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 Grand Junction Soaring Forecast

We are testing a new soaring forecast program. During this testing phase, the soaring forecast may not always be available or may not be updated. Please check the date of the soaring forecast before using the data. Feedback to our webmaster regarding this new soaring forecast program will be appreciated.

 


945
UXUS97 KGJT 251247
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
0647 MDT Sunday, August 25, 2019

This forecast is for Sunday, August 25, 2019:

If the trigger temperature of 88.6 F/31.4 C is reached...then
Thermal Soaring Index....................... Excellent
Maximum rate of lift........................ 1138 ft/min (5.8 m/s)
Maximum height of thermals.................. 17376 ft MSL (12537 ft AGL)

Forecast maximum temperature................... 98.0 F/37.1 C
Time of trigger temperature.................... 1230 MDT
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................. 13360 ft MSL (8521 ft AGL)
Thermal soaring outlook for Monday 08/26....... Excellent

Wave Soaring Index............................. Not available

Remarks...

***ATTENTION Soaring Forecast Users***The National Weather Service in Boulder wants to hear from you.
Please send and email to paul.t.schlatter@noaa.gov and let us know how you use the Soaring Forecast. Thanks!

Sunrise/Sunset.................... 06:36:33 / 19:55:56 MDT
Total possible sunshine........... 13 hr 19 min 22 sec (799 min 22 sec)
Altitude of sun at 13:16:15 MDT... 61.33 degrees

Upper air data from rawinsonde observation taken on 08/25/2019 at 0600 MDT

Freezing level.................. 16215 ft MSL (11376 ft AGL)
Convective condensation level... 19829 ft MSL (14990 ft AGL)
Lifted condensation level....... 19251 ft MSL (14412 ft AGL)
Lifted index.................... +2.6
K index......................... +18.2

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 -67.6 -89.7 320 38 20 7.6 4.1 81.0 177.8 25.7 M M
45000 -62.1 -79.8 325 47 24 -4.8 -2.7 64.6 148.3 17.5 M M
40000 -53.5 -64.3 340 44 23 8.9 4.9 55.2 131.4 12.4 M M
38000 -48.2 -54.8 335 43 22 9.2 5.0 54.4 129.9 12.2 M M
36000 -42.9 -45.2 325 42 22 8.4 4.6 53.6 128.5 11.9 M M
34000 -37.7 -35.9 320 41 21 8.7 4.8 52.6 126.6 11.5 M M
32000 -32.6 -26.7 320 41 21 7.9 4.3 50.8 123.4 10.4 M M
30000 -27.3 -17.1 315 42 22 8.8 4.8 50.0 122.1 10.1 M M
29000 -24.7 -12.5 315 42 22 8.8 4.8 49.6 121.3 9.9 M M
28000 -22.1 -7.8 315 43 22 8.9 4.9 49.3 120.7 9.8 M M
27000 -20.2 -4.4 310 43 22 5.4 3.0 48.0 118.3 8.8 M M
26000 -17.9 -0.2 310 44 22 8.3 4.6 47.1 116.8 8.3 M M
25000 -15.4 4.3 315 45 23 7.4 4.0 46.6 115.9 7.9 M M
24000 -13.5 7.7 315 46 24 7.1 3.9 45.5 113.9 7.1 M M
23000 -11.0 12.2 315 42 22 5.8 3.2 44.9 112.8 6.8 M M
22000 -11.0 12.2 315 39 20 4.6 2.5 41.5 106.8 3.9 M M
21000 -9.4 15.1 310 35 18 7.6 4.2 40.0 104.0 2.6 M M
20000 -7.1 19.2 310 31 16 7.8 4.3 39.3 102.7 2.0 M M
19500 -6.0 21.2 305 30 15 7.8 4.3 39.0 102.1 1.7 M M
19000 -4.8 23.4 305 29 15 8.1 4.4 38.6 101.5 1.4 M M
18500 -3.8 25.2 305 29 15 5.4 3.0 38.1 100.6 1.0 M M
18000 -2.7 27.1 305 28 15 7.5 4.1 37.5 99.5 0.5 M M
17500 -1.1 30.0 310 28 14 5.2 2.9 37.0 98.5 0.0 M M
17000 -1.6 29.1 310 28 14 1.0 0.5 35.1 95.1 -2.0 1138 5.8
16500 -0.5 31.1 310 27 14 9.1 5.0 34.8 94.6 -2.4 1092 5.5
16000 0.9 33.6 310 27 14 9.2 5.0 34.7 94.5 -2.5 1036 5.3
15500 2.2 36.0 305 25 13 9.2 5.0 34.6 94.2 -2.6 980 5.0
15000 3.6 38.5 300 23 12 9.2 5.0 34.5 94.0 -2.7 924 4.7
14500 5.0 41.0 295 22 11 9.2 5.0 34.4 93.9 -2.8 868 4.4
14000 6.4 43.5 290 21 11 9.2 5.0 34.3 93.8 -2.9 812 4.1
13500 7.7 45.9 290 20 10 9.0 5.0 34.2 93.6 -3.0 756 3.8
13000 9.0 48.2 285 19 10 8.6 4.7 34.0 93.3 -3.2 702 3.6
12500 10.3 50.5 285 18 9 8.7 4.8 33.9 93.0 -3.3 649 3.3
12000 11.6 52.9 280 17 9 8.7 4.8 33.7 92.7 -3.5 596 3.0
11500 12.9 55.2 280 15 8 8.7 4.8 33.5 92.3 -3.8 543 2.8
11000 14.1 57.4 275 13 7 8.7 4.8 33.3 92.0 -4.0 490 2.5
10500 15.4 59.7 270 11 6 8.5 4.7 33.2 91.7 -4.2 437 2.2
10250 16.0 60.8 270 12 6 8.1 4.5 33.1 91.5 -4.3 411 2.1
10000 16.6 61.9 270 13 7 8.1 4.4 32.9 91.3 -4.4 386 2.0
9750 17.2 63.0 270 14 7 8.1 4.5 32.8 91.0 -4.6 360 1.8
9500 17.8 64.0 270 15 8 8.1 4.5 32.7 90.8 -4.7 335 1.7
9250 18.4 65.1 270 17 9 8.1 4.5 32.6 90.6 -4.8 309 1.6
9000 19.0 66.2 270 18 9 8.1 4.5 32.5 90.4 -4.9 284 1.4
8750 19.6 67.3 270 17 9 8.1 4.5 32.3 90.2 -5.1 258 1.3
8500 20.2 68.4 270 16 8 8.1 4.5 32.2 89.9 -5.2 233 1.2
8250 20.8 69.4 275 14 7 8.1 4.5 32.1 89.7 -5.4 207 1.1
8000 21.5 70.7 275 13 7 8.1 4.4 31.9 89.5 -5.5 182 0.9
7750 22.1 71.8 275 11 6 8.1 4.5 31.8 89.3 -5.6 156 0.8
7500 22.7 72.9 275 8 4 8.0 4.4 31.7 89.0 -5.8 131 0.7
7250 23.3 73.9 275 5 3 8.5 4.7 31.5 88.8 -5.9 105 0.5
7000 23.8 74.8 280 3 1 4.7 2.6 31.4 88.5 -6.1 81 0.4
6750 24.0 75.2 190 1 1 1.2 0.7 30.8 87.4 -6.7 69 0.3
6500 24.2 75.6 150 4 2 3.1 1.7 30.2 86.3 -7.3 56 0.3
6250 24.3 75.7 145 7 4 -0.8 -0.5 29.6 85.3 -7.8 44 0.2
6000 24.1 75.4 140 10 5 -3.6 -2.0 28.6 83.5 -8.8 44 0.2
5750 24.0 75.2 140 10 5 2.9 1.6 27.8 82.1 -9.7 39 0.2
5500 24.4 75.9 135 8 4 8.7 4.8 27.6 81.6 -10.0 19 0.1
5250 24.5 76.1 125 7 4 -13.7 -7.5 27.0 80.5 -10.7 9 0.0
5000 22.0 71.6 120 6 3 -51.2 -28.1 23.7 74.6 -13.9 78 0.4

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

08/25/2019 at 0900 MDT | 08/25/2019 at 1200 MDT
|
CAPE... 0.0 LI... +3.9 | CAPE... 0.0 LI... +3.3
CINH... 0.0 K Index... +15.3 | CINH... 0.0 K Index... +16.1
|
Height Temperature Wnd WndSpd Lapse Rate | Temperature Wnd WndSpd Lapse Rate
ft MSL deg C deg F Dir kt m/s C/km F/kft | deg C deg F Dir kt m/s C/km F/kft
--------------------------------------------------------------------------------
50000 -66.0 -86.8 320 14 7 1.1 0.6 | -66.2 -87.2 310 12 6 0.7 0.4
45000 -62.1 -79.8 320 18 9 5.7 3.1 | -62.1 -79.8 310 16 8 6.2 3.4
40000 -52.5 -62.5 325 19 10 8.2 4.5 | -52.4 -62.3 305 17 9 8.1 4.4
38000 -47.6 -53.7 320 21 11 8.2 4.5 | -47.6 -53.7 305 19 10 8.1 4.4
36000 -42.7 -44.9 315 22 11 8.2 4.5 | -42.7 -44.9 305 20 10 8.2 4.5
34000 -37.7 -35.9 315 23 12 8.3 4.5 | -37.1 -34.8 305 22 11 8.4 4.6
32000 -32.7 -26.9 315 23 12 8.5 4.6 | -32.1 -25.8 305 23 12 8.4 4.6
30000 -28.0 -18.4 310 23 12 7.9 4.3 | -27.3 -17.1 305 23 12 7.9 4.3
29000 -25.6 -14.1 310 22 11 7.9 4.3 | -25.0 -13.0 305 22 12 7.9 4.3
28000 -23.2 -9.8 310 22 11 7.9 4.3 | -22.6 -8.7 300 22 11 7.6 4.2
27000 -20.9 -5.6 310 21 11 7.9 4.3 | -20.4 -4.7 300 21 11 7.6 4.2
26000 -17.9 -0.2 305 19 10 7.9 4.4 | -18.1 -0.6 300 20 10 7.6 4.2
25000 -15.6 3.9 305 18 9 7.0 3.8 | -15.8 3.6 295 19 10 7.3 4.0
24000 -13.6 7.5 305 18 9 6.8 3.7 | -13.8 7.2 295 18 9 6.8 3.8
23000 -11.5 11.3 305 17 9 6.8 3.7 | -11.7 10.9 295 18 9 6.9 3.8
22000 -9.6 14.7 300 17 9 5.5 3.0 | -9.7 14.5 295 17 9 6.2 3.4
21000 -8.0 17.6 300 16 8 5.3 2.9 | -7.8 18.0 295 16 8 5.3 2.9
20000 -6.5 20.3 300 16 8 5.3 2.9 | -6.2 20.8 295 16 8 5.4 2.9
19500 -5.7 21.7 300 16 8 5.4 3.0 | -5.4 22.3 295 16 8 5.5 3.0
19000 -4.9 23.2 300 15 8 5.8 3.2 | -4.6 23.7 295 15 8 5.6 3.1
18500 -4.0 24.8 295 15 8 5.8 3.2 | -3.8 25.2 290 15 8 5.6 3.1
18000 -3.2 26.2 295 14 7 6.0 3.3 | -3.0 26.6 290 15 8 5.8 3.2
17500 -2.3 27.9 290 14 7 6.2 3.4 | -2.2 28.0 285 14 7 5.9 3.2
17000 -1.5 29.3 290 14 7 6.6 3.6 | -1.4 29.5 280 14 7 6.7 3.7
16500 -0.4 31.3 290 14 7 7.6 4.2 | -0.3 31.5 280 14 7 7.7 4.2
16000 0.7 33.3 285 13 7 7.5 4.1 | 0.8 33.4 280 14 7 7.7 4.2
15500 1.8 35.2 285 13 7 8.9 4.9 | 2.0 35.6 280 13 7 8.9 4.9
15000 3.2 37.8 285 12 6 8.8 4.8 | 3.3 37.9 280 12 6 8.8 4.8
14500 4.5 40.1 285 12 6 8.9 4.9 | 4.6 40.3 280 12 6 8.8 4.8
14000 5.8 42.4 290 11 6 8.9 4.9 | 5.9 42.6 280 11 6 8.8 4.8
13500 7.1 44.8 290 11 5 8.9 4.9 | 7.2 45.0 280 10 5 8.7 4.8
13000 8.5 47.3 290 10 5 8.9 4.9 | 8.5 47.3 280 10 5 8.7 4.8
12500 9.8 49.6 290 10 5 8.7 4.8 | 9.8 49.6 280 9 5 8.8 4.8
12000 11.1 52.0 290 9 5 8.2 4.5 | 11.1 52.0 280 9 5 8.9 4.9
11500 12.3 54.1 290 9 5 8.2 4.5 | 12.4 54.3 280 8 4 8.8 4.8
11000 13.4 56.1 285 9 4 7.1 3.9 | 13.7 56.7 280 8 4 8.2 4.5
10500 14.5 58.1 280 8 4 5.4 2.9 | 15.0 59.0 275 8 4 5.6 3.1
10250 14.8 58.6 280 8 4 5.4 2.9 | 15.3 59.5 275 7 4 6.0 3.3
10000 15.4 59.7 280 8 4 7.8 4.3 | 15.9 60.6 270 7 4 9.8 5.4
9750 15.9 60.6 275 8 4 7.2 3.9 | 16.6 61.9 270 7 4 8.9 4.9
9500 16.4 61.5 275 7 4 7.3 4.0 | 17.3 63.1 270 7 4 8.8 4.8
9250 17.0 62.6 270 7 4 6.5 3.6 | 17.9 64.2 270 7 4 8.0 4.4
9000 17.4 63.3 270 7 4 6.0 3.3 | 18.5 65.3 265 7 4 8.1 4.4
8750 17.9 64.2 265 7 3 6.1 3.3 | 19.1 66.4 265 7 3 8.4 4.6
8500 18.7 65.7 265 6 3 5.1 2.8 | 19.7 67.5 265 7 3 7.9 4.3
8250 19.1 66.4 265 6 3 5.1 2.8 | 20.2 68.4 265 6 3 6.2 3.4
8000 19.5 67.1 260 5 3 5.9 3.2 | 20.7 69.3 265 6 3 7.6 4.2
7750 19.9 67.8 255 5 2 5.1 2.8 | 22.0 71.6 260 5 3 8.7 4.8
7500 20.2 68.4 250 4 2 3.9 2.1 | 22.6 72.7 265 5 2 7.9 4.3
7250 20.5 68.9 250 4 2 4.2 2.3 | 23.2 73.8 270 4 2 8.7 4.8
7000 20.9 69.6 245 4 2 6.1 3.3 | 24.0 75.2 270 4 2 11.2 6.2
6750 21.4 70.5 225 3 1 6.2 3.4 | 24.8 76.6 265 4 2 11.4 6.3
6500 21.8 71.2 220 2 1 5.4 3.0 | 25.6 78.1 265 4 2 11.0 6.0
6250 22.2 72.0 210 2 1 5.1 2.8 | 26.5 79.7 270 4 2 10.0 5.5
6000 22.6 72.7 190 1 1 8.3 4.5 | 27.2 81.0 275 4 2 12.2 6.7
5750 23.5 74.3 185 1 1 16.4 9.0 | 28.5 83.3 270 4 2 24.5 13.5
5500 24.6 76.3 135 1 0 8.1 4.5 | 30.7 87.3 275 3 2 34.0 18.6
5250 M M M M M M M | M M M M M M M
5000 M M M M M M M | M M M M M M M

08/25/2019 at 1500 MDT | 08/25/2019 at 1800 MDT
|
CAPE... +0.2 LI... +1.9 | CAPE... +10.0 LI... +0.7
CINH... -0.3 K Index... +18.6 | CINH... -2.8 K Index... +21.6
|
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 -66.2 -87.2 300 12 6 0.6 0.3 | -65.9 -86.6 295 13 7 0.8 0.4
45000 -62.1 -79.8 295 17 9 6.2 3.4 | -62.0 -79.6 290 18 9 5.8 3.2
40000 -52.3 -62.1 290 21 11 8.2 4.5 | -52.6 -62.7 285 22 11 8.2 4.5
38000 -47.4 -53.3 290 21 11 8.2 4.5 | -47.8 -54.0 290 23 12 8.1 4.5
36000 -42.4 -44.3 290 22 11 8.3 4.6 | -42.9 -45.2 290 24 12 8.2 4.5
34000 -37.4 -35.3 295 22 11 8.4 4.6 | -37.3 -35.1 290 24 12 8.4 4.6
32000 -32.3 -26.1 295 23 12 8.6 4.7 | -32.2 -26.0 290 24 12 8.5 4.6
30000 -27.4 -17.3 295 22 11 8.1 4.4 | -27.4 -17.3 290 23 12 8.1 4.5
29000 -25.0 -13.0 295 21 11 8.1 4.4 | -24.9 -12.8 290 22 12 8.2 4.5
28000 -22.6 -8.7 295 21 11 7.6 4.2 | -22.6 -8.7 290 22 11 7.5 4.1
27000 -20.4 -4.7 295 20 10 7.6 4.1 | -20.3 -4.5 295 22 11 7.6 4.1
26000 -17.5 0.5 295 20 10 7.6 4.1 | -18.1 -0.6 295 21 11 7.6 4.1
25000 -15.3 4.5 295 19 10 6.6 3.6 | -15.8 3.6 295 21 11 6.9 3.8
24000 -13.4 7.9 295 19 10 6.5 3.6 | -14.0 6.8 295 20 10 6.1 3.4
23000 -11.5 11.3 295 18 9 6.5 3.6 | -12.2 10.0 295 20 10 6.2 3.4
22000 -9.6 14.7 295 18 9 5.2 2.9 | -10.4 13.3 295 19 10 5.9 3.2
21000 -8.1 17.4 295 17 9 5.1 2.8 | -8.4 16.9 295 18 9 5.5 3.0
20000 -6.7 19.9 295 16 8 5.2 2.8 | -6.8 19.8 295 16 8 5.7 3.1
19500 -5.9 21.4 295 16 8 5.5 3.0 | -6.0 21.2 295 16 8 6.2 3.4
19000 -5.1 22.8 290 15 8 6.3 3.5 | -5.0 23.0 295 15 8 6.8 3.8
18500 -4.2 24.4 290 15 8 6.3 3.5 | -4.1 24.6 295 15 8 6.8 3.7
18000 -3.2 26.2 290 15 7 6.8 3.8 | -3.0 26.6 295 14 7 8.1 4.4
17500 -2.2 28.0 290 14 7 6.9 3.8 | -1.9 28.6 295 14 7 8.1 4.4
17000 -1.2 29.8 285 14 7 7.3 4.0 | -0.7 30.7 290 13 7 8.5 4.7
16500 -0.1 31.8 285 13 7 8.1 4.5 | 0.6 33.1 290 13 7 9.1 5.0
16000 1.1 34.0 285 13 7 8.0 4.4 | 1.9 35.4 290 12 6 9.1 5.0
15500 2.4 36.3 280 12 6 9.2 5.0 | 3.3 37.9 290 12 6 9.5 5.2
15000 3.7 38.7 280 12 6 9.1 5.0 | 4.7 40.5 290 12 6 9.4 5.2
14500 5.1 41.2 275 12 6 9.2 5.1 | 6.1 43.0 285 12 6 9.5 5.2
14000 6.4 43.5 275 11 6 9.3 5.1 | 7.5 45.5 285 11 6 9.6 5.2
13500 7.8 46.0 275 11 6 9.5 5.2 | 9.0 48.2 285 11 6 9.5 5.2
13000 9.3 48.7 270 11 6 9.7 5.3 | 10.4 50.7 280 11 6 9.4 5.1
12500 10.7 51.3 270 11 6 9.7 5.3 | 11.8 53.2 280 11 6 9.4 5.2
12000 12.1 53.8 270 10 5 9.3 5.1 | 13.2 55.8 275 11 6 9.6 5.3
11500 13.6 56.5 265 10 5 9.2 5.1 | 14.6 58.3 275 11 5 9.4 5.2
11000 14.8 58.6 265 10 5 8.1 4.4 | 15.9 60.6 275 11 5 8.0 4.4
10500 16.0 60.8 265 10 5 12.6 6.9 | 17.0 62.6 270 11 5 12.3 6.8
10250 17.2 63.0 265 10 5 13.7 7.5 | 18.2 64.8 270 11 5 13.3 7.3
10000 17.9 64.2 260 10 5 8.3 4.6 | 18.9 66.0 270 10 5 8.2 4.5
9750 18.6 65.5 260 10 5 10.0 5.5 | 19.6 67.3 270 10 5 10.0 5.5
9500 19.3 66.7 260 10 5 8.5 4.6 | 20.3 68.5 270 10 5 8.1 4.4
9250 19.9 67.8 260 9 5 7.6 4.2 | 20.8 69.4 265 10 5 7.8 4.3
9000 20.5 68.9 260 9 5 9.7 5.3 | 21.5 70.7 265 10 5 10.1 5.5
8750 21.3 70.3 260 9 5 10.9 6.0 | 22.3 72.1 265 10 5 10.6 5.8
8500 22.1 71.8 260 9 5 10.4 5.7 | 23.1 73.6 265 10 5 10.3 5.7
8250 22.8 73.0 260 9 5 8.7 4.8 | 23.8 74.8 265 10 5 9.2 5.0
8000 24.3 75.7 260 9 4 11.3 6.2 | 24.5 76.1 265 10 5 9.4 5.2
7750 25.1 77.2 260 9 4 10.2 5.6 | 25.2 77.4 265 9 5 10.5 5.7
7500 25.8 78.4 260 8 4 8.7 4.8 | 26.7 80.1 265 9 5 9.1 5.0
7250 26.4 79.5 260 9 4 9.1 5.0 | 27.4 81.3 265 9 5 9.3 5.1
7000 27.2 81.0 260 8 4 11.2 6.1 | 28.1 82.6 265 9 5 10.3 5.7
6750 28.1 82.6 260 8 4 11.4 6.2 | 28.9 84.0 265 9 4 10.6 5.8
6500 28.9 84.0 260 8 4 11.0 6.0 | 29.7 85.5 265 8 4 10.6 5.8
6250 29.7 85.5 255 8 4 10.5 5.8 | 30.5 86.9 260 8 4 10.7 5.9
6000 30.5 86.9 255 8 4 10.6 5.8 | 31.2 88.2 260 8 4 8.4 4.6
5750 31.5 88.7 255 7 4 21.3 11.7 | 31.8 89.2 265 7 4 10.2 5.6
5500 34.4 93.9 255 7 3 62.0 34.0 | 33.6 92.5 260 7 3 47.5 26.1
5250 M M M M M M M | M M M M M M M
5000 M M M M M M M | M M M M M M M
________________________________________________________________________________

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 at Walker Field in Grand
Junction, Colorado at

North Latitude: 39 deg 07 min 00.001 sec
West Longitude: 108 deg 31 min 59.998 sec
Elevation: 4839 feet (1475 meters)

and may not be representative of other areas along the Western Slope of
Colorado. 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.

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