947
UXUS97 KPUB 071209
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO, COLORADO
0608 MDT THURSDAY, AUGUST 7, 2025
THIS FORECAST IS FOR THURSDAY, AUGUST 7, 2025:
IF THE TRIGGER TEMPERATURE OF 79.4 F/26.3 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1574 FT/MIN (8.0 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 25487 FT MSL (17863 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 95.0 F/35.5 C
TIME OF TRIGGER TEMPERATURE.................... 0845 MDT
TIME OF OVERDEVELOPMENT........................ NONE
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... BROKEN/OVERCAST THIN MIDDLE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 22804 FT MSL (15180 FT AGL)
THERMAL SOARING OUTLOOK FOR FRIDAY 08/08....... EXCELLENT
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 06:06:05 / 20:03:56 MDT
TOTAL POSSIBLE SUNSHINE........... 13 HR 57 MIN 51 SEC (837 MIN 51 SEC)
ALTITUDE OF SUN AT 13:05:01 MDT... 67.18 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 08/07/2025 AT 0600 MDT
FREEZING LEVEL.................. 16796 FT MSL (9172 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 19075 FT MSL (11451 FT AGL)
LIFTED CONDENSATION LEVEL....... 21770 FT MSL (14147 FT AGL)
LIFTED INDEX.................... -4.6
K INDEX......................... +18.1
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 -65.8 -86.4 260 22 12 0.4 0.2 M M M M M
45000 -62.8 -81.0 260 36 19 5.3 2.9 M M M M M
40000 -53.6 -64.5 265 47 24 8.1 4.5 M M M M M
38000 -48.7 -55.7 270 48 25 8.1 4.4 M M M M M
36000 -43.9 -47.0 270 48 25 8.0 4.4 M M M M M
34000 -39.1 -38.4 270 43 22 7.9 4.4 M M M M M
32000 -34.3 -29.7 265 39 20 8.0 4.4 M M M M M
30000 -30.0 -22.0 270 33 17 7.2 4.0 38.4 101.1 2.6 M M
29000 -27.8 -18.0 270 30 16 7.2 4.0 37.5 99.5 1.9 M M
28000 -25.6 -14.1 275 28 14 8.2 4.5 36.7 98.1 1.3 M M
27000 -23.1 -9.6 275 26 13 8.1 4.4 36.0 96.8 0.8 M M
26000 -20.7 -5.3 275 24 13 8.1 4.4 35.4 95.7 0.3 M M
25000 -17.9 -0.2 280 22 11 5.7 3.1 34.5 94.1 -0.5 1717 8.7
24000 -16.1 3.0 280 18 9 6.0 3.3 33.1 91.5 -1.7 1634 8.3
23000 -14.3 6.3 280 14 7 6.0 3.3 31.8 89.2 -2.9 1551 7.9
22000 -12.4 9.7 280 11 6 7.8 4.3 30.7 87.2 -3.9 1464 7.4
21000 -10.2 13.6 285 10 5 7.6 4.2 29.9 85.8 -4.7 1367 6.9
20000 -7.9 17.8 285 9 4 7.6 4.2 29.2 84.5 -5.4 1270 6.5
19500 -6.8 19.8 290 8 4 8.2 4.5 28.9 84.0 -5.7 1221 6.2
19000 -5.5 22.1 290 9 5 8.3 4.6 28.6 83.5 -6.0 1169 5.9
18500 -4.3 24.3 290 10 5 8.4 4.6 28.4 83.1 -6.2 1118 5.7
18000 -3.1 26.4 290 11 6 8.9 4.9 28.2 82.8 -6.5 1065 5.4
17500 -1.8 28.8 285 13 6 8.9 4.9 28.0 82.5 -6.7 1011 5.1
17000 -0.5 31.1 285 14 7 8.6 4.7 27.9 82.2 -6.9 958 4.9
16500 0.8 33.4 285 15 8 8.6 4.7 27.7 81.8 -7.2 906 4.6
16000 2.0 35.6 285 16 8 8.8 4.8 27.5 81.5 -7.4 854 4.3
15500 3.3 37.9 285 17 9 9.3 5.1 27.4 81.3 -7.6 800 4.1
15000 4.6 40.3 285 18 9 9.3 5.1 27.3 81.1 -7.8 745 3.8
14500 6.0 42.8 285 18 9 9.5 5.2 27.2 81.0 -7.9 689 3.5
14000 7.4 45.3 285 18 9 9.6 5.3 27.2 81.0 -8.0 633 3.2
13500 8.8 47.8 280 19 10 8.9 4.9 27.1 80.8 -8.2 577 2.9
13000 10.1 50.2 280 19 10 9.4 5.2 27.0 80.6 -8.4 523 2.7
12500 11.6 52.9 280 19 10 10.7 5.8 27.1 80.8 -8.3 462 2.3
12000 13.2 55.8 280 18 9 10.8 5.9 27.2 81.0 -8.3 400 2.0
11750 14.0 57.2 280 18 9 9.4 5.2 27.3 81.1 -8.2 369 1.9
11500 14.6 58.3 280 18 9 8.7 4.8 27.2 80.9 -8.3 343 1.7
11250 15.3 59.5 280 18 9 9.6 5.3 27.2 80.9 -8.4 314 1.6
11000 16.0 60.8 280 18 9 9.5 5.2 27.1 80.8 -8.4 285 1.5
10750 16.7 62.1 280 18 9 9.0 4.9 27.1 80.8 -8.5 257 1.3
10500 17.4 63.3 280 18 9 11.3 6.2 27.1 80.8 -8.5 228 1.2
10250 18.3 64.9 280 18 9 10.5 5.8 27.3 81.1 -8.4 194 1.0
10000 19.0 66.2 280 18 9 7.8 4.3 27.1 80.9 -8.5 168 0.9
9750 19.6 67.3 280 18 9 8.0 4.4 27.0 80.7 -8.6 142 0.7
9500 20.2 68.4 275 18 9 9.9 5.4 26.9 80.5 -8.8 116 0.6
9250 21.0 69.8 275 17 9 8.3 4.5 27.0 80.6 -8.7 85 0.4
9000 21.4 70.5 275 17 9 4.3 2.4 26.6 80.0 -9.1 66 0.3
8750 21.7 71.1 270 17 9 5.1 2.8 26.3 79.3 -9.5 50 0.3
8500 22.0 71.6 270 17 9 2.5 1.4 25.9 78.5 -10.0 34 0.2
8250 21.9 71.4 265 19 10 -1.6 -0.9 25.1 77.2 -10.8 28 0.1
8000 21.7 71.1 265 20 10 -1.9 -1.0 24.2 75.6 -11.8 28 0.1
7750 20.9 69.6 265 20 10 -24.2 -13.3 22.8 73.1 -13.4 44 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 * * * * * *
08/07/2025 AT 0900 MDT | 08/07/2025 AT 1200 MDT
|
CAPE... +482.1 LI... -1.0 | CAPE... +135.3 LI... +0.1
CINH... -49.0 K INDEX... +22.4 | CINH... -7.0 K INDEX... +15.2
|
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 -65.9 -86.6 255 26 13 0.0 0.0 | -66.0 -86.8 260 30 16 -0.4 -0.2
45000 -63.2 -81.8 260 43 22 5.6 3.1 | -63.6 -82.5 265 46 24 5.9 3.2
40000 -53.7 -64.7 265 48 25 8.0 4.4 | -53.8 -64.8 265 48 25 7.8 4.3
38000 -48.9 -56.0 265 46 24 8.0 4.4 | -49.1 -56.4 265 47 24 7.8 4.3
36000 -44.1 -47.4 270 44 23 8.0 4.4 | -44.4 -47.9 260 46 24 7.9 4.3
34000 -39.3 -38.7 265 42 22 8.0 4.4 | -39.6 -39.3 260 42 22 7.9 4.3
32000 -34.4 -29.9 265 40 20 8.0 4.4 | -34.9 -30.8 260 38 20 8.0 4.4
30000 -30.0 -22.0 265 34 17 7.3 4.0 | -30.3 -22.5 260 33 17 7.6 4.2
29000 -27.8 -18.0 265 31 16 7.3 4.0 | -28.1 -18.6 260 31 16 7.6 4.2
28000 -25.6 -14.1 265 29 15 7.9 4.4 | -25.8 -14.4 260 29 15 7.7 4.2
27000 -23.2 -9.8 270 29 15 7.9 4.3 | -23.5 -10.3 265 28 15 7.7 4.2
26000 -20.8 -5.4 270 28 14 7.9 4.3 | -21.2 -6.2 265 28 14 7.7 4.2
25000 -18.5 -1.3 275 28 14 7.2 3.9 | -18.9 -2.0 270 27 14 7.4 4.1
24000 -16.0 3.2 270 22 12 6.7 3.7 | -16.2 2.8 270 25 13 7.2 4.0
23000 -14.0 6.8 270 18 9 6.8 3.7 | -14.0 6.8 265 23 12 7.2 4.0
22000 -12.1 10.2 270 15 7 6.8 3.7 | -11.9 10.6 260 21 11 7.2 4.0
21000 -10.1 13.8 275 12 6 6.9 3.8 | -9.7 14.5 255 17 9 7.2 4.0
20000 -8.1 17.4 280 9 5 7.0 3.8 | -7.6 18.3 245 14 7 7.2 4.0
19500 -7.1 19.2 285 8 4 8.3 4.5 | -6.5 20.3 245 13 7 8.3 4.6
19000 -5.8 21.6 295 9 5 8.5 4.7 | -5.2 22.6 250 13 7 8.5 4.7
18500 -4.6 23.7 300 10 5 8.7 4.8 | -3.9 25.0 260 13 7 8.5 4.7
18000 -3.3 26.1 300 11 6 9.2 5.1 | -2.7 27.1 265 15 8 8.3 4.5
17500 -1.9 28.6 300 12 6 9.2 5.1 | -1.6 29.1 270 16 8 8.4 4.6
17000 -0.5 31.1 300 14 7 8.8 4.8 | -0.4 31.3 275 18 9 9.1 5.0
16500 0.8 33.4 300 16 8 8.7 4.8 | 0.9 33.6 275 17 9 9.3 5.1
16000 2.1 35.8 295 18 9 8.8 4.8 | 2.3 36.1 275 17 9 9.5 5.2
15500 3.4 38.1 295 18 9 9.0 4.9 | 3.6 38.5 275 16 8 9.5 5.2
15000 4.7 40.5 295 18 9 9.0 4.9 | 5.0 41.0 275 15 8 9.5 5.2
14500 6.1 43.0 295 18 9 9.4 5.2 | 6.5 43.7 275 15 8 9.7 5.3
14000 7.5 45.5 290 18 9 9.4 5.2 | 7.9 46.2 275 15 8 9.7 5.3
13500 8.8 47.8 290 18 9 9.1 5.0 | 9.4 48.9 275 15 8 9.5 5.2
13000 10.2 50.4 290 17 9 9.5 5.2 | 10.8 51.4 275 14 7 10.0 5.5
12500 11.7 53.1 290 17 9 9.9 5.4 | 12.3 54.1 275 14 7 10.6 5.8
12000 13.1 55.6 290 17 9 9.7 5.3 | 13.9 57.0 280 14 7 10.7 5.9
11750 13.8 56.8 290 17 9 9.0 5.0 | 14.7 58.5 280 14 7 9.4 5.2
11500 14.4 57.9 290 17 9 8.7 4.8 | 15.3 59.5 280 14 7 9.1 5.0
11250 15.1 59.2 290 17 9 9.2 5.0 | 16.1 61.0 280 14 7 10.1 5.5
11000 15.8 60.4 290 17 9 9.1 5.0 | 16.8 62.2 280 14 7 10.0 5.5
10750 16.5 61.7 290 17 9 8.9 4.9 | 17.6 63.7 280 14 7 9.5 5.2
10500 17.2 63.0 290 17 9 11.5 6.3 | 18.3 64.9 280 14 7 11.8 6.5
10250 18.1 64.6 290 17 9 10.5 5.8 | 19.3 66.7 280 13 7 11.0 6.0
10000 18.7 65.7 290 18 9 7.8 4.3 | 19.9 67.8 280 13 7 8.5 4.6
9750 19.3 66.7 290 18 9 8.1 4.4 | 20.6 69.1 280 13 7 8.2 4.5
9500 20.0 68.0 290 18 9 10.1 5.6 | 21.2 70.2 280 13 7 11.8 6.4
9250 20.8 69.4 285 18 10 9.7 5.3 | 22.2 72.0 280 13 7 12.2 6.7
9000 21.3 70.3 285 19 10 6.8 3.7 | 22.9 73.2 280 13 7 8.5 4.7
8750 21.8 71.2 285 19 10 7.3 4.0 | 23.6 74.5 280 13 6 9.1 5.0
8500 22.3 72.1 280 19 10 5.6 3.1 | 24.3 75.7 280 12 6 10.0 5.5
8250 22.6 72.7 280 18 9 4.6 2.5 | 25.2 77.4 280 12 6 11.5 6.3
8000 22.9 73.2 275 18 9 4.9 2.7 | 25.9 78.6 280 12 6 8.9 4.9
7750 23.2 73.8 270 15 8 8.0 4.4 | 26.7 80.1 280 11 6 14.6 8.0
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
08/07/2025 AT 1500 MDT | 08/07/2025 AT 1800 MDT
|
CAPE... +438.0 LI... -1.0 | CAPE... +510.4 LI... -0.8
CINH... -1.4 K INDEX... +26.5 | CINH... -16.2 K INDEX... +26.4
|
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 -65.5 -85.9 265 31 16 0.1 0.0 | -65.1 -85.2 265 32 16 -0.4 -0.2
45000 -62.8 -81.0 265 45 23 5.4 2.9 | -63.2 -81.8 265 46 24 5.0 2.7
40000 -53.7 -64.7 265 51 26 7.8 4.3 | -54.4 -65.9 260 49 25 8.5 4.7
38000 -49.0 -56.2 260 49 25 7.8 4.3 | -49.2 -56.6 260 47 24 8.5 4.7
36000 -44.3 -47.7 260 47 24 7.6 4.2 | -44.1 -47.4 260 44 23 7.9 4.3
34000 -39.9 -39.8 260 43 22 7.5 4.1 | -39.5 -39.1 260 42 22 7.6 4.2
32000 -35.4 -31.7 260 40 20 7.8 4.3 | -35.0 -31.0 260 40 21 8.0 4.4
30000 -30.7 -23.3 260 36 19 7.7 4.2 | -30.2 -22.4 265 39 20 7.9 4.4
29000 -28.4 -19.1 255 34 18 7.7 4.2 | -27.8 -18.0 265 38 20 7.9 4.4
28000 -26.1 -15.0 255 33 17 7.3 4.0 | -25.6 -14.1 265 37 19 6.2 3.4
27000 -23.9 -11.0 260 30 16 7.4 4.0 | -23.7 -10.7 265 34 17 6.4 3.5
26000 -21.7 -7.1 260 28 15 7.4 4.0 | -21.7 -7.1 265 30 16 6.5 3.5
25000 -19.5 -3.1 265 27 14 7.2 4.0 | -19.8 -3.6 270 27 14 7.3 4.0
24000 -16.9 1.6 265 25 13 7.3 4.0 | -16.9 1.6 270 24 13 8.0 4.4
23000 -14.8 5.4 265 25 13 7.4 4.1 | -14.6 5.7 270 22 11 8.2 4.5
22000 -12.5 9.5 265 23 12 8.6 4.7 | -12.2 10.0 275 20 10 9.0 5.0
21000 -10.1 13.8 270 21 11 8.6 4.7 | -9.6 14.7 275 18 9 9.0 5.0
20000 -7.6 18.3 270 18 9 8.7 4.8 | -7.0 19.4 275 16 8 9.1 5.0
19500 -6.4 20.5 270 17 9 9.6 5.2 | -5.7 21.7 275 15 8 9.2 5.0
19000 -4.9 23.2 270 16 8 9.7 5.3 | -4.3 24.3 275 15 8 9.2 5.1
18500 -3.5 25.7 270 16 8 9.7 5.3 | -2.9 26.8 275 14 7 9.2 5.1
18000 -2.0 28.4 270 15 8 9.9 5.4 | -1.4 29.5 275 14 7 9.8 5.4
17500 -0.5 31.1 270 15 8 9.9 5.4 | 0.0 32.0 275 14 7 9.7 5.3
17000 1.0 33.8 270 15 8 9.7 5.3 | 1.5 34.7 275 14 7 9.7 5.3
16500 2.4 36.3 270 14 7 9.6 5.3 | 2.9 37.2 270 13 7 9.7 5.3
16000 3.8 38.8 270 14 7 9.7 5.3 | 4.4 39.9 270 12 6 9.7 5.3
15500 5.3 41.5 270 14 7 9.8 5.4 | 5.8 42.4 270 12 6 9.5 5.2
15000 6.7 44.1 265 13 7 9.8 5.4 | 7.2 45.0 270 11 6 9.5 5.2
14500 8.2 46.8 265 13 7 9.7 5.3 | 8.7 47.7 265 11 5 9.8 5.4
14000 9.7 49.5 265 13 6 9.8 5.4 | 10.1 50.2 265 10 5 9.7 5.3
13500 11.1 52.0 265 12 6 9.7 5.3 | 11.6 52.9 260 9 5 9.7 5.3
13000 12.6 54.7 265 12 6 9.7 5.3 | 13.0 55.4 250 9 5 9.7 5.3
12500 14.1 57.4 265 11 6 10.2 5.6 | 14.5 58.1 250 9 5 10.1 5.5
12000 15.6 60.1 265 11 6 10.5 5.8 | 16.0 60.8 240 9 4 11.0 6.0
11750 16.4 61.5 260 11 6 9.8 5.4 | 16.8 62.2 240 9 4 8.3 4.5
11500 17.1 62.8 260 11 5 9.5 5.2 | 17.3 63.1 235 9 4 7.2 4.0
11250 17.8 64.0 260 11 5 10.1 5.6 | 18.0 64.4 235 9 4 10.0 5.5
11000 18.6 65.5 260 10 5 9.9 5.4 | 18.7 65.7 230 9 4 9.9 5.4
10750 19.3 66.7 260 10 5 10.3 5.6 | 19.5 67.1 225 9 5 10.5 5.7
10500 20.1 68.2 260 10 5 9.2 5.0 | 20.2 68.4 220 9 5 8.2 4.5
10250 20.7 69.3 260 10 5 9.2 5.0 | 20.7 69.3 220 9 5 7.9 4.3
10000 21.5 70.7 260 10 5 10.0 5.5 | 21.4 70.5 215 9 5 9.8 5.4
9750 22.2 72.0 260 9 5 10.4 5.7 | 22.1 71.8 210 10 5 9.6 5.3
9500 22.9 73.2 260 9 5 8.1 4.4 | 22.8 73.0 205 10 5 8.6 4.7
9250 23.5 74.3 260 9 5 8.6 4.7 | 23.4 74.1 205 10 5 8.7 4.8
9000 24.3 75.7 260 9 5 11.3 6.2 | 24.1 75.4 200 11 5 9.8 5.4
8750 25.1 77.2 260 9 4 10.8 5.9 | 24.8 76.6 195 11 6 9.6 5.3
8500 25.9 78.6 260 8 4 10.3 5.6 | 25.6 78.1 195 11 6 9.2 5.1
8250 26.7 80.1 255 8 4 10.4 5.7 | 26.2 79.2 190 11 6 8.7 4.8
8000 27.6 81.7 255 8 4 15.4 8.4 | 26.9 80.4 190 10 5 10.3 5.6
7750 28.9 84.0 255 7 4 20.8 11.4 | 27.7 81.9 190 9 5 12.3 6.7
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) 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 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.
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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