Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
836
UXUS97 KPUB 051228
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0628 MDT Sunday, May 5, 2024
This forecast is for the Air Force Academy for Sunday, May 5, 2024:
If the trigger temperature of 57.1 F/14.0 C is reached...then
Thermal Soaring Index....................... Good
Maximum rate of lift........................ 1240 ft/min (6.3 m/s)
Maximum height of thermals.................. 22661 ft MSL (15029 ft AGL)
Forecast maximum temperature................... 72.0 F/22.7 C
Time of trigger temperature.................... 1115 MDT
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast thin middle
Surface winds during soaring window............ Between 20 mph and 30 mph
Height of the -3 thermal index................. 18319 ft MSL (10687 ft AGL)
Thermal soaring outlook for Monday 05/06....... Good
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 05:55:37 / 19:56:14 MDT
Total possible sunshine........... 14 hr 0 min 37 sec (840 min 37 sec)
Altitude of sun at 12:55:55 MDT... 67.56 degrees
Upper air data from numerical model forecast valid on 05/05/2024 at 0600 MDT
Freezing level.................. 12448 ft MSL (4816 ft AGL)
Convective condensation level... 14545 ft MSL (6913 ft AGL)
Lifted condensation level....... 17586 ft MSL (9954 ft AGL)
Lifted index.................... -4.0
K index......................... +5.8
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 -56.8 -70.2 240 33 17 0.1 0.0 M M M M M
45000 -56.8 -70.2 240 36 18 -3.1 -1.7 M M M M M
40000 -62.0 -79.6 265 31 16 -2.9 -1.6 M M M M M
38000 -58.6 -73.5 270 33 17 8.7 4.8 M M M M M
36000 -53.3 -63.9 275 36 18 8.7 4.8 M M M M M
34000 -48.1 -54.6 275 36 18 8.6 4.7 M M M M M
32000 -43.0 -45.4 270 31 16 8.6 4.7 M M M M M
30000 -38.2 -36.8 265 27 14 6.7 3.7 30.8 87.5 6.7 M M
29000 -36.2 -33.2 260 26 14 6.7 3.7 29.6 85.3 5.8 M M
28000 -34.2 -29.6 250 26 13 6.7 3.7 28.5 83.4 5.0 M M
27000 -32.2 -26.0 245 25 13 6.5 3.6 27.5 81.5 4.2 M M
26000 -30.2 -22.4 240 25 13 6.5 3.6 26.2 79.1 3.2 M M
25000 -28.3 -18.9 240 24 13 6.5 3.6 25.0 77.0 2.3 M M
24000 -25.8 -14.4 235 23 12 6.8 3.8 23.6 74.5 1.2 M M
23000 -23.8 -10.8 230 22 11 6.8 3.7 22.5 72.5 0.2 M M
22000 -21.8 -7.2 225 20 10 6.9 3.8 21.5 70.7 -0.6 1371 7.0
21000 -19.6 -3.3 220 19 10 8.1 4.5 20.7 69.2 -1.4 1276 6.5
20000 -17.2 1.0 220 19 10 8.1 4.4 20.0 68.1 -2.0 1174 6.0
19500 -16.0 3.2 220 18 10 8.1 4.4 19.8 67.6 -2.2 1123 5.7
19000 -14.8 5.4 220 18 9 8.3 4.6 19.5 67.1 -2.4 1072 5.4
18500 -13.7 7.3 220 19 10 6.1 3.4 19.1 66.4 -2.8 1025 5.2
18000 -12.7 9.1 225 19 10 6.3 3.4 18.5 65.3 -3.4 982 5.0
17500 -11.8 10.8 230 20 10 5.9 3.2 18.0 64.3 -3.9 939 4.8
17000 -11.0 12.2 235 21 11 5.5 3.0 17.2 63.0 -4.6 901 4.6
16500 -10.2 13.6 240 22 12 5.5 3.0 16.5 61.8 -5.3 863 4.4
16000 -9.3 15.3 240 24 12 7.3 4.0 16.0 60.8 -5.9 820 4.2
15500 -8.3 17.1 245 26 13 7.1 3.9 15.6 60.0 -6.4 774 3.9
15000 -7.1 19.2 245 27 14 8.5 4.7 15.2 59.4 -6.7 726 3.7
14500 -5.9 21.4 245 28 14 8.7 4.7 15.1 59.1 -7.0 673 3.4
14000 -4.6 23.7 245 29 15 9.1 5.0 14.9 58.8 -7.2 620 3.2
13500 -3.2 26.2 245 28 14 9.6 5.2 14.8 58.7 -7.4 564 2.9
13000 -1.9 28.6 245 27 14 11.9 6.5 14.8 58.6 -7.5 508 2.6
12500 -0.3 31.5 245 26 14 7.8 4.3 15.0 58.9 -7.4 446 2.3
12000 1.0 33.8 240 25 13 8.4 4.6 14.8 58.6 -7.6 394 2.0
11750 1.6 34.9 240 24 12 8.2 4.5 14.7 58.4 -7.8 368 1.9
11500 2.2 36.0 240 24 12 8.0 4.4 14.5 58.2 -7.9 343 1.7
11250 2.7 36.9 235 24 12 7.9 4.4 14.4 57.9 -8.1 319 1.6
11000 3.3 37.9 235 24 12 7.9 4.4 14.2 57.6 -8.3 295 1.5
10750 3.8 38.8 235 23 12 7.8 4.3 14.1 57.4 -8.5 270 1.4
10500 4.4 39.9 230 23 12 7.8 4.3 14.0 57.1 -8.7 246 1.3
10250 5.0 41.0 230 22 11 8.3 4.5 13.8 56.9 -8.9 222 1.1
10000 5.6 42.1 230 22 11 8.1 4.4 13.7 56.7 -9.1 196 1.0
9750 6.1 43.0 230 22 11 7.5 4.1 13.5 56.4 -9.3 172 0.9
9500 6.7 44.1 230 21 11 7.2 4.0 13.4 56.1 -9.5 149 0.8
9250 7.2 45.0 230 21 11 8.2 4.5 13.2 55.8 -9.7 125 0.6
9000 7.8 46.0 230 21 11 5.6 3.1 13.1 55.5 -9.9 100 0.5
8750 8.0 46.4 230 20 10 1.4 0.8 12.5 54.5 -10.4 87 0.4
8500 8.2 46.8 230 19 10 4.1 2.3 11.9 53.5 -11.0 75 0.4
8250 8.3 46.9 225 18 9 -4.4 -2.4 11.4 52.5 -11.6 63 0.3
8000 4.9 40.8 225 12 6 -33.7 -18.5 6.4 43.6 -16.6 150 0.8
7750 2.6 36.7 230 6 3 -25.9 -14.2 3.4 38.1 -19.6 212 1.1
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 * * * * * *
05/05/2024 at 0900 MDT | 05/05/2024 at 1200 MDT
|
CAPE... +6.1 LI... +0.4 | CAPE... +100.5 LI... -1.1
CINH... -13.9 K Index... -2.3 | CINH... -8.2 K Index... +8.6
|
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 -57.3 -71.1 235 32 16 -0.5 -0.3 | -58.1 -72.6 240 33 17 -1.2 -0.6
45000 -58.1 -72.6 235 33 17 -1.2 -0.7 | -59.8 -75.6 250 36 19 -0.4 -0.2
40000 -60.1 -76.2 250 40 21 -1.0 -0.6 | -60.5 -76.9 255 59 30 -0.5 -0.3
38000 -57.4 -71.3 255 42 22 6.3 3.5 | -57.0 -70.6 255 59 30 7.5 4.1
36000 -53.6 -64.5 255 43 22 6.3 3.5 | -52.5 -62.5 255 56 29 7.5 4.1
34000 -49.2 -56.6 255 44 22 8.9 4.9 | -47.9 -54.2 255 53 27 8.1 4.5
32000 -43.9 -47.0 250 42 22 8.9 4.9 | -43.0 -45.4 255 51 26 8.1 4.5
30000 -38.6 -37.5 245 41 21 9.0 4.9 | -38.0 -36.4 250 48 25 8.5 4.7
29000 -35.9 -32.6 245 40 21 9.0 4.9 | -35.5 -31.9 245 46 24 8.5 4.7
28000 -33.2 -27.8 245 39 20 9.0 5.0 | -32.9 -27.2 245 45 23 8.5 4.7
27000 -30.7 -23.3 245 38 20 5.8 3.2 | -30.5 -22.9 240 43 22 7.1 3.9
26000 -28.9 -20.0 240 36 18 5.8 3.2 | -28.3 -18.9 240 41 21 7.2 4.0
25000 -27.2 -17.0 240 34 17 5.8 3.2 | -26.2 -15.2 240 39 20 7.2 4.0
24000 -25.4 -13.7 240 31 16 6.6 3.6 | -23.6 -10.5 235 36 19 6.8 3.7
23000 -22.7 -8.9 235 29 15 7.3 4.0 | -21.5 -6.7 235 34 18 6.8 3.7
22000 -20.4 -4.7 235 26 14 7.3 4.0 | -19.5 -3.1 230 32 16 6.8 3.7
21000 -18.3 -0.9 230 24 12 6.6 3.6 | -17.6 0.3 230 31 16 5.8 3.2
20000 -16.3 2.7 230 21 11 6.6 3.6 | -15.9 3.4 230 31 16 5.9 3.2
19500 -15.3 4.5 230 19 10 6.6 3.6 | -15.0 5.0 230 32 16 5.9 3.2
19000 -14.3 6.3 230 17 9 6.6 3.6 | -14.1 6.6 230 32 16 5.8 3.2
18500 -13.4 7.9 230 17 9 6.5 3.6 | -13.2 8.2 230 32 16 6.5 3.6
18000 -12.4 9.7 230 17 9 6.6 3.6 | -12.2 10.0 230 32 16 6.5 3.6
17500 -11.4 11.5 235 17 9 7.1 3.9 | -11.2 11.8 230 32 16 7.5 4.1
17000 -10.3 13.5 235 19 10 7.5 4.1 | -9.9 14.2 230 33 17 8.4 4.6
16500 -9.2 15.4 235 21 11 7.6 4.1 | -8.6 16.5 230 34 18 8.4 4.6
16000 -8.1 17.4 235 23 12 7.5 4.1 | -7.4 18.7 230 35 18 7.6 4.1
15500 -7.0 19.4 235 26 13 7.6 4.2 | -6.2 20.8 225 35 18 7.7 4.2
15000 -5.9 21.4 235 28 15 7.1 3.9 | -5.1 22.8 225 36 18 7.0 3.8
14500 -4.9 23.2 235 29 15 7.1 3.9 | -4.0 24.8 225 37 19 7.0 3.8
14000 -3.8 25.2 235 30 16 7.8 4.3 | -3.0 26.6 225 38 19 7.4 4.0
13500 -2.7 27.1 235 29 15 8.3 4.5 | -1.9 28.6 220 36 19 7.8 4.3
13000 -1.5 29.3 230 28 14 11.2 6.1 | -0.8 30.6 220 35 18 8.5 4.7
12500 -0.0 32.0 230 26 13 6.5 3.6 | 0.2 32.4 215 33 17 6.6 3.6
12000 1.1 34.0 220 22 11 7.9 4.4 | 1.2 34.2 210 28 14 6.8 3.7
11750 1.7 35.1 220 22 11 9.4 5.2 | 1.7 35.1 210 27 14 6.4 3.5
11500 2.4 36.3 220 21 11 8.4 4.6 | 2.1 35.8 205 26 14 7.1 3.9
11250 3.0 37.4 215 21 11 7.6 4.2 | 2.7 36.9 205 25 13 7.8 4.3
11000 3.5 38.3 215 20 10 7.6 4.1 | 3.2 37.8 200 24 12 7.5 4.1
10750 4.0 39.2 215 20 10 7.0 3.8 | 3.7 38.7 200 23 12 7.2 3.9
10500 4.5 40.1 210 20 10 7.0 3.8 | 4.2 39.6 195 23 12 7.4 4.1
10250 5.1 41.2 210 21 11 8.1 4.5 | 4.8 40.6 195 23 12 9.6 5.3
10000 5.6 42.1 210 21 11 7.5 4.1 | 5.5 41.9 195 22 11 9.8 5.4
9750 6.1 43.0 215 21 11 5.8 3.2 | 6.2 43.2 195 21 11 8.4 4.6
9500 6.4 43.5 215 21 11 5.5 3.0 | 6.7 44.1 190 21 11 7.4 4.1
9250 6.8 44.2 215 21 11 6.5 3.5 | 7.3 45.1 190 20 10 10.7 5.9
9000 7.2 45.0 215 22 11 5.8 3.2 | 8.2 46.8 190 20 10 12.7 6.9
8750 7.6 45.7 215 20 10 4.2 2.3 | 9.0 48.2 185 19 10 10.1 5.5
8500 7.9 46.2 215 19 10 4.1 2.2 | 9.8 49.6 185 19 10 10.8 5.9
8250 8.2 46.8 210 17 9 5.2 2.8 | 10.5 50.9 180 19 10 8.4 4.6
8000 8.7 47.7 210 15 8 11.3 6.2 | 11.3 52.3 180 18 9 15.7 8.6
7750 9.8 49.6 205 13 7 17.7 9.7 | 13.1 55.6 175 17 9 34.9 19.1
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
05/05/2024 at 1500 MDT | 05/05/2024 at 1800 MDT
|
CAPE... +134.4 LI... +0.2 | CAPE... +73.7 LI... +0.9
CINH... -19.2 K Index... +11.9 | CINH... -27.5 K Index... +20.0
|
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 -58.4 -73.1 235 38 19 -1.4 -0.8 | -58.6 -73.5 235 40 21 -3.6 -2.0
45000 -60.5 -76.9 240 45 23 -0.2 -0.1 | -63.6 -82.5 240 52 27 2.6 1.4
40000 -60.9 -77.6 250 69 36 -0.5 -0.3 | -60.5 -76.9 245 65 33 1.8 1.0
38000 -57.2 -71.0 250 69 35 7.9 4.3 | -56.9 -70.4 245 67 34 7.1 3.9
36000 -52.5 -62.5 250 66 34 7.9 4.3 | -52.6 -62.7 245 68 35 7.1 3.9
34000 -47.7 -53.9 245 61 32 8.1 4.5 | -47.9 -54.2 240 67 35 8.8 4.8
32000 -42.8 -45.0 245 55 28 8.1 4.5 | -42.6 -44.7 240 62 32 8.8 4.8
30000 -37.8 -36.0 245 50 26 8.7 4.8 | -37.4 -35.3 240 59 30 8.6 4.7
29000 -35.2 -31.4 240 48 25 8.7 4.8 | -34.9 -30.8 240 57 29 8.6 4.7
28000 -32.6 -26.7 240 47 24 8.7 4.8 | -32.3 -26.1 240 56 29 8.6 4.7
27000 -30.0 -22.0 240 46 24 7.7 4.2 | -29.8 -21.6 240 55 28 7.4 4.0
26000 -27.7 -17.9 240 47 24 7.8 4.3 | -27.6 -17.7 240 54 28 7.5 4.1
25000 -25.4 -13.7 240 48 25 7.8 4.3 | -25.3 -13.5 240 53 28 7.5 4.1
24000 -22.4 -8.3 240 47 24 8.7 4.8 | -23.1 -9.6 240 53 27 7.7 4.2
23000 -19.8 -3.6 235 40 21 8.6 4.7 | -20.7 -5.3 240 51 26 7.8 4.3
22000 -17.2 1.0 230 34 17 8.6 4.7 | -17.8 -0.0 240 49 25 7.9 4.3
21000 -15.0 5.0 230 31 16 5.9 3.2 | -15.5 4.1 240 45 23 8.2 4.5
20000 -13.2 8.2 235 34 17 6.0 3.3 | -13.0 8.6 235 36 18 8.2 4.5
19500 -12.3 9.9 240 36 18 6.0 3.3 | -11.8 10.8 235 31 16 8.2 4.5
19000 -11.4 11.5 245 37 19 6.3 3.4 | -10.6 12.9 230 27 14 8.7 4.8
18500 -10.6 12.9 245 40 21 3.8 2.1 | -9.7 14.5 230 27 14 3.7 2.0
18000 -10.0 14.0 240 44 23 4.0 2.2 | -9.1 15.6 230 32 16 3.9 2.2
17500 -9.4 15.1 240 49 25 4.3 2.4 | -8.6 16.5 230 37 19 4.0 2.2
17000 -8.7 16.3 235 49 25 4.8 2.6 | -8.0 17.6 225 39 20 4.1 2.3
16500 -8.0 17.6 230 49 25 4.7 2.6 | -7.4 18.7 220 41 21 3.9 2.1
16000 -7.2 19.0 230 47 24 6.1 3.4 | -6.6 20.1 215 42 21 7.8 4.3
15500 -6.3 20.7 225 44 23 6.1 3.4 | -5.5 22.1 210 40 21 7.4 4.1
15000 -5.5 22.1 220 42 21 7.2 4.0 | -4.3 24.3 205 39 20 8.8 4.8
14500 -4.4 24.1 215 39 20 7.6 4.1 | -3.0 26.6 205 39 20 9.2 5.0
14000 -3.4 25.9 210 37 19 8.2 4.5 | -1.6 29.1 200 39 20 8.8 4.8
13500 -2.1 28.2 205 36 18 8.8 4.8 | -0.4 31.3 195 38 19 8.3 4.6
13000 -0.9 30.4 205 34 18 10.3 5.6 | 0.8 33.4 190 37 19 10.2 5.6
12500 0.4 32.7 200 34 17 6.4 3.5 | 2.1 35.8 190 36 19 6.3 3.4
12000 1.4 34.5 195 33 17 7.3 4.0 | 3.1 37.6 185 35 18 7.3 4.0
11750 2.0 35.6 195 32 17 8.5 4.7 | 3.6 38.5 180 34 18 9.2 5.0
11500 2.6 36.7 195 32 16 8.3 4.5 | 4.3 39.7 180 34 17 9.2 5.0
11250 3.2 37.8 190 31 16 7.8 4.3 | 5.0 41.0 180 33 17 8.3 4.6
11000 3.8 38.8 190 31 16 7.7 4.2 | 5.6 42.1 180 33 17 8.6 4.7
10750 4.3 39.7 185 30 15 6.4 3.5 | 6.3 43.3 175 32 16 9.1 5.0
10500 4.7 40.5 180 29 15 6.8 3.7 | 6.9 44.4 175 31 16 9.6 5.3
10250 5.3 41.5 180 28 14 10.2 5.6 | 7.7 45.9 175 31 16 9.9 5.4
10000 6.1 43.0 175 27 14 11.2 6.1 | 8.4 47.1 175 31 16 10.0 5.5
9750 6.9 44.4 175 27 14 9.7 5.3 | 9.2 48.6 175 30 16 9.9 5.4
9500 7.6 45.7 175 27 14 8.9 4.9 | 9.9 49.8 175 30 15 9.7 5.3
9250 8.3 46.9 175 26 13 10.6 5.8 | 10.6 51.1 175 30 15 10.4 5.7
9000 9.1 48.4 170 26 13 12.0 6.6 | 11.5 52.7 175 29 15 11.0 6.0
8750 10.0 50.0 170 26 13 10.6 5.8 | 12.2 54.0 170 29 15 9.9 5.4
8500 10.8 51.4 170 26 13 11.1 6.1 | 12.9 55.2 170 28 15 9.5 5.2
8250 11.6 52.9 170 25 13 8.3 4.6 | 13.7 56.7 170 28 14 9.5 5.2
8000 12.2 54.0 170 25 13 14.5 7.9 | 14.4 57.9 170 27 14 11.7 6.4
7750 14.0 57.2 170 22 12 34.2 18.8 | 15.4 59.7 170 23 12 16.5 9.1
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.
042613