434
UXUS97 KPUB 041209
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO, COLORADO
0609 MDT FRIDAY, JULY 4, 2025
THIS FORECAST IS FOR FRIDAY, JULY 4, 2025:
IF THE TRIGGER TEMPERATURE OF 70.5 F/21.4 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 912 FT/MIN (4.6 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 17602 FT MSL (9978 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 80.0 F/27.1 C
TIME OF TRIGGER TEMPERATURE.................... 0845 MDT
TIME OF OVERDEVELOPMENT........................ NONE
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................. 14496 FT MSL (6872 FT AGL)
THERMAL SOARING OUTLOOK FOR SATURDAY 07/05..... EXCELLENT
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 05:39:20 / 20:28:20 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 49 MIN 0 SEC (889 MIN 0 SEC)
ALTITUDE OF SUN AT 13:03:50 MDT... 73.80 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 07/04/2025 AT 0600 MDT
FREEZING LEVEL.................. 15898 FT MSL (8274 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 14317 FT MSL (6693 FT AGL)
LIFTED CONDENSATION LEVEL....... 15722 FT MSL (8098 FT AGL)
LIFTED INDEX.................... -3.8
K INDEX......................... +30.0
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 -63.0 -81.4 220 30 15 3.2 1.7 M M M M M
45000 -56.9 -70.4 225 39 20 5.6 3.1 M M M M M
40000 -48.3 -54.9 215 44 23 6.3 3.5 M M M M M
38000 -44.5 -48.1 220 41 21 6.3 3.5 M M M M M
36000 -40.3 -40.5 220 38 19 6.3 3.4 M M M M M
34000 -36.6 -33.9 220 36 19 6.1 3.4 M M M M M
32000 -32.9 -27.2 215 35 18 5.9 3.2 M M M M M
30000 -28.5 -19.3 210 32 17 7.6 4.2 40.4 104.7 10.7 M M
29000 -26.2 -15.2 210 31 16 7.6 4.2 39.6 103.3 10.2 M M
28000 -23.9 -11.0 205 29 15 7.3 4.0 39.0 102.1 9.8 M M
27000 -21.8 -7.2 205 29 15 7.1 3.9 37.8 100.1 9.0 M M
26000 -19.7 -3.5 205 28 14 7.1 3.9 36.8 98.3 8.2 M M
25000 -17.6 0.3 205 27 14 7.1 3.9 36.0 96.7 7.6 M M
24000 -15.6 3.9 205 25 13 7.2 4.0 35.0 95.0 6.8 M M
23000 -13.5 7.7 205 22 12 7.3 4.0 34.1 93.3 6.0 M M
22000 -10.8 12.6 210 19 10 6.4 3.5 33.1 91.6 5.1 M M
21000 -9.3 15.3 215 18 9 5.4 3.0 31.5 88.7 3.7 M M
20000 -7.8 18.0 220 16 8 5.4 3.0 30.0 86.1 2.3 M M
19500 -7.0 19.4 225 16 8 5.3 2.9 29.3 84.8 1.7 M M
19000 -6.1 21.0 225 15 8 7.4 4.0 28.8 83.8 1.2 M M
18500 -5.1 22.8 230 15 8 7.2 3.9 28.3 83.0 0.8 M M
18000 -4.0 24.8 230 14 7 7.0 3.8 27.9 82.3 0.4 M M
17500 -3.1 26.4 230 13 7 6.8 3.7 27.4 81.3 -0.1 900 4.6
17000 -2.1 28.2 230 12 6 6.8 3.7 26.9 80.5 -0.6 856 4.3
16500 -1.1 30.0 230 11 6 6.6 3.6 26.4 79.5 -1.1 812 4.1
16000 -0.2 31.6 235 10 5 6.6 3.6 25.9 78.6 -1.6 768 3.9
15500 0.8 33.4 235 9 5 7.0 3.9 25.4 77.8 -2.1 724 3.7
15000 1.8 35.2 240 8 4 7.2 4.0 25.0 77.0 -2.6 679 3.4
14500 2.9 37.2 250 8 4 7.4 4.1 24.6 76.3 -3.0 633 3.2
14000 4.0 39.2 260 7 4 7.9 4.3 24.3 75.7 -3.4 585 3.0
13500 5.1 41.2 270 7 3 8.0 4.4 24.0 75.2 -3.7 537 2.7
13000 6.5 43.7 280 6 3 10.8 5.9 24.0 75.3 -3.8 479 2.4
12500 7.8 46.0 290 6 3 7.8 4.3 23.8 74.9 -4.0 427 2.2
12000 8.7 47.7 310 6 3 5.5 3.0 23.4 74.0 -4.5 383 1.9
11750 9.2 48.6 320 7 4 5.7 3.1 23.0 73.5 -4.8 363 1.8
11500 9.6 49.3 330 9 4 5.8 3.2 22.7 72.9 -5.1 343 1.7
11250 10.0 50.0 335 9 5 4.8 2.6 22.4 72.3 -5.5 324 1.6
11000 10.2 50.4 335 11 6 3.5 1.9 21.9 71.5 -5.9 308 1.6
10750 10.5 50.9 340 13 6 3.5 1.9 21.5 70.6 -6.4 293 1.5
10500 10.7 51.3 340 14 7 3.4 1.9 21.0 69.8 -6.9 279 1.4
10250 11.0 51.8 345 16 8 4.0 2.2 20.5 68.9 -7.4 264 1.3
10000 11.3 52.3 345 17 9 4.9 2.7 20.1 68.2 -7.8 246 1.3
9750 11.7 53.1 345 18 9 4.9 2.7 19.7 67.5 -8.2 228 1.2
9500 12.0 53.6 345 19 10 5.1 2.8 19.4 66.9 -8.6 210 1.1
9250 12.4 54.3 345 20 10 4.4 2.4 19.0 66.2 -9.0 192 1.0
9000 12.7 54.9 345 19 10 4.6 2.5 18.6 65.4 -9.5 176 0.9
8750 13.1 55.6 350 19 10 5.4 2.9 18.2 64.8 -9.9 158 0.8
8500 13.4 56.1 350 19 10 5.6 3.1 17.9 64.2 -10.3 139 0.7
8250 13.8 56.8 350 18 9 3.9 2.1 17.6 63.6 -10.6 121 0.6
8000 13.8 56.8 345 17 9 -0.6 -0.3 17.0 62.5 -11.3 112 0.6
7750 13.6 56.5 340 12 6 -2.8 -1.6 16.1 60.9 -12.3 110 0.6
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 * * * * * *
07/04/2025 AT 0900 MDT | 07/04/2025 AT 1200 MDT
|
CAPE... +448.1 LI... -2.8 | CAPE... +574.0 LI... -2.8
CINH... -12.8 K INDEX... +28.3 | CINH... 0.0 K INDEX... +24.1
|
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 -62.8 -81.0 235 21 11 3.0 1.7 | -63.4 -82.1 220 18 9 3.2 1.8
45000 -56.8 -70.2 230 32 16 5.7 3.1 | -57.1 -70.8 230 27 14 6.1 3.4
40000 -48.2 -54.8 225 47 24 6.1 3.3 | -47.9 -54.2 235 41 21 6.0 3.3
38000 -44.5 -48.1 225 42 22 6.1 3.4 | -43.8 -46.8 235 39 20 6.0 3.3
36000 -40.4 -40.7 230 37 19 6.3 3.4 | -40.2 -40.4 235 37 19 6.1 3.3
34000 -36.4 -33.5 230 36 19 6.6 3.6 | -36.5 -33.7 235 35 18 6.3 3.5
32000 -32.4 -26.3 225 35 18 6.6 3.6 | -32.7 -26.9 235 33 17 6.1 3.4
30000 -28.1 -18.6 220 33 17 7.2 4.0 | -28.1 -18.6 240 31 16 7.8 4.3
29000 -26.0 -14.8 220 32 16 7.3 4.0 | -25.8 -14.4 240 30 16 7.8 4.3
28000 -23.8 -10.8 220 31 16 6.9 3.8 | -23.5 -10.3 245 29 15 7.1 3.9
27000 -21.8 -7.2 215 29 15 6.6 3.6 | -21.4 -6.5 240 28 14 6.7 3.7
26000 -19.9 -3.8 215 27 14 6.7 3.7 | -19.4 -2.9 240 26 13 6.7 3.7
25000 -17.9 -0.2 215 25 13 6.8 3.7 | -17.4 0.7 240 24 12 6.9 3.8
24000 -16.1 3.0 215 23 12 6.1 3.3 | -15.7 3.7 240 23 12 5.4 3.0
23000 -14.3 6.3 215 21 11 6.1 3.4 | -14.1 6.6 240 22 11 5.5 3.0
22000 -12.1 10.2 220 19 10 6.2 3.4 | -12.1 10.2 235 21 11 6.4 3.5
21000 -10.3 13.5 225 17 9 6.2 3.4 | -10.1 13.8 240 20 10 6.8 3.7
20000 -8.5 16.7 230 15 8 6.3 3.5 | -8.0 17.6 245 19 10 6.8 3.7
19500 -7.6 18.3 230 15 8 6.3 3.5 | -7.0 19.4 245 19 10 6.7 3.7
19000 -6.7 19.9 235 14 7 6.3 3.5 | -6.1 21.0 250 18 9 6.1 3.3
18500 -5.8 21.6 240 13 7 6.4 3.5 | -5.3 22.5 250 17 9 6.3 3.4
18000 -4.9 23.2 245 13 6 6.6 3.6 | -4.4 24.1 255 16 8 6.7 3.7
17500 -4.0 24.8 255 12 6 6.8 3.7 | -3.5 25.7 255 16 8 7.0 3.8
17000 -3.0 26.6 260 11 6 6.8 3.8 | -2.5 27.5 260 15 8 7.1 3.9
16500 -2.0 28.4 265 11 6 7.5 4.1 | -1.6 29.1 260 15 8 6.6 3.6
16000 -0.9 30.4 265 11 6 7.4 4.1 | -0.6 30.9 260 15 8 6.7 3.7
15500 0.2 32.4 270 11 5 7.3 4.0 | 0.3 32.5 260 15 7 6.0 3.3
15000 1.2 34.2 270 11 5 7.3 4.0 | 1.1 34.0 265 14 7 6.0 3.3
14500 2.3 36.1 275 11 6 7.4 4.1 | 1.9 35.4 265 14 7 6.6 3.6
14000 3.3 37.9 275 10 5 7.5 4.1 | 2.9 37.2 270 13 7 7.2 3.9
13500 4.4 39.9 280 10 5 7.6 4.2 | 3.9 39.0 275 13 7 7.7 4.2
13000 5.5 41.9 285 10 5 8.0 4.4 | 5.0 41.0 275 10 5 9.3 5.1
12500 6.5 43.7 295 10 5 6.7 3.7 | 6.4 43.5 280 7 4 9.4 5.1
12000 7.3 45.1 300 11 6 5.2 2.9 | 7.7 45.9 285 6 3 8.6 4.7
11750 7.7 45.9 305 12 6 5.5 3.0 | 8.3 46.9 285 6 3 9.4 5.2
11500 8.2 46.8 310 13 7 6.9 3.8 | 9.1 48.4 290 5 3 11.4 6.3
11250 8.7 47.7 315 14 7 6.0 3.3 | 9.9 49.8 290 5 3 10.2 5.6
11000 9.0 48.2 320 14 7 4.7 2.6 | 10.6 51.1 290 5 3 8.8 4.8
10750 9.4 48.9 325 15 7 4.5 2.5 | 11.3 52.3 295 5 3 8.5 4.6
10500 9.7 49.5 330 15 8 6.7 3.7 | 12.0 53.6 295 5 2 11.3 6.2
10250 10.3 50.5 335 16 8 8.7 4.8 | 12.9 55.2 295 5 2 11.9 6.5
10000 10.9 51.6 335 15 8 7.7 4.2 | 13.6 56.5 300 4 2 9.3 5.1
9750 11.5 52.7 335 15 8 8.2 4.5 | 14.4 57.9 300 4 2 10.3 5.7
9500 12.1 53.8 340 15 8 7.5 4.1 | 15.1 59.2 300 4 2 8.9 4.9
9250 12.6 54.7 340 15 8 6.7 3.6 | 15.8 60.4 305 4 2 8.8 4.8
9000 13.1 55.6 340 14 7 8.9 4.9 | 16.5 61.7 305 4 2 11.0 6.0
8750 13.8 56.8 335 13 7 10.6 5.8 | 17.3 63.1 305 4 2 11.5 6.3
8500 14.5 58.1 335 12 6 10.0 5.5 | 18.2 64.8 310 4 2 11.1 6.1
8250 15.3 59.5 335 11 6 10.3 5.6 | 19.0 66.2 310 4 2 11.3 6.2
8000 16.1 61.0 335 11 5 15.0 8.2 | 20.0 68.0 315 3 2 18.0 9.9
7750 17.5 63.5 335 10 5 22.2 12.2 | 21.7 71.1 320 3 2 27.5 15.1
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
07/04/2025 AT 1500 MDT | 07/04/2025 AT 1800 MDT
|
CAPE... +568.5 LI... -2.9 | CAPE... +571.3 LI... -2.3
CINH... -1.0 K INDEX... +30.2 | CINH... -0.7 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 -63.1 -81.6 215 24 13 2.5 1.4 | -63.8 -82.8 220 29 15 2.5 1.4
45000 -57.5 -71.5 225 34 17 6.0 3.3 | -58.0 -72.4 225 41 21 6.3 3.5
40000 -48.0 -54.4 230 44 23 6.5 3.6 | -47.9 -54.2 235 48 25 6.6 3.6
38000 -44.1 -47.4 235 44 23 6.5 3.6 | -43.9 -47.0 240 47 24 6.6 3.6
36000 -40.2 -40.4 240 45 23 6.4 3.5 | -39.9 -39.8 245 46 24 6.1 3.4
34000 -36.4 -33.5 240 39 20 6.2 3.4 | -36.7 -34.1 245 40 21 5.4 3.0
32000 -32.7 -26.9 235 32 17 6.1 3.3 | -33.4 -28.1 245 35 18 5.2 2.9
30000 -28.8 -19.8 240 29 15 6.7 3.7 | -29.1 -20.4 240 30 15 7.4 4.1
29000 -26.7 -16.1 240 27 14 6.7 3.7 | -26.9 -16.4 240 27 14 7.4 4.1
28000 -24.7 -12.5 240 26 13 7.7 4.2 | -24.7 -12.5 245 25 13 7.1 3.9
27000 -22.2 -8.0 250 24 12 8.1 4.5 | -22.6 -8.7 250 24 12 7.1 3.9
26000 -19.8 -3.6 255 22 11 8.1 4.5 | -20.5 -4.9 255 23 12 7.1 3.9
25000 -17.4 0.7 265 21 11 8.2 4.5 | -18.4 -1.1 265 23 12 7.1 3.9
24000 -15.6 3.9 270 20 10 5.5 3.0 | -16.2 2.8 270 22 11 7.2 4.0
23000 -13.6 7.5 280 20 10 5.8 3.2 | -13.5 7.7 275 21 11 7.3 4.0
22000 -11.9 10.6 285 20 10 6.5 3.6 | -11.4 11.5 280 21 11 6.8 3.7
21000 -10.0 14.0 280 21 11 6.6 3.6 | -9.5 14.9 285 22 11 6.8 3.7
20000 -8.1 17.4 280 21 11 6.7 3.7 | -7.6 18.3 290 24 12 7.0 3.8
19500 -7.2 19.0 280 22 11 6.6 3.6 | -6.6 20.1 295 25 13 7.1 3.9
19000 -6.3 20.7 280 22 11 6.0 3.3 | -5.6 21.9 295 25 13 6.8 3.7
18500 -5.4 22.3 275 22 11 6.0 3.3 | -4.7 23.5 295 25 13 6.9 3.8
18000 -4.6 23.7 275 22 11 6.4 3.5 | -3.7 25.3 290 25 13 6.0 3.3
17500 -3.7 25.3 275 21 11 6.5 3.6 | -2.9 26.8 290 24 12 5.9 3.2
17000 -2.7 27.1 275 21 11 6.5 3.5 | -2.1 28.2 285 23 12 6.0 3.3
16500 -1.9 28.6 275 18 9 5.7 3.1 | -1.2 29.8 285 20 10 6.5 3.6
16000 -1.1 30.0 280 15 8 5.7 3.1 | -0.3 31.5 285 17 9 6.5 3.6
15500 -0.2 31.6 285 12 6 7.6 4.2 | 0.6 33.1 290 13 7 6.9 3.8
15000 0.9 33.6 290 9 5 7.7 4.2 | 1.5 34.7 295 8 4 6.9 3.8
14500 2.0 35.6 300 7 3 8.7 4.8 | 2.5 36.5 315 5 2 8.6 4.7
14000 3.3 37.9 310 5 3 9.4 5.2 | 3.9 39.0 325 4 2 9.5 5.2
13500 4.7 40.5 325 4 2 9.6 5.3 | 5.3 41.5 345 3 1 9.9 5.4
13000 6.1 43.0 325 4 2 9.9 5.4 | 6.8 44.2 350 3 1 10.2 5.6
12500 7.6 45.7 330 4 2 9.9 5.4 | 8.3 46.9 355 3 1 9.3 5.1
12000 9.0 48.2 330 4 2 8.6 4.7 | 9.6 49.3 355 3 1 8.7 4.8
11750 9.6 49.3 330 4 2 9.5 5.2 | 10.3 50.5 360 3 1 9.5 5.2
11500 10.4 50.7 330 4 2 11.1 6.1 | 11.0 51.8 360 3 1 10.9 6.0
11250 11.2 52.2 335 4 2 9.9 5.4 | 11.8 53.2 005 3 1 9.7 5.3
11000 11.9 53.4 335 4 2 8.9 4.9 | 12.5 54.5 005 3 1 8.8 4.8
10750 12.6 54.7 335 4 2 8.4 4.6 | 13.2 55.8 005 3 1 8.7 4.8
10500 13.2 55.8 335 4 2 11.3 6.2 | 13.8 56.8 010 3 1 10.1 5.6
10250 14.2 57.6 340 3 2 11.9 6.6 | 14.7 58.5 015 3 1 10.9 6.0
10000 14.9 58.8 340 3 2 9.2 5.1 | 15.4 59.7 020 3 1 9.8 5.4
9750 15.7 60.3 345 3 2 10.3 5.6 | 16.2 61.2 020 3 1 10.4 5.7
9500 16.4 61.5 345 3 2 8.8 4.8 | 16.9 62.4 025 3 1 9.1 5.0
9250 17.0 62.6 345 3 2 8.4 4.6 | 17.5 63.5 025 3 1 8.7 4.8
9000 17.7 63.9 350 3 2 10.1 5.6 | 18.3 64.9 030 3 1 10.2 5.6
8750 18.5 65.3 350 3 2 10.4 5.7 | 19.0 66.2 035 3 1 10.3 5.6
8500 19.2 66.6 355 3 2 10.3 5.7 | 19.8 67.6 035 3 1 10.2 5.6
8250 20.0 68.0 360 3 2 10.8 5.9 | 20.5 68.9 040 3 2 10.6 5.8
8000 20.9 69.6 360 3 2 13.2 7.2 | 21.4 70.5 040 3 2 13.0 7.1
7750 21.9 71.4 005 3 2 16.0 8.8 | 22.4 72.3 045 3 2 15.8 8.7
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) 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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