weather.gov     
National Weather Service

Soaring Guidance
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to SR-SRH.Webmaster@noaa.gov with any concerns.


Current Version
Previous Version:    01  02  03  04  05  06  07  08  09  10  11  12  13  14  
[Printable]
131
UXUS97 KBOU 011214
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0614 MDT Wednesday, October 1, 2014

This forecast is for Wednesday, October 1, 2014:

If the trigger temperature of 61.6 F/16.4 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 10 ft/min (0.1 m/s)
   Maximum height of thermals.................. 10585 ft MSL (5300 ft AGL)

Forecast maximum temperature................... 63.0 F/17.7 C
Time of trigger temperature.................... 1130 MDT
Time of overdevelopment........................ None
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................. 5893 ft MSL (608 ft AGL)
Thermal soaring outlook for Thursday 10/02..... 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)................ Neither
Potential height of wave....................... 15890 ft MSL (10605 ft AGL)
Wave soaring outlook for Thursday 10/02........ Poor

Remarks... Low pressure trough will move east across coloraod today as a cold
           front drops south through eastern colorado.

Sunrise/Sunset.................... 06:55:45 / 18:43:23 MDT
Total possible sunshine........... 11 hr 47 min 38 sec (707 min 38 sec)
Altitude of sun at 12:49:04 MDT... 46.87 degrees

Upper air data from rawinsonde observation taken on 10/01/2014 at 0600 MDT

Freezing level.................. 11222 ft MSL (5937 ft AGL)
Convective condensation level... 15132 ft MSL (9847 ft AGL)
Lifted condensation level....... 13269 ft MSL (7984 ft AGL)
Lifted index.................... +4.2
K index......................... +12.7

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  -59.5 -75.1   245   49   25   8.7   4.8   97.0 206.6    46.0      M    M
 45000  -54.6 -66.3   250   50   26  -4.2  -2.3   80.9 177.6    39.3      M    M
 40000  -50.1 -58.2   260   58   30   4.2   2.3   64.9 148.8    31.4      M    M
 38000  -48.9 -56.0   260   73   38  -5.8  -3.2   58.0 136.4    27.6      M    M
 36000  -50.0 -58.0   255   65   34   2.8   1.5   47.7 117.9    21.2      M    M
 34000  -47.9 -54.2   250   58   30   4.7   2.6   41.4 106.5    17.3      M    M
 32000  -44.9 -48.8   250   54   28  -0.8  -0.4   37.5  99.5    14.9      M    M
 30000  -41.4 -42.5   250   48   25   8.9   4.9   34.3  93.7    12.8      M    M
 29000  -38.8 -37.8   250   45   23   9.0   5.0   33.9  93.1    12.7      M    M
 28000  -36.3 -33.3   245   43   22   7.8   4.3   33.3  91.9    12.4      M    M
 27000  -34.0 -29.2   245   41   21   7.1   3.9   32.5  90.5    11.9      M    M
 26000  -31.5 -24.7   245   38   20   9.2   5.1   32.0  89.6    11.7      M    M
 25000  -28.7 -19.7   240   36   19   8.8   4.8   31.8  89.2    11.7      M    M
 24000  -26.1 -15.0   240   35   18   8.2   4.5   31.4  88.6    11.5      M    M
 23000  -23.7 -10.7   240   34   17   7.7   4.2   30.6  87.1    11.0      M    M
 22000  -21.4  -6.5   240   33   17   7.1   3.9   29.9  85.9    10.6      M    M
 21000  -19.9  -3.8   240   31   16   7.0   3.8   28.3  83.0     9.3      M    M
 20000  -17.8  -0.0   240   30   15   7.4   4.1   27.3  81.2     8.5      M    M
 19500  -17.0   1.4   240   28   14   1.8   1.0   26.5  79.7     7.9      M    M
 19000  -16.8   1.8   245   25   13   2.8   1.5   25.1  77.2     6.7      M    M
 18500  -15.8   3.6   250   23   12   9.1   5.0   24.6  76.3     6.2      M    M
 18000  -14.6   5.7   250   21   11   8.1   4.4   24.3  75.7     6.0      M    M
 17500  -13.6   7.5   250   19   10   5.7   3.1   23.8  74.8     5.6      M    M
 17000  -12.1  10.2   250   16    8   9.1   5.0   23.1  73.5     4.9      M    M
 16500  -10.8  12.6   250   14    7   8.9   4.9   22.9  73.3     4.8      M    M
 16000   -9.5  14.9   255   12    6   8.9   4.9   22.8  73.1     4.7      M    M
 15500   -8.1  17.4   265   12    6   8.9   4.9   22.6  72.8     4.6      M    M
 15000   -6.8  19.8   275   12    6   8.8   4.8   22.5  72.5     4.5      M    M
 14500   -5.5  22.1   280   13    6   7.9   4.3   22.3  72.2     4.3      M    M
 14000   -4.6  23.7   285   13    7   5.5   3.0   21.7  71.1     3.8      M    M
 13500   -3.8  25.2   275   13    7   5.6   3.1   21.0  69.8     3.1      M    M
 13000   -3.0  26.6   265   14    7   5.6   3.1   20.3  68.6     2.4      M    M
 12500   -2.2  28.0   255   15    8   5.6   3.1   19.7  67.4     1.8      M    M
 12000   -1.4  29.5   250   16    8   5.5   3.0   19.0  66.3     1.2      M    M
 11500   -0.5  31.1   260   17    9   7.4   4.0   18.5  65.2     0.6      M    M
 11000    0.6  33.1   270   19   10   7.4   4.1   18.1  64.6     0.3      M    M
 10500    1.7  35.1   270   17    9   7.1   3.9   17.7  63.9    -0.1    398  2.0
 10250    2.2  36.0   270   16    8   6.3   3.4   17.5  63.5    -0.3    376  1.9
 10000    2.7  36.9   270   15    8   7.8   4.3   17.3  63.1    -0.6    354  1.8
  9750    3.3  37.9   275   15    8   9.2   5.0   17.2  62.9    -0.6    327  1.7
  9500    4.0  39.2   275   14    7   8.8   4.8   17.1  62.8    -0.7    300  1.5
  9250    4.6  40.3   280   14    7   8.9   4.9   17.1  62.7    -0.8    273  1.4
  9000    5.3  41.5   280   14    7   8.9   4.9   17.0  62.6    -0.8    245  1.2
  8750    6.0  42.8   280   13    7   8.9   4.9   16.9  62.5    -0.9    218  1.1
  8500    6.6  43.9   280   11    6   8.9   4.9   16.9  62.4    -1.0    191  1.0
  8250    7.3  45.1   280   10    5   8.9   4.9   16.8  62.2    -1.1    164  0.8
  8000    7.9  46.2   280    9    5   8.9   4.9   16.7  62.1    -1.1    137  0.7
  7750    8.6  47.5   280    8    4   8.9   4.9   16.7  62.0    -1.2    109  0.6
  7500    9.3  48.7   280    7    3   8.9   4.9   16.6  61.9    -1.3     82  0.4
  7250    9.9  49.8   275    5    3   8.8   4.8   16.5  61.7    -1.4     55  0.3
  7000   10.6  51.1   275    4    2   9.0   4.9   16.5  61.6    -1.4     28  0.1
  6750   11.2  52.2   255    3    2   8.4   4.6   16.4  61.5    -1.5      0  0.0
  6500   11.8  53.2   220    3    1   5.7   3.1   16.2  61.1    -1.7      M    M
  6250   12.2  54.0   190    4    2   6.1   3.4   15.8  60.5    -2.1      M    M
  6000   12.5  54.5   175    5    3   1.2   0.7   15.5  59.9    -2.5      M    M
  5750   12.3  54.1   175    3    2  -5.7  -3.1   14.5  58.1    -3.5      M    M
  5500   11.5  52.7   175    2    1 -16.6  -9.1   13.1  55.5    -5.0      M    M

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

           10/01/2014 at 0900 MDT          |       10/01/2014 at 1200 MDT
                                           |
K index... +24.9  LI... -0.0               | K index... +16.2  LI... -0.3
CAPE... +0.9  CIN... -2.7                  | CAPE... +21.3  CIN... -7.0
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -58.5 -73.3  240  32 16   2.6   1.4 | -57.3 -71.1  235  35 18   2.1   1.2
 45000 -54.5 -66.1  245  49 25   3.2   1.7 | -54.0 -65.2  240  57 29   2.5   1.4
 40000 -49.7 -57.5  255  68 35   3.2   1.8 | -50.3 -58.5  255  69 35   2.5   1.4
 38000 -48.5 -55.3  255  70 36   1.5   0.8 | -49.0 -56.2  255  72 37   2.1   1.2
 36000 -47.6 -53.7  255  70 36   1.5   0.8 | -47.7 -53.9  255  74 38   2.1   1.2
 34000 -46.2 -51.2  255  65 34   3.4   1.8 | -46.3 -51.3  255  73 37   3.1   1.7
 32000 -44.2 -47.6  255  54 28   3.4   1.8 | -44.2 -47.6  255  59 30   3.1   1.7
 30000 -41.4 -42.5  255  45 23   7.3   4.0 | -41.6 -42.9  250  47 24   6.7   3.7
 29000 -39.2 -38.6  255  42 22   7.4   4.0 | -39.6 -39.3  250  42 22   6.7   3.7
 28000 -37.0 -34.6  250  39 20   7.4   4.0 | -37.6 -35.7  250  36 19   6.7   3.7
 27000 -34.7 -30.5  250  37 19   8.3   4.6 | -35.5 -31.9  250  31 16   8.2   4.5
 26000 -32.2 -26.0  255  36 19   8.5   4.6 | -33.0 -27.4  250  31 16   8.4   4.6
 25000 -29.7 -21.5  255  35 18   8.5   4.7 | -30.5 -22.9  255  30 15   8.5   4.6
 24000 -27.1 -16.8  260  34 18   7.8   4.3 | -28.0 -18.4  255  29 15   8.4   4.6
 23000 -25.0 -13.0  260  32 17   7.0   3.8 | -25.5 -13.9  255  29 15   8.3   4.5
 22000 -22.9  -9.2  265  31 16   7.0   3.9 | -23.1  -9.6  260  29 15   8.3   4.6
 21000 -20.8  -5.4  265  29 15   5.9   3.2 | -20.6  -5.1  260  29 15   7.5   4.1
 20000 -19.2  -2.6  265  26 13   5.7   3.1 | -18.5  -1.3  265  27 14   7.4   4.0
 19500 -18.3  -0.9  260  24 12   5.7   3.1 | -17.4   0.7  265  27 14   7.4   4.0
 19000 -17.5   0.5  260  23 12   5.7   3.1 | -16.3   2.7  265  26 13   7.4   4.0
 18500 -16.6   2.1  255  21 11   6.4   3.5 | -15.2   4.6  265  25 13   7.2   4.0
 18000 -15.7   3.7  250  20 10   6.9   3.8 | -14.1   6.6  265  25 13   7.1   3.9
 17500 -14.7   5.5  245  19 10   7.0   3.8 | -13.0   8.6  265  24 12   7.1   3.9
 17000 -13.6   7.5  240  19 10   7.5   4.1 | -12.1  10.2  260  23 12   6.0   3.3
 16500 -12.0  10.4  235  18  9   7.4   4.1 | -11.1  12.0  260  22 11   6.1   3.3
 16000 -11.0  12.2  230  18  9   7.0   3.8 |  -9.7  14.5  255  20 11   6.4   3.5
 15500 -10.0  14.0  230  17  9   7.1   3.9 |  -8.8  16.2  250  19 10   6.3   3.4
 15000  -9.0  15.8  225  16  8   6.4   3.5 |  -7.8  18.0  245  18  9   7.3   4.0
 14500  -8.0  17.6  220  14  7   6.4   3.5 |  -6.7  19.9  240  18  9   7.3   4.0
 14000  -7.1  19.2  220  13  7   7.5   4.1 |  -5.7  21.7  235  18  9   7.5   4.1
 13500  -5.9  21.4  210  12  6   7.7   4.2 |  -4.5  23.9  230  17  9   7.5   4.1
 13000  -4.8  23.4  205  12  6   7.9   4.3 |  -3.5  25.7  225  17  9   7.2   4.0
 12500  -3.6  25.5  200  11  6   8.0   4.4 |  -2.4  27.7  220  17  9   7.1   3.9
 12000  -2.4  27.7  195  11  5   8.5   4.7 |  -1.4  29.5  215  17  9   7.6   4.2
 11500  -1.1  30.0  195  10  5   8.8   4.8 |  -0.2  31.6  210  17  9   8.0   4.4
 11000   0.2  32.4  195   9  4   7.9   4.3 |   1.0  33.8  200  17  9   7.5   4.1
 10500   1.3  34.3  190   8  4   6.6   3.6 |   2.0  35.6  195  16  8   6.5   3.5
 10250   1.8  35.2  185   8  4  10.4   5.7 |   2.5  36.5  190  16  8   9.4   5.2
 10000   2.7  36.9  185   8  4  11.1   6.1 |   3.2  37.8  185  16  8  10.2   5.6
  9750   3.4  38.1  185   8  4   7.8   4.3 |   3.8  38.8  180  15  8   7.9   4.3
  9500   4.0  39.2  180   8  4   8.9   4.9 |   4.4  39.9  170  14  7   8.4   4.6
  9250   4.7  40.5  180   8  4   7.8   4.3 |   5.0  41.0  165  14  7   8.8   4.8
  9000   5.2  41.4  180   8  4   7.8   4.3 |   5.7  42.3  160  13  7   9.2   5.0
  8750   5.8  42.4  180   8  4   8.8   4.8 |   6.3  43.3  160  13  6   9.0   4.9
  8500   6.5  43.7  180   7  4   8.4   4.6 |   7.0  44.6  155  12  6   8.6   4.7
  8250   7.1  44.8  175   7  4   9.1   5.0 |   7.6  45.7  150  12  6  10.4   5.7
  8000   7.8  46.0  175   7  4   9.0   5.0 |   8.5  47.3  150  11  6  11.4   6.3
  7750   8.4  47.1  175   6  3   7.5   4.1 |   9.2  48.6  150  11  6   9.5   5.2
  7500   9.0  48.2  175   6  3   7.0   3.9 |   9.9  49.8  150  11  6   8.7   4.8
  7250   9.5  49.1  170   5  3   8.2   4.5 |  10.6  51.1  150  11  6   9.8   5.4
  7000  10.2  50.4  170   5  2   8.8   4.8 |  11.3  52.3  150  11  5  10.5   5.8
  6750  10.8  51.4  170   4  2   7.9   4.3 |  12.1  53.8  150  10  5   9.4   5.1
  6500  11.3  52.3  165   4  2   6.0   3.3 |  12.8  55.0  150  10  5   9.6   5.3
  6250  11.7  53.1  170   3  2   3.9   2.1 |  13.6  56.5  145  10  5  11.2   6.1
  6000  11.9  53.4  175   2  1   3.4   1.9 |  14.4  57.9  145  10  5  12.1   6.6
  5750  12.1  53.8  195   2  1   1.7   1.0 |  15.3  59.5  145   9  5   9.6   5.3
  5500  12.1  53.8  230   2  1   1.8   1.0 |  16.0  60.8  145   9  4  12.3   6.8

           10/01/2014 at 1500 MDT          |       10/01/2014 at 1800 MDT
                                           |
K index... +27.9  LI... -0.4               | K index... +16.9  LI... -0.3
CAPE... +38.4  CIN... -13.7                | CAPE... +40.0  CIN... -102.0
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -57.5 -71.5  250  39 20   2.3   1.3 | -57.2 -71.0  250  37 19   2.4   1.3
 45000 -54.2 -65.6  250  60 31   1.7   1.0 | -53.7 -64.7  255  56 29   0.4   0.2
 40000 -51.6 -60.9  250  68 35   1.7   0.9 | -53.1 -63.6  245  64 33   0.4   0.2
 38000 -50.8 -59.4  250  69 36   1.0   0.6 | -52.4 -62.3  240  64 33   1.6   0.9
 36000 -50.2 -58.4  250  70 36   1.0   0.6 | -51.5 -60.7  245  62 32   1.6   0.9
 34000 -49.0 -56.2  250  66 34   4.9   2.7 | -49.9 -57.8  245  59 31   6.2   3.4
 32000 -45.6 -50.1  245  50 26   5.0   2.7 | -45.7 -50.3  240  56 29   6.2   3.4
 30000 -41.8 -43.2  245  40 21   8.8   4.8 | -41.6 -42.9  240  52 27   7.5   4.1
 29000 -39.2 -38.6  245  39 20   8.8   4.8 | -39.4 -38.9  235  50 26   7.5   4.1
 28000 -36.6 -33.9  245  38 19   8.8   4.8 | -37.1 -34.8  235  47 24   7.5   4.1
 27000 -34.0 -29.2  245  37 19   8.3   4.5 | -34.8 -30.6  230  45 23   8.7   4.8
 26000 -31.5 -24.7  250  36 19   8.3   4.5 | -32.2 -26.0  235  42 22   8.7   4.8
 25000 -29.0 -20.2  250  36 19   8.3   4.6 | -29.6 -21.3  235  39 20   8.7   4.8
 24000 -26.6 -15.9  255  36 19   7.8   4.3 | -27.0 -16.6  235  36 18   8.0   4.4
 23000 -24.4 -11.9  255  34 18   7.5   4.1 | -24.8 -12.6  235  34 17   7.6   4.2
 22000 -22.1  -7.8  250  32 17   7.5   4.1 | -22.5  -8.5  235  32 17   7.6   4.2
 21000 -19.9  -3.8  250  30 16   7.3   4.0 | -20.3  -4.5  235  30 16   6.9   3.8
 20000 -17.8  -0.0  245  29 15   7.3   4.0 | -18.3  -0.9  240  28 14   6.9   3.8
 19500 -16.7   1.9  240  29 15   7.3   4.0 | -17.3   0.9  240  27 14   6.9   3.8
 19000 -15.7   3.7  240  29 15   7.3   4.0 | -16.3   2.7  240  26 13   6.9   3.8
 18500 -14.6   5.7  235  29 15   6.8   3.7 | -15.3   4.5  240  25 13   5.8   3.2
 18000 -13.6   7.5  230  29 15   6.6   3.6 | -14.5   5.9  245  23 12   5.3   2.9
 17500 -12.7   9.1  225  29 15   6.6   3.6 | -13.7   7.3  245  21 11   5.3   2.9
 17000 -11.7  10.9  220  29 15   6.9   3.8 | -12.9   8.8  250  20 10   5.8   3.2
 16500 -10.7  12.7  215  28 15   6.9   3.8 | -12.0  10.4  250  19 10   5.7   3.1
 16000  -9.3  15.3  205  26 14   6.2   3.4 | -10.5  13.1  260  19 10   7.8   4.3
 15500  -8.4  16.9  200  24 13   6.2   3.4 |  -9.4  15.1  260  19 10   7.5   4.1
 15000  -7.5  18.5  195  22 12   6.4   3.5 |  -8.1  17.4  265  19 10   9.8   5.4
 14500  -6.5  20.3  190  20 10   6.4   3.5 |  -6.6  20.1  270  20 10   9.6   5.3
 14000  -5.6  21.9  185  18  9   6.4   3.5 |  -5.2  22.6  270  20 10   8.6   4.7
 13500  -4.7  23.5  185  16  8   6.4   3.5 |  -4.0  24.8  275  20 10   8.5   4.7
 13000  -3.8  25.2  185  14  7   6.7   3.7 |  -2.7  27.1  275  20 11   7.9   4.3
 12500  -2.8  27.0  185  12  6   6.9   3.8 |  -1.6  29.1  280  20 10   7.6   4.2
 12000  -1.8  28.8  190   9  5   7.9   4.3 |  -0.5  31.1  285  20 10   7.6   4.2
 11500  -0.5  31.1  195   8  4   8.7   4.8 |   0.7  33.3  290  19 10   7.6   4.2
 11000   0.8  33.4  200   7  3   9.0   4.9 |   1.8  35.2  295  18 10   6.7   3.7
 10500   2.2  36.0  205   6  3   8.6   4.7 |   2.6  36.7  300  18  9   5.8   3.2
 10250   2.9  37.2  210   6  3  12.0   6.6 |   3.1  37.6  300  18  9   7.3   4.0
 10000   4.0  39.2  215   6  3  12.2   6.7 |   3.7  38.7  305  18  9   7.9   4.3
  9750   4.7  40.5  215   6  3   9.1   5.0 |   4.2  39.6  305  18  9   6.6   3.6
  9500   5.4  41.7  220   5  3   9.7   5.3 |   4.7  40.5  310  18  9   7.0   3.8
  9250   6.1  43.0  225   5  3  10.3   5.7 |   5.2  41.4  310  18  9   6.8   3.7
  9000   6.9  44.4  230   5  3  10.6   5.8 |   5.6  42.1  315  18  9   6.0   3.3
  8750   7.7  45.9  235   5  3   9.9   5.4 |   6.0  42.8  320  17  9   5.5   3.0
  8500   8.4  47.1  240   5  3   9.9   5.4 |   6.4  43.5  325  16  8   5.5   3.0
  8250   9.2  48.6  245   5  3  10.5   5.7 |   6.8  44.2  330  16  8   6.0   3.3
  8000  10.0  50.0  250   5  2  10.4   5.7 |   7.2  45.0  335  15  8   5.9   3.2
  7750  10.7  51.3  255   5  2   9.4   5.2 |   7.6  45.7  340  15  8   4.1   2.3
  7500  11.4  52.5  260   5  3   9.0   5.0 |   7.8  46.0  350  15  8   3.4   1.9
  7250  12.1  53.8  265   5  3   9.9   5.5 |   8.1  46.6  355  16  8   4.6   2.5
  7000  12.9  55.2  270   5  3  10.7   5.9 |   8.4  47.1  360  16  8   5.6   3.1
  6750  13.7  56.7  270   5  3   9.8   5.4 |   8.7  47.7  005  17  9   5.1   2.8
  6500  14.4  57.9  275   6  3   9.8   5.4 |   9.0  48.2  010  16  8   6.9   3.8
  6250  15.2  59.4  280   6  3  10.8   5.9 |   9.6  49.3  010  16  8  10.0   5.5
  6000  16.0  60.8  285   6  3  11.4   6.3 |  10.4  50.7  010  15  8  10.8   5.9
  5750  16.8  62.2  285   6  3   9.5   5.2 |  11.1  52.0  010  14  7   9.5   5.2
  5500  17.5  63.5  290   6  3  10.2   5.6 |  11.8  53.2  010  13  6   9.9   5.5
________________________________________________________________________________

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




U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE