357
UXUS97 KPUB 061232
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO, COLORADO
0630 MDT WEDNESDAY, AUGUST 6, 2025
THIS FORECAST IS FOR WEDNESDAY, AUGUST 6, 2025:
IF THE TRIGGER TEMPERATURE OF 78.9 F/26.1 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1779 FT/MIN (9.0 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 25236 FT MSL (17630 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 92.0 F/33.8 C
TIME OF TRIGGER TEMPERATURE.................... 0930 MDT
TIME OF OVERDEVELOPMENT........................ 1600 MDT
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... NONE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 20070 FT MSL (12464 FT AGL)
THERMAL SOARING OUTLOOK FOR THURSDAY 08/07..... EXCELLENT
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 06:05:11 / 20:05:05 MDT
TOTAL POSSIBLE SUNSHINE........... 13 HR 59 MIN 55 SEC (839 MIN 55 SEC)
ALTITUDE OF SUN AT 13:05:08 MDT... 67.45 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 08/06/2025 AT 0600 MDT
FREEZING LEVEL.................. 17098 FT MSL (9492 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 26022 FT MSL (18416 FT AGL)
LIFTED CONDENSATION LEVEL....... 26071 FT MSL (18465 FT AGL)
LIFTED INDEX.................... +0.4
K INDEX......................... -7.1
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 -65.3 -85.5 260 26 14 0.6 0.3 M M M M M
45000 -61.9 -79.4 260 41 21 5.8 3.2 M M M M M
40000 -52.4 -62.3 270 45 23 6.8 3.7 M M M M M
38000 -48.3 -54.9 270 44 23 6.8 3.7 M M M M M
36000 -44.3 -47.7 270 43 22 7.3 4.0 M M M M M
34000 -39.7 -39.5 270 42 21 7.6 4.2 M M M M M
32000 -35.1 -31.2 275 40 21 8.0 4.4 M M M M M
30000 -30.6 -23.1 275 37 19 7.5 4.1 37.7 99.9 3.4 M M
29000 -28.3 -18.9 275 35 18 7.5 4.1 36.9 98.5 2.8 M M
28000 -26.1 -15.0 275 33 17 7.2 4.0 36.1 97.0 2.2 M M
27000 -24.0 -11.2 275 30 15 7.2 4.0 35.1 95.1 1.3 M M
26000 -21.8 -7.2 270 27 14 7.3 4.0 34.2 93.5 0.6 M M
25000 -19.6 -3.3 270 25 13 7.5 4.1 33.4 92.1 -0.1 1767 9.0
24000 -16.8 1.8 270 24 12 7.7 4.2 32.3 90.2 -1.0 1644 8.4
23000 -14.5 5.9 270 23 12 7.7 4.3 31.6 89.0 -1.6 1546 7.9
22000 -12.1 10.2 270 22 12 8.4 4.6 31.0 87.9 -2.2 1446 7.3
21000 -9.6 14.7 270 22 11 8.4 4.6 30.5 86.9 -2.7 1340 6.8
20000 -7.1 19.2 275 21 11 8.4 4.6 30.1 86.2 -3.0 1235 6.3
19500 -5.8 21.6 275 21 11 8.5 4.7 29.9 85.8 -3.2 1182 6.0
19000 -4.5 23.9 280 21 11 8.6 4.7 29.7 85.5 -3.4 1127 5.7
18500 -3.1 26.4 280 20 11 8.6 4.7 29.5 85.2 -3.5 1072 5.4
18000 -1.9 28.6 285 20 10 7.4 4.0 29.2 84.6 -3.8 1022 5.2
17500 -0.8 30.6 285 20 10 7.4 4.1 28.8 83.9 -4.2 974 4.9
17000 0.3 32.5 290 20 10 7.8 4.3 28.5 83.2 -4.6 925 4.7
16500 1.4 34.5 290 20 10 7.9 4.3 28.1 82.6 -4.9 876 4.4
16000 2.6 36.7 295 20 10 8.0 4.4 27.8 82.1 -5.2 826 4.2
15500 3.8 38.8 295 20 10 8.6 4.7 27.6 81.7 -5.5 774 3.9
15000 5.1 41.2 295 21 11 8.6 4.7 27.4 81.4 -5.7 722 3.7
14500 6.4 43.5 300 22 11 8.6 4.7 27.2 81.0 -6.0 669 3.4
14000 7.6 45.7 305 22 12 8.6 4.7 27.0 80.7 -6.2 616 3.1
13500 8.9 48.0 305 23 12 8.1 4.4 26.8 80.3 -6.4 564 2.9
13000 10.1 50.2 310 24 13 8.8 4.8 26.5 79.8 -6.7 513 2.6
12500 11.6 52.9 310 25 13 9.9 5.5 26.6 80.0 -6.7 452 2.3
12000 13.0 55.4 310 25 13 9.2 5.1 26.5 79.8 -6.8 396 2.0
11750 13.7 56.7 310 24 13 8.6 4.7 26.5 79.7 -6.9 368 1.9
11500 14.3 57.7 310 24 12 8.6 4.7 26.4 79.5 -7.0 342 1.7
11250 15.0 59.0 310 24 12 9.0 4.9 26.3 79.3 -7.1 315 1.6
11000 15.6 60.1 310 23 12 9.0 4.9 26.2 79.2 -7.2 287 1.5
10750 16.3 61.3 310 22 11 8.4 4.6 26.2 79.1 -7.3 260 1.3
10500 17.0 62.6 310 21 11 10.7 5.9 26.1 79.0 -7.3 232 1.2
10250 17.8 64.0 310 21 11 10.3 5.6 26.3 79.3 -7.2 199 1.0
10000 18.5 65.3 310 21 11 7.7 4.2 26.1 79.0 -7.4 173 0.9
9750 19.1 66.4 310 20 10 8.0 4.4 26.0 78.8 -7.5 147 0.7
9500 19.7 67.5 310 20 10 9.4 5.1 25.9 78.6 -7.6 121 0.6
9250 20.4 68.7 310 19 10 8.2 4.5 25.9 78.6 -7.6 92 0.5
9000 20.9 69.6 310 19 10 5.2 2.9 25.6 78.1 -7.9 70 0.4
8750 21.3 70.3 305 19 10 5.8 3.2 25.3 77.5 -8.3 50 0.3
8500 21.7 71.1 305 19 10 3.8 2.1 25.0 76.9 -8.6 31 0.2
8250 21.8 71.2 305 19 10 -0.1 -0.0 24.3 75.8 -9.3 21 0.1
8000 21.7 71.1 305 19 10 -3.4 -1.9 23.5 74.3 -10.2 18 0.1
7750 20.7 69.3 300 18 9 -28.1 -15.4 21.8 71.3 -11.9 39 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 * * * * * *
08/06/2025 AT 0900 MDT | 08/06/2025 AT 1200 MDT
|
CAPE... 0.0 LI... +2.1 | CAPE... +87.6 LI... +0.7
CINH... 0.0 K INDEX... +9.8 | CINH... -18.2 K INDEX... +17.2
|
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 -65.2 -85.4 265 29 15 -0.3 -0.2 | -64.6 -84.3 265 25 13 -0.1 -0.1
45000 -62.6 -80.7 260 47 24 5.9 3.3 | -62.0 -79.6 270 48 25 5.2 2.9
40000 -53.0 -63.4 265 46 24 6.9 3.8 | -53.8 -64.8 270 53 27 7.0 3.9
38000 -48.9 -56.0 265 46 23 6.9 3.8 | -49.6 -57.3 270 51 26 7.0 3.8
36000 -44.7 -48.5 270 44 23 7.3 4.0 | -45.4 -49.7 265 49 25 7.2 3.9
34000 -40.1 -40.2 270 41 21 7.6 4.2 | -40.2 -40.4 265 44 23 7.7 4.2
32000 -35.6 -32.1 270 37 19 8.1 4.4 | -35.6 -32.1 270 39 20 8.0 4.4
30000 -31.0 -23.8 270 33 17 7.6 4.2 | -31.1 -24.0 270 35 18 7.5 4.1
29000 -28.7 -19.7 275 31 16 7.6 4.2 | -28.9 -20.0 270 33 17 7.5 4.1
28000 -26.4 -15.5 275 29 15 7.2 3.9 | -26.7 -16.1 270 31 16 6.9 3.8
27000 -24.3 -11.7 270 27 14 7.3 4.0 | -24.6 -12.3 270 29 15 6.9 3.8
26000 -22.1 -7.8 265 26 14 7.3 4.0 | -22.6 -8.7 265 28 14 6.9 3.8
25000 -20.0 -4.0 265 25 13 7.5 4.1 | -20.5 -4.9 265 26 14 7.7 4.2
24000 -17.1 1.2 265 24 12 7.6 4.2 | -18.1 -0.6 270 25 13 7.9 4.3
23000 -14.8 5.4 260 23 12 7.6 4.2 | -15.8 3.6 270 23 12 7.9 4.3
22000 -12.5 9.5 260 21 11 8.1 4.4 | -13.5 7.7 270 22 11 8.0 4.4
21000 -10.1 13.8 270 20 10 8.1 4.5 | -10.5 13.1 275 19 10 8.1 4.4
20000 -7.7 18.1 275 19 10 8.1 4.5 | -8.1 17.4 280 18 9 8.0 4.4
19500 -6.5 20.3 275 18 9 8.2 4.5 | -6.9 19.6 280 17 9 8.5 4.7
19000 -5.3 22.5 280 18 9 8.2 4.5 | -5.6 21.9 285 17 9 8.5 4.6
18500 -4.0 24.8 285 17 9 8.2 4.5 | -4.4 24.1 290 17 9 8.5 4.7
18000 -2.9 26.8 290 18 9 7.7 4.2 | -3.1 26.4 290 17 9 8.6 4.7
17500 -1.7 28.9 295 18 9 7.8 4.3 | -1.9 28.6 295 17 9 8.7 4.8
17000 -0.6 30.9 300 19 10 8.0 4.4 | -0.6 30.9 295 17 9 8.5 4.7
16500 0.6 33.1 305 19 10 8.0 4.4 | 0.6 33.1 295 18 9 8.6 4.7
16000 1.8 35.2 310 20 10 8.2 4.5 | 1.9 35.4 300 18 9 8.7 4.8
15500 3.0 37.4 310 21 11 8.5 4.7 | 3.2 37.8 300 18 9 8.9 4.9
15000 4.3 39.7 315 21 11 8.5 4.7 | 4.5 40.1 300 17 9 9.0 4.9
14500 5.6 42.1 315 22 11 9.3 5.1 | 5.8 42.4 305 15 8 9.3 5.1
14000 7.0 44.6 315 21 11 9.4 5.1 | 7.2 45.0 305 14 7 9.3 5.1
13500 8.4 47.1 315 21 11 8.4 4.6 | 8.5 47.3 310 12 6 9.1 5.0
13000 9.6 49.3 315 21 11 9.4 5.2 | 9.9 49.8 310 10 5 10.4 5.7
12500 11.3 52.3 315 20 10 10.0 5.5 | 11.5 52.7 310 10 5 10.2 5.6
12000 12.7 54.9 315 20 10 9.3 5.1 | 13.0 55.4 310 9 5 9.9 5.5
11750 13.3 55.9 315 19 10 9.0 4.9 | 13.8 56.8 310 9 5 10.3 5.7
11500 14.0 57.2 315 19 10 8.7 4.8 | 14.5 58.1 310 9 5 9.9 5.5
11250 14.7 58.5 320 19 10 8.7 4.8 | 15.2 59.4 315 9 5 9.4 5.2
11000 15.4 59.7 320 18 10 8.7 4.8 | 16.0 60.8 315 9 4 9.2 5.1
10750 16.0 60.8 320 18 9 8.8 4.8 | 16.7 62.1 315 9 4 10.5 5.8
10500 16.7 62.1 325 18 9 9.6 5.3 | 17.5 63.5 315 8 4 11.9 6.5
10250 17.5 63.5 325 17 9 9.3 5.1 | 18.3 64.9 315 8 4 9.9 5.4
10000 18.1 64.6 325 17 9 8.6 4.7 | 19.0 66.2 315 8 4 8.7 4.8
9750 18.8 65.8 325 17 9 8.7 4.8 | 19.7 67.5 315 8 4 9.1 5.0
9500 19.4 66.9 330 16 8 8.8 4.8 | 20.4 68.7 315 8 4 10.7 5.9
9250 20.1 68.2 330 16 8 8.4 4.6 | 21.2 70.2 315 8 4 10.8 5.9
9000 20.7 69.3 330 16 8 8.0 4.4 | 22.0 71.6 315 8 4 9.7 5.3
8750 21.3 70.3 330 16 8 8.0 4.4 | 22.7 72.9 320 8 4 10.1 5.5
8500 21.8 71.2 325 15 8 7.5 4.1 | 23.5 74.3 320 7 4 10.6 5.8
8250 22.3 72.1 325 15 8 7.3 4.0 | 24.3 75.7 320 7 4 11.3 6.2
8000 22.8 73.0 320 15 7 5.1 2.8 | 25.1 77.2 320 7 4 8.4 4.6
7750 23.1 73.6 315 14 7 5.3 2.9 | 25.8 78.4 320 7 3 13.7 7.5
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
08/06/2025 AT 1500 MDT | 08/06/2025 AT 1800 MDT
|
CAPE... +206.7 LI... -0.1 | CAPE... +146.9 LI... -0.3
CINH... -19.6 K INDEX... +26.8 | CINH... -65.8 K INDEX... +29.0
|
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 -64.8 -84.6 275 28 14 0.9 0.5 | -65.2 -85.4 280 31 16 0.7 0.4
45000 -61.3 -78.3 280 48 24 5.1 2.8 | -62.0 -79.6 280 47 24 4.7 2.6
40000 -53.4 -64.1 275 57 29 6.5 3.6 | -54.1 -65.4 270 55 28 8.0 4.4
38000 -49.4 -56.9 270 54 28 6.5 3.6 | -49.3 -56.7 270 53 27 8.0 4.4
36000 -45.0 -49.0 265 51 26 8.2 4.5 | -44.5 -48.1 265 50 26 8.3 4.5
34000 -40.0 -40.0 265 48 25 8.3 4.5 | -38.8 -37.8 270 47 24 8.6 4.7
32000 -35.1 -31.2 265 44 23 8.3 4.6 | -33.6 -28.5 275 43 22 8.5 4.7
30000 -30.6 -23.1 265 40 20 7.5 4.1 | -28.8 -19.8 280 39 20 8.0 4.4
29000 -28.3 -18.9 260 37 19 7.5 4.1 | -26.4 -15.5 285 37 19 8.0 4.4
28000 -26.2 -15.2 260 35 18 7.0 3.8 | -24.3 -11.7 285 35 18 6.1 3.4
27000 -24.1 -11.4 260 33 17 7.0 3.9 | -22.4 -8.3 290 33 17 6.2 3.4
26000 -22.0 -7.6 260 32 16 7.0 3.9 | -20.6 -5.1 290 31 16 6.3 3.4
25000 -19.9 -3.8 260 30 15 7.2 4.0 | -18.7 -1.7 290 29 15 6.7 3.7
24000 -17.8 -0.0 265 29 15 7.4 4.0 | -16.7 1.9 290 27 14 6.9 3.8
23000 -15.7 3.7 270 28 14 7.4 4.1 | -14.7 5.5 285 24 12 7.0 3.9
22000 -13.5 7.7 275 27 14 8.5 4.7 | -12.7 9.1 285 21 11 8.4 4.6
21000 -10.4 13.3 280 21 11 8.6 4.7 | -9.6 14.7 280 16 8 8.6 4.7
20000 -7.9 17.8 280 17 9 8.8 4.9 | -7.1 19.2 280 12 6 8.8 4.8
19500 -6.7 19.9 285 14 7 7.5 4.1 | -6.0 21.2 275 11 6 6.8 3.7
19000 -5.6 21.9 285 12 6 7.6 4.1 | -5.0 23.0 275 10 5 6.8 3.7
18500 -4.5 23.9 290 9 5 8.1 4.5 | -4.0 24.8 275 9 5 7.1 3.9
18000 -3.1 26.4 290 8 4 9.4 5.1 | -2.9 26.8 270 8 4 8.0 4.4
17500 -1.7 28.9 290 7 4 9.3 5.1 | -1.7 28.9 265 7 4 7.9 4.3
17000 -0.3 31.5 290 6 3 9.9 5.4 | -0.5 31.1 260 7 4 8.5 4.7
16500 1.2 34.2 285 6 3 9.8 5.4 | 0.8 33.4 255 7 4 8.6 4.7
16000 2.7 36.9 285 5 2 9.7 5.3 | 2.0 35.6 250 7 4 8.9 4.9
15500 4.1 39.4 280 4 2 9.5 5.2 | 3.4 38.1 245 7 4 9.2 5.0
15000 5.5 41.9 270 4 2 9.5 5.2 | 4.8 40.6 240 8 4 9.2 5.1
14500 6.9 44.4 265 3 2 9.3 5.1 | 6.1 43.0 235 9 4 9.1 5.0
14000 8.3 46.9 250 3 1 9.4 5.2 | 7.5 45.5 230 10 5 9.2 5.1
13500 9.7 49.5 235 3 1 8.8 4.8 | 8.7 47.7 225 11 6 8.0 4.4
13000 11.0 51.8 215 3 1 10.1 5.5 | 9.9 49.8 220 13 7 8.4 4.6
12500 12.6 54.7 205 3 1 10.3 5.7 | 11.3 52.3 215 14 7 8.9 4.9
12000 14.1 57.4 195 4 2 10.5 5.8 | 12.6 54.7 215 16 8 9.0 4.9
11750 14.9 58.8 190 4 2 8.4 4.6 | 13.2 55.8 215 17 9 7.9 4.3
11500 15.4 59.7 185 4 2 8.2 4.5 | 13.8 56.8 210 17 9 8.0 4.4
11250 16.1 61.0 180 4 2 10.4 5.7 | 14.4 57.9 210 18 9 9.1 5.0
11000 16.9 62.4 180 4 2 9.6 5.3 | 15.1 59.2 210 18 9 8.8 4.8
10750 17.6 63.7 175 5 2 10.6 5.8 | 15.7 60.3 210 19 10 9.1 5.0
10500 18.5 65.3 175 5 3 11.4 6.3 | 16.4 61.5 210 20 10 10.2 5.6
10250 19.2 66.6 175 5 3 9.2 5.1 | 17.2 63.0 210 20 10 9.3 5.1
10000 19.9 67.8 175 6 3 8.1 4.4 | 17.8 64.0 210 20 11 8.1 4.5
9750 20.5 68.9 170 6 3 8.1 4.4 | 18.4 65.1 205 21 11 8.2 4.5
9500 21.1 70.0 170 6 3 11.0 6.0 | 19.0 66.2 205 21 11 10.1 5.5
9250 22.0 71.6 170 6 3 11.1 6.1 | 19.9 67.8 205 21 11 10.1 5.6
9000 22.7 72.9 170 7 3 8.5 4.7 | 20.5 68.9 205 21 11 8.2 4.5
8750 23.4 74.1 170 7 3 9.1 5.0 | 21.1 70.0 205 21 11 8.5 4.7
8500 24.1 75.4 165 7 4 10.6 5.8 | 21.8 71.2 200 21 11 9.8 5.4
8250 25.0 77.0 165 7 4 11.8 6.5 | 22.6 72.7 200 20 10 10.6 5.8
8000 25.7 78.3 165 7 4 8.1 4.5 | 23.3 73.9 200 19 10 8.9 4.9
7750 26.3 79.3 165 7 4 9.8 5.4 | 23.9 75.0 200 18 9 7.5 4.1
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) 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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