Soaring Guidance
Issued by NWS Denver/Boulder, 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 15 16 17 18 19 20 21 22 23 24 25 26 27 28
000
UXUS97 KBOU 031151
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0551 MDT Tuesday, May 3, 2016

This forecast is for Tuesday, May 3, 2016:

If the trigger temperature of 54.8 F/12.6 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 1038 ft/min (5.3 m/s)
   Maximum height of thermals.................. 17223 ft MSL (11916 ft AGL)

Forecast maximum temperature................... 67.0 F/19.9 C
Time of trigger temperature.................... 0900 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................. 14929 ft MSL (9622 ft AGL)
Thermal soaring outlook for Wednesday 05/04.... Excellent

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 20038 ft MSL (14731 ft AGL)
Wave soaring outlook for Wednesday 05/04....... Poor

Remarks... Large high pressure ridge over the great basin shifts east over
           colorado during the next 24 hours.

Sunrise/Sunset.................... 05:57:01 / 19:55:22 MDT
Total possible sunshine........... 13 hr 58 min 22 sec (838 min 22 sec)
Altitude of sun at 12:56:22 MDT... 66.19 degrees

Upper air data from numerical model forecast valid on 05/03/2016 at 0600 MDT

Freezing level.................. 9567 ft MSL (4260 ft AGL)
Convective condensation level... 11247 ft MSL (5940 ft AGL)
Lifted condensation level....... 13603 ft MSL (8296 ft AGL)
Lifted index.................... -1.5
K index......................... +7.7

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  -57.3 -71.1   295   27   14   1.1   0.6      M     M       M      M    M
 45000  -55.6 -68.1   300   30   16   0.4   0.2      M     M       M      M    M
 40000  -57.3 -71.1   350   28   14  -1.1  -0.6      M     M       M      M    M
 38000  -56.7 -70.1   010   34   17   2.9   1.6      M     M       M      M    M
 36000  -54.9 -66.8   025   45   23   2.9   1.6      M     M       M      M    M
 34000  -52.8 -63.0   035   56   29   6.5   3.5      M     M       M      M    M
 32000  -49.1 -56.4   030   60   31   6.3   3.4      M     M       M      M    M
 30000  -45.2 -49.4   030   63   32   7.7   4.2   31.2  88.2     8.8      M    M
 29000  -42.8 -45.0   025   63   33   7.7   4.2   30.3  86.5     8.2      M    M
 28000  -40.0 -40.0   025   64   33   7.7   4.2   29.3  84.8     7.6      M    M
 27000  -37.6 -35.7   025   64   33   8.4   4.6   28.7  83.6     7.2      M    M
 26000  -35.1 -31.2   025   64   33   8.5   4.7   28.1  82.6     6.8      M    M
 25000  -32.5 -26.5   025   64   33   8.5   4.7   27.6  81.8     6.6      M    M
 24000  -30.0 -22.0   025   64   33   8.2   4.5   27.3  81.1     6.3      M    M
 23000  -27.6 -17.7   025   61   31   7.9   4.3   26.5  79.7     5.8      M    M
 22000  -25.3 -13.5   020   58   30   7.9   4.3   25.8  78.5     5.3      M    M
 21000  -23.1  -9.6   020   54   28   5.4   2.9   25.1  77.1     4.7      M    M
 20000  -21.5  -6.7   015   49   25   5.3   2.9   23.4  74.1     3.4      M    M
 19500  -20.7  -5.3   015   47   24   5.3   2.9   22.6  72.8     2.7      M    M
 19000  -19.9  -3.8   010   44   23   5.3   2.9   21.9  71.4     2.1      M    M
 18500  -19.1  -2.4   010   42   22   5.9   3.2   21.2  70.2     1.5      M    M
 18000  -18.2  -0.8   005   41   21   6.1   3.4   20.6  69.0     1.0      M    M
 17500  -17.2   1.0   005   41   21   6.0   3.3   20.0  67.9     0.4      M    M
 17000  -16.4   2.5   005   39   20   5.6   3.1   19.3  66.7    -0.2   1027  5.2
 16500  -15.5   4.1   360   38   19   5.7   3.1   18.6  65.4    -0.8    987  5.0
 16000  -14.7   5.5   360   36   18   5.3   2.9   17.9  64.1    -1.4    948  4.8
 15500  -13.9   7.0   355   34   17   5.4   3.0   17.1  62.8    -2.1    910  4.6
 15000  -12.6   9.3   355   30   16   6.9   3.8   16.2  61.1    -3.0    849  4.3
 14500  -11.7  10.9   350   29   15   6.8   3.8   15.7  60.3    -3.5    804  4.1
 14000  -10.6  12.9   345   28   14   7.7   4.2   15.3  59.5    -4.0    758  3.9
 13500   -9.5  14.9   345   27   14   7.5   4.1   14.9  58.9    -4.4    710  3.6
 13000   -8.3  17.1   345   27   14   8.7   4.8   14.7  58.4    -4.7    660  3.4
 12500   -7.1  19.2   345   27   14   8.8   4.8   14.5  58.1    -4.9    608  3.1
 12000   -5.8  21.6   345   27   14   8.7   4.8   14.4  57.9    -5.1    556  2.8
 11500   -4.6  23.7   345   27   14   8.8   4.8   14.2  57.6    -5.4    504  2.6
 11000   -3.3  26.1   345   28   14   9.0   4.9   14.1  57.3    -5.6    451  2.3
 10500   -2.0  28.4   345   27   14  10.1   5.5   13.9  57.0    -5.8    398  2.0
 10250   -1.4  29.5   345   27   14   4.6   2.5   13.9  56.9    -5.9    371  1.9
 10000   -1.2  29.8   345   27   14   5.5   3.0   13.3  55.9    -6.5    359  1.8
  9750   -0.5  31.1   350   27   14  11.6   6.3   13.3  56.0    -6.5    329  1.7
  9500    0.3  32.5   350   26   13  10.2   5.6   13.4  56.0    -6.5    299  1.5
  9250    1.0  33.8   350   26   13   7.6   4.2   13.4  56.0    -6.5    271  1.4
  9000    1.4  34.5   355   26   13   6.1   3.4   13.1  55.5    -6.8    251  1.3
  8750    1.9  35.4   355   25   13   8.7   4.8   12.9  55.2    -7.0    227  1.2
  8500    2.6  36.7   360   25   13   8.9   4.9   12.8  55.1    -7.1    200  1.0
  8250    3.2  37.8   360   25   13   8.6   4.7   12.8  55.0    -7.3    174  0.9
  8000    3.8  38.8   360   25   13   8.5   4.6   12.7  54.8    -7.4    148  0.8
  7750    4.5  40.1   005   25   13   9.1   5.0   12.6  54.6    -7.5    122  0.6
  7500    5.1  41.2   005   24   13   8.6   4.7   12.5  54.5    -7.6     94  0.5
  7250    5.7  42.3   005   24   12   7.6   4.2   12.4  54.3    -7.7     69  0.4
  7000    6.3  43.3   005   23   12   8.0   4.4   12.2  54.0    -7.9     44  0.2
  6750    6.9  44.4   005   23   12   7.1   3.9   12.1  53.8    -8.0     19  0.1
  6500    7.3  45.1   360   21   11   3.5   1.9   11.8  53.2    -8.4      M    M
  6250    7.6  45.7   355   19   10   2.5   1.4   11.2  52.2    -8.9      M    M
  6000    7.8  46.0   350   18    9   0.9   0.5   10.6  51.2    -9.4      M    M
  5750    7.4  45.3   345   15    7 -14.4  -7.9    9.5  49.2   -10.6      M    M
  5500    5.5  41.9   325    8    4 -32.8 -18.0    7.0  44.5   -13.3     26  0.1

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

           05/03/2016 at 0900 MDT          |       05/03/2016 at 1200 MDT
                                           |
K index... -5.7  LI... +2.6                | K index... -18.1  LI... +2.0
CAPE... +4.6  CIN... -4.5                  | CAPE... +1.1  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 -57.8 -72.0  300  28 14   1.2   0.7 | -58.0 -72.4  305  26 14   1.0   0.6
 45000 -56.0 -68.8  310  29 15   0.1   0.0 | -56.7 -70.1  320  27 14  -3.1  -1.7
 40000 -58.6 -73.5  025  25 13  -1.7  -0.9 | -60.9 -77.6  040  28 15  -2.9  -1.6
 38000 -57.8 -72.0  040  34 17   3.5   1.9 | -59.4 -74.9  050  35 18   5.7   3.1
 36000 -55.7 -68.3  045  43 22   3.5   1.9 | -56.0 -68.8  050  40 20   5.7   3.1
 34000 -53.1 -63.6  045  51 26   7.1   3.9 | -52.3 -62.1  050  42 22   7.3   4.0
 32000 -48.9 -56.0  040  50 26   7.1   3.9 | -47.9 -54.2  045  39 20   7.3   4.0
 30000 -44.6 -48.3  040  49 25   7.7   4.2 | -43.1 -45.6  045  37 19   6.9   3.8
 29000 -41.7 -43.1  035  50 26   7.7   4.2 | -41.0 -41.8  045  37 19   6.9   3.8
 28000 -39.4 -38.9  035  50 26   7.7   4.2 | -39.0 -38.2  045  37 19   6.9   3.8
 27000 -37.0 -34.6  035  51 26   8.6   4.7 | -36.8 -34.2  040  37 19   8.5   4.7
 26000 -34.5 -30.1  035  52 27   8.6   4.7 | -34.3 -29.7  040  38 20   8.4   4.6
 25000 -31.9 -25.4  035  53 27   8.6   4.7 | -31.8 -25.2  040  39 20   8.4   4.6
 24000 -29.4 -20.9  035  54 28   8.2   4.5 | -29.2 -20.6  040  40 20   8.5   4.7
 23000 -26.9 -16.4  035  53 27   8.1   4.4 | -26.7 -16.1  040  40 21   8.5   4.7
 22000 -24.5 -12.1  035  51 26   8.1   4.4 | -24.2 -11.6  040  40 21   8.5   4.7
 21000 -22.3  -8.1  035  50 26   5.6   3.1 | -21.8  -7.2  040  40 20   7.2   4.0
 20000 -20.5  -4.9  035  46 23   5.9   3.2 | -19.5  -3.1  040  39 20   7.3   4.0
 19500 -19.6  -3.3  030  44 22   5.9   3.2 | -18.4  -1.1  040  39 20   7.3   4.0
 19000 -18.7  -1.7  030  42 21   5.9   3.2 | -17.3   0.9  040  39 20   7.4   4.1
 18500 -17.8  -0.0  030  40 20   6.0   3.3 | -16.3   2.7  040  38 20   6.7   3.7
 18000 -16.9   1.6  025  38 19   6.0   3.3 | -15.2   4.6  040  37 19   6.8   3.7
 17500 -16.0   3.2  025  36 18   6.1   3.4 | -14.2   6.4  040  36 18   6.4   3.5
 17000 -15.1   4.8  025  34 18   6.4   3.5 | -13.3   8.1  035  34 17   6.1   3.3
 16500 -14.1   6.6  020  32 17   6.5   3.5 | -12.4   9.7  035  32 16   6.1   3.3
 16000 -13.2   8.2  020  31 16   5.8   3.2 | -11.4  11.5  030  30 15   6.4   3.5
 15500 -12.4   9.7  020  30 15   5.9   3.2 | -10.0  14.0  025  27 14   5.9   3.2
 15000 -11.2  11.8  020  29 15   5.0   2.8 |  -9.3  15.3  025  25 13   4.8   2.6
 14500 -10.4  13.3  015  28 14   5.1   2.8 |  -8.5  16.7  020  23 12   4.9   2.7
 14000  -9.6  14.7  010  27 14   5.9   3.3 |  -7.7  18.1  020  22 11   5.9   3.2
 13500  -8.8  16.2  005  26 13   5.8   3.2 |  -6.9  19.6  015  21 11   5.8   3.2
 13000  -7.8  18.0  005  26 13   7.0   3.8 |  -6.5  20.3  015  21 11   6.5   3.6
 12500  -6.9  19.6  360  25 13   6.9   3.8 |  -5.0  23.0  010  20 10   6.5   3.6
 12000  -5.8  21.6  355  25 13   7.8   4.3 |  -4.1  24.6  010  20 10   5.3   2.9
 11500  -4.7  23.5  355  25 13   7.8   4.3 |  -3.3  26.1  010  20 10   5.4   3.0
 11000  -3.6  25.5  355  25 13   8.1   4.4 |  -2.5  27.5  005  20 10   6.0   3.3
 10500  -2.5  27.5  355  25 13   9.1   5.0 |  -1.7  28.9  360  20 10   6.7   3.6
 10250  -1.9  28.6  355  26 13   3.5   1.9 |  -1.4  29.5  360  19 10   3.2   1.8
 10000  -1.8  28.8  355  26 13   5.7   3.1 |  -1.2  29.8  355  19 10   6.6   3.6
  9750  -1.0  30.2  355  26 13  12.7   7.0 |  -0.5  31.1  355  18  9  12.4   6.8
  9500  -0.2  31.6  360  26 13  10.7   5.8 |   0.2  32.4  350  17  9  10.6   5.8
  9250   0.5  32.9  360  26 13   8.2   4.5 |   0.9  33.6  350  16  8   8.0   4.4
  9000   1.0  33.8  360  25 13   7.5   4.1 |   1.4  34.5  350  16  8   8.3   4.6
  8750   1.7  35.1  360  25 13  10.2   5.6 |   2.2  36.0  350  16  8  12.1   6.6
  8500   2.4  36.3  360  25 13  10.0   5.5 |   3.0  37.4  350  16  8  11.2   6.2
  8250   3.1  37.6  360  25 13   8.9   4.9 |   3.8  38.8  350  16  8   9.3   5.1
  8000   3.8  38.8  360  25 13   8.9   4.9 |   4.5  40.1  350  16  8   9.6   5.3
  7750   4.5  40.1  360  25 13  10.5   5.8 |   5.2  41.4  350  16  8  10.6   5.8
  7500   5.3  41.5  360  25 13   9.6   5.3 |   6.0  42.8  350  16  8  10.4   5.7
  7250   5.9  42.6  360  25 13   7.6   4.2 |   6.8  44.2  350  15  8   9.6   5.3
  7000   6.5  43.7  360  24 13   8.4   4.6 |   7.5  45.5  350  15  8   9.8   5.4
  6750   7.1  44.8  360  24 13   7.1   3.9 |   8.2  46.8  350  15  8  10.3   5.6
  6500   7.6  45.7  355  23 12   5.5   3.0 |   9.0  48.2  345  15  8  10.5   5.8
  6250   7.9  46.2  355  19 10   4.7   2.6 |   9.8  49.6  345  15  8  10.4   5.7
  6000   8.3  46.9  350  16  8   6.7   3.7 |  10.5  50.9  345  14  7  10.2   5.6
  5750   9.0  48.2  345  13  7  11.5   6.3 |  11.4  52.5  345  14  7  15.1   8.3
  5500   9.9  49.8  340  10  5  13.3   7.3 |  12.8  55.0  345  13  7  23.9  13.1

           05/03/2016 at 1500 MDT          |       05/03/2016 at 1800 MDT
                                           |
K index... -8.0  LI... +0.9                | K index... +1.1  LI... 0.0
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -1.4
                                           |
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 -59.0 -74.2  305  25 13   0.9   0.5 | -59.8 -75.6  305  26 13   0.3   0.2
 45000 -57.8 -72.0  325  25 13  -2.4  -1.3 | -59.4 -74.9  330  21 11  -1.2  -0.7
 40000 -60.9 -77.6  025  28 14  -2.0  -1.1 | -61.0 -77.8  025  26 13  -1.0  -0.5
 38000 -59.0 -74.2  030  31 16   5.8   3.2 | -58.6 -73.5  030  29 15   6.1   3.4
 36000 -55.6 -68.1  035  34 18   5.8   3.2 | -55.0 -67.0  035  32 16   6.1   3.4
 34000 -51.8 -61.2  040  35 18   7.4   4.0 | -51.0 -59.8  035  32 17   7.4   4.1
 32000 -47.4 -53.3  040  32 16   7.4   4.1 | -46.0 -50.8  030  29 15   7.4   4.1
 30000 -42.5 -44.5  040  29 15   6.9   3.8 | -41.7 -43.1  025  26 13   7.1   3.9
 29000 -40.4 -40.7  040  28 14   6.9   3.8 | -39.5 -39.1  020  25 13   7.1   3.9
 28000 -38.4 -37.1  040  26 14   6.9   3.8 | -37.4 -35.3  020  24 12   7.1   3.9
 27000 -36.1 -33.0  035  26 13   8.4   4.6 | -35.2 -31.4  020  24 12   7.6   4.2
 26000 -33.6 -28.5  035  27 14   8.3   4.6 | -33.0 -27.4  020  24 12   7.6   4.1
 25000 -31.1 -24.0  035  28 15   8.4   4.6 | -30.7 -23.3  020  24 12   7.6   4.2
 24000 -28.7 -19.7  035  30 15   8.1   4.4 | -28.4 -19.1  025  24 12   8.4   4.6
 23000 -26.3 -15.3  035  30 16   8.1   4.4 | -25.9 -14.6  030  25 13   8.3   4.6
 22000 -23.9 -11.0  035  31 16   8.1   4.5 | -23.4 -10.1  030  25 13   8.3   4.6
 21000 -21.5  -6.7  035  31 16   7.6   4.1 | -21.1  -6.0  035  25 13   7.4   4.0
 20000 -19.3  -2.7  035  30 15   7.6   4.2 | -18.9  -2.0  035  24 12   7.4   4.1
 19500 -18.1  -0.6  040  29 15   7.6   4.2 | -17.8  -0.0  035  23 12   7.4   4.1
 19000 -17.0   1.4  040  29 15   7.6   4.2 | -16.7   1.9  035  22 11   7.5   4.1
 18500 -15.9   3.4  040  28 15   7.8   4.3 | -15.5   4.1  030  21 11   8.4   4.6
 18000 -14.7   5.5  040  28 14   7.8   4.3 | -14.3   6.3  030  20 10   8.4   4.6
 17500 -13.5   7.7  040  28 14   7.9   4.3 | -13.0   8.6  025  19 10   7.8   4.3
 17000 -12.3   9.9  040  27 14   7.9   4.3 | -11.9  10.6  020  18  9   7.6   4.2
 16500 -11.1  12.0  035  26 13   7.7   4.2 | -10.2  13.6  015  18  9   8.0   4.4
 16000  -9.6  14.7  035  24 13   6.5   3.6 |  -9.0  15.8  015  18  9   8.0   4.4
 15500  -8.5  16.7  030  23 12   6.6   3.6 |  -7.8  18.0  010  18  9   7.6   4.2
 15000  -7.5  18.5  025  22 11   6.6   3.6 |  -6.7  19.9  010  18  9   7.3   4.0
 14500  -6.5  20.3  025  21 11   6.1   3.3 |  -5.6  21.9  010  18  9   6.9   3.8
 14000  -5.8  21.6  020  21 11   3.9   2.2 |  -4.6  23.7  010  18  9   5.8   3.2
 13500  -5.2  22.6  015  20 10   4.2   2.3 |  -3.7  25.3  010  18  9   5.9   3.2
 13000  -4.4  24.1  010  19 10   5.5   3.0 |  -2.9  26.8  010  18  9   5.5   3.0
 12500  -3.6  25.5  010  19 10   5.5   3.0 |  -2.0  28.4  005  18  9   5.5   3.0
 12000  -2.7  27.1  005  18  9   7.0   3.8 |  -1.1  30.0  005  17  9   7.2   3.9
 11500  -1.7  28.9  360  17  9   6.9   3.8 |  -0.0  32.0  005  17  9   7.1   3.9
 11000  -0.7  30.7  355  16  8   7.4   4.1 |   1.0  33.8  360  17  9   7.6   4.2
 10500   0.3  32.5  355  15  8   7.4   4.1 |   2.2  36.0  360  16  8   7.2   3.9
 10250   0.7  33.3  350  15  8   3.4   1.9 |   2.6  36.7  360  16  8   3.5   1.9
 10000   1.6  34.9  350  14  7   6.6   3.6 |   2.8  37.0  360  16  8   6.9   3.8
  9750   1.7  35.1  350  14  7  12.1   6.6 |   3.6  38.5  360  15  8  11.8   6.5
  9500   2.4  36.3  350  13  7  10.2   5.6 |   4.4  39.9  360  15  8   9.5   5.2
  9250   2.9  37.2  350  13  7   7.3   4.0 |   4.9  40.8  360  14  7   6.2   3.4
  9000   3.4  38.1  350  12  6   7.8   4.3 |   5.2  41.4  355  13  7   5.9   3.3
  8750   4.1  39.4  350  12  6  11.1   6.1 |   5.7  42.3  355  12  6   7.9   4.3
  8500   4.8  40.6  350  12  6  10.4   5.7 |   6.2  43.2  355  11  6   8.0   4.4
  8250   5.6  42.1  350  12  6   9.3   5.1 |   6.7  44.1  350  10  5   8.1   4.5
  8000   6.2  43.2  350  12  6   9.6   5.3 |   7.2  45.0  345  10  5   8.4   4.6
  7750   7.0  44.6  345  12  6  10.6   5.8 |   7.8  46.0  340   9  5   9.3   5.1
  7500   7.8  46.0  345  12  6  10.4   5.7 |   8.5  47.3  335   9  5   9.6   5.3
  7250   8.5  47.3  345  12  6   9.7   5.3 |   9.2  48.6  335   9  4   9.4   5.2
  7000   9.2  48.6  345  11  6   9.9   5.4 |   9.9  49.8  335   9  4   9.5   5.2
  6750  10.0  50.0  345  11  6  10.2   5.6 |  10.7  51.3  330   8  4  10.1   5.5
  6500  10.8  51.4  345  11  6  10.4   5.7 |  11.4  52.5  330   8  4  10.2   5.6
  6250  11.5  52.7  345  11  6  10.1   5.5 |  12.1  53.8  330   8  4   9.7   5.3
  6000  12.3  54.1  345  11  6  10.9   6.0 |  12.9  55.2  325   8  4  10.4   5.7
  5750  13.2  55.8  340  10  5  15.4   8.5 |  13.7  56.7  325   8  4  11.6   6.3
  5500  14.5  58.1  340  10  5  20.3  11.2 |  14.5  58.1  325   7  4  11.6   6.4
________________________________________________________________________________

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 old Stapleton
Airport site in Denver, Colorado at

                   North Latitude:  39 deg 46 min 5.016 sec
                   West Longitude: 104 deg 52 min 9.984 sec
                   Elevation: 5285 feet (1611 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.