Grand Junction Soaring Forecast

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700
UXUS97 KGJT 301306
SRGGJT

Soaring Forecast
National Weather Service Grand Junction, Colorado
706 AM MDT Sunday, March 30, 2025

This forecast is for Sunday, March 30, 2025:

If the trigger temperature of 52.0 F/11.1 C is reached...then
Thermal Soaring Index....................... Good
Maximum rate of lift........................ 599 ft/min (3.0 m/s)
Maximum height of thermals.................. 16848 ft MSL (11242 ft AGL)

Forecast maximum temperature................... 62.0 F/17.1 C
Time of trigger temperature.................... 1045 MDT
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................. 13707 ft MSL (8101 ft AGL)
Thermal soaring outlook for Monday 03/31....... Excellent

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

Remarks...

Sunrise/Sunset.................... 07:00:46 / 19:36:03 MDT
Total possible sunshine........... 12 hr 35 min 17 sec (755 min 17 sec)
Altitude of sun at 13:18:24 MDT... 54.72 degrees

Upper air data from rawinsonde observation taken on 03/30/2025 at 0600 MDT

Freezing level.................. 9205 ft MSL (3599 ft AGL)
Convective condensation level... 12611 ft MSL (7005 ft AGL)
Lifted condensation level....... 14207 ft MSL (8601 ft AGL)
Lifted index.................... +0.4
K index......................... +10.0

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 -57.2 -71.0 270 44 22 -0.0 -0.0 M M M M M
45000 -57.2 -71.0 280 61 31 0.1 0.1 M M M M M
40000 -59.8 -75.6 280 87 45 -1.8 -1.0 M M M M M
38000 -59.8 -75.6 285 96 50 3.5 1.9 M M M M M
36000 -57.7 -71.9 285 102 53 3.5 1.9 M M M M M
34000 -55.6 -68.1 285 108 56 5.5 3.0 M M M M M
32000 -50.3 -58.5 285 100 52 7.9 4.4 M M M M M
30000 -45.4 -49.7 285 93 48 8.5 4.6 29.7 85.4 9.8 M M
29000 -42.9 -45.2 285 90 46 8.5 4.6 29.0 84.3 9.4 M M
28000 -40.4 -40.7 285 86 44 8.5 4.6 28.5 83.4 9.1 M M
27000 -37.9 -36.2 285 83 43 8.5 4.7 28.2 82.7 8.9 M M
26000 -35.7 -32.3 285 78 40 6.8 3.7 27.1 80.8 8.2 M M
25000 -33.7 -28.7 280 73 37 6.8 3.7 25.9 78.7 7.4 M M
24000 -31.7 -25.1 280 68 35 6.8 3.7 24.9 76.9 6.6 M M
23000 -29.8 -21.6 275 63 32 6.1 3.3 23.6 74.5 5.7 M M
22000 -28.0 -18.4 275 58 30 6.1 3.3 22.3 72.1 4.6 M M
21000 -26.2 -15.2 275 53 27 6.2 3.4 21.0 69.9 3.6 M M
20000 -24.1 -11.4 270 47 24 7.1 3.9 20.0 68.0 2.8 M M
19500 -23.0 -9.4 270 45 23 7.1 3.9 19.5 67.1 2.4 M M
19000 -21.4 -6.5 270 41 21 7.1 3.9 18.8 65.9 1.9 M M
18500 -20.3 -4.5 265 38 20 6.9 3.8 18.4 65.2 1.5 M M
18000 -19.3 -2.7 265 36 19 6.8 3.8 17.9 64.2 1.1 M M
17500 -18.3 -0.9 265 34 17 6.8 3.7 17.4 63.4 0.6 M M
17000 -17.4 0.7 265 32 16 5.9 3.2 16.8 62.3 0.1 M M
16500 -16.5 2.3 265 30 15 5.9 3.3 16.2 61.1 -0.5 963 4.9
16000 -15.6 3.9 260 28 14 6.5 3.6 15.6 60.0 -1.1 921 4.7
15500 -14.7 5.5 260 27 14 6.6 3.6 15.0 59.1 -1.6 878 4.5
15000 -13.7 7.3 260 25 13 7.2 3.9 14.5 58.2 -2.1 834 4.2
14500 -12.6 9.3 260 24 13 7.6 4.2 14.2 57.5 -2.5 786 4.0
14000 -11.5 11.3 260 23 12 7.8 4.3 13.8 56.9 -2.8 738 3.8
13500 -10.3 13.5 260 23 12 8.2 4.5 13.5 56.4 -3.1 688 3.5
13000 -9.1 15.6 260 22 11 8.4 4.6 13.3 56.0 -3.4 638 3.2
12500 -7.8 18.0 255 21 11 8.9 4.9 13.1 55.6 -3.6 585 3.0
12000 -6.5 20.3 255 21 11 8.8 4.9 13.0 55.4 -3.8 531 2.7
11500 -5.2 22.6 250 20 10 8.7 4.8 12.8 55.1 -4.0 477 2.4
11000 -3.9 25.0 250 19 10 8.3 4.6 12.7 54.8 -4.2 424 2.2
10500 -2.9 26.8 245 17 9 6.6 3.6 12.3 54.1 -4.6 378 1.9
10250 -2.4 27.7 245 17 9 8.4 4.6 12.1 53.8 -4.8 354 1.8
10000 -1.7 28.9 240 16 8 8.4 4.6 12.0 53.6 -4.9 327 1.7
9750 -1.2 29.8 235 15 8 6.8 3.7 11.8 53.3 -5.1 304 1.5
9500 -0.7 30.7 235 14 7 6.4 3.5 11.6 52.9 -5.4 282 1.4
9250 -0.2 31.6 230 12 6 7.8 4.3 11.4 52.4 -5.6 260 1.3
9000 0.4 32.7 220 12 6 7.3 4.0 11.2 52.2 -5.8 235 1.2
8750 0.8 33.4 215 11 6 5.6 3.1 10.9 51.7 -6.1 214 1.1
8500 1.3 34.3 205 11 6 6.1 3.3 10.6 51.2 -6.4 194 1.0
8250 1.7 35.1 195 11 5 5.9 3.2 10.4 50.7 -6.7 173 0.9
8000 2.1 35.8 190 11 6 5.5 3.0 10.1 50.1 -7.0 153 0.8
7750 2.5 36.5 185 11 6 5.2 2.8 9.7 49.5 -7.4 134 0.7
7500 2.9 37.2 180 12 6 5.6 3.1 9.4 48.9 -7.7 115 0.6
7250 3.3 37.9 170 12 6 4.2 2.3 9.0 48.3 -8.1 96 0.5
7000 3.6 38.5 165 14 7 3.5 1.9 8.6 47.4 -8.6 81 0.4
6750 3.9 39.0 160 13 7 4.5 2.5 8.1 46.6 -9.0 64 0.3
6500 4.2 39.6 155 13 7 3.8 2.1 7.7 45.9 -9.5 47 0.2
6250 4.3 39.7 150 12 6 -0.5 -0.2 7.1 44.9 -10.1 35 0.2
6000 4.2 39.6 145 11 5 0.3 0.2 6.3 43.4 -10.9 31 0.2
5750 4.3 39.7 140 9 5 -1.2 -0.7 5.7 42.2 -11.6 22 0.1
5500 M M M M M M M M M M M M
5250 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

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

03/30/2025 at 0900 MDT | 03/30/2025 at 1200 MDT
|
CAPE... 0.0 LI... +4.6 | CAPE... +0.1 LI... +3.1
CINH... -1.8 K Index... -6.0 | CINH... -2.8 K Index... +9.6
|
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 -56.7 -70.1 270 44 23 2.7 1.5 | -56.7 -70.1 265 42 22 2.7 1.5
45000 -52.7 -62.9 270 55 28 3.0 1.6 | -52.8 -63.0 260 52 27 2.8 1.5
40000 -53.4 -64.1 275 60 31 -0.7 -0.4 | -52.0 -61.6 260 60 31 0.4 0.2
38000 -54.1 -65.4 270 62 32 -1.6 -0.9 | -52.5 -62.5 260 60 31 -3.4 -1.9
36000 -55.0 -67.0 265 66 34 -1.6 -0.9 | -54.5 -66.1 250 56 29 -3.4 -1.9
34000 -56.0 -68.8 260 70 36 2.6 1.4 | -56.6 -69.9 240 53 28 0.1 0.1
32000 -51.7 -61.1 260 65 34 7.2 3.9 | -52.4 -62.3 240 50 26 7.4 4.0
30000 -47.3 -53.1 260 61 31 8.5 4.6 | -47.9 -54.2 240 47 24 8.4 4.6
29000 -44.7 -48.5 265 58 30 8.9 4.9 | -45.3 -49.5 245 45 23 9.0 4.9
28000 -42.0 -43.6 265 54 28 8.9 4.9 | -42.6 -44.7 250 43 22 9.0 4.9
27000 -39.4 -38.9 270 51 26 8.9 4.9 | -39.9 -39.8 255 41 21 9.0 4.9
26000 -36.9 -34.4 270 48 25 7.7 4.2 | -37.4 -35.3 255 39 20 7.8 4.3
25000 -34.6 -30.3 270 44 23 7.7 4.2 | -35.1 -31.2 260 37 19 7.8 4.3
24000 -32.3 -26.1 270 40 21 7.7 4.2 | -32.7 -26.9 260 36 18 7.8 4.3
23000 -29.8 -21.6 265 36 19 6.1 3.3 | -30.0 -22.0 260 34 18 6.7 3.7
22000 -28.0 -18.4 265 34 17 6.1 3.3 | -28.0 -18.4 255 33 17 6.7 3.7
21000 -26.2 -15.2 260 31 16 6.3 3.5 | -26.0 -14.8 255 33 17 6.5 3.5
20000 -24.1 -11.4 260 31 16 6.8 3.8 | -24.4 -11.9 250 31 16 5.5 3.0
19500 -23.1 -9.6 260 31 16 6.8 3.8 | -23.6 -10.5 250 29 15 5.5 3.0
19000 -22.1 -7.8 265 31 16 6.8 3.8 | -22.8 -9.0 245 28 15 5.5 3.0
18500 -21.0 -5.8 265 31 16 6.9 3.8 | -22.0 -7.6 245 27 14 5.5 3.0
18000 -20.0 -4.0 265 31 16 7.3 4.0 | -21.2 -6.2 245 26 14 5.1 2.8
17500 -18.9 -2.0 265 31 16 7.3 4.0 | -20.4 -4.7 245 25 13 5.1 2.8
17000 -17.8 -0.0 265 31 16 7.1 3.9 | -19.6 -3.3 250 25 13 5.6 3.0
16500 -16.7 1.9 270 31 16 7.0 3.9 | -18.8 -1.8 250 24 13 5.7 3.1
16000 -15.6 3.9 270 30 16 6.5 3.6 | -17.9 -0.2 250 24 12 6.1 3.3
15500 -14.7 5.5 270 29 15 5.9 3.3 | -16.9 1.6 255 24 12 6.7 3.7
15000 -13.8 7.2 270 28 14 5.7 3.1 | -15.9 3.4 255 23 12 6.8 3.7
14500 -13.1 8.4 270 26 13 4.8 2.6 | -14.9 5.2 255 23 12 7.1 3.9
14000 -12.4 9.7 265 24 12 4.9 2.7 | -13.8 7.2 255 23 12 7.1 3.9
13500 -11.7 10.9 265 21 11 4.8 2.7 | -12.7 9.1 255 22 12 7.7 4.2
13000 -11.0 12.2 260 19 10 4.8 2.6 | -11.6 11.1 255 22 11 7.6 4.2
12500 -10.2 13.6 255 17 9 6.1 3.3 | -10.4 13.3 255 21 11 7.8 4.3
12000 -9.3 15.3 255 15 8 6.0 3.3 | -9.3 15.3 255 20 10 7.8 4.3
11500 -8.5 16.7 250 14 7 6.4 3.5 | -8.1 17.4 250 19 10 7.5 4.1
11000 -7.5 18.5 245 12 6 6.6 3.6 | -7.0 19.4 245 17 9 7.7 4.2
10500 -6.8 19.8 235 11 6 4.3 2.4 | -6.0 21.2 245 16 8 6.3 3.5
10250 -6.5 20.3 235 11 6 3.4 1.9 | -5.6 21.9 240 15 8 5.6 3.1
10000 -6.2 20.8 230 11 6 8.1 4.4 | -5.1 22.8 240 15 8 9.8 5.4
9750 -5.4 22.3 230 10 5 10.1 5.6 | -4.3 24.3 235 13 6 9.8 5.4
9500 -4.9 23.2 225 9 5 6.8 3.7 | -3.8 25.2 235 12 6 5.9 3.2
9250 -4.3 24.3 225 9 5 8.1 4.5 | -3.3 26.1 230 11 6 6.4 3.5
9000 -3.8 25.2 220 9 4 6.2 3.4 | -2.8 27.0 230 10 5 8.4 4.6
8750 -2.7 27.1 220 8 4 8.8 4.8 | -2.1 28.2 225 9 4 9.4 5.2
8500 -2.1 28.2 220 7 4 8.6 4.7 | -1.0 30.2 220 7 4 8.6 4.7
8250 -1.5 29.3 220 7 4 7.6 4.2 | -0.4 31.3 220 6 3 5.8 3.2
8000 -1.0 30.2 225 7 3 7.4 4.0 | -0.0 32.0 220 5 3 7.3 4.0
7750 -0.4 31.3 225 6 3 8.4 4.6 | 0.7 33.3 220 5 3 11.2 6.2
7500 0.2 32.4 225 6 3 7.8 4.3 | 1.5 34.7 220 5 3 9.8 5.4
7250 0.8 33.4 230 6 3 6.2 3.4 | 2.2 36.0 225 5 2 6.6 3.6
7000 1.2 34.2 235 5 3 7.4 4.0 | 2.6 36.7 225 4 2 8.8 4.8
6750 1.9 35.4 235 5 2 9.3 5.1 | 3.5 38.3 225 4 2 13.1 7.2
6500 2.5 36.5 235 4 2 8.4 4.6 | 4.4 39.9 225 4 2 10.6 5.8
6250 3.2 37.8 240 3 2 8.5 4.7 | 5.1 41.2 230 4 2 9.7 5.3
6000 3.8 38.8 250 3 1 7.6 4.2 | 5.9 42.6 235 3 2 8.8 4.8
5750 4.3 39.7 240 3 2 9.4 5.1 | 6.6 43.9 230 4 2 13.0 7.2
5500 5.7 42.3 260 2 1 35.1 19.3 | 8.8 47.8 240 3 2 56.3 30.9
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

03/30/2025 at 1500 MDT | 03/30/2025 at 1800 MDT
|
CAPE... +10.3 LI... +1.7 | CAPE... +1.0 LI... +1.2
CINH... -3.1 K Index... +17.1 | CINH... -4.6 K Index... +18.6
|
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 -56.4 -69.5 265 39 20 2.7 1.5 | -56.3 -69.3 270 40 21 2.9 1.6
45000 -52.4 -62.3 265 51 26 2.9 1.6 | -52.0 -61.6 270 50 26 3.0 1.7
40000 -51.9 -61.4 265 53 27 0.1 0.1 | -52.5 -62.5 275 52 27 -0.6 -0.3
38000 -52.3 -62.1 260 52 27 -2.1 -1.1 | -52.9 -63.2 275 51 26 -0.7 -0.4
36000 -53.5 -64.3 260 49 25 -2.1 -1.1 | -53.4 -64.1 275 48 25 -0.7 -0.4
34000 -54.8 -66.6 250 46 24 -0.5 -0.3 | -53.8 -64.8 275 46 24 0.0 0.0
32000 -52.1 -61.8 245 45 23 4.8 2.6 | -52.0 -61.6 275 40 21 3.3 1.8
30000 -49.2 -56.6 240 45 23 6.7 3.7 | -50.0 -58.0 270 34 18 5.2 2.9
29000 -46.6 -51.9 240 43 22 8.9 4.9 | -47.7 -53.9 270 34 17 8.1 4.5
28000 -44.0 -47.2 245 41 21 8.9 4.9 | -45.2 -49.4 270 33 17 8.1 4.5
27000 -41.3 -42.3 250 39 20 8.9 4.9 | -42.8 -45.0 265 33 17 8.1 4.5
26000 -38.7 -37.7 255 37 19 8.4 4.6 | -40.3 -40.5 265 32 17 8.7 4.8
25000 -36.2 -33.2 255 34 18 8.4 4.6 | -37.6 -35.7 270 33 17 8.8 4.8
24000 -33.7 -28.7 260 31 16 8.4 4.6 | -35.0 -31.0 270 33 17 8.7 4.8
23000 -30.8 -23.4 260 30 15 7.2 3.9 | -32.0 -25.6 275 32 16 7.6 4.2
22000 -28.7 -19.7 265 29 15 7.2 3.9 | -29.7 -21.5 275 30 15 7.6 4.2
21000 -26.6 -15.9 265 29 15 6.7 3.7 | -27.5 -17.5 280 28 14 7.3 4.0
20000 -24.9 -12.8 260 27 14 5.3 2.9 | -25.5 -13.9 280 26 14 6.5 3.6
19500 -24.1 -11.4 260 27 14 5.3 2.9 | -24.5 -12.1 280 26 13 6.5 3.6
19000 -23.4 -10.1 255 26 13 5.3 2.9 | -23.6 -10.5 280 25 13 6.5 3.6
18500 -22.6 -8.7 250 25 13 5.4 3.0 | -22.6 -8.7 285 24 12 6.5 3.6
18000 -21.7 -7.1 250 24 12 6.2 3.4 | -21.6 -6.9 280 24 12 6.5 3.6
17500 -20.8 -5.4 245 23 12 6.1 3.4 | -20.7 -5.3 280 23 12 6.5 3.6
17000 -19.9 -3.8 245 21 11 6.3 3.4 | -19.7 -3.5 280 23 12 7.0 3.9
16500 -18.9 -2.0 245 20 10 6.3 3.5 | -18.6 -1.5 275 22 11 7.1 3.9
16000 -18.0 -0.4 245 19 10 6.4 3.5 | -17.6 0.3 275 22 11 7.0 3.8
15500 -17.0 1.4 245 18 9 6.6 3.6 | -16.6 2.1 270 21 11 7.0 3.8
15000 -16.1 3.0 245 17 9 6.7 3.7 | -15.5 4.1 265 20 10 7.0 3.9
14500 -15.0 5.0 245 16 8 7.1 3.9 | -14.5 5.9 265 19 10 7.3 4.0
14000 -14.0 6.8 245 16 8 7.1 3.9 | -13.4 7.9 260 18 9 7.4 4.0
13500 -12.9 8.8 245 16 8 7.8 4.3 | -12.2 10.0 260 18 9 8.1 4.4
13000 -11.8 10.8 250 16 8 7.7 4.2 | -11.1 12.0 255 18 9 8.0 4.4
12500 -10.6 12.9 250 16 8 8.3 4.6 | -9.8 14.4 255 17 9 8.7 4.7
12000 -9.3 15.3 250 16 8 8.3 4.5 | -8.6 16.5 255 17 9 8.6 4.7
11500 -8.1 17.4 250 16 8 8.4 4.6 | -7.3 18.9 250 17 9 8.7 4.8
11000 -6.9 19.6 250 16 8 8.5 4.6 | -6.0 21.2 250 17 9 8.7 4.8
10500 -5.7 21.7 250 15 8 7.3 4.0 | -4.8 23.4 250 16 8 7.6 4.2
10250 -5.2 22.6 250 15 8 7.3 4.0 | -4.2 24.4 250 16 8 7.8 4.3
10000 -4.6 23.7 250 15 8 10.6 5.8 | -3.6 25.5 250 15 8 10.3 5.6
9750 -3.7 25.3 250 14 7 11.1 6.1 | -2.8 27.0 245 15 8 10.3 5.7
9500 -3.0 26.6 250 14 7 8.9 4.9 | -2.1 28.2 245 15 8 8.6 4.7
9250 -2.3 27.9 250 14 7 9.2 5.0 | -1.4 29.5 245 14 7 8.9 4.9
9000 -1.6 29.1 250 13 7 10.3 5.6 | -0.8 30.6 245 14 7 9.6 5.3
8750 -0.7 30.7 250 13 7 10.7 5.9 | -0.0 32.0 245 14 7 10.0 5.5
8500 0.7 33.3 250 13 6 10.1 5.6 | 0.7 33.3 240 13 7 9.4 5.1
8250 1.5 34.7 250 12 6 9.2 5.0 | 2.1 35.8 240 13 7 9.6 5.3
8000 2.1 35.8 255 13 7 9.5 5.2 | 2.8 37.0 240 12 6 9.6 5.3
7750 2.9 37.2 255 12 6 10.8 5.9 | 3.5 38.3 240 12 6 9.5 5.2
7500 3.7 38.7 250 12 6 10.1 5.5 | 4.3 39.7 240 12 6 9.4 5.2
7250 4.4 39.9 255 12 6 7.9 4.3 | 4.9 40.8 240 12 6 8.4 4.6
7000 5.0 41.0 255 12 6 9.4 5.1 | 5.6 42.1 240 12 6 9.4 5.1
6750 5.8 42.4 255 11 6 11.8 6.5 | 6.3 43.3 240 12 6 10.6 5.8
6500 6.6 43.9 255 11 6 10.8 5.9 | 7.1 44.8 235 11 6 10.4 5.7
6250 7.5 45.5 255 11 6 11.5 6.3 | 7.9 46.2 235 11 6 11.5 6.3
6000 8.3 46.9 260 11 6 8.5 4.7 | 8.7 47.7 240 11 6 8.6 4.7
5750 8.9 48.0 255 10 5 11.4 6.2 | 9.3 48.7 235 10 5 7.9 4.3
5500 11.5 52.7 260 10 5 74.4 40.8 | 10.9 51.6 235 9 5 48.4 26.6
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
________________________________________________________________________________

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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