Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Graphics & Text | 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
000
UXUS97 KBOU 250142
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1842 MST Saturday, January 24, 2015

This forecast is for Sunday, January 25, 2015:

If the trigger temperature of 50.2 F/10.1 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 611 ft/min (3.1 m/s)
   Maximum height of thermals.................. 13096 ft MSL (7809 ft AGL)

Forecast maximum temperature................... 58.0 F/14.9 C
Time of trigger temperature.................... 1030 MST
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................. 10237 ft MSL (4950 ft AGL)
Thermal soaring outlook for Monday 01/26....... Fair

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1700 MST)................ Weak NVA
Potential height of wave....................... 26412 ft MSL (21125 ft AGL)
Wave soaring outlook for Monday 01/26.......... Poor

Remarks...

Sunrise/Sunset.................... 07:13:11 / 17:09:27 MST
Total possible sunshine........... 9 hr 56 min 16 sec (596 min 16 sec)
Altitude of sun at 12:11:42 MST... 31.39 degrees

Upper air data from numerical model forecast valid on 01/25/2015 at 0500 MST

Freezing level.................. 5332 ft MSL (45 ft AGL)
Additional freezing level....... 8120 ft MSL (2833 ft AGL)
Convective condensation level... 15001 ft MSL (9714 ft AGL)
Lifted condensation level....... 13898 ft MSL (8610 ft AGL)
Lifted index.................... +5.6
K index......................... +2.9

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  -58.5 -73.3   325   25   13   3.7   2.0      M     M       M      M    M
 45000  -52.9 -63.2   340   42   22   0.6   0.3      M     M       M      M    M
 40000  -59.5 -75.1   345   84   43  -4.2  -2.3      M     M       M      M    M
 38000  -59.5 -75.1   350   90   47   3.9   2.1      M     M       M      M    M
 36000  -57.1 -70.8   005   92   47   3.9   2.1      M     M       M      M    M
 34000  -54.3 -65.7   015   97   50   8.7   4.8      M     M       M      M    M
 32000  -49.2 -56.6   015  106   55   8.5   4.6      M     M       M      M    M
 30000  -44.1 -47.4   010  112   57   8.5   4.7   32.6  90.7    13.6      M    M
 29000  -41.6 -42.9   010  107   55   8.5   4.7   32.0  89.6    13.3      M    M
 28000  -38.4 -37.1   005  102   52   8.5   4.7   31.4  88.6    13.1      M    M
 27000  -35.9 -32.6   005   97   50   7.3   4.0   31.0  87.8    12.9      M    M
 26000  -33.7 -28.7   360   93   48   7.2   3.9   29.9  85.8    12.2      M    M
 25000  -31.6 -24.9   355   89   46   7.2   3.9   29.0  84.1    11.6      M    M
 24000  -29.5 -21.1   350   85   44   7.3   4.0   28.1  82.6    11.0      M    M
 23000  -27.3 -17.1   350   82   42   7.4   4.0   27.1  80.8    10.4      M    M
 22000  -25.1 -13.2   345   78   40   7.4   4.1   26.3  79.3     9.8      M    M
 21000  -22.9  -9.2   345   75   39   6.7   3.7   25.5  77.8     9.2      M    M
 20000  -20.9  -5.6   345   71   36   6.7   3.7   24.3  75.8     8.3      M    M
 19500  -19.9  -3.8   340   69   35   6.7   3.7   23.8  74.8     7.9      M    M
 19000  -18.9  -2.0   340   67   34   6.7   3.7   23.3  73.9     7.5      M    M
 18500  -18.0  -0.4   340   65   33   5.8   3.2   22.8  73.0     7.1      M    M
 18000  -17.2   1.0   335   62   32   5.5   3.0   22.0  71.6     6.4      M    M
 17500  -16.4   2.5   335   60   31   5.6   3.1   21.3  70.3     5.8      M    M
 17000  -15.5   4.1   330   58   30   6.8   3.7   20.7  69.2     5.3      M    M
 16500  -14.4   6.1   330   55   28   6.9   3.8   20.2  68.3     4.9      M    M
 16000  -13.5   7.7   325   52   27   5.5   3.0   19.6  67.2     4.4      M    M
 15500  -12.7   9.1   325   49   25   5.5   3.0   18.8  65.9     3.8      M    M
 15000  -11.9  10.6   325   47   24   4.9   2.7   18.1  64.6     3.1      M    M
 14500  -11.2  11.8   325   47   24   4.5   2.5   17.2  63.0     2.4      M    M
 14000  -10.2  13.6   330   46   24   4.7   2.6   15.9  60.7     1.2      M    M
 13500   -9.5  14.9   330   45   23   4.6   2.5   15.1  59.2     0.4      M    M
 13000   -8.7  16.3   335   44   23   6.0   3.3   14.4  57.9    -0.3    595  3.0
 12500   -7.8  18.0   335   42   22   6.1   3.3   13.8  56.8    -0.8    553  2.8
 12000   -6.9  19.6   335   41   21   7.6   4.2   13.3  56.0    -1.3    510  2.6
 11500   -5.7  21.7   335   40   21   8.0   4.4   13.0  55.4    -1.6    460  2.3
 11000   -4.7  23.5   335   38   20   5.9   3.2   12.6  54.7    -2.1    414  2.1
 10500   -3.9  25.0   335   34   18   6.2   3.4   11.9  53.5    -2.7    375  1.9
 10250   -3.5  25.7   335   32   17   3.4   1.9   11.6  52.9    -3.1    356  1.8
 10000   -3.3  26.1   335   32   16   4.1   2.3   11.0  51.9    -3.6    343  1.7
  9750   -2.8  27.0   330   30   16   8.1   4.4   10.8  51.5    -3.8    321  1.6
  9500   -2.2  28.0   325   29   15   8.2   4.5   10.7  51.2    -4.0    296  1.5
  9250   -1.6  29.1   325   27   14   6.1   3.3   10.5  50.9    -4.2    272  1.4
  9000   -1.3  29.7   320   27   14   4.3   2.3   10.1  50.2    -4.6    254  1.3
  8750   -0.9  30.4   320   26   13   5.9   3.2    9.7  49.5    -5.0    236  1.2
  8500   -0.5  31.1   315   26   13   5.7   3.1    9.5  49.0    -5.3    215  1.1
  8250   -0.1  31.8   315   26   13   4.2   2.3    9.1  48.4    -5.6    197  1.0
  8000    0.1  32.2   310   26   13   3.7   2.0    8.6  47.5    -6.1    182  0.9
  7750    0.4  32.7   310   25   13   3.5   1.9    8.2  46.7    -6.6    166  0.8
  7500    0.7  33.3   310   25   13   4.0   2.2    7.7  45.8    -7.1    151  0.8
  7250    1.0  33.8   310   23   12   4.8   2.6    7.3  45.1    -7.5    134  0.7
  7000    1.3  34.3   310   21   11   4.6   2.5    6.9  44.4    -7.9    116  0.6
  6750    1.7  35.1   310   19   10   4.7   2.6    6.5  43.7    -8.3     99  0.5
  6500    2.0  35.6   310   16    8   4.3   2.4    6.1  43.0    -8.7     81  0.4
  6250    2.4  36.3   310   14    7   5.0   2.8    5.7  42.3    -9.2     64  0.3
  6000    2.7  36.9   310   11    6   1.9   1.0    5.3  41.6    -9.6     46  0.2
  5750    2.4  36.3   305    9    5 -10.9  -6.0    4.3  39.8   -10.6     48  0.2
  5500    1.1  34.0   280    6    3 -22.3 -12.2    2.3  36.1   -12.6     80  0.4

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

           01/25/2015 at 0800 MST          |       01/25/2015 at 1100 MST
                                           |
K index... +3.4  LI... +8.9                | K index... +3.6  LI... +8.1
CAPE... 0.0  CIN... -1.0                   | CAPE... 0.0  CIN... -0.2
                                           |
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 -58.3 -72.9  335  23 12   4.4   2.4 | -58.7 -73.7  330  27 14   4.3   2.4
 45000 -51.6 -60.9  345  40 21   0.4   0.2 | -52.7 -62.9  345  42 21  -8.6  -4.7
 40000 -60.5 -76.9  355  80 41  -5.7  -3.1 | -63.8 -82.8  355  71 37  -7.5  -4.1
 38000 -60.6 -77.1  360  84 43   4.2   2.3 | -62.7 -80.9  360  73 37   7.7   4.2
 36000 -58.1 -72.6  015  85 44   4.3   2.3 | -58.1 -72.6  005  67 35   7.7   4.2
 34000 -54.9 -66.8  025  88 46   8.6   4.7 | -53.3 -63.9  005  65 33   8.8   4.8
 32000 -49.8 -57.6  015  82 42   8.6   4.7 | -48.0 -54.4  010  68 35   8.8   4.8
 30000 -44.5 -48.1  005  78 40   9.4   5.2 | -42.0 -43.6  015  70 36   9.1   5.0
 29000 -41.0 -41.8  360  75 38   9.4   5.2 | -39.3 -38.7  015  69 35   9.1   5.0
 28000 -38.2 -36.8  360  72 37   9.5   5.2 | -36.5 -33.7  015  68 35   9.1   5.0
 27000 -35.4 -31.7  355  71 37   8.3   4.6 | -33.9 -29.0  015  67 34   8.6   4.7
 26000 -32.9 -27.2  355  71 37   8.4   4.6 | -31.3 -24.3  015  66 34   8.7   4.7
 25000 -30.4 -22.7  355  71 37   8.4   4.6 | -28.7 -19.7  010  66 34   8.7   4.8
 24000 -27.8 -18.0  355  72 37   7.9   4.4 | -26.2 -15.2  010  65 33   6.8   3.7
 23000 -25.5 -13.9  355  70 36   7.8   4.3 | -24.1 -11.4  005  60 31   6.9   3.8
 22000 -23.2  -9.8  355  69 36   7.8   4.3 | -22.1  -7.8  360  57 29   6.9   3.8
 21000 -20.9  -5.6  350  68 35   7.4   4.0 | -19.9  -3.8  355  55 28   8.1   4.4
 20000 -18.7  -1.7  350  67 34   7.5   4.1 | -17.5   0.5  350  53 27   8.0   4.4
 19500 -17.6   0.3  350  66 34   7.5   4.1 | -16.3   2.7  350  52 27   8.0   4.4
 19000 -16.5   2.3  350  66 34   7.6   4.2 | -15.1   4.8  350  52 27   8.1   4.5
 18500 -15.5   4.1  350  65 33   5.5   3.0 | -14.0   6.8  345  50 26   6.9   3.8
 18000 -14.7   5.5  345  63 33   5.2   2.8 | -13.0   8.6  345  48 25   6.9   3.8
 17500 -13.9   7.0  345  61 32   4.9   2.7 | -11.9  10.6  345  47 24   6.1   3.3
 17000 -13.3   8.1  340  59 30   4.1   2.3 | -11.2  11.8  340  47 24   4.9   2.7
 16500 -12.7   9.1  340  56 29   4.0   2.2 | -10.5  13.1  340  48 25   4.9   2.7
 16000 -12.0  10.4  335  54 28   6.6   3.6 |  -9.8  14.4  340  47 24   5.0   2.7
 15500 -11.0  12.2  335  52 27   6.5   3.6 |  -9.1  15.6  335  45 23   5.0   2.7
 15000 -10.1  13.8  335  51 26   5.0   2.7 |  -8.0  17.6  330  44 22   4.8   2.7
 14500  -9.1  15.6  335  49 25   4.6   2.5 |  -7.3  18.9  330  43 22   4.9   2.7
 14000  -8.6  16.5  335  48 25   2.7   1.5 |  -6.6  20.1  330  41 21   5.0   2.7
 13500  -8.1  17.4  340  48 25   2.8   1.5 |  -5.9  21.4  330  40 20   5.2   2.8
 13000  -7.7  18.1  345  48 25   2.9   1.6 |  -5.2  22.6  330  39 20   3.2   1.8
 12500  -7.3  18.9  345  47 24   2.7   1.5 |  -4.8  23.4  335  39 20   3.5   1.9
 12000  -6.7  19.9  350  47 24   5.8   3.2 |  -4.4  24.1  340  39 20   1.9   1.1
 11500  -5.8  21.6  350  47 24   6.0   3.3 |  -4.1  24.6  345  38 19   1.7   0.9
 11000  -4.9  23.2  350  47 24   7.4   4.1 |  -3.7  25.3  350  37 19   4.6   2.5
 10500  -3.8  25.2  350  46 24   8.2   4.5 |  -3.0  26.6  350  37 19   5.2   2.8
 10250  -3.2  26.2  350  46 23   4.3   2.4 |  -2.7  27.1  350  37 19   2.3   1.2
 10000  -3.1  26.4  350  45 23   4.3   2.4 |  -2.6  27.3  350  37 19   3.6   2.0
  9750  -2.5  27.5  350  43 22   9.1   5.0 |  -2.1  28.2  350  36 19   8.3   4.5
  9500  -1.8  28.8  350  41 21   8.8   4.8 |  -1.5  29.3  355  36 19   7.7   4.2
  9250  -1.2  29.8  345  39 20   6.2   3.4 |  -1.0  30.2  355  35 18   5.6   3.1
  9000  -0.9  30.4  345  37 19   4.6   2.5 |  -0.6  30.9  355  34 17   4.5   2.5
  8750  -0.5  31.1  345  35 18   7.1   3.9 |  -0.2  31.6  355  32 17   6.2   3.4
  8500   0.1  32.2  340  31 16   7.3   4.0 |   0.3  32.5  355  31 16   6.6   3.6
  8250   0.6  33.1  340  29 15   5.9   3.3 |   0.8  33.4  355  28 15   6.2   3.4
  8000   1.0  33.8  335  28 15   5.6   3.1 |   1.2  34.2  355  26 13   6.1   3.3
  7750   1.4  34.5  330  28 14   4.9   2.7 |   1.7  35.1  350  24 12   7.5   4.1
  7500   1.7  35.1  325  28 15   3.2   1.8 |   2.3  36.1  350  21 11   6.5   3.6
  7250   1.9  35.4  320  28 14   2.8   1.5 |   2.7  36.9  340  19 10   4.7   2.6
  7000   2.1  35.8  315  27 14   2.5   1.4 |   3.1  37.6  335  18  9   5.3   2.9
  6750   2.3  36.1  305  27 14   4.4   2.4 |   3.4  38.1  325  17  9   4.6   2.5
  6500   2.7  36.9  305  25 13   5.4   3.0 |   3.8  38.8  320  16  8   4.1   2.2
  6250   3.1  37.6  300  22 11   6.8   3.7 |   4.1  39.4  320  14  7   6.7   3.7
  6000   3.5  38.3  295  19 10  -0.3  -0.2 |   4.5  40.1  315  12  6  -0.9  -0.5
  5750   2.8  37.0  290  15  8 -18.2 -10.0 |   3.8  38.8  310  10  5 -13.7  -7.5
  5500   1.0  33.8  275   9  5 -25.6 -14.0 |   2.6  36.7  300   6  3 -12.6  -6.9

           01/25/2015 at 1400 MST          |       01/25/2015 at 1700 MST
                                           |
K index... +4.8  LI... +9.3                | K index... +5.2  LI... +9.4
CAPE... 0.0  CIN... -0.4                   | CAPE... 0.0  CIN... -0.2
                                           |
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 -59.4 -74.9  340  31 16   4.2   2.3 | -61.8 -79.2  335  32 17   3.3   1.8
 45000 -53.7 -64.7  345  43 22  -8.2  -4.5 | -57.4 -71.3  345  49 25  -5.2  -2.8
 40000 -64.1 -83.4  360  53 27  -6.9  -3.8 | -64.2 -83.6  360  50 26  -4.3  -2.4
 38000 -62.6 -80.7  005  58 30   7.5   4.1 | -62.0 -79.6  010  49 25   7.2   4.0
 36000 -58.1 -72.6  010  62 32   7.5   4.1 | -57.6 -71.7  020  49 25   7.2   4.0
 34000 -53.3 -63.9  015  66 34   9.0   4.9 | -52.8 -63.0  020  48 25   9.2   5.1
 32000 -47.9 -54.2  015  66 34   9.0   4.9 | -47.3 -53.1  010  47 24   9.2   5.1
 30000 -41.8 -43.2  020  63 32   9.0   4.9 | -41.1 -42.0  005  46 24   9.0   4.9
 29000 -39.1 -38.4  020  59 30   9.0   4.9 | -38.4 -37.1  360  45 23   9.0   4.9
 28000 -36.4 -33.5  020  55 28   9.0   4.9 | -35.7 -32.3  355  44 22   9.0   4.9
 27000 -33.7 -28.7  015  52 27   8.8   4.8 | -33.0 -27.4  355  42 22   9.0   4.9
 26000 -31.1 -24.0  015  51 26   8.8   4.9 | -30.3 -22.5  350  41 21   9.0   4.9
 25000 -28.5 -19.3  010  49 25   8.9   4.9 | -27.6 -17.7  345  40 21   9.0   4.9
 24000 -25.9 -14.6  005  47 24   8.1   4.5 | -25.0 -13.0  345  40 21   8.7   4.8
 23000 -23.4 -10.1  355  43 22   8.2   4.5 | -22.4  -8.3  345  42 21   8.7   4.8
 22000 -20.9  -5.6  340  40 21   8.2   4.5 | -19.7  -3.5  345  44 22   8.7   4.8
 21000 -18.4  -1.1  335  42 22   8.6   4.7 | -17.2   1.0  340  41 21   8.5   4.7
 20000 -15.9   3.4  330  46 24   8.6   4.7 | -14.6   5.7  330  36 18   8.5   4.7
 19500 -14.6   5.7  330  48 25   8.6   4.7 | -13.4   7.9  325  33 17   8.5   4.6
 19000 -13.3   8.1  330  50 26   8.9   4.9 | -12.1  10.2  315  31 16   8.3   4.5
 18500 -12.3   9.9  330  51 26   5.2   2.9 | -11.1  12.0  315  31 16   5.1   2.8
 18000 -11.5  11.3  330  50 26   5.5   3.0 | -10.4  13.3  320  31 16   5.4   3.0
 17500 -10.7  12.7  330  49 25   4.5   2.5 |  -9.6  14.7  325  31 16   4.0   2.2
 17000 -10.2  13.6  330  47 24   3.7   2.0 |  -9.1  15.6  330  33 17   3.5   1.9
 16500  -9.6  14.7  330  46 23   3.8   2.1 |  -8.7  16.3  340  34 18   3.7   2.0
 16000  -9.0  15.8  330  44 23   4.9   2.7 |  -8.1  17.4  345  35 18   4.5   2.5
 15500  -8.3  17.1  330  43 22   4.8   2.6 |  -7.4  18.7  345  36 19   4.4   2.4
 15000  -7.2  19.0  330  40 21   5.0   2.7 |  -6.4  20.5  350  36 18   5.2   2.8
 14500  -6.5  20.3  330  39 20   4.9   2.7 |  -5.6  21.9  350  35 18   5.3   2.9
 14000  -5.9  21.4  330  38 19   3.4   1.9 |  -4.8  23.4  350  33 17   5.5   3.0
 13500  -5.4  22.3  330  37 19   3.7   2.0 |  -4.0  24.8  350  32 17   5.5   3.0
 13000  -5.0  23.0  335  36 19   1.8   1.0 |  -3.3  26.1  350  31 16   4.6   2.5
 12500  -4.7  23.5  340  35 18   1.8   1.0 |  -2.6  27.3  350  30 16   4.8   2.6
 12000  -4.4  24.1  340  35 18   3.9   2.1 |  -2.0  28.4  345  29 15   2.9   1.6
 11500  -3.8  25.2  345  34 17   3.5   1.9 |  -1.5  29.3  345  28 15   3.1   1.7
 11000  -3.2  26.2  345  33 17   5.4   3.0 |  -1.0  30.2  345  28 14   4.0   2.2
 10500  -2.4  27.7  345  33 17   5.6   3.1 |  -0.5  31.1  345  28 14   4.1   2.3
 10250  -2.1  28.2  350  33 17   2.4   1.3 |  -0.2  31.6  345  28 14   1.1   0.6
 10000  -1.9  28.6  350  32 17   3.9   2.1 |  -0.2  31.6  345  27 14   3.6   2.0
  9750  -1.4  29.5  345  31 16   8.4   4.6 |   0.4  32.7  340  26 14   8.2   4.5
  9500  -0.8  30.6  345  29 15   7.2   4.0 |   0.9  33.6  340  25 13   6.5   3.6
  9250  -0.4  31.3  345  28 14   5.3   2.9 |   1.3  34.3  340  24 12   4.7   2.6
  9000  -0.0  32.0  345  26 13   4.9   2.7 |   1.6  34.9  340  22 11   4.4   2.4
  8750   0.4  32.7  345  24 12   7.0   3.9 |   2.0  35.6  335  19 10   5.8   3.2
  8500   1.0  33.8  345  21 11   7.6   4.2 |   2.4  36.3  330  16  8   6.4   3.5
  8250   1.5  34.7  340  19 10   7.3   4.0 |   2.9  37.2  325  14  7   6.7   3.7
  8000   2.1  35.8  335  17  9   7.4   4.0 |   3.4  38.1  320  12  6   6.9   3.8
  7750   2.7  36.9  330  15  8   8.4   4.6 |   4.0  39.2  310  11  5   8.8   4.8
  7500   3.3  37.9  325  14  7   6.5   3.5 |   4.6  40.3  300  10  5   7.4   4.1
  7250   3.6  38.5  320  13  7   4.2   2.3 |   5.0  41.0  295  11  6   5.1   2.8
  7000   4.0  39.2  315  12  6   5.0   2.8 |   5.4  41.7  290  13  6   6.0   3.3
  6750   4.3  39.7  310  11  6   4.4   2.4 |   5.8  42.4  290  14  7   4.1   2.2
  6500   4.6  40.3  305   9  5   3.1   1.7 |   6.0  42.8  285  14  7   2.2   1.2
  6250   4.8  40.6  300   7  4   3.5   1.9 |   6.2  43.2  275  13  7   2.9   1.6
  6000   5.0  41.0  290   5  3   0.8   0.4 |   6.4  43.5  265  12  6   1.3   0.7
  5750   4.8  40.6  275   4  2  -2.7  -1.5 |   6.1  43.0  250  11  6  -8.2  -4.5
  5500   4.6  40.3  250   3  2   0.2   0.1 |   4.9  40.8  235   8  4 -19.3 -10.6
________________________________________________________________________________

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.