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
000
UXUS97 KBOU 050130
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1930 MDT Friday, September 4, 2015

This forecast is for Saturday, September 5, 2015:

If the trigger temperature of 77.1 F/25.1 C is reached...then
   Thermal Soaring Index....................... Excellent
   Maximum rate of lift........................ 946 ft/min (4.8 m/s)
   Maximum height of thermals.................. 16075 ft MSL (10768 ft AGL)

Forecast maximum temperature................... 86.0 F/30.5 C
Time of trigger temperature.................... 1030 MDT
Time of overdevelopment........................ 1600 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 11836 ft MSL (6530 ft AGL)
Thermal soaring outlook for Sunday 09/06....... Good

Wave Soaring Index............................. Good
Wave Soaring Index trend (to 1800 MDT)......... No chance
Height of stable layer (12-18K ft MSL)......... 17618 ft MSL (12311 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Weak PVA
Potential height of wave....................... 41010 ft MSL (35703 ft AGL)
Wave soaring outlook for Sunday 09/06.......... Fair

Remarks...

Sunrise/Sunset.................... 06:31:01 / 19:26:07 MDT
Total possible sunshine........... 12 hr 55 min 7 sec (775 min 7 sec)
Altitude of sun at 12:58:07 MDT... 56.95 degrees

Upper air data from numerical model forecast valid on 09/05/2015 at 0600 MDT

Freezing level.................. 14659 ft MSL (9352 ft AGL)
Convective condensation level... 12901 ft MSL (7594 ft AGL)
Lifted condensation level....... 14038 ft MSL (8732 ft AGL)
Lifted index.................... -2.2
K index......................... +29.1

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  -65.6 -86.1   225   57   29   2.4   1.3      M     M       M      M    M
 45000  -60.1 -76.2   235   73   37   6.0   3.3      M     M       M      M    M
 40000  -51.0 -59.8   245   80   41   6.2   3.4      M     M       M      M    M
 38000  -47.3 -53.1   240   73   38   6.2   3.4      M     M       M      M    M
 36000  -43.6 -46.5   235   66   34   6.0   3.3      M     M       M      M    M
 34000  -38.8 -37.8   230   58   30   8.4   4.6      M     M       M      M    M
 32000  -33.1 -27.6   215   51   26   8.2   4.5      M     M       M      M    M
 30000  -28.1 -18.6   210   49   25   8.5   4.7   48.3 119.0    13.9      M    M
 29000  -25.6 -14.1   210   48   24   8.5   4.7   47.9 118.2    13.7      M    M
 28000  -23.1  -9.6   210   46   24   7.0   3.8   47.5 117.5    13.5      M    M
 27000  -21.3  -6.3   215   45   23   5.9   3.2   45.9 114.6    12.4      M    M
 26000  -19.5  -3.1   220   45   23   5.9   3.2   44.4 112.0    11.4      M    M
 25000  -17.7   0.1   225   45   23   5.7   3.1   43.1 109.6    10.5      M    M
 24000  -15.6   3.9   225   42   22   7.5   4.1   42.1 107.7     9.7      M    M
 23000  -13.4   7.9   220   40   20   7.6   4.1   41.2 106.2     9.1      M    M
 22000  -11.3  11.7   210   37   19   8.0   4.4   40.5 104.9     8.5      M    M
 21000   -9.6  14.7   215   34   18   5.0   2.7   39.0 102.2     7.2      M    M
 20000   -8.2  17.2   215   31   16   5.0   2.8   37.3  99.1     5.8      M    M
 19500   -7.5  18.5   220   29   15   5.1   2.8   36.5  97.7     5.1      M    M
 19000   -6.7  19.9   220   27   14   6.4   3.5   35.8  96.4     4.5      M    M
 18500   -5.7  21.7   220   24   12   7.3   4.0   35.3  95.6     4.0      M    M
 18000   -4.7  23.5   220   20   10   7.8   4.3   34.9  94.8     3.6      M    M
 17500   -4.0  24.8   220   17    9   3.0   1.6   34.1  93.5     2.9      M    M
 17000   -3.3  26.1   220   13    7   3.5   1.9   32.5  90.6     1.4      M    M
 16500   -2.7  27.1   225   11    6   4.6   2.5   31.6  88.9     0.5      M    M
 16000   -2.0  28.4   235    9    5   4.5   2.4   30.7  87.3    -0.3    933  4.7
 15500   -1.3  29.7   245    8    4   5.7   3.1   29.9  85.8    -1.0    897  4.6
 15000   -0.5  31.1   255    7    4   6.1   3.3   29.3  84.7    -1.6    856  4.3
 14500    0.4  32.7   265    6    3   7.5   4.1   28.7  83.6    -2.2    815  4.1
 14000    1.8  35.2   275    5    3   9.3   5.1   28.6  83.4    -2.3    759  3.9
 13500    3.2  37.8   295    5    2   9.2   5.0   28.5  83.3    -2.4    702  3.6
 13000    4.5  40.1   310    5    3   8.7   4.8   28.3  83.0    -2.5    648  3.3
 12500    5.8  42.4   315    7    3   8.7   4.8   28.2  82.7    -2.7    595  3.0
 12000    7.0  44.6   320    8    4   8.5   4.7   28.0  82.4    -2.9    542  2.8
 11500    8.3  46.9   320    8    4   8.6   4.7   27.8  82.0    -3.2    491  2.5
 11000    9.4  48.9   315    9    4   7.2   4.0   27.5  81.5    -3.5    442  2.2
 10500   10.5  50.9   310    9    5   5.2   2.9   27.2  80.9    -3.9    394  2.0
 10250   10.8  51.4   310   10    5   5.6   3.1   26.7  80.1    -4.3    378  1.9
 10000   11.4  52.5   310   10    5   9.5   5.2   26.6  79.9    -4.5    353  1.8
  9750   12.1  53.8   310   10    5   9.1   5.0   26.5  79.8    -4.6    326  1.7
  9500   12.7  54.9   305   10    5   9.3   5.1   26.5  79.7    -4.7    299  1.5
  9250   13.3  55.9   305   10    5   7.0   3.8   26.4  79.6    -4.8    273  1.4
  9000   13.7  56.7   305    9    5   6.4   3.5   26.1  79.0    -5.1    253  1.3
  8750   14.3  57.7   305    9    4   7.7   4.2   25.9  78.7    -5.3    230  1.2
  8500   14.8  58.6   305    8    4   7.3   4.0   25.8  78.4    -5.5    206  1.0
  8250   15.3  59.5   300    7    4   7.5   4.1   25.6  78.1    -5.7    183  0.9
  8000   15.8  60.4   295    6    3   6.7   3.7   25.4  77.7    -6.0    161  0.8
  7750   16.3  61.3   290    5    3   5.8   3.2   25.1  77.2    -6.3    140  0.7
  7500   16.7  62.1   285    5    2   5.4   2.9   24.8  76.6    -6.6    121  0.6
  7250   17.0  62.6   275    4    2   4.8   2.6   24.4  76.0    -7.0    103  0.5
  7000   17.3  63.1   265    4    2   4.5   2.5   24.0  75.3    -7.5     86  0.4
  6750   17.6  63.7   250    3    2   4.1   2.3   23.6  74.5    -7.9     70  0.4
  6500   17.9  64.2   235    3    2   3.2   1.7   23.2  73.7    -8.4     55  0.3
  6250   18.0  64.4   225    3    2   2.6   1.5   22.6  72.8    -9.0     43  0.2
  6000   18.2  64.8   215    3    2   2.7   1.5   22.1  71.8    -9.6     30  0.2
  5750   18.3  64.9   205    3    2   2.6   1.4   21.6  70.8   -10.2     19  0.1
  5500   18.5  65.3   200    3    1   3.8   2.1   21.1  69.9   -10.8      7  0.0

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

           09/05/2015 at 0900 MDT          |       09/05/2015 at 1200 MDT
                                           |
K index... +25.7  LI... -1.3               | K index... +25.6  LI... -1.3
CAPE... +56.5  CIN... -87.6                | CAPE... +80.0  CIN... -41.6
                                           |
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 -65.9 -86.6  220  55 28   1.9   1.0 | -65.3 -85.5  220  57 29   1.7   0.9
 45000 -60.7 -77.3  230  73 38   6.5   3.5 | -60.6 -77.1  230  74 38   6.0   3.3
 40000 -50.9 -59.6  235  77 40   6.7   3.7 | -51.5 -60.7  230  81 42   6.9   3.8
 38000 -46.9 -52.4  235  76 39   6.7   3.7 | -47.3 -53.1  230  81 42   6.9   3.8
 36000 -42.8 -45.0  230  76 39   6.6   3.6 | -43.2 -45.8  225  81 42   6.8   3.7
 34000 -38.2 -36.8  230  72 37   7.9   4.3 | -38.4 -37.1  225  73 38   8.3   4.5
 32000 -32.9 -27.2  225  66 34   7.7   4.2 | -32.8 -27.0  225  64 33   8.3   4.6
 30000 -28.4 -19.1  225  60 31   7.5   4.1 | -29.0 -20.2  225  56 29   6.0   3.3
 29000 -26.1 -15.0  225  57 29   7.5   4.1 | -27.2 -17.0  225  53 27   6.0   3.3
 28000 -23.9 -11.0  225  54 28   6.8   3.8 | -25.3 -13.5  225  49 25   6.9   3.8
 27000 -22.0  -7.6  225  50 26   6.4   3.5 | -23.0  -9.4  225  47 24   7.6   4.2
 26000 -20.1  -4.2  220  47 24   6.4   3.5 | -20.8  -5.4  225  44 23   7.6   4.2
 25000 -18.2  -0.8  220  44 22   6.3   3.5 | -18.5  -1.3  225  41 21   7.7   4.2
 24000 -16.2   2.8  220  41 21   6.8   3.7 | -16.4   2.5  225  39 20   6.5   3.6
 23000 -14.2   6.4  215  38 19   6.8   3.8 | -14.5   5.9  225  38 19   6.6   3.6
 22000 -12.1  10.2  215  35 18   7.1   3.9 | -12.5   9.5  225  36 19   6.6   3.6
 21000 -10.6  12.9  215  32 17   5.1   2.8 | -10.9  12.4  230  35 18   5.5   3.0
 20000  -9.1  15.6  225  30 16   5.2   2.9 |  -9.3  15.3  230  33 17   5.6   3.1
 19500  -8.4  16.9  225  30 15   5.3   2.9 |  -8.5  16.7  235  33 17   5.7   3.1
 19000  -7.7  18.1  230  29 15   6.4   3.5 |  -7.7  18.1  235  32 16   5.6   3.1
 18500  -6.7  19.9  230  27 14   6.9   3.8 |  -6.9  19.6  235  31 16   5.7   3.1
 18000  -5.7  21.7  230  25 13   7.0   3.8 |  -6.2  20.8  235  29 15   6.0   3.3
 17500  -4.8  23.4  230  23 12   5.9   3.3 |  -5.3  22.5  235  28 14   6.7   3.7
 17000  -4.0  24.8  230  21 11   6.1   3.3 |  -3.9  25.0  235  26 14   6.7   3.7
 16500  -2.7  27.1  230  18  9   6.4   3.5 |  -2.9  26.8  235  25 13   7.2   3.9
 16000  -1.7  28.9  230  16  8   6.5   3.6 |  -1.9  28.6  235  23 12   7.2   4.0
 15500  -0.9  30.4  230  14  7   5.0   2.7 |  -0.9  30.4  235  21 11   6.5   3.6
 15000  -0.2  31.6  230  12  6   4.9   2.7 |   0.1  32.2  235  20 11   6.5   3.5
 14500   0.5  32.9  235  10  5   6.4   3.5 |   1.0  33.8  235  19 10   7.3   4.0
 14000   1.7  35.1  235   8  4   7.8   4.3 |   2.2  36.0  230  17  9   7.9   4.3
 13500   2.9  37.2  240   6  3   7.9   4.4 |   3.4  38.1  230  15  8   7.7   4.2
 13000   4.1  39.4  250   5  3   8.0   4.4 |   4.4  39.9  225  14  7   7.2   4.0
 12500   5.3  41.5  270   5  2   8.0   4.4 |   5.5  41.9  225  12  6   7.4   4.1
 12000   6.5  43.7  290   5  3   8.4   4.6 |   6.7  44.1  225  10  5   8.6   4.7
 11500   7.8  46.0  305   6  3   8.4   4.6 |   8.0  46.4  235   8  4   8.5   4.7
 11000   9.1  48.4  310   7  4   8.5   4.7 |   9.2  48.6  240   6  3   8.1   4.4
 10500  10.3  50.5  315   9  5   5.1   2.8 |  10.5  50.9  250   5  2   4.9   2.7
 10250  10.6  51.1  315  10  5   5.2   2.9 |  10.7  51.3  255   4  2   5.8   3.2
 10000  11.2  52.2  315  11  6  10.4   5.7 |  11.4  52.5  265   4  2  10.8   5.9
  9750  11.9  53.4  315  12  6   9.7   5.3 |  12.1  53.8  275   4  2   9.6   5.3
  9500  12.6  54.7  315  13  7   9.6   5.3 |  12.9  55.2  290   5  2   9.4   5.2
  9250  13.3  55.9  315  14  7   7.7   4.2 |  13.5  56.3  295   5  3   7.6   4.2
  9000  13.8  56.8  310  15  8   7.9   4.3 |  14.0  57.2  300   5  3   8.0   4.4
  8750  14.4  57.9  310  15  8   9.2   5.1 |  14.6  58.3  305   5  3   8.9   4.9
  8500  15.1  59.2  310  16  8   8.6   4.7 |  15.3  59.5  310   5  3   8.7   4.8
  8250  15.7  60.3  310  16  8   8.1   4.5 |  15.9  60.6  310   5  3   8.6   4.7
  8000  16.3  61.3  315  16  8   7.3   4.0 |  16.4  61.5  310   5  2   9.5   5.2
  7750  16.7  62.1  315  15  8   6.7   3.7 |  17.2  63.0  310   5  2  10.7   5.9
  7500  17.2  63.0  315  15  8   6.1   3.4 |  17.9  64.2  310   4  2  10.3   5.7
  7250  17.6  63.7  315  13  7   5.5   3.0 |  18.6  65.5  310   4  2   9.9   5.4
  7000  17.9  64.2  315  12  6   5.3   2.9 |  19.4  66.9  310   4  2   9.8   5.4
  6750  18.3  64.9  315  10  5   4.6   2.5 |  20.1  68.2  310   4  2   9.4   5.1
  6500  18.5  65.3  315   8  4   3.9   2.1 |  20.8  69.4  310   4  2  10.4   5.7
  6250  18.7  65.7  310   6  3   3.9   2.2 |  21.6  70.9  305   4  2  11.7   6.4
  6000  18.9  66.0  300   4  2   3.5   1.9 |  22.5  72.5  305   4  2  10.1   5.6
  5750  19.1  66.4  265   2  1   5.3   2.9 |  23.3  73.9  305   4  2  13.4   7.4
  5500  19.6  67.3  240   2  1  11.0   6.0 |  24.7  76.5  305   4  2  24.5  13.5

           09/05/2015 at 1500 MDT          |       09/05/2015 at 1800 MDT
                                           |
K index... +26.9  LI... -1.5               | K index... +33.0  LI... -3.2
CAPE... +130.2  CIN... -22.9               | CAPE... +365.8  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 -65.2 -85.4  225  61 32   1.5   0.8 | -65.5 -85.9  225  65 33   2.3   1.2
 45000 -60.7 -77.3  230  81 41   6.1   3.3 | -60.5 -76.9  230  83 43   5.4   2.9
 40000 -51.4 -60.5  230  86 44   7.0   3.8 | -52.1 -61.8  230  87 45   7.4   4.1
 38000 -47.2 -53.0  230  83 43   7.0   3.8 | -47.6 -53.7  230  84 43   7.5   4.1
 36000 -43.0 -45.4  230  81 42   6.9   3.8 | -43.1 -45.6  230  81 42   7.4   4.1
 34000 -38.3 -36.9  230  74 38   8.0   4.4 | -38.4 -37.1  230  77 40   8.0   4.4
 32000 -32.8 -27.0  225  64 33   8.1   4.4 | -33.0 -27.4  235  73 38   8.0   4.4
 30000 -29.2 -20.6  230  58 30   5.8   3.2 | -28.7 -19.7  235  67 34   7.1   3.9
 29000 -27.4 -17.3  230  56 29   5.8   3.2 | -26.6 -15.9  235  63 33   7.1   3.9
 28000 -25.6 -14.1  235  53 27   7.3   4.0 | -24.4 -11.9  235  60 31   6.8   3.7
 27000 -23.2  -9.8  235  49 25   8.1   4.5 | -22.5  -8.5  235  56 29   6.7   3.7
 26000 -20.7  -5.3  230  45 23   8.1   4.5 | -20.5  -4.9  235  52 27   6.7   3.7
 25000 -18.3  -0.9  230  42 21   8.3   4.5 | -18.6  -1.5  235  48 25   6.8   3.7
 24000 -16.2   2.8  230  40 20   6.3   3.5 | -16.7   1.9  235  44 22   6.4   3.5
 23000 -14.3   6.3  230  38 20   6.4   3.5 | -14.8   5.4  235  39 20   6.4   3.5
 22000 -12.4   9.7  230  37 19   6.4   3.5 | -12.9   8.8  235  34 18   6.4   3.5
 21000 -10.7  12.7  235  35 18   5.5   3.0 | -11.2  11.8  240  32 16   5.9   3.3
 20000  -9.1  15.6  235  34 18   5.5   3.0 |  -9.4  15.1  240  29 15   6.0   3.3
 19500  -8.2  17.2  235  33 17   5.6   3.1 |  -8.6  16.5  245  28 15   6.0   3.3
 19000  -7.4  18.7  240  33 17   5.6   3.1 |  -7.7  18.1  245  27 14   6.5   3.6
 18500  -6.6  20.1  240  32 16   5.8   3.2 |  -6.7  19.9  240  25 13   6.7   3.7
 18000  -5.8  21.6  240  31 16   6.1   3.4 |  -5.8  21.6  235  24 12   6.7   3.7
 17500  -4.9  23.2  240  29 15   6.8   3.8 |  -4.8  23.4  230  23 12   6.4   3.5
 17000  -4.0  24.8  240  28 15   7.0   3.8 |  -3.9  25.0  225  22 11   6.4   3.5
 16500  -2.5  27.5  240  27 14   7.8   4.3 |  -2.5  27.5  215  21 11   6.7   3.7
 16000  -1.4  29.5  235  26 13   7.9   4.3 |  -1.6  29.1  205  20 10   6.7   3.7
 15500  -0.3  31.5  235  25 13   8.1   4.4 |  -0.6  30.9  195  19 10   7.5   4.1
 15000   0.9  33.6  235  24 12   8.1   4.5 |   0.5  32.9  190  17  9   7.6   4.2
 14500   2.0  35.6  230  23 12   8.1   4.4 |   1.5  34.7  180  16  8   8.2   4.5
 14000   3.2  37.8  230  21 11   8.1   4.4 |   2.8  37.0  175  15  8   8.6   4.7
 13500   4.3  39.7  225  20 10   8.3   4.6 |   4.0  39.2  170  13  7   9.4   5.2
 13000   5.6  42.1  220  18  9   8.9   4.9 |   5.5  41.9  165  12  6  10.8   5.9
 12500   6.9  44.4  215  16  8   8.7   4.8 |   7.1  44.8  160  12  6  10.7   5.9
 12000   8.1  46.6  210  14  7   8.0   4.4 |   8.6  47.5  160  11  6  10.0   5.5
 11500   9.3  48.7  200  12  6   8.1   4.4 |  10.1  50.2  160  10  5   9.9   5.5
 11000  10.4  50.7  195  10  5   7.5   4.1 |  11.4  52.5  160   9  5   8.1   4.4
 10500  11.5  52.7  185   8  4   4.4   2.4 |  12.5  54.5  155   8  4  11.1   6.1
 10250  11.7  53.1  185   7  4   6.4   3.5 |  13.5  56.3  155   7  4  11.6   6.4
 10000  12.5  54.5  185   7  3  12.0   6.6 |  14.2  57.6  155   6  3   8.1   4.4
  9750  13.3  55.9  180   6  3  10.7   5.9 |  14.9  58.8  155   5  3   9.1   5.0
  9500  14.1  57.4  180   6  3  10.5   5.7 |  15.5  59.9  150   4  2   8.7   4.8
  9250  14.8  58.6  180   6  3   8.7   4.8 |  16.2  61.2  150   3  2   8.9   4.9
  9000  15.5  59.9  180   5  3   9.4   5.2 |  16.8  62.2  150   3  1   9.5   5.2
  8750  16.2  61.2  180   5  3  10.6   5.8 |  17.6  63.7  150   2  1   9.7   5.3
  8500  17.0  62.6  180   5  3  10.3   5.6 |  18.3  64.9  140   1  1   9.7   5.3
  8250  17.8  64.0  180   5  3  10.5   5.8 |  19.0  66.2  000   0  0  10.4   5.7
  8000  18.6  65.5  180   5  2  10.2   5.6 |  19.8  67.6  345   1  0   9.9   5.4
  7750  19.3  66.7  180   5  2   9.8   5.4 |  20.5  68.9  340   1  1   9.0   4.9
  7500  20.0  68.0  180   5  2  10.1   5.5 |  21.2  70.2  335   2  1   9.5   5.2
  7250  20.8  69.4  180   5  2  10.5   5.8 |  21.9  71.4  335   2  1  10.1   5.6
  7000  21.6  70.9  180   4  2  10.2   5.6 |  22.7  72.9  335   3  1  10.1   5.5
  6750  22.3  72.1  185   4  2   8.8   4.8 |  23.4  74.1  335   3  1   9.6   5.3
  6500  23.0  73.4  185   4  2   9.9   5.4 |  24.1  75.4  335   3  2  10.0   5.5
  6250  23.8  74.8  185   4  2  11.7   6.4 |  24.9  76.8  335   3  2  10.8   5.9
  6000  24.6  76.3  185   4  2  10.4   5.7 |  25.7  78.3  330   4  2  10.3   5.7
  5750  25.4  77.7  185   4  2  13.1   7.2 |  26.5  79.7  330   4  2  10.7   5.9
  5500  26.7  80.1  190   4  2  23.0  12.6 |  27.3  81.1  330   4  2  13.4   7.4
________________________________________________________________________________

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.