Soaring Guidance
Issued by NWS Denver/Boulder, CO
Issued by NWS Denver/Boulder, CO
949
UXUS97 KBOU 070040
SRGBOU
Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1739 MST Wednesday, November 6, 2024
This forecast is for Thursday, November 7, 2024:
If the trigger temperature of 45.1 F/7.3 C is reached...then
Thermal Soaring Index....................... Poor
Maximum rate of lift........................ 0 ft/min (0.0 m/s)
Maximum height of thermals.................. 8021 ft MSL (2707 ft AGL)
Forecast maximum temperature................... 36.0 F/2.7 C
Time of trigger temperature.................... None
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................. 6874 ft MSL (1560 ft AGL)
Thermal soaring outlook for Friday 11/08....... Poor
Wave Soaring Index............................. Poor
Wave Soaring Index trend (to 1700 MST)......... No change
Height of stable layer (12-18K ft MSL)......... 17834 ft MSL (12520 ft AGL)
Weak PVA/NVA (through 1700 MST)................ Neither
Potential height of wave....................... 26426 ft MSL (21112 ft AGL)
Wave soaring outlook for Friday 11/08.......... Poor
Remarks...
Sunrise/Sunset.................... 06:35:55 / 16:50:24 MST
Total possible sunshine........... 10 hr 14 min 29 sec (614 min 29 sec)
Altitude of sun at 11:43:09 MST... 33.51 degrees
Upper air data from numerical model forecast valid on 11/07/2024 at 0500 MST
Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 13926 ft MSL (8612 ft AGL)
Lifted condensation level....... 8891 ft MSL (3576 ft AGL)
Lifted index.................... +14.5
K index......................... +16.4
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 -57.5 -71.5 085 14 7 2.4 1.3 M M M M M
45000 -53.9 -65.0 080 18 9 2.3 1.3 M M M M M
40000 -50.3 -58.5 085 15 8 2.3 1.3 M M M M M
38000 -49.6 -57.3 105 10 5 0.4 0.2 M M M M M
36000 -49.4 -56.9 175 9 5 0.4 0.2 M M M M M
34000 -48.9 -56.0 200 19 10 3.0 1.6 M M M M M
32000 -47.3 -53.1 200 41 21 2.8 1.5 M M M M M
30000 -45.1 -49.2 200 59 30 7.7 4.2 32.0 89.5 22.2 M M
29000 -42.4 -44.3 195 60 31 7.4 4.1 30.6 87.1 21.6 M M
28000 -40.2 -40.4 190 61 31 7.4 4.1 29.8 85.6 21.2 M M
27000 -37.9 -36.2 185 62 32 8.4 4.6 29.0 84.2 20.8 M M
26000 -35.3 -31.5 185 59 30 8.7 4.8 28.5 83.3 20.7 M M
25000 -32.8 -27.0 180 56 29 8.7 4.8 28.1 82.6 20.6 M M
24000 -30.2 -22.4 180 53 27 8.2 4.5 27.8 82.1 20.6 M M
23000 -27.9 -18.2 180 51 26 7.7 4.2 26.9 80.5 20.1 M M
22000 -25.6 -14.1 180 50 26 7.7 4.2 26.2 79.2 19.7 M M
21000 -23.4 -10.1 180 48 25 6.7 3.7 25.5 77.9 19.3 M M
20000 -21.4 -6.5 175 44 23 6.6 3.6 24.3 75.7 18.5 M M
19500 -20.5 -4.9 175 43 22 6.6 3.6 23.7 74.7 18.1 M M
19000 -19.5 -3.1 170 41 21 6.6 3.6 23.2 73.8 17.8 M M
18500 -18.6 -1.5 170 39 20 2.8 1.6 22.6 72.7 17.3 M M
18000 -18.5 -1.3 160 30 15 0.9 0.5 21.0 69.8 16.1 M M
17500 -18.4 -1.1 145 22 11 1.3 0.7 19.5 67.0 14.8 M M
17000 -17.7 0.1 135 19 10 7.2 3.9 18.6 65.5 14.1 M M
16500 -16.7 1.9 130 16 8 6.7 3.7 18.1 64.6 13.8 M M
16000 -15.6 3.9 130 15 8 7.8 4.3 17.7 63.8 13.4 M M
15500 -13.9 7.0 130 16 8 7.9 4.3 17.2 63.0 13.1 M M
15000 -12.8 9.0 130 16 8 6.8 3.7 16.8 62.2 12.8 M M
14500 -11.8 10.8 125 15 8 7.0 3.8 16.3 61.4 12.4 M M
14000 -10.9 12.4 120 15 8 6.2 3.4 15.8 60.4 12.0 M M
13500 -10.0 14.0 115 14 7 6.3 3.5 15.2 59.4 11.5 M M
13000 -9.1 15.6 110 14 7 5.2 2.9 14.6 58.2 10.9 M M
12500 -8.3 17.1 115 14 7 5.1 2.8 13.8 56.9 10.3 M M
12000 -7.6 18.3 115 14 7 6.2 3.4 13.1 55.7 9.7 M M
11500 -6.6 20.1 120 14 7 6.4 3.5 12.6 54.6 9.2 M M
11000 -5.8 21.6 115 15 8 4.5 2.4 11.9 53.5 8.6 M M
10500 -5.2 22.6 110 17 9 4.5 2.5 11.1 51.9 7.8 M M
10250 -4.9 23.2 110 18 9 3.7 2.0 10.6 51.1 7.4 M M
10000 -4.7 23.5 110 18 9 2.3 1.3 10.1 50.2 6.9 M M
9750 -4.6 23.7 105 18 10 -0.5 -0.3 9.4 49.0 6.3 M M
9500 -4.7 23.5 105 18 9 -2.2 -1.2 8.5 47.3 5.4 M M
9250 -4.9 23.2 100 17 9 -3.5 -1.9 7.6 45.6 4.6 M M
9000 -5.2 22.6 095 15 8 -5.4 -3.0 6.4 43.6 3.5 M M
8750 -5.6 21.9 090 13 7 -4.1 -2.3 5.3 41.5 2.5 M M
8500 -5.8 21.6 085 12 6 -2.1 -1.2 4.3 39.7 1.5 M M
8250 -5.9 21.4 075 10 5 -0.3 -0.2 3.4 38.2 0.7 M M
8000 -5.9 21.4 065 9 5 0.2 0.1 2.7 36.9 -0.0 271 1.4
7750 -5.9 21.4 055 8 4 -0.0 -0.0 2.0 35.5 -0.7 263 1.3
7500 -5.8 21.6 040 7 4 1.1 0.6 1.2 34.2 -1.4 255 1.3
7250 -5.7 21.7 025 7 4 2.3 1.2 0.6 33.1 -2.0 243 1.2
7000 -5.6 21.9 015 7 3 1.0 0.6 0.0 32.0 -2.6 232 1.2
6750 -5.4 22.3 360 7 4 4.7 2.6 -0.6 31.0 -3.2 220 1.1
6500 -4.8 23.4 355 7 3 8.4 4.6 -0.7 30.7 -3.4 196 1.0
6250 -4.3 24.3 350 6 3 7.1 3.9 -0.9 30.4 -3.6 171 0.9
6000 -3.7 25.3 345 6 3 8.6 4.7 -1.1 30.1 -3.7 147 0.7
5750 -3.0 26.6 345 5 3 10.4 5.7 -1.1 30.1 -3.7 118 0.6
5500 -2.2 28.0 345 4 2 9.6 5.3 -1.0 30.1 -3.7 89 0.4
* * * * * * Numerical weather prediction model forecast data valid * * * * * *
11/07/2024 at 0800 MST | 11/07/2024 at 1100 MST
|
CAPE... +6.1 LI... +3.0 | CAPE... +12.9 LI... +4.8
CINH... 0.0 K Index... +20.5 | CINH... 0.0 K Index... +18.5
|
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 -58.3 -72.9 095 13 7 2.4 1.3 | -57.9 -72.2 110 12 6 1.9 1.0
45000 -54.5 -66.1 085 22 11 2.5 1.4 | -54.8 -66.6 105 21 11 2.3 1.2
40000 -50.8 -59.4 100 20 10 2.5 1.4 | -51.5 -60.7 110 16 8 2.3 1.2
38000 -49.5 -57.1 105 18 9 2.0 1.1 | -50.5 -58.9 135 13 7 1.3 0.7
36000 -48.3 -54.9 105 16 8 2.0 1.1 | -49.7 -57.5 170 15 8 1.3 0.7
34000 -47.3 -53.1 125 14 7 0.4 0.2 | -48.7 -55.7 190 24 12 3.2 1.7
32000 -47.1 -52.8 175 26 13 0.5 0.3 | -46.8 -52.2 190 43 22 3.2 1.8
30000 -45.3 -49.5 185 40 20 7.9 4.4 | -43.7 -46.7 185 54 28 7.5 4.1
29000 -42.9 -45.2 180 39 20 8.0 4.4 | -41.5 -42.7 185 49 25 7.5 4.1
28000 -40.5 -40.9 175 38 19 8.0 4.4 | -39.2 -38.6 180 45 23 7.5 4.1
27000 -38.1 -36.6 170 37 19 9.0 4.9 | -36.9 -34.4 180 41 21 8.6 4.7
26000 -35.4 -31.7 175 38 19 9.0 4.9 | -34.3 -29.7 175 38 20 8.6 4.7
25000 -32.7 -26.9 180 38 20 9.0 5.0 | -31.8 -25.2 175 36 18 8.6 4.7
24000 -30.0 -22.0 180 39 20 8.5 4.7 | -29.2 -20.6 170 34 17 8.6 4.7
23000 -27.6 -17.7 180 39 20 8.3 4.5 | -26.6 -15.9 175 36 19 8.7 4.8
22000 -25.1 -13.2 180 39 20 8.3 4.5 | -24.1 -11.4 175 39 20 8.7 4.8
21000 -22.8 -9.0 180 38 20 6.5 3.6 | -21.7 -7.1 180 40 21 6.1 3.4
20000 -20.8 -5.4 170 37 19 6.7 3.7 | -19.8 -3.6 185 39 20 6.5 3.5
19500 -19.8 -3.6 165 37 19 6.7 3.7 | -18.8 -1.8 185 39 20 6.5 3.6
19000 -18.8 -1.8 160 37 19 6.8 3.7 | -17.9 -0.2 185 38 20 6.5 3.6
18500 -17.9 -0.2 155 37 19 5.5 3.0 | -16.9 1.6 190 38 19 6.5 3.6
18000 -17.1 1.2 150 36 19 5.3 2.9 | -16.0 3.2 190 36 19 6.5 3.6
17500 -16.4 2.5 145 36 18 5.4 2.9 | -15.0 5.0 190 35 18 6.4 3.5
17000 -15.5 4.1 140 34 17 5.6 3.1 | -14.1 6.6 185 34 17 6.2 3.4
16500 -14.7 5.5 135 31 16 5.6 3.1 | -13.2 8.2 180 32 17 6.2 3.4
16000 -13.9 7.0 130 29 15 5.9 3.2 | -11.8 10.8 170 31 16 6.4 3.5
15500 -13.0 8.6 130 28 14 5.9 3.2 | -10.9 12.4 165 30 16 6.3 3.5
15000 -11.7 10.9 125 27 14 6.3 3.4 | -10.0 14.0 165 29 15 5.4 2.9
14500 -10.8 12.6 120 26 14 6.3 3.5 | -9.3 15.3 160 27 14 5.7 3.1
14000 -9.9 14.2 120 26 13 5.1 2.8 | -8.8 16.2 160 24 13 1.2 0.6
13500 -9.2 15.4 115 25 13 5.0 2.8 | -8.5 16.7 160 22 11 1.4 0.8
13000 -8.3 17.1 110 24 12 7.0 3.8 | -8.1 17.4 155 21 11 3.5 1.9
12500 -7.3 18.9 110 23 12 6.9 3.8 | -7.6 18.3 155 20 10 3.2 1.8
12000 -6.3 20.7 110 23 12 6.5 3.5 | -7.0 19.4 145 20 10 6.4 3.5
11500 -5.4 22.3 110 22 11 6.6 3.6 | -6.0 21.2 140 21 11 6.6 3.6
11000 -4.5 23.9 110 22 12 5.3 2.9 | -5.2 22.6 135 22 11 4.2 2.3
10500 -3.8 25.2 110 23 12 5.5 3.0 | -4.6 23.7 130 23 12 4.5 2.5
10250 -3.4 25.9 110 23 12 4.2 2.3 | -4.3 24.3 125 24 12 3.1 1.7
10000 -3.2 26.2 110 24 12 2.8 1.5 | -4.2 24.4 130 25 13 1.9 1.0
9750 -3.0 26.6 110 25 13 1.2 0.6 | -4.0 24.8 130 25 13 3.1 1.7
9500 -3.0 26.6 110 27 14 -0.9 -0.5 | -3.7 25.3 130 27 14 3.3 1.8
9250 -3.2 26.2 110 28 14 -4.7 -2.6 | -3.5 25.7 130 28 14 2.7 1.5
9000 -3.6 25.5 110 27 14 -6.5 -3.6 | -3.3 26.1 130 29 15 2.3 1.3
8750 -4.1 24.6 110 27 14 -8.0 -4.4 | -3.1 26.4 130 30 15 2.9 1.6
8500 -4.6 23.7 105 25 13 -6.2 -3.4 | -3.0 26.6 130 30 16 -0.8 -0.5
8250 -4.8 23.4 105 22 11 -1.2 -0.7 | -3.3 26.1 130 28 14 -5.8 -3.2
8000 -4.9 23.2 095 19 10 -0.8 -0.4 | -3.7 25.3 130 24 12 -4.9 -2.7
7750 -5.0 23.0 090 16 8 -2.0 -1.1 | -4.1 24.6 130 21 11 -8.7 -4.8
7500 -5.2 22.6 080 13 7 -2.1 -1.2 | -4.7 23.5 130 15 8 -4.9 -2.7
7250 -5.2 22.6 075 10 5 -0.6 -0.3 | -4.7 23.5 130 11 5 2.3 1.3
7000 -5.3 22.5 065 7 3 -2.0 -1.1 | -4.7 23.5 145 6 3 -1.2 -0.7
6750 -5.4 22.3 040 4 2 2.0 1.1 | -4.6 23.7 200 3 1 5.8 3.2
6500 -5.0 23.0 035 3 2 6.6 3.6 | -3.9 25.0 235 3 1 11.0 6.0
6250 -4.6 23.7 015 3 1 5.5 3.0 | -3.2 26.2 260 4 2 8.4 4.6
6000 -4.1 24.6 345 2 1 7.4 4.1 | -2.6 27.3 275 5 3 9.1 5.0
5750 -3.5 25.7 335 2 1 10.9 6.0 | -1.9 28.6 275 5 3 11.4 6.3
5500 -2.6 27.3 325 2 1 11.8 6.5 | -0.9 30.4 280 4 2 15.9 8.7
11/07/2024 at 1400 MST | 11/07/2024 at 1700 MST
|
CAPE... +10.0 LI... +6.0 | CAPE... +0.7 LI... +5.7
CINH... 0.0 K Index... +16.9 | 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 -57.3 -71.1 120 9 5 2.4 1.3 | -58.4 -73.1 120 6 3 2.1 1.2
45000 -54.0 -65.2 115 16 8 0.9 0.5 | -55.0 -67.0 110 12 6 2.1 1.2
40000 -52.6 -62.7 115 19 10 0.9 0.5 | -51.9 -61.4 120 21 11 2.1 1.1
38000 -51.9 -61.4 135 18 9 1.5 0.8 | -50.9 -59.6 140 23 12 1.4 0.7
36000 -50.9 -59.6 165 22 11 1.5 0.8 | -50.1 -58.2 165 28 15 1.4 0.7
34000 -49.7 -57.5 175 30 15 3.6 2.0 | -49.0 -56.2 170 36 18 3.2 1.7
32000 -47.2 -53.0 165 39 20 3.7 2.0 | -46.8 -52.2 155 43 22 3.2 1.8
30000 -43.7 -46.7 160 45 23 9.5 5.2 | -43.5 -46.3 150 46 24 9.3 5.1
29000 -40.9 -41.6 160 44 23 9.5 5.2 | -40.7 -41.3 150 45 23 9.3 5.1
28000 -38.0 -36.4 165 43 22 9.5 5.2 | -38.0 -36.4 150 43 22 9.3 5.1
27000 -35.3 -31.5 165 42 21 8.1 4.4 | -35.3 -31.5 150 42 21 8.1 4.4
26000 -32.8 -27.0 165 40 20 8.3 4.5 | -32.8 -27.0 145 42 21 8.2 4.5
25000 -30.3 -22.5 165 38 19 8.3 4.5 | -30.3 -22.5 145 41 21 8.3 4.5
24000 -27.9 -18.2 165 36 18 7.8 4.3 | -27.9 -18.2 145 41 21 8.0 4.4
23000 -25.6 -14.1 170 35 18 7.7 4.2 | -25.5 -13.9 145 41 21 7.9 4.4
22000 -23.3 -9.9 170 33 17 7.7 4.2 | -23.2 -9.8 145 41 21 8.0 4.4
21000 -21.0 -5.8 170 33 17 7.4 4.1 | -20.9 -5.6 145 39 20 6.9 3.8
20000 -18.8 -1.8 170 33 17 7.5 4.1 | -18.8 -1.8 145 36 19 7.0 3.9
19500 -17.7 0.1 170 33 17 7.5 4.1 | -17.8 -0.0 145 35 18 7.1 3.9
19000 -16.6 2.1 170 33 17 7.5 4.1 | -16.8 1.8 150 34 17 7.0 3.9
18500 -15.6 3.9 170 33 17 6.9 3.8 | -15.7 3.7 150 33 17 7.5 4.1
18000 -14.6 5.7 170 34 18 6.8 3.7 | -14.6 5.7 150 33 17 7.6 4.1
17500 -13.6 7.5 170 35 18 7.0 3.8 | -13.5 7.7 150 33 17 7.3 4.0
17000 -12.5 9.5 165 36 19 7.2 4.0 | -12.5 9.5 150 33 17 6.8 3.8
16500 -11.5 11.3 165 38 19 7.4 4.1 | -11.0 12.2 155 33 17 6.5 3.5
16000 -10.1 13.8 160 38 20 6.1 3.4 | -10.1 13.8 155 33 17 6.1 3.3
15500 -9.2 15.4 160 39 20 5.9 3.2 | -9.2 15.4 155 33 17 6.0 3.3
15000 -8.4 16.9 160 39 20 4.5 2.5 | -8.4 16.9 155 33 17 5.5 3.0
14500 -7.8 18.0 160 39 20 4.7 2.6 | -7.6 18.3 160 33 17 5.6 3.1
14000 -7.2 19.0 160 38 20 3.1 1.7 | -6.8 19.8 160 34 17 5.2 2.8
13500 -6.7 19.9 160 36 19 3.3 1.8 | -6.0 21.2 160 35 18 5.3 2.9
13000 -6.3 20.7 160 34 18 2.9 1.6 | -5.4 22.3 160 36 18 3.7 2.0
12500 -5.8 21.6 160 32 16 3.1 1.7 | -4.8 23.4 160 36 19 4.0 2.2
12000 -5.5 22.1 160 28 14 1.1 0.6 | -4.5 23.9 160 36 18 -0.7 -0.4
11500 -5.3 22.5 160 22 11 0.7 0.4 | -4.7 23.5 160 33 17 -1.2 -0.7
11000 -5.0 23.0 160 18 9 4.5 2.4 | -4.8 23.4 165 30 16 -0.1 -0.0
10500 -4.3 24.3 165 16 8 4.9 2.7 | -4.7 23.5 170 26 13 -0.2 -0.1
10250 -4.0 24.8 165 15 8 2.9 1.6 | -4.7 23.5 170 24 12 0.7 0.4
10000 -3.9 25.0 165 16 8 1.1 0.6 | -4.6 23.7 170 23 12 2.5 1.4
9750 -3.7 25.3 165 17 9 3.1 1.7 | -4.3 24.3 170 23 12 4.0 2.2
9500 -3.5 25.7 170 19 10 3.7 2.0 | -4.0 24.8 170 22 12 4.7 2.6
9250 -3.2 26.2 170 21 11 2.6 1.4 | -3.7 25.3 170 22 11 4.6 2.5
9000 -3.1 26.4 170 22 11 1.8 1.0 | -3.3 26.1 170 22 11 4.3 2.3
8750 -2.9 26.8 170 23 12 2.7 1.5 | -3.0 26.6 170 22 11 6.7 3.7
8500 -2.7 27.1 170 25 13 2.4 1.3 | -2.4 27.7 170 22 11 7.6 4.2
8250 -2.6 27.3 165 25 13 0.9 0.5 | -2.0 28.4 170 22 11 5.2 2.9
8000 -2.5 27.5 165 25 13 1.0 0.6 | -1.6 29.1 170 22 12 4.6 2.5
7750 -2.5 27.5 160 25 13 -0.1 -0.0 | -1.3 29.7 170 23 12 5.7 3.1
7500 -2.6 27.3 160 23 12 -3.1 -1.7 | -0.9 30.4 170 23 12 1.0 0.6
7250 -2.8 27.0 160 19 10 -3.3 -1.8 | -1.1 30.0 170 20 10 -3.2 -1.7
7000 -3.1 26.4 165 15 8 -5.4 -2.9 | -1.2 29.8 175 18 9 -2.4 -1.3
6750 -3.4 25.9 175 11 5 3.1 1.7 | -1.4 29.5 180 16 8 -1.4 -0.8
6500 -2.7 27.1 175 8 4 10.0 5.5 | -1.4 29.5 185 13 7 1.2 0.7
6250 -2.2 28.0 180 6 3 6.2 3.4 | -1.3 29.7 185 11 6 0.9 0.5
6000 -1.7 28.9 195 4 2 8.0 4.4 | -1.2 29.8 185 8 4 3.4 1.9
5750 -1.0 30.2 200 3 2 9.9 5.5 | -0.8 30.6 190 6 3 8.3 4.5
5500 -0.2 31.6 195 2 1 11.7 6.4 | -0.2 31.6 185 5 2 8.3 4.5
________________________________________________________________________________
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.
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