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 261258
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0657 MDT Thursday, March 26, 2015

This forecast is for Thursday, March 26, 2015:

If the trigger temperature of 47.6 F/8.7 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 646 ft/min (3.3 m/s)
   Maximum height of thermals.................. 15408 ft MSL (10123 ft AGL)

Forecast maximum temperature................... 58.0 F/14.9 C
Time of trigger temperature.................... 1100 MDT
Time of overdevelopment........................ 1400 MDT
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 11209 ft MSL (5924 ft AGL)
Thermal soaring outlook for Friday 03/27....... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... 17838 ft MSL (12553 ft AGL)
Weak PVA/NVA (through 1800 MDT)................ Weak NVA
Potential height of wave....................... 28176 ft MSL (22891 ft AGL)
Wave soaring outlook for Friday 03/27.......... Poor

Remarks...

Sunrise/Sunset.................... 06:53:31 / 19:16:23 MDT
Total possible sunshine........... 12 hr 22 min 52 sec (742 min 52 sec)
Altitude of sun at 13:05:07 MDT... 52.55 degrees

Upper air data from rawinsonde observation taken on 03/26/2015 at 0600 MDT

Freezing level.................. 5294 ft MSL (9 ft AGL)
Additional freezing level....... 7874 ft MSL (2589 ft AGL)
Convective condensation level... 15109 ft MSL (9824 ft AGL)
Lifted condensation level....... 15395 ft MSL (10109 ft AGL)
Lifted index.................... +3.3
K index......................... +10.2

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  -55.3 -67.5   355   23   12   6.3   3.5  109.9 229.8    54.3      M    M
 45000  -55.8 -68.4   350   48   25   3.7   2.0   82.8 181.1    41.8      M    M
 40000  -55.1 -67.2   345   53   27   6.6   3.6   60.8 141.5    30.3      M    M
 38000  -54.7 -66.5   345   58   30 -12.3  -6.7   52.7 126.9    25.7      M    M
 36000  -55.8 -68.4   345   65   33   2.8   1.6   42.4 108.4    19.3      M    M
 34000  -54.1 -65.4   345   68   35   3.3   1.8   36.5  97.8    15.6      M    M
 32000  -51.6 -60.9   360   65   33   5.1   2.8   31.7  89.0    12.5      M    M
 30000  -48.2 -54.8   360   74   38   7.1   3.9   27.5  81.5     9.8      M    M
 29000  -46.6 -51.9   360   79   41   4.1   2.3   25.7  78.3     8.5      M    M
 28000  -44.1 -47.4   360   84   43   8.5   4.7   25.2  77.4     8.2      M    M
 27000  -41.5 -42.7   355   77   40   8.6   4.7   24.6  76.3     7.9      M    M
 26000  -39.0 -38.2   355   72   37   8.6   4.7   24.2  75.5     7.6      M    M
 25000  -36.4 -33.5   350   66   34   8.6   4.7   23.8  74.9     7.5      M    M
 24000  -33.9 -29.0   360   63   33   8.5   4.7   23.3  74.0     7.1      M    M
 23000  -31.2 -24.2   360   63   32   9.0   4.9   22.9  73.2     6.9      M    M
 22000  -28.5 -19.3   360   62   32   9.0   4.9   22.6  72.6     6.7      M    M
 21000  -25.8 -14.4   355   61   32   9.0   4.9   22.4  72.3     6.6      M    M
 20000  -23.2  -9.8   355   61   31   9.0   4.9   22.3  72.1     6.6      M    M
 19500  -21.8  -7.2   350   60   31   8.9   4.9   22.1  71.8     6.5      M    M
 19000  -20.5  -4.9   350   59   30   8.6   4.7   21.9  71.5     6.4      M    M
 18500  -19.4  -2.9   345   58   30   5.6   3.1   21.5  70.7     6.0      M    M
 18000  -19.0  -2.2   345   56   29   0.4   0.2   20.3  68.5     5.0      M    M
 17500  -20.1  -4.2   345   55   28  -5.5  -3.0   17.4  63.2     2.5      M    M
 17000  -19.2  -2.6   340   53   27   8.4   4.6   16.7  62.1     1.9      M    M
 16500  -18.0  -0.4   340   51   26   6.1   3.3   16.5  61.6     1.7      M    M
 16000  -17.4   0.7   340   49   25   5.6   3.1   15.6  60.1     0.8      M    M
 15500  -16.5   2.3   340   47   24   6.1   3.3   15.0  58.9     0.2      M    M
 15000  -15.1   4.8   340   42   22   7.5   4.1   14.1  57.4    -0.5    800  4.1
 14500  -13.9   7.0   340   39   20   7.9   4.4   13.8  56.9    -0.8    749  3.8
 14000  -12.7   9.1   340   37   19   8.0   4.4   13.5  56.4    -1.1    699  3.5
 13500  -11.5  11.3   335   37   19   8.0   4.4   13.2  55.8    -1.4    648  3.3
 13000  -10.3  13.5   335   36   19   8.0   4.4   12.9  55.2    -1.7    598  3.0
 12500   -9.1  15.6   330   36   19   7.9   4.4   12.6  54.7    -1.9    547  2.8
 12000   -7.9  17.8   330   35   18   7.5   4.1   12.4  54.3    -2.2    497  2.5
 11500   -6.9  19.6   330   29   15   6.1   3.4   11.8  53.3    -2.7    453  2.3
 11000   -6.0  21.2   325   23   12   6.2   3.4   11.2  52.2    -3.3    410  2.1
 10500   -5.1  22.8   325   18    9   6.3   3.5   10.7  51.2    -3.8    368  1.9
 10250   -4.6  23.7   320   15    8   5.7   3.1   10.4  50.8    -4.1    347  1.8
 10000   -4.3  24.3   320   13    7   4.8   2.6   10.1  50.1    -4.5    328  1.7
  9750   -3.9  25.0   320   15    8   4.7   2.6    9.7  49.4    -4.9    310  1.6
  9500   -3.6  25.5   315   17    9   4.7   2.6    9.3  48.7    -5.3    292  1.5
  9250   -3.2  26.2   315   19   10   4.5   2.5    8.9  47.9    -5.6    274  1.4
  9000   -2.8  27.0   315   21   11   6.9   3.8    8.5  47.3    -6.0    255  1.3
  8750   -2.2  28.0   310   23   12   8.8   4.9    8.4  47.1    -6.1    229  1.2
  8500   -1.6  29.1   305   24   13   8.3   4.6    8.3  47.0    -6.2    203  1.0
  8250   -0.9  30.4   305   26   13   8.5   4.6    8.2  46.8    -6.3    176  0.9
  8000   -0.3  31.5   300   28   14   8.4   4.6    8.1  46.6    -6.5    150  0.8
  7750    0.3  32.5   300   29   15   8.4   4.6    8.0  46.4    -6.6    124  0.6
  7500    0.9  33.6   300   29   15   8.4   4.6    7.9  46.2    -6.7     98  0.5
  7250    1.6  34.9   300   29   15   8.5   4.6    7.8  46.1    -6.8     72  0.4
  7000    2.2  36.0   300   30   15   8.4   4.6    7.7  45.9    -7.0     46  0.2
  6750    2.8  37.0   300   28   14   8.7   4.7    7.6  45.7    -7.1     19  0.1
  6500    3.5  38.3   300   26   13   7.7   4.2    7.5  45.5    -7.2      M    M
  6250    4.0  39.2   305   23   12   6.6   3.6    7.3  45.1    -7.5      M    M
  6000    4.3  39.7   305   21   11   1.6   0.9    6.9  44.5    -7.9      M    M
  5750    4.0  39.2   300   14    7  -9.3  -5.1    5.9  42.6    -8.9      M    M
  5500    2.7  36.9   270    7    3 -23.9 -13.1    4.0  39.1   -11.0      M    M

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

           03/26/2015 at 0900 MDT          |       03/26/2015 at 1200 MDT
                                           |
K index... +12.6  LI... +278.0             | K index... +12.8  LI... +277.8
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -1.0
                                           |
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 -56.1 -69.0  350  43 22   1.8   1.0 | -56.5 -69.7  350  43 22   1.2   0.7
 45000 -53.4 -64.1  355  58 30   1.2   0.6 | -54.6 -66.3  355  60 31   1.1   0.6
 40000 -54.2 -65.6  350  67 34  -0.6  -0.3 | -53.5 -64.3  355  75 39   0.7   0.4
 38000 -54.4 -65.9  350  67 35   0.2   0.1 | -53.8 -64.8  355  77 40  -1.7  -1.0
 36000 -54.3 -65.7  355  63 33   0.2   0.1 | -54.8 -66.6  355  73 38  -1.7  -1.0
 34000 -53.8 -64.8  005  63 32   5.2   2.9 | -55.4 -67.7  355  71 37   5.6   3.1
 32000 -51.0 -59.8  015  90 47   4.6   2.6 | -52.0 -61.6  005  82 42   5.7   3.1
 30000 -47.9 -54.2  020 112 58   7.3   4.0 | -48.4 -55.1  015  92 47   8.7   4.8
 29000 -45.8 -50.4  015 103 53   7.1   3.9 | -45.9 -50.6  010  88 45   8.4   4.6
 28000 -43.7 -46.7  010  95 49   7.1   3.9 | -42.7 -44.9  005  83 43   8.4   4.6
 27000 -41.5 -42.7  005  88 45   7.4   4.1 | -40.2 -40.4  005  79 41   8.6   4.7
 26000 -39.1 -38.4  005  82 42   8.4   4.6 | -37.6 -35.7  360  79 41   8.8   4.8
 25000 -36.6 -33.9  360  78 40   8.4   4.6 | -35.0 -31.0  360  80 41   8.8   4.8
 24000 -34.1 -29.4  355  73 38   8.4   4.6 | -32.4 -26.3  360  80 41   8.4   4.6
 23000 -31.6 -24.9  355  69 36   8.3   4.5 | -30.0 -22.0  355  74 38   8.1   4.4
 22000 -29.1 -20.4  350  66 34   8.3   4.5 | -27.6 -17.7  355  69 35   8.1   4.4
 21000 -26.6 -15.9  350  62 32   8.3   4.5 | -25.2 -13.4  350  63 32   8.1   4.4
 20000 -24.2 -11.6  350  58 30   8.2   4.5 | -22.8  -9.0  345  58 30   8.1   4.4
 19500 -23.0  -9.4  345  56 29   8.3   4.5 | -21.6  -6.9  340  56 29   8.1   4.4
 19000 -21.7  -7.1  345  54 28   8.2   4.5 | -20.4  -4.7  340  54 28   8.1   4.5
 18500 -20.5  -4.9  345  52 27   7.7   4.2 | -19.2  -2.6  335  52 27   7.3   4.0
 18000 -19.5  -3.1  345  50 26   7.0   3.9 | -18.2  -0.8  340  51 26   7.0   3.8
 17500 -17.9  -0.2  345  47 24   6.9   3.8 | -17.2   1.0  340  50 26   6.7   3.7
 17000 -16.9   1.6  340  45 23   6.8   3.7 | -16.3   2.7  335  48 25   5.3   2.9
 16500 -15.9   3.4  340  43 22   6.6   3.6 | -15.5   4.1  335  45 23   5.4   3.0
 16000 -15.0   5.0  340  40 21   5.7   3.2 | -14.8   5.4  330  42 22   5.0   2.8
 15500 -14.1   6.6  340  38 20   5.9   3.2 | -14.0   6.8  330  38 20   5.0   2.7
 15000 -13.4   7.9  340  36 19   4.8   2.7 | -12.7   9.1  325  35 18   6.9   3.8
 14500 -12.6   9.3  340  35 18   4.9   2.7 | -11.7  10.9  325  34 18   6.7   3.7
 14000 -11.8  10.8  340  34 17   6.0   3.3 | -10.7  12.7  325  33 17   7.7   4.2
 13500 -10.9  12.4  340  31 16   6.1   3.3 |  -9.5  14.9  325  33 17   7.7   4.2
 13000 -10.0  14.0  340  30 15   6.2   3.4 |  -8.4  16.9  325  32 16   7.1   3.9
 12500  -9.1  15.6  345  30 16   6.1   3.3 |  -7.4  18.7  325  31 16   7.1   3.9
 12000  -8.1  17.4  350  31 16   7.6   4.2 |  -6.4  20.5  325  30 15   6.9   3.8
 11500  -6.9  19.6  350  31 16   7.9   4.4 |  -5.4  22.3  330  29 15   6.8   3.7
 11000  -5.8  21.6  350  30 16   7.2   4.0 |  -4.3  24.3  330  28 14   8.0   4.4
 10500  -4.7  23.5  350  29 15   7.7   4.2 |  -3.1  26.4  325  26 13   8.8   4.9
 10250  -4.2  24.4  350  28 14   4.7   2.6 |  -2.5  27.5  325  25 13   4.7   2.6
 10000  -4.0  24.8  350  28 14   4.7   2.6 |  -2.3  27.9  325  25 13   5.1   2.8
  9750  -3.4  25.9  350  26 14   9.4   5.1 |  -1.6  29.1  320  24 12   9.9   5.4
  9500  -2.7  27.1  345  25 13  10.3   5.7 |  -1.0  30.2  320  24 12   9.6   5.2
  9250  -1.9  28.6  345  23 12   7.9   4.4 |  -0.3  31.5  315  23 12   5.5   3.0
  9000  -1.5  29.3  340  22 11   6.1   3.4 |  -0.1  31.8  315  23 12   2.2   1.2
  8750  -0.9  30.4  335  21 11   8.5   4.7 |   0.1  32.2  310  23 12   3.4   1.9
  8500  -0.3  31.5  335  20 11   8.2   4.5 |   0.3  32.5  305  23 12   3.6   2.0
  8250   0.2  32.4  325  21 11   4.6   2.5 |   0.6  33.1  305  22 11   4.2   2.3
  8000   0.5  32.9  320  22 11   3.7   2.0 |   0.9  33.6  300  20 10   4.5   2.5
  7750   0.7  33.3  315  23 12   2.5   1.4 |   1.3  34.3  295  18  9   5.9   3.2
  7500   0.9  33.6  310  24 12   3.7   2.0 |   1.8  35.2  295  15  8   8.1   4.4
  7250   1.3  34.3  305  23 12   6.3   3.5 |   2.4  36.3  295  14  7   8.7   4.8
  7000   1.7  35.1  305  21 11   5.4   3.0 |   3.0  37.4  295  12  6   8.5   4.7
  6750   2.2  36.0  300  20 10   6.9   3.8 |   3.6  38.5  290  10  5   8.7   4.8
  6500   2.7  36.9  300  18  9   6.6   3.6 |   4.3  39.7  290  10  5   9.9   5.4
  6250   3.1  37.6  295  16  8   5.9   3.2 |   5.0  41.0  290   9  5  10.5   5.8
  6000   3.6  38.5  285  14  7   4.2   2.3 |   5.8  42.4  290   9  5  10.3   5.6
  5750   3.6  38.5  275  12  6  -0.8  -0.4 |   6.6  43.9  285   8  4  13.1   7.2
  5500   3.4  38.1  265   8  4  -2.4  -1.3 |   7.8  46.0  285   8  4  17.9   9.8

           03/26/2015 at 1500 MDT          |       03/26/2015 at 1800 MDT
                                           |
K index... +15.4  LI... +276.8             | K index... +20.0  LI... +276.5
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.6
                                           |
Height Temperature  Wnd WndSpd  Lapse Rate | Temperature  Wnd WndSpd  Lapse Rate
ft MSL deg C deg F  Dir kt m/s  C/km F/kft | deg C deg F  Dir kt m/s  C/km F/kft
--------------------------------------------------------------------------------
 50000 -56.5 -69.7  345  44 23   1.6   0.9 | -56.6 -69.9  345  48 25   2.2   1.2
 45000 -54.1 -65.4  355  61 32   0.9   0.5 | -53.3 -63.9  350  60 31  -0.8  -0.4
 40000 -55.0 -67.0  355  72 37  -0.6  -0.3 | -54.6 -66.3  350  74 38  -0.9  -0.5
 38000 -55.6 -68.1  355  75 39  -1.2  -0.6 | -55.4 -67.7  355  78 40  -1.7  -0.9
 36000 -56.3 -69.3  355  77 40  -1.2  -0.6 | -56.4 -69.5  355  83 42  -1.7  -0.9
 34000 -56.3 -69.3  355  78 40   8.0   4.4 | -56.5 -69.7  355  85 44   9.5   5.2
 32000 -52.1 -61.8  360  76 39   7.0   3.9 | -51.4 -60.5  355  82 42   8.5   4.7
 30000 -47.7 -53.9  005  75 39   8.9   4.9 | -45.7 -50.3  355  77 40   8.4   4.6
 29000 -44.4 -47.9  360  75 39   8.9   4.9 | -43.2 -45.8  355  75 39   8.4   4.6
 28000 -41.7 -43.1  360  76 39   8.9   4.9 | -40.7 -41.3  360  74 38   8.4   4.6
 27000 -39.1 -38.4  355  76 39   8.5   4.7 | -38.2 -36.8  360  73 37   8.8   4.9
 26000 -36.6 -33.9  355  74 38   8.5   4.7 | -35.5 -31.9  360  72 37   8.9   4.9
 25000 -34.0 -29.2  350  73 38   8.5   4.7 | -32.8 -27.0  360  71 37   8.9   4.9
 24000 -31.5 -24.7  350  72 37   8.8   4.9 | -30.2 -22.4  355  70 36   8.9   4.9
 23000 -28.8 -19.8  350  70 36   9.0   5.0 | -27.5 -17.5  355  68 35   8.8   4.8
 22000 -26.1 -15.0  345  68 35   9.1   5.0 | -24.9 -12.8  350  65 34   8.9   4.9
 21000 -23.5 -10.3  345  66 34   7.3   4.0 | -22.4  -8.3  345  63 33   7.0   3.8
 20000 -21.3  -6.3  345  64 33   7.5   4.1 | -20.3  -4.5  350  62 32   7.1   3.9
 19500 -20.2  -4.4  345  64 33   7.5   4.1 | -19.3  -2.7  350  61 31   7.1   3.9
 19000 -19.1  -2.4  340  63 32   7.5   4.1 | -18.2  -0.8  350  60 31   7.2   4.0
 18500 -18.0  -0.4  340  62 32   7.5   4.1 | -17.2   1.0  350  60 31   5.4   3.0
 18000 -16.9   1.6  340  60 31   7.5   4.1 | -16.5   2.3  350  59 30   5.0   2.7
 17500 -15.8   3.6  335  58 30   7.4   4.0 | -15.8   3.6  345  58 30   4.9   2.7
 17000 -14.7   5.5  335  56 29   6.9   3.8 | -15.1   4.8  345  56 29   4.9   2.7
 16500 -13.7   7.3  335  54 28   7.1   3.9 | -14.4   6.1  345  55 28   4.8   2.7
 16000 -12.8   9.0  335  51 26   5.0   2.7 | -13.2   8.2  345  51 26   5.8   3.2
 15500 -12.1  10.2  335  48 25   5.2   2.8 | -12.4   9.7  345  49 25   5.8   3.2
 15000 -11.2  11.8  340  45 23   2.5   1.4 | -11.6  11.1  345  47 24   5.3   2.9
 14500 -10.8  12.6  340  42 22   2.4   1.3 | -10.8  12.6  345  45 23   5.1   2.8
 14000 -10.2  13.6  340  40 21   6.3   3.5 |  -9.9  14.2  345  42 21   7.7   4.2
 13500  -9.3  15.3  340  38 19   5.9   3.2 |  -8.7  16.3  340  38 19   7.5   4.1
 13000  -8.4  16.9  340  36 19   6.5   3.6 |  -7.7  18.1  335  34 17   7.3   4.0
 12500  -7.5  18.5  340  35 18   6.5   3.6 |  -6.6  20.1  335  29 15   7.2   4.0
 12000  -6.5  20.3  340  33 17   6.7   3.7 |  -5.5  22.1  330  25 13   8.0   4.4
 11500  -5.5  22.1  335  29 15   6.6   3.6 |  -4.3  24.3  330  22 11   8.0   4.4
 11000  -4.4  24.1  330  25 13   8.2   4.5 |  -3.1  26.4  325  19 10   8.3   4.5
 10500  -3.2  26.2  330  22 11   9.2   5.0 |  -1.9  28.6  325  17  9   9.3   5.1
 10250  -2.6  27.3  325  20 11   3.9   2.2 |  -1.3  29.7  320  17  9   3.9   2.2
 10000  -2.5  27.5  325  20 10   5.1   2.8 |  -1.1  30.0  320  16  8   5.5   3.0
  9750  -1.7  28.9  320  18  9  11.3   6.2 |  -0.3  31.5  320  16  8  11.9   6.6
  9500  -1.0  30.2  320  17  9   9.7   5.3 |   0.5  32.9  315  15  8  10.6   5.8
  9250  -0.3  31.5  315  15  8   7.7   4.2 |   1.2  34.2  315  15  8   8.0   4.4
  9000   0.1  32.2  315  14  7   6.7   3.7 |   1.7  35.1  315  14  7   6.1   3.4
  8750   0.7  33.3  315  12  6   8.6   4.7 |   2.2  36.0  315  12  6   8.3   4.5
  8500   1.3  34.3  315  11  6   9.0   4.9 |   2.8  37.0  310  11  5   8.2   4.5
  8250   2.0  35.6  315  10  5   9.3   5.1 |   3.4  38.1  310   9  5   7.8   4.3
  8000   2.7  36.9  310  10  5   9.4   5.2 |   4.0  39.2  310   8  4   7.7   4.2
  7750   3.4  38.1  310   9  5  10.1   5.5 |   4.5  40.1  305   7  3   8.4   4.6
  7500   4.2  39.6  310   9  5  10.3   5.7 |   5.2  41.4  300   6  3   9.1   5.0
  7250   4.9  40.8  310   9  5  10.0   5.5 |   5.9  42.6  300   5  3   9.5   5.2
  7000   5.7  42.3  310   9  5  10.1   5.5 |   6.6  43.9  300   5  3   9.4   5.1
  6750   6.4  43.5  310   9  5  10.3   5.7 |   7.3  45.1  300   5  2  10.4   5.7
  6500   7.2  45.0  310   9  4  10.3   5.6 |   8.1  46.6  300   5  2  10.4   5.7
  6250   8.0  46.4  310   8  4  10.2   5.6 |   8.8  47.8  295   5  2   9.5   5.2
  6000   8.7  47.7  310   8  4  10.0   5.5 |   9.6  49.3  295   4  2  10.2   5.6
  5750   9.5  49.1  305   8  4  13.2   7.3 |  10.3  50.5  295   4  2  10.8   5.9
  5500  10.7  51.3  310   8  4  19.3  10.6 |  11.1  52.0  295   4  2  10.9   6.0
________________________________________________________________________________

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.