Soaring Guidance Issued by NWS Pueblo, CO
000
UXUS97 KPUB 121207
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0607 MDT Tuesday, March 12, 2024
This forecast is for the Air Force Academy for Tuesday, March 12, 2024:
If the trigger temperature of 42.9 F/6.0 C is reached...then
Thermal Soaring Index....................... Excellent
Maximum rate of lift........................ 1398 ft/min (7.1 m/s)
Maximum height of thermals.................. 22704 ft MSL (15068 ft AGL)
Forecast maximum temperature................... 61.0 F/16.6 C
Time of trigger temperature.................... 0900 MDT
Time of overdevelopment........................ 1200 MDT
Middle/high clouds during soaring window....... None
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 20606 ft MSL (12970 ft AGL)
Thermal soaring outlook for Wednesday 03/13.... Fair
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 07:13:53 / 19:03:41 MDT
Total possible sunshine........... 11 hr 49 min 48 sec (709 min 48 sec)
Altitude of sun at 13:08:47 MDT... 48.07 degrees
Upper air data from numerical model forecast valid on 03/12/2024 at 0600 MDT
Freezing level.................. 9277 ft MSL (1641 ft AGL)
Convective condensation level... 14728 ft MSL (7092 ft AGL)
Lifted condensation level....... 18108 ft MSL (10472 ft AGL)
Lifted index.................... -1.5
K index......................... +4.5
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 -57.1 -70.8 260 26 13 2.0 1.1 M M M M M
45000 -54.0 -65.2 270 35 18 2.3 1.3 M M M M M
40000 -56.8 -70.2 285 38 19 -2.2 -1.2 M M M M M
38000 -57.4 -71.3 295 39 20 2.0 1.1 M M M M M
36000 -56.1 -69.0 310 43 22 2.1 1.2 M M M M M
34000 -54.5 -66.1 325 51 26 5.7 3.1 M M M M M
32000 -50.5 -58.9 335 53 28 6.7 3.7 M M M M M
30000 -46.4 -51.5 340 57 29 8.0 4.4 22.4 72.3 4.8 M M
29000 -44.0 -47.2 340 58 30 8.1 4.5 21.6 70.9 4.3 M M
28000 -41.6 -42.9 340 58 30 8.1 4.5 21.0 69.7 3.8 M M
27000 -39.1 -38.4 335 59 30 8.2 4.5 20.5 68.8 3.5 M M
26000 -36.8 -34.2 335 56 29 7.7 4.2 19.7 67.5 2.9 M M
25000 -34.5 -30.1 330 52 27 7.7 4.2 18.9 66.0 2.3 M M
24000 -32.2 -26.0 320 49 25 7.7 4.2 18.2 64.7 1.7 M M
23000 -30.4 -22.7 320 43 22 4.9 2.7 16.9 62.3 0.6 M M
22000 -28.6 -19.5 315 34 17 4.9 2.7 14.7 58.4 -1.2 1337 6.8
21000 -27.1 -16.8 310 27 14 5.5 3.0 13.1 55.5 -2.6 1264 6.4
20000 -25.3 -13.5 305 23 12 6.2 3.4 11.7 53.1 -3.8 1179 6.0
19500 -24.4 -11.9 300 22 11 6.2 3.4 11.1 52.0 -4.4 1137 5.8
19000 -23.4 -10.1 295 20 10 6.3 3.5 10.6 51.0 -4.9 1094 5.6
18500 -22.5 -8.5 295 19 10 7.0 3.9 10.0 50.0 -5.5 1052 5.3
18000 -21.3 -6.3 290 19 10 8.3 4.6 9.7 49.5 -5.8 1001 5.1
17500 -20.1 -4.2 290 19 10 8.4 4.6 9.5 49.1 -6.0 950 4.8
17000 -18.9 -2.0 290 20 10 8.1 4.4 9.2 48.6 -6.3 899 4.6
16500 -17.7 0.1 290 20 11 8.1 4.5 9.0 48.1 -6.6 848 4.3
16000 -16.5 2.3 290 21 11 8.0 4.4 8.7 47.6 -6.9 798 4.1
15500 -15.3 4.5 290 22 12 7.9 4.4 8.4 47.1 -7.3 748 3.8
15000 -14.2 6.4 290 24 12 7.9 4.4 8.1 46.6 -7.6 698 3.5
14500 -13.0 8.6 290 25 13 7.9 4.4 7.8 46.0 -7.9 648 3.3
14000 -11.8 10.8 295 26 13 8.0 4.4 7.5 45.5 -8.2 598 3.0
13500 -10.6 12.9 295 27 14 8.5 4.7 7.3 45.1 -8.5 546 2.8
13000 -9.3 15.3 295 29 15 9.1 5.0 7.1 44.7 -8.8 494 2.5
12500 -7.9 17.8 295 30 15 7.9 4.4 7.0 44.7 -8.9 437 2.2
12000 -6.9 19.6 295 33 17 6.9 3.8 6.6 43.8 -9.4 392 2.0
11750 -6.4 20.5 295 34 17 8.5 4.6 6.4 43.5 -9.6 369 1.9
11500 -5.7 21.7 295 34 18 9.0 4.9 6.3 43.4 -9.7 341 1.7
11250 -5.1 22.8 295 35 18 7.8 4.3 6.2 43.2 -9.8 316 1.6
11000 -4.5 23.9 295 35 18 7.8 4.3 6.1 42.9 -10.0 292 1.5
10750 -4.0 24.8 295 34 17 8.1 4.4 5.9 42.7 -10.2 267 1.4
10500 -3.4 25.9 300 31 16 8.0 4.4 5.8 42.4 -10.4 242 1.2
10250 -2.7 27.1 300 29 15 8.9 4.9 5.7 42.2 -10.5 216 1.1
10000 -2.0 28.4 300 27 14 9.5 5.2 5.7 42.2 -10.6 188 1.0
9750 -1.4 29.5 300 26 13 8.4 4.6 5.6 42.1 -10.7 160 0.8
9500 -0.8 30.6 300 25 13 8.0 4.4 5.5 41.8 -10.8 135 0.7
9250 -0.2 31.6 300 24 12 8.4 4.6 5.4 41.6 -11.0 110 0.6
9000 0.4 32.7 300 23 12 7.1 3.9 5.2 41.4 -11.1 85 0.4
8750 0.8 33.4 300 22 11 5.7 3.1 4.9 40.9 -11.5 64 0.3
8500 1.2 34.2 300 21 11 4.3 2.4 4.6 40.3 -11.9 46 0.2
8250 2.2 36.0 300 19 10 0.1 0.0 4.1 39.5 -12.4 2 0.0
8000 1.1 34.0 295 13 6 -27.7 -15.2 2.3 36.2 -14.3 27 0.1
7750 0.0 32.0 280 7 4 25.5 14.0 0.5 33.0 -16.1 52 0.3
7500 M M M M M M M M M M M M
7250 M M M M M M M M M M M M
7000 M M M M M M M M M M M M
6750 M M M M M M M M M M M M
* * * * * * Numerical weather prediction model forecast data valid * * * * * *
03/12/2024 at 0900 MDT | 03/12/2024 at 1200 MDT
|
CAPE... 0.0 LI... +5.2 | CAPE... 0.0 LI... +4.7
CINH... 0.0 K Index... -18.2 | CINH... 0.0 K Index... -14.9
|
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 -57.2 -71.0 260 29 15 2.1 1.2 | -57.5 -71.5 265 29 15 0.9 0.5
45000 -54.0 -65.2 265 34 18 2.7 1.5 | -56.2 -69.2 265 33 17 1.2 0.6
40000 -60.5 -76.9 285 54 28 -4.8 -2.6 | -59.7 -75.5 270 49 25 -2.5 -1.4
38000 -61.8 -79.2 290 58 30 3.6 2.0 | -60.2 -76.4 275 53 27 2.2 1.2
36000 -59.3 -74.7 300 50 26 3.7 2.1 | -58.7 -73.7 275 51 26 2.3 1.2
34000 -56.7 -70.1 310 44 23 9.3 5.1 | -56.9 -70.4 270 50 26 9.7 5.3
32000 -51.3 -60.3 310 42 22 9.0 5.0 | -51.6 -60.9 275 48 25 8.8 4.8
30000 -46.0 -50.8 310 41 21 8.2 4.5 | -46.3 -51.3 275 46 24 8.7 4.8
29000 -43.5 -46.3 310 42 21 8.3 4.5 | -43.7 -46.7 280 44 23 8.8 4.8
28000 -41.0 -41.8 310 43 22 8.3 4.5 | -41.0 -41.8 280 43 22 8.8 4.8
27000 -38.5 -37.3 310 44 22 8.3 4.5 | -38.4 -37.1 285 41 21 8.7 4.8
26000 -36.1 -33.0 310 44 22 8.1 4.4 | -35.9 -32.6 285 38 19 8.4 4.6
25000 -33.7 -28.7 310 43 22 8.1 4.4 | -33.4 -28.1 280 34 18 8.4 4.6
24000 -31.3 -24.3 310 43 22 8.1 4.4 | -30.8 -23.4 280 31 16 8.5 4.7
23000 -28.9 -20.0 310 42 22 8.1 4.4 | -28.4 -19.1 280 30 16 7.9 4.3
22000 -26.4 -15.5 305 41 21 8.1 4.4 | -25.5 -13.9 280 30 16 7.9 4.4
21000 -23.4 -10.1 305 39 20 7.6 4.2 | -23.1 -9.6 275 31 16 8.0 4.4
20000 -21.2 -6.2 305 37 19 7.5 4.1 | -20.7 -5.3 275 30 16 8.0 4.4
19500 -20.0 -4.0 305 36 19 7.5 4.1 | -19.5 -3.1 275 30 16 8.0 4.4
19000 -18.9 -2.0 305 36 18 7.4 4.1 | -18.3 -0.9 275 30 15 8.0 4.4
18500 -17.8 -0.0 310 35 18 6.1 3.3 | -17.1 1.2 275 30 15 8.2 4.5
18000 -17.1 1.2 305 32 16 4.9 2.7 | -15.8 3.6 270 29 15 8.4 4.6
17500 -16.4 2.5 305 29 15 4.8 2.6 | -14.6 5.7 265 28 14 8.3 4.6
17000 -15.7 3.7 300 25 13 4.6 2.5 | -13.5 7.7 265 27 14 6.6 3.6
16500 -15.0 5.0 295 22 11 4.5 2.5 | -12.4 9.7 270 25 13 6.9 3.8
16000 -14.2 6.4 295 19 10 6.0 3.3 | -11.5 11.3 270 23 12 4.7 2.6
15500 -13.3 8.1 295 17 9 6.3 3.5 | -10.9 12.4 270 22 11 4.3 2.4
15000 -12.4 9.7 300 16 8 6.7 3.7 | -10.3 13.5 275 20 10 3.3 1.8
14500 -11.3 11.7 305 16 8 7.0 3.8 | -9.9 14.2 275 18 9 2.5 1.3
14000 -10.3 13.5 310 16 8 7.1 3.9 | -9.6 14.7 275 17 9 3.2 1.7
13500 -9.3 15.3 310 18 10 7.3 4.0 | -8.9 16.0 280 14 7 5.6 3.1
13000 -8.2 17.2 315 21 11 7.7 4.2 | -8.1 17.4 290 12 6 7.1 3.9
12500 -7.2 19.0 310 22 11 5.0 2.7 | -6.8 19.8 300 11 6 7.6 4.2
12000 -6.6 20.1 305 24 12 4.4 2.4 | -5.9 21.4 315 12 6 6.7 3.7
11750 -6.2 20.8 305 25 13 6.5 3.6 | -5.4 22.3 315 12 6 7.4 4.0
11500 -5.7 21.7 305 24 12 7.6 4.1 | -4.8 23.4 315 12 6 7.5 4.1
11250 -5.1 22.8 300 23 12 6.9 3.8 | -4.3 24.3 310 11 6 6.9 3.8
11000 -4.6 23.7 300 23 12 6.9 3.8 | -3.8 25.2 305 10 5 7.2 3.9
10750 -4.1 24.6 300 23 12 6.5 3.6 | -3.3 26.1 300 9 5 8.0 4.4
10500 -3.7 25.3 300 25 13 6.3 3.5 | -2.7 27.1 295 8 4 8.2 4.5
10250 -3.2 26.2 300 27 14 6.6 3.6 | -2.1 28.2 285 7 3 9.5 5.2
10000 -2.7 27.1 300 27 14 7.0 3.8 | -1.4 29.5 285 6 3 10.6 5.8
9750 -2.2 28.0 300 26 13 7.1 3.9 | -0.6 30.9 285 6 3 9.9 5.4
9500 -1.7 28.9 295 25 13 7.0 3.8 | 0.1 32.2 285 6 3 9.8 5.4
9250 -1.2 29.8 295 23 12 7.6 4.1 | 0.9 33.6 285 6 3 9.9 5.4
9000 -0.6 30.9 295 22 11 8.5 4.6 | 1.6 34.9 285 6 3 10.3 5.7
8750 0.0 32.0 295 20 10 8.5 4.7 | 2.4 36.3 285 5 3 10.4 5.7
8500 0.6 33.1 290 19 10 8.3 4.6 | 3.2 37.8 285 5 3 11.0 6.0
8250 1.2 34.2 290 18 9 8.6 4.7 | 4.0 39.2 290 5 3 8.9 4.9
8000 1.9 35.4 285 16 8 10.6 5.8 | 4.7 40.5 290 5 2 13.9 7.6
7750 2.8 37.0 285 11 6 13.2 7.2 | 7.8 46.0 290 4 2 1.0 0.5
7500 M M M M M M M | M M M M M M M
7250 M M M M M M M | M M M M M M M
7000 M M M M M M M | M M M M M M M
6750 M M M M M M M | M M M M M M M
03/12/2024 at 1500 MDT | 03/12/2024 at 1800 MDT
|
CAPE... +0.2 LI... +1.5 | CAPE... +0.3 LI... +1.0
CINH... -0.2 K Index... +4.1 | CINH... -2.2 K Index... +17.5
|
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 -57.2 -71.0 260 30 15 0.7 0.4 | -56.9 -70.4 265 34 18 0.5 0.3
45000 -56.2 -69.2 270 43 22 1.0 0.6 | -56.1 -69.0 270 39 20 0.8 0.5
40000 -59.4 -74.9 270 54 28 -2.3 -1.3 | -59.8 -75.6 265 57 29 -2.7 -1.5
38000 -59.8 -75.6 265 56 29 2.4 1.3 | -60.4 -76.7 265 62 32 2.7 1.5
36000 -58.2 -72.8 265 54 28 2.4 1.3 | -58.5 -73.3 265 63 33 2.8 1.5
34000 -56.3 -69.3 265 53 27 9.4 5.2 | -56.4 -69.5 265 62 32 9.8 5.4
32000 -51.1 -60.0 260 49 25 8.7 4.7 | -51.0 -59.8 260 49 25 9.0 4.9
30000 -45.8 -50.4 260 46 24 9.5 5.2 | -45.6 -50.1 255 38 20 9.2 5.0
29000 -43.0 -45.4 265 45 23 9.5 5.2 | -42.9 -45.2 255 37 19 9.2 5.0
28000 -40.1 -40.2 265 44 22 9.5 5.2 | -40.1 -40.2 255 35 18 9.2 5.0
27000 -37.3 -35.1 270 42 22 9.3 5.1 | -37.4 -35.3 250 34 18 9.1 5.0
26000 -34.9 -30.8 270 43 22 8.0 4.4 | -35.0 -31.0 255 36 18 7.7 4.2
25000 -32.5 -26.5 265 43 22 8.0 4.4 | -32.7 -26.9 255 38 19 7.7 4.2
24000 -30.1 -22.2 265 44 23 8.1 4.5 | -30.4 -22.7 255 40 20 7.9 4.3
23000 -27.9 -18.2 265 42 22 7.0 3.8 | -28.3 -18.9 260 40 21 6.8 3.7
22000 -25.4 -13.7 260 39 20 7.0 3.8 | -26.3 -15.3 260 41 21 6.8 3.7
21000 -23.3 -9.9 260 37 19 7.0 3.8 | -23.7 -10.7 265 41 21 7.4 4.1
20000 -21.2 -6.2 260 34 18 7.0 3.8 | -21.5 -6.7 265 37 19 7.6 4.1
19500 -20.1 -4.2 255 33 17 7.0 3.8 | -20.4 -4.7 265 36 18 7.6 4.2
19000 -19.1 -2.4 255 32 16 7.0 3.8 | -19.2 -2.6 270 34 17 7.6 4.1
18500 -18.0 -0.4 255 30 16 8.2 4.5 | -18.1 -0.6 270 32 16 7.1 3.9
18000 -16.6 2.1 255 30 16 9.0 5.0 | -17.1 1.2 270 31 16 6.8 3.7
17500 -15.2 4.6 255 30 16 9.0 5.0 | -16.1 3.0 270 29 15 6.8 3.7
17000 -14.1 6.6 255 30 15 6.6 3.6 | -15.2 4.6 270 29 15 5.8 3.2
16500 -13.0 8.6 260 30 15 6.8 3.8 | -14.3 6.3 270 29 15 5.8 3.2
16000 -12.1 10.2 260 29 15 6.1 3.4 | -13.4 7.9 265 28 15 6.8 3.7
15500 -11.2 11.8 265 30 15 6.0 3.3 | -12.4 9.7 265 28 14 7.0 3.8
15000 -10.3 13.5 265 30 15 5.4 3.0 | -11.3 11.7 260 27 14 7.4 4.1
14500 -9.6 14.7 265 28 14 4.9 2.7 | -10.2 13.6 255 24 12 7.9 4.3
14000 -8.9 16.0 260 26 13 5.3 2.9 | -9.0 15.8 250 20 10 8.2 4.5
13500 -8.1 17.4 255 20 10 6.3 3.5 | -7.7 18.1 245 18 9 9.3 5.1
13000 -7.3 18.9 250 14 7 8.1 4.4 | -6.4 20.5 245 16 8 11.9 6.5
12500 -6.0 21.2 240 11 6 8.2 4.5 | -4.8 23.4 240 15 8 7.6 4.2
12000 -4.8 23.4 230 8 4 7.9 4.3 | -3.6 25.5 235 14 7 7.8 4.3
11750 -4.2 24.4 225 8 4 9.1 5.0 | -3.0 26.6 235 13 7 9.3 5.1
11500 -3.5 25.7 220 7 4 9.6 5.3 | -2.3 27.9 230 13 7 9.4 5.1
11250 -2.8 27.0 215 7 4 9.3 5.1 | -1.6 29.1 225 13 7 8.2 4.5
11000 -2.1 28.2 210 7 3 9.3 5.1 | -1.0 30.2 225 13 6 8.5 4.7
10750 -1.4 29.5 205 7 3 9.1 5.0 | -0.4 31.3 220 12 6 8.2 4.5
10500 -0.7 30.7 200 7 3 8.9 4.9 | 0.2 32.4 215 12 6 8.1 4.4
10250 -0.0 32.0 200 7 3 10.2 5.6 | 0.9 33.6 210 12 6 9.6 5.3
10000 0.8 33.4 195 6 3 10.9 6.0 | 1.6 34.9 205 12 6 10.4 5.7
9750 1.6 34.9 195 6 3 9.9 5.5 | 2.4 36.3 200 12 6 8.9 4.9
9500 2.3 36.1 190 6 3 9.6 5.2 | 3.0 37.4 195 12 6 8.0 4.4
9250 3.0 37.4 190 6 3 9.9 5.4 | 3.6 38.5 190 12 6 8.6 4.7
9000 3.8 38.8 185 6 3 10.3 5.7 | 4.2 39.6 185 12 6 9.4 5.1
8750 4.5 40.1 185 6 3 10.2 5.6 | 5.0 41.0 180 11 6 9.8 5.4
8500 5.3 41.5 180 6 3 10.8 5.9 | 5.7 42.3 180 11 6 10.0 5.5
8250 6.1 43.0 180 6 3 8.6 4.7 | 6.4 43.5 175 11 6 9.5 5.2
8000 6.7 44.1 180 6 3 11.5 6.3 | 7.1 44.8 170 11 6 9.4 5.2
7750 8.0 46.4 175 6 3 23.0 12.6 | 7.8 46.0 170 10 5 10.8 5.9
7500 M M M M M M M | M M M M M M M
7250 M M M M M M M | M M M M M M M
7000 M M M M M M M | M M M M M M M
6750 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). 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 Air Force Academy
in Colorado Springs, Colorado at
North Latitude: 38 deg 58 min 48.000 sec
West Longitude: 104 deg 49 min 12.000 sec
Elevation: 6572 feet (2003 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.
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