898
UXUS97 KGJT 301306
SRGGJT
SOARING FORECAST
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO
706 AM MDT TUESDAY, JUNE 30, 2026
THIS FORECAST IS FOR TUESDAY, JUNE 30, 2026:
IF THE TRIGGER TEMPERATURE OF 74.6 F/23.7 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1463 FT/MIN (7.4 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 21271 FT MSL (15664 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 89.0 F/32.1 C
TIME OF TRIGGER TEMPERATURE.................... 0915 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................. 18382 FT MSL (12775 FT AGL)
THERMAL SOARING OUTLOOK FOR WEDNESDAY 07/01.... EXCELLENT
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 05:51:35 / 20:44:13 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 52 MIN 37 SEC (892 MIN 37 SEC)
ALTITUDE OF SUN AT 13:17:54 MDT... 73.57 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 06/30/2026 AT 0600 MDT
FREEZING LEVEL.................. 14055 FT MSL (8448 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 20690 FT MSL (15083 FT AGL)
LIFTED CONDENSATION LEVEL....... 21245 FT MSL (15638 FT AGL)
LIFTED INDEX.................... -0.2
K INDEX......................... +10.2
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 -57.6 -71.7 230 43 22 2.5 1.4 M M M M M
45000 -54.2 -65.6 230 54 28 1.3 0.7 M M M M M
40000 -52.3 -62.1 225 57 29 1.5 0.8 M M M M M
38000 -50.2 -58.4 225 51 26 3.2 1.7 M M M M M
36000 -48.3 -54.9 225 44 23 3.2 1.7 M M M M M
34000 -45.0 -49.0 225 39 20 6.8 3.7 M M M M M
32000 -40.9 -41.6 225 36 18 6.8 3.7 M M M M M
30000 -36.4 -33.5 230 33 17 8.1 4.5 38.3 100.9 5.0 M M
29000 -33.9 -29.0 230 32 17 8.1 4.5 37.6 99.8 4.6 M M
28000 -31.5 -24.7 230 32 16 8.1 4.5 37.1 98.8 4.2 M M
27000 -29.1 -20.4 230 32 16 8.0 4.4 36.5 97.6 3.8 M M
26000 -26.7 -16.1 230 33 17 8.0 4.4 35.8 96.4 3.2 M M
25000 -24.3 -11.7 230 34 17 8.0 4.4 35.2 95.3 2.8 M M
24000 -22.0 -7.6 230 34 18 7.2 4.0 34.4 94.0 2.2 M M
23000 -19.8 -3.6 230 34 18 7.2 4.0 33.5 92.2 1.4 M M
22000 -17.6 0.3 230 34 18 7.2 4.0 32.6 90.7 0.7 M M
21000 -15.1 4.8 230 32 17 6.7 3.7 31.3 88.4 -0.4 1429 7.3
20000 -13.1 8.4 230 30 16 6.7 3.7 30.2 86.4 -1.4 1340 6.8
19500 -12.1 10.2 230 29 15 6.7 3.7 29.8 85.6 -1.8 1295 6.6
19000 -11.1 12.0 230 28 14 5.9 3.3 29.2 84.6 -2.3 1251 6.4
18500 -10.3 13.5 230 26 13 5.7 3.1 28.5 83.3 -2.9 1212 6.2
18000 -9.5 14.9 225 24 12 5.8 3.2 27.8 82.1 -3.6 1172 6.0
17500 -8.5 16.7 225 22 11 7.0 3.9 27.3 81.1 -4.1 1128 5.7
17000 -7.5 18.5 230 20 10 6.9 3.8 26.8 80.2 -4.6 1083 5.5
16500 -6.4 20.5 230 19 10 8.3 4.6 26.4 79.5 -5.0 1035 5.3
16000 -5.1 22.8 230 18 9 8.5 4.7 26.2 79.2 -5.2 982 5.0
15500 -3.9 25.0 230 17 9 8.8 4.8 26.0 78.8 -5.4 930 4.7
15000 -2.5 27.5 235 16 8 9.1 5.0 25.9 78.6 -5.6 875 4.4
14500 -1.2 29.8 235 16 8 9.1 5.0 25.8 78.4 -5.7 820 4.2
14000 0.2 32.4 235 15 8 9.2 5.0 25.7 78.2 -5.9 764 3.9
13500 1.6 34.9 240 14 7 9.2 5.1 25.6 78.0 -6.0 708 3.6
13000 2.9 37.2 240 13 7 9.0 4.9 25.5 77.9 -6.1 652 3.3
12500 4.3 39.7 235 12 6 9.0 5.0 25.4 77.7 -6.3 597 3.0
12000 5.6 42.1 235 11 6 9.2 5.0 25.3 77.5 -6.4 542 2.8
11500 7.0 44.6 230 10 5 9.3 5.1 25.2 77.3 -6.6 486 2.5
11000 8.3 46.9 225 9 5 7.7 4.2 25.0 76.9 -6.8 433 2.2
10500 9.4 48.9 215 8 4 9.6 5.3 24.6 76.3 -7.1 385 2.0
10250 10.2 50.4 210 8 4 10.1 5.6 24.7 76.5 -7.1 353 1.8
10000 10.8 51.4 200 8 4 6.7 3.7 24.6 76.2 -7.2 327 1.7
9750 11.3 52.3 195 7 4 6.4 3.5 24.3 75.8 -7.5 305 1.6
9500 11.8 53.2 185 7 4 7.0 3.9 24.1 75.3 -7.8 283 1.4
9250 12.3 54.1 180 7 4 7.3 4.0 23.9 75.0 -7.9 259 1.3
9000 12.8 55.0 175 7 4 6.4 3.5 23.7 74.6 -8.2 236 1.2
8750 13.3 55.9 165 7 3 6.0 3.3 23.4 74.1 -8.5 215 1.1
8500 13.8 56.8 160 7 3 6.4 3.5 23.1 73.6 -8.8 194 1.0
8250 14.2 57.6 155 7 3 5.0 2.7 22.8 73.1 -9.1 173 0.9
8000 14.5 58.1 155 7 4 3.7 2.0 22.4 72.2 -9.5 157 0.8
7750 14.8 58.6 150 7 3 4.2 2.3 21.9 71.5 -10.0 140 0.7
7500 15.1 59.2 145 7 3 3.9 2.2 21.5 70.7 -10.4 124 0.6
7250 15.4 59.7 140 7 3 2.8 1.5 21.0 69.8 -11.0 109 0.6
7000 15.5 59.9 140 7 3 0.5 0.3 20.4 68.7 -11.6 99 0.5
6750 15.5 59.9 135 6 3 0.4 0.2 19.7 67.4 -12.4 91 0.5
6500 15.4 59.7 130 6 3 -1.8 -1.0 18.9 66.1 -13.1 84 0.4
6250 15.1 59.2 120 6 3 -7.1 -3.9 17.8 64.1 -14.3 87 0.4
6000 14.7 58.5 110 6 3 -1.1 -0.6 16.7 62.0 -15.5 93 0.5
5750 14.6 58.3 105 6 3 -7.0 -3.8 15.9 60.6 -16.3 87 0.4
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 * * * * * *
06/30/2026 AT 0900 MDT | 06/30/2026 AT 1200 MDT
|
CAPE... 0.0 LI... +3.2 | CAPE... 0.0 LI... +1.8
CINH... -0.1 K INDEX... +8.0 | CINH... -0.2 K INDEX... +14.2
|
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 -58.1 -72.6 220 48 25 1.7 1.0 | -57.5 -71.5 215 48 25 2.1 1.2
45000 -55.4 -67.7 215 68 35 2.1 1.1 | -54.4 -65.9 215 69 35 1.8 1.0
40000 -52.0 -61.6 220 83 43 4.0 2.2 | -51.5 -60.7 215 82 42 3.3 1.8
38000 -49.3 -56.7 215 85 44 4.5 2.5 | -49.2 -56.6 215 84 43 3.8 2.1
36000 -46.7 -52.1 215 86 44 4.5 2.4 | -46.9 -52.4 215 86 44 3.8 2.1
34000 -43.4 -46.1 215 83 43 6.0 3.3 | -43.8 -46.8 215 82 42 6.0 3.3
32000 -39.8 -39.6 215 78 40 6.0 3.3 | -40.2 -40.4 215 76 39 6.0 3.3
30000 -35.9 -32.6 215 72 37 7.0 3.9 | -36.2 -33.2 215 70 36 7.2 4.0
29000 -33.7 -28.7 215 68 35 7.0 3.9 | -34.1 -29.4 215 67 35 7.2 4.0
28000 -31.6 -24.9 215 64 33 7.0 3.9 | -31.9 -25.4 215 65 33 7.2 4.0
27000 -29.5 -21.1 215 61 31 7.1 3.9 | -29.8 -21.6 210 63 32 7.1 3.9
26000 -27.4 -17.3 215 57 29 7.1 3.9 | -27.6 -17.7 210 61 31 7.1 3.9
25000 -25.3 -13.5 215 54 28 7.1 3.9 | -25.5 -13.9 210 59 31 7.1 3.9
24000 -22.7 -8.9 210 50 26 6.9 3.8 | -22.9 -9.2 210 57 29 6.8 3.7
23000 -20.6 -5.1 210 48 25 6.9 3.8 | -20.9 -5.6 210 54 28 6.8 3.8
22000 -18.5 -1.3 210 45 23 6.8 3.8 | -18.9 -2.0 210 52 27 6.8 3.7
21000 -16.3 2.7 210 43 22 7.8 4.3 | -16.7 1.9 210 49 25 7.6 4.1
20000 -14.0 6.8 205 42 21 7.8 4.3 | -14.4 6.1 210 46 24 7.6 4.2
19500 -12.8 9.0 205 41 21 7.8 4.3 | -13.3 8.1 210 44 23 7.6 4.2
19000 -11.7 10.9 205 40 20 7.7 4.2 | -12.2 10.0 210 43 22 7.4 4.0
18500 -10.5 13.1 205 38 20 7.7 4.2 | -11.1 12.0 210 40 21 7.3 4.0
18000 -9.4 15.1 205 37 19 7.7 4.2 | -10.0 14.0 210 38 19 7.3 4.0
17500 -8.2 17.2 205 36 18 7.7 4.2 | -9.0 15.8 210 35 18 7.5 4.1
17000 -7.1 19.2 205 34 18 7.7 4.2 | -7.9 17.8 210 33 17 7.5 4.1
16500 -6.0 21.2 205 33 17 8.0 4.4 | -6.8 19.8 210 30 16 7.8 4.3
16000 -4.8 23.4 205 31 16 8.1 4.4 | -5.6 21.9 210 28 15 7.9 4.3
15500 -3.6 25.5 205 30 16 8.2 4.5 | -4.5 23.9 210 26 13 8.2 4.5
15000 -2.4 27.7 205 29 15 8.4 4.6 | -3.2 26.2 210 25 13 8.7 4.8
14500 -1.2 29.8 210 28 14 8.4 4.6 | -1.9 28.6 210 23 12 8.8 4.8
14000 0.1 32.2 210 27 14 8.2 4.5 | -0.6 30.9 210 22 11 9.2 5.0
13500 1.3 34.3 210 26 13 8.2 4.5 | 0.8 33.4 210 21 11 9.1 5.0
13000 2.5 36.5 210 25 13 8.4 4.6 | 2.2 36.0 210 21 11 9.4 5.2
12500 3.8 38.8 210 24 12 8.4 4.6 | 3.6 38.5 210 20 10 9.4 5.2
12000 5.0 41.0 215 23 12 8.2 4.5 | 5.0 41.0 210 20 10 9.3 5.1
11500 6.2 43.2 215 22 11 8.2 4.5 | 6.4 43.5 210 19 10 9.4 5.2
11000 7.4 45.3 215 22 11 7.1 3.9 | 7.7 45.9 210 18 9 8.2 4.5
10500 8.4 47.1 220 21 11 6.2 3.4 | 8.9 48.0 215 17 9 7.7 4.2
10250 9.0 48.2 220 21 11 10.2 5.6 | 9.6 49.3 215 16 8 11.4 6.2
10000 9.9 49.8 215 20 11 10.9 6.0 | 10.5 50.9 215 17 9 11.8 6.5
9750 10.5 50.9 215 20 10 7.2 3.9 | 11.2 52.2 215 16 8 9.0 4.9
9500 11.1 52.0 215 20 10 8.5 4.6 | 12.0 53.6 215 16 8 10.0 5.5
9250 11.7 53.1 215 19 10 7.1 3.9 | 12.7 54.9 215 16 8 9.0 4.9
9000 12.2 54.0 215 19 10 7.1 3.9 | 13.3 55.9 215 15 8 9.5 5.2
8750 12.8 55.0 210 18 9 8.1 4.4 | 14.1 57.4 220 15 8 10.6 5.8
8500 13.9 57.0 205 17 9 7.1 3.9 | 15.7 60.3 220 15 8 9.8 5.4
8250 14.4 57.9 205 17 9 6.3 3.5 | 16.4 61.5 220 14 7 9.7 5.3
8000 14.9 58.8 200 16 8 7.2 3.9 | 17.1 62.8 220 14 7 10.4 5.7
7750 15.5 59.9 195 15 8 7.3 4.0 | 17.9 64.2 220 14 7 10.5 5.8
7500 16.0 60.8 190 15 8 5.5 3.0 | 18.7 65.7 220 14 7 9.0 5.0
7250 16.3 61.3 185 15 8 4.7 2.6 | 19.3 66.7 220 13 7 8.4 4.6
7000 16.8 62.2 180 14 7 8.2 4.5 | 20.0 68.0 220 13 7 10.7 5.9
6750 17.5 63.5 180 13 7 9.8 5.4 | 20.9 69.6 225 13 6 11.6 6.4
6500 18.2 64.8 175 12 6 9.1 5.0 | 21.7 71.1 225 12 6 11.1 6.1
6250 18.9 66.0 170 12 6 9.3 5.1 | 22.6 72.7 225 12 6 12.0 6.6
6000 19.5 67.1 165 12 6 8.3 4.6 | 23.4 74.1 225 11 6 7.8 4.3
5750 20.2 68.4 170 10 5 12.4 6.8 | 24.0 75.2 225 11 6 12.7 6.9
5500 22.2 72.0 160 9 5 47.2 25.9 | 27.3 81.1 225 10 5 97.8 53.7
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
06/30/2026 AT 1500 MDT | 06/30/2026 AT 1800 MDT
|
CAPE... +26.0 LI... +0.1 | CAPE... +3.2 LI... 0.0
CINH... -9.9 K INDEX... +15.1 | CINH... -1.6 K INDEX... +12.5
|
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 -57.1 -70.8 220 48 25 2.1 1.1 | -56.8 -70.2 225 45 23 2.3 1.3
45000 -54.0 -65.2 220 67 34 2.0 1.1 | -53.8 -64.8 230 62 32 0.7 0.4
40000 -50.8 -59.4 220 79 41 2.8 1.5 | -52.7 -62.9 230 66 34 3.6 2.0
38000 -48.9 -56.0 220 81 42 3.1 1.7 | -49.6 -57.3 230 67 35 5.1 2.8
36000 -47.0 -52.6 215 83 43 3.1 1.7 | -46.5 -51.7 230 69 35 5.1 2.8
34000 -44.3 -47.7 215 82 42 5.5 3.0 | -43.5 -46.3 225 70 36 5.0 2.8
32000 -41.0 -41.8 215 78 40 5.5 3.0 | -40.5 -40.9 220 72 37 5.0 2.8
30000 -37.1 -34.8 215 74 38 7.5 4.1 | -36.8 -34.2 220 71 36 7.1 3.9
29000 -34.8 -30.6 215 73 37 7.5 4.1 | -34.6 -30.3 220 69 36 7.1 3.9
28000 -32.6 -26.7 215 71 37 7.5 4.1 | -32.5 -26.5 220 68 35 7.1 3.9
27000 -30.4 -22.7 215 69 35 7.0 3.8 | -30.4 -22.7 220 65 33 7.1 3.9
26000 -28.3 -18.9 210 66 34 7.0 3.8 | -28.3 -18.9 220 60 31 7.1 3.9
25000 -25.7 -14.3 210 63 32 7.0 3.8 | -25.7 -14.3 220 55 28 7.1 3.9
24000 -23.7 -10.7 210 59 30 6.8 3.7 | -23.6 -10.5 220 50 26 7.0 3.8
23000 -21.7 -7.1 210 54 28 6.8 3.7 | -21.5 -6.7 215 44 23 7.0 3.8
22000 -19.7 -3.5 210 49 25 6.7 3.7 | -19.5 -3.1 215 38 19 6.9 3.8
21000 -17.4 0.7 210 44 23 8.3 4.6 | -17.2 1.0 210 34 18 8.0 4.4
20000 -14.9 5.2 210 39 20 8.3 4.6 | -14.8 5.4 210 32 16 8.0 4.4
19500 -13.7 7.3 210 36 19 8.3 4.6 | -13.7 7.3 210 31 16 8.0 4.4
19000 -12.4 9.7 210 34 17 8.7 4.8 | -12.5 9.5 210 30 15 8.9 4.9
18500 -11.1 12.0 205 32 17 8.8 4.8 | -11.0 12.2 210 29 15 9.4 5.2
18000 -9.8 14.4 205 31 16 8.9 4.9 | -9.6 14.7 210 29 15 9.4 5.2
17500 -8.5 16.7 205 30 15 9.2 5.1 | -8.2 17.2 210 29 15 9.4 5.1
17000 -7.1 19.2 205 29 15 9.2 5.0 | -6.8 19.8 210 28 15 9.4 5.1
16500 -5.7 21.7 205 28 14 9.3 5.1 | -5.4 22.3 210 28 14 9.5 5.2
16000 -4.3 24.3 205 27 14 9.3 5.1 | -4.0 24.8 210 28 14 9.5 5.2
15500 -3.0 26.6 205 27 14 9.3 5.1 | -2.5 27.5 210 28 14 9.5 5.2
15000 -1.6 29.1 205 26 13 9.3 5.1 | -1.1 30.0 210 27 14 9.5 5.2
14500 -0.2 31.6 205 26 13 9.3 5.1 | 0.3 32.5 210 27 14 9.5 5.2
14000 1.2 34.2 205 25 13 9.5 5.2 | 1.7 35.1 215 27 14 9.6 5.3
13500 2.7 36.9 205 25 13 9.5 5.2 | 3.2 37.8 215 26 14 9.6 5.2
13000 4.1 39.4 205 24 13 9.3 5.1 | 4.6 40.3 215 26 13 9.6 5.3
12500 5.5 41.9 205 24 12 9.3 5.1 | 6.0 42.8 215 26 13 9.6 5.3
12000 6.9 44.4 205 23 12 9.4 5.2 | 7.5 45.5 220 25 13 9.3 5.1
11500 8.3 46.9 205 22 11 9.5 5.2 | 8.9 48.0 220 25 13 9.4 5.1
11000 9.6 49.3 205 21 11 8.4 4.6 | 10.2 50.4 220 25 13 8.4 4.6
10500 10.8 51.4 205 21 11 8.6 4.7 | 11.4 52.5 220 23 12 8.5 4.6
10250 11.6 52.9 205 20 10 12.2 6.7 | 12.1 53.8 220 23 12 11.5 6.3
10000 12.5 54.5 205 20 10 11.5 6.3 | 13.0 55.4 225 24 12 10.7 5.9
9750 13.3 55.9 205 20 10 9.0 4.9 | 13.7 56.7 225 23 12 8.4 4.6
9500 14.0 57.2 205 20 10 9.4 5.2 | 14.4 57.9 225 23 12 8.7 4.8
9250 14.7 58.5 205 20 10 10.2 5.6 | 15.0 59.0 225 22 11 9.7 5.3
9000 16.2 61.2 210 20 10 9.9 5.4 | 15.8 60.4 225 23 12 9.9 5.4
8750 17.0 62.6 210 19 10 10.2 5.6 | 17.2 63.0 230 22 11 9.2 5.1
8500 17.7 63.9 210 19 10 9.6 5.2 | 17.8 64.0 230 22 11 9.1 5.0
8250 18.4 65.1 210 19 10 9.7 5.3 | 18.5 65.3 230 21 11 9.3 5.1
8000 19.2 66.6 210 19 10 10.3 5.7 | 19.2 66.6 230 20 10 9.4 5.2
7750 20.0 68.0 210 18 9 10.5 5.8 | 19.9 67.8 235 20 10 9.8 5.4
7500 20.7 69.3 210 18 9 9.3 5.1 | 20.6 69.1 235 20 10 8.4 4.6
7250 21.4 70.5 210 18 9 8.7 4.8 | 21.2 70.2 235 20 10 7.5 4.1
7000 22.1 71.8 210 18 9 10.5 5.8 | 21.8 71.2 235 19 10 9.4 5.2
6750 22.9 73.2 210 17 9 11.2 6.1 | 22.6 72.7 235 19 10 10.2 5.6
6500 23.7 74.7 215 17 9 11.3 6.2 | 23.3 73.9 240 18 9 10.0 5.5
6250 24.6 76.3 210 17 9 12.4 6.8 | 24.1 75.4 235 18 9 10.5 5.8
6000 25.5 77.9 210 17 9 8.3 4.5 | 24.8 76.6 235 17 9 7.7 4.2
5750 26.1 79.0 215 15 8 13.2 7.2 | 25.3 77.5 240 16 8 7.8 4.3
5500 29.3 84.7 210 14 7 95.6 52.4 | 27.0 80.6 235 13 7 47.9 26.3
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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