648  
UXUS97 KPUB 081212  
SRGPUB  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE PUEBLO, COLORADO  
0512 MST THURSDAY, DECEMBER 8, 2022  
 
THIS FORECAST IS FOR THE AIR FORCE ACADEMY FOR THURSDAY, DECEMBER 8, 2022:  
 
IF THE TRIGGER TEMPERATURE OF 43.4 F/6.3 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... FAIR  
MAXIMUM RATE OF LIFT........................ 653 FT/MIN (3.3 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 14783 FT MSL (7168 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 48.0 F/9.3 C  
TIME OF TRIGGER TEMPERATURE.................... 1145 MST  
TIME OF OVERDEVELOPMENT........................ NONE  
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... NONE  
SURFACE WINDS DURING SOARING WINDOW............ BETWEEN 20 MPH AND 30 MPH  
HEIGHT OF THE -3 THERMAL INDEX................. 11010 FT MSL (3395 FT AGL)  
THERMAL SOARING OUTLOOK FOR FRIDAY 12/09....... POOR  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
SUNRISE/SUNSET.................... 07:05:48 / 16:36:48 MST  
TOTAL POSSIBLE SUNSHINE........... 9 HR 31 MIN 0 SEC (571 MIN 0 SEC)  
ALTITUDE OF SUN AT 11:51:18 MST... 28.22 DEGREES  
 
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 12/08/2022 AT 0500 MST  
 
FREEZING LEVEL.................. ENTIRE AIRMASS BELOW 32 F / 0 C  
CONVECTIVE CONDENSATION LEVEL... 14949 FT MSL (7334 FT AGL)  
LIFTED CONDENSATION LEVEL....... 14994 FT MSL (7379 FT AGL)  
LIFTED INDEX.................... +3.7  
K INDEX......................... -16.8  
 
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 -61.3 -78.3 245 43 22 3.5 1.9 M M M M M  
45000 -56.1 -69.0 245 49 25 3.0 1.7 M M M M M  
40000 -54.3 -65.7 245 44 23 1.1 0.6 M M M M M  
38000 -52.7 -62.9 245 43 22 4.1 2.2 M M M M M  
36000 -50.3 -58.5 250 41 21 4.1 2.2 M M M M M  
34000 -47.8 -54.0 250 40 21 3.7 2.0 M M M M M  
32000 -45.6 -50.1 250 39 20 3.7 2.0 M M M M M  
30000 -43.3 -45.9 245 38 20 5.3 2.9 26.6 79.9 13.6 M M  
29000 -41.6 -42.9 250 37 19 5.5 3.0 24.8 76.6 12.4 M M  
28000 -40.0 -40.0 250 36 19 5.5 3.0 23.2 73.7 11.2 M M  
27000 -38.3 -36.9 250 35 18 5.6 3.1 21.7 71.0 10.2 M M  
26000 -36.7 -34.1 250 34 17 5.2 2.8 20.0 67.9 8.9 M M  
25000 -35.2 -31.4 250 33 17 5.1 2.8 18.2 64.8 7.6 M M  
24000 -33.2 -27.8 250 32 17 5.3 2.9 16.2 61.2 6.1 M M  
23000 -31.2 -24.2 250 31 16 7.3 4.0 15.1 59.2 5.3 M M  
22000 -29.0 -20.2 250 29 15 7.3 4.0 14.2 57.6 4.6 M M  
21000 -26.8 -16.2 245 27 14 8.1 4.4 13.5 56.3 4.0 M M  
20000 -24.2 -11.6 245 27 14 8.7 4.8 13.0 55.4 3.6 M M  
19500 -22.9 -9.2 245 26 14 8.7 4.8 12.8 55.1 3.5 M M  
19000 -21.6 -6.9 245 26 13 8.6 4.7 12.7 54.8 3.3 M M  
18500 -20.3 -4.5 245 26 13 7.7 4.2 12.5 54.6 3.2 M M  
18000 -19.3 -2.7 245 25 13 6.6 3.6 12.0 53.6 2.8 M M  
17500 -18.3 -0.9 245 24 12 6.5 3.6 11.5 52.6 2.3 M M  
17000 -17.3 0.9 245 22 11 6.4 3.5 10.9 51.7 1.8 M M  
16500 -16.4 2.5 240 19 10 6.5 3.6 10.4 50.7 1.3 M M  
16000 -15.4 4.3 240 16 8 7.3 4.0 9.9 49.8 0.8 M M  
15500 -14.3 6.3 240 15 8 7.6 4.2 9.5 49.1 0.5 M M  
15000 -13.2 8.2 240 14 7 7.9 4.3 9.2 48.5 0.1 M M  
14500 -12.0 10.4 240 12 6 8.2 4.5 8.9 48.0 -0.1 626 3.2  
14000 -10.8 12.6 240 11 6 8.0 4.4 8.7 47.6 -0.4 575 2.9  
13500 -9.7 14.5 240 11 6 7.4 4.1 8.3 46.9 -0.8 527 2.7  
13000 -8.6 16.5 245 11 6 7.8 4.3 7.9 46.3 -1.1 479 2.4  
12500 -7.4 18.7 245 11 6 6.6 3.6 7.7 45.8 -1.4 429 2.2  
12000 -6.6 20.1 255 11 6 5.8 3.2 7.0 44.6 -2.1 390 2.0  
11750 -6.1 21.0 260 11 6 7.7 4.2 6.7 44.1 -2.4 368 1.9  
11500 -5.5 22.1 260 11 6 8.2 4.5 6.6 43.9 -2.5 342 1.7  
11250 -5.0 23.0 260 11 5 6.8 3.7 6.4 43.6 -2.7 319 1.6  
11000 -4.5 23.9 265 11 6 6.4 3.5 6.2 43.1 -2.9 297 1.5  
10750 -4.0 24.8 270 11 6 6.2 3.4 5.9 42.6 -3.2 276 1.4  
10500 -3.6 25.5 270 13 7 5.6 3.1 5.6 42.1 -3.5 255 1.3  
10250 -3.2 26.2 270 14 7 7.1 3.9 5.3 41.6 -3.8 235 1.2  
10000 -2.6 27.3 270 15 8 7.7 4.2 5.2 41.4 -4.0 210 1.1  
9750 -2.1 28.2 270 16 8 5.9 3.2 5.0 40.9 -4.3 188 1.0  
9500 -1.7 28.9 270 17 9 5.4 3.0 4.6 40.3 -4.6 169 0.9  
9250 -1.3 29.7 270 18 9 5.8 3.2 4.3 39.8 -4.9 149 0.8  
9000 -0.9 30.4 270 19 10 4.3 2.4 4.0 39.2 -5.3 131 0.7  
8750 -0.7 30.7 265 19 10 2.7 1.5 3.5 38.3 -5.8 117 0.6  
8500 -0.5 31.1 265 18 9 3.1 1.7 3.0 37.3 -6.4 103 0.5  
8250 -0.3 31.5 265 17 9 2.2 1.2 2.4 36.4 -6.9 90 0.5  
8000 -0.3 31.5 260 16 8 -2.3 -1.2 1.7 35.1 -7.7 83 0.4  
7750 -0.7 30.7 260 11 6 -7.1 -3.9 0.6 33.1 -8.8 87 0.4  
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 * * * * * *  
 
12/08/2022 AT 0800 MST | 12/08/2022 AT 1100 MST  
|  
CAPE... 0.0 LI... +6.5 | CAPE... 0.0 LI... +8.7  
CINH... 0.0 K INDEX... -43.0' | CINH... 0.0 K INDEX... -47.8'  
|  
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 -62.3 -80.1 245 43 22 2.1 1.2 | -62.1 -79.8 245 45 23 2.3 1.2  
45000 -59.0 -74.2 245 48 25 2.2 1.2 | -58.7 -73.7 245 51 26 2.1 1.1  
40000 -55.1 -67.2 250 51 26 2.5 1.4 | -56.2 -69.2 250 53 27 1.6 0.9  
38000 -52.9 -63.2 255 51 26 4.7 2.6 | -54.1 -65.4 250 53 27 5.1 2.8  
36000 -50.1 -58.2 255 50 26 4.7 2.6 | -51.0 -59.8 250 54 28 5.1 2.8  
34000 -47.3 -53.1 255 49 25 5.0 2.7 | -47.9 -54.2 250 54 28 5.5 3.0  
32000 -44.3 -47.7 250 47 24 5.0 2.7 | -44.6 -48.3 250 51 26 5.5 3.0  
30000 -41.3 -42.3 250 44 23 5.1 2.8 | -41.4 -42.5 250 49 25 5.1 2.8  
29000 -39.8 -39.6 250 43 22 5.1 2.8 | -39.8 -39.6 250 46 24 5.1 2.8  
28000 -38.2 -36.8 250 42 22 5.1 2.8 | -38.3 -36.9 250 44 23 5.1 2.8  
27000 -36.7 -34.1 250 41 21 5.0 2.7 | -36.8 -34.2 250 42 22 4.9 2.7  
26000 -35.0 -31.0 250 40 20 6.1 3.3 | -34.8 -30.6 250 41 21 7.1 3.9  
25000 -33.1 -27.6 250 39 20 6.1 3.3 | -32.7 -26.9 250 40 20 7.1 3.9  
24000 -31.3 -24.3 250 38 19 6.1 3.3 | -30.5 -22.9 255 39 20 7.1 3.9  
23000 -28.8 -19.8 250 36 19 7.0 3.8 | -27.8 -18.0 255 38 19 7.5 4.1  
22000 -26.7 -16.1 250 36 18 7.0 3.8 | -25.5 -13.9 250 36 19 7.5 4.1  
21000 -24.6 -12.3 250 35 18 6.6 3.6 | -23.2 -9.8 250 35 18 7.1 3.9  
20000 -22.7 -8.9 250 32 17 6.3 3.5 | -21.2 -6.2 255 33 17 6.9 3.8  
19500 -21.8 -7.2 250 31 16 6.3 3.5 | -20.2 -4.4 260 32 17 6.9 3.8  
19000 -20.8 -5.4 250 30 15 6.3 3.4 | -19.1 -2.4 260 31 16 6.8 3.7  
18500 -19.9 -3.8 245 29 15 5.9 3.2 | -18.1 -0.6 265 31 16 5.5 3.0  
18000 -19.1 -2.4 245 27 14 5.1 2.8 | -17.6 0.3 265 29 15 2.9 1.6  
17500 -18.3 -0.9 245 26 13 5.1 2.8 | -17.1 1.2 270 27 14 2.9 1.6  
17000 -17.6 0.3 245 25 13 5.4 2.9 | -16.7 1.9 275 25 13 2.9 1.6  
16500 -16.7 1.9 245 24 12 5.4 2.9 | -16.3 2.7 280 23 12 2.9 1.6  
16000 -16.0 3.2 245 24 12 4.9 2.7 | -15.8 3.6 285 22 11 2.8 1.5  
15500 -15.3 4.5 250 22 12 4.6 2.5 | -15.4 4.3 290 22 11 2.8 1.5  
15000 -14.6 5.7 255 21 11 3.9 2.2 | -15.0 5.0 295 21 11 3.4 1.8  
14500 -14.1 6.6 260 19 10 2.8 1.5 | -14.4 6.1 295 21 11 4.4 2.4  
14000 -13.7 7.3 265 18 9 3.9 2.1 | -13.7 7.3 300 21 11 4.4 2.4  
13500 -12.6 9.3 265 15 8 9.9 5.4 | -13.1 8.4 295 21 11 4.3 2.4  
13000 -11.2 11.8 260 12 6 9.8 5.4 | -12.5 9.5 295 22 11 4.5 2.5  
12500 -9.5 14.9 260 12 6 9.6 5.3 | -11.6 11.1 290 21 11 5.0 2.8  
12000 -8.4 16.9 255 10 5 7.4 4.1 | -11.1 12.0 285 18 9 4.0 2.2  
11750 -7.9 17.8 255 10 5 7.0 3.9 | -10.8 12.6 280 18 9 5.9 3.2  
11500 -7.4 18.7 255 11 5 6.8 3.7 | -10.3 13.5 280 18 9 7.0 3.8  
11250 -6.9 19.6 255 11 6 6.5 3.6 | -9.8 14.4 280 18 9 6.6 3.6  
11000 -6.4 20.5 260 12 6 6.0 3.3 | -9.3 15.3 280 18 9 6.7 3.7  
10750 -6.0 21.2 260 13 7 4.7 2.6 | -8.8 16.2 280 18 9 7.2 3.9  
10500 -5.7 21.7 265 14 7 4.0 2.2 | -8.3 17.1 280 18 9 6.6 3.6  
10250 -5.4 22.3 265 16 8 4.1 2.3 | -7.8 18.0 280 17 9 9.1 5.0  
10000 -5.2 22.6 270 17 9 3.4 1.9 | -7.0 19.4 280 17 9 11.0 6.0  
9750 -5.0 23.0 270 18 9 2.8 1.5 | -6.3 20.7 280 16 8 9.6 5.2  
9500 -4.8 23.4 275 19 10 2.1 1.1 | -5.6 21.9 280 16 8 9.3 5.1  
9250 -4.6 23.7 275 20 10 4.2 2.3 | -4.9 23.2 280 15 8 9.9 5.4  
9000 -4.2 24.4 280 22 11 7.0 3.8 | -4.1 24.6 275 15 8 10.3 5.7  
8750 -3.7 25.3 280 21 11 6.7 3.7 | -3.3 26.1 275 14 7 10.3 5.6  
8500 -3.2 26.2 280 20 10 6.6 3.6 | -2.6 27.3 280 14 7 10.1 5.5  
8250 -2.7 27.1 280 19 10 6.4 3.5 | -1.8 28.8 280 13 7 10.9 6.0  
8000 -2.3 27.9 280 17 9 6.5 3.5 | -0.8 30.6 280 13 7 15.7 8.6  
7750 -1.8 28.8 280 13 7 7.1 3.9 | 0.6 33.1 280 11 6 21.3 11.7  
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  
 
12/08/2022 AT 1400 MST | 12/08/2022 AT 1700 MST  
|  
CAPE... 0.0 LI... +7.4 | CAPE... 0.0 LI... +7.2  
CINH... 0.0 K INDEX... -41.7' | CINH... 0.0 K INDEX... -36.5'  
|  
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 -60.8 -77.4 250 45 23 2.4 1.3 | -61.2 -78.2 250 43 22 2.1 1.1  
45000 -57.2 -71.0 250 52 27 2.2 1.2 | -58.1 -72.6 250 51 26 2.1 1.1  
40000 -54.8 -66.6 250 56 29 1.5 0.8 | -54.8 -66.6 255 54 28 2.1 1.1  
38000 -53.5 -64.3 250 57 29 3.0 1.7 | -53.4 -64.1 255 53 27 2.8 1.5  
36000 -51.6 -60.9 250 58 30 3.0 1.7 | -51.7 -61.1 255 51 26 2.8 1.6  
34000 -49.7 -57.5 250 57 30 5.2 2.8 | -49.8 -57.6 255 49 25 4.8 2.6  
32000 -46.7 -52.1 250 53 27 5.1 2.8 | -47.0 -52.6 255 45 23 4.7 2.6  
30000 -43.6 -46.5 250 48 25 5.5 3.0 | -44.2 -47.6 255 41 21 5.7 3.1  
29000 -42.0 -43.6 250 45 23 5.4 3.0 | -42.5 -44.5 255 39 20 5.6 3.1  
28000 -40.3 -40.5 255 43 22 5.4 3.0 | -40.8 -41.4 260 37 19 5.6 3.1  
27000 -38.7 -37.7 255 41 21 5.2 2.9 | -39.1 -38.4 260 35 18 5.4 3.0  
26000 -36.6 -33.9 255 39 20 7.7 4.2 | -37.0 -34.6 260 34 17 7.4 4.0  
25000 -34.3 -29.7 255 38 20 7.7 4.2 | -34.8 -30.6 260 33 17 7.4 4.0  
24000 -31.4 -24.5 255 37 19 7.7 4.2 | -32.1 -25.8 265 31 16 7.5 4.1  
23000 -29.0 -20.2 255 35 18 7.8 4.3 | -29.7 -21.5 265 30 15 7.8 4.3  
22000 -26.7 -16.1 255 33 17 7.8 4.3 | -27.4 -17.3 265 29 15 7.8 4.3  
21000 -24.3 -11.7 255 31 16 7.4 4.0 | -25.0 -13.0 265 28 14 7.9 4.3  
20000 -22.2 -8.0 260 29 15 7.1 3.9 | -22.6 -8.7 270 26 13 7.9 4.3  
19500 -21.1 -6.0 265 28 14 7.0 3.9 | -21.5 -6.7 270 26 13 7.9 4.3  
19000 -20.1 -4.2 265 27 14 6.9 3.8 | -20.3 -4.5 270 25 13 7.8 4.3  
18500 -19.0 -2.2 270 26 13 5.1 2.8 | -19.1 -2.4 270 24 12 6.4 3.5  
18000 -18.6 -1.5 275 25 13 2.2 1.2 | -18.4 -1.1 275 23 12 5.1 2.8  
17500 -18.3 -0.9 275 24 13 2.2 1.2 | -17.6 0.3 275 23 12 5.0 2.8  
17000 -18.0 -0.4 280 24 12 2.2 1.2 | -17.0 1.4 280 22 11 2.7 1.5  
16500 -17.6 0.3 285 23 12 2.1 1.2 | -16.6 2.1 285 21 11 2.9 1.6  
16000 -17.2 1.0 290 22 11 5.2 2.9 | -16.2 2.8 285 20 10 3.2 1.7  
15500 -16.2 2.8 290 20 11 6.3 3.4 | -15.7 3.7 290 19 10 3.3 1.8  
15000 -15.3 4.5 290 19 10 6.3 3.5 | -15.2 4.6 295 18 9 4.8 2.6  
14500 -14.4 6.1 295 19 10 6.3 3.5 | -14.3 6.3 295 16 8 6.1 3.3  
14000 -13.4 7.9 300 18 9 6.7 3.7 | -13.4 7.9 300 15 8 6.7 3.7  
13500 -12.3 9.9 305 16 8 7.9 4.4 | -12.2 10.0 300 12 6 7.8 4.3  
13000 -11.1 12.0 305 14 7 8.5 4.6 | -11.1 12.0 300 10 5 8.6 4.7  
12500 -9.6 14.7 305 14 7 8.9 4.9 | -9.5 14.9 305 10 5 9.7 5.3  
12000 -8.5 16.7 305 15 8 7.1 3.9 | -8.2 17.2 305 9 5 8.6 4.7  
11750 -8.0 17.6 305 15 8 6.4 3.5 | -7.6 18.3 305 10 5 7.9 4.4  
11500 -7.6 18.3 300 16 8 5.0 2.7 | -7.0 19.4 305 10 5 7.8 4.3  
11250 -7.4 18.7 300 17 9 1.3 0.7 | -6.4 20.5 305 11 6 9.0 4.9  
11000 -7.4 18.7 300 18 9 0.8 0.4 | -5.8 21.6 305 12 6 6.7 3.7  
10750 -7.2 19.0 295 18 9 4.0 2.2 | -5.5 22.1 305 13 7 2.3 1.3  
10500 -6.9 19.6 295 17 9 3.9 2.1 | -5.3 22.5 300 14 7 2.5 1.4  
10250 -6.6 20.1 290 16 8 6.8 3.7 | -5.2 22.6 300 14 7 0.1 0.1  
10000 -5.9 21.4 290 15 8 10.4 5.7 | -5.3 22.5 295 15 8 1.7 0.9  
9750 -5.2 22.6 290 15 8 9.7 5.3 | -4.9 23.2 295 15 7 6.2 3.4  
9500 -4.5 23.9 290 15 8 9.6 5.3 | -4.5 23.9 290 14 7 5.2 2.8  
9250 -3.7 25.3 290 15 8 10.1 5.5 | -4.1 24.6 290 13 7 7.1 3.9  
9000 -3.0 26.6 290 15 7 10.1 5.6 | -3.5 25.7 285 12 6 9.3 5.1  
8750 -2.2 28.0 290 14 7 9.8 5.4 | -2.8 27.0 290 12 6 9.1 5.0  
8500 -1.5 29.3 290 14 7 9.6 5.2 | -2.1 28.2 290 11 6 9.7 5.3  
8250 -0.8 30.6 290 13 7 10.9 6.0 | -1.5 29.3 290 10 5 7.6 4.1  
8000 0.2 32.4 290 13 7 14.8 8.1 | -1.2 29.8 290 10 5 -3.0 -1.6  
7750 2.6 36.7 295 9 4 14.4 7.9 | -1.9 28.6 290 7 3 -14.0 -7.7  
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). 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  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab CO Page Main Text Page