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 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
000
UXUS97 KBOU 031334
SRGBOU

Soaring Forecast
National Weather Service Denver/Boulder, Colorado
0634 MST Tuesday, March 3, 2015

This forecast is for Tuesday, March 3, 2015:

If the trigger temperature of 47.2 F/8.5 C is reached...then
   Thermal Soaring Index....................... Poor
   Maximum rate of lift........................ 0 ft/min (0.0 m/s)
   Maximum height of thermals.................. 5313 ft MSL (0 ft AGL)

Forecast maximum temperature................... 30.0 F/-1.6 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. None
Thermal soaring outlook for Wednesday 03/04.... Poor

Wave Soaring Index............................. Good
Wave Soaring Index trend (to 1700 MST)......... Becoming poor
Height of stable layer (12-18K ft MSL)......... 17098 ft MSL (11785 ft AGL)
Weak PVA/NVA (through 1700 MST)................ Weak PVA
Potential height of wave....................... 34038 ft MSL (28725 ft AGL)
Wave soaring outlook for Wednesday 03/04....... Good

Remarks... Snow becoming widespread

Sunrise/Sunset.................... 06:29:46 / 17:52:22 MST
Total possible sunshine........... 11 hr 22 min 35 sec (682 min 35 sec)
Altitude of sun at 12:11:18 MST... 43.53 degrees

Upper air data from numerical model forecast valid on 03/03/2015 at 0500 MST

Freezing level.................. 5366 ft MSL (53 ft AGL)
Additional freezing level....... 7504 ft MSL (2191 ft AGL)
Convective condensation level... 15056 ft MSL (9743 ft AGL)
Lifted condensation level....... 9734 ft MSL (4420 ft AGL)
Lifted index.................... +18.8
K index......................... -12.9

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  -58.8 -73.8   240   81   42   1.4   0.8      M     M       M      M    M
 45000  -56.7 -70.1   240   99   51   1.4   0.8      M     M       M      M    M
 40000  -53.3 -63.9   240  103   53   2.2   1.2      M     M       M      M    M
 38000  -52.1 -61.8   245  106   55   2.0   1.1      M     M       M      M    M
 36000  -50.9 -59.6   240  114   59   2.0   1.1      M     M       M      M    M
 34000  -49.7 -57.5   240  123   63   2.2   1.2      M     M       M      M    M
 32000  -46.1 -51.0   240  117   60   6.5   3.6      M     M       M      M    M
 30000  -42.2 -44.0   240  111   57   6.5   3.6      M     M       M      M    M
 29000  -39.8 -39.6   240  105   54   6.2   3.4   34.1  93.3    26.7      M    M
 28000  -38.0 -36.4   240  101   52   6.2   3.4   32.7  90.8    26.0      M    M
 27000  -36.1 -33.0   240   96   49   6.2   3.4   31.4  88.5    25.3      M    M
 26000  -34.3 -29.7   245   93   48   6.3   3.4   30.1  86.2    24.6      M    M
 25000  -32.4 -26.3   245   92   47   6.3   3.4   28.7  83.6    23.8      M    M
 24000  -30.5 -22.9   245   91   47   6.2   3.4   27.4  81.4    23.0      M    M
 23000  -28.8 -19.8   245   89   46   4.4   2.4   26.0  78.8    22.1      M    M
 22000  -27.5 -17.5   245   85   44   4.5   2.5   24.0  75.2    20.8      M    M
 21000  -26.1 -15.0   250   82   42   4.6   2.5   22.2  71.9    19.5      M    M
 20000  -24.5 -12.1   250   76   39   6.4   3.5   20.7  69.3    18.4      M    M
 19500  -23.5 -10.3   255   72   37   6.5   3.5   20.1  68.2    18.0      M    M
 19000  -22.5  -8.5   255   68   35   6.5   3.5   19.5  67.1    17.6      M    M
 18500  -21.6  -6.9   260   65   33   6.4   3.5   19.0  66.2    17.3      M    M
 18000  -20.6  -5.1   260   61   31   5.2   2.9   18.5  65.2    16.9      M    M
 17500  -20.1  -4.2   265   55   28   2.5   1.4   17.3  63.2    16.0      M    M
 17000  -19.7  -3.5   270   48   25   2.3   1.3   16.1  61.0    15.0      M    M
 16500  -19.3  -2.7   275   42   22   4.4   2.4   15.0  59.0    14.2      M    M
 16000  -18.6  -1.5   280   38   19   4.3   2.3   14.1  57.3    13.4      M    M
 15500  -17.4   0.7   290   32   16   7.2   4.0   13.0  55.3    12.5      M    M
 15000  -16.4   2.5   295   28   14   6.9   3.8   12.5  54.5    12.2      M    M
 14500  -15.3   4.5   295   25   13   7.8   4.3   12.1  53.8    11.9      M    M
 14000  -14.1   6.6   300   22   11   7.8   4.3   11.8  53.2    11.6      M    M
 13500  -13.0   8.6   300   20   10   8.2   4.5   11.5  52.7    11.4      M    M
 13000  -11.7  10.9   300   23   12   8.3   4.5   11.2  52.2    11.2      M    M
 12500  -10.5  13.1   295   26   13   7.7   4.2   11.0  51.7    11.1      M    M
 12000   -9.4  15.1   295   30   16   7.6   4.1   10.6  51.1    10.8      M    M
 11500   -8.3  17.1   295   35   18   7.3   4.0   10.2  50.4    10.5      M    M
 11000   -7.2  19.0   295   39   20   7.3   4.0    9.8  49.7    10.1      M    M
 10500   -6.2  20.8   290   43   22   7.0   3.9    9.4  49.0     9.8      M    M
 10250   -5.7  21.7   290   45   23   6.8   3.7    9.2  48.6     9.6      M    M
 10000   -5.2  22.6   290   47   24   7.7   4.2    9.0  48.2     9.4      M    M
  9750   -4.5  23.9   290   47   24   8.5   4.7    8.9  48.0     9.3      M    M
  9500   -3.9  25.0   290   48   25   8.3   4.5    8.8  47.8     9.2      M    M
  9250   -3.3  26.1   290   49   25   8.7   4.8    8.7  47.6     9.1      M    M
  9000   -2.7  27.1   290   50   26   7.3   4.0    8.6  47.4     9.1      M    M
  8750   -2.2  28.0   290   51   26   5.9   3.2    8.3  46.9     8.8      M    M
  8500   -1.8  28.8   290   49   25   6.3   3.4    8.0  46.4     8.5      M    M
  8250   -1.3  29.7   290   48   25   6.8   3.7    7.7  45.9     8.3      M    M
  8000   -0.9  30.4   285   46   24   5.2   2.8    7.5  45.5     8.0      M    M
  7750   -0.6  30.9   285   45   23   5.5   3.0    7.1  44.8     7.7      M    M
  7500   -0.0  32.0   285   43   22   7.5   4.1    6.9  44.4     7.5      M    M
  7250    0.5  32.9   285   40   21   6.8   3.8    6.7  44.0     7.3      M    M
  7000    1.0  33.8   280   38   19   7.5   4.1    6.5  43.7     7.1      M    M
  6750    1.6  34.9   280   35   18   8.3   4.5    6.3  43.4     7.0      M    M
  6500    2.2  36.0   280   34   17   9.0   4.9    6.2  43.2     6.9      M    M
  6250    2.9  37.2   280   32   17   7.2   4.0    6.2  43.1     6.8      M    M
  6000    3.2  37.8   280   30   15   0.4   0.2    5.7  42.3     6.4      M    M
  5750    2.7  36.9   275   25   13 -12.9  -7.1    4.6  40.3     5.3      M    M
  5500    1.2  34.2   270   17    9 -25.3 -13.9    2.4  36.3     3.0      M    M

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

           03/03/2015 at 0800 MST          |       03/03/2015 at 1100 MST
                                           |
K index... +0.4  LI... +278.8              | K index... -1.6  LI... +279.8
CAPE... 0.0  CIN... -0.0                   | 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 -58.2 -72.8  250  71 37   2.4   1.3 | -57.3 -71.1  250  67 34   1.9   1.1
 45000 -54.6 -66.3  245  95 49   2.4   1.3 | -54.5 -66.1  250  90 46   1.9   1.1
 40000 -51.8 -61.2  245 101 52   1.7   0.9 | -51.8 -61.2  240 102 52   1.6   0.9
 38000 -50.8 -59.4  240 105 54   1.7   0.9 | -50.8 -59.4  240 106 55   1.8   1.0
 36000 -49.8 -57.6  240 112 58   1.7   0.9 | -49.8 -57.6  240 111 57   1.8   1.0
 34000 -48.7 -55.7  235 119 61   1.4   0.8 | -48.7 -55.7  235 117 60   1.5   0.8
 32000 -45.9 -50.6  240 117 60   5.2   2.8 | -46.0 -50.8  235 116 60   5.1   2.8
 30000 -42.8 -45.0  240 114 59   5.2   2.8 | -42.9 -45.2  235 114 59   5.0   2.8
 29000 -40.8 -41.4  240 109 56   5.7   3.1 | -41.0 -41.8  235 111 57   5.3   2.9
 28000 -39.1 -38.4  240 105 54   5.7   3.1 | -39.4 -38.9  235 107 55   5.3   2.9
 27000 -37.4 -35.3  240 100 52   5.7   3.1 | -37.8 -36.0  240 104 53   5.3   2.9
 26000 -35.7 -32.3  245  97 50   5.1   2.8 | -36.3 -33.3  240 100 51   4.7   2.6
 25000 -34.2 -29.6  245  95 49   5.1   2.8 | -34.8 -30.6  240  95 49   4.8   2.6
 24000 -32.7 -26.9  245  93 48   5.1   2.8 | -33.4 -28.1  240  91 47   4.8   2.6
 23000 -31.1 -24.0  245  90 47   6.1   3.3 | -31.9 -25.4  240  86 44   5.9   3.3
 22000 -29.3 -20.7  245  85 44   6.0   3.3 | -30.2 -22.4  240  81 42   5.9   3.2
 21000 -27.5 -17.5  245  80 41   5.9   3.3 | -28.4 -19.1  245  75 39   5.9   3.2
 20000 -25.9 -14.6  250  74 38   4.8   2.6 | -26.6 -15.9  245  70 36   6.5   3.5
 19500 -25.2 -13.4  250  69 36   4.8   2.6 | -25.6 -14.1  245  68 35   6.5   3.5
 19000 -24.5 -12.1  250  65 33   4.8   2.6 | -24.7 -12.5  250  65 33   6.5   3.5
 18500 -23.7 -10.7  255  61 31   4.8   2.6 | -23.7 -10.7  250  62 32   6.4   3.5
 18000 -23.0  -9.4  255  56 29   4.2   2.3 | -22.7  -8.9  250  60 31   5.5   3.0
 17500 -22.7  -8.9  260  51 26   1.1   0.6 | -22.4  -8.3  255  55 28   1.0   0.6
 17000 -22.5  -8.5  260  44 23   0.9   0.5 | -22.2  -8.0  255  49 25   1.0   0.5
 16500 -22.1  -7.8  265  39 20   5.9   3.2 | -21.8  -7.2  260  44 23   4.8   2.6
 16000 -21.2  -6.2  265  36 18   6.1   3.4 | -21.0  -5.8  260  41 21   5.0   2.7
 15500 -19.7  -3.5  270  33 17   7.7   4.2 | -20.3  -4.5  265  39 20   6.1   3.3
 15000 -18.6  -1.5  270  32 17   7.5   4.1 | -18.8  -1.8  265  36 19   6.8   3.7
 14500 -17.5   0.5  275  33 17   7.4   4.1 | -17.7   0.1  270  35 18   7.8   4.3
 14000 -16.4   2.5  280  35 18   7.4   4.1 | -16.6   2.1  270  33 17   7.8   4.3
 13500 -15.3   4.5  280  36 18   7.5   4.1 | -15.4   4.3  270  32 16   7.8   4.3
 13000 -14.2   6.4  280  36 18   7.6   4.2 | -14.3   6.3  275  31 16   7.9   4.3
 12500 -13.1   8.4  285  35 18   6.5   3.5 | -13.1   8.4  275  29 15   7.3   4.0
 12000 -12.3   9.9  285  34 17   6.1   3.4 | -12.1  10.2  275  28 15   7.2   4.0
 11500 -11.5  11.3  285  32 16   3.7   2.0 | -11.3  11.7  275  27 14   0.2   0.1
 11000 -11.1  12.0  285  28 14   3.0   1.6 | -11.7  10.9  270  23 12  -2.3  -1.3
 10500 -10.8  12.6  290  23 12   0.3   0.2 | -12.3   9.9  270  19 10  -6.9  -3.8
 10250 -10.8  12.6  290  21 11  -0.7  -0.4 | -12.9   8.8  265  16  8  -7.7  -4.2
 10000 -10.9  12.4  300  18  9   0.1   0.1 | -13.5   7.7  260  13  7  -9.7  -5.3
  9750 -10.9  12.4  305  16  8  -0.5  -0.3 | -14.2   6.4  255  10  5  -4.3  -2.4
  9500 -11.0  12.2  325  14  7  -2.2  -1.2 | -14.0   6.8  245   7  3   5.8   3.2
  9250 -11.1  12.0  340  13  7  -2.6  -1.4 | -13.5   7.7  225   5  2   6.4   3.5
  9000 -11.3  11.7  360  14  7  -2.1  -1.1 | -13.0   8.6  190   3  2   7.4   4.1
  8750 -11.4  11.5  015  16  8   1.5   0.8 | -12.5   9.5  150   3  2   6.7   3.7
  8500 -11.1  12.0  020  17  9   3.8   2.1 | -12.1  10.2  125   3  2   5.0   2.7
  8250 -10.9  12.4  025  19 10   2.4   1.3 | -11.7  10.9  100   4  2   5.3   2.9
  8000 -10.7  12.7  025  20 10   5.7   3.1 | -11.3  11.7  085   5  2   5.8   3.2
  7750 -10.0  14.0  030  21 11   9.7   5.3 | -10.8  12.6  065   6  3   7.2   4.0
  7500  -9.3  15.3  025  21 11   9.3   5.1 | -10.3  13.5  055   6  3   7.4   4.1
  7250  -8.6  16.5  025  21 11   9.1   5.0 |  -9.7  14.5  050   7  3   7.7   4.2
  7000  -8.0  17.6  025  21 11   9.5   5.2 |  -9.1  15.6  045   7  4   9.8   5.4
  6750  -7.3  18.9  025  20 10   7.4   4.0 |  -8.3  17.1  040   7  4  10.5   5.8
  6500  -6.9  19.6  025  20 10   5.0   2.8 |  -7.6  18.3  035   7  4   9.6   5.2
  6250  -6.5  20.3  025  19 10   4.7   2.6 |  -6.9  19.6  030   7  4  10.6   5.8
  6000  -6.2  20.8  020  15  8   3.8   2.1 |  -6.1  21.0  030   7  3  11.9   6.5
  5750  -6.0  21.2  015  12  6   5.0   2.8 |  -5.2  22.6  025   7  3  10.1   5.6
  5500  -5.4  22.3  010   8  4   9.4   5.2 |  -4.5  23.9  020   6  3  10.3   5.7

           03/03/2015 at 1400 MST          |       03/03/2015 at 1700 MST
                                           |
K index... +11.2  LI... +275.2             | K index... +13.4  LI... +274.7
CAPE... 0.0  CIN... M                      | CAPE... 0.0  CIN... -0.8
                                           |
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 -56.9 -70.4  250  66 34   2.2   1.2 | -57.0 -70.6  250  70 36   2.5   1.4
 45000 -53.7 -64.7  245  90 46   2.2   1.2 | -53.2 -63.8  250  88 45   2.5   1.4
 40000 -51.8 -61.2  245  98 50   1.1   0.6 | -51.1 -60.0  245  87 45   1.2   0.7
 38000 -50.9 -59.6  240 100 52   2.6   1.4 | -50.3 -58.5  245  86 44   2.6   1.5
 36000 -49.4 -56.9  240 103 53   2.6   1.4 | -48.6 -55.5  240  91 47   2.5   1.4
 34000 -47.8 -54.0  235 105 54   2.5   1.4 | -47.1 -52.8  240  96 49   2.4   1.3
 32000 -45.4 -49.7  235 107 55   4.4   2.4 | -45.1 -49.2  240  99 51   3.4   1.9
 30000 -42.7 -44.9  235 108 56   4.4   2.4 | -43.1 -45.6  240 102 53   3.4   1.9
 29000 -40.9 -41.6  235 107 55   5.4   2.9 | -42.0 -43.6  240 101 52   4.0   2.2
 28000 -39.3 -38.7  235 104 53   5.4   2.9 | -40.8 -41.4  240  99 51   4.0   2.2
 27000 -37.6 -35.7  235 101 52   5.4   3.0 | -39.5 -39.1  240  96 49   4.0   2.2
 26000 -36.2 -33.2  235  98 50   3.2   1.8 | -38.4 -37.1  240  93 48   3.1   1.7
 25000 -35.2 -31.4  240  91 47   3.5   1.9 | -37.6 -35.7  245  84 43   2.7   1.5
 24000 -34.1 -29.4  240  85 44   3.5   1.9 | -36.8 -34.2  245  76 39   2.7   1.5
 23000 -33.0 -27.4  240  79 41   4.6   2.5 | -36.0 -32.8  250  67 35   4.0   2.2
 22000 -31.6 -24.9  245  74 38   4.8   2.6 | -34.4 -29.9  250  61 31   5.1   2.8
 21000 -30.2 -22.4  250  69 35   4.8   2.6 | -32.9 -27.2  255  54 28   5.2   2.8
 20000 -28.7 -19.7  250  63 32   5.7   3.1 | -31.1 -24.0  255  48 25   8.4   4.6
 19500 -27.8 -18.0  250  60 31   5.7   3.1 | -29.9 -21.8  255  44 22   8.1   4.4
 19000 -27.0 -16.6  250  56 29   5.7   3.1 | -28.7 -19.7  255  40 20   8.0   4.4
 18500 -26.2 -15.2  250  53 27   5.7   3.1 | -26.9 -16.4  255  34 17   8.1   4.4
 18000 -25.3 -13.5  250  49 25   5.6   3.1 | -25.7 -14.3  250  30 15   8.3   4.6
 17500 -24.6 -12.3  255  45 23   4.8   2.7 | -24.5 -12.1  255  29 15   8.5   4.7
 17000 -23.8 -10.8  255  40 21   4.7   2.6 | -23.2  -9.8  255  29 15   8.5   4.7
 16500 -23.0  -9.4  255  36 18   7.9   4.3 | -22.0  -7.6  260  28 15   8.1   4.4
 16000 -21.8  -7.2  255  34 18   8.2   4.5 | -20.8  -5.4  260  27 14   8.1   4.5
 15500 -19.9  -3.8  255  31 16   8.1   4.4 | -19.6  -3.3  260  27 14   7.9   4.3
 15000 -18.7  -1.7  255  29 15   8.1   4.4 | -18.4  -1.1  260  26 13   7.9   4.4
 14500 -17.5   0.5  255  27 14   8.8   4.8 | -17.3   0.9  265  25 13   7.5   4.1
 14000 -16.2   2.8  255  25 13   8.9   4.9 | -16.2   2.8  265  24 12   7.3   4.0
 13500 -14.9   5.2  255  24 12   8.4   4.6 | -15.1   4.8  265  23 12   7.2   3.9
 13000 -13.7   7.3  255  23 12   8.1   4.5 | -14.1   6.6  265  24 12   7.0   3.9
 12500 -12.5   9.5  250  22 11   7.1   3.9 | -13.0   8.6  260  24 12   6.3   3.5
 12000 -11.6  11.1  250  22 11   6.5   3.6 | -12.2  10.0  260  22 11   5.6   3.1
 11500 -10.6  12.9  250  21 11   4.7   2.6 | -11.4  11.5  260  20 10   4.5   2.5
 11000 -10.1  13.8  245  21 11   3.8   2.1 | -10.9  12.4  255  20 11   3.5   1.9
 10500  -9.7  14.5  245  21 11   0.3   0.2 | -10.4  13.3  250  21 11   1.6   0.9
 10250  -9.8  14.4  245  20 10  -1.5  -0.8 | -10.4  13.3  245  20 10   0.2   0.1
 10000  -9.8  14.4  245  20 10  -1.3  -0.7 | -10.3  13.5  240  19 10   0.1   0.1
  9750 -10.0  14.0  245  19 10  -2.6  -1.4 | -10.3  13.5  240  18  9  -0.5  -0.3
  9500 -10.2  13.6  245  17  9  -3.2  -1.7 | -10.3  13.5  235  17  9   1.0   0.5
  9250 -10.4  13.3  240  15  8  -2.6  -1.4 | -10.2  13.6  225  16  8   2.0   1.1
  9000 -10.6  12.9  235  13  7  -4.0  -2.2 | -10.1  13.8  210  14  7   1.5   0.8
  8750 -10.9  12.4  225  11  6  -1.3  -0.7 |  -9.9  14.2  200  14  7   3.4   1.9
  8500 -10.8  12.6  220   9  5   2.7   1.5 |  -9.6  14.7  190  13  7   5.2   2.8
  8250 -10.6  12.9  200   7  4   2.1   1.2 |  -9.2  15.4  185  12  6   4.5   2.5
  8000 -10.4  13.3  180   6  3   2.9   1.6 |  -8.9  16.0  175  11  6   5.5   3.0
  7750 -10.2  13.6  145   5  3   5.5   3.0 |  -8.4  16.9  160  10  5   6.4   3.5
  7500  -9.7  14.5  120   5  3   7.1   3.9 |  -8.0  17.6  150  10  5   6.1   3.3
  7250  -9.2  15.4  105   6  3   6.3   3.5 |  -7.5  18.5  140   9  5   5.7   3.1
  7000  -8.7  16.3  090   6  3   9.1   5.0 |  -7.1  19.2  125  10  5   6.9   3.8
  6750  -7.9  17.8  075   7  3  10.7   5.9 |  -6.5  20.3  115   9  5   8.0   4.4
  6500  -7.2  19.0  065   7  3   9.0   4.9 |  -6.0  21.2  105   9  5   7.2   4.0
  6250  -6.5  20.3  055   7  4  10.2   5.6 |  -5.4  22.3  095   9  5   8.0   4.4
  6000  -5.7  21.7  055   7  4  11.9   6.5 |  -4.8  23.4  090   8  4   9.4   5.1
  5750  -4.8  23.4  050   7  3  10.7   5.9 |  -4.1  24.6  085   7  4   9.0   4.9
  5500  -4.1  24.6  050   6  3  11.0   6.0 |  -3.5  25.7  075   6  3   8.5   4.7
________________________________________________________________________________

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.