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 14
000
UXUS97 KGJT 291234
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0634 MDT Wednesday, March 29, 2017

This forecast is for Wednesday, March 29, 2017:

If the trigger temperature of 51.0 F/10.6 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 849 ft/min (4.3 m/s)
   Maximum height of thermals.................. 15424 ft MSL (10585 ft AGL)

Forecast maximum temperature................... 64.0 F/18.2 C
Time of trigger temperature.................... 1115 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 12116 ft MSL (7277 ft AGL)
Thermal soaring outlook for Thursday 03/30..... Good

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

Remarks...

Sunrise/Sunset.................... 07:02:50 / 19:34:18 MDT
Total possible sunshine........... 12 hr 31 min 28 sec (751 min 28 sec)
Altitude of sun at 13:18:43 MDT... 54.57 degrees

Upper air data from rawinsonde observation taken on 03/29/2017 at 0600 MDT

Freezing level.................. 8201 ft MSL (3362 ft AGL)
Convective condensation level... 13866 ft MSL (9027 ft AGL)
Lifted condensation level....... 14448 ft MSL (9609 ft AGL)
Lifted index.................... +0.7
K index......................... +4.3

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  -58.6 -73.5   285   19   10  -2.2  -1.2  105.4 221.7    49.7      M    M
 45000  -54.7 -66.5   320   19   10   0.2   0.1   87.0 188.5    42.0      M    M
 40000  -53.7 -64.7   355   16    8   2.8   1.5   65.0 149.0    30.6      M    M
 38000  -60.1 -76.2   330   38   19 -23.9 -13.1   45.4 113.6    18.5      M    M
 36000  -58.4 -73.1   355   33   17   6.8   3.7   39.1 102.4    14.7      M    M
 34000  -54.2 -65.6   005   48   25   8.6   4.7   36.9  98.4    13.5      M    M
 32000  -50.0 -58.0   010   69   35   8.9   4.9   34.5  94.2    12.2      M    M
 30000  -45.6 -50.1   010   71   37   6.0   3.3   32.5  90.5    11.0      M    M
 29000  -43.8 -46.8   010   68   35   6.0   3.3   30.9  87.6     9.9      M    M
 28000  -42.0 -43.6   010   65   33   6.1   3.3   29.5  85.0     8.9      M    M
 27000  -40.6 -41.1   005   61   32   4.0   2.2   27.6  81.6     7.6      M    M
 26000  -38.6 -37.5   005   58   30   8.9   4.9   26.3  79.4     6.7      M    M
 25000  -35.8 -32.4   005   55   28   9.3   5.1   26.2  79.2     6.7      M    M
 24000  -33.0 -27.4   005   53   28   9.2   5.0   26.0  78.8     6.6      M    M
 23000  -30.8 -23.4   005   50   26   6.9   3.8   25.0  77.0     5.9      M    M
 22000  -28.7 -19.7   010   47   24   6.9   3.8   23.9  75.1     5.1      M    M
 21000  -26.7 -16.1   010   44   22   6.7   3.7   23.0  73.3     4.3      M    M
 20000  -23.8 -10.8   015   40   21   7.9   4.4   22.1  71.8     3.7      M    M
 19500  -22.6  -8.7   015   42   21   7.9   4.4   21.8  71.2     3.4      M    M
 19000  -21.4  -6.5   015   43   22   7.9   4.3   21.4  70.6     3.1      M    M
 18500  -20.2  -4.4   015   44   23   8.4   4.6   21.1  70.1     2.9      M    M
 18000  -18.9  -2.0   015   45   23   8.5   4.7   20.9  69.6     2.7      M    M
 17500  -17.6   0.3   015   46   24   8.5   4.7   20.7  69.2     2.5      M    M
 17000  -16.3   2.7   010   47   24   8.8   4.8   20.5  68.8     2.4      M    M
 16500  -15.3   4.5   010   48   25   4.5   2.5   20.0  68.0     2.0      M    M
 16000  -14.6   5.7   010   48   25   3.7   2.0   19.1  66.4     1.2      M    M
 15500  -14.3   6.3   015   44   23   1.7   0.9   17.9  64.2     0.1      M    M
 15000  -13.6   7.5   015   40   20   9.1   5.0   17.1  62.7    -0.7    815  4.1
 14500  -12.2  10.0   020   36   18   9.2   5.0   17.0  62.6    -0.8    759  3.9
 14000  -10.9  12.4   025   32   16   9.2   5.1   16.9  62.4    -0.9    703  3.6
 13500   -9.5  14.9   025   31   16   9.6   5.2   16.8  62.2    -1.0    648  3.3
 13000   -8.3  17.1   030   29   15   4.6   2.5   16.5  61.6    -1.4    599  3.0
 12500   -7.8  18.0   030   28   14   4.0   2.2   15.5  59.9    -2.3    567  2.9
 12000   -7.2  19.0   035   27   14   5.1   2.8   14.6  58.2    -3.2    536  2.7
 11500   -7.4  18.7   040   28   15  -6.7  -3.7   12.9  55.1    -4.9    527  2.7
 11000   -7.0  19.4   040   29   15  10.4   5.7   11.8  53.2    -6.0    499  2.5
 10500   -5.6  21.9   045   31   16   9.1   5.0   11.7  53.0    -6.1    444  2.3
 10250   -5.0  23.0   045   32   16   9.0   5.0   11.6  52.9    -6.2    416  2.1
 10000   -4.3  24.3   045   32   17   9.1   5.0   11.6  52.8    -6.3    388  2.0
  9750   -3.6  25.5   045   32   17   9.1   5.0   11.5  52.7    -6.3    361  1.8
  9500   -2.9  26.8   040   32   17   8.9   4.9   11.5  52.7    -6.4    333  1.7
  9250   -2.3  27.9   040   33   17   7.7   4.2   11.4  52.5    -6.5    307  1.6
  9000   -1.8  28.8   040   33   17   7.1   3.9   11.2  52.1    -6.7    283  1.4
  8750   -1.3  29.7   040   33   17   7.2   4.0   11.0  51.8    -7.0    260  1.3
  8500   -0.7  30.7   040   34   17   7.2   3.9   10.8  51.4    -7.2    237  1.2
  8250   -0.2  31.6   035   34   18   7.2   4.0   10.6  51.0    -7.4    213  1.1
  8000    0.3  32.5   035   35   18   7.2   4.0   10.4  50.7    -7.6    190  1.0
  7750    0.9  33.6   030   31   16   7.2   4.0   10.2  50.3    -7.8    167  0.8
  7500    1.4  34.5   020   26   13   7.3   4.0   10.0  50.0    -8.1    144  0.7
  7250    2.0  35.6   010   21   11   8.8   4.8    9.8  49.7    -8.2    119  0.6
  7000    2.7  36.9   355   18   10   9.9   5.4    9.8  49.7    -8.3     90  0.5
  6750    3.4  38.1   350   17    9   9.6   5.3    9.8  49.7    -8.3     61  0.3
  6500    4.1  39.4   350   15    8   9.7   5.3    9.8  49.7    -8.3     31  0.2
  6250    4.9  40.8   345   13    7   9.7   5.3    9.8  49.7    -8.3      2  0.0
  6000    5.6  42.1   345   12    6   9.6   5.3    9.8  49.7    -8.4      M    M
  5750    6.3  43.3   340   10    5   9.8   5.4    9.8  49.7    -8.4      M    M
  5500    7.1  44.8   335    9    5   9.1   5.0    9.8  49.6    -8.4      M    M
  5250    7.8  46.0   330    8    4  11.7   6.4    9.8  49.6    -8.5      M    M
  5000    8.5  47.3   320    6    3   1.9   1.0    9.8  49.6    -8.5      M    M

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

           03/29/2017 at 0900 MDT          |       03/29/2017 at 1200 MDT
                                           |
K index... -10.9  LI... +4.1               | K index... -9.0  LI... +4.1
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
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 -58.2 -72.8  300   8  4   1.3   0.7 | -58.9 -74.0  300   9  4   0.7   0.4
 45000 -56.2 -69.2  335  19 10   1.6   0.9 | -57.9 -72.2  350  23 12   0.9   0.5
 40000 -57.8 -72.0  355  40 21  -1.1  -0.6 | -59.8 -75.6  360  41 21  -1.3  -0.7
 38000 -57.9 -72.2  360  50 26   1.1   0.6 | -59.6 -75.3  010  52 27   2.3   1.2
 36000 -57.3 -71.1  010  63 33   1.1   0.6 | -58.2 -72.8  020  69 36   2.3   1.2
 34000 -56.3 -69.3  015  77 39   7.3   4.0 | -56.3 -69.3  025  84 43   9.6   5.3
 32000 -51.5 -60.7  020  77 40   7.9   4.3 | -51.0 -59.8  020  80 41   8.9   4.9
 30000 -46.8 -52.2  020  77 40   8.0   4.4 | -45.7 -50.3  020  75 39   8.0   4.4
 29000 -44.4 -47.9  015  72 37   7.9   4.4 | -43.3 -45.9  020  72 37   8.1   4.4
 28000 -42.1 -43.8  015  68 35   7.9   4.4 | -40.3 -40.5  020  67 34   8.1   4.4
 27000 -39.1 -38.4  015  62 32   7.3   4.0 | -37.9 -36.2  020  63 33   8.3   4.6
 26000 -37.0 -34.6  010  58 30   6.8   3.7 | -35.4 -31.7  020  61 32   8.4   4.6
 25000 -35.0 -31.0  010  54 28   6.8   3.8 | -32.8 -27.0  015  60 31   8.4   4.6
 24000 -33.0 -27.4  010  50 26   7.2   3.9 | -30.3 -22.5  010  58 30   8.1   4.5
 23000 -30.6 -23.1  010  46 24   7.9   4.3 | -28.0 -18.4  010  56 29   7.9   4.3
 22000 -28.3 -18.9  010  43 22   7.9   4.3 | -25.6 -14.1  010  53 28   7.9   4.3
 21000 -25.9 -14.6  015  40 21   7.4   4.1 | -23.3  -9.9  010  50 26   6.4   3.5
 20000 -23.7 -10.7  015  38 20   7.3   4.0 | -21.5  -6.7  010  44 23   6.3   3.5
 19500 -22.6  -8.7  020  37 19   7.3   4.0 | -20.5  -4.9  010  41 21   6.3   3.5
 19000 -21.5  -6.7  020  36 19   7.3   4.0 | -19.6  -3.3  010  38 20   6.3   3.5
 18500 -20.4  -4.7  020  35 18   7.7   4.3 | -18.7  -1.7  015  35 18   6.7   3.7
 18000 -19.3  -2.7  020  35 18   8.0   4.4 | -17.6   0.3  015  33 17   6.8   3.7
 17500 -18.1  -0.6  020  34 18   8.1   4.5 | -16.6   2.1  015  31 16   6.9   3.8
 17000 -16.8   1.8  020  34 18   8.9   4.9 | -15.5   4.1  015  30 15   7.7   4.2
 16500 -15.4   4.3  020  34 18   8.9   4.9 | -14.3   6.3  015  28 15   7.7   4.2
 16000 -14.1   6.6  020  34 18   8.6   4.7 | -13.2   8.2  015  28 14   7.4   4.1
 15500 -12.8   9.0  020  34 17   8.6   4.7 | -12.1  10.2  020  27 14   7.4   4.1
 15000 -11.6  11.1  020  33 17   8.3   4.5 | -11.0  12.2  020  27 14   7.8   4.3
 14500 -10.3  13.5  020  32 16   8.1   4.4 |  -9.8  14.4  020  27 14   8.1   4.4
 14000  -9.1  15.6  020  30 16   7.2   3.9 |  -8.6  16.5  020  27 14   7.9   4.3
 13500  -8.3  17.1  020  28 15   5.6   3.1 |  -6.8  19.8  020  26 13   7.8   4.3
 13000  -7.1  19.2  020  26 13   4.1   2.2 |  -5.7  21.7  020  26 13   6.0   3.3
 12500  -6.6  20.1  020  24 12   3.9   2.1 |  -4.9  23.2  025  25 13   6.0   3.3
 12000  -6.1  21.0  025  22 11   3.1   1.7 |  -4.2  24.4  025  25 13   2.6   1.4
 11500  -5.7  21.7  030  22 11   3.0   1.6 |  -3.9  25.0  025  24 12   2.1   1.2
 11000  -5.3  22.5  035  21 11   3.6   2.0 |  -3.7  25.3  025  22 11   2.0   1.1
 10500  -4.8  23.4  035  18  9   4.1   2.2 |  -3.5  25.7  025  19 10   2.2   1.2
 10250  -4.6  23.7  035  17  9   2.3   1.3 |  -3.4  25.9  025  18  9   1.6   0.9
 10000  -4.4  24.1  040  16  8   5.0   2.8 |  -3.2  26.2  030  17  9   3.4   1.8
  9750  -3.8  25.2  040  16  8   8.6   4.7 |  -2.9  26.8  030  16  8   5.3   2.9
  9500  -3.2  26.2  045  15  8   8.0   4.4 |  -2.6  27.3  030  15  8   5.0   2.7
  9250  -2.7  27.1  045  15  8   6.7   3.7 |  -2.2  28.0  035  14  7   4.5   2.5
  9000  -2.2  28.0  050  16  8   6.2   3.4 |  -1.9  28.6  030  13  7   5.9   3.3
  8750  -1.7  28.9  050  17  9   8.1   4.4 |  -1.4  29.5  030  13  7   7.9   4.3
  8500  -1.1  30.0  050  18  9   7.7   4.2 |  -0.9  30.4  030  12  6   8.0   4.4
  8250  -0.6  30.9  050  19 10   6.5   3.6 |  -0.3  31.5  030  12  6   9.2   5.1
  8000  -0.2  31.6  045  20 10   5.6   3.1 |   0.4  32.7  030  11  6   9.8   5.4
  7750   0.2  32.4  040  22 11   4.2   2.3 |   1.1  34.0  025  11  6   9.3   5.1
  7500   0.4  32.7  040  22 12   4.9   2.7 |   1.8  35.2  030  11  6   9.8   5.4
  7250   0.8  33.4  040  21 11   6.3   3.4 |   2.6  36.7  030  11  6  10.5   5.8
  7000   1.3  34.3  040  19 10   6.4   3.5 |   3.3  37.9  030  11  5  10.2   5.6
  6750   1.7  35.1  040  18  9   5.7   3.1 |   4.1  39.4  025  10  5  10.0   5.5
  6500   2.0  35.6  040  15  8   3.0   1.7 |   4.9  40.8  025  10  5  11.0   6.0
  6250   2.2  36.0  040  13  6   2.2   1.2 |   5.7  42.3  025  10  5  12.2   6.7
  6000   2.4  36.3  045  10  5   1.7   0.9 |   6.6  43.9  025   9  5  10.0   5.5
  5750   2.5  36.5  045   6  3   3.3   1.8 |   7.3  45.1  025   9  5  12.0   6.6
  5500   2.8  37.0  045   5  3   5.7   3.2 |   8.4  47.1  025   9  5  16.3   9.0
  5250   3.2  37.8  045   5  3   3.8   2.1 |   9.5  49.1  025   9  5  12.9   7.1
  5000     M     M    M   M  M     M     M |     M     M    M   M  M     M     M

           03/29/2017 at 1500 MDT          |       03/29/2017 at 1800 MDT
                                           |
K index... +0.6  LI... +4.9                | K index... +4.1  LI... +4.7
CAPE... 0.0  CIN... 0.0                    | CAPE... 0.0  CIN... 0.0
                                           |
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 -59.4 -74.9  275  11  6   1.5   0.8 | -59.2 -74.6  300  13  7   0.3   0.1
 45000 -57.2 -71.0  350  10  5   1.9   1.0 | -58.8 -73.8  340  16  8   0.5   0.3
 40000 -62.5 -80.5  360  42 22  -3.6  -2.0 | -64.8 -84.6  340  49 25  -4.0  -2.2
 38000 -61.9 -79.4  005  51 26   5.4   2.9 | -63.2 -81.8  345  51 26   7.6   4.1
 36000 -58.6 -73.5  015  59 30   5.4   3.0 | -58.7 -73.7  360  47 24   7.6   4.1
 34000 -55.0 -67.0  025  66 34   8.7   4.8 | -54.0 -65.2  015  48 25   8.8   4.8
 32000 -49.8 -57.6  020  65 33   8.7   4.8 | -48.7 -55.7  015  50 26   8.8   4.8
 30000 -44.6 -48.3  015  64 33   8.3   4.6 | -43.5 -46.3  015  52 27   8.2   4.5
 29000 -42.1 -43.8  015  65 33   8.4   4.6 | -41.1 -42.0  010  52 27   8.2   4.5
 28000 -39.6 -39.3  015  65 34   8.4   4.6 | -38.6 -37.5  010  52 27   8.2   4.5
 27000 -36.5 -33.7  015  65 33   8.6   4.7 | -36.2 -33.2  005  53 27   8.2   4.5
 26000 -33.9 -29.0  015  62 32   8.6   4.7 | -33.1 -27.6  005  50 26   8.2   4.5
 25000 -31.4 -24.5  015  59 31   8.6   4.7 | -30.7 -23.3  005  49 25   8.2   4.5
 24000 -28.8 -19.8  015  57 29   8.3   4.5 | -28.2 -18.8  005  47 24   8.5   4.7
 23000 -26.4 -15.5  015  55 28   8.1   4.5 | -25.6 -14.1  005  43 22   8.5   4.7
 22000 -23.9 -11.0  015  53 27   8.2   4.5 | -23.1  -9.6  005  40 21   8.5   4.7
 21000 -21.5  -6.7  015  50 26   8.0   4.4 | -20.6  -5.1  010  37 19   7.7   4.2
 20000 -19.1  -2.4  015  48 25   8.0   4.4 | -18.3  -0.9  010  35 18   7.8   4.3
 19500 -17.9  -0.2  015  47 24   8.0   4.4 | -17.1   1.2  010  34 18   7.8   4.3
 19000 -16.7   1.9  015  46 24   8.1   4.5 | -16.0   3.2  010  33 17   7.9   4.3
 18500 -15.6   3.9  015  45 23   6.4   3.5 | -14.8   5.4  010  33 17   6.9   3.8
 18000 -14.7   5.5  015  42 21   6.1   3.4 | -13.8   7.2  010  32 16   6.8   3.8
 17500 -13.8   7.2  015  39 20   5.7   3.1 | -12.8   9.0  005  32 16   6.8   3.7
 17000 -13.0   8.6  015  35 18   4.4   2.4 | -11.8  10.8  005  31 16   6.8   3.7
 16500 -12.4   9.7  010  32 16   4.4   2.4 | -10.8  12.6  005  31 16   7.1   3.9
 16000 -11.6  11.1  010  29 15   5.6   3.1 |  -9.9  14.2  005  30 15   4.0   2.2
 15500 -10.8  12.6  010  26 14   5.5   3.0 |  -9.3  15.3  360  29 15   4.2   2.3
 15000 -10.0  14.0  010  24 12   6.1   3.3 |  -8.7  16.3  360  28 14   4.4   2.4
 14500  -9.0  15.8  010  23 12   6.3   3.5 |  -8.1  17.4  360  27 14   4.5   2.5
 14000  -8.1  17.4  010  22 11   6.7   3.7 |  -7.4  18.7  005  25 13   4.9   2.7
 13500  -7.0  19.4  010  21 11   7.0   3.9 |  -6.6  20.1  005  24 12   5.4   2.9
 13000  -5.5  22.1  010  20 10   6.6   3.6 |  -5.4  22.3  005  22 11   5.7   3.1
 12500  -4.5  23.9  015  20 10   6.9   3.8 |  -4.6  23.7  005  20 10   5.8   3.2
 12000  -3.7  25.3  015  19 10   2.9   1.6 |  -3.9  25.0  005  18  9   4.3   2.4
 11500  -3.4  25.9  015  19 10   2.5   1.4 |  -3.4  25.9  005  15  8   4.2   2.3
 11000  -3.1  26.4  010  19 10   3.9   2.1 |  -2.7  27.1  005  12  6   6.6   3.6
 10500  -2.6  27.3  010  15  8   4.3   2.4 |  -1.8  28.8  360  11  6   7.3   4.0
 10250  -2.4  27.7  010  14  7   4.3   2.4 |  -1.3  29.7  360  10  5   5.4   3.0
 10000  -2.0  28.4  010  13  7   7.3   4.0 |  -0.9  30.4  360   9  5   7.2   4.0
  9750  -1.3  29.7  005  13  7   9.6   5.2 |  -0.2  31.6  360   9  5  10.5   5.8
  9500  -0.7  30.7  005  13  6   9.3   5.1 |   0.5  32.9  360   9  5   9.7   5.3
  9250  -0.0  32.0  005  12  6   8.2   4.5 |   1.3  34.3  360   8  4   9.5   5.2
  9000   0.5  32.9  005  12  6   8.9   4.9 |   1.9  35.4  360   8  4   9.4   5.1
  8750   1.3  34.3  005  12  6  10.8   5.9 |   2.7  36.9  360   8  4   9.8   5.4
  8500   2.1  35.8  005  11  6  10.3   5.6 |   3.4  38.1  360   7  4   9.7   5.3
  8250   2.9  37.2  005  11  6  10.8   5.9 |   4.1  39.4  360   7  4  10.0   5.5
  8000   3.7  38.7  005  11  6  10.4   5.7 |   4.9  40.8  360   7  3   9.9   5.4
  7750   4.4  39.9  005  11  5   9.7   5.3 |   5.6  42.1  360   6  3   9.4   5.1
  7500   5.1  41.2  005  10  5  10.0   5.5 |   6.3  43.3  360   6  3   9.9   5.4
  7250   5.9  42.6  005  10  5  10.5   5.8 |   7.1  44.8  360   6  3  10.8   5.9
  7000   6.7  44.1  005  10  5  10.2   5.6 |   7.9  46.2  360   6  3  10.4   5.7
  6750   7.4  45.3  005  10  5   9.6   5.3 |   8.6  47.5  360   6  3   9.3   5.1
  6500   8.2  46.8  005   9  5  10.6   5.8 |   9.3  48.7  360   5  3   9.9   5.4
  6250   9.0  48.2  005   9  5  12.0   6.6 |  10.1  50.2  360   5  3  10.7   5.9
  6000   9.9  49.8  005   9  5  10.2   5.6 |  10.9  51.6  360   5  2  10.3   5.7
  5750  10.6  51.1  005   8  4  12.1   6.6 |  11.6  52.9  360   5  2   9.7   5.3
  5500  11.7  53.1  005   8  4  16.1   8.8 |  12.3  54.1  360   5  2   9.4   5.2
  5250  12.9  55.2  005   9  4  13.9   7.6 |  13.0  55.4  360   5  3   9.7   5.3
  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.