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
000
UXUS97 KBOU 270040
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1740 MST Wednesday, November 26, 2014

This forecast is for Thursday, November 27, 2014:

If the trigger temperature of 64.9 F/18.3 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 159 ft/min (0.8 m/s)
   Maximum height of thermals.................. 10104 ft MSL (4817 ft AGL)

Forecast maximum temperature................... 66.0 F/19.3 C
Time of trigger temperature.................... 1315 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast opaque high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8094 ft MSL (2806 ft AGL)
Thermal soaring outlook for Friday 11/28....... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... None
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1700 MST)................ Weak NVA
Potential height of wave....................... 24472 ft MSL (19185 ft AGL)
Wave soaring outlook for Friday 11/28.......... Good

Remarks... None

Sunrise/Sunset.................... 06:57:26 / 16:36:51 MST
Total possible sunshine........... 9 hr 39 min 25 sec (579 min 25 sec)
Altitude of sun at 11:47:17 MST... 29.08 degrees

Upper air data from numerical model forecast valid on 11/27/2014 at 0500 MST

Freezing level.................. 5290 ft MSL (3 ft AGL)
Additional freezing level....... 12021 ft MSL (6734 ft AGL)
Convective condensation level... 20579 ft MSL (15292 ft AGL)
Lifted condensation level....... 17913 ft MSL (12626 ft AGL)
Lifted index.................... +6.0
K index......................... -10.1

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  -66.4 -87.5   305   48   25   0.5   0.3      M     M       M      M    M
 45000  -65.3 -85.5   305   68   35   3.3   1.8      M     M       M      M    M
 40000  -60.4 -76.7   315   75   39   3.3   1.8      M     M       M      M    M
 38000  -57.9 -72.2   315   76   39   4.5   2.5      M     M       M      M    M
 36000  -55.2 -67.4   315   76   39   4.5   2.5      M     M       M      M    M
 34000  -51.5 -60.7   310   72   37   8.8   4.8      M     M       M      M    M
 32000  -46.2 -51.2   300   64   33   8.8   4.8      M     M       M      M    M
 30000  -40.4 -40.7   295   58   30   8.6   4.7   35.3  95.5    12.3      M    M
 29000  -37.8 -36.0   300   56   29   8.6   4.7   34.8  94.6    12.1      M    M
 28000  -35.2 -31.4   300   54   28   8.6   4.7   34.5  94.0    12.0      M    M
 27000  -32.9 -27.2   305   54   28   6.7   3.7   33.7  92.6    11.5      M    M
 26000  -31.0 -23.8   310   55   28   6.7   3.7   32.4  90.3    10.6      M    M
 25000  -29.0 -20.2   315   57   29   6.7   3.7   31.3  88.4     9.9      M    M
 24000  -27.0 -16.6   315   58   30   6.6   3.6   30.2  86.4     9.1      M    M
 23000  -25.0 -13.0   315   58   30   6.6   3.6   29.0  84.2     8.2      M    M
 22000  -23.0  -9.4   315   58   30   6.6   3.6   27.9  82.2     7.4      M    M
 21000  -20.9  -5.6   320   56   29   7.5   4.1   26.9  80.5     6.7      M    M
 20000  -18.6  -1.5   320   54   28   7.6   4.1   26.1  79.0     6.1      M    M
 19500  -17.5   0.5   320   52   27   7.6   4.1   25.8  78.4     5.8      M    M
 19000  -16.4   2.5   320   51   26   7.5   4.1   25.4  77.8     5.5      M    M
 18500  -15.3   4.5   320   50   26   7.3   4.0   25.0  77.0     5.2      M    M
 18000  -14.2   6.4   320   48   25   7.2   4.0   24.6  76.3     4.8      M    M
 17500  -13.1   8.4   320   46   24   8.1   4.4   24.2  75.6     4.5      M    M
 17000  -11.8  10.8   320   43   22   8.2   4.5   24.0  75.1     4.3      M    M
 16500  -10.6  12.9   320   40   21   8.0   4.4   23.7  74.7     4.1      M    M
 16000   -9.4  15.1   320   37   19   7.6   4.2   23.4  74.1     3.8      M    M
 15500   -8.3  17.1   320   34   18   7.6   4.2   23.0  73.4     3.6      M    M
 15000   -6.5  20.3   315   28   15   8.1   4.5   22.6  72.6     3.2      M    M
 14500   -5.2  22.6   310   25   13   7.9   4.3   22.3  72.2     3.0      M    M
 14000   -4.1  24.6   310   22   11   7.3   4.0   21.9  71.5     2.7      M    M
 13500   -3.0  26.6   305   19   10   7.3   4.0   21.6  70.8     2.3      M    M
 13000   -2.0  28.4   305   16    8   6.9   3.8   21.1  70.0     1.9      M    M
 12500   -0.9  30.4   305   13    7   7.0   3.9   20.7  69.2     1.5      M    M
 12000    0.2  32.4   305   12    6   8.6   4.7   20.4  68.6     1.2      M    M
 11500    1.5  34.7   305   11    6   8.4   4.6   20.1  68.3     1.0      M    M
 11000    2.7  36.9   310   11    6   7.7   4.2   19.9  67.8     0.8      M    M
 10500    3.9  39.0   315   12    6   7.3   4.0   19.6  67.2     0.5      M    M
 10250    4.3  39.7   320   13    7   3.5   1.9   19.3  66.7     0.2      M    M
 10000    4.6  40.3   320   14    7   6.0   3.3   18.8  65.8    -0.3    350  1.8
  9750    5.2  41.4   320   16    8  10.4   5.7   18.7  65.7    -0.3    323  1.6
  9500    5.9  42.6   320   19   10   8.0   4.4   18.7  65.6    -0.4    295  1.5
  9250    6.4  43.5   315   21   11   5.0   2.8   18.4  65.2    -0.6    273  1.4
  9000    6.7  44.1   315   23   12   3.9   2.1   18.0  64.4    -1.1    256  1.3
  8750    7.0  44.6   310   25   13   5.1   2.8   17.6  63.6    -1.5    239  1.2
  8500    7.4  45.3   310   27   14   2.8   1.5   17.2  62.9    -1.9    222  1.1
  8250    7.4  45.3   305   28   14  -0.0  -0.0   16.5  61.7    -2.6    213  1.1
  8000    7.4  45.3   300   29   15   0.1   0.0   15.7  60.3    -3.3    206  1.0
  7750    7.4  45.3   295   30   16  -0.7  -0.4   15.0  58.9    -4.1    200  1.0
  7500    7.2  45.0   295   30   15  -2.0  -1.1   14.1  57.4    -5.0    196  1.0
  7250    7.0  44.6   290   27   14  -2.3  -1.2   13.2  55.7    -5.9    195  1.0
  7000    6.8  44.2   285   24   13  -2.6  -1.4   12.3  54.1    -6.8    193  1.0
  6750    6.6  43.9   280   22   11  -1.0  -0.5   11.4  52.4    -7.8    192  1.0
  6500    6.6  43.9   275   18    9   0.7   0.4   10.6  51.1    -8.5    184  0.9
  6250    6.7  44.1   265   15    8   3.9   2.2   10.0  50.0    -9.2    174  0.9
  6000    6.9  44.4   255   12    6  -7.0  -3.9    9.4  48.9    -9.8    163  0.8
  5750    5.3  41.5   235   11    6 -30.3 -16.6    7.2  44.9   -12.1    202  1.0
  5500    2.7  36.9   215    9    4 -36.0 -19.8    3.9  38.9   -15.5    275  1.4

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

           11/27/2014 at 0800 MST          |       11/27/2014 at 1100 MST
                                           |
K index... +4.9  LI... +2.8                | K index... +8.9  LI... +2.5
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... M
                                           |
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 -66.6 -87.9  305  55 28   2.1   1.1 | -66.0 -86.8  295  53 27   1.6   0.9
 45000 -63.3 -81.9  305  60 31   2.9   1.6 | -63.5 -82.3  300  66 34   3.1   1.7
 40000 -59.1 -74.4  310  69 35   2.8   1.6 | -58.9 -74.0  310  70 36   3.0   1.7
 38000 -57.1 -70.8  310  71 37   3.4   1.9 | -57.1 -70.8  310  71 37   3.1   1.7
 36000 -55.0 -67.0  310  73 37   3.4   1.9 | -55.2 -67.4  305  72 37   3.1   1.7
 34000 -51.8 -61.2  305  71 37   9.0   4.9 | -51.3 -60.3  305  69 36   9.5   5.2
 32000 -45.7 -50.3  295  63 32   8.9   4.9 | -45.6 -50.1  300  62 32   9.5   5.2
 30000 -40.6 -41.1  295  57 29   8.2   4.5 | -40.2 -40.4  300  57 29   8.3   4.6
 29000 -38.1 -36.6  300  54 28   8.2   4.5 | -37.7 -35.9  300  54 28   8.3   4.6
 28000 -35.7 -32.3  305  52 27   8.2   4.5 | -35.2 -31.4  300  52 27   8.3   4.5
 27000 -33.4 -28.1  305  51 26   6.8   3.7 | -33.0 -27.4  300  49 25   6.0   3.3
 26000 -31.4 -24.5  310  54 28   6.8   3.7 | -31.2 -24.2  305  45 23   6.1   3.3
 25000 -29.3 -20.7  310  56 29   6.8   3.7 | -29.4 -20.9  305  42 21   6.1   3.3
 24000 -27.3 -17.1  310  57 29   6.2   3.4 | -27.5 -17.5  310  40 20   6.6   3.6
 23000 -25.5 -13.9  310  55 29   6.3   3.4 | -25.6 -14.1  310  40 21   6.6   3.6
 22000 -23.6 -10.5  310  54 28   6.3   3.5 | -23.6 -10.5  310  41 21   6.6   3.6
 21000 -21.6  -6.9  315  51 26   7.2   3.9 | -21.5  -6.7  310  41 21   7.7   4.2
 20000 -19.5  -3.1  315  47 24   7.2   3.9 | -19.2  -2.6  310  41 21   7.7   4.2
 19500 -18.4  -1.1  315  45 23   7.2   3.9 | -18.1  -0.6  310  41 21   7.7   4.2
 19000 -17.3   0.9  315  43 22   7.2   4.0 | -16.9   1.6  310  41 21   7.7   4.2
 18500 -16.2   2.8  315  41 21   7.7   4.2 | -15.8   3.6  310  40 21   8.0   4.4
 18000 -15.1   4.8  315  39 20   7.7   4.2 | -14.6   5.7  310  39 20   8.0   4.4
 17500 -13.9   7.0  320  38 19   7.6   4.2 | -13.4   7.9  310  38 19   8.2   4.5
 17000 -12.8   9.0  320  35 18   7.6   4.2 | -12.1  10.2  310  37 19   8.2   4.5
 16500 -11.6  11.1  320  33 17   7.9   4.3 | -10.3  13.5  310  37 19   7.9   4.3
 16000  -9.8  14.4  320  30 16   8.4   4.6 |  -9.1  15.6  310  36 18   7.9   4.3
 15500  -8.5  16.7  315  29 15   8.7   4.8 |  -7.9  17.8  310  35 18   8.0   4.4
 15000  -7.2  19.0  315  27 14   8.9   4.9 |  -6.7  19.9  310  35 18   8.2   4.5
 14500  -5.8  21.6  315  26 13   8.9   4.9 |  -5.5  22.1  310  35 18   8.1   4.5
 14000  -4.5  23.9  315  25 13   8.8   4.8 |  -4.3  24.3  310  35 18   8.1   4.4
 13500  -3.2  26.2  315  24 12   8.8   4.8 |  -3.1  26.4  310  34 18   8.1   4.4
 13000  -1.8  28.8  315  22 11   8.8   4.8 |  -1.9  28.6  305  34 18   8.0   4.4
 12500  -0.5  31.1  315  19 10   8.8   4.8 |  -0.7  30.7  305  34 18   8.0   4.4
 12000   0.8  33.4  315  18  9   9.2   5.0 |   0.4  32.7  305  34 17   7.7   4.2
 11500   2.2  36.0  320  18  9   9.1   5.0 |   1.6  34.9  305  32 17   7.7   4.3
 11000   3.6  38.5  320  18  9   9.0   5.0 |   2.8  37.0  305  32 16   8.9   4.9
 10500   4.9  40.8  320  18  9   8.2   4.5 |   4.2  39.6  305  32 17   7.7   4.2
 10250   5.4  41.7  325  19 10   4.6   2.5 |   4.6  40.3  300  32 17   3.9   2.2
 10000   5.8  42.4  320  20 10   7.6   4.2 |   4.9  40.8  300  32 16   7.4   4.0
  9750   6.5  43.7  320  21 11  11.7   6.4 |   5.7  42.3  300  31 16  11.4   6.3
  9500   7.3  45.1  320  23 12   9.5   5.2 |   6.5  43.7  300  30 15   9.5   5.2
  9250   7.9  46.2  320  24 12   6.9   3.8 |   7.1  44.8  300  29 15   7.1   3.9
  9000   8.4  47.1  320  25 13   6.3   3.4 |   7.6  45.7  300  28 15   7.7   4.2
  8750   8.9  48.0  320  26 13   7.6   4.1 |   8.3  46.9  295  28 14   9.8   5.4
  8500   9.5  49.1  315  28 14   5.9   3.2 |   9.0  48.2  295  27 14   8.6   4.7
  8250   9.8  49.6  310  29 15   3.9   2.1 |   9.6  49.3  295  27 14   7.4   4.0
  8000  10.1  50.2  310  30 15   3.7   2.0 |  10.2  50.4  290  27 14   7.6   4.2
  7750  10.3  50.5  305  31 16   2.6   1.4 |  10.8  51.4  290  27 14   8.0   4.4
  7500  10.4  50.7  300  32 16  -1.0  -0.5 |  11.4  52.5  285  27 14   6.9   3.8
  7250  10.2  50.4  295  30 15  -3.3  -1.8 |  11.8  53.2  285  26 13   5.7   3.1
  7000  10.0  50.0  295  28 14  -2.2  -1.2 |  12.3  54.1  280  26 13   6.6   3.6
  6750   9.8  49.6  290  26 14  -3.0  -1.6 |  12.7  54.9  280  25 13   4.1   2.2
  6500   9.5  49.1  285  23 12  -6.5  -3.6 |  12.8  55.0  275  23 12  -0.7  -0.4
  6250   8.9  48.0  280  18 10  -4.8  -2.7 |  12.8  55.0  270  20 10   1.4   0.8
  6000   8.4  47.1  270  15  7 -14.6  -8.0 |  12.7  54.9  265  18  9  -8.4  -4.6
  5750   6.5  43.7  250  11  6 -32.5 -17.8 |  11.2  52.2  255  15  8 -26.8 -14.7
  5500   3.9  39.0  230   8  4 -31.9 -17.5 |   9.0  48.2  245  10  5 -26.8 -14.7

           11/27/2014 at 1400 MST          |       11/27/2014 at 1700 MST
                                           |
K index... +3.9  LI... +4.9                | K index... +3.3  LI... +6.5
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.1
                                           |
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 -65.2 -85.4  300  58 30  -0.3  -0.2 | -64.9 -84.8  305  65 33  -0.6  -0.3
 45000 -65.2 -85.4  300  68 35   4.1   2.3 | -65.5 -85.9  300  76 39   2.6   1.4
 40000 -59.4 -74.9  305  66 34   3.9   2.1 | -61.8 -79.2  310  68 35   2.5   1.4
 38000 -57.3 -71.1  305  69 36   3.5   1.9 | -59.0 -74.2  310  70 36   5.5   3.0
 36000 -55.2 -67.4  310  74 38   3.5   1.9 | -55.8 -68.4  310  72 37   5.5   3.0
 34000 -51.8 -61.2  310  73 38   9.2   5.1 | -51.6 -60.9  310  69 35   9.4   5.2
 32000 -46.3 -51.3  300  63 32   9.2   5.0 | -46.0 -50.8  300  57 29   9.4   5.1
 30000 -40.2 -40.4  295  54 28   8.9   4.9 | -39.7 -39.5  295  50 26   9.1   5.0
 29000 -37.5 -35.5  295  52 27   8.9   4.9 | -37.0 -34.6  300  49 25   9.1   5.0
 28000 -34.9 -30.8  295  50 26   8.8   4.9 | -34.3 -29.7  300  48 25   9.0   5.0
 27000 -32.5 -26.5  295  46 24   6.7   3.6 | -31.6 -24.9  300  47 24   8.7   4.8
 26000 -30.6 -23.1  295  42 21   6.6   3.6 | -29.1 -20.4  305  44 23   8.7   4.8
 25000 -28.6 -19.5  295  37 19   6.6   3.6 | -26.5 -15.7  305  42 22   8.7   4.8
 24000 -26.5 -15.7  300  34 17   8.0   4.4 | -24.1 -11.4  305  40 21   6.7   3.6
 23000 -24.1 -11.4  300  35 18   7.9   4.3 | -22.0  -7.6  305  39 20   6.8   3.7
 22000 -21.8  -7.2  305  35 18   7.9   4.3 | -20.0  -4.0  310  38 20   6.8   3.8
 21000 -19.4  -2.9  305  36 19   7.6   4.2 | -18.0  -0.4  310  39 20   6.6   3.6
 20000 -17.2   1.0  305  37 19   7.6   4.2 | -16.0   3.2  310  41 21   6.7   3.6
 19500 -16.0   3.2  310  38 19   7.6   4.2 | -15.0   5.0  310  43 22   6.7   3.7
 19000 -14.9   5.2  310  38 20   7.6   4.1 | -14.0   6.8  310  44 23   6.7   3.7
 18500 -13.8   7.2  310  39 20   7.0   3.8 | -13.1   8.4  310  45 23   6.2   3.4
 18000 -12.8   9.0  305  40 21   7.0   3.9 | -12.2  10.0  310  47 24   6.2   3.4
 17500 -11.7  10.9  305  41 21   6.7   3.7 | -11.2  11.8  310  48 25   6.0   3.3
 17000 -10.8  12.6  305  41 21   6.5   3.6 | -10.4  13.3  305  49 25   5.9   3.2
 16500  -9.8  14.4  305  42 22   6.6   3.6 |  -9.5  14.9  305  50 26   5.8   3.2
 16000  -8.8  16.2  305  42 22   6.9   3.8 |  -8.7  16.3  305  50 26   5.4   3.0
 15500  -7.2  19.0  305  43 22   6.6   3.6 |  -7.9  17.8  305  51 26   5.4   3.0
 15000  -6.3  20.7  305  43 22   6.2   3.4 |  -6.7  19.9  300  51 26   5.4   3.0
 14500  -5.4  22.3  305  44 22   6.3   3.4 |  -5.9  21.4  300  51 26   5.4   3.0
 14000  -4.5  23.9  305  44 22   6.7   3.7 |  -5.0  23.0  300  50 26   5.7   3.1
 13500  -3.5  25.7  300  43 22   6.7   3.7 |  -4.2  24.4  300  49 25   5.6   3.1
 13000  -2.5  27.5  300  42 22   7.2   4.0 |  -3.3  26.1  300  47 24   7.1   3.9
 12500  -1.4  29.5  300  42 21   7.2   3.9 |  -2.2  28.0  300  46 24   6.9   3.8
 12000  -0.3  31.5  300  41 21   7.9   4.3 |  -1.2  29.8  300  44 22   7.1   3.9
 11500   0.9  33.6  300  39 20   7.8   4.3 |  -0.1  31.8  300  41 21   7.0   3.9
 11000   2.1  35.8  300  38 19   8.4   4.6 |   0.9  33.6  300  38 20   7.4   4.1
 10500   3.3  37.9  300  35 18   8.3   4.6 |   2.0  35.6  295  35 18   8.1   4.5
 10250   3.8  38.8  295  34 18   4.4   2.4 |   2.6  36.7  295  34 17   3.8   2.1
 10000   4.1  39.4  295  34 17   6.0   3.3 |   2.7  36.9  295  33 17   4.8   2.6
  9750   4.8  40.6  295  32 17  10.1   5.6 |   3.4  38.1  295  30 16   9.6   5.3
  9500   5.5  41.9  295  31 16   8.8   4.8 |   4.0  39.2  290  28 14   8.4   4.6
  9250   6.1  43.0  295  30 15   6.1   3.3 |   4.6  40.3  290  26 13   6.7   3.7
  9000   6.5  43.7  290  29 15   6.0   3.3 |   5.0  41.0  285  23 12   7.2   3.9
  8750   7.0  44.6  290  27 14   8.0   4.4 |   5.7  42.3  280  21 11   9.4   5.2
  8500   7.6  45.7  285  25 13   7.8   4.3 |   6.4  43.5  275  18  9   8.9   4.9
  8250   8.2  46.8  280  23 12   8.1   4.4 |   7.0  44.6  265  16  8   8.4   4.6
  8000   8.8  47.8  275  21 11   8.2   4.5 |   7.6  45.7  260  15  8   8.7   4.8
  7750   9.4  48.9  265  19 10   8.2   4.5 |   8.3  46.9  250  14  7  10.3   5.7
  7500  10.0  50.0  260  18  9   8.8   4.8 |   9.1  48.4  245  13  7  10.2   5.6
  7250  10.7  51.3  255  17  9   9.2   5.0 |   9.8  49.6  240  13  7   9.4   5.1
  7000  11.4  52.5  250  16  8   9.6   5.3 |  10.5  50.9  240  13  7   9.7   5.3
  6750  12.1  53.8  245  16  8   9.0   4.9 |  11.3  52.3  235  13  6   9.1   5.0
  6500  12.7  54.9  240  16  8   6.3   3.5 |  11.9  53.4  235  12  6   8.0   4.4
  6250  12.9  55.2  240  15  8   1.4   0.8 |  12.4  54.3  230  12  6   4.3   2.4
  6000  13.2  55.8  235  15  8  13.5   7.4 |  12.8  55.0  230  12  6  15.1   8.3
  5750  14.4  57.9  230  16  8   0.3   0.2 |  14.0  57.2  230  13  7   1.4   0.7
  5500  12.1  53.8  225  10  5 -54.7 -30.0 |  11.9  53.4  215   9  5 -52.6 -28.8
________________________________________________________________________________

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.