Soaring Guidance
Issued by NWS Denver/Boulder, CO

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12
000
UXUS97 KBOU 251321
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0621 MST Sunday, February 25, 2018

This forecast is for Sunday, February 25, 2018:

If the trigger temperature of 31.1 F/-0.5 C is reached...then
   Thermal Soaring Index....................... Good
   Maximum rate of lift........................ 722 ft/min (3.7 m/s)
   Maximum height of thermals.................. 13745 ft MSL (8460 ft AGL)

Forecast maximum temperature................... 37.0 F/3.2 C
Time of trigger temperature.................... 1030 MST
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 9997 ft MSL (4712 ft AGL)
Thermal soaring outlook for Monday 02/26....... Good

Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... Becoming fair after 1200
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1700 MST)................ Neither
Potential height of wave....................... 16377 ft MSL (11092 ft AGL)
Wave soaring outlook for Monday 02/26.......... Fair

Remarks...

Sunrise/Sunset.................... 06:38:00 / 17:46:58 MST
Total possible sunshine........... 11 hr 8 min 58 sec (668 min 58 sec)
Altitude of sun at 12:12:29 MST... 41.25 degrees

Upper air data from rawinsonde observation taken on 02/25/2018 at 0500 MST

Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 15074 ft MSL (9789 ft AGL)
Lifted condensation level....... 15015 ft MSL (9729 ft AGL)
Lifted index.................... +4.3
K index......................... -9.1

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  -57.6 -71.7   260   62   32   3.6   2.0  108.2 226.8    59.6      M    M
 45000  -52.3 -62.1   255   53   27   3.5   1.9   92.0 197.7    54.0      M    M
 40000  -52.0 -61.6   255   67   34   4.8   2.6   69.2 156.6    42.9      M    M
 38000  -49.3 -56.7   250   64   33   4.7   2.6   64.4 147.9    40.8      M    M
 36000  -47.9 -54.2   250   65   33   2.0   1.1   57.7 135.8    37.4      M    M
 34000  -47.5 -53.5   245   70   36  -6.6  -3.6   49.9 121.7    32.9      M    M
 32000  -50.3 -58.5   240   60   31  -1.9  -1.0   36.5  97.8    24.3      M    M
 30000  -50.1 -58.2   245   51   26   3.0   1.6   28.9  83.9    19.3      M    M
 29000  -49.3 -56.7   240   54   28   1.9   1.0   26.0  78.9    17.4      M    M
 28000  -48.8 -55.8   245   48   25   1.5   0.8   22.7  72.9    15.1      M    M
 27000  -48.0 -54.4   255   43   22   5.2   2.8   20.0  68.0    13.2      M    M
 26000  -46.5 -51.7   260   48   24   4.9   2.7   18.0  64.5    11.9      M    M
 25000  -45.1 -49.2   260   52   27   4.1   2.2   16.3  61.3    10.6      M    M
 24000  -45.5 -49.9   255   54   28 -10.7  -5.9   12.0  53.6     7.4      M    M
 23000  -44.6 -48.3   255   56   29   7.0   3.8    9.5  49.2     5.5      M    M
 22000  -44.2 -47.6   260   48   25   8.0   4.4    6.3  43.4     2.9      M    M
 21000  -41.7 -43.1   265   40   20   8.5   4.7    5.9  42.6     2.6      M    M
 20000  -39.1 -38.4   275   32   16   8.5   4.7    5.6  42.0     2.3      M    M
 19500  -37.8 -36.0   280   30   15   8.5   4.7    5.3  41.5     2.1      M    M
 19000  -36.6 -33.9   280   28   14   8.5   4.7    5.0  41.1     1.9      M    M
 18500  -35.3 -31.5   285   27   14   8.5   4.7    4.8  40.7     1.7      M    M
 18000  -34.0 -29.2   290   25   13   8.6   4.7    4.6  40.3     1.6      M    M
 17500  -32.8 -27.0   295   25   13   8.2   4.5    4.4  39.8     1.4      M    M
 17000  -31.5 -24.7   295   26   13   8.5   4.7    4.2  39.5     1.2      M    M
 16500  -29.6 -21.3   290   27   14   8.5   4.7    3.9  39.0     1.0      M    M
 16000  -28.3 -18.9   290   27   14   8.5   4.7    3.7  38.7     0.8      M    M
 15500  -27.0 -16.6   290   27   14   8.5   4.7    3.5  38.3     0.6      M    M
 15000  -25.8 -14.4   290   28   14   8.5   4.7    3.3  37.9     0.4      M    M
 14500  -24.5 -12.1   290   28   14   8.5   4.7    3.1  37.6     0.3      M    M
 14000  -23.2  -9.8   290   28   15   8.5   4.7    2.9  37.2     0.1      M    M
 13500  -21.9  -7.4   290   29   15   8.5   4.7    2.6  36.8    -0.2    687  3.5
 13000  -20.7  -5.3   285   30   16   8.5   4.7    2.4  36.3    -0.4    634  3.2
 12500  -19.4  -2.9   285   31   16   8.5   4.7    2.2  35.9    -0.6    581  3.0
 12000  -18.1  -0.6   285   32   16   8.4   4.6    2.0  35.6    -0.8    528  2.7
 11500  -16.8   1.8   280   32   16   7.3   4.0    1.8  35.2    -1.0    475  2.4
 11000  -16.0   3.2   280   32   16   5.3   2.9    1.1  33.9    -1.7    435  2.2
 10500  -15.2   4.6   280   28   14   5.4   3.0    0.4  32.6    -2.4    397  2.0
 10250  -14.8   5.4   280   25   13   5.0   2.7    0.0  32.0    -2.7    378  1.9
 10000  -14.4   6.1   275   23   12   8.2   4.5   -0.3  31.5    -3.0    358  1.8
  9750  -13.6   7.5   275   21   11  10.2   5.6   -0.3  31.5    -3.0    328  1.7
  9500  -13.0   8.6   275   20   10   8.7   4.8   -0.3  31.4    -3.1    300  1.5
  9250  -12.3   9.9   275   19   10   8.9   4.9   -0.4  31.3    -3.1    272  1.4
  9000  -11.6  11.1   275   18    9   8.8   4.9   -0.4  31.2    -3.2    245  1.2
  8750  -11.0  12.2   275   17    9   8.9   4.9   -0.5  31.1    -3.3    218  1.1
  8500  -10.3  13.5   275   16    8   8.9   4.9   -0.6  31.0    -3.4    190  1.0
  8250   -9.6  14.7   280   15    8   8.9   4.9   -0.6  30.9    -3.4    163  0.8
  8000   -9.0  15.8   280   14    7   8.9   4.9   -0.7  30.8    -3.5    136  0.7
  7750   -8.3  17.1   280   13    7   8.9   4.9   -0.8  30.6    -3.6    108  0.6
  7500   -7.6  18.3   280   13    7   8.9   4.9   -0.8  30.5    -3.7     81  0.4
  7250   -7.0  19.4   285   13    6   8.9   4.9   -0.9  30.4    -3.7     54  0.3
  7000   -6.3  20.7   285   12    6   8.9   4.9   -1.0  30.2    -3.8     26  0.1
  6750   -5.7  21.7   285   12    6   8.9   4.9   -1.1  30.1    -3.9      M    M
  6500   -5.0  23.0   285   12    6   8.9   4.9   -1.1  29.9    -4.0      M    M
  6250   -4.3  24.3   285   11    6   8.7   4.8   -1.2  29.8    -4.1      M    M
  6000   -3.7  25.3   285   11    6   9.4   5.2   -1.3  29.7    -4.2      M    M
  5750   -3.4  25.9   285    7    4  -9.3  -5.1   -1.8  28.8    -4.7      M    M
  5500   -5.5  22.1   295    3    1 -41.8 -22.9   -4.5  23.8    -7.5      M    M

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

           02/25/2018 at 0800 MST          |       02/25/2018 at 1100 MST
                                           |
CAPE...     0.0    LI...       +1.2        | CAPE...     0.0    LI...       +2.3
CINH...     0.0    K Index...  -6.7        | CINH...     0.0    K Index... -12.3
                                           |
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  255  25 13   2.8   1.5 | -57.0 -70.6  245  30 16   2.4   1.3
 45000 -53.1 -63.6  255  27 14   2.8   1.5 | -53.4 -64.1  245  29 15   2.4   1.3
 40000 -49.6 -57.3  255  29 15   2.2   1.2 | -52.5 -62.5  255  28 15   0.1   0.0
 38000 -48.3 -54.9  255  29 15   2.4   1.3 | -52.5 -62.5  255  29 15   0.0   0.0
 36000 -48.3 -54.9  255  28 15  -0.3  -0.2 | -52.2 -62.0  265  26 13   0.5   0.3
 34000 -48.5 -55.3  255  27 14  -0.3  -0.2 | -51.8 -61.2  285  24 12   0.5   0.3
 32000 -48.5 -55.3  260  25 13   0.2   0.1 | -51.2 -60.2  295  23 12   1.5   0.8
 30000 -48.4 -55.1  260  22 11   0.2   0.1 | -50.3 -58.5  305  23 12   1.5   0.8
 29000 -48.4 -55.1  260  21 11   0.2   0.1 | -49.7 -57.5  310  23 12   3.7   2.0
 28000 -48.3 -54.9  260  19 10   0.1   0.1 | -48.6 -55.5  325  23 12   3.6   2.0
 27000 -48.3 -54.9  265  17  9   0.1   0.1 | -47.6 -53.7  335  24 12   3.6   2.0
 26000 -48.2 -54.8  265  15  8  -0.1  -0.1 | -46.5 -51.7  340  25 13   3.9   2.2
 25000 -47.5 -53.5  270  14  7   3.3   1.8 | -44.6 -48.3  345  24 12   6.8   3.7
 24000 -46.5 -51.7  275  15  8   3.3   1.8 | -42.6 -44.7  340  23 12   6.8   3.7
 23000 -45.5 -49.9  280  16  8   2.9   1.6 | -40.5 -40.9  340  22 11   6.4   3.5
 22000 -43.8 -46.8  280  17  9   6.5   3.6 | -39.3 -38.7  335  19 10   3.7   2.0
 21000 -41.9 -43.4  280  18  9   6.5   3.5 | -38.2 -36.8  330  16  8   3.7   2.0
 20000 -39.9 -39.8  280  19 10   7.9   4.3 | -37.0 -34.6  325  14  7   5.2   2.8
 19500 -38.7 -37.7  280  19 10   8.3   4.5 | -36.2 -33.2  325  14  7   5.3   2.9
 19000 -37.4 -35.3  285  18  9   8.3   4.6 | -35.4 -31.7  325  13  7   5.3   2.9
 18500 -36.2 -33.2  285  18  9   8.3   4.6 | -34.6 -30.3  320  13  6   5.3   2.9
 18000 -34.3 -29.7  285  18  9   8.5   4.7 | -33.4 -28.1  320  12  6   6.5   3.6
 17500 -32.9 -27.2  285  17  9   9.1   5.0 | -32.2 -26.0  315  13  7   8.1   4.4
 17000 -31.6 -24.9  285  16  8   9.1   5.0 | -31.0 -23.8  315  14  7   8.0   4.4
 16500 -30.3 -22.5  285  15  8   8.5   4.7 | -29.9 -21.8  310  15  8   6.5   3.6
 16000 -29.0 -20.2  285  15  8   8.5   4.7 | -28.9 -20.0  305  16  8   6.6   3.6
 15500 -27.7 -17.9  285  14  7   9.1   5.0 | -27.9 -18.2  305  16  8   7.4   4.1
 15000 -26.3 -15.3  290  14  7   9.1   5.0 | -26.8 -16.2  300  15  8   7.2   4.0
 14500 -25.0 -13.0  290  13  7   8.8   4.8 | -25.6 -14.1  300  15  7   8.6   4.7
 14000 -23.7 -10.7  290  13  7   8.7   4.8 | -24.3 -11.7  295  15  8   8.8   4.8
 13500 -22.3  -8.1  290  13  7   9.0   4.9 | -23.0  -9.4  295  16  8   8.9   4.9
 13000 -21.0  -5.8  285  12  6   9.1   5.0 | -21.6  -6.9  295  17  9   9.0   4.9
 12500 -19.6  -3.3  280  12  6   8.6   4.7 | -20.3  -4.5  295  18  9   8.1   4.5
 12000 -18.4  -1.1  285  13  7   8.4   4.6 | -19.2  -2.6  295  17  9   7.9   4.3
 11500 -17.1   1.2  285  14  7   8.6   4.7 | -17.9  -0.2  290  15  8   9.1   5.0
 11000 -15.8   3.6  275   9  5   8.8   4.8 | -16.5   2.3  280  12  6   9.5   5.2
 10500 -14.6   5.7  270   7  4   6.9   3.8 | -15.3   4.5  275  10  5   7.0   3.9
 10250 -14.1   6.6  275   8  4   6.0   3.3 | -14.8   5.4  275  11  6   6.1   3.4
 10000 -13.6   7.5  285   8  4   8.9   4.9 | -14.3   6.3  280  11  6  10.1   5.5
  9750 -12.9   8.8  290   9  5   9.6   5.2 | -13.3   8.1  280  12  6  10.8   5.9
  9500 -12.3   9.9  295  10  5   7.0   3.9 | -12.7   9.1  280  13  6   7.2   4.0
  9250 -11.7  10.9  295  11  5   7.8   4.3 | -12.2  10.0  280  13  7   8.3   4.6
  9000 -11.2  11.8  300  11  6   7.1   3.9 | -11.6  11.1  285  13  7   7.6   4.2
  8750 -10.7  12.7  300  12  6   6.7   3.7 | -11.0  12.2  285  13  7   7.8   4.3
  8500 -10.1  13.8  300  13  7   7.0   3.9 | -10.4  13.3  285  13  7   8.4   4.6
  8250  -9.6  14.7  295  15  7   7.0   3.8 |  -9.8  14.4  285  13  7   8.2   4.5
  8000  -9.1  15.6  295  16  8   7.1   3.9 |  -9.1  15.6  285  12  6   9.6   5.3
  7750  -8.6  16.5  295  16  8   7.2   4.0 |  -8.4  16.9  285  12  6   9.7   5.3
  7500  -8.0  17.6  295  15  8   6.9   3.8 |  -7.7  18.1  285  11  6   8.1   4.4
  7250  -7.5  18.5  295  15  8   7.8   4.3 |  -7.1  19.2  285  11  6   9.2   5.0
  7000  -6.9  19.6  295  15  7   9.9   5.4 |  -6.4  20.5  285  11  5  10.8   5.9
  6750  -6.1  21.0  290  14  7   9.5   5.2 |  -5.6  21.9  285  10  5   9.9   5.4
  6500  -5.5  22.1  290  13  7   7.5   4.1 |  -4.9  23.2  285  10  5   9.2   5.1
  6250  -5.1  22.8  290  12  6   1.7   0.9 |  -4.2  24.4  285   9  5  10.4   5.7
  6000  -5.1  22.8  290  10  5  -0.3  -0.2 |  -3.4  25.9  285   9  4  10.9   6.0
  5750  -5.2  22.6  285   8  4  -4.5  -2.5 |  -2.6  27.3  285   8  4  10.5   5.7
  5500  -6.2  20.8  270   6  3 -21.2 -11.7 |  -1.8  28.8  285   8  4  12.5   6.9

           02/25/2018 at 1400 MST          |       02/25/2018 at 1700 MST
                                           |
CAPE...     0.0    LI...       +7.3        | CAPE...     0.0    LI...       +6.0
CINH...     0.0    K Index... -13.8        | CINH...     0.0    K Index... -10.8
                                           |
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 -57.1 -70.8  250  33 17   2.1   1.1 | -57.0 -70.6  255  33 17   2.3   1.2
 45000 -54.0 -65.2  250  32 16   2.1   1.1 | -53.7 -64.7  255  30 15   2.3   1.2
 40000 -53.7 -64.7  255  29 15  -0.3  -0.2 | -54.3 -65.7  255  29 15  -1.1  -0.6
 38000 -53.9 -65.0  255  28 15  -0.2  -0.1 | -55.0 -67.0  255  29 15  -1.5  -0.8
 36000 -53.9 -65.0  265  26 13   0.1   0.0 | -56.2 -69.2  275  27 14  -1.9  -1.1
 34000 -53.8 -64.8  280  24 12   0.1   0.0 | -57.3 -71.1  295  28 14  -2.0  -1.1
 32000 -53.4 -64.1  290  23 12   1.1   0.6 | -56.2 -69.2  305  29 15   4.1   2.3
 30000 -52.8 -63.0  305  23 12   1.1   0.6 | -53.8 -64.8  310  28 14   4.1   2.3
 29000 -52.1 -61.8  315  24 12   6.0   3.3 | -52.2 -62.0  310  28 14   7.1   3.9
 28000 -50.1 -58.2  320  26 13   5.4   3.0 | -49.5 -57.1  310  27 14   7.0   3.9
 27000 -48.5 -55.3  325  27 14   5.4   3.0 | -47.4 -53.3  310  27 14   7.0   3.9
 26000 -46.7 -52.1  330  28 15   7.9   4.3 | -45.3 -49.5  310  26 14   6.9   3.8
 25000 -44.2 -47.6  330  28 14   8.3   4.5 | -43.3 -45.9  310  26 13   6.9   3.8
 24000 -41.8 -43.2  335  28 14   8.3   4.5 | -41.2 -42.2  310  26 13   6.9   3.8
 23000 -39.3 -38.7  340  28 14   8.6   4.7 | -39.0 -38.2  310  25 13   8.5   4.7
 22000 -36.7 -34.1  340  26 13   8.7   4.8 | -36.5 -33.7  310  24 13   8.4   4.6
 21000 -34.1 -29.4  340  25 13   8.7   4.7 | -34.0 -29.2  310  24 12   8.4   4.6
 20000 -31.6 -24.9  340  23 12   7.8   4.3 | -31.4 -24.5  310  23 12   9.4   5.2
 19500 -30.4 -22.7  335  23 12   7.8   4.3 | -30.0 -22.0  310  22 11   9.4   5.2
 19000 -29.3 -20.7  335  22 11   7.8   4.3 | -28.6 -19.5  310  21 11   9.4   5.2
 18500 -28.1 -18.6  335  21 11   7.7   4.2 | -27.1 -16.8  310  21 11   9.4   5.2
 18000 -27.0 -16.6  335  21 11   7.1   3.9 | -25.7 -14.3  310  20 10   9.1   5.0
 17500 -26.1 -15.0  335  19 10   5.0   2.7 | -24.4 -11.9  310  19 10   8.8   4.8
 17000 -25.4 -13.7  330  18  9   5.2   2.9 | -23.1  -9.6  310  18  9   8.7   4.8
 16500 -24.7 -12.5  325  16  8   3.6   2.0 | -21.9  -7.4  305  17  9   7.5   4.1
 16000 -24.1 -11.4  320  14  7   3.8   2.1 | -20.8  -5.4  305  16  8   7.7   4.2
 15500 -23.6 -10.5  315  12  6   3.3   1.8 | -19.7  -3.5  305  14  7   6.1   3.3
 15000 -23.1  -9.6  310  10  5   3.3   1.8 | -18.8  -1.8  300  13  7   6.1   3.3
 14500 -22.1  -7.8  295   8  4   7.1   3.9 | -17.6   0.3  295  11  6   4.4   2.4
 14000 -21.1  -6.0  290   8  4   6.4   3.5 | -17.0   1.4  290  10  5   4.4   2.4
 13500 -20.0  -4.0  290   8  4   9.2   5.0 | -16.1   3.0  285  10  5   6.7   3.7
 13000 -18.7  -1.7  290   9  5   9.5   5.2 | -15.2   4.6  285   9  5   6.4   3.5
 12500 -17.6   0.3  285  11  6   4.7   2.6 | -14.2   6.4  280  10  5   6.9   3.8
 12000 -16.9   1.6  280  13  7   4.7   2.6 | -13.2   8.2  280  11  6   7.1   3.9
 11500 -16.1   3.0  275  14  7   6.9   3.8 | -12.3   9.9  280  12  6   4.7   2.6
 11000 -15.1   4.8  275  13  7   6.7   3.7 | -11.6  11.1  270  13  7   5.0   2.7
 10500 -13.9   7.0  270  13  7   8.6   4.7 | -10.8  12.6  265  13  7   5.3   2.9
 10250 -13.3   8.1  270  13  6   7.3   4.0 | -10.4  13.3  265  13  7   4.6   2.5
 10000 -12.7   9.1  270  12  6  11.3   6.2 | -10.1  13.8  265  13  7   7.1   3.9
  9750 -11.7  10.9  275  12  6  11.7   6.4 |  -9.4  15.1  260  13  6   8.6   4.7
  9500 -11.1  12.0  275  12  6   8.0   4.4 |  -8.9  16.0  260  12  6   7.3   4.0
  9250 -10.4  13.3  275  11  6   9.0   4.9 |  -8.3  17.1  260  12  6   7.7   4.2
  9000  -9.8  14.4  275  11  6   8.5   4.7 |  -7.7  18.1  255  11  6   7.2   4.0
  8750  -9.1  15.6  275  10  5   8.7   4.8 |  -7.2  19.0  255  10  5   7.5   4.1
  8500  -8.5  16.7  275  10  5   9.1   5.0 |  -6.6  20.1  255  10  5   8.1   4.4
  8250  -7.8  18.0  275   9  5   9.0   4.9 |  -6.0  21.2  255   9  5   7.8   4.3
  8000  -7.1  19.2  275   8  4   8.7   4.8 |  -5.4  22.3  250   8  4   8.7   4.8
  7750  -6.5  20.3  275   7  4   8.3   4.6 |  -4.8  23.4  250   7  4   8.0   4.4
  7500  -5.9  21.4  275   7  4   7.7   4.2 |  -4.2  24.4  250   7  4   6.7   3.7
  7250  -5.3  22.5  275   6  3   9.0   4.9 |  -3.7  25.3  245   6  3   7.3   4.0
  7000  -4.6  23.7  275   6  3  10.7   5.9 |  -3.2  26.2  245   6  3   7.8   4.3
  6750  -3.8  25.2  275   6  3  10.0   5.5 |  -2.6  27.3  240   5  3   7.2   3.9
  6500  -3.1  26.4  275   5  3   9.5   5.2 |  -2.1  28.2  235   4  2   6.9   3.8
  6250  -2.3  27.9  275   5  3  10.4   5.7 |  -1.5  29.3  230   4  2   8.2   4.5
  6000  -1.5  29.3  275   5  3  10.8   5.9 |  -0.9  30.4  225   4  2   9.0   4.9
  5750  -0.8  30.6  275   5  2  10.2   5.6 |  -0.3  31.5  215   3  2   8.0   4.4
  5500   0.0  32.0  275   5  2  11.4   6.3 |   0.2  32.4  210   3  2   4.8   2.6
________________________________________________________________________________

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.

CINH (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.