896
UXUS97 KGJT 251305
SRGGJT
SOARING FORECAST
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO
705 AM MDT MONDAY, MAY 25, 2026
THIS FORECAST IS FOR MONDAY, MAY 25, 2026:
IF THE TRIGGER TEMPERATURE OF 64.3 F/17.9 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1023 FT/MIN (5.2 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 20086 FT MSL (14478 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 85.0 F/29.9 C
TIME OF TRIGGER TEMPERATURE.................... 0645 MDT
TIME OF OVERDEVELOPMENT........................ 1500 MDT
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... BROKEN/OVERCAST THIN MIDDLE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 17422 FT MSL (11813 FT AGL)
THERMAL SOARING OUTLOOK FOR TUESDAY 05/26...... GOOD
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 05:53:17 / 20:28:58 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 35 MIN 40 SEC (875 MIN 40 SEC)
ALTITUDE OF SUN AT 13:11:07 MDT... 71.78 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 05/25/2026 AT 0600 MDT
FREEZING LEVEL.................. 12316 FT MSL (6708 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 11615 FT MSL (6007 FT AGL)
LIFTED CONDENSATION LEVEL....... 15616 FT MSL (10008 FT AGL)
LIFTED INDEX.................... -5.9
K INDEX......................... +23.2
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 -57.9 -72.2 205 17 9 0.2 0.1 M M M M M
45000 -57.9 -72.2 200 18 9 -2.1 -1.2 M M M M M
40000 -61.2 -78.2 190 32 17 -1.9 -1.0 M M M M M
38000 -58.1 -72.6 185 38 20 7.7 4.2 M M M M M
36000 -53.5 -64.3 175 44 23 7.7 4.2 M M M M M
34000 -47.8 -54.0 175 46 24 9.3 5.1 M M M M M
32000 -42.2 -44.0 175 40 21 9.3 5.1 M M M M M
30000 -37.0 -34.6 170 34 17 7.9 4.4 38.0 100.4 6.5 M M
29000 -34.7 -30.5 170 31 16 7.9 4.4 37.3 99.1 6.0 M M
28000 -32.3 -26.1 170 27 14 7.9 4.4 36.7 98.0 5.6 M M
27000 -29.9 -21.8 170 25 13 8.1 4.4 36.0 96.9 5.1 M M
26000 -27.5 -17.5 170 24 12 8.1 4.4 35.3 95.5 4.6 M M
25000 -25.1 -13.2 170 22 11 8.1 4.4 34.7 94.5 4.2 M M
24000 -22.7 -8.9 170 21 11 6.9 3.8 34.1 93.3 3.7 M M
23000 -20.7 -5.3 170 22 11 6.9 3.8 33.0 91.3 2.8 M M
22000 -18.6 -1.5 170 22 11 6.9 3.8 32.0 89.5 2.0 M M
21000 -16.6 2.1 170 22 12 6.3 3.4 30.9 87.7 1.1 M M
20000 -14.3 6.3 175 23 12 6.3 3.5 29.4 84.9 -0.2 1205 6.1
19500 -13.3 8.1 175 23 12 6.3 3.5 28.8 83.8 -0.7 1162 5.9
19000 -12.4 9.7 175 24 12 6.3 3.4 28.3 82.9 -1.2 1119 5.7
18500 -11.5 11.3 175 24 12 6.0 3.3 27.6 81.7 -1.8 1078 5.5
18000 -10.6 12.9 180 24 12 6.0 3.3 27.0 80.6 -2.4 1037 5.3
17500 -9.8 14.4 180 24 12 5.6 3.1 26.3 79.4 -3.0 996 5.1
17000 -9.0 15.8 180 24 12 5.6 3.1 25.6 78.1 -3.7 958 4.9
16500 -8.2 17.2 185 24 12 5.7 3.1 24.9 76.8 -4.4 919 4.7
16000 -7.3 18.9 185 24 12 6.0 3.3 24.2 75.6 -5.0 879 4.5
15500 -6.5 20.3 190 24 12 6.0 3.3 23.6 74.5 -5.7 839 4.3
15000 -5.6 21.9 190 24 12 6.5 3.6 23.0 73.5 -6.3 798 4.1
14500 -4.7 23.5 190 24 12 6.4 3.5 22.5 72.5 -6.9 756 3.8
14000 -3.7 25.3 195 24 12 7.6 4.2 22.0 71.7 -7.4 712 3.6
13500 -2.6 27.3 195 24 12 7.7 4.2 21.7 71.0 -7.8 664 3.4
13000 -1.5 29.3 195 24 12 7.7 4.2 21.4 70.5 -8.2 616 3.1
12500 -0.4 31.3 195 23 12 7.7 4.2 21.0 69.9 -8.6 568 2.9
12000 0.7 33.3 195 22 11 8.0 4.4 20.7 69.3 -9.0 519 2.6
11500 1.9 35.4 195 21 11 8.2 4.5 20.5 68.9 -9.3 469 2.4
11000 3.1 37.6 195 20 10 7.4 4.1 20.2 68.4 -9.6 419 2.1
10500 4.0 39.2 195 20 10 7.3 4.0 19.7 67.5 -10.2 375 1.9
10250 4.6 40.3 195 19 10 8.6 4.7 19.6 67.3 -10.4 351 1.8
10000 5.2 41.4 195 18 9 7.4 4.0 19.5 67.1 -10.5 325 1.7
9750 5.7 42.3 190 18 9 6.2 3.4 19.2 66.6 -10.8 304 1.5
9500 6.1 43.0 190 17 9 6.4 3.5 19.0 66.2 -11.1 283 1.4
9250 6.6 43.9 190 17 9 7.1 3.9 18.7 65.7 -11.4 261 1.3
9000 7.1 44.8 190 16 8 6.5 3.6 18.5 65.4 -11.6 238 1.2
8750 7.5 45.5 185 15 8 5.6 3.0 18.2 64.8 -12.0 218 1.1
8500 8.0 46.4 185 14 7 5.7 3.1 17.9 64.2 -12.3 199 1.0
8250 8.4 47.1 185 14 7 6.2 3.4 17.6 63.7 -12.7 179 0.9
8000 8.8 47.8 180 13 7 6.0 3.3 17.3 63.2 -13.0 158 0.8
7750 9.2 48.6 180 12 6 5.3 2.9 17.0 62.6 -13.4 139 0.7
7500 9.6 49.3 175 11 6 5.5 3.0 16.7 62.0 -13.7 120 0.6
7250 10.0 50.0 175 10 5 5.2 2.8 16.4 61.4 -14.1 101 0.5
7000 10.4 50.7 170 9 4 5.1 2.8 16.0 60.8 -14.5 83 0.4
6750 10.7 51.3 165 8 4 5.5 3.0 15.7 60.2 -14.9 64 0.3
6500 11.1 52.0 165 7 3 5.2 2.8 15.3 59.6 -15.3 45 0.2
6250 11.5 52.7 155 6 3 5.8 3.2 15.0 59.0 -15.6 26 0.1
6000 11.9 53.4 140 5 2 1.8 1.0 14.6 58.3 -16.0 8 0.0
5750 11.6 52.9 125 4 2 -6.6 -3.6 13.7 56.6 -17.0 7 0.0
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 * * * * * *
05/25/2026 AT 0900 MDT | 05/25/2026 AT 1200 MDT
|
CAPE... +4.9 LI... +0.2 | CAPE... +122.4 LI... -0.7
CINH... -26.2 K INDEX... +20.0 | CINH... -14.6 K INDEX... +20.8
|
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 -59.7 -75.5 235 13 7 0.0 0.0 | -59.7 -75.5 230 14 7 0.5 0.3
45000 -59.7 -75.5 220 13 7 -0.4 -0.2 | -59.2 -74.6 215 17 9 -1.4 -0.7
40000 -60.3 -76.5 200 26 13 -0.3 -0.2 | -61.4 -78.5 195 24 12 -1.4 -0.8
38000 -57.8 -72.0 210 30 15 5.4 3.0 | -58.2 -72.8 200 27 14 6.3 3.5
36000 -54.1 -65.4 220 36 18 5.4 3.0 | -54.4 -65.9 205 30 15 6.3 3.5
34000 -49.7 -57.5 225 35 18 9.0 5.0 | -49.7 -57.5 205 29 15 9.0 5.0
32000 -44.2 -47.6 225 28 14 9.0 5.0 | -44.2 -47.6 205 26 13 9.0 5.0
30000 -39.2 -38.6 220 22 11 7.7 4.3 | -39.0 -38.2 205 24 13 8.5 4.7
29000 -36.9 -34.4 215 20 10 7.7 4.3 | -36.4 -33.5 200 25 13 8.5 4.7
28000 -34.6 -30.3 210 17 9 7.8 4.3 | -33.9 -29.0 200 25 13 8.6 4.7
27000 -32.4 -26.3 205 16 8 7.3 4.0 | -31.5 -24.7 195 25 13 7.6 4.2
26000 -30.2 -22.4 205 16 8 7.3 4.0 | -29.2 -20.6 195 23 12 7.6 4.2
25000 -28.0 -18.4 210 15 8 7.4 4.0 | -27.0 -16.6 190 22 11 7.6 4.2
24000 -25.8 -14.4 210 15 8 7.7 4.2 | -24.8 -12.6 185 20 10 6.7 3.7
23000 -23.0 -9.4 205 15 8 7.7 4.2 | -22.3 -8.1 185 16 8 6.8 3.7
22000 -20.7 -5.3 205 16 8 7.6 4.2 | -20.3 -4.5 180 13 7 6.6 3.6
21000 -18.3 -0.9 205 16 8 8.4 4.6 | -18.0 -0.4 175 12 6 8.2 4.5
20000 -15.8 3.6 210 16 8 8.4 4.6 | -15.6 3.9 175 11 6 8.2 4.5
19500 -14.6 5.7 210 16 8 8.4 4.6 | -14.4 6.1 170 11 5 8.3 4.5
19000 -13.4 7.9 210 16 8 8.3 4.6 | -13.2 8.2 170 10 5 8.0 4.4
18500 -12.1 10.2 205 15 8 8.3 4.6 | -12.0 10.4 170 10 5 7.9 4.3
18000 -10.9 12.4 205 14 7 8.4 4.6 | -10.9 12.4 165 10 5 7.9 4.3
17500 -9.7 14.5 200 13 7 8.5 4.7 | -9.7 14.5 165 10 5 8.4 4.6
17000 -8.4 16.9 195 12 6 8.5 4.6 | -8.4 16.9 165 10 5 8.3 4.6
16500 -7.1 19.2 190 11 6 9.0 4.9 | -7.2 19.0 165 10 5 8.8 4.8
16000 -5.8 21.6 190 10 5 9.0 4.9 | -5.9 21.4 160 10 5 8.9 4.9
15500 -4.4 24.1 185 9 5 9.1 5.0 | -4.5 23.9 160 10 5 9.0 4.9
15000 -3.1 26.4 180 9 4 9.2 5.1 | -3.2 26.2 160 10 5 9.2 5.0
14500 -1.7 28.9 180 8 4 9.2 5.1 | -1.8 28.8 160 10 5 9.2 5.1
14000 -0.3 31.5 180 7 4 9.3 5.1 | -0.4 31.3 160 10 5 9.5 5.2
13500 1.1 34.0 180 7 4 9.4 5.1 | 1.0 33.8 165 10 5 9.5 5.2
13000 2.5 36.5 180 7 3 9.1 5.0 | 2.4 36.3 165 10 5 9.4 5.2
12500 3.8 38.8 175 6 3 9.2 5.0 | 3.8 38.8 165 10 5 9.4 5.2
12000 5.2 41.4 170 6 3 9.1 5.0 | 5.2 41.4 170 10 5 9.3 5.1
11500 6.5 43.7 165 7 3 9.2 5.1 | 6.6 43.9 170 10 5 9.4 5.1
11000 7.8 46.0 160 7 4 7.7 4.2 | 7.9 46.2 175 10 5 7.8 4.3
10500 8.9 48.0 150 8 4 7.1 3.9 | 9.0 48.2 175 10 5 7.5 4.1
10250 9.5 49.1 150 8 4 9.7 5.3 | 9.7 49.5 175 10 5 11.6 6.4
10000 10.3 50.5 145 8 4 10.1 5.5 | 10.6 51.1 175 10 5 11.8 6.5
9750 10.9 51.6 145 8 4 7.7 4.2 | 11.3 52.3 175 10 5 8.4 4.6
9500 11.5 52.7 140 9 4 8.5 4.7 | 12.0 53.6 175 10 5 9.7 5.3
9250 12.1 53.8 140 9 5 7.5 4.1 | 12.7 54.9 180 10 5 7.8 4.3
9000 12.6 54.7 140 10 5 6.8 3.8 | 13.2 55.8 175 9 5 8.1 4.4
8750 13.2 55.8 135 10 5 7.1 3.9 | 13.9 57.0 175 9 5 9.7 5.3
8500 13.7 56.7 135 10 5 7.5 4.1 | 15.3 59.5 180 9 5 8.7 4.8
8250 14.5 58.1 135 10 5 4.3 2.4 | 15.9 60.6 175 8 4 8.7 4.8
8000 14.9 58.8 135 10 5 5.9 3.3 | 16.6 61.9 175 8 4 10.0 5.5
7750 15.3 59.5 130 9 5 5.5 3.0 | 17.3 63.1 175 8 4 9.8 5.4
7500 15.6 60.1 130 9 5 3.0 1.6 | 18.0 64.4 175 8 4 8.6 4.7
7250 15.8 60.4 135 9 5 1.8 1.0 | 18.6 65.5 175 7 4 8.4 4.6
7000 16.0 60.8 135 9 5 5.3 2.9 | 19.4 66.9 170 7 4 10.9 6.0
6750 16.4 61.5 125 8 4 5.8 3.2 | 20.2 68.4 175 7 4 11.6 6.4
6500 16.8 62.2 125 7 4 4.1 2.3 | 21.0 69.8 175 7 4 10.8 5.9
6250 17.0 62.6 125 7 4 3.5 1.9 | 21.9 71.4 170 7 3 11.1 6.1
6000 17.4 63.3 130 7 3 7.4 4.1 | 22.6 72.7 170 6 3 8.8 4.8
5750 18.3 64.9 120 6 3 17.7 9.7 | 23.3 73.9 175 7 3 14.3 7.8
5500 19.6 67.3 120 5 3 12.1 6.7 | 26.0 78.8 170 5 3 72.7 39.9
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
05/25/2026 AT 1500 MDT | 05/25/2026 AT 1800 MDT
|
CAPE... +140.7 LI... -0.7 | CAPE... +138.4 LI... -0.4
CINH... -23.7 K INDEX... +24.1 | CINH... -23.4 K INDEX... +25.9
|
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 -75.3 230 16 8 0.2 0.1 | -59.2 -74.6 230 18 9 0.1 0.1
45000 -59.4 -74.9 215 17 9 -1.1 -0.6 | -59.3 -74.7 215 18 9 -1.6 -0.9
40000 -61.0 -77.8 185 25 13 -1.2 -0.6 | -61.8 -79.2 190 28 14 -1.7 -1.0
38000 -57.8 -72.0 190 28 14 6.2 3.4 | -58.0 -72.4 190 32 16 7.3 4.0
36000 -54.2 -65.6 190 31 16 6.1 3.4 | -53.7 -64.7 190 35 18 7.3 4.0
34000 -49.4 -56.9 190 30 15 9.3 5.1 | -48.7 -55.7 185 33 17 9.1 5.0
32000 -43.8 -46.8 190 26 13 9.3 5.1 | -43.2 -45.8 180 29 15 9.1 5.0
30000 -38.4 -37.1 185 23 12 8.9 4.9 | -37.8 -36.0 175 26 14 8.8 4.8
29000 -35.7 -32.3 180 23 12 8.9 4.9 | -35.2 -31.4 175 26 14 8.8 4.8
28000 -33.1 -27.6 175 23 12 8.9 4.9 | -32.5 -26.5 170 26 14 8.8 4.8
27000 -30.6 -23.1 170 23 12 7.9 4.3 | -30.0 -22.0 170 26 13 8.0 4.4
26000 -28.3 -18.9 170 23 12 7.9 4.3 | -27.6 -17.7 170 24 12 8.0 4.4
25000 -25.9 -14.6 165 23 12 7.9 4.3 | -25.3 -13.5 170 23 12 8.0 4.4
24000 -23.1 -9.6 165 23 12 7.5 4.1 | -22.4 -8.3 170 22 11 7.3 4.0
23000 -20.9 -5.6 170 22 11 7.5 4.1 | -20.2 -4.4 170 23 12 7.3 4.0
22000 -18.7 -1.7 170 20 11 7.5 4.1 | -18.1 -0.6 170 24 12 7.3 4.0
21000 -16.5 2.3 170 20 10 7.2 3.9 | -15.9 3.4 170 25 13 7.4 4.1
20000 -14.4 6.1 165 20 10 7.2 3.9 | -13.7 7.3 170 26 13 7.4 4.1
19500 -13.4 7.9 165 20 10 7.2 4.0 | -12.7 9.1 170 26 13 7.4 4.1
19000 -12.3 9.9 165 20 10 7.5 4.1 | -11.6 11.1 175 27 14 7.2 4.0
18500 -11.2 11.8 160 20 10 7.6 4.2 | -10.6 12.9 175 25 13 7.0 3.8
18000 -10.1 13.8 160 20 10 7.6 4.2 | -9.5 14.9 175 24 12 7.0 3.8
17500 -9.0 15.8 160 20 10 7.8 4.3 | -8.5 16.7 175 22 11 7.6 4.1
17000 -7.8 18.0 160 19 10 7.8 4.3 | -7.4 18.7 175 20 10 7.5 4.1
16500 -6.6 20.1 160 18 9 8.0 4.4 | -6.3 20.7 175 18 9 7.4 4.1
16000 -5.5 22.1 160 18 9 8.1 4.4 | -5.2 22.6 180 17 9 7.4 4.1
15500 -4.3 24.3 160 17 9 8.2 4.5 | -4.1 24.6 180 15 8 7.6 4.2
15000 -3.0 26.6 165 16 8 8.3 4.6 | -3.0 26.6 185 15 8 8.3 4.6
14500 -1.8 28.8 165 16 8 8.3 4.6 | -1.7 28.9 185 14 7 8.2 4.5
14000 -0.5 31.1 165 16 8 8.7 4.8 | -0.5 31.1 185 13 7 9.0 4.9
13500 0.7 33.3 170 15 8 8.6 4.7 | 0.8 33.4 185 13 7 8.9 4.9
13000 2.0 35.6 170 15 8 9.0 5.0 | 2.2 36.0 185 13 7 9.2 5.0
12500 3.4 38.1 175 14 7 9.0 4.9 | 3.5 38.3 185 13 7 9.2 5.0
12000 4.7 40.5 180 14 7 9.1 5.0 | 4.9 40.8 185 13 7 9.3 5.1
11500 6.0 42.8 180 13 7 9.2 5.0 | 6.3 43.3 185 13 7 9.4 5.2
11000 7.3 45.1 185 13 7 8.0 4.4 | 7.7 45.9 180 12 6 8.0 4.4
10500 8.5 47.3 185 12 6 7.4 4.0 | 8.8 47.8 180 12 6 7.1 3.9
10250 9.2 48.6 190 12 6 11.9 6.5 | 9.4 48.9 175 12 6 11.3 6.2
10000 10.2 50.4 190 12 6 12.4 6.8 | 10.4 50.7 180 11 6 11.5 6.3
9750 10.9 51.6 195 12 6 8.5 4.7 | 11.0 51.8 175 11 6 7.7 4.2
9500 11.6 52.9 195 12 6 10.0 5.5 | 11.6 52.9 175 10 5 9.2 5.0
9250 12.3 54.1 195 12 6 8.0 4.4 | 12.3 54.1 175 10 5 7.1 3.9
9000 12.8 55.0 200 11 6 8.3 4.5 | 12.8 55.0 170 9 5 7.5 4.1
8750 14.3 57.7 205 11 5 9.8 5.4 | 13.4 56.1 165 9 4 9.3 5.1
8500 15.0 59.0 205 11 5 8.9 4.9 | 14.7 58.5 165 8 4 7.9 4.4
8250 15.6 60.1 210 10 5 8.7 4.8 | 15.3 59.5 155 7 4 8.1 4.4
8000 16.3 61.3 210 9 5 9.8 5.4 | 16.0 60.8 155 7 4 9.8 5.4
7750 17.0 62.6 215 9 5 9.9 5.5 | 16.7 62.1 160 7 3 10.3 5.7
7500 17.7 63.9 215 9 5 8.2 4.5 | 17.4 63.3 160 7 3 8.4 4.6
7250 18.3 64.9 220 9 4 7.4 4.1 | 18.0 64.4 155 6 3 7.1 3.9
7000 18.9 66.0 220 8 4 10.4 5.7 | 18.6 65.5 155 6 3 10.4 5.7
6750 19.7 67.5 220 8 4 11.4 6.3 | 19.5 67.1 155 6 3 11.7 6.4
6500 20.5 68.9 225 8 4 10.5 5.8 | 20.3 68.5 160 6 3 10.1 5.6
6250 21.3 70.3 225 8 4 11.1 6.1 | 21.0 69.8 155 5 3 9.7 5.3
6000 22.1 71.8 225 7 4 7.7 4.2 | 21.7 71.1 155 5 3 8.8 4.8
5750 22.6 72.7 225 8 4 11.6 6.4 | 22.4 72.3 155 5 3 11.3 6.2
5500 25.5 77.9 230 6 3 84.1 46.1 | 24.1 75.4 150 4 2 44.2 24.3
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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