560
UXUS97 KPUB 051214
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO, COLORADO
0613 MDT TUESDAY, AUGUST 5, 2025
THIS FORECAST IS FOR TUESDAY, AUGUST 5, 2025:
IF THE TRIGGER TEMPERATURE OF 79.0 F/26.1 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1612 FT/MIN (8.2 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 25403 FT MSL (17779 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 91.0 F/33.2 C
TIME OF TRIGGER TEMPERATURE.................... 0945 MDT
TIME OF OVERDEVELOPMENT........................ 1200 MDT
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................. 19100 FT MSL (11476 FT AGL)
THERMAL SOARING OUTLOOK FOR WEDNESDAY 08/06.... EXCELLENT
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 06:04:17 / 20:06:13 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 1 MIN 56 SEC (841 MIN 56 SEC)
ALTITUDE OF SUN AT 13:05:15 MDT... 67.73 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 08/05/2025 AT 0600 MDT
FREEZING LEVEL.................. 17171 FT MSL (9547 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 26072 FT MSL (18448 FT AGL)
LIFTED CONDENSATION LEVEL....... 26159 FT MSL (18535 FT AGL)
LIFTED INDEX.................... +0.3
K INDEX......................... -16.6
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 -63.5 -82.3 245 32 16 -0.4 -0.2 M M M M M
45000 -61.5 -78.7 255 50 26 5.2 2.9 M M M M M
40000 -52.8 -63.0 260 56 29 7.4 4.1 M M M M M
38000 -48.4 -55.1 260 53 27 7.4 4.0 M M M M M
36000 -43.9 -47.0 265 49 25 7.2 4.0 M M M M M
34000 -39.8 -39.6 265 51 26 6.8 3.7 M M M M M
32000 -35.7 -32.3 270 53 27 7.2 3.9 M M M M M
30000 -31.3 -24.3 270 48 25 7.4 4.0 36.8 98.2 3.1 M M
29000 -29.1 -20.4 270 45 23 7.4 4.0 35.9 96.7 2.4 M M
28000 -26.9 -16.4 275 42 22 7.5 4.1 35.2 95.3 1.8 M M
27000 -24.7 -12.5 275 38 20 7.5 4.1 34.2 93.6 1.1 M M
26000 -22.4 -8.3 275 34 17 7.5 4.1 33.4 92.1 0.4 M M
25000 -20.2 -4.4 275 30 15 7.6 4.2 32.7 90.8 -0.2 1784 9.1
24000 -17.3 0.9 275 26 14 7.8 4.3 31.7 89.0 -1.0 1660 8.4
23000 -15.0 5.0 275 24 12 7.8 4.3 31.0 87.8 -1.6 1561 7.9
22000 -12.6 9.3 270 22 11 8.8 4.8 30.4 86.8 -2.1 1460 7.4
21000 -9.9 14.2 265 20 10 8.8 4.8 30.0 86.1 -2.5 1351 6.9
20000 -7.3 18.9 260 19 10 8.8 4.8 29.8 85.6 -2.8 1241 6.3
19500 -5.9 21.4 260 18 9 8.7 4.8 29.6 85.4 -2.9 1187 6.0
19000 -4.6 23.7 255 18 9 8.6 4.7 29.4 85.0 -3.1 1133 5.8
18500 -3.3 26.1 250 18 10 8.6 4.7 29.2 84.6 -3.2 1079 5.5
18000 -2.1 28.2 245 18 9 8.5 4.7 29.0 84.3 -3.4 1026 5.2
17500 -0.8 30.6 245 18 9 8.5 4.7 28.8 83.9 -3.7 973 4.9
17000 0.5 32.9 245 17 9 8.7 4.8 28.6 83.5 -3.9 920 4.7
16500 1.8 35.2 250 17 9 8.9 4.9 28.5 83.3 -4.0 865 4.4
16000 3.2 37.8 255 17 9 9.0 4.9 28.3 83.0 -4.2 810 4.1
15500 4.4 39.9 255 17 9 8.1 4.4 28.1 82.7 -4.4 758 3.8
15000 5.6 42.1 255 18 9 8.2 4.5 27.9 82.2 -4.7 707 3.6
14500 6.9 44.4 250 18 9 8.3 4.5 27.6 81.8 -4.9 655 3.3
14000 8.1 46.6 250 18 9 8.3 4.5 27.4 81.3 -5.2 604 3.1
13500 9.3 48.7 245 18 9 8.2 4.5 27.2 80.9 -5.4 552 2.8
13000 10.5 50.9 250 17 9 8.2 4.5 26.9 80.5 -5.7 500 2.5
12500 11.8 53.2 250 18 9 8.6 4.7 26.7 80.1 -6.0 448 2.3
12000 13.1 55.6 255 17 9 9.0 4.9 26.5 79.8 -6.1 394 2.0
11750 13.8 56.8 260 17 9 8.2 4.5 26.5 79.7 -6.2 367 1.9
11500 14.3 57.7 260 17 9 7.1 3.9 26.3 79.3 -6.4 343 1.7
11250 14.8 58.6 265 18 9 8.0 4.4 26.1 79.0 -6.6 319 1.6
11000 15.5 59.9 265 18 9 8.5 4.7 26.0 78.8 -6.8 293 1.5
10750 16.1 61.0 270 18 9 8.7 4.8 25.9 78.6 -6.9 267 1.4
10500 16.7 62.1 270 18 9 7.5 4.1 25.8 78.5 -7.0 241 1.2
10250 17.2 63.0 275 20 10 7.5 4.1 25.6 78.0 -7.3 219 1.1
10000 17.8 64.0 275 21 11 8.8 4.8 25.5 77.9 -7.4 193 1.0
9750 18.4 65.1 275 21 11 8.6 4.7 25.4 77.7 -7.6 167 0.8
9500 19.1 66.4 275 22 11 8.2 4.5 25.3 77.5 -7.7 141 0.7
9250 19.6 67.3 275 22 11 6.7 3.7 25.1 77.2 -7.9 118 0.6
9000 20.1 68.2 275 23 12 6.0 3.3 24.9 76.7 -8.2 97 0.5
8750 20.5 68.9 275 24 12 6.7 3.7 24.6 76.3 -8.5 75 0.4
8500 21.0 69.8 275 24 13 4.9 2.7 24.3 75.8 -8.7 53 0.3
8250 21.1 70.0 275 25 13 -2.3 -1.2 23.7 74.7 -9.4 42 0.2
8000 20.3 68.5 275 23 12 -24.8 -13.6 22.1 71.8 -11.0 61 0.3
7750 17.2 63.0 270 16 8 -51.9 -28.5 18.4 65.1 -14.8 144 0.7
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 * * * * * *
08/05/2025 AT 0900 MDT | 08/05/2025 AT 1200 MDT
|
CAPE... 0.0 LI... +1.6 | CAPE... +7.4 LI... +1.6
CINH... 0.0 K INDEX... -9.0 | CINH... -53.7 K INDEX... +1.5
|
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 -64.7 -84.5 250 37 19 0.4 0.2 | -63.9 -83.0 260 42 22 -0.0 -0.0
45000 -62.0 -79.6 260 55 28 5.0 2.8 | -61.9 -79.4 260 65 34 4.5 2.5
40000 -53.4 -64.1 260 60 31 7.8 4.3 | -54.1 -65.4 255 67 35 7.6 4.1
38000 -48.7 -55.7 260 58 30 7.8 4.3 | -49.6 -57.3 260 65 33 7.5 4.1
36000 -44.0 -47.2 265 57 30 7.5 4.1 | -45.1 -49.2 265 63 32 7.4 4.1
34000 -39.8 -39.6 265 54 28 7.1 3.9 | -40.7 -41.3 265 57 29 7.3 4.0
32000 -35.5 -31.9 270 52 27 7.7 4.2 | -36.4 -33.5 265 51 26 7.5 4.1
30000 -31.5 -24.7 275 45 23 6.7 3.7 | -32.3 -26.1 265 43 22 6.7 3.7
29000 -29.5 -21.1 275 41 21 6.7 3.7 | -30.3 -22.5 265 39 20 6.7 3.7
28000 -27.5 -17.5 275 38 19 7.7 4.2 | -28.3 -18.9 265 35 18 8.1 4.5
27000 -25.1 -13.2 275 35 18 7.8 4.3 | -25.8 -14.4 265 33 17 8.2 4.5
26000 -22.8 -9.0 270 33 17 7.8 4.3 | -23.4 -10.1 265 31 16 8.2 4.5
25000 -20.5 -4.9 270 31 16 7.9 4.3 | -20.9 -5.6 265 29 15 8.2 4.5
24000 -18.1 -0.6 270 29 15 8.0 4.4 | -17.9 -0.2 260 27 14 8.2 4.5
23000 -15.1 4.8 265 26 14 8.0 4.4 | -15.4 4.3 260 25 13 8.3 4.5
22000 -12.6 9.3 265 25 13 8.8 4.8 | -12.9 8.8 260 23 12 8.6 4.7
21000 -10.0 14.0 260 24 12 8.7 4.8 | -10.3 13.5 255 21 11 8.6 4.7
20000 -7.4 18.7 255 24 12 8.7 4.8 | -7.6 18.3 250 19 10 8.7 4.8
19500 -6.1 21.0 250 24 12 8.4 4.6 | -6.3 20.7 250 18 9 8.5 4.7
19000 -4.8 23.4 255 25 13 8.3 4.5 | -5.1 22.8 250 18 9 8.4 4.6
18500 -3.6 25.5 260 27 14 8.2 4.5 | -3.8 25.2 245 17 9 8.4 4.6
18000 -2.3 27.9 260 26 13 9.7 5.3 | -2.5 27.5 240 16 8 8.9 4.9
17500 -0.8 30.6 255 21 11 9.5 5.2 | -1.2 29.8 230 15 8 8.9 4.9
17000 0.6 33.1 245 18 9 8.9 4.9 | 0.2 32.4 220 14 7 8.4 4.6
16500 1.9 35.4 250 17 9 8.4 4.6 | 1.4 34.5 240 15 8 8.2 4.5
16000 3.1 37.6 255 16 8 8.3 4.5 | 2.6 36.7 260 18 9 8.2 4.5
15500 4.2 39.6 260 16 8 7.3 4.0 | 3.8 38.8 265 20 10 8.6 4.7
15000 5.3 41.5 265 17 9 7.3 4.0 | 5.1 41.2 270 22 11 8.6 4.7
14500 6.4 43.5 275 16 8 8.6 4.7 | 6.4 43.5 270 23 12 8.6 4.7
14000 7.7 45.9 280 15 8 8.7 4.8 | 7.6 45.7 270 23 12 8.7 4.8
13500 9.0 48.2 285 14 7 8.9 4.9 | 8.8 47.8 275 22 12 9.0 5.0
13000 10.4 50.7 280 14 7 9.0 5.0 | 10.1 50.2 275 19 10 9.7 5.3
12500 11.8 53.2 285 11 6 9.5 5.2 | 11.7 53.1 275 18 10 10.7 5.9
12000 13.2 55.8 290 10 5 9.9 5.4 | 13.3 55.9 275 18 9 10.9 6.0
11750 13.9 57.0 290 9 5 8.6 4.7 | 14.1 57.4 275 18 9 8.6 4.7
11500 14.5 58.1 290 9 4 7.3 4.0 | 14.6 58.3 275 18 9 7.9 4.3
11250 15.1 59.2 290 10 5 8.6 4.7 | 15.3 59.5 275 18 9 10.3 5.7
11000 15.7 60.3 290 11 6 8.8 4.8 | 16.1 61.0 275 18 9 10.3 5.6
10750 16.4 61.5 285 13 7 9.3 5.1 | 16.9 62.4 275 17 9 10.4 5.7
10500 17.0 62.6 285 14 7 7.4 4.1 | 17.7 63.9 275 17 9 9.8 5.4
10250 17.4 63.3 285 16 8 6.5 3.5 | 18.4 65.1 275 17 9 9.6 5.3
10000 18.0 64.4 285 19 10 7.7 4.2 | 19.1 66.4 275 17 9 10.0 5.5
9750 18.5 65.3 285 21 11 7.7 4.2 | 19.9 67.8 275 16 8 10.2 5.6
9500 19.0 66.2 280 24 12 6.5 3.6 | 20.6 69.1 275 16 8 9.3 5.1
9250 19.4 66.9 285 27 14 6.0 3.3 | 21.3 70.3 275 16 8 9.6 5.3
9000 20.0 68.0 285 28 15 7.1 3.9 | 22.0 71.6 275 16 8 10.8 5.9
8750 20.5 68.9 285 29 15 7.6 4.2 | 22.8 73.0 275 15 8 10.7 5.9
8500 21.1 70.0 285 31 16 5.4 3.0 | 23.6 74.5 275 15 8 10.3 5.7
8250 21.3 70.3 285 29 15 2.7 1.5 | 24.4 75.9 275 15 8 11.0 6.0
8000 21.6 70.9 280 25 13 7.2 3.9 | 25.4 77.7 275 14 7 17.5 9.6
7750 22.3 72.1 280 18 9 13.3 7.3 | 27.0 80.6 275 13 6 25.4 13.9
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
08/05/2025 AT 1500 MDT | 08/05/2025 AT 1800 MDT
|
CAPE... +46.3 LI... -0.7 | CAPE... +41.4 LI... -0.5
CINH... -5.4 K INDEX... +11.6 | CINH... -19.2 K INDEX... +8.2
|
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 -63.3 -81.9 265 42 22 0.2 0.1 | -63.0 -81.4 275 32 17 0.5 0.3
45000 -61.4 -78.5 270 68 35 3.9 2.2 | -61.0 -77.8 280 56 29 3.1 1.7
40000 -54.3 -65.7 265 71 36 7.8 4.3 | -54.9 -66.8 275 68 35 8.4 4.6
38000 -49.7 -57.5 265 67 34 7.7 4.2 | -49.8 -57.6 275 65 33 8.4 4.6
36000 -45.0 -49.0 265 63 33 7.6 4.2 | -44.8 -48.6 270 61 32 7.9 4.3
34000 -40.6 -41.1 265 57 30 7.4 4.1 | -40.6 -41.1 270 56 29 6.9 3.8
32000 -36.1 -33.0 270 52 27 7.8 4.3 | -36.4 -33.5 270 50 26 7.5 4.1
30000 -32.1 -25.8 265 45 23 6.5 3.6 | -32.0 -25.6 270 46 23 7.5 4.1
29000 -30.2 -22.4 265 42 22 6.5 3.6 | -29.8 -21.6 270 43 22 7.5 4.1
28000 -28.1 -18.6 260 39 20 7.4 4.0 | -27.6 -17.7 270 40 21 6.6 3.6
27000 -25.9 -14.6 260 36 18 7.4 4.1 | -25.6 -14.1 270 36 19 6.5 3.6
26000 -23.7 -10.7 260 33 17 7.4 4.1 | -23.6 -10.5 270 32 17 6.5 3.6
25000 -21.5 -6.7 265 29 15 7.7 4.2 | -21.1 -6.0 265 27 14 8.4 4.6
24000 -18.5 -1.3 260 27 14 8.2 4.5 | -18.6 -1.5 265 23 12 8.4 4.6
23000 -16.0 3.2 260 25 13 8.2 4.5 | -16.1 3.0 265 19 10 8.4 4.6
22000 -13.5 7.7 260 22 12 9.2 5.1 | -13.6 7.5 265 15 8 9.6 5.3
21000 -10.8 12.6 260 19 10 9.1 5.0 | -10.7 12.7 270 13 7 9.5 5.2
20000 -8.1 17.4 265 16 8 9.1 5.0 | -7.9 17.8 275 12 6 9.5 5.2
19500 -6.7 19.9 265 15 8 9.2 5.0 | -6.4 20.5 275 11 6 9.7 5.3
19000 -5.3 22.5 270 13 7 9.3 5.1 | -5.0 23.0 275 10 5 9.7 5.3
18500 -4.0 24.8 270 12 6 9.3 5.1 | -3.5 25.7 280 10 5 9.7 5.3
18000 -2.6 27.3 275 11 6 9.6 5.3 | -2.1 28.2 280 10 5 9.5 5.2
17500 -1.2 29.8 275 11 6 9.6 5.3 | -0.7 30.7 280 9 5 9.5 5.2
17000 0.3 32.5 275 11 6 9.7 5.3 | 0.8 33.4 280 9 5 9.5 5.2
16500 1.7 35.1 275 11 6 9.8 5.4 | 2.2 36.0 280 9 5 9.5 5.2
16000 3.2 37.8 275 11 6 9.8 5.4 | 3.6 38.5 285 8 4 9.5 5.2
15500 4.7 40.5 275 10 5 9.8 5.4 | 5.0 41.0 285 8 4 9.5 5.2
15000 6.1 43.0 275 10 5 9.8 5.4 | 6.5 43.7 285 8 4 9.5 5.2
14500 7.6 45.7 275 10 5 9.8 5.4 | 7.9 46.2 285 7 4 9.8 5.4
14000 9.1 48.4 275 10 5 9.8 5.4 | 9.4 48.9 285 7 4 9.8 5.4
13500 10.5 50.9 275 9 5 9.8 5.4 | 10.8 51.4 280 7 3 9.6 5.2
13000 12.0 53.6 275 9 5 9.9 5.4 | 12.2 54.0 280 6 3 9.6 5.3
12500 13.5 56.3 275 9 5 10.5 5.8 | 13.7 56.7 280 6 3 10.1 5.5
12000 15.1 59.2 275 8 4 11.4 6.2 | 15.3 59.5 275 5 3 10.8 5.9
11750 15.9 60.6 275 8 4 8.6 4.7 | 16.0 60.8 275 5 3 8.6 4.7
11500 16.4 61.5 275 8 4 7.7 4.2 | 16.6 61.9 275 5 3 8.0 4.4
11250 17.2 63.0 275 8 4 10.5 5.8 | 17.3 63.1 270 5 2 10.2 5.6
11000 17.9 64.2 275 8 4 10.2 5.6 | 18.0 64.4 265 4 2 9.9 5.4
10750 18.7 65.7 275 8 4 10.5 5.8 | 18.8 65.8 260 4 2 10.5 5.8
10500 19.5 67.1 275 8 4 9.5 5.2 | 19.5 67.1 255 4 2 8.2 4.5
10250 20.2 68.4 275 8 4 9.3 5.1 | 20.0 68.0 255 4 2 7.8 4.3
10000 20.9 69.6 275 7 4 10.0 5.5 | 20.7 69.3 245 4 2 9.8 5.4
9750 21.6 70.9 275 7 4 10.2 5.6 | 21.5 70.7 235 3 2 9.7 5.3
9500 22.4 72.3 275 7 4 8.6 4.7 | 22.2 72.0 225 3 2 8.3 4.5
9250 23.0 73.4 275 7 4 9.3 5.1 | 22.7 72.9 210 4 2 8.6 4.7
9000 23.8 74.8 275 7 4 11.4 6.3 | 23.5 74.3 205 4 2 10.5 5.7
8750 24.6 76.3 275 7 3 11.1 6.1 | 24.2 75.6 200 4 2 10.2 5.6
8500 25.5 77.9 275 6 3 10.5 5.8 | 25.0 77.0 195 4 2 9.9 5.4
8250 26.2 79.2 275 6 3 10.9 6.0 | 25.7 78.3 190 5 2 9.5 5.2
8000 27.2 81.0 275 6 3 17.0 9.4 | 26.4 79.5 190 5 2 10.5 5.8
7750 28.7 83.7 270 5 3 24.1 13.2 | 27.2 81.0 190 4 2 11.7 6.4
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) 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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