595  
UXUS97 KPUB 101209  
SRGPUB  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE PUEBLO, COLORADO  
0607 MDT THURSDAY, JULY 10, 2025  
 
THIS FORECAST IS FOR VILLA GROVE, CO FOR THURSDAY, JULY 10, 2025:  
 
IF THE TRIGGER TEMPERATURE OF 73.2 F/22.9 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... GOOD  
MAXIMUM RATE OF LIFT........................ 1285 FT/MIN (6.5 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 23320 FT MSL (14327 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 82.0 F/28.2 C  
TIME OF TRIGGER TEMPERATURE.................... 1015 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................. 19033 FT MSL (10039 FT AGL)  
THERMAL SOARING OUTLOOK FOR FRIDAY 07/11....... EXCELLENT  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
SUNRISE/SUNSET.................... 05:49:23 / 20:28:44 MDT  
TOTAL POSSIBLE SUNSHINE........... 14 HR 39 MIN 21 SEC (879 MIN 21 SEC)  
ALTITUDE OF SUN AT 13:09:04 MDT... 73.74 DEGREES  
 
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 07/10/2025 AT 0600 MDT  
 
FREEZING LEVEL.................. 16902 FT MSL (7909 FT AGL)  
CONVECTIVE CONDENSATION LEVEL... 20017 FT MSL (11024 FT AGL)  
LIFTED CONDENSATION LEVEL....... 21159 FT MSL (12165 FT AGL)  
LIFTED INDEX.................... -2.6  
K INDEX......................... +21.1  
 
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 -64.4 -83.9 275 30 15 0.7 0.4 M M M M M  
45000 -60.3 -76.5 280 44 23 6.1 3.3 M M M M M  
40000 -51.0 -59.8 285 53 27 7.2 3.9 M M M M M  
38000 -46.7 -52.1 285 51 26 7.1 3.9 M M M M M  
36000 -42.4 -44.3 280 50 26 7.1 3.9 M M M M M  
34000 -38.2 -36.8 280 47 24 7.0 3.8 M M M M M  
32000 -33.5 -28.3 280 44 22 7.0 3.8 M M M M M  
30000 -29.3 -20.7 280 39 20 7.0 3.9 34.4 93.9 5.2 M M  
29000 -27.3 -17.1 280 37 19 7.1 3.9 33.4 92.2 4.5 M M  
28000 -25.2 -13.4 280 35 18 7.1 3.9 32.5 90.5 3.8 M M  
27000 -23.0 -9.4 280 34 17 7.2 3.9 31.5 88.6 2.9 M M  
26000 -20.9 -5.6 280 32 17 7.2 4.0 30.6 87.0 2.2 M M  
25000 -18.8 -1.8 280 30 16 7.2 4.0 29.8 85.6 1.5 M M  
24000 -16.7 1.9 280 29 15 7.2 3.9 28.8 83.8 0.6 M M  
23000 -14.6 5.7 275 29 15 7.2 4.0 27.9 82.2 -0.2 1457 7.4  
22000 -12.5 9.5 270 28 14 7.5 4.1 27.1 80.8 -1.0 1364 6.9  
21000 -10.2 13.6 265 28 14 7.6 4.2 26.3 79.3 -1.7 1267 6.4  
20000 -8.0 17.6 265 28 15 7.6 4.2 25.6 78.0 -2.4 1170 5.9  
19500 -6.9 19.6 260 28 15 7.7 4.2 25.3 77.5 -2.7 1121 5.7  
19000 -5.6 21.9 260 28 14 8.5 4.7 25.0 77.0 -3.0 1070 5.4  
18500 -4.4 24.1 260 27 14 8.5 4.6 24.8 76.6 -3.2 1018 5.2  
18000 -3.1 26.4 255 25 13 8.7 4.8 24.6 76.3 -3.4 965 4.9  
17500 -1.8 28.8 255 24 13 8.8 4.8 24.4 76.0 -3.6 912 4.6  
17000 -0.6 30.9 260 23 12 8.8 4.8 24.3 75.7 -3.8 859 4.4  
16500 1.4 34.5 260 23 12 8.9 4.9 24.1 75.3 -4.1 778 4.0  
16000 2.7 36.9 265 23 12 9.0 4.9 23.9 75.1 -4.3 725 3.7  
15500 4.0 39.2 265 23 12 9.2 5.1 23.8 74.9 -4.4 669 3.4  
15000 5.4 41.7 270 23 12 9.2 5.0 23.8 74.8 -4.5 613 3.1  
14500 6.8 44.2 270 23 12 9.4 5.2 23.7 74.7 -4.6 556 2.8  
14000 8.2 46.8 270 23 12 9.0 4.9 23.6 74.5 -4.7 501 2.5  
13500 9.7 49.5 275 23 12 11.7 6.4 23.7 74.6 -4.7 441 2.2  
13000 11.1 52.0 275 22 11 7.4 4.1 23.6 74.5 -4.8 383 1.9  
12500 12.3 54.1 275 21 11 8.6 4.7 23.4 74.0 -5.0 333 1.7  
12000 13.6 56.5 275 21 11 8.2 4.5 23.2 73.8 -5.2 277 1.4  
11750 14.2 57.6 275 21 11 7.7 4.2 23.1 73.5 -5.3 253 1.3  
11500 14.8 58.6 275 21 11 7.3 4.0 22.9 73.3 -5.5 228 1.2  
11250 15.3 59.5 275 20 10 6.8 3.7 22.7 72.9 -5.7 206 1.0  
11000 15.8 60.4 275 19 10 6.5 3.6 22.5 72.5 -6.0 183 0.9  
10750 16.3 61.3 270 18 9 8.6 4.7 22.3 72.1 -6.2 160 0.8  
10500 16.9 62.4 270 18 9 4.2 2.3 22.1 71.8 -6.4 136 0.7  
10250 16.9 62.4 265 17 9 -1.8 -1.0 21.4 70.5 -7.2 129 0.7  
10000 16.7 62.1 260 16 8 -2.8 -1.6 20.5 68.9 -8.1 127 0.6  
9750 16.6 61.9 255 15 8 2.4 1.3 19.6 67.3 -9.0 124 0.6  
9500 16.6 61.9 245 14 7 -7.6 -4.1 19.0 66.2 -9.6 114 0.6  
9250 14.8 58.6 240 10 5 -42.0 -23.0 16.4 61.5 -12.3 163 0.8  
9000 12.5 54.5 230 6 3 9.1 5.0 13.4 56.1 -15.3 225 1.1  
8750 M M M M M M M M M M M M  
8500 M M M M M M M M M M M M  
8250 M M M M M M M M M M M M  
8000 M M M M M M M M M M M M  
 
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *  
 
07/10/2025 AT 0900 MDT | 07/10/2025 AT 1200 MDT  
|  
CAPE... +115.2 LI... -0.3 | CAPE... +741.2 LI... -2.4  
CINH... -87.6 K INDEX... +25.8 | CINH... -0.3 K INDEX... +31.1  
|  
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 -63.6 -82.5 275 30 15 0.4 0.2 | -63.4 -82.1 275 32 16 1.2 0.6  
45000 -60.3 -76.5 280 47 24 5.5 3.0 | -59.5 -75.1 280 53 27 5.0 2.8  
40000 -51.5 -60.7 280 53 27 7.5 4.1 | -51.6 -60.9 285 57 29 6.9 3.8  
38000 -47.0 -52.6 280 54 28 7.5 4.1 | -47.5 -53.5 285 53 27 6.9 3.8  
36000 -42.5 -44.5 280 55 28 7.4 4.1 | -43.3 -45.9 285 49 25 6.9 3.8  
34000 -38.4 -37.1 280 52 27 6.8 3.7 | -39.3 -38.7 285 44 23 6.7 3.7  
32000 -33.8 -28.8 280 48 25 6.9 3.8 | -34.8 -30.6 285 38 19 7.1 3.9  
30000 -29.6 -21.3 280 45 23 7.0 3.8 | -30.1 -22.2 285 36 19 7.9 4.4  
29000 -27.5 -17.5 275 44 23 7.0 3.8 | -27.7 -17.9 285 35 18 7.9 4.4  
28000 -25.5 -13.9 275 42 22 6.1 3.4 | -25.4 -13.7 285 34 18 7.1 3.9  
27000 -23.6 -10.5 275 39 20 6.3 3.5 | -23.2 -9.8 280 34 18 7.2 3.9  
26000 -21.7 -7.1 275 35 18 6.4 3.5 | -21.1 -6.0 280 34 17 7.2 3.9  
25000 -19.9 -3.8 270 32 17 7.3 4.0 | -18.9 -2.0 275 34 17 6.6 3.6  
24000 -17.6 0.3 270 30 15 7.9 4.4 | -17.2 1.0 270 33 17 6.0 3.3  
23000 -15.2 4.6 265 28 14 8.0 4.4 | -15.4 4.3 265 33 17 6.1 3.3  
22000 -12.9 8.8 265 26 13 8.2 4.5 | -13.6 7.5 260 33 17 7.8 4.3  
21000 -10.5 13.1 265 28 14 8.3 4.5 | -11.1 12.0 260 32 17 8.9 4.9  
20000 -8.1 17.4 265 30 15 8.3 4.5 | -8.6 16.5 260 31 16 9.0 4.9  
19500 -6.9 19.6 265 31 16 8.3 4.5 | -7.3 18.9 265 31 16 9.1 5.0  
19000 -5.7 21.7 265 31 16 8.2 4.5 | -6.0 21.2 265 29 15 8.8 4.9  
18500 -4.5 23.9 265 31 16 8.3 4.5 | -4.8 23.4 265 27 14 8.9 4.9  
18000 -3.3 26.1 265 31 16 8.1 4.4 | -3.5 25.7 265 25 13 9.0 5.0  
17500 -2.1 28.2 260 30 16 8.0 4.4 | -2.2 28.0 265 22 11 9.1 5.0  
17000 -1.0 30.2 260 30 15 8.1 4.4 | -0.9 30.4 265 19 10 9.1 5.0  
16500 0.3 32.5 265 29 15 9.0 4.9 | 0.5 32.9 265 18 9 9.5 5.2  
16000 1.6 34.9 265 28 14 8.9 4.9 | 2.6 36.7 265 16 8 9.5 5.2  
15500 3.6 38.5 265 27 14 9.3 5.1 | 4.0 39.2 265 16 8 9.8 5.4  
15000 5.0 41.0 265 26 14 9.1 5.0 | 5.5 41.9 260 15 8 9.9 5.4  
14500 6.5 43.7 265 26 13 9.9 5.4 | 6.9 44.4 260 15 8 9.5 5.2  
14000 7.9 46.2 265 25 13 9.4 5.2 | 8.4 47.1 260 15 8 9.9 5.5  
13500 9.3 48.7 265 25 13 9.2 5.1 | 9.9 49.8 260 15 8 10.0 5.5  
13000 10.6 51.1 265 24 12 8.7 4.8 | 11.4 52.5 260 15 7 9.8 5.4  
12500 11.9 53.4 265 23 12 8.6 4.7 | 12.9 55.2 260 14 7 10.1 5.5  
12000 13.2 55.8 265 21 11 8.6 4.7 | 14.4 57.9 260 14 7 9.8 5.4  
11750 13.9 57.0 265 20 10 8.9 4.9 | 15.1 59.2 260 14 7 9.6 5.3  
11500 14.5 58.1 265 19 10 7.8 4.3 | 15.8 60.4 260 14 7 9.6 5.3  
11250 15.0 59.0 260 18 9 6.7 3.7 | 16.5 61.7 260 14 7 9.5 5.2  
11000 15.5 59.9 260 17 9 6.8 3.7 | 17.3 63.1 260 14 7 9.6 5.3  
10750 16.0 60.8 260 16 8 6.9 3.8 | 18.0 64.4 260 13 7 10.3 5.7  
10500 16.5 61.7 255 15 8 5.1 2.8 | 18.8 65.8 260 13 7 11.0 6.0  
10250 16.8 62.2 255 14 7 3.1 1.7 | 19.6 67.3 260 13 7 10.8 6.0  
10000 17.0 62.6 245 13 7 3.5 1.9 | 20.4 68.7 260 13 6 11.4 6.3  
9750 17.2 63.0 240 12 6 2.4 1.3 | 21.3 70.3 255 12 6 9.5 5.2  
9500 17.5 63.5 230 11 5 9.8 5.4 | 22.0 71.6 255 12 6 15.1 8.3  
9250 18.8 65.8 225 9 5 25.4 13.9 | 23.8 74.8 255 11 6 32.6 17.9  
9000 20.2 68.4 220 8 4 1.1 0.6 | 26.0 78.8 255 10 5 17.6 9.7  
8750 M M M M M M M | M M M M M M M  
8500 M M M M M M M | M M M M M M M  
8250 M M M M M M M | M M M M M M M  
8000 M M M M M M M | M M M M M M M  
 
07/10/2025 AT 1500 MDT | 07/10/2025 AT 1800 MDT  
|  
CAPE... +980.9 LI... -3.0 | CAPE... +862.0 LI... -2.5  
CINH... -41.6 K INDEX... +31.4 | CINH... -23.2 K INDEX... +24.9  
|  
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 -63.9 -83.0 280 32 17 1.6 0.9 | -63.2 -81.8 285 32 17 2.0 1.1  
45000 -59.7 -75.5 280 51 26 4.7 2.6 | -59.0 -74.2 285 49 25 4.1 2.2  
40000 -52.2 -62.0 280 50 26 6.8 3.8 | -52.4 -62.3 285 45 23 6.5 3.6  
38000 -48.1 -54.6 280 44 23 6.8 3.8 | -48.4 -55.1 285 39 20 6.6 3.6  
36000 -44.0 -47.2 280 39 20 6.9 3.8 | -44.5 -48.1 280 34 17 6.5 3.6  
34000 -39.5 -39.1 280 37 19 7.5 4.1 | -39.8 -39.6 285 34 18 8.0 4.4  
32000 -34.4 -29.9 275 36 18 7.5 4.1 | -34.4 -29.9 285 36 18 7.9 4.3  
30000 -30.1 -22.2 275 34 17 7.3 4.0 | -30.1 -22.2 285 38 19 7.1 3.9  
29000 -27.9 -18.2 275 33 17 7.3 4.0 | -28.0 -18.4 285 38 20 7.1 3.9  
28000 -25.6 -14.1 275 33 17 8.6 4.7 | -25.8 -14.4 285 39 20 7.7 4.2  
27000 -23.1 -9.6 275 33 17 8.5 4.7 | -23.5 -10.3 285 36 18 7.7 4.2  
26000 -20.5 -4.9 275 33 17 8.5 4.7 | -21.2 -6.2 285 33 17 7.7 4.3  
25000 -18.0 -0.4 275 33 17 7.9 4.3 | -18.9 -2.0 285 30 15 7.6 4.2  
24000 -15.9 3.4 275 34 18 7.3 4.0 | -16.7 1.9 285 33 17 7.2 4.0  
23000 -13.8 7.2 270 36 19 7.4 4.1 | -14.5 5.9 285 36 19 7.3 4.0  
22000 -11.6 11.1 265 38 19 7.0 3.8 | -12.4 9.7 280 40 21 7.3 4.0  
21000 -9.8 14.4 270 35 18 6.6 3.6 | -10.2 13.6 285 37 19 7.4 4.1  
20000 -7.9 17.8 275 32 17 6.7 3.7 | -8.1 17.4 285 34 18 7.7 4.2  
19500 -7.0 19.4 275 31 16 6.7 3.7 | -7.1 19.2 285 33 17 7.9 4.3  
19000 -5.9 21.4 280 29 15 9.1 5.0 | -5.9 21.4 285 31 16 9.0 4.9  
18500 -4.6 23.7 285 27 14 8.9 4.9 | -4.6 23.7 290 29 15 9.0 4.9  
18000 -3.4 25.9 290 25 13 8.8 4.8 | -3.4 25.9 290 27 14 9.5 5.2  
17500 -2.1 28.2 290 23 12 8.7 4.8 | -1.9 28.6 290 25 13 9.9 5.4  
17000 -0.3 31.5 295 19 10 9.0 5.0 | 0.3 32.5 295 23 12 9.7 5.3  
16500 1.1 34.0 290 18 9 9.2 5.1 | 1.7 35.1 295 23 12 9.6 5.2  
16000 2.5 36.5 290 17 9 9.3 5.1 | 3.1 37.6 295 22 11 9.6 5.3  
15500 3.9 39.0 290 16 8 9.3 5.1 | 4.6 40.3 295 21 11 10.1 5.5  
15000 5.3 41.5 290 15 8 9.5 5.2 | 6.0 42.8 295 21 11 10.4 5.7  
14500 6.5 43.7 290 14 7 8.2 4.5 | 7.3 45.1 295 20 10 8.1 4.4  
14000 7.8 46.0 285 13 7 8.6 4.7 | 8.8 47.8 295 19 10 9.5 5.2  
13500 9.1 48.4 280 12 6 8.9 4.9 | 10.2 50.4 295 19 10 9.5 5.2  
13000 10.3 50.5 270 10 5 7.2 3.9 | 11.5 52.7 295 17 9 9.0 5.0  
12500 11.4 52.5 260 10 5 7.2 3.9 | 12.9 55.2 290 17 9 8.5 4.7  
12000 12.4 54.3 240 9 5 6.4 3.5 | 14.0 57.2 285 14 7 8.5 4.7  
11750 12.8 55.0 235 10 5 6.0 3.3 | 14.6 58.3 285 14 7 9.2 5.0  
11500 13.2 55.8 230 10 5 6.0 3.3 | 15.3 59.5 285 13 7 8.6 4.7  
11250 13.6 56.5 220 10 5 5.7 3.1 | 15.8 60.4 280 12 6 7.6 4.2  
11000 14.0 57.2 210 11 6 5.8 3.2 | 16.4 61.5 275 11 6 7.4 4.0  
10750 14.4 57.9 205 12 6 5.4 3.0 | 16.9 62.4 270 10 5 8.4 4.6  
10500 14.8 58.6 205 12 6 6.8 3.7 | 17.6 63.7 265 9 5 9.1 5.0  
10250 15.4 59.7 200 12 6 9.8 5.4 | 18.2 64.8 260 9 4 9.2 5.1  
10000 16.2 61.2 200 12 6 11.3 6.2 | 18.9 66.0 260 8 4 9.6 5.3  
9750 17.0 62.6 195 12 6 9.1 5.0 | 19.6 67.3 255 8 4 8.9 4.9  
9500 17.7 63.9 195 12 6 14.0 7.7 | 20.3 68.5 250 7 4 11.4 6.3  
9250 19.3 66.7 195 12 6 32.1 17.6 | 21.4 70.5 245 7 3 20.3 11.1  
9000 M M M M M M M | M M M M M M M  
8750 M M M M M M M | M M M M M M M  
8500 M M M M M M M | M M M M M M M  
8250 M M M M M M M | M M M M M M M  
8000 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 VILLA GROVE, COLORADO AT:  
 
NORTH LATITUDE: 38 DEG 16 MIN 03 SEC  
WEST LONGITUDE: 105 DEG 53 MIN 37 SEC  
ELEVATION: 7986 FEET (2434 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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