Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
726
UXUS97 KGJT 031307
SRGGJT
Soaring Forecast
National Weather Service Grand Junction, Colorado
707 AM MDT Wednesday, July 3, 2024
This forecast is for Wednesday, July 3, 2024:
If the trigger temperature of 81.7 F/27.6 C is reached...then
Thermal Soaring Index....................... Excellent
Maximum rate of lift........................ 1113 ft/min (5.7 m/s)
Maximum height of thermals.................. 17289 ft MSL (12450 ft AGL)
Forecast maximum temperature................... 92.0 F/33.8 C
Time of trigger temperature.................... 1100 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................. 12665 ft MSL (7826 ft AGL)
Thermal soaring outlook for Thursday 07/04..... Excellent
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 05:53:20 / 20:43:45 MDT
Total possible sunshine........... 14 hr 50 min 25 sec (890 min 25 sec)
Altitude of sun at 13:18:33 MDT... 73.28 degrees
Upper air data from rawinsonde observation taken on 07/03/2024 at 0600 MDT
Freezing level.................. 15455 ft MSL (10616 ft AGL)
Convective condensation level... 20507 ft MSL (15668 ft AGL)
Lifted condensation level....... 20072 ft MSL (15233 ft AGL)
Lifted index.................... +0.5
K index......................... +0.2
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 -60.0 -76.0 280 52 27 -1.8 -1.0 93.4 200.1 34.9 M M
45000 -54.9 -66.8 260 59 30 4.3 2.3 77.5 171.5 27.5 M M
40000 -45.8 -50.4 250 60 31 5.3 2.9 67.9 154.3 23.1 M M
38000 -44.1 -47.4 255 47 24 5.2 2.9 61.8 143.3 19.5 M M
36000 -40.8 -41.4 260 48 25 2.3 1.3 58.2 136.8 17.4 M M
34000 -37.5 -35.5 260 45 23 5.7 3.1 54.6 130.2 15.3 M M
32000 -34.1 -29.4 250 47 24 5.7 3.2 51.3 124.3 13.2 M M
30000 -30.7 -23.3 270 47 24 3.9 2.1 47.0 116.6 10.4 M M
29000 -30.1 -22.2 275 45 23 -0.3 -0.2 44.0 111.1 8.1 M M
28000 -29.1 -20.4 270 38 20 3.5 1.9 41.4 106.6 6.3 M M
27000 -28.1 -18.6 265 37 19 5.9 3.2 39.0 102.2 4.4 M M
26000 -25.3 -13.5 260 35 18 9.8 5.4 38.9 102.0 4.4 M M
25000 -22.4 -8.3 260 34 18 8.9 4.9 38.9 102.0 4.4 M M
24000 -20.7 -5.3 260 34 17 7.8 4.3 37.4 99.4 3.2 M M
23000 -18.0 -0.4 260 29 15 9.2 5.1 37.2 99.0 3.1 M M
22000 -15.8 3.6 255 28 15 6.6 3.6 36.4 97.5 2.4 M M
21000 -13.6 7.5 250 29 15 8.2 4.5 35.6 96.0 1.7 M M
20000 -11.1 12.0 255 30 15 8.3 4.6 35.0 95.1 1.3 M M
19500 -9.8 14.4 260 29 15 9.1 5.0 34.8 94.6 1.1 M M
19000 -8.4 16.9 265 31 16 8.6 4.7 34.7 94.5 1.0 M M
18500 -7.1 19.2 260 32 16 8.5 4.7 34.5 94.1 0.9 M M
18000 -5.9 21.4 265 35 18 8.3 4.6 34.3 93.7 0.7 M M
17500 -4.8 23.4 265 38 20 7.1 3.9 33.9 93.0 0.3 M M
17000 -3.8 25.2 265 41 21 7.7 4.2 33.5 92.3 -0.2 1097 5.6
16500 -2.2 28.0 260 39 20 7.2 3.9 32.9 91.2 -0.7 1026 5.2
16000 -1.0 30.2 260 37 19 7.2 3.9 32.4 90.4 -1.0 977 5.0
15500 0.1 32.2 265 34 17 6.2 3.4 32.0 89.7 -1.3 927 4.7
15000 1.0 33.8 275 30 16 6.9 3.8 31.3 88.4 -2.0 888 4.5
14500 2.1 35.8 280 28 14 7.9 4.3 31.0 87.8 -2.3 840 4.3
14000 3.4 38.1 285 27 14 8.4 4.6 30.8 87.4 -2.5 787 4.0
13500 4.6 40.3 285 25 13 8.4 4.6 30.5 87.0 -2.7 733 3.7
13000 5.9 42.6 280 23 12 8.6 4.7 30.3 86.6 -2.9 680 3.5
12500 7.1 44.8 280 21 11 7.5 4.1 30.0 86.1 -3.2 630 3.2
12000 8.1 46.6 270 17 9 8.2 4.5 29.7 85.5 -3.6 585 3.0
11500 9.3 48.7 270 15 8 9.4 5.1 29.6 85.3 -3.9 533 2.7
11000 10.7 51.3 270 14 7 9.2 5.1 29.5 85.2 -4.0 477 2.4
10500 12.1 53.8 275 7 4 8.6 4.7 29.5 85.0 -4.1 422 2.1
10250 12.6 54.7 280 4 2 6.5 3.6 29.3 84.7 -4.3 398 2.0
10000 13.1 55.6 285 1 1 5.7 3.1 29.0 84.2 -4.6 377 1.9
9750 13.5 56.3 295 1 0 6.2 3.4 28.7 83.6 -4.9 356 1.8
9500 14.0 57.2 070 2 1 7.4 4.1 28.4 83.2 -5.1 334 1.7
9250 14.6 58.3 080 4 2 8.1 4.5 28.3 83.0 -5.3 308 1.6
9000 15.2 59.4 080 6 3 7.9 4.4 28.2 82.7 -5.4 283 1.4
8750 15.8 60.4 080 5 3 8.0 4.4 28.0 82.5 -5.5 258 1.3
8500 16.4 61.5 075 6 3 8.0 4.4 27.9 82.2 -5.7 232 1.2
8250 17.0 62.6 065 4 2 8.0 4.4 27.8 82.0 -5.8 207 1.1
8000 17.6 63.7 040 3 2 7.8 4.3 27.6 81.7 -6.0 182 0.9
7750 18.2 64.8 035 2 1 6.9 3.8 27.4 81.4 -6.2 158 0.8
7500 18.6 65.5 000 0 0 6.5 3.6 27.2 81.0 -6.5 137 0.7
7250 19.1 66.4 115 2 1 6.6 3.6 27.0 80.5 -6.8 116 0.6
7000 19.6 67.3 115 5 2 7.7 4.2 26.7 80.1 -7.0 94 0.5
6750 20.1 68.2 120 7 3 4.6 2.5 26.5 79.8 -7.2 70 0.4
6500 20.2 68.4 125 10 5 -0.1 -0.0 25.9 78.7 -7.9 60 0.3
6250 20.2 68.4 125 13 7 2.4 1.3 25.2 77.4 -8.6 53 0.3
6000 20.5 68.9 130 16 8 3.7 2.0 24.8 76.6 -9.1 38 0.2
5750 20.7 69.3 135 15 7 6.4 3.5 24.3 75.8 -9.6 23 0.1
5500 21.0 69.8 130 14 7 -5.0 -2.8 23.9 75.1 -10.1 8 0.0
5250 19.8 67.6 130 13 7 -19.9 -10.9 22.0 71.7 -12.1 36 0.2
5000 18.4 65.1 125 14 7 -14.6 -8.0 20.0 67.9 -14.2 70 0.4
* * * * * * Numerical weather prediction model forecast data valid * * * * * *
07/03/2024 at 0900 MDT | 07/03/2024 at 1200 MDT
|
CAPE... 0.0 LI... +3.5 | CAPE... 0.0 LI... +2.9
CINH... -0.0 K Index... +7.1 | CINH... -0.0 K Index... +9.7
|
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 -60.5 -76.9 270 40 20 3.0 1.6 | -60.7 -77.3 265 49 25 2.3 1.3
45000 -54.4 -65.9 270 53 27 6.3 3.5 | -55.3 -67.5 270 59 30 6.4 3.5
40000 -45.0 -49.0 270 57 29 3.8 2.1 | -45.7 -50.3 270 53 27 3.7 2.0
38000 -42.7 -44.9 270 51 26 3.8 2.1 | -43.5 -46.3 275 53 27 3.7 2.0
36000 -40.4 -40.7 270 46 24 3.7 2.0 | -41.2 -42.2 280 52 27 3.5 1.9
34000 -37.7 -35.9 270 41 21 4.6 2.5 | -38.2 -36.8 290 46 24 5.3 2.9
32000 -35.0 -31.0 270 37 19 4.7 2.6 | -35.0 -31.0 300 40 21 5.3 2.9
30000 -31.9 -25.4 275 34 18 5.3 2.9 | -31.2 -24.2 300 38 20 6.7 3.7
29000 -30.3 -22.5 275 33 17 5.3 2.9 | -29.2 -20.6 300 38 19 6.7 3.7
28000 -28.7 -19.7 280 32 16 5.4 2.9 | -27.2 -17.0 300 37 19 6.5 3.6
27000 -26.9 -16.4 280 32 17 6.2 3.4 | -25.5 -13.9 295 37 19 5.2 2.9
26000 -25.1 -13.2 275 33 17 6.2 3.4 | -24.0 -11.2 290 36 19 5.2 2.9
25000 -23.2 -9.8 275 34 17 6.1 3.4 | -22.4 -8.3 290 36 18 5.1 2.8
24000 -20.5 -4.9 270 34 17 7.5 4.1 | -19.9 -3.8 285 34 18 7.2 4.0
23000 -18.3 -0.9 265 33 17 7.5 4.1 | -17.8 -0.0 280 33 17 7.2 4.0
22000 -16.1 3.0 260 33 17 7.6 4.2 | -15.6 3.9 280 32 16 7.2 4.0
21000 -13.8 7.2 260 32 17 7.8 4.3 | -13.5 7.7 275 32 16 7.3 4.0
20000 -11.5 11.3 260 31 16 7.8 4.3 | -11.3 11.7 270 32 16 7.4 4.1
19500 -10.3 13.5 260 31 16 7.9 4.3 | -10.2 13.6 270 32 16 7.4 4.1
19000 -9.2 15.4 260 30 16 7.4 4.1 | -9.1 15.6 265 32 16 7.7 4.2
18500 -8.1 17.4 260 30 15 7.5 4.1 | -8.0 17.6 265 32 16 7.7 4.2
18000 -7.0 19.4 265 29 15 7.8 4.3 | -6.8 19.8 265 31 16 8.0 4.4
17500 -5.8 21.6 265 29 15 8.1 4.5 | -5.6 21.9 265 31 16 8.2 4.5
17000 -4.6 23.7 265 28 14 8.1 4.5 | -4.4 24.1 265 30 15 8.2 4.5
16500 -3.4 25.9 265 27 14 8.2 4.5 | -3.2 26.2 260 29 15 8.2 4.5
16000 -2.1 28.2 265 27 14 8.2 4.5 | -2.0 28.4 265 28 15 8.2 4.5
15500 -0.9 30.4 265 26 13 8.2 4.5 | -0.8 30.6 265 28 14 8.3 4.5
15000 0.3 32.5 265 25 13 8.2 4.5 | 0.4 32.7 265 27 14 8.3 4.6
14500 1.5 34.7 265 24 12 8.2 4.5 | 1.6 34.9 265 26 13 8.3 4.6
14000 2.7 36.9 265 23 12 8.3 4.6 | 2.9 37.2 265 25 13 8.4 4.6
13500 4.0 39.2 265 22 11 8.3 4.6 | 4.1 39.4 265 23 12 8.4 4.6
13000 5.2 41.4 265 20 11 8.4 4.6 | 5.4 41.7 265 22 11 8.5 4.7
12500 6.5 43.7 265 19 10 8.4 4.6 | 6.6 43.9 265 20 11 8.5 4.7
12000 7.7 45.9 270 18 9 8.1 4.5 | 7.9 46.2 265 19 10 8.8 4.8
11500 8.9 48.0 275 16 8 8.1 4.5 | 9.2 48.6 265 18 9 8.8 4.8
11000 10.1 50.2 275 15 8 7.8 4.3 | 10.4 50.7 265 16 8 7.9 4.3
10500 11.3 52.3 280 14 7 6.7 3.7 | 11.6 52.9 265 16 8 10.0 5.5
10250 11.7 53.1 280 14 7 6.2 3.4 | 12.4 54.3 270 14 7 10.5 5.8
10000 12.3 54.1 285 13 7 8.2 4.5 | 13.1 55.6 270 14 7 8.1 4.4
9750 12.9 55.2 285 12 6 8.3 4.6 | 13.7 56.7 270 13 7 8.7 4.8
9500 13.5 56.3 285 11 6 8.3 4.5 | 14.4 57.9 270 13 7 8.5 4.7
9250 14.1 57.4 285 10 5 7.4 4.0 | 15.0 59.0 270 12 6 7.7 4.2
9000 14.6 58.3 280 9 5 6.7 3.7 | 15.5 59.9 270 11 6 8.1 4.5
8750 15.1 59.2 280 8 4 6.9 3.8 | 16.2 61.2 270 11 5 9.1 5.0
8500 16.0 60.8 270 6 3 5.4 2.9 | 17.4 63.3 270 9 5 6.2 3.4
8250 16.4 61.5 265 5 3 5.2 2.8 | 17.9 64.2 275 9 4 8.0 4.4
8000 16.8 62.2 255 4 2 6.4 3.5 | 18.7 65.7 275 8 4 12.1 6.7
7750 17.3 63.1 240 3 2 5.2 2.8 | 19.5 67.1 275 7 4 10.4 5.7
7500 17.6 63.7 225 2 1 2.8 1.6 | 20.2 68.4 275 7 4 7.5 4.1
7250 17.8 64.0 215 2 1 3.2 1.7 | 20.7 69.3 275 7 4 8.0 4.4
7000 18.1 64.6 195 2 1 8.6 4.7 | 21.5 70.7 275 7 4 13.2 7.2
6750 18.9 66.0 155 1 1 8.2 4.5 | 22.6 72.7 275 6 3 12.5 6.9
6500 19.3 66.7 135 1 1 4.9 2.7 | 23.3 73.9 275 6 3 9.6 5.3
6250 19.6 67.3 120 2 1 5.1 2.8 | 24.1 75.4 280 6 3 9.5 5.2
6000 20.1 68.2 110 2 1 9.7 5.3 | 24.8 76.6 280 6 3 12.1 6.6
5750 21.2 70.2 110 2 1 21.1 11.6 | 26.1 79.0 280 5 3 24.4 13.4
5500 22.5 72.5 105 2 1 4.1 2.2 | 28.3 82.9 285 5 3 34.4 18.9
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
07/03/2024 at 1500 MDT | 07/03/2024 at 1800 MDT
|
CAPE... 0.0 LI... +1.9 | CAPE... 0.0 LI... +0.7
CINH... -0.0 K Index... +8.1 | CINH... 0.0 K Index... +11.8
|
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 -60.6 -77.1 265 46 24 2.8 1.5 | -60.9 -77.6 275 44 23 3.5 1.9
45000 -55.3 -67.5 275 58 30 5.1 2.8 | -55.4 -67.7 275 57 29 4.1 2.2
40000 -47.5 -53.5 280 64 33 3.9 2.2 | -48.8 -55.8 280 68 35 4.9 2.7
38000 -45.1 -49.2 285 59 30 3.9 2.2 | -45.9 -50.6 285 63 32 4.9 2.7
36000 -42.7 -44.9 290 54 28 3.7 2.0 | -42.9 -45.2 290 59 30 4.8 2.6
34000 -39.1 -38.4 295 52 27 6.4 3.5 | -39.2 -38.6 295 58 30 6.5 3.6
32000 -35.3 -31.5 305 51 26 6.3 3.5 | -35.3 -31.5 300 59 30 6.4 3.5
30000 -31.1 -24.0 305 48 25 7.2 4.0 | -30.8 -23.4 300 56 29 7.6 4.2
29000 -28.9 -20.0 305 45 23 7.2 4.0 | -28.5 -19.3 300 54 28 7.6 4.2
28000 -26.7 -16.1 305 43 22 7.3 4.0 | -26.2 -15.2 300 53 27 7.4 4.1
27000 -24.5 -12.1 300 42 21 7.3 4.0 | -24.1 -11.4 300 50 26 7.2 3.9
26000 -22.3 -8.1 295 41 21 7.3 4.0 | -21.9 -7.4 295 47 24 7.2 3.9
25000 -19.6 -3.3 285 40 21 6.8 3.7 | -19.8 -3.6 295 45 23 7.3 4.0
24000 -17.8 -0.0 285 38 20 5.8 3.2 | -17.3 0.9 295 43 22 6.6 3.6
23000 -16.1 3.0 285 36 19 5.8 3.2 | -15.3 4.5 290 42 22 6.6 3.6
22000 -14.4 6.1 285 35 18 6.1 3.4 | -13.3 8.1 290 41 21 5.7 3.1
21000 -12.4 9.7 280 32 16 6.5 3.6 | -11.9 10.6 290 37 19 5.0 2.7
20000 -10.5 13.1 280 30 15 6.5 3.6 | -10.4 13.3 290 33 17 5.1 2.8
19500 -9.5 14.9 275 28 15 6.6 3.6 | -9.7 14.5 290 31 16 5.4 3.0
19000 -8.6 16.5 275 27 14 6.3 3.5 | -8.7 16.3 290 30 15 8.2 4.5
18500 -7.7 18.1 275 26 14 6.4 3.5 | -7.6 18.3 290 28 14 8.0 4.4
18000 -6.7 19.9 275 25 13 7.5 4.1 | -6.4 20.5 290 27 14 8.6 4.7
17500 -5.6 21.9 275 25 13 8.0 4.4 | -5.1 22.8 285 26 13 8.9 4.9
17000 -4.4 24.1 270 24 12 8.2 4.5 | -3.8 25.2 285 25 13 9.0 4.9
16500 -3.1 26.4 270 24 12 9.1 5.0 | -2.4 27.7 285 24 13 9.5 5.2
16000 -1.7 28.9 270 23 12 9.0 4.9 | -1.0 30.2 285 24 12 9.4 5.2
15500 -0.4 31.3 270 23 12 9.1 5.0 | 0.4 32.7 285 23 12 9.6 5.2
15000 0.9 33.6 270 22 12 9.1 5.0 | 1.9 35.4 285 23 12 9.6 5.2
14500 2.3 36.1 270 22 11 9.1 5.0 | 3.3 37.9 285 23 12 9.6 5.3
14000 3.6 38.5 270 22 11 9.1 5.0 | 4.7 40.5 280 22 12 9.7 5.3
13500 5.0 41.0 265 22 11 9.2 5.0 | 6.2 43.2 280 22 11 9.6 5.3
13000 6.3 43.3 265 21 11 9.4 5.2 | 7.6 45.7 280 22 11 9.4 5.2
12500 7.7 45.9 265 21 11 9.4 5.2 | 9.0 48.2 275 21 11 9.4 5.2
12000 9.1 48.4 265 21 11 9.5 5.2 | 10.4 50.7 275 21 11 9.4 5.2
11500 10.5 50.9 265 21 11 9.5 5.2 | 11.8 53.2 275 21 11 9.5 5.2
11000 11.9 53.4 265 20 10 8.7 4.8 | 13.1 55.6 270 21 11 7.9 4.3
10500 13.2 55.8 265 20 10 10.8 5.9 | 14.2 57.6 270 21 11 12.2 6.7
10250 14.1 57.4 265 20 10 11.3 6.2 | 15.4 59.7 270 21 11 13.4 7.3
10000 14.8 58.6 265 19 10 8.9 4.9 | 16.1 61.0 270 20 10 8.4 4.6
9750 15.5 59.9 265 19 10 9.6 5.3 | 16.8 62.2 270 20 10 9.8 5.4
9500 16.2 61.2 265 18 10 9.4 5.2 | 17.5 63.5 270 20 10 9.2 5.1
9250 16.9 62.4 265 18 9 9.6 5.3 | 18.1 64.6 265 20 10 7.9 4.3
9000 17.6 63.7 265 18 9 9.8 5.4 | 18.7 65.7 265 19 10 9.2 5.0
8750 19.1 66.4 265 18 9 9.8 5.4 | 19.5 67.1 265 19 10 11.0 6.0
8500 19.8 67.6 265 18 9 8.2 4.5 | 21.0 69.8 265 19 10 8.9 4.9
8250 20.4 68.7 265 18 9 9.5 5.2 | 21.7 71.1 260 19 10 9.2 5.1
8000 21.2 70.2 265 17 9 12.1 6.7 | 22.5 72.5 265 18 10 11.0 6.1
7750 22.1 71.8 265 17 9 10.6 5.8 | 23.2 73.8 265 18 9 10.1 5.5
7500 22.8 73.0 265 17 9 8.1 4.4 | 23.9 75.0 265 18 9 8.1 4.5
7250 23.4 74.1 265 17 9 8.5 4.7 | 24.5 76.1 260 18 9 8.3 4.6
7000 24.1 75.4 265 17 9 12.3 6.7 | 25.3 77.5 260 18 9 11.5 6.3
6750 25.1 77.2 265 16 8 12.0 6.6 | 26.2 79.2 260 17 9 11.5 6.3
6500 25.9 78.6 265 16 8 10.3 5.7 | 27.0 80.6 260 17 9 10.0 5.5
6250 26.7 80.1 265 16 8 9.9 5.5 | 27.7 81.9 260 17 9 10.0 5.5
6000 27.4 81.3 265 15 8 11.8 6.4 | 28.4 83.1 260 16 8 9.4 5.1
5750 28.7 83.7 265 14 7 24.0 13.2 | 29.2 84.6 260 14 7 14.0 7.7
5500 31.3 88.3 265 13 7 48.8 26.8 | 31.1 88.0 255 13 7 43.2 23.7
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.
042613