580  
UXUS97 KGJT 301235  
SRGGJT  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO  
0635 MDT SUNDAY, APRIL 30, 2017  
 
THIS FORECAST IS FOR SUNDAY, APRIL 30, 2017:  
 
IF THE TRIGGER TEMPERATURE OF 45.8 F/7.7 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... EXCELLENT  
MAXIMUM RATE OF LIFT........................ 854 FT/MIN (4.3 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 16004 FT MSL (11165 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 63.0 F/17.7 C  
TIME OF TRIGGER TEMPERATURE.................... 1145 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................. 13517 FT MSL (8678 FT AGL)  
THERMAL SOARING OUTLOOK FOR MONDAY 05/01....... EXCELLENT  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
SUNRISE/SUNSET.................... 06:16:50 / 20:05:34 MDT  
TOTAL POSSIBLE SUNSHINE........... 13 HR 48 MIN 44 SEC (828 MIN 44 SEC)  
ALTITUDE OF SUN AT 13:11:22 MDT... 65.89 DEGREES  
 
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 04/30/2017 AT 0600 MDT  
 
FREEZING LEVEL.................. 7074 FT MSL (2235 FT AGL)  
CONVECTIVE CONDENSATION LEVEL... 15888 FT MSL (11049 FT AGL)  
LIFTED CONDENSATION LEVEL....... 16274 FT MSL (11435 FT AGL)  
LIFTED INDEX.................... +6.5  
K INDEX......................... -11.6  
 
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 -58.5 -73.3 315 39 20 3.5 1.9 104.7 220.5 49.7 M M  
45000 -53.9 -65.0 320 47 24 2.3 1.2 86.4 187.4 42.2 M M  
40000 -49.3 -56.7 305 57 29 -15.5 -8.5 70.7 159.3 34.8 M M  
38000 -56.2 -69.2 340 58 30 6.0 3.3 51.4 124.6 22.9 M M  
36000 -52.3 -62.1 360 55 28 7.3 4.0 48.4 119.1 21.4 M M  
34000 -51.3 -60.3 350 63 32 4.5 2.5 41.5 106.7 17.1 M M  
32000 -50.2 -58.4 350 74 38 9.1 5.0 33.7 92.7 12.0 M M  
30000 -45.1 -49.2 355 76 39 7.6 4.2 32.7 90.9 11.6 M M  
29000 -42.9 -45.2 355 72 37 7.6 4.2 31.8 89.3 11.0 M M  
28000 -40.6 -41.1 355 69 36 7.9 4.3 31.0 87.8 10.6 M M  
27000 -38.0 -36.4 360 66 34 8.9 4.9 30.6 87.0 10.3 M M  
26000 -35.3 -31.5 360 62 32 8.9 4.9 30.2 86.4 10.2 M M  
25000 -32.6 -26.7 360 59 30 8.9 4.9 30.0 86.1 10.2 M M  
24000 -30.0 -22.0 360 57 29 8.9 4.9 29.7 85.4 10.0 M M  
23000 -27.3 -17.1 360 57 29 8.9 4.9 29.2 84.6 9.8 M M  
22000 -24.6 -12.3 360 56 29 8.9 4.9 28.9 84.0 9.6 M M  
21000 -22.0 -7.6 355 56 29 7.0 3.8 28.6 83.5 9.5 M M  
20000 -20.3 -4.5 355 56 29 5.6 3.1 27.2 80.9 8.4 M M  
19500 -19.3 -2.7 360 54 28 7.6 4.2 26.6 79.9 7.9 M M  
19000 -18.2 -0.8 010 51 26 7.7 4.2 26.2 79.2 7.6 M M  
18500 -17.2 1.0 010 49 25 4.2 2.3 25.6 78.1 7.2 M M  
18000 -16.6 2.1 005 45 23 0.7 0.4 24.7 76.4 6.4 M M  
17500 -17.7 0.1 355 42 21 -0.7 -0.4 20.9 69.6 3.2 M M  
17000 -17.3 0.9 350 39 20 2.1 1.1 19.6 67.3 2.1 M M  
16500 -17.0 1.4 350 36 19 2.2 1.2 18.3 65.0 1.0 M M  
16000 -16.7 1.9 350 34 17 3.6 2.0 17.0 62.5 -0.2 850 4.3  
15500 -15.7 3.7 345 31 16 7.5 4.1 16.4 61.6 -0.7 805 4.1  
15000 -14.6 5.7 345 29 15 7.4 4.1 16.1 60.9 -1.1 757 3.8  
14500 -13.5 7.7 350 26 13 6.7 3.7 15.7 60.2 -1.4 709 3.6  
14000 -12.8 9.0 350 23 12 3.8 2.1 14.9 58.7 -2.2 674 3.4  
13500 -12.3 9.9 360 22 11 4.0 2.2 13.9 57.0 -3.1 642 3.3  
13000 -11.7 10.9 005 22 11 3.8 2.1 13.0 55.3 -4.0 610 3.1  
12500 -11.1 12.0 020 25 13 1.4 0.7 12.0 53.6 -4.9 578 2.9  
12000 -11.1 12.0 030 28 14 3.5 1.9 10.5 51.0 -6.4 563 2.9  
11500 -10.2 13.6 025 28 14 8.5 4.7 10.0 50.0 -7.0 520 2.6  
11000 -8.9 16.0 020 28 15 9.5 5.2 9.9 49.7 -7.2 466 2.4  
10500 -7.5 18.5 020 29 15 9.0 4.9 9.8 49.6 -7.3 409 2.1  
10250 -6.8 19.8 015 29 15 11.1 6.1 9.8 49.6 -7.3 380 1.9  
10000 -6.0 21.2 010 29 15 6.9 3.8 9.9 49.8 -7.3 350 1.8  
9750 -5.8 21.6 010 27 14 0.1 0.1 9.3 48.7 -7.9 338 1.7  
9500 -5.7 21.7 010 24 12 2.8 1.5 8.6 47.5 -8.5 328 1.7  
9250 -5.4 22.3 010 22 11 7.0 3.8 8.2 46.8 -8.9 309 1.6  
9000 -4.8 23.4 010 19 10 8.3 4.6 8.1 46.6 -9.0 284 1.4  
8750 -4.2 24.4 010 17 9 8.0 4.4 8.0 46.3 -9.2 259 1.3  
8500 -3.6 25.5 010 15 8 8.1 4.4 7.8 46.1 -9.3 233 1.2  
8250 -3.0 26.6 005 13 7 8.0 4.4 7.7 45.9 -9.5 208 1.1  
8000 -2.4 27.7 005 11 6 8.0 4.4 7.6 45.7 -9.6 182 0.9  
7750 -1.8 28.8 005 10 5 8.0 4.4 7.5 45.4 -9.8 157 0.8  
7500 -1.2 29.8 005 8 4 8.0 4.4 7.3 45.2 -9.9 131 0.7  
7250 -0.6 30.9 010 7 3 8.0 4.4 7.2 45.0 -10.1 106 0.5  
7000 0.1 32.2 010 5 3 8.0 4.4 7.1 44.7 -10.2 80 0.4  
6750 0.7 33.3 360 5 2 8.0 4.4 6.9 44.5 -10.4 55 0.3  
6500 1.3 34.3 340 4 2 8.0 4.4 6.8 44.2 -10.6 30 0.2  
6250 1.9 35.4 325 4 2 8.0 4.4 6.7 44.0 -10.7 4 0.0  
6000 2.5 36.5 310 5 2 8.0 4.4 6.5 43.8 -10.9 M M  
5750 3.1 37.6 310 4 2 8.1 4.4 6.4 43.5 -11.1 M M  
5500 3.7 38.7 330 3 2 7.9 4.3 6.3 43.3 -11.2 M M  
5250 4.2 39.6 360 2 1 6.0 3.3 6.1 42.9 -11.4 M M  
5000 4.2 39.6 030 3 1 -10.4 -5.7 5.3 41.6 -12.2 M M  
 
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *  
 
04/30/2017 AT 0900 MDT | 04/30/2017 AT 1200 MDT  
|  
K INDEX... -11.8 LI... +9.2 | K INDEX... -3.0 LI... +8.0  
CAPE... 0.0 CIN... 0.0 | CAPE... +0.3 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 -56.2 -69.2 310 34 17 1.3 0.7 | -57.1 -70.8 310 36 19 1.6 0.9  
45000 -54.2 -65.6 320 46 24 0.6 0.3 | -54.7 -66.5 320 46 23 -1.2 -0.6  
40000 -56.2 -69.2 340 55 28 -1.3 -0.7 | -56.7 -70.1 335 57 30 -1.3 -0.7  
38000 -56.0 -68.8 345 59 30 1.9 1.0 | -56.2 -69.2 335 61 31 2.6 1.4  
36000 -54.8 -66.6 345 64 33 1.9 1.0 | -54.6 -66.3 335 63 32 2.6 1.4  
34000 -53.1 -63.6 350 67 35 8.3 4.5 | -52.5 -62.5 340 64 33 8.1 4.4  
32000 -48.5 -55.3 350 63 33 7.8 4.3 | -47.8 -54.0 340 63 32 7.8 4.3  
30000 -43.8 -46.8 350 59 30 7.2 3.9 | -42.4 -44.3 345 58 30 8.5 4.7  
29000 -41.7 -43.1 350 54 28 7.2 4.0 | -39.9 -39.8 340 53 27 8.5 4.7  
28000 -39.0 -38.2 355 49 25 7.2 4.0 | -37.3 -35.1 340 47 24 8.5 4.7  
27000 -36.8 -34.2 355 45 23 8.0 4.4 | -34.8 -30.6 340 42 22 7.0 3.8  
26000 -34.3 -29.7 355 43 22 8.2 4.5 | -32.9 -27.2 335 39 20 6.5 3.6  
25000 -31.8 -25.2 355 41 21 8.2 4.5 | -31.0 -23.8 335 36 19 6.5 3.6  
24000 -29.3 -20.7 355 40 20 8.2 4.5 | -29.0 -20.2 335 33 17 6.9 3.8  
23000 -26.9 -16.4 355 39 20 8.2 4.5 | -26.8 -16.2 335 33 17 7.4 4.1  
22000 -24.5 -12.1 355 39 20 8.2 4.5 | -24.6 -12.3 335 33 17 7.4 4.1  
21000 -22.1 -7.8 355 39 20 7.2 3.9 | -22.4 -8.3 335 33 17 7.6 4.1  
20000 -20.0 -4.0 355 39 20 6.9 3.8 | -20.1 -4.2 335 32 17 7.6 4.2  
19500 -18.9 -2.0 355 38 20 6.9 3.8 | -19.0 -2.2 340 32 17 7.6 4.2  
19000 -17.9 -0.2 355 38 20 6.9 3.8 | -17.8 -0.0 340 32 17 7.6 4.2  
18500 -16.9 1.6 360 38 19 6.7 3.7 | -16.7 1.9 340 32 16 7.2 3.9  
18000 -15.9 3.4 355 38 19 6.5 3.6 | -15.7 3.7 340 32 16 6.9 3.8  
17500 -14.9 5.2 355 38 20 6.5 3.6 | -14.7 5.5 340 32 17 6.9 3.8  
17000 -14.0 6.8 355 38 20 5.5 3.0 | -13.7 7.3 340 32 17 5.8 3.2  
16500 -13.2 8.2 355 38 19 5.7 3.1 | -12.8 9.0 340 32 17 5.9 3.2  
16000 -12.4 9.7 355 38 19 4.3 2.4 | -11.9 10.6 345 33 17 5.9 3.2  
15500 -11.8 10.8 355 37 19 3.9 2.1 | -11.1 12.0 345 33 17 5.8 3.2  
15000 -11.2 11.8 355 37 19 2.4 1.3 | -10.2 13.6 345 33 17 5.1 2.8  
14500 -11.1 12.0 355 35 18 0.4 0.2 | -9.2 15.4 350 33 17 4.4 2.4  
14000 -11.1 12.0 350 33 17 0.4 0.2 | -8.7 16.3 350 33 17 1.6 0.9  
13500 -11.0 12.2 355 29 15 0.9 0.5 | -8.5 16.7 350 32 17 1.2 0.6  
13000 -10.7 12.7 355 27 14 4.2 2.3 | -8.4 16.9 355 31 16 0.5 0.3  
12500 -10.0 14.0 360 26 13 5.4 2.9 | -8.4 16.9 355 28 14 0.4 0.2  
12000 -9.1 15.6 360 24 13 6.8 3.7 | -8.3 17.1 360 24 12 3.1 1.7  
11500 -8.1 17.4 005 24 12 7.3 4.0 | -7.7 18.1 005 20 10 4.3 2.3  
11000 -7.0 19.4 005 24 12 7.2 3.9 | -7.1 19.2 010 17 9 6.1 3.4  
10500 -6.0 21.2 005 24 13 7.9 4.3 | -6.1 21.0 010 14 7 7.4 4.0  
10250 -5.5 22.1 005 25 13 3.9 2.2 | -5.7 21.7 010 13 7 3.7 2.0  
10000 -5.4 22.3 005 25 13 3.9 2.1 | -5.5 22.1 005 11 6 5.3 2.9  
9750 -4.9 23.2 005 25 13 7.7 4.2 | -4.8 23.4 005 10 5 9.9 5.5  
9500 -4.3 24.3 005 25 13 7.2 3.9 | -4.1 24.6 360 9 5 9.1 5.0  
9250 -3.8 25.2 005 25 13 5.6 3.1 | -3.5 25.7 360 8 4 7.7 4.2  
9000 -3.5 25.7 005 24 13 3.8 2.1 | -3.0 26.6 355 7 4 7.4 4.1  
8750 -3.2 26.2 005 23 12 4.8 2.6 | -2.3 27.9 350 6 3 9.6 5.3  
8500 -2.9 26.8 005 21 11 4.7 2.6 | -1.6 29.1 345 6 3 9.5 5.2  
8250 -2.5 27.5 005 19 10 4.4 2.4 | -0.9 30.4 340 5 3 8.9 4.9  
8000 -2.2 28.0 005 16 8 4.3 2.3 | -0.2 31.6 340 5 3 8.9 4.9  
7750 -1.9 28.6 005 13 7 4.4 2.4 | 0.4 32.7 335 5 2 9.5 5.2  
7500 -1.5 29.3 010 10 5 4.0 2.2 | 1.2 34.2 330 4 2 10.0 5.5  
7250 -1.3 29.7 010 8 4 3.7 2.0 | 1.9 35.4 330 4 2 10.5 5.8  
7000 -1.0 30.2 005 6 3 3.4 1.9 | 2.7 36.9 325 4 2 10.2 5.6  
6750 -0.7 30.7 005 4 2 4.9 2.7 | 3.5 38.3 320 4 2 10.0 5.5  
6500 -0.2 31.6 005 3 2 8.9 4.9 | 4.2 39.6 315 4 2 10.7 5.9  
6250 0.5 32.9 360 3 1 10.7 5.9 | 5.1 41.2 315 4 2 12.1 6.7  
6000 1.3 34.3 360 2 1 8.9 4.9 | 6.0 42.8 310 3 2 9.4 5.2  
5750 1.9 35.4 355 2 1 10.0 5.5 | 6.7 44.1 305 3 2 12.5 6.8  
5500 2.8 37.0 355 2 1 12.6 6.9 | 7.9 46.2 310 3 2 18.3 10.0  
5250 3.7 38.7 355 2 1 10.5 5.8 | 9.1 48.4 315 4 2 13.7 7.5  
5000 M M M M M M M | M M M M M M M  
 
04/30/2017 AT 1500 MDT | 04/30/2017 AT 1800 MDT  
|  
K INDEX... +6.4 LI... +6.4 | K INDEX... +11.3 LI... +4.2  
CAPE... +0.3 CIN... -0.3 | 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 -58.1 -72.6 315 38 20 0.9 0.5 | -58.4 -73.1 315 37 19 0.1 0.1  
45000 -56.7 -70.1 325 47 24 -0.7 -0.4 | -58.3 -72.9 325 47 24 -0.9 -0.5  
40000 -57.7 -71.9 335 61 31 -0.6 -0.4 | -59.4 -74.9 340 73 38 -0.8 -0.4  
38000 -56.6 -69.9 335 65 34 3.6 2.0 | -57.5 -71.5 340 79 41 5.6 3.1  
36000 -54.5 -66.1 335 68 35 3.6 2.0 | -54.1 -65.4 340 83 43 5.6 3.1  
34000 -51.8 -61.2 340 70 36 8.1 4.4 | -50.3 -58.5 340 85 44 8.3 4.6  
32000 -47.0 -52.6 340 67 35 8.0 4.4 | -45.3 -49.5 340 82 42 8.4 4.6  
30000 -41.5 -42.7 340 63 32 8.1 4.4 | -39.7 -39.5 345 76 39 8.1 4.4  
29000 -39.1 -38.4 340 58 30 8.1 4.4 | -37.2 -35.0 345 70 36 8.1 4.4  
28000 -36.7 -34.1 340 53 27 8.1 4.4 | -34.8 -30.6 345 65 33 8.1 4.4  
27000 -34.3 -29.7 340 49 25 8.1 4.4 | -32.4 -26.3 345 59 30 7.6 4.2  
26000 -31.8 -25.2 335 46 24 8.1 4.4 | -30.2 -22.4 340 52 27 7.6 4.2  
25000 -29.4 -20.9 330 43 22 8.1 4.4 | -27.9 -18.2 330 46 23 7.6 4.2  
24000 -27.0 -16.6 325 41 21 6.7 3.7 | -25.6 -14.1 320 40 21 6.1 3.3  
23000 -25.5 -13.9 325 41 21 5.2 2.9 | -24.2 -11.6 320 41 21 4.8 2.7  
22000 -23.9 -11.0 325 41 21 5.2 2.9 | -22.8 -9.0 315 42 22 4.8 2.7  
21000 -22.3 -8.1 325 40 21 7.5 4.1 | -21.3 -6.3 315 43 22 4.8 2.7  
20000 -19.9 -3.8 330 37 19 7.9 4.3 | -19.9 -3.8 320 40 21 4.9 2.7  
19500 -18.7 -1.7 330 35 18 7.9 4.3 | -19.2 -2.6 320 39 20 4.9 2.7  
19000 -17.5 0.5 330 33 17 7.9 4.3 | -18.5 -1.3 325 37 19 4.9 2.7  
18500 -16.4 2.5 335 32 16 7.6 4.2 | -17.8 -0.0 325 36 19 6.0 3.3  
18000 -15.3 4.5 335 32 17 7.4 4.1 | -16.8 1.8 330 36 18 6.6 3.6  
17500 -14.2 6.4 335 33 17 7.4 4.1 | -15.8 3.6 330 36 18 6.7 3.7  
17000 -13.3 8.1 335 33 17 5.3 2.9 | -14.9 5.2 335 35 18 5.9 3.2  
16500 -12.5 9.5 335 33 17 5.6 3.0 | -14.0 6.8 335 35 18 6.0 3.3  
16000 -11.7 10.9 335 33 17 4.1 2.3 | -13.2 8.2 335 34 18 4.8 2.6  
15500 -11.1 12.0 340 33 17 3.8 2.1 | -12.5 9.5 335 33 17 4.7 2.6  
15000 -10.6 12.9 340 33 17 3.4 1.9 | -11.8 10.8 340 32 16 5.2 2.9  
14500 -10.1 13.8 340 32 17 2.9 1.6 | -11.0 12.2 340 30 15 5.7 3.1  
14000 -9.5 14.9 345 30 16 3.2 1.8 | -9.6 14.7 340 27 14 6.6 3.6  
13500 -9.0 15.8 345 27 14 3.2 1.8 | -8.7 16.3 335 24 12 6.5 3.6  
13000 -8.5 16.7 345 24 12 4.3 2.4 | -7.6 18.3 335 22 11 7.8 4.3  
12500 -7.8 18.0 345 21 11 4.6 2.5 | -6.4 20.5 335 20 10 8.1 4.5  
12000 -7.1 19.2 345 18 9 6.5 3.6 | -5.2 22.6 330 18 9 8.5 4.6  
11500 -6.1 21.0 345 16 8 7.2 3.9 | -3.9 25.0 325 17 9 8.6 4.7  
11000 -5.0 23.0 340 14 7 8.1 4.4 | -2.6 27.3 325 15 8 8.6 4.7  
10500 -3.8 25.2 335 12 6 9.2 5.0 | -1.3 29.7 315 14 7 9.4 5.2  
10250 -3.1 26.4 330 11 6 4.9 2.7 | -0.7 30.7 315 13 7 5.5 3.0  
10000 -2.9 26.8 325 10 5 5.4 3.0 | -0.4 31.3 310 13 7 5.8 3.2  
9750 -2.2 28.0 320 9 5 10.0 5.5 | 0.3 32.5 305 12 6 9.9 5.4  
9500 -1.5 29.3 315 9 4 9.0 4.9 | 1.0 33.8 300 12 6 9.1 5.0  
9250 -0.9 30.4 305 8 4 8.7 4.7 | 1.6 34.9 295 11 6 8.1 4.5  
9000 -0.3 31.5 300 8 4 8.2 4.5 | 2.2 36.0 290 11 6 7.0 3.9  
8750 0.4 32.7 295 7 4 8.6 4.7 | 2.7 36.9 285 11 5 7.6 4.2  
8500 1.0 33.8 290 7 4 8.5 4.7 | 3.3 37.9 280 10 5 7.4 4.1  
8250 1.7 35.1 280 7 4 9.9 5.5 | 3.8 38.8 275 10 5 7.9 4.3  
8000 2.5 36.5 280 7 3 10.7 5.9 | 4.4 39.9 270 10 5 8.4 4.6  
7750 3.2 37.8 275 7 3 10.2 5.6 | 5.1 41.2 270 9 5 8.3 4.6  
7500 4.0 39.2 270 7 3 10.0 5.5 | 5.7 42.3 270 9 5 9.1 5.0  
7250 4.7 40.5 270 7 3 9.7 5.3 | 6.4 43.5 265 9 5 10.6 5.8  
7000 5.5 41.9 270 6 3 9.8 5.4 | 7.2 45.0 265 9 5 10.5 5.8  
6750 6.2 43.2 265 6 3 10.5 5.8 | 8.0 46.4 265 9 5 9.0 5.0  
6500 7.0 44.6 265 6 3 11.0 6.0 | 8.7 47.7 265 9 5 10.0 5.5  
6250 7.9 46.2 260 6 3 11.6 6.4 | 9.5 49.1 265 9 5 11.4 6.3  
6000 8.7 47.7 260 6 3 9.7 5.3 | 10.3 50.5 260 9 4 10.5 5.8  
5750 9.4 48.9 255 6 3 11.7 6.4 | 11.1 52.0 260 8 4 10.0 5.5  
5500 10.5 50.9 260 6 3 16.8 9.2 | 11.8 53.2 260 8 4 10.4 5.7  
5250 11.7 53.1 265 6 3 14.8 8.1 | 12.6 54.7 265 8 4 10.9 6.0  
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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