758
UXUS97 KGJT 121307
SRGGJT
SOARING FORECAST
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO
707 AM MDT SUNDAY, JULY 12, 2026
THIS FORECAST IS FOR SUNDAY, JULY 12, 2026:
IF THE TRIGGER TEMPERATURE OF 86.5 F/30.3 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1933 FT/MIN (9.8 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 23938 FT MSL (18329 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 104.0 F/40.5 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................. 20288 FT MSL (14679 FT AGL)
THERMAL SOARING OUTLOOK FOR MONDAY 07/13....... EXCELLENT
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 05:58:41 / 20:41:01 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 42 MIN 19 SEC (882 MIN 19 SEC)
ALTITUDE OF SUN AT 13:19:51 MDT... 72.25 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 07/12/2026 AT 0600 MDT
FREEZING LEVEL.................. 17146 FT MSL (11537 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 17794 FT MSL (12185 FT AGL)
LIFTED CONDENSATION LEVEL....... 19904 FT MSL (14295 FT AGL)
LIFTED INDEX.................... -5.3
K INDEX......................... +28.1
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 -64.6 -84.3 165 20 10 4.4 2.4 M M M M M
45000 -57.0 -70.6 160 21 11 6.0 3.3 M M M M M
40000 -47.1 -52.8 170 15 8 7.2 3.9 M M M M M
38000 -42.8 -45.0 165 13 6 7.2 3.9 M M M M M
36000 -38.4 -37.1 160 10 5 8.0 4.4 M M M M M
34000 -33.6 -28.5 150 12 6 7.9 4.3 M M M M M
32000 -28.9 -20.0 140 13 7 7.3 4.0 53.5 128.2 10.1 M M
30000 -24.8 -12.6 140 10 5 6.9 3.8 51.0 123.8 8.5 M M
29000 -22.7 -8.9 145 8 4 6.9 3.8 50.0 122.0 7.8 M M
28000 -21.0 -5.8 140 7 4 3.1 1.7 48.5 119.3 6.7 M M
27000 -20.0 -4.0 125 7 3 3.4 1.9 46.0 114.8 4.7 M M
26000 -19.0 -2.2 110 7 4 3.5 1.9 43.6 110.6 2.8 M M
25000 -18.0 -0.4 095 8 4 5.8 3.2 41.5 106.7 1.0 M M
24000 -15.8 3.6 085 8 4 7.2 3.9 40.5 104.8 0.1 M M
23000 -13.7 7.3 075 8 4 7.2 4.0 39.5 103.2 -0.7 1656 8.4
22000 -11.1 12.0 070 9 5 7.2 4.0 38.5 101.2 -1.6 1539 7.8
21000 -8.9 16.0 065 11 5 7.3 4.0 37.5 99.6 -2.5 1445 7.3
20000 -6.8 19.8 065 12 6 7.2 4.0 36.7 98.1 -3.3 1352 6.9
19500 -5.7 21.7 065 12 6 8.4 4.6 36.4 97.5 -3.6 1303 6.6
19000 -4.4 24.1 060 11 6 8.7 4.7 36.2 97.1 -3.8 1250 6.3
18500 -3.1 26.4 055 10 5 8.6 4.7 36.0 96.8 -4.0 1197 6.1
18000 -1.9 28.6 055 8 4 8.1 4.4 35.7 96.3 -4.3 1145 5.8
17500 -0.7 30.7 045 6 3 8.2 4.5 35.5 95.8 -4.6 1095 5.6
17000 0.4 32.7 035 4 2 7.8 4.3 35.2 95.3 -4.9 1046 5.3
16500 1.5 34.7 005 2 1 7.7 4.2 34.8 94.7 -5.4 999 5.1
16000 2.6 36.7 305 2 1 7.9 4.3 34.5 94.1 -5.8 951 4.8
15500 3.7 38.7 275 4 2 8.1 4.4 34.2 93.6 -6.1 902 4.6
15000 4.9 40.8 265 5 3 8.1 4.4 33.9 93.1 -6.5 853 4.3
14500 6.1 43.0 260 7 4 7.9 4.4 33.6 92.6 -6.8 803 4.1
14000 7.3 45.1 255 8 4 7.9 4.4 33.3 92.0 -7.1 752 3.8
13500 8.5 47.3 255 9 5 8.3 4.5 33.1 91.5 -7.4 701 3.6
13000 9.7 49.5 250 10 5 8.3 4.6 32.8 91.1 -7.7 649 3.3
12500 11.0 51.8 250 11 6 8.7 4.8 32.6 90.8 -7.9 597 3.0
12000 12.3 54.1 245 13 6 8.9 4.9 32.5 90.5 -8.1 543 2.8
11500 13.6 56.5 240 14 7 8.2 4.5 32.4 90.3 -8.3 489 2.5
11000 14.7 58.5 235 15 8 7.2 3.9 32.0 89.7 -8.7 440 2.2
10500 16.0 60.8 230 16 8 9.9 5.4 31.9 89.5 -8.8 385 2.0
10250 16.7 62.1 225 17 9 8.0 4.4 31.8 89.3 -9.0 359 1.8
10000 17.3 63.1 225 17 9 8.2 4.5 31.7 89.1 -9.1 334 1.7
9750 17.9 64.2 220 18 9 8.7 4.7 31.6 88.9 -9.3 308 1.6
9500 18.5 65.3 220 18 9 6.6 3.6 31.5 88.7 -9.4 283 1.4
9250 18.9 66.0 215 19 10 6.3 3.4 31.1 88.1 -9.7 263 1.3
9000 19.5 67.1 210 19 10 8.1 4.4 31.0 87.8 -9.9 238 1.2
8750 20.0 68.0 210 19 10 7.6 4.2 30.8 87.5 -10.1 214 1.1
8500 20.6 69.1 205 19 10 7.5 4.1 30.7 87.2 -10.3 190 1.0
8250 21.1 70.0 205 19 10 6.6 3.6 30.5 86.8 -10.5 167 0.8
8000 21.6 70.9 200 19 10 6.2 3.4 30.2 86.3 -10.8 145 0.7
7750 22.0 71.6 195 18 9 6.1 3.4 29.9 85.9 -11.1 124 0.6
7500 22.5 72.5 190 17 9 5.1 2.8 29.6 85.3 -11.4 104 0.5
7250 22.8 73.0 185 17 9 4.3 2.3 29.2 84.6 -11.9 86 0.4
7000 23.1 73.6 180 16 8 5.0 2.8 28.8 83.9 -12.3 69 0.3
6750 23.5 74.3 175 14 7 2.7 1.5 28.4 83.2 -12.7 51 0.3
6500 23.5 74.3 170 13 7 -1.2 -0.6 27.7 81.9 -13.4 43 0.2
6250 23.4 74.1 160 12 6 -2.1 -1.2 26.8 80.3 -14.3 39 0.2
6000 23.3 73.9 150 11 6 0.8 0.4 26.0 78.8 -15.1 34 0.2
5750 23.3 73.9 140 9 5 -7.3 -4.0 25.2 77.4 -16.0 28 0.1
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 * * * * * *
07/12/2026 AT 0900 MDT | 07/12/2026 AT 1200 MDT
|
CAPE... +10.6 LI... +0.5 | CAPE... +126.9 LI... +0.3
CINH... -69.4 K INDEX... +16.3 | CINH... -46.0 K INDEX... +14.3
|
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 -64.9 -84.8 190 12 6 4.1 2.3 | -65.3 -85.5 170 13 7 4.3 2.4
45000 -56.9 -70.4 195 12 6 7.0 3.8 | -57.0 -70.6 170 11 6 7.2 4.0
40000 -46.5 -51.7 150 5 3 5.5 3.0 | -46.4 -51.5 140 11 6 5.1 2.8
38000 -43.2 -45.8 125 8 4 5.5 3.0 | -43.3 -45.9 135 13 6 5.1 2.8
36000 -39.7 -39.5 110 11 6 8.0 4.4 | -40.0 -40.0 125 13 7 8.4 4.6
34000 -35.0 -31.0 070 10 5 7.7 4.2 | -35.2 -31.4 095 12 6 8.1 4.4
32000 -30.4 -22.7 035 14 7 7.9 4.4 | -30.4 -22.7 065 14 7 7.9 4.3
30000 -25.9 -14.6 025 14 7 7.5 4.1 | -26.0 -14.8 055 14 7 7.2 3.9
29000 -23.7 -10.7 025 14 7 7.4 4.1 | -23.9 -11.0 050 14 7 7.2 3.9
28000 -21.9 -7.4 020 14 7 2.8 1.6 | -22.1 -7.8 050 14 7 3.6 2.0
27000 -20.9 -5.6 030 13 7 3.1 1.7 | -20.9 -5.6 060 14 7 3.8 2.1
26000 -20.0 -4.0 040 12 6 3.2 1.7 | -19.8 -3.6 070 15 8 3.8 2.1
25000 -19.0 -2.2 045 12 6 5.5 3.0 | -18.6 -1.5 075 15 8 5.8 3.2
24000 -16.4 2.5 065 12 6 6.8 3.7 | -16.0 3.2 085 15 8 6.8 3.7
23000 -14.4 6.1 080 12 6 6.8 3.7 | -14.0 6.8 090 15 8 6.8 3.7
22000 -12.2 10.0 090 13 7 8.4 4.6 | -11.8 10.8 095 15 8 8.7 4.8
21000 -9.7 14.5 090 12 6 8.4 4.6 | -9.2 15.4 095 13 7 8.6 4.7
20000 -7.2 19.0 095 11 6 8.5 4.7 | -6.6 20.1 095 12 6 8.6 4.7
19500 -6.0 21.2 095 11 6 8.7 4.8 | -5.4 22.3 095 11 5 8.4 4.6
19000 -4.7 23.5 095 11 5 8.8 4.8 | -4.1 24.6 095 10 5 8.4 4.6
18500 -3.4 25.9 095 10 5 8.9 4.9 | -2.9 26.8 100 9 4 8.4 4.6
18000 -2.1 28.2 100 10 5 9.2 5.0 | -1.7 28.9 100 8 4 8.3 4.5
17500 -0.8 30.6 100 10 5 9.2 5.0 | -0.5 31.1 100 7 4 8.3 4.6
17000 0.6 33.1 105 10 5 9.0 4.9 | 0.7 33.3 100 6 3 9.0 4.9
16500 1.9 35.4 110 10 5 9.0 4.9 | 2.0 35.6 105 6 3 9.1 5.0
16000 3.2 37.8 110 10 5 9.0 4.9 | 3.4 38.1 110 5 3 9.1 5.0
15500 4.5 40.1 115 10 5 8.9 4.9 | 4.7 40.5 120 5 3 9.0 5.0
15000 5.8 42.4 120 10 5 8.9 4.9 | 6.0 42.8 130 5 3 9.1 5.0
14500 7.1 44.8 125 10 5 8.7 4.8 | 7.3 45.1 140 5 3 8.9 4.9
14000 8.4 47.1 130 9 5 8.8 4.8 | 8.6 47.5 150 5 3 9.0 4.9
13500 9.6 49.3 135 9 5 8.4 4.6 | 10.0 50.0 160 6 3 9.1 5.0
13000 10.8 51.4 145 9 4 8.4 4.6 | 11.3 52.3 165 6 3 9.1 5.0
12500 12.1 53.8 150 8 4 8.2 4.5 | 12.6 54.7 170 6 3 9.1 5.0
12000 13.2 55.8 160 9 4 8.2 4.5 | 14.0 57.2 170 6 3 9.1 5.0
11500 14.4 57.9 170 9 5 8.0 4.4 | 15.3 59.5 175 7 3 9.1 5.0
11000 15.6 60.1 175 10 5 7.9 4.3 | 16.6 61.9 175 6 3 9.0 4.9
10500 16.7 62.1 180 10 5 7.0 3.8 | 17.9 64.2 180 6 3 7.9 4.3
10250 17.2 63.0 180 11 6 6.9 3.8 | 18.5 65.3 180 6 3 7.9 4.4
10000 17.7 63.9 180 11 6 8.0 4.4 | 19.1 66.4 180 6 3 9.5 5.2
9750 18.3 64.9 180 11 6 7.7 4.2 | 19.8 67.6 180 6 3 9.0 4.9
9500 18.9 66.0 180 11 6 7.8 4.3 | 20.4 68.7 180 6 3 9.7 5.3
9250 19.4 66.9 180 12 6 7.4 4.1 | 21.2 70.2 180 5 3 9.5 5.2
9000 19.9 67.8 180 12 6 6.6 3.6 | 21.8 71.2 180 5 2 8.4 4.6
8750 20.4 68.7 180 12 6 6.3 3.4 | 22.4 72.3 180 4 2 8.3 4.6
8500 21.3 70.3 175 12 6 6.1 3.4 | 23.0 73.4 180 4 2 8.2 4.5
8250 21.7 71.1 175 13 6 6.0 3.3 | 24.2 75.6 170 4 2 9.6 5.3
8000 22.1 71.8 175 11 6 5.6 3.1 | 25.0 77.0 170 3 2 11.2 6.1
7750 22.5 72.5 170 11 5 4.5 2.5 | 25.7 78.3 170 3 2 9.2 5.0
7500 22.8 73.0 165 11 5 3.6 2.0 | 26.3 79.3 165 3 2 7.6 4.2
7250 23.1 73.6 160 11 5 4.6 2.5 | 27.0 80.6 160 3 2 9.7 5.3
7000 23.6 74.5 155 9 5 6.6 3.6 | 27.8 82.0 160 3 1 12.5 6.9
6750 24.1 75.4 150 8 4 7.1 3.9 | 28.7 83.7 160 3 1 11.3 6.2
6500 24.6 76.3 150 8 4 6.6 3.6 | 29.5 85.1 155 3 1 10.8 5.9
6250 25.1 77.2 140 8 4 7.0 3.8 | 30.3 86.5 150 3 1 8.8 4.8
6000 25.8 78.4 140 6 3 12.4 6.8 | 31.0 87.8 155 2 1 14.6 8.0
5750 27.0 80.6 135 6 3 20.6 11.3 | 32.7 90.9 155 2 1 32.3 17.7
5500 28.3 82.9 130 6 3 6.2 3.4 | 34.7 94.5 145 2 1 7.6 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
07/12/2026 AT 1500 MDT | 07/12/2026 AT 1800 MDT
|
CAPE... +34.2 LI... -0.2 | CAPE... +3.7 LI... +0.1
CINH... -16.7 K INDEX... +9.5 | CINH... -10.8 K INDEX... +10.5
|
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 -65.1 -85.2 155 18 9 4.4 2.4 | -65.3 -85.5 160 23 12 4.8 2.6
45000 -56.9 -70.4 150 16 8 6.8 3.8 | -56.9 -70.4 160 21 11 6.7 3.7
40000 -46.5 -51.7 155 12 6 5.9 3.3 | -46.4 -51.5 165 11 5 6.2 3.4
38000 -42.9 -45.2 145 11 5 5.9 3.3 | -42.7 -44.9 160 9 5 6.2 3.4
36000 -39.2 -38.6 130 9 5 7.4 4.0 | -38.8 -37.8 150 8 4 7.4 4.1
34000 -34.9 -30.8 100 12 6 7.2 4.0 | -34.5 -30.1 115 10 5 7.3 4.0
32000 -30.5 -22.9 085 16 8 7.7 4.2 | -30.1 -22.2 090 14 7 7.2 3.9
30000 -26.1 -15.0 080 15 8 7.4 4.1 | -26.1 -15.0 085 14 7 6.7 3.7
29000 -23.9 -11.0 080 15 8 7.4 4.1 | -24.1 -11.4 080 14 7 6.7 3.7
28000 -21.9 -7.4 080 14 7 4.3 2.4 | -22.3 -8.1 080 14 7 4.1 2.3
27000 -20.6 -5.1 085 14 7 4.5 2.5 | -21.1 -6.0 085 13 7 4.3 2.4
26000 -18.9 -2.0 100 13 7 4.6 2.5 | -19.8 -3.6 095 12 6 4.4 2.4
25000 -17.4 0.7 105 13 7 6.4 3.5 | -17.9 -0.2 100 11 6 7.5 4.1
24000 -15.6 3.9 110 12 6 6.2 3.4 | -15.8 3.6 100 11 6 7.3 4.0
23000 -13.7 7.3 120 11 6 6.2 3.4 | -13.6 7.5 100 11 5 7.4 4.0
22000 -11.7 10.9 125 11 5 8.6 4.7 | -11.3 11.7 095 10 5 8.9 4.9
21000 -9.1 15.6 120 9 5 8.5 4.7 | -8.7 16.3 095 9 4 8.8 4.8
20000 -6.6 20.1 120 8 4 8.4 4.6 | -6.0 21.2 095 7 4 8.8 4.8
19500 -5.3 22.5 115 7 4 9.2 5.1 | -4.7 23.5 090 7 4 9.1 5.0
19000 -3.9 25.0 115 7 3 9.3 5.1 | -3.3 26.1 090 7 3 9.1 5.0
18500 -2.5 27.5 115 6 3 9.3 5.1 | -2.0 28.4 090 6 3 9.1 5.0
18000 -1.2 29.8 110 6 3 9.2 5.1 | -0.6 30.9 090 6 3 9.2 5.1
17500 0.2 32.4 110 5 3 9.2 5.1 | 0.8 33.4 090 6 3 9.2 5.1
17000 1.6 34.9 105 5 2 9.2 5.1 | 2.2 36.0 090 5 3 9.5 5.2
16500 3.0 37.4 105 4 2 9.2 5.1 | 3.6 38.5 090 5 3 9.6 5.3
16000 4.4 39.9 105 4 2 9.2 5.1 | 5.0 41.0 090 5 3 9.5 5.2
15500 5.7 42.3 100 4 2 9.2 5.0 | 6.4 43.5 090 5 2 9.4 5.1
15000 7.1 44.8 100 3 2 9.2 5.0 | 7.8 46.0 090 5 2 9.4 5.1
14500 8.5 47.3 095 3 2 9.3 5.1 | 9.2 48.6 090 4 2 9.4 5.2
14000 9.8 49.6 095 3 1 9.3 5.1 | 10.6 51.1 095 4 2 9.4 5.2
13500 11.2 52.2 090 3 1 9.5 5.2 | 12.1 53.8 095 4 2 9.5 5.2
13000 12.6 54.7 090 2 1 9.5 5.2 | 13.5 56.3 100 4 2 9.5 5.2
12500 14.0 57.2 085 2 1 9.5 5.2 | 14.9 58.8 100 4 2 9.5 5.2
12000 15.4 59.7 080 2 1 9.5 5.2 | 16.3 61.3 105 4 2 9.4 5.2
11500 16.8 62.2 080 2 1 9.4 5.2 | 17.7 63.9 105 3 2 9.0 4.9
11000 18.2 64.8 075 3 1 9.2 5.0 | 19.0 66.2 110 3 2 8.5 4.7
10500 19.6 67.3 075 3 1 7.5 4.1 | 20.2 68.4 115 3 2 11.3 6.2
10250 20.1 68.2 080 2 1 8.1 4.5 | 21.2 70.2 115 3 1 12.1 6.6
10000 20.8 69.4 075 2 1 10.8 5.9 | 21.9 71.4 115 3 1 8.8 4.8
9750 21.6 70.9 070 2 1 10.3 5.6 | 22.6 72.7 115 2 1 9.9 5.4
9500 22.4 72.3 070 3 1 9.7 5.3 | 23.3 73.9 115 2 1 8.6 4.7
9250 23.0 73.4 070 2 1 9.3 5.1 | 23.9 75.0 120 2 1 8.9 4.9
9000 24.5 76.1 060 2 1 10.2 5.6 | 24.6 76.3 120 2 1 10.2 5.6
8750 25.2 77.4 060 2 1 9.3 5.1 | 25.4 77.7 125 2 1 10.2 5.6
8500 25.8 78.4 055 2 1 8.0 4.4 | 26.8 80.2 130 2 1 8.2 4.5
8250 26.5 79.7 055 2 1 10.0 5.5 | 27.4 81.3 130 2 1 9.7 5.3
8000 27.3 81.1 050 2 1 12.1 6.7 | 28.2 82.8 135 2 1 11.5 6.3
7750 28.2 82.8 050 2 1 10.0 5.5 | 29.0 84.2 145 1 1 9.7 5.3
7500 28.8 83.8 045 2 1 7.8 4.3 | 29.7 85.5 145 1 1 7.5 4.1
7250 29.5 85.1 045 2 1 9.7 5.3 | 30.3 86.5 150 1 1 9.2 5.0
7000 30.3 86.5 040 2 1 12.4 6.8 | 31.1 88.0 155 1 1 12.4 6.8
6750 31.2 88.2 040 2 1 11.5 6.3 | 32.0 89.6 170 1 1 11.2 6.2
6500 32.0 89.6 035 2 1 10.6 5.8 | 32.7 90.9 175 1 1 9.7 5.3
6250 32.8 91.0 035 2 1 9.4 5.1 | 33.5 92.3 175 1 1 9.5 5.2
6000 33.5 92.3 030 2 1 13.2 7.3 | 34.2 93.6 180 1 1 10.6 5.8
5750 35.1 95.2 030 2 1 28.6 15.7 | 35.2 95.4 185 1 0 17.9 9.8
5500 37.4 99.3 020 2 1 27.5 15.1 | 36.9 98.4 180 1 0 25.9 14.2
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
________________________________________________________________________________
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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