071
UXUS97 KPUB 281205
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO, COLORADO
0605 MDT MONDAY, APRIL 28, 2025
THIS FORECAST IS FOR THE AIR FORCE ACADEMY FOR MONDAY, APRIL 28, 2025:
IF THE TRIGGER TEMPERATURE OF 47.6 F/8.7 C IS REACHED...THEN
THERMAL SOARING INDEX....................... GOOD
MAXIMUM RATE OF LIFT........................ 1123 FT/MIN (5.7 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 21739 FT MSL (14107 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 63.0 F/17.7 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............ BETWEEN 20 MPH AND 30 MPH
HEIGHT OF THE -3 THERMAL INDEX................. 18825 FT MSL (11193 FT AGL)
THERMAL SOARING OUTLOOK FOR TUESDAY 04/29...... GOOD
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 06:04:09 / 19:49:15 MDT
TOTAL POSSIBLE SUNSHINE........... 13 HR 45 MIN 6 SEC (825 MIN 6 SEC)
ALTITUDE OF SUN AT 12:56:42 MDT... 65.42 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 04/28/2025 AT 0600 MDT
FREEZING LEVEL.................. 9958 FT MSL (2326 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 19731 FT MSL (12099 FT AGL)
LIFTED CONDENSATION LEVEL....... 20853 FT MSL (13221 FT AGL)
LIFTED INDEX.................... +2.5
K INDEX......................... -27.4
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 -54.4 -65.9 225 38 19 0.4 0.2 M M M M M
45000 -53.8 -64.8 230 61 32 -0.7 -0.4 M M M M M
40000 -56.3 -69.3 220 71 36 -1.6 -0.9 M M M M M
38000 -55.0 -67.0 220 77 40 5.3 2.9 M M M M M
36000 -51.9 -61.4 225 84 43 5.3 2.9 M M M M M
34000 -48.4 -55.1 225 90 47 7.8 4.3 M M M M M
32000 -43.8 -46.8 225 96 49 7.7 4.2 M M M M M
30000 -39.4 -38.9 225 99 51 4.9 2.7 30.6 87.2 10.3 M M
29000 -37.9 -36.2 230 95 49 5.2 2.8 28.7 83.7 9.0 M M
28000 -36.3 -33.3 230 92 47 5.2 2.8 27.0 80.6 7.7 M M
27000 -34.8 -30.6 230 88 46 5.2 2.9 25.4 77.7 6.5 M M
26000 -33.3 -27.9 230 85 44 4.8 2.6 23.5 74.3 5.1 M M
25000 -31.9 -25.4 235 81 42 4.8 2.6 21.7 71.0 3.6 M M
24000 -30.5 -22.9 235 77 40 4.7 2.6 19.9 67.9 2.3 M M
23000 -28.1 -18.6 235 75 39 7.0 3.8 18.4 65.1 1.0 M M
22000 -26.0 -14.8 240 74 38 7.0 3.8 17.4 63.3 0.1 M M
21000 -23.9 -11.0 240 73 38 6.5 3.6 16.5 61.7 -0.6 1246 6.3
20000 -22.1 -7.8 240 65 34 6.2 3.4 15.2 59.3 -1.8 1161 5.9
19500 -21.1 -6.0 240 61 32 6.2 3.4 14.6 58.2 -2.3 1118 5.7
19000 -20.2 -4.4 240 57 29 6.1 3.4 14.0 57.1 -2.9 1076 5.5
18500 -19.3 -2.7 240 53 27 5.7 3.1 13.4 56.2 -3.4 1033 5.2
18000 -18.5 -1.3 240 51 26 4.9 2.7 12.6 54.7 -4.1 996 5.1
17500 -17.8 -0.0 245 48 25 4.6 2.5 11.8 53.2 -4.9 959 4.9
17000 -16.9 1.6 245 45 23 7.9 4.3 11.2 52.2 -5.5 917 4.7
16500 -15.8 3.6 245 42 22 7.6 4.1 10.8 51.5 -5.8 868 4.4
16000 -14.6 5.7 245 38 20 8.0 4.4 10.5 50.9 -6.2 820 4.2
15500 -13.4 7.9 245 37 19 8.2 4.5 10.2 50.4 -6.5 768 3.9
15000 -12.2 10.0 245 36 19 8.6 4.7 10.0 50.0 -6.7 717 3.6
14500 -10.8 12.6 245 32 17 9.3 5.1 9.9 49.8 -6.9 661 3.4
14000 -9.4 15.1 240 28 15 9.3 5.1 9.8 49.7 -7.0 604 3.1
13500 -8.0 17.6 240 27 14 9.3 5.1 9.7 49.5 -7.1 548 2.8
13000 -6.6 20.1 240 26 13 10.1 5.6 9.7 49.4 -7.2 491 2.5
12500 -5.1 22.8 240 26 13 7.8 4.3 9.7 49.5 -7.2 431 2.2
12000 -4.1 24.6 240 26 13 6.8 3.7 9.2 48.6 -7.7 386 2.0
11750 -3.6 25.5 240 26 14 6.3 3.4 9.0 48.2 -7.9 364 1.9
11500 -3.2 26.2 245 27 14 5.9 3.2 8.7 47.6 -8.3 344 1.7
11250 -2.8 27.0 245 28 14 5.9 3.3 8.4 47.1 -8.6 323 1.6
11000 -2.3 27.9 250 28 15 5.8 3.2 8.1 46.6 -8.9 303 1.5
10750 -1.9 28.6 250 29 15 6.7 3.7 7.8 46.1 -9.2 282 1.4
10500 -1.4 29.5 255 31 16 7.4 4.1 7.6 45.7 -9.5 259 1.3
10250 -0.8 30.6 255 32 17 7.5 4.1 7.4 45.4 -9.7 236 1.2
10000 -0.3 31.5 255 33 17 7.7 4.2 7.3 45.1 -9.9 213 1.1
9750 0.2 32.4 255 32 17 7.6 4.1 7.1 44.8 -10.1 189 1.0
9500 0.8 33.4 260 31 16 7.7 4.2 6.9 44.5 -10.4 166 0.8
9250 1.3 34.3 260 30 16 7.3 4.0 6.8 44.2 -10.6 142 0.7
9000 1.8 35.2 260 29 15 5.9 3.2 6.5 43.7 -10.9 121 0.6
8750 2.1 35.8 260 27 14 5.3 2.9 6.2 43.1 -11.3 103 0.5
8500 2.5 36.5 265 25 13 4.7 2.6 5.8 42.5 -11.7 85 0.4
8250 2.8 37.0 265 22 11 6.7 3.7 5.5 41.9 -12.1 67 0.3
8000 2.9 37.2 270 13 7 -11.6 -6.3 4.1 39.5 -13.6 51 0.3
7750 2.3 36.1 275 7 4 7.8 4.3 2.9 37.2 -14.9 60 0.3
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 * * * * * *
04/28/2025 AT 0900 MDT | 04/28/2025 AT 1200 MDT
|
CAPE... 0.0 LI... +3.1 | CAPE... +46.1 LI... +0.4
CINH... 0.0 K INDEX... -26.3 | CINH... 0.0 K INDEX... -0.5
|
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 -54.5 -66.1 230 38 20 0.9 0.5 | -55.0 -67.0 225 29 15 2.6 1.4
45000 -53.1 -63.6 235 60 31 -0.1 -0.0 | -51.1 -60.0 240 41 21 -0.1 -0.0
40000 -54.6 -66.3 225 70 36 -1.0 -0.5 | -53.5 -64.3 225 67 34 -1.5 -0.8
38000 -53.6 -64.5 220 76 39 3.8 2.1 | -52.6 -62.7 225 73 38 3.7 2.0
36000 -51.4 -60.5 225 82 42 3.8 2.1 | -50.4 -58.7 225 78 40 3.7 2.0
34000 -48.8 -55.8 225 88 45 6.7 3.7 | -48.1 -54.6 230 82 42 5.0 2.8
32000 -45.0 -49.0 230 91 47 6.4 3.5 | -45.1 -49.2 230 84 43 4.9 2.7
30000 -41.1 -42.0 230 94 48 6.0 3.3 | -42.0 -43.6 230 86 44 7.1 3.9
29000 -39.3 -38.7 230 92 47 6.0 3.3 | -39.9 -39.8 230 85 44 6.9 3.8
28000 -37.5 -35.5 230 90 46 6.0 3.3 | -37.8 -36.0 230 84 43 6.9 3.8
27000 -35.7 -32.3 230 88 45 6.2 3.4 | -35.8 -32.4 230 83 43 7.1 3.9
26000 -34.1 -29.4 230 86 44 5.0 2.8 | -34.0 -29.2 230 81 42 5.5 3.0
25000 -32.6 -26.7 230 83 43 5.1 2.8 | -32.3 -26.1 230 78 40 5.5 3.0
24000 -31.1 -24.0 230 80 41 5.0 2.7 | -30.7 -23.3 235 75 39 5.5 3.0
23000 -28.6 -19.5 230 76 39 7.2 3.9 | -28.3 -18.9 235 72 37 6.8 3.7
22000 -26.5 -15.7 235 74 38 7.2 3.9 | -26.2 -15.2 235 70 36 6.8 3.7
21000 -24.3 -11.7 235 71 36 6.8 3.7 | -24.2 -11.6 240 67 35 5.5 3.0
20000 -22.4 -8.3 235 63 32 6.6 3.6 | -22.8 -9.0 240 56 29 4.8 2.6
19500 -21.4 -6.5 240 59 30 6.6 3.6 | -22.0 -7.6 240 50 26 4.8 2.6
19000 -20.4 -4.7 240 55 28 6.6 3.6 | -21.3 -6.3 245 44 23 4.8 2.6
18500 -19.4 -2.9 240 51 26 6.3 3.4 | -20.6 -5.1 245 38 20 4.7 2.6
18000 -18.5 -1.3 245 45 23 5.9 3.2 | -19.9 -3.8 245 32 17 4.6 2.5
17500 -17.6 0.3 245 39 20 5.7 3.1 | -19.2 -2.6 245 26 13 4.4 2.4
17000 -16.6 2.1 250 35 18 7.6 4.2 | -18.3 -0.9 245 21 11 8.6 4.7
16500 -15.5 4.1 250 31 16 7.4 4.1 | -17.1 1.2 245 19 10 8.4 4.6
16000 -14.4 6.1 255 28 14 7.1 3.9 | -15.9 3.4 250 16 8 9.0 5.0
15500 -13.4 7.9 255 26 14 7.0 3.8 | -14.5 5.9 260 15 7 9.2 5.1
15000 -12.4 9.7 260 25 13 7.7 4.2 | -13.2 8.2 270 13 7 9.4 5.2
14500 -11.1 12.0 255 24 12 8.7 4.8 | -11.8 10.8 270 13 7 9.6 5.2
14000 -9.8 14.4 255 23 12 8.7 4.8 | -10.3 13.5 270 13 7 9.7 5.3
13500 -8.5 16.7 250 21 11 8.9 4.9 | -8.8 16.2 275 13 7 10.3 5.6
13000 -7.1 19.2 245 19 10 9.8 5.4 | -7.3 18.9 275 13 6 12.1 6.6
12500 -5.6 21.9 250 18 9 7.6 4.2 | -5.6 21.9 275 12 6 8.8 4.8
12000 -4.7 23.5 260 17 9 6.4 3.5 | -4.3 24.3 275 12 6 8.7 4.7
11750 -4.2 24.4 265 17 9 6.6 3.6 | -3.6 25.5 275 12 6 10.0 5.5
11500 -3.7 25.3 270 18 9 6.0 3.3 | -2.8 27.0 275 12 6 10.0 5.5
11250 -3.4 25.9 275 20 10 5.1 2.8 | -2.1 28.2 280 12 6 9.2 5.0
11000 -3.0 26.6 275 22 11 5.1 2.8 | -1.4 29.5 280 12 6 9.3 5.1
10750 -2.7 27.1 280 24 12 4.6 2.5 | -0.7 30.7 280 12 6 9.1 5.0
10500 -2.4 27.7 280 25 13 4.0 2.2 | -0.1 31.8 280 12 6 9.0 4.9
10250 -2.1 28.2 280 26 13 5.6 3.1 | 0.7 33.3 280 11 6 10.6 5.8
10000 -1.6 29.1 285 25 13 7.3 4.0 | 1.5 34.7 280 11 6 11.3 6.2
9750 -1.1 30.0 285 24 12 8.5 4.7 | 2.3 36.1 280 11 6 10.1 5.5
9500 -0.5 31.1 285 22 12 9.2 5.1 | 3.0 37.4 280 11 6 9.7 5.3
9250 0.2 32.4 285 21 11 9.6 5.2 | 3.8 38.8 280 11 6 9.9 5.5
9000 1.0 33.8 285 20 10 10.7 5.9 | 4.5 40.1 280 11 6 10.5 5.7
8750 1.8 35.2 285 19 10 10.7 5.9 | 5.3 41.5 280 11 6 10.6 5.8
8500 2.6 36.7 285 19 10 11.1 6.1 | 6.1 43.0 285 11 5 11.3 6.2
8250 3.4 38.1 285 18 9 9.0 5.0 | 6.9 44.4 285 10 5 8.7 4.8
8000 4.1 39.4 285 17 9 13.6 7.5 | 7.7 45.9 285 10 5 16.5 9.1
7750 5.6 42.1 285 15 8 27.5 15.1 | 9.7 49.5 285 9 5 37.3 20.4
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
04/28/2025 AT 1500 MDT | 04/28/2025 AT 1800 MDT
|
CAPE... +69.0 LI... -1.0 | CAPE... +95.3 LI... -0.6
CINH... -0.3 K INDEX... +17.7 | CINH... -14.5 K INDEX... +22.4
|
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 -55.1 -67.2 220 29 15 1.9 1.1 | -55.0 -67.0 220 27 14 1.5 0.9
45000 -52.3 -62.1 235 39 20 -0.1 -0.1 | -52.7 -62.9 230 36 18 0.4 0.2
40000 -53.5 -64.3 230 59 30 -0.8 -0.4 | -52.7 -62.9 230 51 26 -0.0 -0.0
38000 -52.3 -62.1 230 67 34 4.1 2.3 | -51.9 -61.4 230 58 30 2.9 1.6
36000 -49.9 -57.8 230 73 38 4.1 2.3 | -50.0 -58.0 230 68 35 2.9 1.6
34000 -47.3 -53.1 230 79 41 4.5 2.5 | -48.2 -54.8 230 74 38 3.5 1.9
32000 -44.7 -48.5 230 82 42 4.5 2.4 | -46.2 -51.2 230 72 37 3.4 1.9
30000 -41.9 -43.4 230 84 43 5.6 3.1 | -44.0 -47.2 235 69 36 4.9 2.7
29000 -40.3 -40.5 230 81 42 5.5 3.0 | -42.6 -44.7 235 64 33 4.8 2.6
28000 -38.6 -37.5 235 78 40 5.5 3.0 | -41.1 -42.0 240 59 31 4.8 2.6
27000 -37.0 -34.6 235 75 39 5.5 3.0 | -39.7 -39.5 240 54 28 4.9 2.7
26000 -35.2 -31.4 235 71 36 5.8 3.2 | -37.8 -36.0 245 51 26 6.6 3.6
25000 -33.5 -28.3 240 66 34 5.8 3.2 | -35.8 -32.4 250 49 25 6.6 3.6
24000 -31.7 -25.1 245 62 32 5.8 3.2 | -33.9 -29.0 255 47 24 6.4 3.5
23000 -30.0 -22.0 245 57 29 5.6 3.1 | -31.5 -24.7 255 43 22 8.1 4.5
22000 -27.9 -18.2 255 49 25 5.6 3.1 | -28.5 -19.3 255 37 19 8.1 4.5
21000 -26.2 -15.2 255 43 22 7.3 4.0 | -26.1 -15.0 255 32 16 9.0 4.9
20000 -23.9 -11.0 255 32 17 7.8 4.3 | -23.4 -10.1 255 24 12 9.0 4.9
19500 -22.7 -8.9 255 27 14 7.8 4.3 | -22.1 -7.8 250 20 10 9.0 5.0
19000 -21.6 -6.9 255 21 11 7.9 4.3 | -20.8 -5.4 250 16 8 9.1 5.0
18500 -20.4 -4.7 250 16 8 8.7 4.8 | -19.4 -2.9 245 13 6 9.0 4.9
18000 -19.1 -2.4 255 14 7 9.0 4.9 | -18.1 -0.6 250 10 5 8.9 4.9
17500 -17.8 -0.0 260 12 6 9.0 4.9 | -16.8 1.8 250 7 4 8.5 4.7
17000 -16.5 2.3 265 10 5 8.3 4.6 | -15.7 3.7 255 6 3 7.4 4.1
16500 -15.3 4.5 270 9 5 8.3 4.5 | -14.6 5.7 265 5 3 7.4 4.1
16000 -13.9 7.0 270 8 4 9.8 5.4 | -13.5 7.7 270 5 2 7.9 4.4
15500 -12.5 9.5 270 8 4 9.8 5.4 | -12.3 9.9 275 4 2 7.8 4.3
15000 -11.0 12.2 275 7 4 9.6 5.3 | -11.1 12.0 285 4 2 9.0 4.9
14500 -9.6 14.7 275 7 4 9.5 5.2 | -9.7 14.5 295 3 2 9.3 5.1
14000 -8.2 17.2 275 7 3 9.7 5.3 | -8.3 17.1 310 3 2 9.3 5.1
13500 -6.7 19.9 275 7 3 10.1 5.6 | -6.9 19.6 330 4 2 9.5 5.2
13000 -5.2 22.6 270 6 3 12.5 6.9 | -5.5 22.1 340 5 2 11.7 6.4
12500 -3.5 25.7 270 6 3 7.6 4.2 | -3.9 25.0 345 5 3 7.8 4.3
12000 -2.3 27.9 270 6 3 8.7 4.8 | -2.6 27.3 350 7 3 8.3 4.6
11750 -1.6 29.1 270 6 3 10.1 5.5 | -2.0 28.4 355 7 4 8.4 4.6
11500 -0.8 30.6 265 6 3 10.0 5.5 | -1.4 29.5 355 8 4 8.8 4.9
11250 -0.1 31.8 265 5 3 9.4 5.2 | -0.7 30.7 355 9 5 9.2 5.1
11000 0.6 33.1 265 5 3 9.6 5.2 | -0.0 32.0 355 10 5 9.1 5.0
10750 1.3 34.3 265 5 3 9.4 5.1 | 0.7 33.3 355 10 5 9.0 5.0
10500 2.0 35.6 265 5 3 9.4 5.2 | 1.3 34.3 355 11 6 9.0 5.0
10250 2.8 37.0 265 5 3 10.8 5.9 | 2.0 35.6 355 12 6 9.6 5.3
10000 3.6 38.5 265 5 2 11.0 6.1 | 2.8 37.0 355 12 6 9.9 5.4
9750 4.4 39.9 265 5 2 9.6 5.3 | 3.5 38.3 355 13 7 9.7 5.3
9500 5.1 41.2 265 5 2 9.0 4.9 | 4.2 39.6 355 14 7 9.2 5.1
9250 5.8 42.4 265 4 2 10.2 5.6 | 4.9 40.8 355 14 7 11.1 6.1
9000 6.6 43.9 265 4 2 11.0 6.0 | 5.8 42.4 355 15 8 10.9 6.0
8750 7.4 45.3 265 4 2 10.0 5.5 | 6.5 43.7 355 15 8 8.9 4.9
8500 8.1 46.6 265 4 2 10.3 5.6 | 7.2 45.0 355 15 8 9.0 5.0
8250 8.9 48.0 260 4 2 8.7 4.8 | 7.9 46.2 355 15 8 10.1 5.5
8000 9.6 49.3 260 4 2 13.8 7.6 | 8.7 47.7 355 15 8 11.9 6.5
7750 11.1 52.0 265 3 2 26.8 14.7 | 9.6 49.3 355 13 7 11.3 6.2
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.
Main Text Page