Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
582
UXUS97 KBOU 070116
SRGBOU
Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1913 MDT Sunday, October 6, 2024
This forecast is for Monday, October 7, 2024:
If the trigger temperature of 74.5 F/23.6 C is reached...then
Thermal Soaring Index....................... Excellent
Maximum rate of lift........................ 948 ft/min (4.8 m/s)
Maximum height of thermals.................. 15767 ft MSL (10468 ft AGL)
Forecast maximum temperature................... 81.0 F/27.7 C
Time of trigger temperature.................... 1130 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................. 10416 ft MSL (5117 ft AGL)
Thermal soaring outlook for Tuesday 10/08...... Good
Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1800 MDT)......... No change
Height of stable layer (12-18K ft MSL)......... None
Weak PVA/NVA (through 1800 MDT)................ Neither
Potential height of wave....................... 40942 ft MSL (35643 ft AGL)
Wave soaring outlook for Tuesday 10/08......... Poor
Remarks...
Sunrise/Sunset.................... 07:02:29 / 18:31:41 MDT
Total possible sunshine........... 11 hr 29 min 12 sec (689 min 12 sec)
Altitude of sun at 12:47:05 MDT... 44.22 degrees
Upper air data from numerical model forecast valid on 10/07/2024 at 0600 MDT
Freezing level.................. 13991 ft MSL (8692 ft AGL)
Convective condensation level... 19041 ft MSL (13742 ft AGL)
Lifted condensation level....... 17972 ft MSL (12674 ft AGL)
Lifted index.................... +2.5
K index......................... +11.4
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 -64.5 -84.1 280 26 13 3.0 1.6 M M M M M
45000 -58.6 -73.5 270 33 17 6.7 3.7 M M M M M
40000 -48.4 -55.1 260 38 19 3.9 2.2 M M M M M
38000 -46.0 -50.8 260 38 19 4.0 2.2 M M M M M
36000 -43.6 -46.5 255 37 19 4.0 2.2 M M M M M
34000 -40.9 -41.6 255 36 19 4.7 2.6 M M M M M
32000 -38.1 -36.6 255 35 18 4.7 2.6 M M M M M
30000 -33.7 -28.7 255 35 18 7.4 4.0 42.0 107.7 11.3 M M
29000 -31.5 -24.7 255 36 18 7.4 4.0 41.1 106.1 10.7 M M
28000 -29.3 -20.7 255 36 19 7.2 3.9 40.4 104.7 10.2 M M
27000 -27.3 -17.1 255 37 19 6.8 3.7 39.1 102.4 9.4 M M
26000 -25.3 -13.5 250 37 19 6.8 3.7 38.0 100.4 8.6 M M
25000 -23.2 -9.8 245 38 20 6.7 3.7 37.0 98.6 7.8 M M
24000 -21.1 -6.0 245 36 19 7.5 4.1 36.0 96.8 7.1 M M
23000 -18.8 -1.8 250 33 17 7.5 4.1 35.2 95.3 6.5 M M
22000 -16.6 2.1 250 30 16 7.5 4.1 34.4 94.0 6.0 M M
21000 -14.7 5.5 255 28 15 6.1 3.3 33.2 91.7 5.0 M M
20000 -12.9 8.8 255 26 14 6.1 3.3 31.9 89.4 3.9 M M
19500 -12.0 10.4 260 25 13 6.1 3.3 31.3 88.3 3.4 M M
19000 -11.0 12.2 260 25 13 6.2 3.4 30.7 87.2 2.9 M M
18500 -10.1 13.8 260 24 12 6.3 3.5 30.1 86.1 2.4 M M
18000 -9.2 15.4 260 23 12 6.5 3.6 29.5 85.0 1.8 M M
17500 -8.2 17.2 260 22 11 7.5 4.1 29.0 84.2 1.4 M M
17000 -7.1 19.2 260 21 11 7.5 4.1 28.6 83.5 1.1 M M
16500 -6.0 21.2 260 20 10 7.4 4.0 28.2 82.8 0.7 M M
16000 -4.9 23.2 260 19 10 7.4 4.1 27.8 82.1 0.3 M M
15500 -3.3 26.1 265 18 9 8.0 4.4 27.3 81.1 -0.3 909 4.6
15000 -2.1 28.2 265 16 8 8.0 4.4 27.0 80.6 -0.6 860 4.4
14500 -1.0 30.2 270 15 8 8.1 4.5 26.7 80.1 -0.9 810 4.1
14000 0.2 32.4 275 15 8 8.2 4.5 26.4 79.6 -1.2 760 3.9
13500 1.4 34.5 280 14 7 8.1 4.5 26.2 79.2 -1.4 709 3.6
13000 2.6 36.7 285 13 7 8.1 4.5 25.9 78.7 -1.7 659 3.3
12500 3.8 38.8 295 12 6 8.3 4.6 25.7 78.2 -2.0 609 3.1
12000 5.0 41.0 300 12 6 8.5 4.7 25.5 77.8 -2.2 556 2.8
11500 6.3 43.3 310 12 6 8.3 4.6 25.3 77.5 -2.4 503 2.6
11000 7.5 45.5 315 12 6 7.8 4.3 25.0 77.0 -2.7 452 2.3
10500 8.7 47.7 320 12 6 5.2 2.9 24.7 76.5 -2.9 401 2.0
10250 9.0 48.2 320 12 6 4.9 2.7 24.2 75.6 -3.4 386 2.0
10000 9.6 49.3 320 12 6 10.3 5.6 24.1 75.4 -3.5 360 1.8
9750 10.4 50.7 325 12 6 11.7 6.4 24.2 75.6 -3.4 328 1.7
9500 11.3 52.3 325 12 6 9.1 5.0 24.3 75.8 -3.3 296 1.5
9250 11.8 53.2 325 12 6 6.0 3.3 24.1 75.4 -3.5 273 1.4
9000 12.3 54.1 330 12 6 8.8 4.8 23.9 75.0 -3.8 250 1.3
8750 13.1 55.6 330 12 6 11.0 6.1 23.9 75.1 -3.7 219 1.1
8500 13.8 56.8 330 13 6 8.6 4.7 24.0 75.1 -3.7 189 1.0
8250 14.4 57.9 330 13 7 7.1 3.9 23.8 74.8 -3.9 165 0.8
8000 14.9 58.8 330 13 7 7.7 4.2 23.6 74.5 -4.1 142 0.7
7750 15.5 59.9 330 13 7 7.6 4.2 23.5 74.2 -4.3 117 0.6
7500 16.0 60.8 330 12 6 6.7 3.6 23.3 73.9 -4.5 93 0.5
7250 16.5 61.7 325 12 6 5.7 3.1 23.0 73.4 -4.7 72 0.4
7000 17.0 62.6 320 11 6 7.2 3.9 22.7 72.9 -5.0 51 0.3
6750 17.5 63.5 320 11 6 5.3 2.9 22.5 72.5 -5.3 28 0.1
6500 17.6 63.7 315 10 5 0.8 0.4 22.0 71.5 -5.8 16 0.1
6250 17.7 63.9 310 9 5 2.7 1.5 21.3 70.4 -6.5 6 0.0
6000 17.8 64.0 305 8 4 -5.2 -2.9 20.7 69.2 -7.2 M M
5750 16.6 61.9 290 8 4 -26.7 -14.6 18.7 65.7 -9.1 25 0.1
5500 14.0 57.2 255 5 3 -37.9 -20.8 15.4 59.8 -12.5 97 0.5
* * * * * * Numerical weather prediction model forecast data valid * * * * * *
10/07/2024 at 0900 MDT | 10/07/2024 at 1200 MDT
|
CAPE... 0.0 LI... +1.3 | CAPE... 0.0 LI... +1.3
CINH... 0.0 K Index... +14.6 | CINH... 0.0 K Index... +5.5
|
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 -64.0 -83.2 285 25 13 3.0 1.7 | -64.0 -83.2 270 26 13 3.1 1.7
45000 -58.3 -72.9 280 34 17 6.2 3.4 | -58.3 -72.9 270 33 17 5.9 3.2
40000 -48.9 -56.0 270 38 19 3.7 2.0 | -49.3 -56.7 265 33 17 3.3 1.8
38000 -46.6 -51.9 270 36 19 3.8 2.1 | -47.3 -53.1 265 31 16 3.4 1.9
36000 -44.3 -47.7 275 35 18 3.8 2.1 | -45.2 -49.4 270 30 15 3.5 1.9
34000 -41.0 -41.8 275 33 17 6.2 3.4 | -41.9 -43.4 275 28 14 6.4 3.5
32000 -37.3 -35.1 275 30 16 6.2 3.4 | -38.1 -36.6 285 26 14 6.4 3.5
30000 -33.5 -28.3 275 28 14 6.4 3.5 | -34.0 -29.2 290 24 13 7.0 3.8
29000 -31.1 -24.0 280 26 13 6.4 3.5 | -31.9 -25.4 295 23 12 7.0 3.8
28000 -29.1 -20.4 280 25 13 6.5 3.6 | -29.3 -20.7 300 22 11 7.1 3.9
27000 -27.2 -17.0 280 24 12 6.6 3.6 | -27.1 -16.8 300 22 11 7.4 4.1
26000 -25.2 -13.4 280 23 12 6.6 3.6 | -24.9 -12.8 300 21 11 7.4 4.1
25000 -23.2 -9.8 275 23 12 6.6 3.6 | -22.7 -8.9 300 21 11 7.4 4.1
24000 -21.3 -6.3 270 23 12 6.5 3.6 | -20.6 -5.1 295 21 11 7.0 3.8
23000 -19.3 -2.7 265 23 12 6.5 3.6 | -18.5 -1.3 290 21 11 7.0 3.8
22000 -17.4 0.7 260 24 12 6.6 3.6 | -16.4 2.5 285 22 11 7.1 3.9
21000 -15.8 3.6 260 23 12 5.2 2.8 | -15.0 5.0 280 22 11 3.9 2.1
20000 -14.3 6.3 260 21 11 5.3 2.9 | -13.8 7.2 270 22 11 3.9 2.2
19500 -13.5 7.7 260 20 10 5.2 2.9 | -13.3 8.1 265 22 11 3.9 2.1
19000 -12.7 9.1 265 19 10 6.7 3.7 | -12.6 9.3 265 22 11 5.7 3.1
18500 -11.6 11.1 270 18 9 7.1 3.9 | -11.7 10.9 265 21 11 6.2 3.4
18000 -10.6 12.9 275 17 9 7.3 4.0 | -10.8 12.6 265 19 10 6.4 3.5
17500 -9.4 15.1 280 17 9 8.4 4.6 | -9.7 14.5 270 18 9 7.8 4.3
17000 -8.2 17.2 285 17 9 8.3 4.6 | -8.6 16.5 275 17 9 7.7 4.2
16500 -7.0 19.4 285 17 9 8.1 4.4 | -7.4 18.7 280 16 8 8.0 4.4
16000 -5.8 21.6 290 17 9 8.1 4.4 | -6.2 20.8 285 15 8 8.1 4.4
15500 -4.6 23.7 290 18 9 8.2 4.5 | -5.0 23.0 290 15 8 8.2 4.5
15000 -2.8 27.0 295 17 9 8.2 4.5 | -3.8 25.2 290 15 8 8.3 4.6
14500 -1.6 29.1 295 16 8 8.5 4.7 | -2.0 28.4 295 15 8 9.0 4.9
14000 -0.4 31.3 295 15 8 8.5 4.7 | -0.7 30.7 300 15 8 9.1 5.0
13500 0.9 33.6 300 15 8 8.9 4.9 | 0.7 33.3 300 16 8 9.0 4.9
13000 2.2 36.0 300 14 7 9.0 5.0 | 2.0 35.6 300 17 9 8.9 4.9
12500 3.6 38.5 305 14 7 8.7 4.8 | 3.2 37.8 305 18 9 8.7 4.8
12000 4.8 40.6 305 14 7 8.4 4.6 | 4.5 40.1 305 18 9 8.6 4.7
11500 6.1 43.0 305 13 7 8.3 4.6 | 5.8 42.4 305 18 9 8.6 4.7
11000 7.3 45.1 310 13 7 8.0 4.4 | 7.0 44.6 305 18 9 8.3 4.5
10500 8.5 47.3 310 12 6 4.8 2.6 | 8.3 46.9 305 18 9 4.0 2.2
10250 8.7 47.7 310 12 6 4.9 2.7 | 8.4 47.1 305 17 9 3.8 2.1
10000 9.4 48.9 310 12 6 11.4 6.2 | 9.0 48.2 305 16 8 11.2 6.2
9750 10.3 50.5 315 12 6 12.7 7.0 | 9.8 49.6 310 14 7 11.7 6.4
9500 11.1 52.0 315 11 6 9.2 5.0 | 10.6 51.1 310 12 6 9.4 5.2
9250 11.6 52.9 315 11 6 5.3 2.9 | 11.2 52.2 310 12 6 7.1 3.9
9000 12.1 53.8 315 11 6 9.1 5.0 | 11.8 53.2 310 11 6 9.9 5.4
8750 12.9 55.2 315 10 5 11.2 6.2 | 12.6 54.7 310 11 5 11.4 6.2
8500 13.7 56.7 315 10 5 8.7 4.8 | 13.4 56.1 310 10 5 9.8 5.4
8250 14.3 57.7 315 10 5 7.3 4.0 | 14.1 57.4 310 10 5 8.9 4.9
8000 14.8 58.6 315 10 5 8.4 4.6 | 14.8 58.6 310 10 5 9.9 5.4
7750 15.5 59.9 315 10 5 9.3 5.1 | 15.6 60.1 310 10 5 10.7 5.9
7500 16.2 61.2 315 10 5 8.5 4.7 | 16.3 61.3 310 10 5 10.1 5.5
7250 16.8 62.2 315 10 5 7.9 4.3 | 17.1 62.8 310 10 5 9.7 5.3
7000 17.4 63.3 310 10 5 8.6 4.7 | 17.8 64.0 310 10 5 10.2 5.6
6750 18.0 64.4 310 10 5 7.3 4.0 | 18.6 65.5 310 10 5 10.4 5.7
6500 18.4 65.1 310 11 6 4.7 2.6 | 19.3 66.7 310 9 5 10.1 5.6
6250 18.9 66.0 305 11 6 8.0 4.4 | 20.1 68.2 310 9 5 9.9 5.4
6000 19.3 66.7 305 12 6 -3.4 -1.9 | 20.9 69.6 310 9 5 10.8 5.9
5750 18.3 64.9 290 9 5 -14.9 -8.2 | 21.8 71.2 310 9 5 16.2 8.9
5500 17.7 63.9 275 6 3 -0.1 -0.1 | 23.3 73.9 315 9 4 22.5 12.4
10/07/2024 at 1500 MDT | 10/07/2024 at 1800 MDT
|
CAPE... 0.0 LI... +2.1 | CAPE... 0.0 LI... +2.2
CINH... 0.0 K Index... +0.4 | CINH... 0.0 K Index... +13.2
|
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 -63.0 -81.4 270 27 14 3.1 1.7 | -62.1 -79.8 275 24 12 3.3 1.8
45000 -57.6 -71.7 270 33 17 5.0 2.8 | -56.8 -70.2 275 29 15 4.3 2.4
40000 -50.2 -58.4 260 33 17 3.2 1.7 | -50.3 -58.5 270 31 16 3.1 1.7
38000 -48.4 -55.1 265 32 16 2.9 1.6 | -48.7 -55.7 270 32 16 2.7 1.5
36000 -46.7 -52.1 265 31 16 2.9 1.6 | -46.9 -52.4 275 32 17 2.8 1.5
34000 -43.0 -45.4 275 29 15 6.6 3.6 | -43.4 -46.1 275 32 16 6.8 3.7
32000 -39.0 -38.2 280 29 15 6.6 3.6 | -39.3 -38.7 275 31 16 6.8 3.8
30000 -34.6 -30.3 285 27 14 7.7 4.2 | -35.0 -31.0 280 29 15 7.5 4.1
29000 -32.3 -26.1 285 26 13 7.7 4.2 | -32.7 -26.9 280 28 14 7.5 4.1
28000 -30.0 -22.0 285 25 13 7.7 4.2 | -30.5 -22.9 285 27 14 7.5 4.1
27000 -27.7 -17.9 290 24 12 7.5 4.1 | -28.3 -18.9 285 26 13 7.0 3.8
26000 -25.5 -13.9 290 23 12 7.5 4.1 | -26.2 -15.2 285 25 13 7.0 3.8
25000 -23.2 -9.8 290 22 11 7.5 4.1 | -24.1 -11.4 285 23 12 7.0 3.8
24000 -21.1 -6.0 290 22 11 7.0 3.8 | -22.1 -7.8 285 22 12 6.5 3.6
23000 -19.0 -2.2 295 22 11 7.0 3.8 | -20.2 -4.4 290 22 11 6.5 3.6
22000 -16.9 1.6 300 22 11 7.2 4.0 | -18.2 -0.8 295 22 11 6.5 3.6
21000 -15.2 4.6 300 22 11 4.9 2.7 | -16.3 2.7 300 22 11 6.4 3.5
20000 -13.8 7.2 305 22 11 4.9 2.7 | -14.4 6.1 300 22 11 6.5 3.5
19500 -13.0 8.6 305 22 11 5.0 2.7 | -13.4 7.9 305 22 12 6.5 3.5
19000 -12.3 9.9 305 22 11 5.4 2.9 | -12.4 9.7 305 23 12 6.3 3.4
18500 -11.5 11.3 300 21 11 5.6 3.1 | -11.6 11.1 300 22 11 6.2 3.4
18000 -10.6 12.9 300 20 10 5.7 3.1 | -10.7 12.7 300 22 11 6.2 3.4
17500 -8.9 16.0 300 19 10 8.2 4.5 | -9.0 15.8 295 21 11 8.5 4.6
17000 -7.7 18.1 305 18 9 8.3 4.6 | -7.7 18.1 295 20 10 8.6 4.7
16500 -6.4 20.5 305 18 10 8.6 4.7 | -6.5 20.3 295 19 10 8.3 4.6
16000 -5.1 22.8 305 19 10 8.6 4.7 | -5.3 22.5 300 18 9 8.3 4.6
15500 -3.9 25.0 310 19 10 8.4 4.6 | -4.0 24.8 300 17 9 9.2 5.0
15000 -2.6 27.3 310 20 10 8.4 4.6 | -2.6 27.3 300 16 8 9.2 5.1
14500 -1.3 29.7 310 20 10 8.6 4.7 | -1.3 29.7 305 15 8 9.0 4.9
14000 -0.1 31.8 310 20 10 8.6 4.7 | 0.1 32.2 305 14 7 8.9 4.9
13500 1.2 34.2 310 19 10 8.8 4.8 | 1.4 34.5 310 13 7 8.6 4.7
13000 2.5 36.5 310 18 9 8.9 4.9 | 2.6 36.7 315 12 6 8.3 4.6
12500 3.8 38.8 310 17 9 8.5 4.7 | 3.9 39.0 320 11 5 8.4 4.6
12000 4.9 40.8 315 14 7 7.8 4.3 | 5.1 41.2 330 10 5 8.7 4.8
11500 6.0 42.8 315 12 6 8.1 4.4 | 6.5 43.7 340 9 5 8.6 4.7
11000 7.3 45.1 320 11 5 8.5 4.7 | 7.7 45.9 345 8 4 8.1 4.4
10500 8.6 47.5 325 9 5 5.4 2.9 | 9.0 48.2 355 7 4 5.5 3.0
10250 8.8 47.8 325 9 5 5.8 3.2 | 9.3 48.7 355 7 4 5.3 2.9
10000 9.6 49.3 325 9 5 12.1 6.7 | 9.9 49.8 355 7 4 10.3 5.6
9750 10.5 50.9 325 9 5 12.9 7.1 | 10.7 51.3 360 7 4 11.0 6.0
9500 11.4 52.5 325 9 5 10.5 5.8 | 11.5 52.7 360 7 4 9.5 5.2
9250 12.0 53.6 325 9 5 7.6 4.2 | 12.1 53.8 005 7 4 7.5 4.1
9000 12.7 54.9 325 9 4 10.1 5.5 | 12.7 54.9 005 7 4 9.3 5.1
8750 13.5 56.3 325 9 4 11.9 6.5 | 13.4 56.1 005 7 4 11.0 6.0
8500 14.4 57.9 325 9 4 10.4 5.7 | 14.2 57.6 005 7 4 9.9 5.4
8250 15.1 59.2 325 9 4 9.5 5.2 | 14.9 58.8 005 7 4 9.1 5.0
8000 15.8 60.4 325 9 4 10.0 5.5 | 15.6 60.1 005 7 4 9.7 5.3
7750 16.6 61.9 325 9 4 10.2 5.6 | 16.4 61.5 005 7 4 10.3 5.7
7500 17.4 63.3 325 9 4 10.1 5.5 | 17.2 63.0 005 7 4 9.8 5.4
7250 18.1 64.6 325 9 4 10.0 5.5 | 17.9 64.2 360 7 4 9.3 5.1
7000 18.9 66.0 325 8 4 9.9 5.4 | 18.6 65.5 360 7 4 9.8 5.4
6750 19.6 67.3 325 8 4 10.0 5.5 | 19.3 66.7 360 7 4 10.4 5.7
6500 20.4 68.7 325 8 4 10.5 5.7 | 20.1 68.2 360 7 4 10.1 5.5
6250 21.2 70.2 325 8 4 10.5 5.8 | 20.9 69.6 360 7 4 9.8 5.4
6000 21.9 71.4 325 8 4 10.4 5.7 | 21.6 70.9 355 7 4 9.9 5.4
5750 22.8 73.0 325 8 4 15.0 8.2 | 22.3 72.1 355 6 3 8.2 4.5
5500 24.3 75.7 325 8 4 23.0 12.6 | 22.8 73.0 355 5 3 5.5 3.0
________________________________________________________________________________
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 near the old Stapleton
Airport site in Denver, Colorado at
North Latitude: 39 deg 46 min 5.016 sec
West Longitude: 104 deg 52 min 9.984 sec
Elevation: 5285 feet (1611 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.
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