Soaring Guidance
Issued by NWS Pueblo, CO
Issued by NWS Pueblo, CO
647
UXUS97 KPUB 301350
SRGPUB
Soaring Forecast
National Weather Service Pueblo, Colorado
0650 MST Thursday, January 30, 2025
This forecast is for the Air Force Academy for Thursday, January 30, 2025:
If the trigger temperature of 37.1 F/2.8 C is reached...then
Thermal Soaring Index....................... Poor
Maximum rate of lift........................ 0 ft/min (0.0 m/s)
Maximum height of thermals.................. 10896 ft MSL (3292 ft AGL)
Forecast maximum temperature................... 35.0 F/2.1 C
Time of trigger temperature.................... None
Time of overdevelopment........................ None
Middle/high clouds during soaring window....... Broken/overcast opaque middle
Surface winds during soaring window............ 20 mph or less
Height of the -3 thermal index................. 8602 ft MSL (998 ft AGL)
Thermal soaring outlook for Friday 01/31....... Fair
Wave Soaring Index............................. Not available
Remarks...
Sunrise/Sunset.................... 07:06:53 / 17:18:25 MST
Total possible sunshine........... 10 hr 11 min 32 sec (611 min 32 sec)
Altitude of sun at 12:12:39 MST... 33.51 degrees
Upper air data from numerical model forecast valid on 01/30/2025 at 0500 MST
Freezing level.................. Entire airmass below 32 F / 0 C
Convective condensation level... 11108 ft MSL (3504 ft AGL)
Lifted condensation level....... 10995 ft MSL (3390 ft AGL)
Lifted index.................... +4.6
K index......................... +17.9
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 -54.5 -66.1 245 26 13 3.1 1.7 M M M M M
45000 -49.9 -57.8 240 23 12 3.1 1.7 M M M M M
40000 -45.4 -49.7 245 17 9 3.0 1.6 M M M M M
38000 -43.9 -47.0 250 12 6 0.6 0.3 M M M M M
36000 -43.6 -46.5 315 4 2 0.6 0.3 M M M M M
34000 -43.2 -45.8 035 11 5 0.7 0.4 M M M M M
32000 -43.2 -45.8 045 27 14 -0.1 -0.1 M M M M M
30000 -43.3 -45.9 050 45 23 -0.3 -0.2 M M M M M
29000 -42.9 -45.2 050 50 26 2.1 1.1 24.1 75.4 17.4 M M
28000 -42.3 -44.1 045 53 27 2.1 1.2 21.1 69.9 15.2 M M
27000 -41.6 -42.9 045 56 29 2.1 1.1 18.2 64.8 13.2 M M
26000 -40.7 -41.3 040 58 30 6.1 3.4 15.8 60.4 11.3 M M
25000 -39.0 -38.2 035 58 30 6.0 3.3 14.3 57.7 10.3 M M
24000 -37.2 -35.0 035 58 30 6.0 3.3 12.9 55.2 9.3 M M
23000 -35.3 -31.5 030 57 30 8.2 4.5 11.8 53.2 8.4 M M
22000 -32.1 -25.8 030 53 27 8.4 4.6 11.1 52.0 8.0 M M
21000 -29.6 -21.3 030 50 26 8.5 4.6 10.7 51.3 7.7 M M
20000 -27.1 -16.8 035 46 24 8.3 4.6 10.2 50.4 7.3 M M
19500 -25.9 -14.6 035 44 23 8.3 4.6 10.0 49.9 7.1 M M
19000 -24.6 -12.3 035 43 22 8.4 4.6 9.7 49.5 7.0 M M
18500 -23.4 -10.1 035 41 21 8.4 4.6 9.5 49.1 6.8 M M
18000 -22.2 -8.0 035 39 20 7.5 4.1 9.3 48.7 6.6 M M
17500 -21.1 -6.0 040 37 19 7.2 4.0 8.8 47.9 6.2 M M
17000 -20.1 -4.2 040 35 18 7.3 4.0 8.4 47.1 5.9 M M
16500 -18.9 -2.0 040 33 17 7.7 4.2 8.0 46.5 5.6 M M
16000 -17.8 -0.0 040 31 16 7.8 4.3 7.7 45.9 5.3 M M
15500 -16.7 1.9 040 30 15 7.6 4.2 7.4 45.3 5.0 M M
15000 -15.5 4.1 040 29 15 7.6 4.2 7.0 44.6 4.7 M M
14500 -14.4 6.1 040 29 15 8.2 4.5 6.7 44.1 4.4 M M
14000 -13.2 8.2 040 30 15 8.3 4.6 6.5 43.7 4.1 M M
13500 -12.0 10.4 040 31 16 7.8 4.3 6.2 43.2 3.9 M M
13000 -10.9 12.4 035 31 16 8.4 4.6 5.9 42.6 3.5 M M
12500 -10.2 13.6 030 31 16 1.8 1.0 5.0 41.0 2.8 M M
12000 -9.7 14.5 025 31 16 3.8 2.1 4.1 39.4 1.9 M M
11750 -9.4 15.1 025 31 16 3.9 2.2 3.6 38.5 1.4 M M
11500 -9.1 15.6 020 31 16 4.2 2.3 3.2 37.7 1.0 M M
11250 -8.7 16.3 020 31 16 4.8 2.6 2.8 37.0 0.6 M M
11000 -8.4 16.9 015 31 16 4.9 2.7 2.4 36.3 0.2 M M
10750 -8.0 17.6 015 31 16 4.8 2.7 2.0 35.6 -0.1 291 1.5
10500 -7.7 18.1 010 31 16 5.6 3.1 1.7 35.0 -0.5 272 1.4
10250 -7.2 19.0 010 31 16 7.3 4.0 1.4 34.5 -0.8 251 1.3
10000 -6.6 20.1 005 31 16 8.1 4.4 1.3 34.3 -0.9 226 1.1
9750 -6.0 21.2 005 30 16 7.7 4.2 1.1 34.0 -1.1 201 1.0
9500 -5.5 22.1 360 30 15 6.0 3.3 0.9 33.7 -1.3 179 0.9
9250 -5.2 22.6 360 30 15 4.7 2.6 0.6 33.0 -1.7 160 0.8
9000 -4.8 23.4 360 30 15 4.6 2.5 0.2 32.3 -2.0 142 0.7
8750 -4.5 23.9 355 30 15 3.3 1.8 -0.2 31.6 -2.5 126 0.6
8500 -4.3 24.3 355 28 15 1.8 1.0 -0.8 30.6 -3.0 113 0.6
8250 -4.2 24.4 350 26 14 1.4 0.8 -1.4 29.4 -3.7 102 0.5
8000 -4.1 24.6 345 24 12 1.5 0.8 -2.0 28.3 -4.3 91 0.5
7750 -4.0 24.8 340 20 10 1.4 0.7 -2.7 27.2 -4.9 81 0.4
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 * * * * * *
01/30/2025 at 0800 MST | 01/30/2025 at 1100 MST
|
CAPE... 0.0 LI... -0.2 | CAPE... +0.6 LI... -0.3
CINH... -0.1 K Index... +17.7 | CINH... 0.0 K Index... +10.8
|
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 -55.2 -67.4 250 24 12 2.2 1.2 | -54.7 -66.5 250 29 15 2.4 1.3
45000 -51.9 -61.4 245 19 10 2.4 1.3 | -51.0 -59.8 245 23 12 2.4 1.3
40000 -46.6 -51.9 270 13 6 3.6 2.0 | -47.1 -52.8 285 8 4 2.7 1.5
38000 -44.9 -48.8 295 10 5 1.1 0.6 | -45.7 -50.3 350 10 5 0.6 0.3
36000 -44.2 -47.6 010 10 5 1.0 0.6 | -45.4 -49.7 010 19 10 0.6 0.3
34000 -43.6 -46.5 035 19 10 0.9 0.5 | -45.0 -49.0 015 30 15 0.6 0.3
32000 -44.1 -47.4 035 39 20 -0.9 -0.5 | -44.8 -48.6 025 54 28 0.4 0.2
30000 -44.6 -48.3 035 59 31 -1.6 -0.9 | -44.6 -48.3 030 80 41 0.3 0.2
29000 -43.7 -46.7 035 65 34 4.5 2.5 | -42.9 -45.2 030 84 43 6.8 3.7
28000 -42.3 -44.1 035 70 36 4.4 2.4 | -40.9 -41.6 030 85 44 6.8 3.7
27000 -41.0 -41.8 030 74 38 4.4 2.4 | -38.9 -38.0 030 86 44 6.8 3.7
26000 -39.5 -39.1 030 77 40 6.6 3.6 | -37.0 -34.6 030 86 45 4.8 2.7
25000 -37.6 -35.7 030 76 39 6.4 3.5 | -35.5 -31.9 030 84 43 5.0 2.8
24000 -35.7 -32.3 030 75 39 6.4 3.5 | -34.0 -29.2 030 81 42 5.0 2.8
23000 -33.8 -28.8 025 73 38 6.2 3.4 | -32.1 -25.8 030 78 40 5.3 2.9
22000 -31.5 -24.7 025 65 33 6.2 3.4 | -30.5 -22.9 025 73 38 5.3 2.9
21000 -29.7 -21.5 025 58 30 6.0 3.3 | -28.9 -20.0 025 69 36 5.2 2.8
20000 -27.2 -17.0 025 52 27 9.4 5.1 | -27.0 -16.6 025 64 33 6.9 3.8
19500 -25.8 -14.4 025 50 26 9.4 5.2 | -26.0 -14.8 025 62 32 6.9 3.8
19000 -24.4 -11.9 025 48 25 9.4 5.2 | -24.9 -12.8 025 60 31 6.9 3.8
18500 -23.0 -9.4 025 46 24 9.5 5.2 | -23.9 -11.0 025 57 29 6.9 3.8
18000 -21.6 -6.9 025 45 23 9.1 5.0 | -22.8 -9.0 025 55 28 8.1 4.5
17500 -20.3 -4.5 025 45 23 9.0 4.9 | -21.6 -6.9 025 54 28 8.3 4.6
17000 -19.0 -2.2 025 45 23 8.6 4.7 | -20.4 -4.7 025 52 27 8.1 4.5
16500 -17.8 -0.0 025 44 23 7.6 4.2 | -19.2 -2.6 025 51 26 7.7 4.2
16000 -16.7 1.9 025 44 23 7.7 4.2 | -18.1 -0.6 025 50 26 7.7 4.2
15500 -15.6 3.9 030 43 22 6.8 3.7 | -17.0 1.4 025 49 25 7.8 4.3
15000 -14.6 5.7 030 43 22 6.9 3.8 | -15.8 3.6 020 49 25 7.8 4.3
14500 -13.6 7.5 030 42 22 6.9 3.8 | -14.7 5.5 020 49 25 7.1 3.9
14000 -12.6 9.3 035 42 22 6.9 3.8 | -13.7 7.3 020 49 25 7.0 3.8
13500 -11.6 11.1 035 43 22 7.4 4.1 | -12.6 9.3 020 49 25 8.0 4.4
13000 -10.5 13.1 035 44 22 8.2 4.5 | -11.4 11.5 015 49 25 9.2 5.1
12500 -9.6 14.7 030 45 23 3.8 2.1 | -10.7 12.7 015 48 25 4.4 2.4
12000 -8.9 16.0 030 45 23 5.2 2.8 | -9.5 14.9 010 49 25 7.8 4.3
11750 -8.5 16.7 025 46 23 5.2 2.8 | -8.9 16.0 010 49 25 8.2 4.5
11500 -8.1 17.4 025 46 24 6.1 3.3 | -8.3 17.1 010 49 25 7.4 4.0
11250 -7.7 18.1 025 46 24 4.5 2.4 | -7.8 18.0 010 49 25 6.7 3.7
11000 -7.5 18.5 020 46 24 2.4 1.3 | -7.3 18.9 005 49 25 6.9 3.8
10750 -7.3 18.9 020 46 24 3.2 1.7 | -6.8 19.8 005 48 25 6.6 3.6
10500 -7.1 19.2 020 46 23 0.9 0.5 | -6.4 20.5 005 48 25 5.3 2.9
10250 -7.1 19.2 015 45 23 -1.0 -0.6 | -6.1 21.0 005 47 24 1.6 0.9
10000 -7.2 19.0 015 44 23 -0.7 -0.4 | -6.1 21.0 360 47 24 -0.8 -0.4
9750 -7.2 19.0 015 43 22 -0.7 -0.4 | -6.1 21.0 360 46 24 -1.4 -0.7
9500 -7.2 19.0 010 42 22 -0.2 -0.1 | -6.3 20.7 360 45 23 -3.6 -2.0
9250 -7.2 19.0 010 41 21 0.6 0.3 | -6.6 20.1 355 43 22 -3.9 -2.1
9000 -7.1 19.2 005 40 21 1.6 0.9 | -6.9 19.6 355 42 21 -4.0 -2.2
8750 -6.9 19.6 360 38 19 3.5 1.9 | -7.0 19.4 355 40 20 0.7 0.4
8500 -6.6 20.1 360 35 18 5.1 2.8 | -6.7 19.9 350 37 19 6.1 3.4
8250 -6.2 20.8 355 32 17 5.2 2.9 | -6.3 20.7 345 35 18 5.4 2.9
8000 -5.9 21.4 350 30 15 6.0 3.3 | -5.8 21.6 345 33 17 8.6 4.7
7750 -5.3 22.5 345 25 13 8.6 4.7 | -4.9 23.2 340 27 14 16.9 9.3
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
01/30/2025 at 1400 MST | 01/30/2025 at 1700 MST
|
CAPE... 0.0 LI... -0.5 | CAPE... 0.0 LI... +2.7
CINH... 0.0 K Index... +10.9 | CINH... 0.0 K Index... +1.4
|
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 -67.2 265 27 14 2.8 1.6 | -54.4 -65.9 265 27 14 3.0 1.6
45000 -50.9 -59.6 270 23 12 2.8 1.5 | -50.0 -58.0 280 22 11 2.7 1.5
40000 -47.4 -53.3 280 12 6 2.3 1.3 | -48.4 -55.1 305 22 11 0.9 0.5
38000 -46.8 -52.2 330 11 6 -1.7 -0.9 | -48.4 -55.1 320 25 13 -1.3 -0.7
36000 -47.8 -54.0 005 26 13 -1.7 -0.9 | -49.1 -56.4 340 33 17 -1.3 -0.7
34000 -48.8 -55.8 015 43 22 -0.0 -0.0 | -49.9 -57.8 350 44 23 2.1 1.1
32000 -46.3 -51.3 015 58 30 4.4 2.4 | -46.6 -51.9 360 51 26 5.6 3.1
30000 -43.7 -46.7 015 72 37 5.2 2.8 | -43.2 -45.8 005 59 31 5.8 3.2
29000 -41.6 -42.9 015 74 38 7.1 3.9 | -41.4 -42.5 010 62 32 6.1 3.4
28000 -39.5 -39.1 020 75 38 7.0 3.9 | -39.5 -39.1 010 64 33 6.1 3.4
27000 -37.4 -35.3 020 75 39 7.0 3.9 | -37.7 -35.9 010 66 34 6.1 3.3
26000 -35.4 -31.7 020 76 39 5.5 3.0 | -35.9 -32.6 015 67 35 5.6 3.1
25000 -33.8 -28.8 020 76 39 5.6 3.1 | -34.3 -29.7 015 67 35 5.6 3.1
24000 -32.1 -25.8 020 76 39 5.6 3.1 | -32.6 -26.7 015 67 35 5.6 3.1
23000 -30.4 -22.7 020 75 39 5.3 2.9 | -30.4 -22.7 020 66 34 5.9 3.3
22000 -28.8 -19.8 020 74 38 5.4 2.9 | -28.7 -19.7 020 65 34 6.0 3.3
21000 -26.8 -16.2 020 72 37 5.5 3.0 | -26.9 -16.4 025 65 33 6.0 3.3
20000 -25.4 -13.7 015 69 36 4.7 2.6 | -24.8 -12.6 025 63 33 7.1 3.9
19500 -24.7 -12.5 015 67 35 4.7 2.6 | -23.8 -10.8 025 63 32 7.1 3.9
19000 -24.0 -11.2 015 66 34 4.7 2.6 | -22.7 -8.9 025 62 32 7.1 3.9
18500 -23.3 -9.9 015 64 33 4.6 2.5 | -21.6 -6.9 025 61 32 7.3 4.0
18000 -22.5 -8.5 015 62 32 6.4 3.5 | -20.7 -5.3 025 60 31 5.3 2.9
17500 -21.6 -6.9 015 60 31 6.5 3.6 | -19.9 -3.8 025 59 30 5.5 3.0
17000 -20.6 -5.1 020 58 30 7.1 3.9 | -19.1 -2.4 025 57 29 5.2 2.8
16500 -19.5 -3.1 020 55 28 7.6 4.2 | -18.3 -0.9 025 54 28 5.0 2.7
16000 -18.3 -0.9 020 52 27 7.7 4.2 | -17.6 0.3 025 52 27 5.5 3.0
15500 -17.2 1.0 020 51 26 7.8 4.3 | -16.6 2.1 025 49 25 7.1 3.9
15000 -16.1 3.0 020 49 25 7.7 4.2 | -15.5 4.1 025 46 24 7.0 3.8
14500 -14.9 5.2 020 49 25 8.8 4.8 | -14.5 5.9 025 45 23 7.4 4.0
14000 -13.6 7.5 020 49 25 8.8 4.8 | -13.4 7.9 020 43 22 7.5 4.1
13500 -12.3 9.9 015 49 25 8.3 4.5 | -12.4 9.7 020 43 22 5.9 3.2
13000 -11.1 12.0 015 48 25 7.8 4.3 | -11.6 11.1 015 44 22 5.7 3.2
12500 -9.8 14.4 015 48 25 6.9 3.8 | -10.6 12.9 015 44 23 7.6 4.2
12000 -9.3 15.3 015 48 25 3.8 2.1 | -9.7 14.5 010 43 22 6.0 3.3
11750 -9.0 15.8 010 48 25 3.3 1.8 | -9.3 15.3 010 42 22 7.1 3.9
11500 -8.8 16.2 010 48 25 2.8 1.5 | -8.7 16.3 010 42 22 7.9 4.3
11250 -8.6 16.5 010 48 24 2.3 1.3 | -8.2 17.2 005 42 22 5.1 2.8
11000 -8.4 16.9 005 47 24 2.3 1.2 | -7.9 17.8 005 42 22 4.1 2.2
10750 -8.2 17.2 005 47 24 2.4 1.3 | -7.5 18.5 005 42 22 3.3 1.8
10500 -8.0 17.6 360 47 24 2.4 1.3 | -7.4 18.7 360 42 22 1.1 0.6
10250 -7.8 18.0 360 46 24 3.0 1.6 | -7.2 19.0 360 42 21 2.8 1.6
10000 -7.6 18.3 355 45 23 3.7 2.0 | -6.9 19.6 355 41 21 4.5 2.5
9750 -7.3 18.9 355 44 23 3.4 1.9 | -6.5 20.3 355 41 21 5.8 3.2
9500 -7.1 19.2 355 44 23 2.5 1.4 | -6.0 21.2 355 42 22 7.1 3.9
9250 -6.8 19.8 355 44 22 3.8 2.1 | -5.5 22.1 350 42 22 7.2 3.9
9000 -6.3 20.7 350 43 22 10.0 5.5 | -4.9 23.2 350 42 22 8.7 4.8
8750 -5.5 22.1 350 41 21 10.6 5.8 | -4.3 24.3 350 41 21 7.7 4.2
8500 -4.9 23.2 350 39 20 7.9 4.3 | -3.8 25.2 350 39 20 6.3 3.4
8250 -4.2 24.4 350 36 19 8.4 4.6 | -3.3 26.1 345 37 19 7.0 3.9
8000 -3.6 25.5 345 33 17 10.3 5.6 | -2.8 27.0 345 35 18 6.0 3.3
7750 -2.7 27.1 345 27 14 15.4 8.4 | -2.5 27.5 345 26 14 3.0 1.6
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.
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