918  
UXUS97 KPUB 231316  
SRGPUB  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE PUEBLO, COLORADO  
0616 MST THURSDAY, NOVEMBER 23, 2017  
 
THIS FORECAST IS FOR THURSDAY, NOVEMBER 23, 2017:  
 
IF THE TRIGGER TEMPERATURE OF 57.9 F/14.4 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... GOOD  
MAXIMUM RATE OF LIFT........................ 549 FT/MIN (2.8 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 15339 FT MSL (7726 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 67.0 F/19.9 C  
TIME OF TRIGGER TEMPERATURE.................... 1030 MST  
TIME OF OVERDEVELOPMENT........................ NONE  
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... OVERCAST THIN HIGH  
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS  
HEIGHT OF THE -3 THERMAL INDEX................. 13102 FT MSL (5489 FT AGL)  
THERMAL SOARING OUTLOOK FOR FRIDAY 11/24....... GOOD  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
SUNRISE/SUNSET.................... 06:51:27 / 16:40:11 MST  
TOTAL POSSIBLE SUNSHINE........... 9 HR 48 MIN 44 SEC (588 MIN 44 SEC)  
ALTITUDE OF SUN AT 11:45:49 MST... 30.43 DEGREES  
 
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 11/23/2017 AT 0500 MST  
 
FREEZING LEVEL.................. 12982 FT MSL (5369 FT AGL)  
CONVECTIVE CONDENSATION LEVEL... 16359 FT MSL (8746 FT AGL)  
LIFTED CONDENSATION LEVEL....... 15905 FT MSL (8292 FT AGL)  
LIFTED INDEX.................... +1.9  
K INDEX......................... +8.6  
 
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 -68.4 -91.1 320 31 16 0.3 0.2 M M M M M  
45000 -66.6 -87.9 315 38 20 5.4 3.0 M M M M M  
40000 -58.5 -73.3 315 41 21 7.1 3.9 M M M M M  
38000 -53.7 -64.7 315 38 20 8.1 4.4 M M M M M  
36000 -48.2 -54.8 320 36 18 8.1 4.4 M M M M M  
34000 -43.4 -46.1 320 33 17 8.0 4.4 M M M M M  
32000 -38.6 -37.5 325 31 16 8.0 4.4 M M M M M  
30000 -34.0 -29.2 325 28 14 7.5 4.1 35.0 95.0 12.0 M M  
29000 -31.8 -25.2 325 26 13 7.5 4.1 34.1 93.4 11.5 M M  
28000 -29.5 -21.1 325 24 12 7.5 4.1 33.4 92.2 11.1 M M  
27000 -27.2 -17.0 325 23 12 7.8 4.3 32.6 90.6 10.5 M M  
26000 -24.9 -12.8 325 21 11 7.8 4.3 31.8 89.2 10.0 M M  
25000 -22.6 -8.7 325 20 10 7.8 4.3 31.2 88.1 9.6 M M  
24000 -20.2 -4.4 325 19 10 7.8 4.3 30.4 86.8 9.1 M M  
23000 -17.9 -0.2 330 18 9 7.8 4.3 29.7 85.4 8.5 M M  
22000 -15.0 5.0 330 18 9 7.5 4.1 28.9 84.0 8.0 M M  
21000 -13.1 8.4 330 18 9 6.2 3.4 27.7 81.8 7.0 M M  
20000 -11.3 11.7 330 18 9 6.3 3.4 26.5 79.7 6.0 M M  
19500 -10.3 13.5 330 18 9 6.4 3.5 25.9 78.7 5.5 M M  
19000 -9.5 14.9 330 17 9 5.2 2.9 25.3 77.5 5.0 M M  
18500 -8.7 16.3 330 17 9 5.2 2.9 24.5 76.1 4.3 M M  
18000 -7.9 17.8 330 17 9 5.2 2.9 23.8 74.8 3.6 M M  
17500 -7.2 19.0 335 16 8 5.2 2.9 23.0 73.4 2.9 M M  
17000 -6.4 20.5 335 16 8 5.3 2.9 22.2 72.0 2.3 M M  
16500 -5.7 21.7 335 15 8 5.5 3.0 21.5 70.7 1.6 M M  
16000 -4.9 23.2 335 15 8 5.5 3.0 20.8 69.5 0.9 M M  
15500 -4.1 24.6 335 14 7 5.5 3.0 20.1 68.2 0.2 M M  
15000 -3.3 26.1 335 13 7 5.5 3.0 19.4 66.9 -0.5 622 3.2  
14500 -2.5 27.5 335 13 7 5.6 3.1 18.7 65.7 -1.2 584 3.0  
14000 -1.7 28.9 335 12 6 5.8 3.2 18.1 64.5 -1.8 544 2.8  
13500 -0.9 30.4 335 11 6 5.8 3.2 17.5 63.4 -2.4 504 2.6  
13000 -0.1 31.8 330 10 5 5.4 2.9 16.8 62.2 -3.1 465 2.4  
12500 0.8 33.4 330 9 4 6.3 3.4 16.2 61.1 -3.8 426 2.2  
12000 1.6 34.9 325 8 4 6.0 3.3 15.6 60.1 -4.4 384 2.0  
11750 2.1 35.8 325 7 4 6.5 3.6 15.3 59.6 -4.7 364 1.8  
11500 2.5 36.5 320 6 3 4.8 2.7 15.0 59.1 -4.9 343 1.7  
11250 2.8 37.0 320 6 3 4.7 2.6 14.6 58.3 -5.4 327 1.7  
11000 3.2 37.8 320 6 3 6.4 3.5 14.3 57.7 -5.7 307 1.6  
10750 3.7 38.7 320 6 3 5.4 3.0 14.0 57.2 -6.0 287 1.5  
10500 4.1 39.4 320 6 3 7.6 4.2 13.7 56.7 -6.4 266 1.4  
10250 4.7 40.5 320 6 3 7.8 4.3 13.6 56.5 -6.5 240 1.2  
10000 5.2 41.4 325 6 3 5.9 3.2 13.3 56.0 -6.8 219 1.1  
9750 5.6 42.1 330 6 3 6.3 3.4 13.1 55.5 -7.1 198 1.0  
9500 6.1 43.0 335 6 3 6.6 3.6 12.8 55.1 -7.4 177 0.9  
9250 6.6 43.9 335 6 3 7.1 3.9 12.6 54.7 -7.6 155 0.8  
9000 7.1 44.8 335 6 3 6.1 3.3 12.4 54.3 -7.9 133 0.7  
8750 7.5 45.5 335 6 3 5.7 3.1 12.1 53.7 -8.2 113 0.6  
8500 7.9 46.2 335 6 3 5.2 2.9 11.8 53.2 -8.5 93 0.5  
8250 8.2 46.8 330 5 3 3.5 1.9 11.3 52.4 -8.9 76 0.4  
8000 8.3 46.9 320 5 2 -3.7 -2.0 10.7 51.2 -9.6 66 0.3  
7750 7.3 45.1 310 4 2 -29.4 -16.1 8.9 47.9 -11.4 90 0.5  
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 * * * * * *  
 
11/23/2017 AT 0800 MST | 11/23/2017 AT 1100 MST  
|  
CAPE... 0.0 LI... +4.4 | CAPE... 0.0 LI... +3.9  
CINH... 0.0 K INDEX... +4.5 | CINH... 0.0 K INDEX... +5.2  
|  
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 -68.5 -91.3 320 32 17 0.2 0.1 | -68.1 -90.6 315 29 15 0.5 0.3  
45000 -66.8 -88.2 320 41 21 5.6 3.1 | -66.1 -87.0 315 36 18 5.6 3.1  
40000 -58.4 -73.1 320 42 22 6.8 3.7 | -57.7 -71.9 315 40 21 6.5 3.6  
38000 -53.8 -64.8 320 38 20 7.6 4.2 | -52.7 -62.9 315 35 18 7.4 4.0  
36000 -48.6 -55.5 320 34 17 7.7 4.2 | -48.3 -54.9 320 31 16 7.4 4.0  
34000 -43.9 -47.0 320 31 16 7.9 4.3 | -43.7 -46.7 315 28 14 7.7 4.2  
32000 -39.2 -38.6 325 28 14 7.9 4.3 | -39.1 -38.4 315 26 13 7.8 4.3  
30000 -34.5 -30.1 325 26 13 7.8 4.3 | -34.4 -29.9 315 24 12 8.1 4.4  
29000 -32.2 -26.0 325 26 13 7.8 4.3 | -31.9 -25.4 315 23 12 8.1 4.4  
28000 -29.9 -21.8 320 25 13 7.9 4.3 | -29.5 -21.1 315 22 11 8.1 4.5  
27000 -27.6 -17.7 320 24 12 7.4 4.1 | -27.3 -17.1 315 22 11 7.5 4.1  
26000 -25.4 -13.7 320 24 12 7.4 4.1 | -25.0 -13.0 315 22 11 7.5 4.1  
25000 -23.2 -9.8 320 23 12 7.4 4.1 | -22.8 -9.0 315 22 11 7.5 4.1  
24000 -21.0 -5.8 320 22 11 7.7 4.2 | -20.6 -5.1 315 22 11 7.0 3.8  
23000 -18.7 -1.7 320 21 11 7.7 4.2 | -18.6 -1.5 310 21 11 7.0 3.8  
22000 -16.4 2.5 320 20 11 7.7 4.2 | -16.1 3.0 310 21 11 7.0 3.8  
21000 -13.7 7.3 325 20 10 6.8 3.7 | -14.1 6.6 310 20 10 6.7 3.7  
20000 -11.7 10.9 325 20 10 6.8 3.7 | -12.1 10.2 315 19 10 6.7 3.7  
19500 -10.7 12.7 325 20 10 6.9 3.8 | -11.1 12.0 315 19 10 6.8 3.7  
19000 -9.7 14.5 330 19 10 6.4 3.5 | -10.1 13.8 315 19 10 6.3 3.5  
18500 -8.7 16.3 330 19 10 6.4 3.5 | -9.1 15.6 315 18 9 6.3 3.5  
18000 -7.7 18.1 330 19 10 6.2 3.4 | -8.2 17.2 320 18 9 6.5 3.6  
17500 -6.9 19.6 330 18 9 5.7 3.2 | -7.1 19.2 320 17 9 6.8 3.7  
17000 -6.1 21.0 335 17 9 5.8 3.2 | -6.1 21.0 320 17 9 6.8 3.7  
16500 -5.2 22.6 335 16 8 5.5 3.0 | -5.0 23.0 325 16 8 6.8 3.7  
16000 -4.5 23.9 335 15 8 5.5 3.0 | -4.0 24.8 325 16 8 6.8 3.7  
15500 -3.7 25.3 335 14 7 5.6 3.1 | -3.0 26.6 325 15 8 6.5 3.6  
15000 -2.9 26.8 335 12 6 5.7 3.1 | -2.0 28.4 325 14 7 6.4 3.5  
14500 -2.1 28.2 340 11 6 5.7 3.1 | -1.1 30.0 330 13 7 6.4 3.5  
14000 -1.3 29.7 340 10 5 5.8 3.2 | -0.2 31.6 330 12 6 6.4 3.5  
13500 -0.4 31.3 340 9 5 5.8 3.2 | 0.7 33.3 330 11 6 6.4 3.5  
13000 0.4 32.7 335 8 4 5.3 2.9 | 1.7 35.1 330 10 5 6.5 3.5  
12500 1.2 34.2 330 7 3 5.9 3.2 | 2.6 36.7 325 9 5 7.0 3.8  
12000 1.9 35.4 325 6 3 5.2 2.8 | 3.5 38.3 325 8 4 6.0 3.3  
11750 2.3 36.1 320 6 3 5.7 3.1 | 4.0 39.2 320 8 4 6.5 3.6  
11500 2.7 36.9 310 6 3 4.1 2.3 | 4.4 39.9 320 7 4 5.1 2.8  
11250 2.9 37.2 310 6 3 4.7 2.6 | 4.7 40.5 315 7 4 4.9 2.7  
11000 3.4 38.1 305 6 3 6.7 3.7 | 5.1 41.2 315 7 4 6.1 3.3  
10750 3.9 39.0 305 5 3 6.2 3.4 | 5.5 41.9 310 7 4 5.8 3.2  
10500 4.3 39.7 300 5 3 6.3 3.4 | 5.9 42.6 305 7 4 5.8 3.2  
10250 4.8 40.6 300 5 3 7.1 3.9 | 6.3 43.3 305 7 4 5.0 2.8  
10000 5.4 41.7 305 5 3 7.8 4.3 | 6.7 44.1 305 6 3 4.6 2.5  
9750 5.9 42.6 310 5 2 7.6 4.2 | 7.0 44.6 300 6 3 4.7 2.6  
9500 6.5 43.7 320 5 2 7.8 4.3 | 7.3 45.1 300 5 3 4.7 2.6  
9250 7.1 44.8 320 4 2 6.9 3.8 | 7.7 45.9 305 5 3 6.0 3.3  
9000 7.5 45.5 315 4 2 5.0 2.8 | 8.2 46.8 310 5 2 7.2 3.9  
8750 7.8 46.0 310 4 2 4.9 2.7 | 8.7 47.7 310 4 2 7.1 3.9  
8500 8.2 46.8 300 4 2 3.9 2.1 | 9.2 48.6 310 4 2 7.3 4.0  
8250 8.4 47.1 295 4 2 1.8 1.0 | 9.8 49.6 310 4 2 7.6 4.2  
8000 8.3 46.9 285 4 2 -8.0 -4.4 | 10.4 50.7 305 4 2 12.1 6.6  
7750 6.9 44.4 275 4 2 -30.5 -16.7 | 11.5 52.7 295 3 2 19.1 10.5  
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  
 
11/23/2017 AT 1400 MST | 11/23/2017 AT 1700 MST  
|  
CAPE... 0.0 LI... +2.7 | CAPE... 0.0 LI... +1.7  
CINH... 0.0 K INDEX... +5.5 | CINH... 0.0 K INDEX... +4.8  
|  
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 -68.3 -90.9 310 30 15 1.2 0.6 | -68.9 -92.0 310 31 16 1.7 0.9  
45000 -65.5 -85.9 315 35 18 4.9 2.7 | -65.5 -85.9 310 36 19 4.9 2.7  
40000 -58.1 -72.6 310 38 20 6.5 3.6 | -58.3 -72.9 305 37 19 6.4 3.5  
38000 -53.4 -64.1 310 35 18 7.9 4.4 | -53.5 -64.3 305 34 17 7.9 4.4  
36000 -48.0 -54.4 305 32 16 7.9 4.4 | -48.7 -55.7 300 31 16 7.9 4.4  
34000 -43.4 -46.1 305 29 15 7.7 4.2 | -43.4 -46.1 300 29 15 7.9 4.3  
32000 -38.7 -37.7 305 26 13 7.7 4.2 | -38.7 -37.7 300 28 14 7.9 4.4  
30000 -34.2 -29.6 305 24 12 7.6 4.2 | -34.1 -29.4 300 26 13 7.4 4.1  
29000 -31.9 -25.4 305 23 12 7.6 4.2 | -31.9 -25.4 300 25 13 7.4 4.1  
28000 -29.6 -21.3 305 23 12 7.5 4.1 | -29.7 -21.5 295 24 12 7.4 4.1  
27000 -27.3 -17.1 305 22 11 8.0 4.4 | -27.5 -17.5 295 23 12 7.4 4.0  
26000 -24.9 -12.8 305 22 11 8.0 4.4 | -25.3 -13.5 295 22 11 7.4 4.0  
25000 -22.5 -8.5 305 21 11 8.0 4.4 | -23.1 -9.6 295 20 10 7.4 4.0  
24000 -20.3 -4.5 305 21 11 6.7 3.7 | -20.9 -5.6 295 20 10 7.0 3.9  
23000 -18.3 -0.9 305 21 11 6.7 3.7 | -18.8 -1.8 300 19 10 7.0 3.9  
22000 -16.4 2.5 305 22 11 6.7 3.7 | -16.7 1.9 310 20 10 7.0 3.9  
21000 -14.1 6.6 310 21 11 6.1 3.3 | -14.5 5.9 315 19 10 5.4 2.9  
20000 -12.3 9.9 310 20 10 6.1 3.3 | -12.9 8.8 315 19 10 5.4 3.0  
19500 -11.4 11.5 310 20 10 6.1 3.3 | -12.1 10.2 315 19 10 5.4 2.9  
19000 -10.5 13.1 310 20 10 6.3 3.5 | -11.3 11.7 320 19 10 6.4 3.5  
18500 -9.5 14.9 315 19 10 6.3 3.5 | -10.3 13.5 320 19 10 6.6 3.6  
18000 -8.6 16.5 315 19 10 6.5 3.5 | -9.4 15.1 320 19 10 6.9 3.8  
17500 -7.6 18.3 315 19 10 6.8 3.7 | -8.2 17.2 320 19 10 7.9 4.3  
17000 -6.6 20.1 315 18 10 6.7 3.7 | -7.1 19.2 320 19 10 7.9 4.3  
16500 -5.6 21.9 315 18 9 7.8 4.3 | -5.9 21.4 320 19 10 7.6 4.2  
16000 -4.4 24.1 320 18 9 7.7 4.3 | -4.8 23.4 320 19 10 7.6 4.2  
15500 -3.2 26.2 320 18 9 7.6 4.2 | -3.7 25.3 320 18 9 7.9 4.3  
15000 -2.0 28.4 320 17 9 7.6 4.2 | -2.5 27.5 320 17 9 8.1 4.4  
14500 -0.8 30.6 320 17 9 7.4 4.1 | -1.3 29.7 320 17 9 8.0 4.4  
14000 0.2 32.4 320 16 8 6.7 3.7 | -0.1 31.8 320 16 8 7.6 4.2  
13500 1.3 34.3 320 16 8 6.7 3.7 | 1.0 33.8 320 16 8 7.7 4.2  
13000 2.3 36.1 320 14 7 6.6 3.6 | 2.1 35.8 320 15 8 6.6 3.6  
12500 3.2 37.8 315 13 7 6.1 3.3 | 3.0 37.4 320 14 7 5.5 3.0  
12000 4.1 39.4 315 12 6 6.1 3.3 | 3.9 39.0 320 12 6 6.4 3.5  
11750 4.5 40.1 315 11 6 6.0 3.3 | 4.4 39.9 320 11 6 6.3 3.4  
11500 5.0 41.0 310 11 6 6.8 3.7 | 4.8 40.6 315 10 5 6.9 3.8  
11250 5.5 41.9 310 10 5 6.6 3.6 | 5.3 41.5 315 10 5 7.1 3.9  
11000 5.9 42.6 310 9 5 5.8 3.2 | 5.8 42.4 315 9 5 6.7 3.7  
10750 6.3 43.3 310 9 5 5.5 3.0 | 6.3 43.3 310 9 5 6.8 3.7  
10500 6.7 44.1 305 8 4 7.7 4.2 | 6.7 44.1 305 9 4 6.8 3.7  
10250 7.3 45.1 305 7 4 9.3 5.1 | 7.2 45.0 300 9 4 7.9 4.3  
10000 7.9 46.2 300 6 3 8.1 4.4 | 7.8 46.0 295 8 4 8.9 4.9  
9750 8.5 47.3 295 6 3 8.5 4.7 | 8.4 47.1 290 8 4 8.7 4.8  
9500 9.0 48.2 290 5 3 8.1 4.4 | 9.0 48.2 285 8 4 9.1 5.0  
9250 9.6 49.3 285 4 2 8.1 4.4 | 9.7 49.5 285 7 4 7.8 4.3  
9000 10.2 50.4 290 4 2 10.0 5.5 | 10.2 50.4 285 7 3 8.4 4.6  
8750 11.0 51.8 285 4 2 11.1 6.1 | 10.9 51.6 285 6 3 10.0 5.5  
8500 11.8 53.2 285 4 2 10.6 5.8 | 11.6 52.9 280 6 3 9.6 5.3  
8250 12.6 54.7 285 4 2 9.8 5.4 | 12.3 54.1 280 5 3 7.1 3.9  
8000 13.4 56.1 285 4 2 12.0 6.6 | 12.5 54.5 275 4 2 -0.2 -0.1  
7750 14.4 57.9 285 3 2 16.8 9.2 | 12.2 54.0 270 3 1 -6.2 -3.4  
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  
 
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