816  
UXUS97 KGJT 231218  
SRGGJT  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO  
0618 MDT FRIDAY, JUNE 23, 2017  
 
THIS FORECAST IS FOR FRIDAY, JUNE 23, 2017:  
 
IF THE TRIGGER TEMPERATURE OF 80.6 F/27.0 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... EXCELLENT  
MAXIMUM RATE OF LIFT........................ 884 FT/MIN (4.5 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 15624 FT MSL (10785 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 93.0 F/34.3 C  
TIME OF TRIGGER TEMPERATURE.................... 1045 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................. 13125 FT MSL (8286 FT AGL)  
THERMAL SOARING OUTLOOK FOR SATURDAY 06/24..... EXCELLENT  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
SUNRISE/SUNSET.................... 05:49:05 / 20:43:44 MDT  
TOTAL POSSIBLE SUNSHINE........... 14 HR 54 MIN 39 SEC (894 MIN 39 SEC)  
ALTITUDE OF SUN AT 13:16:31 MDT... 74.26 DEGREES  
 
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 06/23/2017 AT 0600 MDT  
 
FREEZING LEVEL.................. 16161 FT MSL (11322 FT AGL)  
CONVECTIVE CONDENSATION LEVEL... 21704 FT MSL (16865 FT AGL)  
LIFTED CONDENSATION LEVEL....... 19956 FT MSL (15116 FT AGL)  
LIFTED INDEX.................... +2.0  
K INDEX......................... -6.5  
 
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 -62.5 -80.5 300 30 15 6.7 3.7 91.3 196.4 33.2 M M  
45000 -59.9 -75.8 290 60 31 8.2 4.5 69.9 157.8 22.4 M M  
40000 -54.3 -65.7 285 59 30 2.0 1.1 56.0 132.8 14.7 M M  
38000 -51.5 -60.7 290 59 31 7.5 4.1 51.2 124.2 11.9 M M  
36000 -47.0 -52.6 295 60 31 7.5 4.1 49.4 120.8 10.8 M M  
34000 -42.3 -44.1 295 58 30 7.0 3.8 47.8 118.1 10.0 M M  
32000 -37.1 -34.8 295 56 29 9.0 4.9 46.0 114.9 9.0 M M  
30000 -32.0 -25.6 290 50 26 8.5 4.7 45.1 113.2 8.5 M M  
29000 -29.4 -20.9 295 50 26 8.4 4.6 44.6 112.2 8.2 M M  
28000 -27.5 -17.5 295 50 26 4.5 2.5 43.3 110.0 7.3 M M  
27000 -25.3 -13.5 295 41 21 9.1 5.0 42.3 108.2 6.6 M M  
26000 -22.5 -8.5 295 33 17 9.4 5.2 42.1 107.9 6.5 M M  
25000 -20.4 -4.7 295 24 12 5.9 3.2 41.1 106.0 5.8 M M  
24000 -18.2 -0.8 285 29 15 7.7 4.2 40.3 104.5 5.2 M M  
23000 -15.6 3.9 290 29 15 9.2 5.1 39.8 103.7 4.9 M M  
22000 -12.8 9.0 300 29 15 8.5 4.6 39.7 103.4 4.8 M M  
21000 -10.4 13.3 305 29 15 7.9 4.3 39.0 102.3 4.3 M M  
20000 -8.1 17.4 300 29 15 7.9 4.3 38.4 101.1 3.8 M M  
19500 -6.9 19.6 295 31 16 7.0 3.8 38.1 100.5 3.5 M M  
19000 -6.0 21.2 295 31 16 7.0 3.9 37.5 99.4 3.0 M M  
18500 -4.9 23.2 295 29 15 7.3 4.0 37.0 98.6 2.7 M M  
18000 -3.8 25.2 300 27 14 7.3 4.0 36.6 97.8 2.3 M M  
17500 -2.1 28.2 305 24 13 7.2 4.0 36.0 96.7 1.8 M M  
17000 -1.0 30.2 305 23 12 5.9 3.3 35.6 96.1 1.5 M M  
16500 -0.5 31.1 300 25 13 5.1 2.8 34.5 94.2 0.5 M M  
16000 0.6 33.1 300 28 14 8.0 4.4 34.2 93.5 0.2 M M  
15500 1.8 35.2 295 32 17 8.3 4.6 33.9 93.0 -0.1 862 4.4  
15000 2.8 37.0 295 35 18 5.5 3.0 33.4 92.2 -0.5 817 4.1  
14500 3.7 38.7 295 29 15 5.8 3.2 32.8 91.0 -1.2 776 3.9  
14000 4.6 40.3 300 22 12 5.9 3.2 32.1 89.8 -1.7 735 3.7  
13500 5.4 41.7 305 18 9 4.9 2.7 31.4 88.6 -2.4 697 3.5  
13000 6.0 42.8 315 14 7 5.4 3.0 30.6 87.1 -3.3 664 3.4  
12500 6.3 43.3 320 8 4 -1.5 -0.8 29.5 85.2 -4.5 639 3.2  
12000 6.4 43.5 340 2 1 7.8 4.3 28.2 82.7 -5.9 621 3.2  
11500 7.8 46.0 015 3 2 9.2 5.1 28.1 82.6 -6.0 565 2.9  
11000 9.2 48.6 025 5 2 9.3 5.1 28.0 82.4 -6.1 508 2.6  
10500 10.6 51.1 035 6 3 9.3 5.1 28.0 82.4 -6.1 451 2.3  
10250 11.3 52.3 030 8 4 9.1 5.0 27.9 82.3 -6.2 423 2.2  
10000 11.9 53.4 025 10 5 9.0 5.0 27.9 82.2 -6.3 396 2.0  
9750 12.6 54.7 025 10 5 9.1 5.0 27.8 82.1 -6.3 368 1.9  
9500 13.3 55.9 020 11 6 9.1 5.0 27.8 82.0 -6.4 340 1.7  
9250 14.0 57.2 020 11 6 9.1 5.0 27.7 81.9 -6.5 313 1.6  
9000 14.6 58.3 020 12 6 9.1 5.0 27.7 81.8 -6.5 285 1.4  
8750 15.3 59.5 030 13 7 8.1 4.4 27.6 81.7 -6.6 258 1.3  
8500 15.9 60.6 035 14 7 7.3 4.0 27.4 81.4 -6.8 234 1.2  
8250 16.4 61.5 040 16 8 7.6 4.2 27.2 81.0 -7.0 210 1.1  
8000 17.0 62.6 045 18 9 7.3 4.0 27.1 80.7 -7.2 186 0.9  
7750 17.5 63.5 045 17 9 8.1 4.4 26.9 80.4 -7.4 162 0.8  
7500 18.1 64.6 050 15 8 5.3 2.9 26.7 80.1 -7.6 138 0.7  
7250 18.3 64.9 050 14 7 1.5 0.8 26.2 79.2 -8.1 124 0.6  
7000 18.5 65.3 055 12 6 6.7 3.7 25.7 78.3 -8.6 109 0.6  
6750 19.3 66.7 055 11 6 10.6 5.8 25.7 78.3 -8.7 80 0.4  
6500 20.0 68.0 055 10 5 9.6 5.3 25.7 78.3 -8.7 51 0.3  
6250 20.7 69.3 055 9 5 9.8 5.4 25.7 78.3 -8.7 22 0.1  
6000 21.4 70.5 055 8 4 9.9 5.5 25.7 78.3 -8.7 M M  
5750 22.1 71.8 055 7 3 9.2 5.1 25.7 78.3 -8.8 M M  
5500 22.7 72.9 050 5 3 4.6 2.5 25.5 78.0 -9.0 M M  
5250 22.9 73.2 045 3 2 3.3 1.8 25.0 77.0 -9.5 M M  
5000 23.1 73.6 035 2 1 0.1 0.0 24.5 76.1 -10.1 M M  
 
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *  
 
06/23/2017 AT 0900 MDT | 06/23/2017 AT 1200 MDT  
|  
K INDEX... -0.2 LI... +4.2 | K INDEX... -6.3 LI... +2.7  
CAPE... 0.0 CIN... 0.0 | CAPE... 0.0 CIN... 0.0  
|  
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 -62.6 -80.7 305 42 22 1.4 0.7 | -62.9 -81.2 305 41 21 1.4 0.8  
45000 -59.5 -75.1 305 57 29 3.5 1.9 | -59.6 -75.3 300 53 27 3.9 2.1  
40000 -53.9 -65.0 305 59 31 6.7 3.7 | -53.4 -64.1 295 60 31 6.2 3.4  
38000 -49.9 -57.8 305 60 31 6.6 3.6 | -49.7 -57.5 300 57 29 6.2 3.4  
36000 -46.0 -50.8 305 61 32 6.6 3.6 | -46.0 -50.8 300 54 28 6.1 3.3  
34000 -41.2 -42.2 305 60 31 8.2 4.5 | -41.2 -42.2 305 54 28 8.4 4.6  
32000 -35.7 -32.3 305 58 30 8.3 4.5 | -35.5 -31.9 305 54 28 8.4 4.6  
30000 -31.4 -24.5 305 53 27 7.1 3.9 | -30.8 -23.4 305 50 26 7.8 4.3  
29000 -29.2 -20.6 305 49 25 7.1 3.9 | -28.4 -19.1 305 48 25 7.8 4.3  
28000 -27.1 -16.8 300 46 24 6.9 3.8 | -26.1 -15.0 305 46 24 6.7 3.7  
27000 -25.0 -13.0 300 43 22 6.9 3.8 | -24.3 -11.7 305 43 22 6.3 3.4  
26000 -23.0 -9.4 300 40 21 6.9 3.8 | -22.4 -8.3 305 40 21 6.3 3.4  
25000 -21.0 -5.8 300 37 19 6.9 3.8 | -20.5 -4.9 305 37 19 6.3 3.5  
24000 -18.7 -1.7 300 35 18 7.6 4.2 | -18.4 -1.1 305 35 18 7.1 3.9  
23000 -16.4 2.5 300 33 17 7.6 4.2 | -16.3 2.7 305 34 17 7.1 3.9  
22000 -14.2 6.4 300 31 16 7.7 4.2 | -14.2 6.4 300 32 17 7.3 4.0  
21000 -11.7 10.9 300 31 16 8.1 4.4 | -11.9 10.6 300 30 16 7.8 4.3  
20000 -9.3 15.3 300 30 15 8.1 4.4 | -9.6 14.7 300 28 14 7.8 4.3  
19500 -8.1 17.4 300 30 15 8.1 4.4 | -8.4 16.9 300 27 14 7.8 4.3  
19000 -6.9 19.6 300 29 15 7.8 4.3 | -7.2 19.0 300 26 13 7.8 4.3  
18500 -5.7 21.7 300 29 15 7.8 4.3 | -6.0 21.2 305 25 13 7.8 4.3  
18000 -4.6 23.7 300 28 14 7.7 4.2 | -4.8 23.4 305 23 12 7.8 4.3  
17500 -3.4 25.9 305 27 14 7.6 4.2 | -3.7 25.3 305 21 11 7.7 4.2  
17000 -2.3 27.9 305 26 14 7.7 4.2 | -2.5 27.5 305 20 10 7.7 4.2  
16500 -1.2 29.8 305 25 13 6.8 3.7 | -1.4 29.5 310 18 9 7.3 4.0  
16000 -0.2 31.6 305 24 12 6.8 3.7 | -0.3 31.5 310 17 9 7.3 4.0  
15500 0.8 33.4 310 23 12 6.8 3.7 | 0.8 33.4 315 15 8 7.2 4.0  
15000 2.3 36.1 310 21 11 6.8 3.7 | 2.4 36.3 315 14 7 7.1 3.9  
14500 3.3 37.9 310 19 10 6.2 3.4 | 3.5 38.3 315 13 7 7.2 3.9  
14000 4.2 39.6 315 18 9 6.0 3.3 | 4.5 40.1 320 13 7 7.2 3.9  
13500 5.1 41.2 315 16 8 5.8 3.2 | 5.6 42.1 320 12 6 6.4 3.5  
13000 5.9 42.6 320 14 7 5.7 3.1 | 6.5 43.7 320 11 6 5.8 3.2  
12500 6.7 44.1 320 12 6 5.5 3.0 | 7.3 45.1 325 10 5 5.4 3.0  
12000 7.3 45.1 320 9 5 5.2 2.9 | 8.0 46.4 330 7 4 5.1 2.8  
11500 8.0 46.4 325 6 3 6.1 3.3 | 8.6 47.5 335 5 3 5.9 3.2  
11000 9.0 48.2 330 5 3 7.6 4.2 | 9.5 49.1 335 4 2 6.7 3.7  
10500 10.1 50.2 345 4 2 4.0 2.2 | 10.5 50.9 335 4 2 4.0 2.2  
10250 10.3 50.5 360 4 2 5.6 3.0 | 10.7 51.3 335 4 2 5.9 3.2  
10000 11.0 51.8 015 5 3 11.3 6.2 | 11.4 52.5 340 4 2 10.9 6.0  
9750 11.8 53.2 025 6 3 10.4 5.7 | 12.1 53.8 340 4 2 10.2 5.6  
9500 12.5 54.5 035 7 4 8.2 4.5 | 12.8 55.0 340 5 2 8.2 4.5  
9250 13.0 55.4 035 8 4 5.8 3.2 | 13.3 55.9 340 5 2 7.1 3.9  
9000 13.5 56.3 035 9 5 8.1 4.4 | 13.9 57.0 340 5 2 9.8 5.4  
8750 14.2 57.6 040 10 5 9.6 5.2 | 14.6 58.3 340 5 2 10.3 5.7  
8500 14.8 58.6 040 11 6 7.3 4.0 | 15.4 59.7 340 5 2 9.6 5.3  
8250 15.2 59.4 040 11 6 5.5 3.0 | 16.0 60.8 340 5 2 8.9 4.9  
8000 15.7 60.3 040 11 6 5.1 2.8 | 16.7 62.1 340 5 2 9.5 5.2  
7750 16.0 60.8 040 11 6 4.0 2.2 | 17.4 63.3 335 5 2 9.9 5.4  
7500 16.2 61.2 040 11 6 1.6 0.9 | 18.1 64.6 335 5 2 9.9 5.4  
7250 16.2 61.2 040 10 5 0.1 0.0 | 18.9 66.0 335 5 2 10.0 5.5  
7000 16.2 61.2 040 10 5 -0.6 -0.3 | 19.6 67.3 335 5 2 10.0 5.5  
6750 16.1 61.0 040 9 5 1.4 0.8 | 20.4 68.7 330 5 2 10.7 5.9  
6500 16.4 61.5 035 8 4 6.2 3.4 | 21.2 70.2 330 5 2 11.3 6.2  
6250 16.9 62.4 035 7 4 6.8 3.8 | 22.1 71.8 330 4 2 12.0 6.6  
6000 17.4 63.3 030 6 3 7.0 3.9 | 22.9 73.2 325 4 2 10.0 5.5  
5750 18.1 64.6 025 6 3 10.5 5.7 | 23.7 74.7 325 4 2 13.3 7.3  
5500 19.0 66.2 025 6 3 13.0 7.1 | 25.0 77.0 325 5 2 18.7 10.3  
5250 19.9 67.8 025 6 3 11.1 6.1 | 26.2 79.2 330 5 2 14.4 7.9  
5000 M M M M M M M | M M M M M M M  
 
06/23/2017 AT 1500 MDT | 06/23/2017 AT 1800 MDT  
|  
K INDEX... -14.4 LI... +2.5 | K INDEX... -3.1 LI... +2.1  
CAPE... 0.0 CIN... 0.0 | CAPE... 0.0 CIN... 0.0  
|  
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 -62.5 -80.5 310 43 22 1.0 0.5 | -62.5 -80.5 310 42 22 1.2 0.7  
45000 -59.8 -75.6 300 56 29 3.8 2.1 | -59.5 -75.1 305 55 28 4.0 2.2  
40000 -53.7 -64.7 295 62 32 6.3 3.4 | -52.8 -63.0 300 56 29 5.9 3.3  
38000 -49.9 -57.8 295 57 29 6.3 3.5 | -49.2 -56.6 300 54 28 6.0 3.3  
36000 -46.1 -51.0 300 53 27 6.2 3.4 | -45.7 -50.3 300 52 27 5.8 3.2  
34000 -41.4 -42.5 300 52 27 8.2 4.5 | -41.1 -42.0 300 50 26 7.9 4.3  
32000 -35.8 -32.4 300 51 26 8.2 4.5 | -36.3 -33.3 300 49 25 7.8 4.3  
30000 -30.9 -23.6 300 48 25 8.2 4.5 | -31.3 -24.3 305 46 24 8.5 4.7  
29000 -28.4 -19.1 305 46 24 8.2 4.5 | -28.8 -19.8 305 44 23 8.5 4.7  
28000 -26.0 -14.8 305 44 23 6.9 3.8 | -26.2 -15.2 305 42 22 8.0 4.4  
27000 -24.0 -11.2 305 41 21 6.5 3.6 | -24.0 -11.2 305 40 21 7.4 4.0  
26000 -22.1 -7.8 305 38 19 6.5 3.6 | -21.3 -6.3 305 37 19 7.4 4.0  
25000 -20.2 -4.4 300 35 18 6.5 3.6 | -19.1 -2.4 305 35 18 6.9 3.8  
24000 -18.2 -0.8 300 33 17 6.7 3.7 | -17.2 1.0 300 34 17 6.2 3.4  
23000 -16.1 3.0 300 31 16 6.7 3.7 | -15.3 4.5 300 32 17 6.2 3.4  
22000 -14.1 6.6 300 29 15 7.0 3.8 | -13.5 7.7 300 31 16 6.7 3.7  
21000 -11.9 10.6 300 27 14 7.5 4.1 | -11.3 11.7 300 29 15 7.3 4.0  
20000 -9.7 14.5 300 25 13 7.5 4.1 | -9.1 15.6 305 27 14 7.3 4.0  
19500 -8.5 16.7 300 24 12 7.5 4.1 | -8.1 17.4 305 26 13 7.3 4.0  
19000 -7.4 18.7 300 22 12 7.9 4.3 | -7.0 19.4 305 25 13 7.3 4.0  
18500 -6.2 20.8 300 21 11 7.9 4.3 | -5.9 21.4 305 24 12 7.3 4.0  
18000 -5.0 23.0 300 20 10 7.8 4.3 | -4.8 23.4 305 23 12 7.5 4.1  
17500 -3.8 25.2 305 19 10 7.7 4.2 | -3.7 25.3 305 22 11 7.6 4.2  
17000 -2.7 27.1 305 17 9 7.7 4.2 | -2.5 27.5 310 21 11 7.6 4.2  
16500 -1.5 29.3 305 16 8 7.8 4.3 | -1.3 29.7 310 20 10 7.9 4.4  
16000 -0.3 31.5 305 15 8 7.8 4.3 | -0.2 31.6 310 19 10 7.9 4.3  
15500 1.4 34.5 310 13 7 8.2 4.5 | 1.0 33.8 310 18 9 8.0 4.4  
15000 2.7 36.9 310 12 6 8.2 4.5 | 2.2 36.0 315 16 8 8.0 4.4  
14500 3.9 39.0 310 11 6 7.7 4.2 | 3.4 38.1 320 14 7 8.1 4.4  
14000 5.0 41.0 310 11 5 7.7 4.2 | 4.5 40.1 320 13 7 8.0 4.4  
13500 6.2 43.2 310 10 5 7.4 4.1 | 5.7 42.3 325 12 6 8.1 4.5  
13000 7.2 45.0 315 9 4 7.3 4.0 | 7.5 45.5 335 11 6 8.6 4.7  
12500 8.3 46.9 320 8 4 7.3 4.0 | 8.8 47.8 340 10 5 8.3 4.6  
12000 9.3 48.7 325 7 4 7.4 4.0 | 9.9 49.8 340 10 5 8.2 4.5  
11500 10.4 50.7 330 7 4 7.4 4.1 | 11.1 52.0 345 9 5 8.4 4.6  
11000 11.4 52.5 330 7 3 7.2 3.9 | 12.3 54.1 345 8 4 8.4 4.6  
10500 12.4 54.3 335 7 3 4.4 2.4 | 13.5 56.3 345 8 4 5.4 3.0  
10250 12.6 54.7 330 7 3 5.7 3.1 | 13.8 56.8 345 8 4 6.4 3.5  
10000 13.3 55.9 330 7 3 10.4 5.7 | 14.5 58.1 340 7 4 11.1 6.1  
9750 14.0 57.2 330 6 3 9.5 5.2 | 15.3 59.5 340 7 4 10.5 5.8  
9500 14.6 58.3 330 6 3 8.7 4.8 | 16.0 60.8 340 7 4 8.2 4.5  
9250 15.2 59.4 330 6 3 8.4 4.6 | 16.5 61.7 335 7 3 7.4 4.1  
9000 15.8 60.4 325 6 3 10.0 5.5 | 17.2 63.0 335 6 3 10.0 5.5  
8750 16.5 61.7 325 6 3 10.0 5.5 | 17.9 64.2 330 6 3 9.4 5.2  
8500 17.2 63.0 325 6 3 10.1 5.6 | 18.6 65.5 330 6 3 9.9 5.5  
8250 18.0 64.4 325 6 3 10.2 5.6 | 19.3 66.7 325 6 3 10.2 5.6  
8000 18.7 65.7 320 6 3 9.5 5.2 | 20.1 68.2 325 6 3 9.7 5.3  
7750 19.4 66.9 320 6 3 9.2 5.0 | 20.8 69.4 320 6 3 9.5 5.2  
7500 20.2 68.4 320 6 3 10.3 5.6 | 21.5 70.7 320 6 3 9.9 5.4  
7250 21.0 69.8 315 6 3 11.3 6.2 | 22.2 72.0 320 6 3 10.3 5.6  
7000 21.8 71.2 315 6 3 9.9 5.4 | 23.0 73.4 315 6 3 9.7 5.3  
6750 22.5 72.5 315 6 3 9.6 5.3 | 23.7 74.7 315 6 3 9.8 5.4  
6500 23.3 73.9 315 6 3 11.2 6.2 | 24.5 76.1 315 5 3 10.7 5.8  
6250 24.1 75.4 310 6 3 12.3 6.7 | 25.3 77.5 310 5 3 11.4 6.2  
6000 25.0 77.0 310 6 3 9.9 5.4 | 26.1 79.0 310 5 3 9.6 5.3  
5750 25.8 78.4 310 6 3 13.4 7.3 | 26.8 80.2 305 5 3 10.3 5.6  
5500 27.1 80.8 310 6 3 19.2 10.6 | 27.7 81.9 310 5 3 13.1 7.2  
5250 28.4 83.1 310 6 3 14.6 8.0 | 28.6 83.5 315 5 3 11.1 6.1  
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.  
 
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.  
 
042613  
 
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