Soaring Guidance Issued by NWS Pueblo, CO
000
UXUS97 KPUB 151208
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0608 MDT Friday, March 15, 2024
This forecast is for the Air Force Academy for Friday, March 15, 2024:
If the trigger temperature of 34.7 F/1.5 C is reached...then
Thermal Soaring Index....................... Poor
Maximum rate of lift........................ 0 ft/min (0.0 m/s)
Maximum height of thermals.................. 11638 ft MSL (4044 ft AGL)
Forecast maximum temperature................... 35.0 F/2.1 C
Time of trigger temperature.................... 1400 MDT
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................. 10314 ft MSL (2720 ft AGL)
Thermal soaring outlook for Saturday 03/16..... Poor
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 07:09:12 / 19:06:41 MDT
Total possible sunshine........... 11 hr 57 min 28 sec (717 min 28 sec)
Altitude of sun at 13:07:57 MDT... 49.26 degrees
Upper air data from numerical model forecast valid on 03/15/2024 at 0600 MDT
Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 10630 ft MSL (3036 ft AGL)
Lifted condensation level....... 11708 ft MSL (4114 ft AGL)
Lifted index.................... +6.5
K index......................... +10.6
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 -54.9 -66.8 250 19 10 1.7 0.9 M M M M M
45000 -52.4 -62.3 255 24 12 1.8 1.0 M M M M M
40000 -56.0 -68.8 220 35 18 -2.6 -1.4 M M M M M
38000 -56.9 -70.4 220 38 19 0.2 0.1 M M M M M
36000 -56.8 -70.2 235 37 19 0.2 0.1 M M M M M
34000 -56.6 -69.9 245 39 20 3.3 1.8 M M M M M
32000 -53.6 -64.5 240 42 21 5.0 2.7 M M M M M
30000 -50.4 -58.7 240 44 23 8.6 4.7 18.0 64.4 12.5 M M
29000 -47.8 -54.0 240 43 22 8.6 4.7 17.4 63.3 12.2 M M
28000 -45.2 -49.4 235 41 21 8.7 4.7 17.0 62.6 12.0 M M
27000 -42.6 -44.7 235 40 21 8.6 4.7 16.7 62.1 11.9 M M
26000 -39.8 -39.6 235 39 20 9.8 5.4 16.6 61.8 12.0 M M
25000 -36.8 -34.2 235 39 20 9.8 5.4 16.6 61.8 12.1 M M
24000 -33.9 -29.0 230 39 20 9.9 5.4 16.7 62.0 12.3 M M
23000 -30.5 -22.9 230 38 19 9.0 5.0 16.4 61.4 12.2 M M
22000 -27.8 -18.0 230 36 19 9.1 5.0 16.1 61.0 12.2 M M
21000 -25.2 -13.4 225 35 18 7.3 4.0 15.8 60.5 12.0 M M
20000 -23.0 -9.4 220 34 17 7.2 3.9 14.9 58.7 11.3 M M
19500 -22.0 -7.6 220 33 17 7.2 3.9 14.4 58.0 11.0 M M
19000 -20.9 -5.6 220 32 17 7.2 3.9 14.0 57.2 10.7 M M
18500 -19.8 -3.6 220 31 16 7.5 4.1 13.6 56.5 10.4 M M
18000 -18.7 -1.7 215 30 15 7.5 4.1 13.2 55.8 10.1 M M
17500 -17.6 0.3 210 29 15 6.8 3.7 12.9 55.2 9.8 M M
17000 -16.9 1.6 200 26 13 3.9 2.2 12.1 53.7 9.1 M M
16500 -16.3 2.7 195 22 12 4.1 2.3 11.1 52.0 8.3 M M
16000 -15.7 3.7 185 20 10 3.8 2.1 10.2 50.3 7.5 M M
15500 -15.1 4.8 175 18 9 3.8 2.1 9.2 48.5 6.6 M M
15000 -14.5 5.9 165 17 9 5.5 3.0 8.3 46.9 5.8 M M
14500 -13.6 7.5 160 17 9 5.9 3.2 7.7 45.8 5.2 M M
14000 -12.7 9.1 150 17 9 5.9 3.2 7.1 44.7 4.7 M M
13500 -11.8 10.8 140 15 8 5.8 3.2 6.4 43.6 4.2 M M
13000 -10.9 12.4 125 14 7 4.5 2.5 5.8 42.5 3.7 M M
12500 -10.4 13.3 125 8 4 2.1 1.2 4.8 40.6 2.7 M M
12000 -10.4 13.3 150 5 3 -0.2 -0.1 3.3 38.0 1.3 M M
11750 -10.4 13.3 165 6 3 -0.9 -0.5 2.5 36.5 0.5 M M
11500 -10.5 13.1 180 6 3 -0.4 -0.2 1.7 35.0 -0.3 347 1.8
11250 -10.6 12.9 190 8 4 -1.9 -1.0 0.9 33.5 -1.1 342 1.7
11000 -10.7 12.7 190 8 4 2.1 1.1 -0.0 32.0 -2.0 338 1.7
10750 -10.3 13.5 180 9 5 6.3 3.5 -0.3 31.4 -2.3 318 1.6
10500 -9.9 14.2 175 10 5 5.2 2.8 -0.7 30.8 -2.7 299 1.5
10250 -9.5 14.9 170 11 6 5.6 3.1 -1.0 30.2 -3.0 280 1.4
10000 -9.1 15.6 165 12 6 5.3 2.9 -1.3 29.6 -3.4 260 1.3
9750 -8.7 16.3 155 11 6 5.0 2.7 -1.7 28.9 -3.7 242 1.2
9500 -8.4 16.9 140 11 6 5.3 2.9 -2.1 28.3 -4.1 223 1.1
9250 -8.0 17.6 130 12 6 4.5 2.4 -2.4 27.6 -4.5 204 1.0
9000 -7.6 18.3 125 12 6 7.3 4.0 -2.8 27.0 -4.8 186 0.9
8750 -6.9 19.6 115 12 6 10.1 5.6 -2.8 27.0 -4.9 158 0.8
8500 -6.2 20.8 110 12 6 9.4 5.2 -2.8 26.9 -4.9 130 0.7
8250 -5.6 21.9 105 12 6 9.0 4.9 -2.8 26.9 -5.0 102 0.5
8000 -4.9 23.2 105 11 6 9.0 4.9 -2.9 26.8 -5.1 75 0.4
7750 -4.2 24.4 100 9 5 10.4 5.7 -2.9 26.8 -5.2 47 0.2
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 * * * * * *
03/15/2024 at 0900 MDT | 03/15/2024 at 1200 MDT
|
CAPE... +11.2 LI... +3.3 | CAPE... +9.4 LI... +1.3
CINH... 0.0 K Index... +11.6 | CINH... 0.0 K Index... +15.1
|
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 -56.3 -69.3 250 18 9 2.0 1.1 | -56.5 -69.7 255 27 14 1.7 0.9
45000 -53.2 -63.8 260 15 8 1.2 0.7 | -53.8 -64.8 250 26 13 0.8 0.5
40000 -56.2 -69.2 235 28 15 -2.1 -1.1 | -57.4 -71.3 230 35 18 -2.5 -1.4
38000 -56.8 -70.2 230 33 17 0.7 0.4 | -58.0 -72.4 225 38 20 1.5 0.8
36000 -56.4 -69.5 235 35 18 0.7 0.4 | -57.2 -71.0 225 39 20 1.5 0.8
34000 -56.0 -68.8 235 38 19 2.7 1.5 | -55.8 -68.4 220 40 21 6.1 3.4
32000 -53.0 -63.4 235 41 21 4.5 2.5 | -52.3 -62.1 210 37 19 5.8 3.2
30000 -49.8 -57.6 230 42 22 9.5 5.2 | -48.5 -55.3 205 35 18 9.1 5.0
29000 -47.0 -52.6 230 41 21 9.3 5.1 | -45.8 -50.4 210 33 17 9.0 5.0
28000 -44.3 -47.7 230 40 21 9.3 5.1 | -43.1 -45.6 215 31 16 9.0 5.0
27000 -41.5 -42.7 230 39 20 9.3 5.1 | -40.4 -40.7 220 29 15 8.9 4.9
26000 -38.7 -37.7 230 37 19 9.3 5.1 | -37.7 -35.9 220 28 15 8.7 4.8
25000 -36.0 -32.8 230 34 18 9.3 5.1 | -35.1 -31.2 225 28 14 8.8 4.8
24000 -33.2 -27.8 235 32 16 9.2 5.1 | -32.5 -26.5 230 27 14 8.7 4.8
23000 -30.5 -22.9 235 31 16 8.8 4.8 | -30.0 -22.0 230 26 13 8.6 4.7
22000 -27.9 -18.2 235 30 15 8.8 4.8 | -27.4 -17.3 225 25 13 8.6 4.7
21000 -25.3 -13.5 240 29 15 8.2 4.5 | -24.9 -12.8 225 23 12 7.9 4.4
20000 -23.0 -9.4 245 30 16 7.9 4.3 | -22.1 -7.8 220 22 11 7.6 4.2
19500 -21.8 -7.2 245 31 16 7.9 4.3 | -20.9 -5.6 220 21 11 7.6 4.2
19000 -20.1 -4.2 250 32 16 7.9 4.3 | -19.8 -3.6 215 21 11 7.6 4.2
18500 -18.9 -2.0 250 33 17 8.2 4.5 | -18.7 -1.7 215 21 11 7.7 4.2
18000 -17.7 0.1 250 34 17 8.2 4.5 | -17.6 0.3 210 21 11 7.7 4.2
17500 -16.5 2.3 250 35 18 7.7 4.2 | -16.4 2.5 210 22 11 7.5 4.1
17000 -15.4 4.3 245 34 17 7.2 3.9 | -15.4 4.3 210 22 11 7.3 4.0
16500 -14.4 6.1 240 33 17 7.1 3.9 | -14.3 6.3 210 22 11 7.3 4.0
16000 -13.4 7.9 235 32 16 5.9 3.2 | -13.2 8.2 215 22 11 7.5 4.1
15500 -12.5 9.5 230 30 15 6.3 3.4 | -12.1 10.2 215 22 11 7.5 4.1
15000 -11.9 10.6 225 27 14 2.7 1.5 | -11.0 12.2 220 21 11 7.6 4.2
14500 -11.5 11.3 220 24 12 2.7 1.5 | -9.9 14.2 220 21 11 7.8 4.3
14000 -11.1 12.0 210 21 11 1.4 0.8 | -8.9 16.0 220 20 10 3.2 1.8
13500 -11.0 12.2 200 18 9 1.0 0.5 | -8.7 16.3 215 18 9 2.0 1.1
13000 -10.8 12.6 180 16 8 1.3 0.7 | -8.4 16.9 205 16 8 -0.3 -0.2
12500 -10.6 12.9 160 15 8 1.5 0.8 | -8.7 16.3 190 15 8 -0.9 -0.5
12000 -10.4 13.3 150 15 8 3.1 1.7 | -8.7 16.3 180 15 8 1.3 0.7
11750 -10.1 13.8 150 14 7 4.4 2.4 | -8.5 16.7 175 15 8 3.0 1.6
11500 -9.8 14.4 145 13 7 4.0 2.2 | -8.3 17.1 170 15 8 2.5 1.4
11250 -9.5 14.9 140 12 6 4.5 2.5 | -8.1 17.4 160 15 8 0.7 0.4
11000 -9.2 15.4 140 12 6 2.2 1.2 | -8.1 17.4 160 15 8 0.7 0.4
10750 -9.1 15.6 145 12 6 0.3 0.2 | -8.0 17.6 160 15 8 2.3 1.3
10500 -9.1 15.6 150 13 6 0.5 0.3 | -7.9 17.8 165 15 8 1.3 0.7
10250 -9.0 15.8 155 13 7 1.6 0.9 | -7.7 18.1 165 15 8 3.7 2.1
10000 -8.8 16.2 160 13 7 2.6 1.4 | -7.4 18.7 170 15 8 3.7 2.0
9750 -8.7 16.3 165 14 7 2.0 1.1 | -7.3 18.9 175 16 8 1.4 0.7
9500 -8.6 16.5 170 15 8 2.0 1.1 | -7.1 19.2 175 17 9 1.9 1.0
9250 -8.4 16.9 170 16 8 2.6 1.4 | -7.0 19.4 180 17 9 2.1 1.2
9000 -8.1 17.4 170 15 8 6.0 3.3 | -6.7 19.9 180 17 9 6.5 3.6
8750 -7.6 18.3 170 15 8 7.8 4.3 | -6.1 21.0 180 16 8 9.2 5.1
8500 -7.0 19.4 170 14 7 7.5 4.1 | -5.5 22.1 180 16 8 8.7 4.8
8250 -6.5 20.3 170 13 7 7.8 4.3 | -4.9 23.2 180 15 8 8.2 4.5
8000 -5.8 21.6 165 12 6 10.7 5.9 | -4.2 24.4 180 14 7 12.6 6.9
7750 -4.8 23.4 165 10 5 16.0 8.8 | -2.9 26.8 175 12 6 22.0 12.1
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
03/15/2024 at 1500 MDT | 03/15/2024 at 1800 MDT
|
CAPE... +10.4 LI... +1.2 | CAPE... +1.0 LI... +1.3
CINH... 0.0 K Index... +17.9 | CINH... 0.0 K Index... +19.6
|
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 -56.4 -69.5 260 28 15 1.7 1.0 | -56.8 -70.2 255 32 16 1.9 1.0
45000 -53.7 -64.7 255 34 18 0.8 0.4 | -53.8 -64.8 250 33 17 0.9 0.5
40000 -57.0 -70.6 240 40 20 -2.3 -1.3 | -56.5 -69.7 250 34 18 -1.8 -1.0
38000 -57.6 -71.7 235 42 21 1.1 0.6 | -56.8 -70.2 240 35 18 1.5 0.8
36000 -56.9 -70.4 225 43 22 1.1 0.6 | -55.9 -68.6 225 37 19 1.5 0.8
34000 -55.6 -68.1 215 45 23 6.7 3.7 | -54.4 -65.9 210 41 21 6.3 3.5
32000 -51.8 -61.2 205 41 21 6.3 3.5 | -50.8 -59.4 210 37 19 6.0 3.3
30000 -47.7 -53.9 200 39 20 9.0 4.9 | -47.1 -52.8 210 33 17 7.7 4.2
29000 -45.0 -49.0 200 36 19 9.0 4.9 | -44.8 -48.6 210 31 16 7.7 4.2
28000 -42.3 -44.1 200 34 18 9.0 4.9 | -42.5 -44.5 205 30 15 7.7 4.2
27000 -39.6 -39.3 205 32 16 8.8 4.8 | -40.2 -40.4 200 29 15 7.9 4.4
26000 -37.1 -34.8 205 29 15 8.6 4.7 | -37.7 -35.9 205 26 13 8.4 4.6
25000 -34.5 -30.1 210 27 14 8.6 4.7 | -35.2 -31.4 205 22 12 8.4 4.6
24000 -31.9 -25.4 210 24 12 8.5 4.7 | -32.7 -26.9 210 19 10 8.5 4.6
23000 -29.5 -21.1 215 22 11 8.2 4.5 | -30.1 -22.2 215 16 8 8.7 4.8
22000 -27.1 -16.8 220 19 10 8.2 4.5 | -27.5 -17.5 220 13 7 8.7 4.8
21000 -24.6 -12.3 230 17 9 7.9 4.4 | -24.9 -12.8 225 10 5 8.2 4.5
20000 -21.8 -7.2 235 14 7 7.8 4.3 | -22.0 -7.6 220 7 3 7.9 4.3
19500 -20.6 -5.1 235 13 7 7.8 4.3 | -20.9 -5.6 215 5 3 7.9 4.3
19000 -19.4 -2.9 240 12 6 7.9 4.3 | -19.7 -3.5 205 4 2 7.9 4.4
18500 -18.3 -0.9 245 12 6 7.3 4.0 | -18.6 -1.5 200 4 2 7.5 4.1
18000 -17.2 1.0 245 13 7 7.3 4.0 | -17.5 0.5 210 4 2 7.5 4.1
17500 -16.2 2.8 245 14 7 7.4 4.0 | -16.4 2.5 220 4 2 7.2 4.0
17000 -15.1 4.8 240 15 8 7.4 4.1 | -15.3 4.5 215 4 2 6.9 3.8
16500 -14.0 6.8 240 16 8 7.4 4.1 | -14.3 6.3 210 4 2 6.9 3.8
16000 -12.9 8.8 240 17 9 7.2 4.0 | -13.3 8.1 220 6 3 6.9 3.8
15500 -11.9 10.6 235 19 10 7.2 4.0 | -12.3 9.9 230 8 4 6.9 3.8
15000 -10.8 12.6 235 20 10 7.4 4.0 | -11.3 11.7 235 10 5 6.8 3.7
14500 -9.7 14.5 235 21 11 7.4 4.1 | -10.3 13.5 240 12 6 6.8 3.7
14000 -8.7 16.3 230 21 11 5.8 3.2 | -9.3 15.3 245 13 7 7.4 4.1
13500 -7.9 17.8 230 19 10 5.4 3.3 | -8.1 17.4 240 15 8 7.6 4.2
13000 -7.1 19.2 230 16 8 4.5 2.5 | -7.0 19.4 240 16 8 7.4 4.1
12500 -6.5 20.3 220 16 8 4.5 2.5 | -6.0 21.2 235 17 9 6.3 3.5
12000 -5.8 21.6 215 15 8 2.7 1.5 | -5.1 22.8 235 16 8 4.8 2.7
11750 -5.7 21.7 210 15 8 0.5 0.3 | -4.8 23.4 230 16 8 3.3 1.8
11500 -5.7 21.7 205 15 8 0.9 0.5 | -4.5 23.9 230 16 8 3.8 2.1
11250 -5.7 21.7 205 16 8 -0.9 -0.5 | -4.2 24.4 225 16 8 5.2 2.8
11000 -5.8 21.6 200 16 8 -1.6 -0.9 | -3.9 25.0 220 16 8 3.2 1.7
10750 -5.9 21.4 200 17 9 -1.2 -0.6 | -3.8 25.2 220 16 8 0.8 0.4
10500 -6.0 21.2 195 18 9 -1.7 -0.9 | -3.7 25.3 215 16 8 1.4 0.8
10250 -6.1 21.0 195 19 10 -0.1 -0.0 | -3.6 25.5 210 17 9 1.3 0.7
10000 -6.0 21.2 195 21 11 2.2 1.2 | -3.5 25.7 210 17 9 1.2 0.6
9750 -5.8 21.6 190 22 11 2.1 1.2 | -3.4 25.9 205 18 9 0.9 0.5
9500 -5.7 21.7 190 23 12 2.5 1.4 | -3.3 26.1 205 18 9 1.2 0.7
9250 -5.5 22.1 190 24 12 1.1 0.6 | -3.3 26.1 205 19 10 0.3 0.1
9000 -5.4 22.3 190 24 12 4.2 2.3 | -3.3 26.1 200 19 10 1.2 0.7
8750 -4.9 23.2 190 24 12 8.0 4.4 | -3.1 26.4 200 19 10 2.9 1.6
8500 -4.4 24.1 185 24 12 7.0 3.9 | -3.0 26.6 195 20 10 2.2 1.2
8250 -3.9 25.0 185 24 12 7.5 4.1 | -2.8 27.0 195 20 10 3.4 1.9
8000 -3.2 26.2 185 23 12 12.2 6.7 | -2.4 27.7 190 19 10 8.1 4.5
7750 -2.0 28.4 180 19 10 19.6 10.7 | -1.7 28.9 185 15 8 13.0 7.1
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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