Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
000
UXUS97 KBOU 250023
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1723 MST Monday, November 24, 2014

This forecast is for Tuesday, November 25, 2014:

If the trigger temperature of 41.4 F/5.2 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 785 ft/min (4.0 m/s)
   Maximum height of thermals.................. 15621 ft MSL (10334 ft AGL)

Forecast maximum temperature................... 51.0 F/11.0 C
Time of trigger temperature.................... 1000 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Overcast thin high
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 10412 ft MSL (5124 ft AGL)
Thermal soaring outlook for Wednesday 11/26.... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1700 MST)................ Weak NVA
Potential height of wave....................... 33569 ft MSL (28282 ft AGL)
Wave soaring outlook for Wednesday 11/26....... Fair

Remarks...

Sunrise/Sunset.................... 06:55:19 / 16:37:40 MST
Total possible sunshine........... 9 hr 42 min 21 sec (582 min 21 sec)
Altitude of sun at 11:46:39 MST... 29.45 degrees

Upper air data from numerical model forecast valid on 11/25/2014 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 15495 ft MSL (10208 ft AGL)
Lifted condensation level....... 15703 ft MSL (10415 ft AGL)
Lifted index.................... +5.3
K index......................... +2.6

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  -57.7 -71.9   330   34   17   1.1   0.6      M     M       M      M    M
 45000  -56.0 -68.8   340   57   29   1.1   0.6      M     M       M      M    M
 40000  -56.4 -69.5   345   75   39  -0.5  -0.3      M     M       M      M    M
 38000  -56.7 -70.1   350   84   43  -0.2  -0.1      M     M       M      M    M
 36000  -56.9 -70.4   355  102   52  -0.3  -0.1      M     M       M      M    M
 34000  -57.0 -70.6   360  120   62  -0.8  -0.4      M     M       M      M    M
 32000  -53.9 -65.0   360  121   62   6.3   3.5      M     M       M      M    M
 30000  -49.6 -57.3   355  118   61   7.0   3.8   26.8  80.2    12.1      M    M
 29000  -47.4 -53.3   355  111   57   7.4   4.0   25.7  78.2    11.4      M    M
 28000  -45.2 -49.4   350  104   54   7.4   4.0   24.7  76.4    10.8      M    M
 27000  -43.0 -45.4   350   97   50   7.4   4.0   23.9  75.0    10.3      M    M
 26000  -40.9 -41.6   345   89   46   7.0   3.9   22.9  73.2     9.6      M    M
 25000  -38.8 -37.8   345   80   41   7.0   3.9   21.8  71.2     8.9      M    M
 24000  -36.7 -34.1   345   71   36   7.0   3.9   20.8  69.5     8.2      M    M
 23000  -34.5 -30.1   340   63   32   7.3   4.0   19.9  67.8     7.5      M    M
 22000  -32.3 -26.1   340   56   29   7.3   4.0   18.9  66.1     6.9      M    M
 21000  -30.2 -22.4   335   49   25   7.3   4.0   18.1  64.6     6.2      M    M
 20000  -28.1 -18.6   335   46   24   6.6   3.6   17.0  62.6     5.4      M    M
 19500  -27.2 -17.0   335   45   23   6.6   3.6   16.4  61.6     4.9      M    M
 19000  -26.2 -15.2   335   44   22   6.7   3.7   15.9  60.6     4.5      M    M
 18500  -25.2 -13.4   335   43   22   7.0   3.8   15.4  59.7     4.1      M    M
 18000  -24.4 -11.9   330   41   21   4.1   2.2   14.7  58.4     3.5      M    M
 17500  -23.7 -10.7   330   39   20   4.3   2.4   13.7  56.7     2.7      M    M
 17000  -23.1  -9.6   330   37   19   5.0   2.7   12.9  55.1     1.9      M    M
 16500  -22.3  -8.1   325   35   18   5.3   2.9   12.1  53.8     1.2      M    M
 16000  -21.5  -6.7   325   32   16   5.5   3.0   11.3  52.4     0.6      M    M
 15500  -20.6  -5.1   325   30   15   6.0   3.3   10.7  51.2    -0.0    884  4.5
 15000  -19.2  -2.6   325   27   14   7.4   4.0    9.8  49.6    -0.8    821  4.2
 14500  -18.0  -0.4   330   26   13   8.0   4.4    9.5  49.1    -1.1    770  3.9
 14000  -16.8   1.8   330   24   12   8.3   4.6    9.2  48.6    -1.4    720  3.7
 13500  -15.5   4.1   335   24   12   8.6   4.7    9.0  48.2    -1.6    666  3.4
 13000  -14.2   6.4   335   24   12   8.8   4.8    8.8  47.9    -1.7    613  3.1
 12500  -12.9   8.8   335   25   13   9.0   4.9    8.7  47.6    -1.9    558  2.8
 12000  -11.6  11.1   335   26   13   9.0   4.9    8.6  47.4    -2.0    504  2.6
 11500  -10.2  13.6   335   29   15   9.0   4.9    8.5  47.2    -2.1    449  2.3
 11000   -8.9  16.0   330   32   16   7.1   3.9    8.3  47.0    -2.3    394  2.0
 10500   -8.1  17.4   325   33   17   5.8   3.2    7.6  45.8    -2.9    355  1.8
 10250   -7.7  18.1   325   33   17   5.0   2.8    7.3  45.2    -3.3    335  1.7
 10000   -7.4  18.7   320   33   17   2.5   1.4    6.9  44.4    -3.7    319  1.6
  9750   -7.2  19.0   320   34   17   2.7   1.5    6.2  43.2    -4.3    307  1.6
  9500   -6.9  19.6   315   34   18   4.5   2.5    5.8  42.4    -4.8    291  1.5
  9250   -6.6  20.1   315   35   18   2.9   1.6    5.3  41.6    -5.2    274  1.4
  9000   -6.5  20.3   310   35   18   0.9   0.5    4.7  40.5    -5.8    263  1.3
  8750   -6.5  20.3   305   34   18   0.5   0.3    4.0  39.2    -6.5    255  1.3
  8500   -6.4  20.5   300   33   17   0.3   0.1    3.3  37.9    -7.2    246  1.3
  8250   -6.4  20.5   295   32   17   3.1   1.7    2.6  36.7    -7.9    236  1.2
  8000   -6.0  21.2   290   30   15   5.3   2.9    2.2  36.0    -8.3    218  1.1
  7750   -5.6  21.9   290   28   14   5.3   2.9    1.9  35.3    -8.7    200  1.0
  7500   -5.2  22.6   285   25   13   6.6   3.6    1.6  34.8    -9.0    179  0.9
  7250   -4.7  23.5   285   23   12   7.0   3.9    1.3  34.4    -9.2    156  0.8
  7000   -4.1  24.6   280   20   10   7.0   3.9    1.1  34.0    -9.5    133  0.7
  6750   -3.6  25.5   275   18    9   7.4   4.1    0.9  33.7    -9.7    110  0.6
  6500   -3.1  26.4   270   16    8   6.7   3.7    0.8  33.4    -9.9     86  0.4
  6250   -2.6  27.3   265   14    7   7.6   4.2    0.5  32.9   -10.2     64  0.3
  6000   -2.1  28.2   255   13    7   2.4   1.3    0.3  32.5   -10.4     42  0.2
  5750   -2.4  27.7   245   11    6 -10.1  -5.6   -0.8  30.6   -11.5     45  0.2
  5500   -3.5  25.7   230    8    4 -14.6  -8.0   -2.5  27.6   -13.3     69  0.4

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

           11/25/2014 at 0800 MST          |       11/25/2014 at 1100 MST
                                           |
K index... +9.3  LI... +4.5                | K index... +13.7  LI... +2.7
CAPE... 0.0  CIN... -0.8                   | 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 -57.3 -71.1  330  33 17   1.5   0.8 | -58.8 -73.8  340  23 12   0.4   0.2
 45000 -55.0 -67.0  330  51 26   1.4   0.8 | -58.2 -72.8  330  36 18   0.4   0.2
 40000 -57.7 -71.9  350  81 42  -2.2  -1.2 | -59.9 -75.8  350  88 45  -1.2  -0.7
 38000 -58.7 -73.7  350  94 48   0.5   0.3 | -60.0 -76.0  350 104 54   2.0   1.1
 36000 -58.4 -73.1  355 104 53   0.4   0.2 | -58.8 -73.8  350 107 55   2.0   1.1
 34000 -58.2 -72.8  355 114 59   0.1   0.0 | -57.5 -71.5  350 110 57   5.8   3.2
 32000 -54.0 -65.2  350 113 58   7.8   4.3 | -52.4 -62.3  345 102 53   8.5   4.6
 30000 -48.7 -55.7  350 110 57   8.8   4.8 | -47.4 -53.3  340  94 49   8.8   4.9
 29000 -46.0 -50.8  350 106 55   8.8   4.8 | -44.7 -48.5  345  91 47   8.8   4.8
 28000 -43.4 -46.1  350 103 53   8.8   4.8 | -41.5 -42.7  345  87 45   8.8   4.8
 27000 -40.7 -41.3  350  99 51   9.0   4.9 | -38.8 -37.8  345  84 43   8.6   4.7
 26000 -38.5 -37.3  350  91 47   6.9   3.8 | -36.5 -33.7  345  82 42   7.8   4.3
 25000 -36.4 -33.5  345  81 42   7.0   3.8 | -34.2 -29.6  345  80 41   7.8   4.3
 24000 -34.3 -29.7  340  72 37   6.9   3.8 | -31.9 -25.4  345  79 40   7.8   4.3
 23000 -32.1 -25.8  340  66 34   7.7   4.2 | -29.6 -21.3  340  71 36   7.6   4.2
 22000 -29.8 -21.6  340  62 32   7.7   4.2 | -27.3 -17.1  335  62 32   7.7   4.2
 21000 -27.5 -17.5  335  58 30   7.7   4.2 | -25.0 -13.0  325  53 27   7.3   4.0
 20000 -25.4 -13.7  335  56 29   7.2   3.9 | -23.1  -9.6  330  55 28   6.7   3.7
 19500 -24.3 -11.7  335  56 29   7.2   3.9 | -22.1  -7.8  330  55 29   6.7   3.7
 19000 -23.2  -9.8  335  55 28   7.2   3.9 | -21.1  -6.0  330  56 29   6.7   3.7
 18500 -22.2  -8.0  335  54 28   7.3   4.0 | -20.1  -4.2  330  57 29   6.6   3.6
 18000 -21.2  -6.2  335  53 27   5.6   3.1 | -19.2  -2.6  330  57 29   6.2   3.4
 17500 -20.4  -4.7  330  50 26   5.8   3.2 | -18.3  -0.9  335  57 29   6.1   3.4
 17000 -19.5  -3.1  330  48 24   5.9   3.2 | -17.4   0.7  335  56 29   6.7   3.7
 16500 -18.6  -1.5  330  45 23   5.9   3.2 | -16.4   2.5  335  55 28   6.8   3.7
 16000 -17.8  -0.0  330  42 22   6.1   3.3 | -15.4   4.3  335  54 28   7.4   4.1
 15500 -16.3   2.7  330  39 20   6.4   3.5 | -14.2   6.4  335  54 28   8.1   4.5
 15000 -15.4   4.3  330  37 19   6.9   3.8 | -13.0   8.6  335  54 28   8.2   4.5
 14500 -14.3   6.3  330  35 18   7.2   3.9 | -11.7  10.9  335  55 28   8.7   4.8
 14000 -13.2   8.2  335  34 17   7.3   4.0 |  -9.8  14.4  335  56 29   8.2   4.5
 13500 -12.1  10.2  335  32 16   7.5   4.1 |  -8.6  16.5  335  56 29   7.8   4.3
 13000 -11.0  12.2  330  29 15   8.2   4.5 |  -7.4  18.7  335  57 29   7.8   4.3
 12500  -9.6  14.7  330  29 15   9.5   5.2 |  -6.3  20.7  335  57 29   7.7   4.2
 12000  -8.1  17.4  330  28 14   8.6   4.7 |  -5.1  22.8  330  57 29   6.8   3.7
 11500  -7.0  19.4  325  30 16   6.7   3.7 |  -4.3  24.3  330  55 29   5.0   2.7
 11000  -6.0  21.2  320  33 17   5.7   3.1 |  -3.6  25.5  330  54 28   4.5   2.5
 10500  -5.4  22.3  315  35 18   4.0   2.2 |  -3.0  26.6  325  53 27   3.5   1.9
 10250  -5.1  22.8  310  36 19   4.7   2.6 |  -2.7  27.1  320  52 27   4.2   2.3
 10000  -4.8  23.4  310  38 19   1.2   0.7 |  -2.4  27.7  320  52 27   1.6   0.9
  9750  -4.8  23.4  310  38 20  -0.5  -0.3 |  -2.5  27.5  315  51 26  -1.2  -0.7
  9500  -4.8  23.4  305  39 20   1.6   0.9 |  -2.5  27.5  315  50 26  -0.6  -0.3
  9250  -4.7  23.5  300  40 21   0.9   0.5 |  -2.6  27.3  310  49 25  -0.8  -0.5
  9000  -4.6  23.7  295  41 21   0.0   0.0 |  -2.7  27.1  305  48 25  -2.4  -1.3
  8750  -4.6  23.7  295  40 20  -0.1  -0.0 |  -2.9  26.8  300  45 23  -3.0  -1.6
  8500  -4.6  23.7  290  38 19  -0.1  -0.1 |  -3.1  26.4  300  41 21  -3.0  -1.7
  8250  -4.6  23.7  285  36 19   1.4   0.8 |  -3.3  26.1  295  38 20  -0.8  -0.4
  8000  -4.4  24.1  285  33 17   3.3   1.8 |  -3.2  26.2  290  34 18   3.3   1.8
  7750  -4.1  24.6  280  30 15   4.2   2.3 |  -2.8  27.0  290  30 16   5.1   2.8
  7500  -3.7  25.3  275  27 14   5.3   2.9 |  -2.4  27.7  290  27 14   5.7   3.1
  7250  -3.3  26.1  275  24 12   5.8   3.2 |  -2.0  28.4  285  24 13   6.9   3.8
  7000  -2.9  26.8  270  22 11   5.9   3.2 |  -1.4  29.5  285  22 11   8.0   4.4
  6750  -2.4  27.7  265  19 10   7.3   4.0 |  -0.8  30.6  285  19 10   7.3   4.0
  6500  -1.9  28.6  260  17  9   4.1   2.2 |  -0.3  31.5  280  17  9   7.7   4.2
  6250  -1.9  28.6  250  15  8  -0.1  -0.1 |   0.3  32.5  280  15  8   8.4   4.6
  6000  -1.8  28.8  240  14  7   1.8   1.0 |   1.0  33.8  275  12  6   8.3   4.6
  5750  -1.7  28.9  225  13  7  -0.4  -0.2 |   1.6  34.9  270  10  5   7.9   4.3
  5500  -2.1  28.2  215  12  6  -8.3  -4.6 |   2.1  35.8  265   9  4   8.7   4.8

           11/25/2014 at 1400 MST          |       11/25/2014 at 1700 MST
                                           |
K index... +11.8  LI... +3.5               | K index... +13.8  LI... +1.7
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.5
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -59.4 -74.9  305  22 11   0.2   0.1 | -59.8 -75.6  315  31 16  -1.3  -0.7
 45000 -59.1 -74.4  300  37 19   0.2   0.1 | -61.8 -79.2  325  60 31  -1.4  -0.8
 40000 -61.0 -77.8  345  89 46  -1.4  -0.8 | -62.4 -80.3  340  99 51  -0.3  -0.2
 38000 -60.7 -77.3  345 105 54   3.7   2.0 | -61.3 -78.3  340 105 54   4.9   2.7
 36000 -58.5 -73.3  345 103 53   3.7   2.0 | -58.4 -73.1  330  95 49   4.9   2.7
 34000 -56.2 -69.2  340 101 52   6.9   3.8 | -55.3 -67.5  325  88 45   8.3   4.5
 32000 -51.3 -60.3  335  93 48   8.1   4.5 | -50.2 -58.4  325  82 42   8.5   4.7
 30000 -46.4 -51.5  325  87 45   8.9   4.9 | -44.5 -48.1  330  78 40   7.9   4.3
 29000 -43.2 -45.8  330  82 42   8.8   4.8 | -42.1 -43.8  335  80 41   7.9   4.3
 28000 -40.5 -40.9  330  78 40   8.8   4.8 | -39.8 -39.6  335  81 42   7.9   4.3
 27000 -37.9 -36.2  330  74 38   8.3   4.5 | -37.4 -35.3  335  84 43   7.8   4.3
 26000 -35.8 -32.4  335  73 38   7.0   3.8 | -35.1 -31.2  335  82 42   7.6   4.2
 25000 -33.7 -28.7  340  74 38   7.0   3.8 | -32.9 -27.2  335  80 41   7.6   4.2
 24000 -31.6 -24.9  345  75 39   7.0   3.8 | -30.6 -23.1  335  78 40   7.6   4.1
 23000 -29.4 -20.9  345  72 37   7.2   4.0 | -28.4 -19.1  335  77 40   7.2   4.0
 22000 -27.3 -17.1  340  68 35   7.2   4.0 | -26.3 -15.3  335  75 39   7.2   4.0
 21000 -25.1 -13.2  340  64 33   7.8   4.3 | -24.2 -11.6  335  74 38   7.0   3.9
 20000 -22.6  -8.7  335  62 32   8.5   4.7 | -22.1  -7.8  335  70 36   6.8   3.8
 19500 -21.3  -6.3  335  61 31   8.5   4.7 | -21.1  -6.0  335  68 35   6.8   3.8
 19000 -20.1  -4.2  335  60 31   8.5   4.7 | -20.1  -4.2  340  66 34   6.9   3.8
 18500 -18.8  -1.8  335  59 30   8.2   4.5 | -19.1  -2.4  340  64 33   6.9   3.8
 18000 -17.7   0.1  335  58 30   7.2   3.9 | -18.0  -0.4  335  62 32   7.1   3.9
 17500 -16.6   2.1  335  58 30   7.3   4.0 | -17.0   1.4  335  59 31   7.0   3.8
 17000 -15.6   3.9  335  58 30   6.3   3.4 | -15.9   3.4  335  56 29   8.1   4.5
 16500 -14.7   5.5  340  61 31   6.2   3.4 | -14.7   5.5  335  53 27   8.1   4.4
 16000 -13.8   7.2  340  63 32   6.4   3.5 | -13.5   7.7  335  50 26   7.9   4.3
 15500 -12.8   9.0  340  62 32   6.6   3.6 | -12.3   9.9  335  51 26   7.8   4.3
 15000 -11.8  10.8  340  60 31   6.6   3.6 | -10.6  12.9  335  53 27   8.1   4.4
 14500 -10.4  13.3  340  60 31   6.5   3.6 |  -9.4  15.1  335  54 28   8.1   4.5
 14000  -9.4  15.1  340  60 31   6.8   3.7 |  -8.2  17.2  335  55 28   8.3   4.5
 13500  -8.4  16.9  340  59 30   7.1   3.9 |  -6.9  19.6  330  57 29   8.3   4.5
 13000  -7.4  18.7  340  58 30   7.6   4.2 |  -5.7  21.7  330  58 30   7.7   4.2
 12500  -6.1  21.0  340  57 29   8.3   4.6 |  -4.6  23.7  330  58 30   7.1   3.9
 12000  -4.9  23.2  340  56 29   7.8   4.3 |  -3.6  25.5  325  59 30   6.7   3.7
 11500  -3.8  25.2  340  55 28   6.8   3.7 |  -2.7  27.1  325  59 31   6.1   3.4
 11000  -2.8  27.0  335  55 28   6.0   3.3 |  -1.8  28.8  325  60 31   5.6   3.1
 10500  -2.1  28.2  335  53 27   4.7   2.6 |  -1.0  30.2  320  58 30   5.3   2.9
 10250  -1.7  28.9  330  53 27   5.1   2.8 |  -0.7  30.7  320  57 30   4.0   2.2
 10000  -1.3  29.7  330  52 27   4.0   2.2 |  -0.5  31.1  320  57 29   2.8   1.5
  9750  -1.1  30.0  325  51 26   2.0   1.1 |  -0.2  31.6  320  56 29   3.1   1.7
  9500  -1.0  30.2  325  50 26   1.8   1.0 |  -0.0  32.0  315  54 28   3.1   1.7
  9250  -0.9  30.4  320  50 26   2.2   1.2 |   0.2  32.4  315  53 27   2.9   1.6
  9000  -0.7  30.7  315  49 25   1.3   0.7 |   0.4  32.7  310  51 26   1.4   0.8
  8750  -0.7  30.7  315  46 24  -1.1  -0.6 |   0.4  32.7  310  48 25   0.4   0.2
  8500  -0.9  30.4  310  43 22  -2.5  -1.4 |   0.5  32.9  310  45 23   0.2   0.1
  8250  -1.0  30.2  305  41 21  -0.3  -0.1 |   0.5  32.9  305  42 22   1.2   0.6
  8000  -0.9  30.4  305  37 19   3.4   1.9 |   0.7  33.3  305  38 20   2.7   1.5
  7750  -0.5  31.1  305  33 17   5.0   2.8 |   0.9  33.6  305  35 18   3.2   1.7
  7500  -0.1  31.8  300  29 15   5.2   2.9 |   1.1  34.0  305  31 16   3.4   1.9
  7250   0.3  32.5  300  26 14   7.1   3.9 |   1.5  34.7  300  28 14   5.5   3.0
  7000   0.9  33.6  300  24 12   8.7   4.8 |   2.0  35.6  300  25 13   7.5   4.1
  6750   1.5  34.7  300  21 11   8.7   4.7 |   2.5  36.5  300  22 11   5.3   2.9
  6500   2.2  36.0  300  19 10   9.5   5.2 |   2.8  37.0  300  19 10   5.7   3.1
  6250   3.0  37.4  300  18  9   9.8   5.4 |   3.4  38.1  300  16  8   7.8   4.3
  6000   3.7  38.7  300  16  8   9.9   5.4 |   3.9  39.0  300  13  7   8.1   4.4
  5750   4.4  39.9  300  14  7   9.8   5.4 |   4.5  40.1  300  11  6   6.2   3.4
  5500   5.2  41.4  300  13  6  10.0   5.5 |   4.8  40.6  295   8  4   0.9   0.5
________________________________________________________________________________

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



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.