745
UXUS97 KPUB 201303
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO, COLORADO
0603 MST WEDNESDAY, NOVEMBER 20, 2024
THIS FORECAST IS FOR THE AIR FORCE ACADEMY FOR WEDNESDAY, NOVEMBER 20, 2024:
IF THE TRIGGER TEMPERATURE OF 42.7 F/5.9 C IS REACHED...THEN
THERMAL SOARING INDEX....................... FAIR
MAXIMUM RATE OF LIFT........................ 372 FT/MIN (1.9 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 12131 FT MSL (4497 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 45.0 F/7.7 C
TIME OF TRIGGER TEMPERATURE.................... 1200 MST
TIME OF OVERDEVELOPMENT........................ NONE
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... NONE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 10907 FT MSL (3273 FT AGL)
THERMAL SOARING OUTLOOK FOR THURSDAY 11/21..... GOOD
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 06:48:33 / 16:41:35 MST
TOTAL POSSIBLE SUNSHINE........... 9 HR 53 MIN 3 SEC (593 MIN 3 SEC)
ALTITUDE OF SUN AT 11:45:04 MST... 30.99 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 11/20/2024 AT 0500 MST
FREEZING LEVEL.................. ENTIRE AIRMASS BELOW 32 F / 0 C
CONVECTIVE CONDENSATION LEVEL... 24250 FT MSL (16616 FT AGL)
LIFTED CONDENSATION LEVEL....... 19195 FT MSL (11561 FT AGL)
LIFTED INDEX.................... +11.0
K INDEX......................... -13.9
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 -58.9 -74.0 285 50 26 -3.0 -1.6 M M M M M
45000 -63.3 -81.9 290 89 46 -3.4 -1.9 M M M M M
40000 -63.2 -81.8 300 99 51 0.3 0.1 M M M M M
38000 -61.3 -78.3 300 100 51 6.5 3.5 M M M M M
36000 -56.9 -70.4 295 96 50 6.4 3.5 M M M M M
34000 -52.9 -63.2 295 93 48 7.8 4.3 M M M M M
32000 -48.1 -54.6 295 89 46 7.9 4.3 M M M M M
30000 -43.3 -45.9 300 86 44 8.2 4.5 25.5 77.9 14.0 M M
29000 -40.9 -41.6 300 85 44 8.3 4.5 24.8 76.7 13.7 M M
28000 -38.4 -37.1 300 84 43 8.3 4.5 24.3 75.7 13.5 M M
27000 -35.9 -32.6 300 83 43 7.9 4.4 23.9 74.9 13.3 M M
26000 -33.6 -28.5 300 79 41 7.7 4.2 23.0 73.3 12.7 M M
25000 -31.3 -24.3 300 75 38 7.7 4.2 22.2 72.0 12.2 M M
24000 -29.0 -20.2 300 70 36 7.7 4.2 21.6 70.8 11.9 M M
23000 -26.1 -15.0 300 65 33 7.8 4.3 20.6 69.1 11.2 M M
22000 -23.8 -10.8 305 60 31 7.8 4.3 19.9 67.9 10.8 M M
21000 -21.4 -6.5 305 56 29 8.4 4.6 19.4 66.9 10.4 M M
20000 -18.9 -2.0 305 53 27 8.3 4.6 18.8 65.9 10.1 M M
19500 -17.6 0.3 305 51 26 8.4 4.6 18.6 65.5 9.9 M M
19000 -16.4 2.5 305 49 25 8.4 4.6 18.4 65.1 9.8 M M
18500 -15.2 4.6 305 48 25 7.8 4.3 18.1 64.7 9.6 M M
18000 -14.0 6.8 305 47 24 7.7 4.2 17.8 64.0 9.3 M M
17500 -12.9 8.8 305 45 23 7.0 3.9 17.5 63.4 9.1 M M
17000 -12.0 10.4 305 44 23 5.6 3.1 16.8 62.3 8.5 M M
16500 -11.2 11.8 305 42 22 5.7 3.1 16.1 61.0 8.0 M M
16000 -10.4 13.3 305 41 21 5.2 2.9 15.4 59.8 7.4 M M
15500 -9.6 14.7 305 41 21 5.3 2.9 14.7 58.4 6.7 M M
15000 -8.9 16.0 305 41 21 4.2 2.3 13.9 57.1 6.0 M M
14500 -8.3 17.1 305 41 21 3.8 2.1 13.0 55.3 5.2 M M
14000 -7.7 18.1 305 41 21 2.7 1.5 12.0 53.6 4.3 M M
13500 -7.5 18.5 305 40 21 1.8 1.0 10.7 51.3 3.1 M M
13000 -7.2 19.0 305 39 20 2.5 1.4 9.4 49.0 1.9 M M
12500 -6.7 19.9 305 38 19 2.8 1.5 8.5 47.2 1.0 M M
12000 -6.4 20.5 305 37 19 1.8 1.0 7.2 45.0 -0.2 368 1.9
11750 -6.3 20.7 305 37 19 1.6 0.9 6.6 43.8 -0.8 357 1.8
11500 -6.1 21.0 305 36 18 1.6 0.9 5.9 42.7 -1.4 346 1.8
11250 -6.0 21.2 305 35 18 1.5 0.8 5.3 41.5 -2.0 335 1.7
11000 -5.9 21.4 305 34 17 1.9 1.0 4.7 40.4 -2.6 324 1.6
10750 -5.7 21.7 305 32 17 2.3 1.2 4.1 39.3 -3.2 311 1.6
10500 -5.5 22.1 305 31 16 3.1 1.7 3.5 38.3 -3.7 298 1.5
10250 -5.3 22.5 305 29 15 -0.1 -0.1 2.9 37.3 -4.3 285 1.5
10000 -5.5 22.1 305 28 14 0.3 0.2 2.1 35.7 -5.1 281 1.4
9750 -5.2 22.6 305 25 13 3.7 2.0 1.6 34.8 -5.7 267 1.4
9500 -5.0 23.0 305 23 12 4.0 2.2 1.1 33.9 -6.2 252 1.3
9250 -4.7 23.5 305 21 11 0.0 0.0 0.6 33.0 -6.7 238 1.2
9000 -5.0 23.0 310 17 9 -2.8 -1.5 -0.4 31.3 -7.6 237 1.2
8750 -5.1 22.8 305 17 9 -0.7 -0.4 -1.2 29.8 -8.5 232 1.2
8500 -5.2 22.6 300 16 8 -1.0 -0.5 -2.0 28.3 -9.3 228 1.2
8250 -5.2 22.6 290 16 8 -2.1 -1.1 -2.9 26.8 -10.2 223 1.1
8000 -7.3 18.9 280 11 5 -26.4 -14.5 -6.3 20.6 -13.7 270 1.4
7750 -8.8 16.2 260 6 3 -3.6 -2.0 -8.6 16.5 -16.1 309 1.6
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 * * * * * *
11/20/2024 AT 0800 MST | 11/20/2024 AT 1100 MST
|
CAPE... 0.0 LI... +5.6 | CAPE... 0.0 LI... +5.8
CINH... 0.0 K INDEX... -12.2 | CINH... 0.0 K INDEX... -7.4
|
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 -60.1 -76.2 290 48 25 -3.8 -2.1 | -61.8 -79.2 280 48 25 -3.1 -1.7
45000 -65.8 -86.4 290 89 46 -3.1 -1.7 | -66.4 -87.5 290 84 43 2.4 1.3
40000 -62.8 -81.0 300 97 50 2.0 1.1 | -62.4 -80.3 295 87 45 2.7 1.5
38000 -59.6 -75.3 300 96 49 7.0 3.8 | -58.8 -73.8 300 87 45 7.5 4.1
36000 -55.4 -67.7 300 93 48 7.0 3.8 | -54.3 -65.7 295 86 45 7.5 4.1
34000 -51.2 -60.2 295 89 46 7.1 3.9 | -49.8 -57.6 295 84 43 7.4 4.1
32000 -46.9 -52.4 295 81 42 7.1 3.9 | -45.4 -49.7 290 79 41 7.4 4.1
30000 -42.5 -44.5 290 74 38 8.0 4.4 | -40.9 -41.6 290 73 37 7.6 4.2
29000 -40.1 -40.2 290 71 37 8.0 4.4 | -38.6 -37.5 290 69 35 7.6 4.2
28000 -37.7 -35.9 295 68 35 8.0 4.4 | -36.3 -33.3 290 65 34 7.6 4.2
27000 -35.3 -31.5 295 66 34 8.2 4.5 | -34.0 -29.2 290 61 32 7.9 4.3
26000 -32.8 -27.0 295 64 33 8.2 4.5 | -31.0 -23.8 290 58 30 8.0 4.4
25000 -30.4 -22.7 295 62 32 8.2 4.5 | -28.6 -19.5 290 55 28 8.0 4.4
24000 -27.3 -17.1 295 59 30 7.9 4.3 | -26.3 -15.3 290 51 26 6.6 3.6
23000 -25.0 -13.0 295 55 28 7.9 4.3 | -24.4 -11.9 290 48 25 6.7 3.7
22000 -22.6 -8.7 300 51 26 7.9 4.3 | -22.4 -8.3 290 44 23 6.7 3.7
21000 -20.3 -4.5 300 47 24 7.3 4.0 | -20.3 -4.5 285 41 21 7.6 4.2
20000 -18.1 -0.6 300 42 22 7.4 4.0 | -18.0 -0.4 285 38 19 7.5 4.1
19500 -17.0 1.4 295 39 20 7.4 4.0 | -16.9 1.6 285 36 19 7.5 4.1
19000 -15.9 3.4 295 37 19 7.3 4.0 | -15.7 3.7 280 35 18 7.5 4.1
18500 -14.7 5.5 295 35 18 7.7 4.2 | -14.6 5.7 280 34 18 7.7 4.2
18000 -13.6 7.5 300 33 17 7.6 4.2 | -13.4 7.9 285 34 17 7.7 4.2
17500 -12.4 9.7 300 31 16 7.0 3.9 | -12.3 9.9 285 34 17 7.1 3.9
17000 -11.5 11.3 300 30 16 6.4 3.5 | -11.3 11.7 285 32 17 6.6 3.6
16500 -10.5 13.1 305 30 15 6.4 3.5 | -10.3 13.5 290 31 16 6.4 3.5
16000 -9.6 14.7 305 30 15 6.4 3.5 | -9.5 14.9 290 29 15 4.6 2.5
15500 -8.6 16.5 305 30 15 6.7 3.7 | -8.8 16.2 295 27 14 4.8 2.6
15000 -7.8 18.0 310 29 15 3.6 2.0 | -8.2 17.2 300 26 13 4.2 2.3
14500 -7.3 18.9 310 28 15 3.4 1.9 | -7.6 18.3 300 25 13 4.2 2.3
14000 -6.8 19.8 310 28 14 3.3 1.8 | -6.9 19.6 305 24 12 4.2 2.3
13500 -6.4 20.5 310 27 14 3.2 1.7 | -6.3 20.7 310 23 12 4.2 2.3
13000 -5.9 21.4 315 26 13 2.8 1.5 | -5.7 21.7 310 23 12 4.6 2.5
12500 -5.5 22.1 315 25 13 2.4 1.3 | -5.0 23.0 315 23 12 3.7 2.0
12000 -5.2 22.6 315 25 13 2.3 1.2 | -4.5 23.9 315 23 12 2.9 1.6
11750 -5.0 23.0 315 25 13 2.3 1.3 | -4.3 24.3 315 23 12 2.7 1.5
11500 -4.9 23.2 315 25 13 2.1 1.2 | -4.1 24.6 315 23 12 2.5 1.4
11250 -4.7 23.5 315 25 13 0.3 0.2 | -4.0 24.8 315 23 12 1.1 0.6
11000 -4.8 23.4 315 24 12 0.5 0.3 | -3.9 25.0 315 22 11 1.1 0.6
10750 -4.6 23.7 315 23 12 1.7 0.9 | -3.8 25.2 315 20 10 1.6 0.9
10500 -4.5 23.9 315 22 11 1.7 0.9 | -3.7 25.3 320 19 10 1.9 1.0
10250 -4.4 24.1 315 21 11 0.6 0.3 | -3.6 25.5 320 17 9 0.3 0.2
10000 -4.4 24.1 315 20 10 0.4 0.2 | -3.6 25.5 315 16 8 1.6 0.9
9750 -4.3 24.3 315 18 9 1.8 1.0 | -3.3 26.1 315 14 7 4.1 2.2
9500 -4.2 24.4 315 17 9 0.7 0.4 | -3.0 26.6 315 12 6 3.8 2.1
9250 -4.1 24.6 315 15 8 3.7 2.0 | -2.8 27.0 315 10 5 2.4 1.3
9000 -3.7 25.3 315 13 7 3.3 1.8 | -2.6 27.3 315 9 5 3.6 2.0
8750 -3.7 25.3 315 11 6 -0.3 -0.1 | -2.2 28.0 315 8 4 6.3 3.5
8500 -3.6 25.5 310 9 5 1.8 1.0 | -1.8 28.8 310 7 3 5.1 2.8
8250 -3.6 25.5 310 7 4 -2.8 -1.5 | -1.4 29.5 310 5 3 7.4 4.1
8000 -4.2 24.4 300 9 5 -12.4 -6.8 | -0.6 30.9 305 5 2 12.5 6.9
7750 -5.3 22.5 290 7 4 -15.2 -8.3 | 1.4 34.5 300 3 2 12.8 7.0
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
11/20/2024 AT 1400 MST | 11/20/2024 AT 1700 MST
|
CAPE... 0.0 LI... +5.4 | CAPE... 0.0 LI... +4.7
CINH... 0.0 K INDEX... -0.0 | CINH... 0.0 K INDEX... +1.3
|
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 -63.7 -82.7 280 57 29 -2.5 -1.3 | -64.5 -84.1 285 56 29 -1.7 -1.0
45000 -67.3 -89.1 285 84 43 3.1 1.7 | -66.9 -88.4 285 87 45 3.1 1.7
40000 -62.4 -80.3 295 89 46 3.3 1.8 | -62.2 -80.0 295 96 49 3.1 1.7
38000 -58.8 -73.8 295 88 45 7.4 4.1 | -58.6 -73.5 295 93 48 7.5 4.1
36000 -54.3 -65.7 295 85 44 7.4 4.1 | -53.5 -64.3 295 87 45 7.5 4.1
34000 -49.3 -56.7 295 80 41 7.6 4.2 | -48.9 -56.0 300 81 42 7.9 4.3
32000 -44.7 -48.5 295 74 38 7.6 4.2 | -44.2 -47.6 300 75 38 7.9 4.3
30000 -40.1 -40.2 295 69 35 7.8 4.3 | -39.6 -39.3 295 67 34 7.2 4.0
29000 -37.8 -36.0 295 66 34 7.8 4.3 | -37.5 -35.5 295 61 32 7.2 4.0
28000 -35.4 -31.7 295 63 33 7.8 4.3 | -35.3 -31.5 295 56 29 7.2 4.0
27000 -33.1 -27.6 295 60 31 8.3 4.5 | -33.0 -27.4 290 51 27 8.7 4.7
26000 -30.6 -23.1 295 56 29 8.2 4.5 | -30.5 -22.9 290 48 25 8.5 4.7
25000 -28.1 -18.6 295 52 27 8.3 4.5 | -27.9 -18.2 290 44 23 8.5 4.7
24000 -25.7 -14.3 295 48 25 7.3 4.0 | -25.4 -13.7 285 41 21 7.9 4.3
23000 -23.6 -10.5 290 46 24 7.1 3.9 | -23.1 -9.6 290 42 22 7.7 4.2
22000 -21.5 -6.7 290 44 23 7.1 3.9 | -20.2 -4.4 300 43 22 7.7 4.2
21000 -19.5 -3.1 285 42 22 6.8 3.7 | -18.1 -0.6 300 42 22 6.4 3.5
20000 -16.9 1.6 285 39 20 6.9 3.8 | -16.2 2.8 305 39 20 6.4 3.5
19500 -15.9 3.4 285 38 19 6.9 3.8 | -15.3 4.5 305 37 19 6.4 3.5
19000 -14.9 5.2 280 36 19 6.8 3.7 | -14.3 6.3 305 36 18 6.2 3.4
18500 -13.9 7.0 280 35 18 6.2 3.4 | -13.5 7.7 305 34 17 5.4 3.0
18000 -13.0 8.6 285 33 17 6.3 3.5 | -12.7 9.1 310 32 17 5.4 3.0
17500 -12.1 10.2 285 31 16 5.6 3.1 | -11.9 10.6 310 30 16 5.3 2.9
17000 -11.3 11.7 290 28 15 5.4 3.0 | -11.1 12.0 310 28 15 5.3 2.9
16500 -10.5 13.1 290 26 13 5.3 2.9 | -10.3 13.5 315 26 14 5.9 3.2
16000 -9.8 14.4 295 24 12 4.9 2.7 | -9.3 15.3 320 26 14 7.2 3.9
15500 -9.1 15.6 305 22 11 4.8 2.6 | -8.3 17.1 320 27 14 7.2 3.9
15000 -8.3 17.1 310 21 11 6.1 3.3 | -7.2 19.0 325 29 15 7.2 4.0
14500 -7.4 18.7 315 22 11 6.0 3.3 | -6.1 21.0 325 32 16 7.4 4.1
14000 -6.5 20.3 320 23 12 6.0 3.3 | -5.2 22.6 325 35 18 4.6 2.5
13500 -5.6 21.9 320 26 13 6.1 3.4 | -4.6 23.7 325 36 19 4.4 2.4
13000 -4.8 23.4 320 29 15 4.4 2.4 | -4.0 24.8 320 37 19 3.3 1.8
12500 -4.3 24.3 315 33 17 1.5 0.8 | -3.6 25.5 320 33 17 2.3 1.2
12000 -4.1 24.6 310 34 18 1.4 0.8 | -3.3 26.1 320 31 16 2.9 1.6
11750 -4.0 24.8 305 33 17 1.6 0.9 | -3.0 26.6 315 30 15 3.5 1.9
11500 -3.9 25.0 305 31 16 1.5 0.8 | -2.8 27.0 310 28 15 2.7 1.5
11250 -3.8 25.2 300 29 15 1.6 0.9 | -2.6 27.3 305 27 14 2.0 1.1
11000 -3.6 25.5 295 27 14 4.0 2.2 | -2.4 27.7 300 26 13 4.4 2.4
10750 -3.2 26.2 295 25 13 6.0 3.3 | -1.9 28.6 300 25 13 6.4 3.5
10500 -2.8 27.0 290 22 12 4.2 2.3 | -1.5 29.3 290 23 12 5.3 2.9
10250 -2.4 27.7 285 20 11 9.4 5.1 | -1.0 30.2 285 22 11 7.9 4.3
10000 -1.6 29.1 280 18 9 10.2 5.6 | -0.3 31.5 280 21 11 9.5 5.2
9750 -1.1 30.0 275 16 8 5.5 3.0 | 0.3 32.5 280 20 10 8.1 4.4
9500 -0.6 30.9 270 14 7 7.4 4.1 | 0.9 33.6 280 19 10 9.2 5.0
9250 -0.1 31.8 260 13 6 4.5 2.5 | 1.6 34.9 275 18 9 6.3 3.5
9000 0.2 32.4 255 11 6 5.5 3.0 | 1.9 35.4 270 17 9 5.7 3.2
8750 0.8 33.4 245 9 5 8.8 4.8 | 2.5 36.5 270 16 8 7.3 4.0
8500 1.4 34.5 230 8 4 8.0 4.4 | 3.0 37.4 265 15 8 8.8 4.8
8250 2.0 35.6 210 7 4 8.0 4.4 | 3.5 38.3 265 14 7 1.3 0.7
8000 2.6 36.7 205 7 3 9.6 5.2 | 3.0 37.4 255 13 7 -14.0 -7.7
7750 3.4 38.1 190 5 3 12.7 7.0 | 1.7 35.1 245 9 5 -16.4 -9.0
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