950
UXUS97 KGJT 241305
SRGGJT
SOARING FORECAST
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO
705 AM MDT THURSDAY, JULY 24, 2025
THIS FORECAST IS FOR THURSDAY, JULY 24, 2025:
IF THE TRIGGER TEMPERATURE OF 81.2 F/27.3 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1451 FT/MIN (7.4 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 20984 FT MSL (15376 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 94.0 F/34.9 C
TIME OF TRIGGER TEMPERATURE.................... 0945 MDT
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................. 17904 FT MSL (12295 FT AGL)
THERMAL SOARING OUTLOOK FOR FRIDAY 07/25....... EXCELLENT
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 06:08:15 / 20:33:07 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 24 MIN 52 SEC (864 MIN 52 SEC)
ALTITUDE OF SUN AT 13:20:41 MDT... 70.06 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 07/24/2025 AT 0600 MDT
FREEZING LEVEL.................. 15382 FT MSL (9774 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 20777 FT MSL (15169 FT AGL)
LIFTED CONDENSATION LEVEL....... 21104 FT MSL (15496 FT AGL)
LIFTED INDEX.................... -0.9
K INDEX......................... +11.4
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 -58.9 -74.0 220 25 13 2.8 1.6 M M M M M
45000 -55.1 -67.2 215 37 19 1.4 0.8 M M M M M
40000 -52.6 -62.7 200 41 21 5.1 2.8 M M M M M
38000 -49.6 -57.3 205 35 18 5.0 2.7 M M M M M
36000 -46.6 -51.9 215 31 16 5.0 2.7 M M M M M
34000 -42.4 -44.3 220 29 15 7.5 4.1 M M M M M
32000 -37.3 -35.1 230 28 15 7.5 4.1 M M M M M
30000 -32.8 -27.0 235 24 12 7.4 4.1 41.5 106.8 5.4 M M
29000 -30.6 -23.1 235 21 11 7.4 4.1 40.7 105.2 4.8 M M
28000 -28.4 -19.1 235 18 9 7.6 4.1 39.9 103.9 4.3 M M
27000 -26.1 -15.0 240 17 9 7.6 4.2 39.0 102.2 3.6 M M
26000 -23.8 -10.8 240 16 8 7.6 4.2 38.2 100.8 3.0 M M
25000 -21.6 -6.9 245 15 8 7.7 4.2 37.5 99.5 2.5 M M
24000 -19.2 -2.6 250 14 7 7.9 4.3 36.8 98.2 1.9 M M
23000 -16.8 1.8 260 12 6 7.9 4.3 36.1 96.9 1.3 M M
22000 -14.5 5.9 265 11 6 7.8 4.3 35.5 95.9 0.8 M M
21000 -12.3 9.9 260 11 5 7.3 4.0 34.6 94.3 0.1 M M
20000 -10.1 13.8 255 10 5 7.3 4.0 33.8 92.8 -0.6 1366 6.9
19500 -9.0 15.8 250 10 5 7.5 4.1 33.4 92.1 -1.0 1319 6.7
19000 -7.5 18.5 235 11 6 5.8 3.2 32.5 90.6 -1.7 1254 6.4
18500 -6.7 19.9 225 12 6 5.8 3.2 31.9 89.3 -2.4 1214 6.2
18000 -5.9 21.4 215 13 7 6.2 3.4 31.2 88.2 -3.0 1174 6.0
17500 -5.0 23.0 210 13 7 6.5 3.6 30.6 87.1 -3.6 1134 5.8
17000 -4.1 24.6 205 13 7 7.5 4.1 30.1 86.1 -4.3 1093 5.6
16500 -2.9 26.8 205 12 6 9.0 4.9 29.9 85.8 -4.5 1040 5.3
16000 -1.5 29.3 205 12 6 9.0 4.9 29.8 85.6 -4.6 985 5.0
15500 -0.2 31.6 205 11 6 9.3 5.1 29.7 85.4 -4.7 929 4.7
15000 1.2 34.2 210 11 6 9.2 5.1 29.6 85.3 -4.8 873 4.4
14500 2.6 36.7 210 11 5 9.3 5.1 29.5 85.1 -4.9 817 4.1
14000 4.0 39.2 210 10 5 9.3 5.1 29.4 85.0 -5.0 760 3.9
13500 5.4 41.7 210 10 5 9.0 5.0 29.4 84.9 -5.1 704 3.6
13000 6.7 44.1 215 10 5 8.9 4.9 29.2 84.6 -5.3 650 3.3
12500 8.0 46.4 215 9 5 8.8 4.8 29.1 84.4 -5.4 595 3.0
12000 9.3 48.7 220 9 5 8.6 4.7 28.9 84.0 -5.6 542 2.8
11500 10.6 51.1 220 9 4 8.3 4.6 28.7 83.7 -5.8 488 2.5
11000 11.8 53.2 225 8 4 7.5 4.1 28.4 83.1 -6.2 439 2.2
10500 13.0 55.4 225 8 4 10.2 5.6 28.2 82.7 -6.4 388 2.0
10250 13.8 56.8 225 8 4 9.5 5.2 28.2 82.8 -6.4 357 1.8
10000 14.3 57.7 225 7 4 7.4 4.1 28.1 82.6 -6.6 332 1.7
9750 14.9 58.8 225 7 4 8.6 4.7 27.9 82.3 -6.7 307 1.6
9500 15.5 59.9 220 7 3 6.1 3.4 27.8 82.1 -6.9 281 1.4
9250 15.9 60.6 215 6 3 6.1 3.4 27.5 81.4 -7.2 263 1.3
9000 16.5 61.7 210 6 3 8.2 4.5 27.3 81.1 -7.4 238 1.2
8750 17.1 62.8 200 5 3 8.0 4.4 27.2 80.9 -7.6 214 1.1
8500 17.6 63.7 195 5 3 6.7 3.7 27.0 80.6 -7.8 189 1.0
8250 18.0 64.4 185 6 3 5.4 3.0 26.7 80.1 -8.1 170 0.9
8000 18.5 65.3 175 6 3 5.9 3.2 26.4 79.5 -8.4 150 0.8
7750 18.9 66.0 170 6 3 6.1 3.4 26.1 79.0 -8.8 130 0.7
7500 19.3 66.7 160 7 3 4.7 2.6 25.8 78.4 -9.1 110 0.6
7250 19.5 67.1 155 8 4 3.2 1.8 25.3 77.6 -9.6 96 0.5
7000 19.7 67.5 155 8 4 3.9 2.1 24.9 76.7 -10.2 82 0.4
6750 20.0 68.0 150 8 4 2.2 1.2 24.4 75.9 -10.7 67 0.3
6500 20.0 68.0 145 8 4 -2.3 -1.3 23.6 74.6 -11.5 60 0.3
6250 19.6 67.3 135 8 4 -6.4 -3.5 22.6 72.6 -12.6 64 0.3
6000 19.3 66.7 130 8 4 2.8 1.6 21.6 70.8 -13.6 66 0.3
5750 19.6 67.3 125 7 4 -4.6 -2.5 21.1 70.0 -14.1 50 0.3
5500 M M M M M M M M M M M M
5250 M M M M M M M M M M M M
5000 M M M M M M M M M M M M
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
07/24/2025 AT 0900 MDT | 07/24/2025 AT 1200 MDT
|
CAPE... 0.0 LI... +1.1 | CAPE... +3.7 LI... +0.9
CINH... -0.3 K INDEX... +20.9 | CINH... -0.6 K INDEX... +18.6
|
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 -59.9 -75.8 215 21 11 1.6 0.9 | -59.5 -75.1 205 23 12 1.9 1.0
45000 -57.2 -71.0 205 36 19 2.0 1.1 | -56.7 -70.1 200 40 21 1.9 1.0
40000 -53.4 -64.1 200 60 31 6.5 3.5 | -53.2 -63.8 200 62 32 6.5 3.6
38000 -49.4 -56.9 200 56 29 6.6 3.6 | -49.2 -56.6 200 60 31 6.6 3.6
36000 -45.5 -49.9 200 52 27 6.4 3.5 | -44.8 -48.6 200 58 30 6.7 3.7
34000 -41.0 -41.8 205 43 22 7.6 4.2 | -40.6 -41.1 200 48 24 7.0 3.8
32000 -36.5 -33.7 205 32 17 7.5 4.1 | -36.4 -33.5 200 37 19 6.9 3.8
30000 -31.8 -25.2 205 28 15 7.9 4.3 | -31.8 -25.2 200 32 17 7.8 4.3
29000 -29.4 -20.9 205 27 14 7.9 4.3 | -29.5 -21.1 200 31 16 7.8 4.3
28000 -26.5 -15.7 210 25 13 7.3 4.0 | -27.2 -17.0 200 29 15 7.4 4.1
27000 -24.3 -11.7 210 24 12 7.3 4.0 | -25.0 -13.0 200 28 14 7.2 4.0
26000 -22.1 -7.8 210 22 11 7.3 4.0 | -22.8 -9.0 195 27 14 7.2 4.0
25000 -19.9 -3.8 210 20 10 6.6 3.6 | -20.7 -5.3 195 26 13 7.1 3.9
24000 -18.1 -0.6 210 19 10 5.8 3.2 | -19.0 -2.2 195 24 12 5.3 2.9
23000 -16.4 2.5 210 18 9 5.9 3.2 | -17.5 0.5 195 23 12 5.3 2.9
22000 -14.6 5.7 215 17 9 6.3 3.4 | -15.4 4.3 195 21 11 7.2 3.9
21000 -12.7 9.1 215 17 9 6.6 3.6 | -13.3 8.1 200 19 10 7.5 4.1
20000 -10.8 12.6 215 17 9 6.8 3.7 | -11.1 12.0 205 18 9 7.6 4.2
19500 -9.8 14.4 215 18 9 6.8 3.7 | -10.0 14.0 210 17 9 7.6 4.1
19000 -8.9 16.0 210 18 9 6.5 3.6 | -8.9 16.0 210 17 9 7.4 4.1
18500 -8.0 17.6 205 18 9 6.6 3.6 | -7.9 17.8 215 17 8 7.4 4.1
18000 -7.0 19.4 205 18 9 8.2 4.5 | -6.8 19.8 215 16 8 7.9 4.3
17500 -5.8 21.6 200 17 9 8.6 4.7 | -5.6 21.9 215 16 8 8.0 4.4
17000 -4.6 23.7 200 16 8 8.7 4.8 | -4.5 23.9 215 15 8 8.4 4.6
16500 -3.3 26.1 200 15 8 8.7 4.8 | -3.1 26.4 215 15 8 9.1 5.0
16000 -2.0 28.4 200 15 8 8.7 4.8 | -1.8 28.8 215 14 7 9.1 5.0
15500 -0.7 30.7 200 14 7 8.9 4.9 | -0.4 31.3 215 14 7 9.0 4.9
15000 0.7 33.3 200 13 7 8.9 4.9 | 0.9 33.6 215 13 7 9.0 4.9
14500 2.0 35.6 205 12 6 9.1 5.0 | 2.3 36.1 215 13 7 9.3 5.1
14000 3.4 38.1 205 12 6 9.1 5.0 | 3.7 38.7 220 12 6 9.3 5.1
13500 4.8 40.6 210 11 6 9.1 5.0 | 5.1 41.2 220 12 6 9.2 5.1
13000 6.1 43.0 210 11 6 9.0 4.9 | 6.5 43.7 225 12 6 9.2 5.0
12500 7.5 45.5 215 10 5 8.9 4.9 | 7.8 46.0 225 11 6 9.3 5.1
12000 8.9 48.0 220 10 5 8.8 4.8 | 9.2 48.6 230 11 6 9.4 5.1
11500 10.2 50.4 225 10 5 8.7 4.8 | 10.6 51.1 230 10 5 9.3 5.1
11000 11.5 52.7 225 9 5 8.3 4.6 | 12.0 53.6 235 10 5 9.0 4.9
10500 12.8 55.0 225 9 5 6.2 3.4 | 13.4 56.1 235 10 5 6.2 3.4
10250 13.2 55.8 230 8 4 6.4 3.5 | 13.7 56.7 240 9 5 6.9 3.8
10000 13.8 56.8 230 8 4 9.4 5.2 | 14.5 58.1 240 9 5 11.2 6.1
9750 14.5 58.1 230 8 4 8.7 4.8 | 15.3 59.5 245 9 5 10.4 5.7
9500 15.1 59.2 230 8 4 8.8 4.8 | 16.0 60.8 245 9 4 9.4 5.1
9250 16.4 61.5 230 7 4 7.5 4.1 | 16.7 62.1 250 8 4 8.1 4.4
9000 16.9 62.4 230 7 4 7.4 4.0 | 17.3 63.1 255 8 4 9.2 5.1
8750 17.4 63.3 225 7 4 6.8 3.8 | 18.0 64.4 255 8 4 9.9 5.4
8500 17.9 64.2 225 7 3 5.6 3.1 | 18.7 65.7 255 8 4 8.9 4.9
8250 18.3 64.9 220 6 3 6.3 3.5 | 19.3 66.7 260 7 4 7.3 4.0
8000 18.8 65.8 215 5 3 8.0 4.4 | 20.7 69.3 265 7 4 11.9 6.5
7750 19.4 66.9 205 5 3 6.5 3.6 | 21.5 70.7 260 7 4 9.8 5.3
7500 19.7 67.5 200 4 2 4.6 2.5 | 22.2 72.0 265 7 4 8.0 4.4
7250 20.1 68.2 200 3 2 6.0 3.3 | 22.8 73.0 270 7 3 9.5 5.2
7000 20.6 69.1 190 3 2 9.3 5.1 | 23.6 74.5 270 7 3 12.0 6.6
6750 21.4 70.5 185 3 2 9.2 5.0 | 24.5 76.1 265 7 3 11.2 6.1
6500 21.9 71.4 175 3 2 7.7 4.2 | 25.3 77.5 270 7 3 10.5 5.8
6250 22.5 72.5 165 3 1 7.2 4.0 | 26.1 79.0 275 7 3 8.9 4.9
6000 23.0 73.4 155 3 1 11.1 6.1 | 26.8 80.2 275 6 3 15.4 8.4
5750 24.2 75.6 160 2 1 21.0 11.5 | 28.6 83.5 275 6 3 33.2 18.2
5500 25.5 77.9 140 2 1 6.0 3.3 | 30.7 87.3 285 6 3 7.7 4.2
5250 M M M M M M M | M M M M M M M
5000 M M M M M M M | M M M M M M M
07/24/2025 AT 1500 MDT | 07/24/2025 AT 1800 MDT
|
CAPE... +12.0 LI... +0.5 | CAPE... +0.5 LI... +0.4
CINH... -3.9 K INDEX... +19.4 | CINH... -5.7 K INDEX... +19.0
|
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 -59.6 -75.3 195 26 13 2.2 1.2 | -59.7 -75.5 200 28 14 2.7 1.5
45000 -56.5 -69.7 200 42 21 1.6 0.9 | -56.3 -69.3 195 42 22 1.2 0.7
40000 -53.4 -64.1 195 61 32 6.8 3.7 | -53.7 -64.7 190 56 29 6.8 3.8
38000 -48.8 -55.8 195 58 30 6.8 3.8 | -49.0 -56.2 190 53 27 6.9 3.8
36000 -44.7 -48.5 195 56 29 6.9 3.8 | -44.8 -48.6 185 50 26 7.0 3.8
34000 -40.4 -40.7 200 49 25 7.2 3.9 | -40.4 -40.7 195 44 23 7.4 4.1
32000 -36.1 -33.0 205 43 22 7.1 3.9 | -36.0 -32.8 205 39 20 7.3 4.0
30000 -31.5 -24.7 205 39 20 7.7 4.2 | -31.4 -24.5 210 36 19 7.7 4.2
29000 -29.2 -20.6 200 38 19 7.7 4.2 | -29.1 -20.4 215 35 18 7.7 4.2
28000 -27.0 -16.6 200 36 19 7.1 3.9 | -26.9 -16.4 215 33 17 7.3 4.0
27000 -24.9 -12.8 200 35 18 6.9 3.8 | -24.7 -12.5 215 33 17 7.2 3.9
26000 -22.8 -9.0 200 34 18 6.9 3.8 | -22.6 -8.7 215 32 17 7.2 3.9
25000 -20.8 -5.4 195 33 17 6.8 3.7 | -20.4 -4.7 215 32 17 7.1 3.9
24000 -19.1 -2.4 195 31 16 5.5 3.0 | -18.5 -1.3 210 31 16 6.2 3.4
23000 -17.1 1.2 195 29 15 5.6 3.1 | -16.3 2.7 205 31 16 6.3 3.4
22000 -15.4 4.3 195 27 14 7.5 4.1 | -14.4 6.1 205 30 15 7.0 3.8
21000 -13.1 8.4 195 23 12 7.9 4.3 | -12.4 9.7 200 26 13 7.2 4.0
20000 -10.8 12.6 200 20 10 8.0 4.4 | -10.3 13.5 200 22 11 7.4 4.1
19500 -9.6 14.7 200 18 9 8.1 4.5 | -9.3 15.3 200 20 10 7.8 4.3
19000 -8.4 16.9 200 17 9 8.4 4.6 | -8.0 17.6 200 18 9 8.7 4.8
18500 -7.2 19.0 200 15 8 8.4 4.6 | -6.8 19.8 200 16 8 8.7 4.8
18000 -6.0 21.2 205 14 7 8.7 4.7 | -5.5 22.1 205 14 7 8.8 4.8
17500 -4.7 23.5 210 13 7 8.7 4.8 | -4.2 24.4 210 12 6 8.8 4.8
17000 -3.4 25.9 210 12 6 8.8 4.8 | -2.9 26.8 215 11 6 8.9 4.9
16500 -2.1 28.2 215 12 6 9.0 4.9 | -1.5 29.3 220 10 5 8.9 4.9
16000 -0.7 30.7 220 11 6 9.0 4.9 | -0.2 31.6 225 10 5 8.9 4.9
15500 0.6 33.1 220 11 6 9.2 5.1 | 1.2 34.2 230 9 5 9.2 5.0
15000 2.0 35.6 225 11 5 9.2 5.0 | 2.5 36.5 235 9 5 9.2 5.0
14500 3.4 38.1 230 10 5 9.3 5.1 | 3.9 39.0 240 9 5 9.5 5.2
14000 4.8 40.6 230 10 5 9.3 5.1 | 5.3 41.5 245 9 5 9.5 5.2
13500 6.2 43.2 235 10 5 9.3 5.1 | 6.8 44.2 250 10 5 9.4 5.1
13000 7.6 45.7 240 10 5 9.3 5.1 | 8.2 46.8 255 10 5 9.3 5.1
12500 8.9 48.0 245 10 5 9.4 5.1 | 9.5 49.1 260 10 5 9.3 5.1
12000 10.4 50.7 245 10 5 9.5 5.2 | 11.0 51.8 265 11 6 9.4 5.2
11500 11.8 53.2 250 10 5 9.5 5.2 | 12.4 54.3 265 11 6 9.3 5.1
11000 13.2 55.8 255 10 5 9.2 5.1 | 13.7 56.7 270 12 6 8.8 4.8
10500 14.6 58.3 260 10 5 6.8 3.7 | 15.0 59.0 275 13 6 11.0 6.1
10250 15.0 59.0 265 10 5 7.5 4.1 | 15.9 60.6 270 13 6 11.5 6.3
10000 15.8 60.4 265 10 5 11.2 6.2 | 16.6 61.9 270 13 7 8.7 4.8
9750 16.6 61.9 265 10 5 10.4 5.7 | 17.3 63.1 270 13 7 9.5 5.2
9500 17.4 63.3 265 10 5 10.0 5.5 | 18.0 64.4 270 13 7 9.1 5.0
9250 18.1 64.6 270 10 5 9.4 5.1 | 18.7 65.7 275 14 7 9.0 4.9
9000 18.8 65.8 270 10 5 9.9 5.4 | 19.4 66.9 275 14 7 9.3 5.1
8750 19.6 67.3 270 10 5 10.3 5.7 | 20.8 69.4 275 14 7 9.3 5.1
8500 20.3 68.5 270 10 5 9.6 5.3 | 21.4 70.5 275 14 7 8.0 4.4
8250 21.6 70.9 280 11 5 9.8 5.4 | 22.0 71.6 280 14 7 9.3 5.1
8000 22.5 72.5 275 11 5 12.2 6.7 | 22.8 73.0 280 14 7 11.2 6.1
7750 23.3 73.9 275 11 5 9.9 5.4 | 23.6 74.5 280 13 7 9.8 5.4
7500 24.0 75.2 275 11 6 7.6 4.2 | 24.3 75.7 280 14 7 8.1 4.5
7250 24.6 76.3 280 11 6 9.2 5.1 | 24.9 76.8 280 14 7 8.9 4.9
7000 25.4 77.7 280 11 6 12.1 6.6 | 25.6 78.1 280 14 7 11.6 6.3
6750 26.3 79.3 275 11 5 11.6 6.4 | 26.5 79.7 280 13 7 11.2 6.1
6500 27.1 80.8 280 11 6 10.8 5.9 | 27.3 81.1 280 13 7 10.1 5.6
6250 27.9 82.2 285 11 6 9.4 5.1 | 28.1 82.6 285 13 7 9.8 5.4
6000 28.7 83.7 285 11 5 14.3 7.9 | 28.8 83.8 285 13 7 10.6 5.8
5750 30.3 86.5 280 10 5 31.0 17.0 | 29.8 85.6 280 11 6 17.6 9.7
5500 32.6 90.7 290 10 5 20.7 11.3 | 31.5 88.7 285 11 6 28.3 15.5
5250 M M M M M M M | M M M M M M M
5000 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 AT WALKER FIELD IN GRAND
JUNCTION, COLORADO AT
NORTH LATITUDE: 39 DEG 07 MIN 00.001 SEC
WEST LONGITUDE: 108 DEG 31 MIN 59.998 SEC
ELEVATION: 4839 FEET (1475 METERS)
AND MAY NOT BE REPRESENTATIVE OF OTHER AREAS ALONG THE WESTERN SLOPE OF
COLORADO. 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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