Soaring Guidance
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
322
UXUS97 KGJT 161307
SRGGJT
Soaring Forecast
National Weather Service Grand Junction, Colorado
707 AM MDT Sunday, June 16, 2024
This forecast is for Sunday, June 16, 2024:
If the trigger temperature of 87.1 F/30.6 C is reached...then
Thermal Soaring Index....................... Excellent
Maximum rate of lift........................ 1496 ft/min (7.6 m/s)
Maximum height of thermals.................. 20409 ft MSL (15570 ft AGL)
Forecast maximum temperature................... 97.0 F/36.6 C
Time of trigger temperature.................... 1045 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................. 15987 ft MSL (11148 ft AGL)
Thermal soaring outlook for Monday 06/17....... Excellent
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 05:47:41 / 20:42:23 MDT
Total possible sunshine........... 14 hr 54 min 42 sec (894 min 42 sec)
Altitude of sun at 13:15:02 MDT... 73.94 degrees
Upper air data from rawinsonde observation taken on 06/16/2024 at 0600 MDT
Freezing level.................. 15731 ft MSL (10892 ft AGL)
Convective condensation level... 22814 ft MSL (17975 ft AGL)
Lifted condensation level....... 22067 ft MSL (17227 ft AGL)
Lifted index.................... +1.5
K index......................... -2.2
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 -60.9 -77.6 270 54 28 -0.5 -0.3 93.7 200.6 33.3 M M
45000 -61.6 -78.9 280 60 31 -6.4 -3.5 66.8 152.2 19.1 M M
40000 -54.6 -66.3 270 64 33 7.6 4.2 54.9 130.7 12.5 M M
38000 -50.0 -58.0 275 60 31 7.2 4.0 53.0 127.5 11.6 M M
36000 -45.7 -50.3 270 56 29 8.1 4.4 50.8 123.4 10.3 M M
34000 -40.8 -41.4 270 54 28 7.8 4.3 49.5 121.1 9.6 M M
32000 -36.0 -32.8 265 57 29 7.6 4.2 48.1 118.6 8.9 M M
30000 -31.0 -23.8 260 55 28 6.9 3.8 46.1 115.0 7.5 M M
29000 -28.9 -20.0 260 51 26 8.7 4.8 45.0 113.0 6.8 M M
28000 -26.0 -14.8 255 53 27 9.6 5.3 45.0 112.9 6.8 M M
27000 -23.8 -10.8 260 47 24 6.0 3.3 44.1 111.4 6.2 M M
26000 -22.1 -7.8 265 42 22 5.9 3.2 42.6 108.8 5.1 M M
25000 -20.1 -4.2 255 43 22 6.7 3.7 41.4 106.4 4.1 M M
24000 -18.1 -0.6 260 41 21 6.9 3.8 40.3 104.5 3.3 M M
23000 -16.0 3.2 265 41 21 7.2 3.9 39.3 102.7 2.5 M M
22000 -13.8 7.2 265 40 21 7.4 4.0 38.4 101.2 1.9 M M
21000 -11.5 11.3 250 37 19 7.6 4.2 37.6 99.6 1.2 M M
20000 -10.8 12.6 230 35 18 3.2 1.8 35.2 95.3 -1.0 1484 7.5
19500 -10.4 13.3 230 34 17 3.3 1.8 34.0 93.2 -2.1 1459 7.4
19000 -9.5 14.9 225 34 17 9.3 5.1 33.4 92.2 -2.6 1416 7.2
18500 -8.1 17.4 225 33 17 9.2 5.1 33.4 92.1 -2.7 1360 6.9
18000 -6.7 19.9 225 31 16 9.2 5.1 33.3 92.0 -2.7 1304 6.6
17500 -5.3 22.5 225 30 15 9.2 5.1 33.3 91.9 -2.8 1247 6.3
17000 -3.9 25.0 230 29 15 9.2 5.1 33.2 91.8 -2.8 1191 6.0
16500 -1.8 28.8 235 28 14 9.2 5.1 33.1 91.6 -2.9 1106 5.6
16000 -0.5 31.1 240 30 15 9.2 5.1 33.0 91.4 -3.0 1050 5.3
15500 0.9 33.6 240 30 16 9.2 5.1 32.9 91.3 -3.1 993 5.0
15000 2.3 36.1 245 30 15 9.2 5.1 32.8 91.1 -3.2 937 4.8
14500 3.7 38.7 250 28 14 9.2 5.1 32.7 90.9 -3.3 881 4.5
14000 5.1 41.2 240 30 15 9.2 5.1 32.6 90.7 -3.4 824 4.2
13500 6.5 43.7 245 29 15 9.2 5.1 32.5 90.5 -3.6 768 3.9
13000 7.9 46.2 245 29 15 9.3 5.1 32.3 90.2 -3.7 712 3.6
12500 9.2 48.6 250 28 14 8.7 4.8 32.2 90.0 -3.8 656 3.3
12000 10.5 50.9 255 27 14 8.6 4.7 32.0 89.6 -4.1 604 3.1
11500 11.8 53.2 260 24 12 8.7 4.8 31.9 89.3 -4.3 551 2.8
11000 13.1 55.6 260 23 12 8.5 4.6 31.7 89.0 -4.4 497 2.5
10500 14.2 57.6 255 23 12 7.6 4.2 31.3 88.4 -4.8 449 2.3
10250 14.8 58.6 255 24 12 9.3 5.1 31.2 88.2 -4.9 423 2.1
10000 15.5 59.9 255 24 12 9.1 5.0 31.2 88.1 -5.0 395 2.0
9750 16.2 61.2 255 24 13 8.9 4.9 31.1 88.0 -5.1 367 1.9
9500 16.8 62.2 250 25 13 9.0 4.9 31.1 87.9 -5.1 340 1.7
9250 17.5 63.5 250 25 13 9.0 4.9 31.0 87.9 -5.2 312 1.6
9000 18.2 64.8 250 25 13 9.0 4.9 31.0 87.8 -5.3 285 1.4
8750 18.8 65.8 250 25 13 9.0 4.9 30.9 87.7 -5.3 257 1.3
8500 19.5 67.1 250 25 13 9.0 4.9 30.9 87.5 -5.4 230 1.2
8250 20.2 68.4 250 26 13 9.0 4.9 30.8 87.4 -5.5 203 1.0
8000 20.8 69.4 250 26 13 9.0 4.9 30.7 87.3 -5.5 175 0.9
7750 21.5 70.7 250 25 13 8.8 4.8 30.7 87.2 -5.6 148 0.8
7500 22.1 71.8 250 24 12 6.0 3.3 30.5 86.9 -5.8 123 0.6
7250 22.4 72.3 250 19 10 3.5 1.9 30.1 86.2 -6.3 107 0.5
7000 22.7 72.9 245 14 7 6.0 3.3 29.7 85.5 -6.7 91 0.5
6750 23.0 73.4 240 12 6 -1.1 -0.6 29.3 84.7 -7.2 75 0.4
6500 22.5 72.5 220 8 4 -2.6 -1.4 28.2 82.7 -8.3 81 0.4
6250 22.7 72.9 190 7 4 5.2 2.9 27.7 81.8 -8.9 69 0.4
6000 23.0 73.4 165 9 5 4.4 2.4 27.3 81.1 -9.4 52 0.3
5750 23.3 73.9 165 11 5 6.8 3.7 26.9 80.5 -9.8 35 0.2
5500 23.5 74.3 155 12 6 -5.2 -2.8 26.5 79.7 -10.3 20 0.1
5250 22.6 72.7 150 11 6 -11.5 -6.3 24.8 76.7 -12.0 42 0.2
5000 22.4 72.3 130 7 4 8.3 4.6 24.0 75.1 -13.0 40 0.2
* * * * * * Numerical weather prediction model forecast data valid * * * * * *
06/16/2024 at 0900 MDT | 06/16/2024 at 1200 MDT
|
CAPE... 0.0 LI... +3.5 | CAPE... 0.0 LI... +3.5
CINH... -0.8 K Index... +4.6 | CINH... -0.6 K Index... +7.1
|
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 -61.3 -78.3 265 45 23 0.6 0.3 | -61.7 -79.1 260 47 24 0.9 0.5
45000 -59.5 -75.1 270 54 28 2.9 1.6 | -59.3 -74.7 265 54 28 3.2 1.8
40000 -54.6 -66.3 265 56 29 7.8 4.3 | -54.1 -65.4 255 52 27 7.3 4.0
38000 -50.0 -58.0 265 56 29 7.5 4.1 | -49.8 -57.6 255 53 27 7.2 3.9
36000 -45.5 -49.9 260 57 29 7.5 4.1 | -45.5 -49.9 255 53 27 7.2 3.9
34000 -40.8 -41.4 260 58 30 7.9 4.3 | -40.7 -41.3 250 54 28 8.2 4.5
32000 -36.1 -33.0 260 59 30 7.9 4.3 | -35.7 -32.3 250 54 28 8.2 4.5
30000 -31.2 -24.2 260 58 30 8.2 4.5 | -30.8 -23.4 250 54 28 8.2 4.5
29000 -28.8 -19.8 260 56 29 8.2 4.5 | -28.4 -19.1 250 53 27 8.2 4.5
28000 -26.3 -15.3 260 55 28 8.4 4.6 | -25.9 -14.6 250 53 27 8.3 4.6
27000 -23.7 -10.7 255 51 26 6.5 3.6 | -23.2 -9.8 250 50 26 7.1 3.9
26000 -21.8 -7.2 255 48 25 6.6 3.6 | -21.1 -6.0 250 48 25 7.1 3.9
25000 -19.8 -3.6 250 45 23 6.6 3.6 | -18.9 -2.0 250 46 24 7.2 4.0
24000 -17.9 -0.2 250 42 22 6.6 3.6 | -17.0 1.4 245 44 22 6.4 3.5
23000 -15.9 3.4 250 40 21 6.6 3.6 | -15.0 5.0 245 41 21 6.4 3.5
22000 -13.9 7.0 250 38 19 6.6 3.6 | -13.1 8.4 245 39 20 6.4 3.5
21000 -11.9 10.6 245 37 19 6.7 3.7 | -11.2 11.8 245 37 19 6.4 3.5
20000 -9.9 14.2 240 36 19 6.7 3.7 | -9.3 15.3 245 36 18 6.4 3.5
19500 -8.9 16.0 240 36 19 6.7 3.7 | -8.3 17.1 240 35 18 6.4 3.5
19000 -7.9 17.8 235 36 18 6.7 3.7 | -7.4 18.7 240 35 18 5.4 3.0
18500 -6.9 19.6 235 36 18 6.7 3.7 | -6.7 19.9 240 34 18 5.0 2.8
18000 -5.9 21.4 235 36 18 6.8 3.7 | -6.0 21.2 235 34 17 5.0 2.8
17500 -4.8 23.4 230 36 18 7.9 4.3 | -5.1 22.8 235 33 17 6.2 3.4
17000 -3.7 25.3 230 35 18 7.8 4.3 | -4.3 24.3 230 33 17 6.1 3.3
16500 -2.5 27.5 225 35 18 8.1 4.5 | -3.3 26.1 230 32 16 7.8 4.3
16000 -1.3 29.7 225 34 17 8.2 4.5 | -2.1 28.2 230 31 16 8.3 4.6
15500 -0.1 31.8 225 33 17 8.4 4.6 | -0.9 30.4 225 30 15 8.6 4.7
15000 1.2 34.2 225 31 16 8.8 4.8 | 0.5 32.9 225 29 15 9.2 5.1
14500 2.5 36.5 230 28 15 8.8 4.8 | 1.8 35.2 225 28 14 9.2 5.1
14000 3.8 38.8 230 26 14 8.4 4.6 | 3.2 37.8 225 27 14 9.0 5.0
13500 5.1 41.2 230 24 13 8.4 4.6 | 4.5 40.1 225 26 13 9.0 5.0
13000 6.3 43.3 230 23 12 8.5 4.6 | 5.9 42.6 225 25 13 9.4 5.1
12500 7.6 45.7 235 21 11 8.5 4.7 | 7.3 45.1 220 24 12 9.4 5.2
12000 8.8 47.8 235 20 10 8.6 4.7 | 8.7 47.7 220 23 12 9.4 5.2
11500 10.1 50.2 235 19 10 8.6 4.7 | 10.1 50.2 220 23 12 9.5 5.2
11000 11.3 52.3 235 19 10 7.6 4.2 | 11.5 52.7 220 22 11 8.7 4.8
10500 12.4 54.3 235 18 9 7.2 3.9 | 12.8 55.0 225 21 11 8.8 4.8
10250 13.0 55.4 235 18 9 10.1 5.5 | 13.5 56.3 225 20 10 11.1 6.1
10000 13.8 56.8 235 18 9 9.2 5.1 | 14.4 57.9 225 20 11 10.6 5.8
9750 14.3 57.7 235 17 9 6.6 3.6 | 15.1 59.2 225 20 10 9.2 5.1
9500 15.4 59.7 235 17 9 8.1 4.5 | 15.8 60.4 225 19 10 9.5 5.2
9250 16.1 61.0 230 16 8 8.0 4.4 | 17.3 63.1 225 19 10 10.2 5.6
9000 16.6 61.9 225 15 8 6.5 3.5 | 18.0 64.4 225 18 9 9.8 5.4
8750 17.1 62.8 225 14 7 6.9 3.8 | 18.7 65.7 225 18 9 9.9 5.4
8500 17.6 63.7 220 13 7 6.5 3.6 | 19.5 67.1 225 18 9 9.8 5.4
8250 18.0 64.4 220 12 6 6.1 3.3 | 20.2 68.4 225 17 9 10.0 5.5
8000 18.5 65.3 215 11 6 6.0 3.3 | 21.0 69.8 225 17 9 10.1 5.6
7750 18.9 66.0 210 10 5 6.2 3.4 | 21.7 71.1 225 17 9 10.3 5.7
7500 19.4 66.9 205 10 5 5.6 3.1 | 22.5 72.5 225 16 8 9.4 5.2
7250 19.8 67.6 200 9 4 5.7 3.1 | 23.1 73.6 230 16 8 8.7 4.8
7000 20.2 68.4 195 8 4 8.0 4.4 | 23.9 75.0 230 16 8 10.3 5.6
6750 20.9 69.6 190 8 4 9.1 5.0 | 24.7 76.5 230 15 8 10.9 6.0
6500 21.5 70.7 185 8 4 9.2 5.1 | 25.5 77.9 225 15 8 10.9 6.0
6250 22.3 72.1 180 7 4 10.2 5.6 | 26.3 79.3 230 14 7 12.0 6.6
6000 23.0 73.4 175 6 3 8.1 4.5 | 27.2 81.0 230 14 7 8.4 4.6
5750 23.6 74.5 180 6 3 11.0 6.0 | 27.8 82.0 230 13 7 14.1 7.7
5500 25.5 77.9 170 5 3 52.0 28.5 | 31.0 87.8 230 12 6 92.4 50.7
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
06/16/2024 at 1500 MDT | 06/16/2024 at 1800 MDT
|
CAPE... 0.0 LI... +0.6 | CAPE... 0.0 LI... -0.1
CINH... -1.3 K Index... +10.3 | CINH... -0.6 K Index... +9.5
|
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 -61.1 -78.0 255 51 26 1.3 0.7 | -60.0 -76.0 260 55 28 1.6 0.9
45000 -58.5 -73.3 255 57 29 2.5 1.4 | -57.5 -71.5 260 63 33 2.0 1.1
40000 -54.3 -65.7 235 49 25 7.4 4.1 | -54.0 -65.2 240 48 25 6.6 3.6
38000 -49.9 -57.8 235 49 25 7.2 3.9 | -50.2 -58.4 230 49 25 6.2 3.4
36000 -45.6 -50.1 235 49 25 7.2 4.0 | -46.5 -51.7 220 51 26 6.3 3.4
34000 -40.9 -41.6 235 49 25 8.1 4.5 | -42.0 -43.6 220 49 25 7.8 4.3
32000 -36.0 -32.8 240 48 25 8.1 4.5 | -37.4 -35.3 225 46 23 7.8 4.3
30000 -31.3 -24.3 240 47 24 7.7 4.2 | -32.7 -26.9 230 43 22 7.8 4.3
29000 -29.0 -20.2 245 47 24 7.7 4.2 | -30.3 -22.5 235 42 22 7.8 4.3
28000 -26.7 -16.1 245 46 24 7.7 4.2 | -28.0 -18.4 235 41 21 7.8 4.3
27000 -23.9 -11.0 245 45 23 7.4 4.0 | -25.7 -14.3 240 41 21 7.8 4.3
26000 -21.7 -7.1 245 44 23 7.4 4.1 | -22.8 -9.0 240 40 21 7.8 4.3
25000 -19.5 -3.1 245 43 22 7.5 4.1 | -20.4 -4.7 240 40 20 7.9 4.4
24000 -17.4 0.7 245 41 21 6.8 3.7 | -18.5 -1.3 240 38 20 6.3 3.5
23000 -15.4 4.3 245 40 21 6.8 3.7 | -16.6 2.1 235 37 19 6.3 3.5
22000 -13.3 8.1 240 38 20 6.9 3.8 | -14.7 5.5 230 36 19 6.3 3.5
21000 -11.7 10.9 235 36 19 5.3 2.9 | -12.6 9.3 230 34 17 7.4 4.1
20000 -10.1 13.8 235 33 17 5.3 2.9 | -10.5 13.1 225 32 16 7.4 4.1
19500 -9.4 15.1 230 32 17 5.3 2.9 | -9.4 15.1 225 31 16 7.4 4.1
19000 -8.6 16.5 230 31 16 7.1 3.9 | -8.3 17.1 220 30 15 8.7 4.8
18500 -7.4 18.7 225 30 16 7.7 4.2 | -6.9 19.6 220 29 15 9.2 5.0
18000 -6.3 20.7 225 29 15 7.9 4.3 | -5.5 22.1 220 29 15 9.2 5.1
17500 -5.0 23.0 220 29 15 9.2 5.0 | -4.1 24.6 220 29 15 9.6 5.2
17000 -3.7 25.3 220 28 14 9.1 5.0 | -2.7 27.1 220 28 14 9.5 5.2
16500 -2.3 27.9 220 27 14 9.4 5.1 | -1.2 29.8 220 28 14 9.5 5.2
16000 -0.9 30.4 220 27 14 9.5 5.2 | 0.2 32.4 220 27 14 9.5 5.2
15500 0.5 32.9 220 27 14 9.5 5.2 | 1.6 34.9 220 27 14 9.5 5.2
15000 2.0 35.6 220 26 14 9.5 5.2 | 3.0 37.4 220 27 14 9.6 5.2
14500 3.4 38.1 220 26 13 9.5 5.2 | 4.5 40.1 220 26 14 9.6 5.2
14000 4.8 40.6 220 26 13 9.5 5.2 | 5.9 42.6 220 26 13 9.5 5.2
13500 6.2 43.2 220 25 13 9.5 5.2 | 7.3 45.1 220 26 13 9.6 5.2
13000 7.6 45.7 220 24 13 9.4 5.1 | 8.8 47.8 220 25 13 9.3 5.1
12500 9.0 48.2 220 24 12 9.3 5.1 | 10.2 50.4 220 25 13 9.3 5.1
12000 10.4 50.7 225 23 12 9.5 5.2 | 11.6 52.9 220 24 12 9.5 5.2
11500 11.9 53.4 225 23 12 9.5 5.2 | 13.0 55.4 220 24 12 9.6 5.3
11000 13.3 55.9 225 22 11 9.1 5.0 | 14.4 57.9 225 23 12 9.0 5.0
10500 14.6 58.3 230 21 11 9.4 5.2 | 15.7 60.3 225 22 11 9.3 5.1
10250 15.4 59.7 230 21 11 11.0 6.1 | 16.5 61.7 225 22 11 11.0 6.1
10000 16.2 61.2 230 22 11 10.6 5.8 | 17.3 63.1 225 22 11 10.4 5.7
9750 17.0 62.6 230 21 11 9.8 5.4 | 18.0 64.4 225 22 11 9.5 5.2
9500 17.7 63.9 230 21 11 10.1 5.6 | 18.7 65.7 230 21 11 9.7 5.3
9250 19.2 66.6 230 21 11 9.7 5.3 | 19.5 67.1 230 21 11 9.4 5.2
9000 19.9 67.8 230 21 11 10.2 5.6 | 20.9 69.6 230 21 11 10.0 5.5
8750 20.7 69.3 230 21 11 10.1 5.5 | 21.7 71.1 230 21 11 10.2 5.6
8500 21.4 70.5 230 21 11 10.2 5.6 | 22.4 72.3 230 20 10 9.2 5.1
8250 22.2 72.0 235 20 10 10.1 5.6 | 23.1 73.6 230 20 10 9.1 5.0
8000 23.0 73.4 230 20 10 10.0 5.5 | 23.8 74.8 230 20 10 10.0 5.5
7750 23.7 74.7 230 20 10 10.2 5.6 | 24.5 76.1 230 19 10 9.8 5.4
7500 24.5 76.1 230 19 10 9.4 5.2 | 25.3 77.5 230 19 10 9.6 5.3
7250 25.1 77.2 235 19 10 8.7 4.8 | 26.0 78.8 235 19 10 9.0 4.9
7000 25.8 78.4 235 19 10 10.2 5.6 | 26.7 80.1 235 19 10 9.6 5.3
6750 26.6 79.9 235 18 9 10.9 6.0 | 27.4 81.3 235 18 9 10.0 5.5
6500 27.4 81.3 235 18 9 10.9 6.0 | 28.2 82.8 235 17 9 10.4 5.7
6250 28.3 82.9 235 17 9 12.1 6.7 | 29.0 84.2 235 17 9 11.5 6.3
6000 29.2 84.6 235 17 9 8.6 4.7 | 29.9 85.8 235 17 9 14.0 7.7
5750 29.8 85.6 235 16 8 14.0 7.7 | 31.1 88.0 235 15 8 17.4 9.5
5500 33.0 91.4 240 14 7 92.8 50.9 | 32.3 90.1 240 14 7 11.7 6.4
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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