16.1  61.0    -6.5    173  0.9
  7500    7.0  44.6   360    6    3   5.1   2.8   15.7  60.3    -7.0    157  0.8
  7250    7.4  45.3   345    5    3   5.6   3.1   15.4  59.7    -7.4    138  0.7
  7000    7.8  46.0   330    5    3   5.5   3.0   15.1  59.1    -7.7    119  0.6
  6750    8.1  46.6   325    4    2   5.5   3.0   14.7  58.5    -8.1    100  0.5
  6500    8.5  47.3   325    4    2   5.5   3.0   14.4  57.9    -8.4     80  0.4
  6250    8.9  48.0   325    3    2   5.3   2.9   14.1  57.3    -8.8     61  0.3
  6000    9.3  48.7   320    2    1   6.3   3.4   13.8  56.8    -9.1     42  0.2
  5750    9.7  49.5   305    2    1   2.6   1.4   13.4  56.2    -9.5     23  0.1
  5500    9.7  49.5   275    1    1  -2.9  -1.6   12.6  54.7   -10.3     16  0.1
  5250    9.4  48.9   230    1    1  -4.8  -2.7   11.6  52.9   -11.3     17  0.1
  5000    8.7  47.7   210    2    1 -13.9  -7.6   10.3  50.5   -12.7     30  0.2

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

           05/03/2016 at 0900 MDT          |       05/03/2016 at 1200 MDT
                                           |
K index... +11.4  LI... +277.4             | K index... +1.2  LI... +276.4
CAPE... 0.0  CIN... -0.4                   | CAPE... 0.0  CIN... -1.2
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -58.7 -73.7  295  32 17   1.4   0.8 | -59.3 -74.7  300  29 15   1.7   0.9
 45000 -56.8 -70.2  295  29 15  -3.0  -1.6 | -57.1 -70.8  305  27 14  -2.8  -1.6
 40000 -60.8 -77.4  025  15  8  -2.7  -1.5 | -60.6 -77.1  015  10  5  -2.4  -1.3
 38000 -59.7 -75.5  055  21 11   4.8   2.7 | -59.4 -74.9  055  12  6   4.7   2.6
 36000 -56.8 -70.2  065  26 14   4.8   2.7 | -56.5 -69.7  070  17  9   4.7   2.6
 34000 -53.6 -64.5  070  31 16   7.1   3.9 | -52.6 -62.7  075  21 11   7.5   4.1
 32000 -48.7 -55.7  060  31 16   7.2   3.9 | -48.2 -54.8  060  23 12   7.4   4.1
 30000 -44.1 -47.4  055  31 16   8.3   4.6 | -43.6 -46.5  050  24 12   7.9   4.3
 29000 -41.7 -43.1  055  30 15   8.3   4.6 | -41.3 -42.3  050  24 13   7.9   4.3
 28000 -39.2 -38.6  050  29 15   8.3   4.6 | -38.9 -38.0  045  24 13   7.9   4.3
 27000 -36.6 -33.9  050  28 14   8.7   4.8 | -36.5 -33.7  045  24 13   8.5   4.7
 26000 -34.0 -29.2  050  27 14   8.7   4.8 | -33.9 -29.0  045  24 12   8.5   4.7
 25000 -31.4 -24.5  045  26 14   8.7   4.8 | -31.4 -24.5  045  23 12   8.5   4.7
 24000 -28.9 -20.0  045  25 13   8.4   4.6 | -28.8 -19.8  045  23 12   8.5   4.7
 23000 -26.4 -15.5  045  24 12   8.4   4.6 | -26.3 -15.3  045  22 11   8.5   4.7
 22000 -23.9 -11.0  045  23 12   8.4   4.6 | -23.7 -10.7  045  21 11   8.5   4.7
 21000 -21.4  -6.5  045  22 11   7.9   4.3 | -21.2  -6.2  045  20 10   8.0   4.4
 20000 -19.0  -2.2  045  21 11   7.9   4.3 | -18.3  -0.9  050  19 10   8.0   4.4
 19500 -17.9  -0.2  045  20 10   7.9   4.3 | -17.1   1.2  050  18  9   8.0   4.4
 19000 -16.1   3.0  045  19 10   7.8   4.3 | -15.9   3.4  050  18  9   8.1   4.4
 18500 -14.9   5.2  045  19 10   7.7   4.2 | -14.7   5.5  050  18  9   8.1   4.5
 18000 -13.8   7.2  045  19 10   7.8   4.3 | -13.4   7.9  050  18  9   8.1   4.5
 17500 -12.7   9.1  045  19 10   6.3   3.5 | -12.3   9.9  050  18  9   7.7   4.2
 17000 -11.8  10.8  045  18  9   6.5   3.6 | -11.1  12.0  050  18 10   7.7   4.2
 16500 -10.9  12.4  045  18  9   6.2   3.4 | -10.0  14.0  050  19 10   7.6   4.2
 16000 -10.0  14.0  040  18  9   6.2   3.4 |  -8.8  16.2  050  18  9   7.6   4.2
 15500  -9.1  15.6  040  17  9   6.5   3.5 |  -7.7  18.1  050  18  9   7.4   4.1
 15000  -8.1  17.4  035  17  8   6.9   3.8 |  -6.6  20.1  050  18  9   7.2   4.0
 14500  -7.1  19.2  035  16  8   6.8   3.8 |  -5.5  22.1  050  18  9   6.9   3.8
 14000  -6.2  20.8  035  16  8   5.3   2.9 |  -4.7  23.5  050  18  9   5.0   2.7
 13500  -5.4  22.3  035  18  9   5.4   3.0 |  -3.9  25.0  050  18  9   5.1   2.8
 13000  -4.6  23.7  035  18  9   5.0   2.8 |  -3.2  26.2  050  19 10   5.6   3.1
 12500  -3.9  25.0  035  19 10   4.8   2.6 |  -2.4  27.7  045  20 10   5.7   3.1
 12000  -3.0  26.6  035  19 10   8.1   4.5 |  -1.6  29.1  045  21 11   6.1   3.3
 11500  -1.8  28.8  030  18  9   7.9   4.3 |  -0.7  30.7  040  21 11   6.0   3.3
 11000  -0.6  30.9  025  18  9   9.3   5.1 |   0.3  32.5  040  20 10   7.7   4.2
 10500   0.8  33.4  025  16  8  10.4   5.7 |   1.4  34.5  035  18  9   7.7   4.2
 10250   1.4  34.5  025  15  8   4.3   2.4 |   1.9  35.4  035  17  9   4.3   2.3
 10000   1.6  34.9  025  15  8   5.8   3.2 |   2.2  36.0  035  16  8   6.6   3.6
  9750   2.4  36.3  025  14  7  13.0   7.1 |   2.9  37.2  035  15  8  11.2   6.1
  9500   3.3  37.9  025  13  7  11.1   6.1 |   3.7  38.7  035  14  7   9.6   5.3
  9250   4.1  39.4  025  13  6   7.9   4.3 |   4.3  39.7  035  12  6   6.9   3.8
  9000   4.5  40.1  025  12  6   6.0   3.3 |   4.8  40.6  035  12  6   6.7   3.6
  8750   5.1  41.2  025  11  6   8.5   4.7 |   5.4  41.7  035  11  6   9.2   5.0
  8500   5.7  42.3  025  10  5   7.4   4.0 |   6.1  43.0  035  10  5   8.6   4.7
  8250   6.2  43.2  025   9  5   4.4   2.4 |   6.6  43.9  035   9  4   7.5   4.1
  8000   6.4  43.5  030   9  4   3.4   1.9 |   7.2  45.0  030   8  4   7.6   4.1
  7750   6.7  44.1  030   8  4   3.8   2.1 |   7.7  45.9  030   7  3   8.5   4.7
  7500   7.0  44.6  035   7  3   2.9   1.6 |   8.4  47.1  030   6  3   8.8   4.9
  7250   7.1  44.8  040   6  3   2.1   1.2 |   9.0  48.2  025   5  3   8.7   4.8
  7000   7.3  45.1  045   5  2   2.2   1.2 |   9.6  49.3  025   5  3   8.7   4.8
  6750   7.4  45.3  055   4  2   2.4   1.3 |  10.3  50.5  025   5  2   9.8   5.4
  6500   7.6  45.7  060   3  2   3.4   1.9 |  11.0  51.8  025   4  2  10.6   5.8
  6250   7.8  46.0  075   2  1   3.9   2.2 |  11.8  53.2  025   4  2  10.3   5.6
  6000   8.1  46.6  100   2  1   4.0   2.2 |  12.6  54.7  020   3  2  10.5   5.8
  5750   8.5  47.3  120   2  1  11.7   6.4 |  13.5  56.3  020   3  2  17.1   9.4
  5500   9.8  49.6  125   2  1  23.7  13.0 |  15.2  59.4  020   3  2  27.4  15.0
  5250     M     M    M   M  M     M     M |     M     M    M   M  M     M     M
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           05/03/2016 at 1500 MDT          |       05/03/2016 at 1800 MDT
                                           |
K index... +7.8  LI... +275.0              | K index... +11.1  LI... +274.1
CAPE... 0.0  CIN... -3.7                   | CAPE... +7.8  CIN... -67.2
                                           |
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  295  27 14   1.2   0.7 | -60.1 -76.2  295  25 13   0.6   0.3
 45000 -58.1 -72.6  310  24 12  -2.4  -1.3 | -59.4 -74.9  305  22 11  -1.6  -0.9
 40000 -61.2 -78.2  360   8  4  -2.0  -1.1 | -61.5 -78.7  035   7  4  -1.4  -0.8
 38000 -59.4 -74.9  035   7  4   5.6   3.0 | -59.0 -74.2  050   7  4   5.9   3.2
 36000 -56.1 -69.0  055   7  4   5.5   3.0 | -55.5 -67.9  055   7  3   5.9   3.2
 34000 -51.7 -61.1  065   9  4   7.9   4.3 | -51.3 -60.3  055   6  3   8.4   4.6
 32000 -46.9 -52.4  060  12  6   7.9   4.3 | -46.3 -51.3  055   6  3   8.4   4.6
 30000 -42.4 -44.3  055  14  7   7.0   3.9 | -41.6 -42.9  045   6  3   7.0   3.8
 29000 -40.3 -40.5  050  15  8   7.0   3.9 | -39.5 -39.1  035   7  4   7.0   3.8
 28000 -38.2 -36.8  050  16  8   7.1   3.9 | -37.4 -35.3  030   8  4   7.0   3.8
 27000 -35.9 -32.6  045  17  9   8.4   4.6 | -35.3 -31.5  030   9  5   7.8   4.3
 26000 -33.3 -27.9  045  17  9   8.5   4.6 | -32.4 -26.3  035  10  5   7.8   4.3
 25000 -30.8 -23.4  050  17  9   8.5   4.6 | -30.1 -22.2  035  11  6   7.8   4.3
 24000 -28.3 -18.9  050  17  9   8.5   4.7 | -27.6 -17.7  040  11  6   8.5   4.7
 23000 -25.7 -14.3  050  17  9   8.5   4.7 | -25.1 -13.2  045  11  6   8.6   4.7
 22000 -23.2  -9.8  050  17  9   8.5   4.7 | -22.5  -8.5  050  11  6   8.6   4.7
 21000 -20.6  -5.1  050  17  9   8.6   4.7 | -20.0  -4.0  050  11  6   8.5   4.7
 20000 -18.0  -0.4  055  16  8   8.6   4.7 | -17.4   0.7  055  11  5   8.5   4.7
 19500 -16.7   1.9  055  16  8   8.6   4.7 | -16.2   2.8  055  10  5   8.5   4.7
 19000 -15.5   4.1  055  16  8   8.4   4.6 | -14.9   5.2  055  10  5   8.2   4.5
 18500 -14.3   6.3  055  16  8   7.8   4.3 | -13.7   7.3  060  11  5   7.8   4.3
 18000 -13.1   8.4  055  15  8   7.9   4.3 | -12.6   9.3  065  11  6   7.8   4.3
 17500 -11.9  10.6  060  15  8   7.7   4.2 | -11.4  11.5  065  11  6   8.0   4.4
 17000 -10.8  12.6  060  15  8   7.7   4.2 | -10.2  13.6  070  11  6   8.0   4.4
 16500  -9.6  14.7  060  16  8   7.9   4.3 |  -9.0  15.8  070  11  6   8.1   4.4
 16000  -7.8  18.0  060  16  8   8.1   4.4 |  -7.8  18.0  075  11  6   8.1   4.5
 15500  -6.6  20.1  065  17  9   7.6   4.2 |  -6.6  20.1  080  11  6   8.2   4.5
 15000  -5.5  22.1  065  17  9   7.4   4.1 |  -5.4  22.3  080  12  6   8.2   4.5
 14500  -4.4  24.1  065  18  9   7.4   4.1 |  -4.2  24.4  080  12  6   8.3   4.5
 14000  -3.3  26.1  065  17  9   7.5   4.1 |  -3.0  26.6  080  12  6   7.9   4.3
 13500  -2.2  28.0  065  17  9   7.2   3.9 |  -1.8  28.8  080  12  6   8.1   4.4
 13000  -1.2  29.8  060  17  9   6.1   3.4 |  -0.3  31.5  065  12  6   6.8   3.7
 12500  -0.3  31.5  050  16  8   6.1   3.4 |   0.7  33.3  060  11  6   6.9   3.8
 12000   0.6  33.1  045  15  8   5.8   3.2 |   1.8  35.2  050  12  6   7.3   4.0
 11500   1.4  34.5  040  15  7   6.1   3.4 |   2.8  37.0  045  12  6   7.5   4.1
 11000   2.3  36.1  035  13  7   7.4   4.0 |   3.9  39.0  040  12  6   8.1   4.4
 10500   3.4  38.1  035  12  6   4.9   2.7 |   5.1  41.2  040  12  6   4.3   2.3
 10250   3.6  38.5  030  12  6   5.0   2.7 |   5.3  41.5  040  12  6   5.2   2.9
 10000   4.2  39.6  030  11  6  10.2   5.6 |   6.0  42.8  040  11  6  11.1   6.1
  9750   5.0  41.0  030  10  5  11.4   6.2 |   6.7  44.1  035  10  5   9.9   5.4
  9500   5.8  42.4  030  10  5   9.4   5.2 |   7.4  45.3  035  10  5   9.2   5.0
  9250   6.4  43.5  030   9  5   6.6   3.6 |   8.0  46.4  035   9  5   7.7   4.2
  9000   6.9  44.4  030   8  4   8.7   4.8 |   8.6  47.5  035   9  4   8.6   4.7
  8750   7.7  45.9  025   8  4  10.8   5.9 |   9.3  48.7  035   8  4   9.3   5.1
  8500   8.4  47.1  025   7  4   9.7   5.3 |   9.9  49.8  035   7  3   8.5   4.6
  8250   9.1  48.4  025   7  4   9.0   4.9 |  10.5  50.9  035   6  3   7.6   4.2
  8000   9.8  49.6  025   7  3   9.8   5.4 |  11.1  52.0  035   5  3   8.4   4.6
  7750  10.6  51.1  030   6  3  10.7   5.9 |  11.7  53.1  035   5  2   9.1   5.0
  7500  11.4  52.5  030   6  3  10.3   5.6 |  12.4  54.3  035   4  2   9.4   5.2
  7250  12.1  53.8  030   6  3  10.2   5.6 |  13.1  55.6  035   4  2   9.6   5.3
  7000  12.9  55.2  030   6  3   9.9   5.4 |  13.8  56.8  035   4  2   9.9   5.5
  6750  13.6  56.5  025   5  3  10.1   5.6 |  14.6  58.3  035   3  2  10.5   5.8
  6500  14.4  57.9  025   5  3  10.9   6.0 |  15.4  59.7  035   3  2  10.4   5.7
  6250  15.2  59.4  025   5  2  11.1   6.1 |  16.2  61.2  035   3  2  10.6   5.8
  6000  16.0  60.8  025   4  2  10.3   5.7 |  16.9  62.4  035   3  1   9.7   5.3
  5750  16.8  62.2  025   4  2  12.2   6.7 |  17.6  63.7  035   2  1   9.2   5.1
  5500  17.9  64.2  025   4  2  15.0   8.2 |  18.3  64.9  035   2  1  10.0   5.5
  5250  18.9  66.0  025   4  2  12.8   7.0 |  19.0  66.2  030   2  1   9.4   5.1
  5000     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 at Walker Field in Grand
Junction, Colorado at

                   North Latitude:  39 deg 07 min 00.001 sec
                   West Longitude: 108 deg 31 min 59.998 sec
                   Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado.  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.