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
000
UXUS97 KBOU 221333
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0733 MDT Friday, August 22, 2014

This forecast is for Friday, August 22, 2014:

If the trigger temperature of 75.1 F/23.9 C is reached...then
   Thermal Soaring Index....................... Fair
   Maximum rate of lift........................ 276 ft/min (1.4 m/s)
   Maximum height of thermals.................. 11606 ft MSL (6321 ft AGL)

Forecast maximum temperature................... 80.0 F/27.1 C
Time of trigger temperature.................... 1200 MDT
Time of overdevelopment........................ 1400 MDT
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 9138 ft MSL (3852 ft AGL)
Thermal soaring outlook for Saturday 08/23..... Fair

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 PVA
Potential height of wave....................... 24762 ft MSL (19477 ft AGL)
Wave soaring outlook for Saturday 08/23........ Poor

Remarks... Showers and thunderstorms

Sunrise/Sunset.................... 06:18:08 / 19:47:05 MDT
Total possible sunshine........... 13 hr 28 min 56 sec (808 min 56 sec)
Altitude of sun at 13:02:13 MDT... 61.83 degrees

Upper air data from rawinsonde observation taken on 08/22/2014 at 0600 MDT

Freezing level.................. 15612 ft MSL (10327 ft AGL)
Convective condensation level... 13043 ft MSL (7758 ft AGL)
Lifted condensation level....... 12547 ft MSL (7262 ft AGL)
Lifted index.................... -1.7
K index......................... +27.3

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  -65.5 -85.9   225   29   15  -8.4  -4.6   83.4 182.1    33.1      M    M
 45000  -62.8 -81.0   215   72   37   1.6   0.9   63.6 146.5    23.1      M    M
 40000  -53.4 -64.1   215   78   40   7.5   4.1   55.4 131.7    19.2      M    M
 38000  -48.9 -56.0   215   73   38   5.9   3.2   53.4 128.2    18.4      M    M
 36000  -43.7 -46.7   215   69   35   9.0   5.0   52.5 126.5    18.2      M    M
 34000  -38.2 -36.8   215   67   35   8.0   4.4   51.0 123.8    17.6      M    M
 32000  -34.4 -29.9   215   54   28  10.1   5.6   48.2 118.8    16.0      M    M
 30000  -29.7 -21.5   215   42   22   7.5   4.1   46.8 116.2    15.2      M    M
 29000  -27.5 -17.5   220   40   20   7.2   3.9   45.8 114.5    14.7      M    M
 28000  -25.4 -13.7   225   38   19   7.2   4.0   44.9 112.8    14.1      M    M
 27000  -23.2  -9.8   220   34   18   7.3   4.0   43.9 111.0    13.4      M    M
 26000  -21.1  -6.0   215   31   16   7.4   4.1   43.0 109.4    12.8      M    M
 25000  -18.9  -2.0   220   34   17   7.4   4.1   42.1 107.9    12.2      M    M
 24000  -16.7   1.9   225   35   18   7.0   3.9   41.3 106.3    11.6      M    M
 23000  -14.9   5.2   220   32   17   5.9   3.3   39.9 103.8    10.6      M    M
 22000  -13.2   8.2   210   30   15   6.0   3.3   38.6 101.4     9.5      M    M
 21000  -11.5  11.3   215   30   16   5.8   3.2   37.2  98.9     8.4      M    M
 20000   -9.8  14.4   220   31   16   6.4   3.5   35.7  96.3     7.3      M    M
 19500   -8.4  16.9   215   30   15  12.3   6.7   35.8  96.4     7.2      M    M
 19000   -7.1  19.2   215   29   15   4.7   2.6   35.6  96.1     7.0      M    M
 18500   -6.6  20.1   215   29   15   4.0   2.2   34.6  94.2     6.2      M    M
 18000   -6.0  21.2   210   29   15   5.0   2.7   33.5  92.4     5.3      M    M
 17500   -4.9  23.2   210   29   15   8.7   4.8   33.1  91.7     5.0      M    M
 17000   -3.6  25.5   210   30   15   8.5   4.7   32.9  91.3     4.8      M    M
 16500   -1.7  28.9   205   30   15   8.5   4.6   32.6  90.7     4.5      M    M
 16000   -0.5  31.1   205   30   15   7.5   4.1   32.5  90.4     4.4      M    M
 15500    0.3  32.5   205   28   15   6.9   3.8   31.9  89.4     3.7      M    M
 15000    1.4  34.5   200   27   14   5.8   3.2   31.5  88.7     3.4      M    M
 14500    2.1  35.8   200   26   13   6.4   3.5   30.8  87.4     2.6      M    M
 14000    2.9  37.2   200   25   13   6.7   3.7   30.2  86.3     2.0      M    M
 13500    4.0  39.2   195   24   12   7.7   4.2   29.8  85.6     1.6      M    M
 13000    5.1  41.2   190   22   11   7.9   4.3   29.5  85.0     1.2      M    M
 12500    6.1  43.0   195   18    9   6.2   3.4   29.0  84.3     0.8      M    M
 12000    7.1  44.8   205   14    7   6.0   3.3   28.5  83.2     0.3      M    M
 11500    8.1  46.6   195   12    6   6.0   3.3   27.9  82.1    -0.2    462  2.3
 11000    9.0  48.2   185    9    5   6.1   3.3   27.3  81.1    -0.6    418  2.1
 10500   10.0  50.0   285    1    0   6.2   3.4   26.7  80.0    -1.1    374  1.9
 10250   10.5  50.9   320    2    1   7.0   3.8   26.4  79.6    -1.3    352  1.8
 10000   11.0  51.8   295    2    1   7.0   3.9   26.2  79.2    -1.6    329  1.7
  9750   11.5  52.7   340    2    1   7.5   4.1   26.0  78.8    -1.8    307  1.6
  9500   12.0  53.6   010    3    1   4.9   2.7   25.8  78.4    -2.1    285  1.4
  9250   12.0  53.6   025    4    2   1.8   1.0   25.2  77.4    -2.8    277  1.4
  9000   12.1  53.8   030    5    3   2.3   1.2   24.7  76.4    -3.4    266  1.4
  8750   12.3  54.1   035    4    2   1.6   0.9   24.1  75.3    -4.0    255  1.3
  8500   12.4  54.3   040    3    2   3.9   2.1   23.5  74.2    -4.6    244  1.2
  8250   12.8  55.0   050    3    1   6.8   3.7   23.2  73.7    -4.9    224  1.1
  8000   13.3  55.9   065    2    1   6.8   3.7   22.9  73.3    -5.2    201  1.0
  7750   13.8  56.8   080    2    1   6.8   3.7   22.7  72.9    -5.4    179  0.9
  7500   14.3  57.7   090    2    1   6.8   3.7   22.5  72.5    -5.7    156  0.8
  7250   14.8  58.6   100    3    1   6.8   3.7   22.3  72.1    -5.9    134  0.7
  7000   15.3  59.5   105    3    2   6.8   3.7   22.0  71.7    -6.1    111  0.6
  6750   15.8  60.4   125    2    1   6.8   3.7   21.8  71.3    -6.4     89  0.5
  6500   16.3  61.3   160    2    1   6.7   3.6   21.6  70.8    -6.6     66  0.3
  6250   16.8  62.2   200    2    1   7.2   4.0   21.4  70.4    -6.9     44  0.2
  6000   17.3  63.1   220    3    1   5.1   2.8   21.1  70.0    -7.1     21  0.1
  5750   17.5  63.5   215    2    1   2.5   1.4   20.6  69.1    -7.7     10  0.1
  5500   17.5  63.5   205    2    1   3.2   1.8   20.1  68.2    -8.4      1  0.0

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

           08/22/2014 at 0900 MDT          |       08/22/2014 at 1200 MDT
                                           |
K index... +28.9  LI... -2.5               | K index... +27.9  LI... -2.6
CAPE... +390.4  CIN... -5.1                | CAPE... +294.5  CIN... -17.7
                                           |
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 -64.3 -83.7  225  40 21   0.6   0.3 | -64.4 -83.9  220  39 20   1.0   0.5
 45000 -61.2 -78.2  220  62 32   5.4   3.0 | -61.0 -77.8  215  60 31   5.0   2.8
 40000 -52.8 -63.0  220  71 36   7.0   3.8 | -53.1 -63.6  215  69 35   7.1   3.9
 38000 -48.5 -55.3  220  69 36   7.0   3.8 | -48.8 -55.8  220  68 35   7.2   3.9
 36000 -44.3 -47.7  220  68 35   6.9   3.8 | -44.5 -48.1  220  68 35   7.1   3.9
 34000 -39.0 -38.2  220  61 31   7.9   4.4 | -38.9 -38.0  220  61 31   8.4   4.6
 32000 -34.3 -29.7  215  53 27   7.8   4.3 | -33.8 -28.8  220  54 28   9.2   5.0
 30000 -29.8 -21.6  210  45 23   7.5   4.1 | -29.0 -20.2  220  46 24   8.1   4.5
 29000 -27.5 -17.5  210  41 21   7.5   4.1 | -26.6 -15.9  220  42 22   8.1   4.5
 28000 -25.3 -13.5  210  38 19   7.4   4.0 | -24.2 -11.6  220  39 20   7.2   4.0
 27000 -23.1  -9.6  210  35 18   7.3   4.0 | -22.1  -7.8  220  38 19   6.9   3.8
 26000 -21.0  -5.8  215  33 17   7.4   4.0 | -20.1  -4.2  220  36 19   7.0   3.8
 25000 -18.8  -1.8  220  31 16   7.3   4.0 | -18.0  -0.4  220  35 18   6.9   3.8
 24000 -16.8   1.8  225  30 16   6.8   3.7 | -16.1   3.0  215  34 18   6.3   3.5
 23000 -14.8   5.4  225  30 15   6.8   3.7 | -14.3   6.3  215  33 17   6.4   3.5
 22000 -12.8   9.0  230  30 15   6.7   3.7 | -12.4   9.7  215  32 16   6.3   3.5
 21000 -10.9  12.4  225  32 16   6.4   3.5 | -10.7  12.7  215  31 16   5.8   3.2
 20000  -9.1  15.6  225  34 17   6.4   3.5 |  -9.0  15.8  210  30 15   5.8   3.2
 19500  -8.1  17.4  220  35 18   6.5   3.6 |  -8.2  17.2  210  29 15   5.8   3.2
 19000  -7.3  18.9  220  36 18   5.7   3.2 |  -7.3  18.9  210  29 15   5.9   3.2
 18500  -6.4  20.5  215  36 19   5.7   3.1 |  -6.5  20.3  205  30 15   5.9   3.2
 18000  -5.6  21.9  215  36 19   5.7   3.2 |  -5.6  21.9  205  30 16   5.9   3.2
 17500  -4.7  23.5  215  36 18   6.0   3.3 |  -4.8  23.4  205  31 16   5.8   3.2
 17000  -3.9  25.0  210  35 18   5.9   3.2 |  -3.9  25.0  205  31 16   5.7   3.1
 16500  -2.3  27.9  210  33 17   7.5   4.1 |  -2.4  27.7  205  31 16   7.6   4.2
 16000  -1.2  29.8  210  31 16   7.4   4.1 |  -1.3  29.7  210  30 15   7.5   4.1
 15500  -0.1  31.8  210  29 15   8.3   4.6 |  -0.1  31.8  210  29 15   8.4   4.6
 15000   1.1  34.0  210  26 14   8.3   4.6 |   1.2  34.2  215  28 14   8.3   4.6
 14500   2.2  36.0  210  24 12   6.9   3.8 |   2.4  36.3  220  27 14   8.1   4.4
 14000   3.1  37.6  205  22 11   6.5   3.6 |   3.5  38.3  220  26 13   8.0   4.4
 13500   4.0  39.2  200  21 11   6.1   3.4 |   4.7  40.5  220  24 12   7.0   3.8
 13000   4.7  40.5  190  20 10   5.8   3.2 |   5.5  41.9  215  21 11   5.9   3.2
 12500   5.5  41.9  175  20 10   6.2   3.4 |   6.3  43.3  210  18  9   4.9   2.7
 12000   6.4  43.5  165  20 10   6.9   3.8 |   6.6  43.9  200  16  8   2.6   1.5
 11500   7.4  45.3  155  20 10   6.5   3.6 |   6.8  44.2  190  14  7   4.1   2.3
 11000   8.2  46.8  155  18  9   5.0   2.8 |   7.8  46.0  175  14  7   8.9   4.9
 10500   8.9  48.0  150  15  8   3.6   2.0 |   9.0  48.2  160  14  7   6.2   3.4
 10250   9.1  48.4  150  14  7   3.0   1.6 |   9.3  48.7  160  13  7   2.6   1.4
 10000   9.5  49.1  145  12  6   5.5   3.0 |   9.6  49.3  155  12  6   4.2   2.3
  9750   9.9  49.8  145  10  5   5.9   3.2 |   9.9  49.8  155  10  5   4.7   2.6
  9500  10.4  50.7  140   8  4   5.6   3.1 |  10.2  50.4  155   8  4   4.0   2.2
  9250  10.8  51.4  135   6  3   5.1   2.8 |  10.5  50.9  150   6  3   3.0   1.7
  9000  11.2  52.2  130   5  3   6.3   3.4 |  10.8  51.4  145   4  2   4.2   2.3
  8750  11.7  53.1  115   3  2   7.5   4.1 |  11.1  52.0  110   2  1   4.8   2.6
  8500  12.2  54.0  085   2  1   6.5   3.6 |  11.5  52.7  040   2  1   5.8   3.2
  8250  12.6  54.7  055   2  1   5.6   3.1 |  12.0  53.6  020   4  2   7.0   3.8
  8000  13.0  55.4  025   3  1   6.1   3.3 |  12.4  54.3  010   6  3   7.9   4.3
  7750  13.5  56.3  010   3  2   6.6   3.6 |  13.1  55.6  010   7  4   9.7   5.3
  7500  13.9  57.0  360   4  2   5.8   3.2 |  13.8  56.8  010   8  4   9.8   5.4
  7250  14.3  57.7  360   5  3   5.3   2.9 |  14.5  58.1  010   8  4   9.7   5.3
  7000  14.7  58.5  360   7  3   5.1   2.8 |  15.3  59.5  010   8  4   9.7   5.3
  6750  15.1  59.2  360   8  4   5.0   2.8 |  16.0  60.8  010   8  4  10.3   5.7
  6500  15.5  59.9  360   8  4   6.1   3.4 |  16.8  62.2  005   8  4  10.8   5.9
  6250  15.9  60.6  360   7  4   6.2   3.4 |  17.6  63.7  005   8  4  11.4   6.2
  6000  16.3  61.3  005   6  3   7.1   3.9 |  18.4  65.1  005   8  4   9.2   5.1
  5750  16.9  62.4  005   6  3  11.1   6.1 |  19.2  66.6  005   8  4  13.5   7.4
  5500  17.9  64.2  005   6  3  14.7   8.1 |  20.6  69.1  005   8  4  26.7  14.7

           08/22/2014 at 1500 MDT          |       08/22/2014 at 1800 MDT
                                           |
K index... +26.1  LI... -2.1               | K index... +28.6  LI... -1.6
CAPE... +241.2  CIN... -10.3               | CAPE... +178.4  CIN... -12.1
                                           |
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 -65.1 -85.2  215  37 19   1.0   0.5 | -64.8 -84.6  210  38 20   0.4   0.2
 45000 -61.4 -78.5  210  60 31   5.7   3.1 | -62.0 -79.6  215  60 31   5.1   2.8
 40000 -52.6 -62.7  205  69 35   7.3   4.0 | -53.5 -64.3  210  58 30   9.0   4.9
 38000 -48.1 -54.6  210  66 34   7.4   4.1 | -48.1 -54.6  210  55 28   9.0   5.0
 36000 -43.7 -46.7  210  63 32   7.2   4.0 | -42.7 -44.9  210  51 26   9.1   5.0
 34000 -37.9 -36.2  210  55 29   8.7   4.8 | -36.7 -34.1  205  48 25   8.8   4.8
 32000 -32.7 -26.9  205  49 25   9.5   5.2 | -31.4 -24.5  200  46 24   9.8   5.4
 30000 -27.9 -18.2  200  45 23   8.0   4.4 | -26.8 -16.2  195  44 23   7.7   4.2
 29000 -25.6 -14.1  205  44 22   8.0   4.4 | -24.5 -12.1  195  44 22   7.7   4.2
 28000 -23.2  -9.8  205  42 22   7.1   3.9 | -22.2  -8.0  195  43 22   7.1   3.9
 27000 -21.2  -6.2  205  39 20   6.8   3.7 | -20.2  -4.4  195  43 22   6.9   3.8
 26000 -19.2  -2.6  205  37 19   6.8   3.7 | -18.2  -0.8  195  43 22   7.0   3.8
 25000 -17.2   1.0  205  35 18   6.8   3.8 | -16.1   3.0  195  43 22   7.0   3.8
 24000 -15.3   4.5  205  33 17   6.6   3.6 | -14.2   6.4  195  42 21   6.2   3.4
 23000 -13.3   8.1  205  32 17   6.7   3.6 | -12.4   9.7  195  41 21   6.3   3.4
 22000 -11.4  11.5  205  31 16   6.6   3.6 | -10.6  12.9  190  40 20   6.3   3.5
 21000  -9.7  14.5  205  31 16   5.5   3.0 |  -8.9  16.0  190  38 20   5.6   3.1
 20000  -8.1  17.4  210  30 16   5.6   3.1 |  -7.3  18.9  190  36 19   5.6   3.1
 19500  -7.3  18.9  210  30 15   5.6   3.1 |  -6.5  20.3  190  35 18   5.6   3.1
 19000  -6.5  20.3  210  29 15   4.8   2.6 |  -5.7  21.7  190  34 18   5.5   3.0
 18500  -5.9  21.4  210  29 15   4.6   2.5 |  -4.9  23.2  185  33 17   5.5   3.0
 18000  -5.2  22.6  210  28 14   4.6   2.5 |  -4.1  24.6  185  33 17   5.6   3.0
 17500  -4.5  23.9  210  26 14   5.3   2.9 |  -3.4  25.9  185  32 16   4.7   2.6
 17000  -3.3  26.1  215  24 12   5.4   3.0 |  -2.7  27.1  180  31 16   4.8   2.6
 16500  -2.4  27.7  220  23 12   6.2   3.4 |  -1.8  28.8  180  29 15   3.8   2.1
 16000  -1.5  29.3  220  22 11   6.0   3.3 |  -1.2  29.8  175  27 14   3.8   2.1
 15500  -0.5  31.1  220  21 11   8.1   4.5 |  -0.6  30.9  175  26 13   5.7   3.1
 15000   0.7  33.3  220  20 10   8.2   4.5 |   0.3  32.5  175  23 12   6.0   3.3
 14500   1.9  35.4  220  19 10   8.2   4.5 |   1.2  34.2  170  20 10   6.4   3.5
 14000   3.2  37.8  220  19 10   8.2   4.5 |   2.1  35.8  170  17  9   6.8   3.7
 13500   4.4  39.9  220  18  9   7.3   4.0 |   3.1  37.6  170  14  7   6.5   3.6
 13000   5.2  41.4  220  17  9   5.8   3.2 |   3.9  39.0  165  11  6   5.4   2.9
 12500   6.0  42.8  215  17  9   5.5   3.0 |   4.7  40.5  165   8  4   5.4   3.0
 12000   6.7  44.1  210  16  8   4.3   2.4 |   5.4  41.7  165   5  3   5.7   3.1
 11500   7.3  45.1  205  15  8   4.5   2.5 |   6.3  43.3  165   3  1   5.7   3.1
 11000   7.9  46.2  195  13  7   4.8   2.6 |   7.1  44.8  125   1  1   5.8   3.2
 10500   8.5  47.3  185  11  6   2.9   1.6 |   7.9  46.2  050   2  1   3.9   2.1
 10250   8.7  47.7  180  11  6   3.3   1.8 |   8.1  46.6  040   2  1   3.4   1.9
 10000   9.0  48.2  165   9  5   7.0   3.8 |   8.5  47.3  040   4  2   7.6   4.2
  9750   9.5  49.1  140   8  4   7.0   3.8 |   9.1  48.4  040   5  3   8.4   4.6
  9500   9.9  49.8  115   8  4   6.6   3.6 |   9.6  49.3  040   7  4   7.9   4.3
  9250  10.3  50.5  100   9  4   5.8   3.2 |  10.1  50.2  040   8  4   6.2   3.4
  9000  10.8  51.4  090   8  4   8.4   4.6 |  10.5  50.9  035   9  5   6.8   3.7
  8750  11.5  52.7  080   9  4  10.4   5.7 |  11.1  52.0  030  10  5   8.1   4.5
  8500  12.2  54.0  075   9  5   9.8   5.4 |  11.6  52.9  030  10  5   7.9   4.4
  8250  12.9  55.2  070   9  5   9.9   5.4 |  12.2  54.0  025  10  5   8.5   4.7
  8000  13.6  56.5  070   9  5   9.8   5.4 |  12.8  55.0  020  11  6   8.2   4.5
  7750  14.3  57.7  070   9  5   9.7   5.3 |  13.4  56.1  015  11  6   7.6   4.2
  7500  15.1  59.2  065   9  5  10.0   5.5 |  13.9  57.0  010  11  6   7.8   4.3
  7250  15.8  60.4  065   9  5  10.3   5.7 |  14.5  58.1  005  12  6   8.0   4.4
  7000  16.6  61.9  065   9  5  10.1   5.6 |  15.1  59.2  360  12  6   7.9   4.4
  6750  17.3  63.1  065   9  4  10.2   5.6 |  15.7  60.3  355  13  7   8.3   4.5
  6500  18.1  64.6  065   9  4  10.4   5.7 |  16.3  61.3  355  13  7   9.4   5.2
  6250  18.9  66.0  065   8  4  11.1   6.1 |  17.0  62.6  350  13  7  10.1   5.6
  6000  19.7  67.5  060   8  4   9.2   5.0 |  17.8  64.0  345  13  7   9.6   5.3
  5750  20.4  68.7  060   8  4  13.1   7.2 |  18.5  65.3  345  13  7  11.0   6.0
  5500  21.8  71.2  060   8  4  25.0  13.7 |  19.4  66.9  345  12  6  14.4   7.9
________________________________________________________________________________

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.