769  
UXUS97 KGJT 181247  
SRGGJT  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO  
0547 MST SUNDAY, FEBRUARY 18, 2018  
 
THIS FORECAST IS FOR SUNDAY, FEBRUARY 18, 2018:  
 
IF THE TRIGGER TEMPERATURE OF 54.8 F/12.7 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... GOOD  
MAXIMUM RATE OF LIFT........................ 469 FT/MIN (2.4 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 10984 FT MSL (6145 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 58.0 F/14.9 C  
TIME OF TRIGGER TEMPERATURE.................... 1245 MST  
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................. 7438 FT MSL (2598 FT AGL)  
THERMAL SOARING OUTLOOK FOR MONDAY 02/19....... GOOD  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
SUNRISE/SUNSET.................... 07:01:35 / 17:53:38 MST  
TOTAL POSSIBLE SUNSHINE........... 10 HR 52 MIN 4 SEC (652 MIN 4 SEC)  
ALTITUDE OF SUN AT 12:27:53 MST... 39.48 DEGREES  
 
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 02/18/2018 AT 0500 MST  
 
FREEZING LEVEL.................. 4863 FT MSL (24 FT AGL)  
ADDITIONAL FREEZING LEVEL....... 9146 FT MSL (4307 FT AGL)  
CONVECTIVE CONDENSATION LEVEL... 18694 FT MSL (13855 FT AGL)  
LIFTED CONDENSATION LEVEL....... 15090 FT MSL (10251 FT AGL)  
LIFTED INDEX.................... +6.7  
K INDEX......................... +1.3  
 
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 -64.4 -83.9 255 88 45 3.6 2.0 96.2 205.2 46.2 M M  
45000 -65.1 -85.2 265 79 41 3.6 2.0 69.0 156.3 33.2 M M  
40000 -63.0 -81.4 260 70 36 0.8 0.4 49.4 120.9 22.8 M M  
38000 -60.3 -76.5 255 72 37 5.1 2.8 44.7 112.4 20.3 M M  
36000 -56.2 -69.2 255 70 36 2.6 1.4 42.0 107.7 19.0 M M  
34000 -53.2 -63.8 260 68 35 3.0 1.7 38.0 100.4 16.7 M M  
32000 -49.6 -57.3 270 64 33 8.0 4.4 34.8 94.7 14.8 M M  
30000 -45.7 -50.3 260 57 29 9.0 5.0 31.2 88.2 12.5 M M  
29000 -43.0 -45.4 260 58 30 9.0 5.0 30.9 87.6 12.4 M M  
28000 -40.3 -40.5 260 58 30 9.0 4.9 30.6 87.1 12.4 M M  
27000 -37.7 -35.9 255 59 30 8.2 4.5 30.2 86.4 12.2 M M  
26000 -35.3 -31.5 255 59 31 8.2 4.5 29.6 85.2 11.9 M M  
25000 -32.8 -27.0 255 60 31 8.0 4.4 29.1 84.3 11.6 M M  
24000 -30.6 -23.1 255 64 33 6.6 3.6 28.1 82.7 11.0 M M  
23000 -28.6 -19.5 255 65 33 6.3 3.5 27.0 80.7 10.2 M M  
22000 -26.1 -15.0 250 65 33 9.2 5.1 26.5 79.6 9.9 M M  
21000 -23.4 -10.1 250 65 33 7.5 4.1 26.2 79.2 9.8 M M  
20000 -21.3 -6.3 250 62 32 7.2 3.9 25.3 77.5 9.1 M M  
19500 -20.3 -4.5 250 61 32 7.8 4.3 24.8 76.7 8.8 M M  
19000 -18.9 -2.0 250 60 31 9.6 5.2 24.7 76.4 8.7 M M  
18500 -17.5 0.5 250 59 31 9.5 5.2 24.7 76.4 8.7 M M  
18000 -16.2 2.8 250 58 30 7.9 4.3 24.5 76.0 8.6 M M  
17500 -15.3 4.5 245 56 29 4.4 2.4 23.8 74.9 8.1 M M  
17000 -14.2 6.4 245 54 28 5.9 3.2 22.6 72.6 7.0 M M  
16500 -13.2 8.2 240 52 27 6.2 3.4 22.0 71.7 6.6 M M  
16000 -12.8 9.0 240 51 26 0.8 0.4 20.9 69.7 5.6 M M  
15500 -12.1 10.2 250 49 25 8.1 4.4 20.1 68.2 4.9 M M  
15000 -11.0 12.2 255 48 25 7.5 4.1 19.7 67.5 4.5 M M  
14500 -9.9 14.2 250 46 23 7.4 4.1 19.3 66.8 4.2 M M  
14000 -8.8 16.2 250 44 23 7.5 4.1 18.9 66.1 3.9 M M  
13500 -7.6 18.3 250 45 23 8.0 4.4 18.6 65.5 3.6 M M  
13000 -6.4 20.5 255 45 23 7.8 4.3 18.3 65.0 3.4 M M  
12500 -5.2 22.6 255 46 23 7.6 4.2 18.0 64.4 3.1 M M  
12000 -4.1 24.6 255 45 23 8.2 4.5 17.6 63.7 2.8 M M  
11500 -3.4 25.9 245 38 19 0.2 0.1 16.8 62.3 2.1 M M  
11000 -4.0 24.8 235 31 16 -0.4 -0.2 14.7 58.5 -0.0 469 2.4  
10500 -3.2 26.2 235 29 15 6.9 3.8 14.0 57.1 -0.7 431 2.2  
10250 -2.6 27.3 240 28 15 10.0 5.5 13.9 57.1 -0.8 403 2.0  
10000 -1.9 28.6 240 27 14 8.7 4.8 13.9 57.0 -0.8 375 1.9  
9750 -1.3 29.7 240 26 14 7.4 4.1 13.8 56.8 -0.9 350 1.8  
9500 -0.8 30.6 240 25 13 6.7 3.7 13.5 56.4 -1.1 327 1.7  
9250 -0.2 31.6 240 24 12 6.9 3.8 13.3 56.0 -1.3 304 1.5  
9000 0.3 32.5 240 23 12 6.9 3.8 13.1 55.6 -1.6 282 1.4  
8750 0.8 33.4 240 21 11 6.9 3.8 12.9 55.2 -1.8 259 1.3  
8500 1.3 34.3 240 18 9 6.9 3.8 12.7 54.8 -2.0 236 1.2  
8250 1.8 35.2 245 16 8 6.9 3.8 12.5 54.4 -2.2 214 1.1  
8000 2.3 36.1 245 13 7 6.9 3.8 12.2 54.0 -2.4 191 1.0  
7750 2.8 37.0 230 11 6 6.9 3.8 12.0 53.6 -2.7 168 0.9  
7500 3.3 37.9 205 11 5 6.9 3.8 11.8 53.2 -2.9 146 0.7  
7250 3.8 38.8 185 12 6 6.9 3.8 11.6 52.8 -3.1 123 0.6  
7000 4.3 39.7 170 14 7 6.8 3.7 11.4 52.4 -3.4 100 0.5  
6750 4.9 40.8 165 17 9 7.3 4.0 11.1 52.0 -3.6 78 0.4  
6500 5.4 41.7 165 20 10 5.5 3.0 10.9 51.6 -3.8 55 0.3  
6250 5.9 42.6 165 23 12 12.2 6.7 10.7 51.2 -4.1 32 0.2  
6000 6.4 43.5 165 25 13 -12.9 -7.1 10.5 50.8 -4.3 9 0.0  
5750 4.1 39.4 165 22 11 -32.8 -18.0 7.4 45.3 -7.4 72 0.4  
5500 2.6 36.7 160 16 8 -6.8 -3.7 5.2 41.3 -9.6 108 0.5  
5250 2.7 36.9 155 11 6 6.6 3.6 4.6 40.2 -10.2 98 0.5  
5000 2.8 37.0 140 6 3 -10.2 -5.6 3.9 39.1 -10.9 89 0.5  
 
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *  
 
02/18/2018 AT 0800 MST | 02/18/2018 AT 1100 MST  
|  
K INDEX... +0.2 LI... +5.2 | K INDEX... +7.8 LI... +4.9  
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 -64.1 -83.4 265 84 43 3.2 1.8 | -64.1 -83.4 260 84 43 3.7 2.0  
45000 -59.3 -74.7 265 85 44 3.1 1.7 | -58.6 -73.5 265 91 47 3.6 2.0  
40000 -61.5 -78.7 260 86 44 -2.0 -1.1 | -61.5 -78.7 260 90 47 -2.6 -1.4  
38000 -61.1 -78.0 260 84 43 5.7 3.1 | -61.5 -78.7 260 89 46 5.8 3.2  
36000 -57.7 -71.9 260 79 40 5.8 3.2 | -57.9 -72.2 255 86 44 5.9 3.2  
34000 -54.2 -65.6 260 73 38 6.6 3.6 | -54.4 -65.9 255 82 42 6.6 3.6  
32000 -49.7 -57.5 260 71 37 7.5 4.1 | -49.9 -57.8 255 79 41 7.6 4.2  
30000 -45.3 -49.5 260 70 36 7.3 4.0 | -45.3 -49.5 255 76 39 7.6 4.2  
29000 -43.1 -45.6 260 69 36 7.1 3.9 | -43.0 -45.4 255 75 39 7.6 4.1  
28000 -40.5 -40.9 260 69 35 7.1 3.9 | -40.2 -40.4 255 74 38 7.6 4.1  
27000 -38.4 -37.1 255 69 35 7.1 3.9 | -37.9 -36.2 255 72 37 7.6 4.2  
26000 -36.1 -33.0 255 68 35 7.9 4.3 | -35.7 -32.3 255 71 37 7.5 4.1  
25000 -33.7 -28.7 255 67 35 7.9 4.3 | -33.5 -28.3 255 70 36 7.5 4.1  
24000 -31.3 -24.3 255 66 34 7.9 4.3 | -31.2 -24.2 250 69 35 7.5 4.1  
23000 -29.0 -20.2 255 65 33 7.8 4.3 | -29.1 -20.4 250 67 34 7.1 3.9  
22000 -26.7 -16.1 255 62 32 7.8 4.3 | -26.9 -16.4 250 64 33 7.1 3.9  
21000 -24.4 -11.9 260 60 31 7.6 4.2 | -24.8 -12.6 250 62 32 7.1 3.9  
20000 -22.4 -8.3 260 58 30 6.4 3.5 | -22.8 -9.0 255 59 30 6.8 3.7  
19500 -21.4 -6.5 260 56 29 6.4 3.5 | -21.8 -7.2 255 58 30 6.8 3.7  
19000 -20.5 -4.9 255 55 28 6.4 3.5 | -20.7 -5.3 255 57 29 6.8 3.7  
18500 -19.5 -3.1 255 53 27 6.4 3.5 | -19.7 -3.5 255 55 28 6.8 3.7  
18000 -18.5 -1.3 255 52 27 7.1 3.9 | -18.7 -1.7 255 54 28 6.8 3.8  
17500 -17.5 0.5 255 50 26 7.0 3.8 | -17.7 0.1 255 53 27 6.9 3.8  
17000 -16.4 2.5 255 49 25 7.1 3.9 | -16.7 1.9 255 52 27 7.0 3.8  
16500 -15.3 4.5 255 48 25 7.1 3.9 | -15.6 3.9 255 50 26 7.1 3.9  
16000 -14.3 6.3 255 47 24 7.1 3.9 | -14.6 5.7 255 49 25 7.2 3.9  
15500 -13.2 8.2 250 46 24 7.1 3.9 | -13.5 7.7 255 47 24 7.4 4.0  
15000 -12.1 10.2 250 45 23 7.2 3.9 | -12.4 9.7 250 46 24 7.5 4.1  
14500 -11.1 12.0 250 44 23 6.8 3.7 | -11.4 11.5 250 45 23 6.3 3.4  
14000 -10.1 13.8 250 43 22 6.9 3.8 | -10.5 13.1 250 44 23 6.3 3.5  
13500 -8.6 16.5 250 42 22 6.5 3.6 | -9.3 15.3 250 43 22 4.6 2.5  
13000 -7.7 18.1 245 41 21 6.5 3.6 | -8.6 16.5 250 42 22 4.7 2.6  
12500 -6.7 19.9 245 41 21 6.0 3.3 | -7.9 17.8 250 41 21 4.7 2.6  
12000 -5.9 21.4 245 41 21 6.1 3.3 | -7.2 19.0 250 40 21 4.6 2.5  
11500 -5.0 23.0 245 41 21 5.7 3.1 | -6.3 20.7 250 39 20 7.1 3.9  
11000 -4.1 24.6 245 41 21 5.8 3.2 | -5.3 22.5 250 39 20 6.9 3.8  
10500 -3.2 26.2 245 41 21 6.5 3.6 | -4.3 24.3 245 40 20 6.1 3.3  
10250 -2.7 27.1 245 42 21 7.3 4.0 | -3.9 25.0 245 40 21 6.8 3.7  
10000 -2.1 28.2 245 42 21 9.1 5.0 | -3.3 26.1 245 41 21 8.2 4.5  
9750 -1.4 29.5 245 42 21 8.2 4.5 | -2.7 27.1 245 40 21 8.0 4.4  
9500 -0.9 30.4 240 41 21 7.2 4.0 | -2.2 28.0 240 39 20 7.3 4.0  
9250 -0.4 31.3 240 40 21 7.6 4.2 | -1.6 29.1 240 38 19 7.8 4.3  
9000 0.2 32.4 240 40 21 7.0 3.9 | -1.1 30.0 235 37 19 5.6 3.1  
8750 0.7 33.3 240 39 20 6.4 3.5 | -0.8 30.6 235 35 18 5.5 3.0  
8500 1.1 34.0 235 38 19 6.3 3.5 | -0.3 31.5 235 31 16 7.3 4.0  
8250 1.6 34.9 235 37 19 6.6 3.6 | 0.2 32.4 230 28 15 7.0 3.8  
8000 2.1 35.8 230 35 18 6.2 3.4 | 0.7 33.3 225 25 13 6.6 3.6  
7750 2.4 36.3 225 34 17 3.4 1.9 | 1.2 34.2 225 23 12 6.8 3.7  
7500 2.6 36.7 225 32 17 2.1 1.1 | 1.8 35.2 225 20 10 7.3 4.0  
7250 2.8 37.0 220 31 16 2.0 1.1 | 2.3 36.1 220 18 9 7.8 4.3  
7000 2.9 37.2 215 29 15 0.2 0.1 | 2.9 37.2 220 17 9 9.7 5.3  
6750 2.8 37.0 205 27 14 -1.5 -0.8 | 3.7 38.7 220 16 8 9.9 5.5  
6500 2.7 36.9 200 24 12 -1.7 -1.0 | 4.4 39.9 220 15 8 9.4 5.2  
6250 2.5 36.5 190 22 11 -4.3 -2.4 | 5.1 41.2 220 14 7 9.9 5.4  
6000 2.0 35.6 185 19 10 -6.2 -3.4 | 5.9 42.6 215 13 7 10.3 5.6  
5750 1.6 34.9 175 15 8 -3.8 -2.1 | 6.6 43.9 215 13 6 10.0 5.5  
5500 1.4 34.5 165 11 6 -2.6 -1.4 | 7.4 45.3 215 11 6 10.3 5.7  
5250 1.2 34.2 165 10 5 -2.7 -1.5 | 8.2 46.8 220 11 6 11.6 6.3  
5000 M M M M M M M | M M M M M M M  
 
02/18/2018 AT 1400 MST | 02/18/2018 AT 1700 MST  
|  
K INDEX... +11.7 LI... +1.6 | K INDEX... +16.7 LI... +0.5  
CAPE... 0.0 CIN... -0.1 | CAPE... +8.0 CIN... -1.8  
|  
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 -64.1 -83.4 260 86 44 3.8 2.1 | -63.4 -82.1 260 93 48 3.5 1.9  
45000 -58.4 -73.1 260 94 48 3.7 2.0 | -58.2 -72.8 260 97 50 3.4 1.9  
40000 -60.1 -76.2 260 96 49 -1.8 -1.0 | -58.6 -73.5 255 98 50 -0.8 -0.4  
38000 -59.9 -75.8 255 96 49 5.3 2.9 | -58.5 -73.3 255 98 50 4.5 2.5  
36000 -56.7 -70.1 255 94 49 5.4 3.0 | -55.8 -68.4 250 98 50 4.1 2.2  
34000 -53.4 -64.1 250 93 48 6.0 3.3 | -53.3 -63.9 250 97 50 4.5 2.5  
32000 -49.2 -56.6 250 90 46 7.1 3.9 | -49.4 -56.9 250 92 47 6.7 3.7  
30000 -45.0 -49.0 250 88 45 7.3 4.0 | -45.4 -49.7 250 85 44 6.9 3.8  
29000 -42.7 -44.9 250 85 44 7.6 4.2 | -43.2 -45.8 250 84 43 7.4 4.1  
28000 -40.4 -40.7 250 83 43 7.6 4.2 | -41.0 -41.8 250 82 42 7.4 4.1  
27000 -38.1 -36.6 250 81 42 7.6 4.1 | -38.7 -37.7 250 81 42 7.4 4.0  
26000 -35.9 -32.6 250 78 40 6.9 3.8 | -36.6 -33.9 255 79 41 6.4 3.5  
25000 -33.9 -29.0 250 77 39 6.9 3.8 | -34.7 -30.5 255 78 40 6.5 3.6  
24000 -31.8 -25.2 250 75 38 6.9 3.8 | -32.8 -27.0 255 77 39 6.5 3.6  
23000 -29.7 -21.5 250 72 37 6.7 3.7 | -30.8 -23.4 255 75 39 7.1 3.9  
22000 -27.2 -17.0 250 68 35 6.7 3.7 | -28.7 -19.7 255 72 37 7.1 3.9  
21000 -25.2 -13.4 250 65 33 6.8 3.7 | -26.5 -15.7 255 69 36 7.1 3.9  
20000 -23.2 -9.8 250 62 32 6.9 3.8 | -23.9 -11.0 255 65 34 6.9 3.8  
19500 -22.2 -8.0 250 60 31 6.9 3.8 | -22.9 -9.2 255 64 33 6.9 3.8  
19000 -21.1 -6.0 250 59 30 6.9 3.8 | -21.9 -7.4 255 62 32 6.9 3.8  
18500 -20.1 -4.2 250 57 30 6.9 3.8 | -20.9 -5.6 250 60 31 6.9 3.8  
18000 -19.1 -2.4 250 56 29 6.6 3.6 | -19.8 -3.6 250 58 30 6.9 3.8  
17500 -18.1 -0.6 245 55 28 6.7 3.7 | -18.8 -1.8 250 56 29 6.9 3.8  
17000 -17.1 1.2 245 53 27 6.7 3.7 | -17.8 -0.0 250 54 28 6.9 3.8  
16500 -16.1 3.0 245 52 27 6.7 3.7 | -16.8 1.8 250 52 27 7.0 3.8  
16000 -15.1 4.8 245 51 26 6.6 3.6 | -15.7 3.7 250 50 26 7.0 3.8  
15500 -14.2 6.4 245 50 26 6.2 3.4 | -14.7 5.5 250 48 25 7.2 3.9  
15000 -13.3 8.1 240 48 25 6.3 3.4 | -13.6 7.5 250 46 24 7.2 4.0  
14500 -12.4 9.7 240 47 24 6.1 3.4 | -12.6 9.3 250 44 23 6.6 3.6  
14000 -11.5 11.3 240 45 23 6.1 3.4 | -11.7 10.9 245 44 22 6.5 3.6  
13500 -10.5 13.1 240 43 22 6.5 3.5 | -10.7 12.7 245 43 22 7.1 3.9  
13000 -9.6 14.7 245 42 21 6.5 3.6 | -9.6 14.7 240 43 22 7.4 4.0  
12500 -8.6 16.5 240 40 21 7.1 3.9 | -8.6 16.5 240 44 23 8.2 4.5  
12000 -7.6 18.3 240 38 20 7.2 3.9 | -7.3 18.9 235 43 22 8.7 4.8  
11500 -6.5 20.3 240 36 19 8.4 4.6 | -6.0 21.2 235 43 22 8.6 4.7  
11000 -5.2 22.6 235 34 18 8.9 4.9 | -4.8 23.4 230 42 22 8.6 4.7  
10500 -3.9 25.0 230 32 17 8.7 4.8 | -3.5 25.7 225 41 21 9.3 5.1  
10250 -3.3 26.1 230 30 16 8.6 4.7 | -2.8 27.0 225 40 21 9.7 5.3  
10000 -2.6 27.3 230 29 15 8.3 4.5 | -2.1 28.2 225 40 20 8.5 4.6  
9750 -2.0 28.4 225 28 14 8.7 4.8 | -1.5 29.3 225 39 20 8.2 4.5  
9500 -1.4 29.5 225 27 14 9.7 5.3 | -0.9 30.4 225 38 20 9.2 5.0  
9250 -0.6 30.9 225 26 14 10.5 5.7 | -0.1 31.8 220 37 19 10.2 5.6  
9000 0.1 32.2 225 25 13 8.4 4.6 | 0.6 33.1 220 36 19 8.5 4.7  
8750 0.7 33.3 225 25 13 8.4 4.6 | 1.2 34.2 220 36 18 7.7 4.2  
8500 1.4 34.5 225 24 12 10.6 5.8 | 1.8 35.2 220 35 18 9.3 5.1  
8250 2.2 36.0 225 23 12 11.0 6.0 | 2.5 36.5 220 34 17 10.3 5.6  
8000 3.0 37.4 225 23 12 8.8 4.8 | 3.3 37.9 220 32 17 8.3 4.5  
7750 3.6 38.5 225 22 12 8.4 4.6 | 3.8 38.8 220 32 16 7.2 4.0  
7500 4.3 39.7 225 22 11 10.3 5.7 | 4.4 39.9 220 30 16 8.9 4.9  
7250 5.1 41.2 225 21 11 9.9 5.4 | 5.1 41.2 220 29 15 8.7 4.8  
7000 5.8 42.4 225 21 11 9.8 5.4 | 5.7 42.3 215 28 14 9.4 5.1  
6750 6.5 43.7 225 20 10 9.9 5.4 | 6.4 43.5 215 26 14 9.1 5.0  
6500 7.3 45.1 225 20 10 10.1 5.6 | 7.1 44.8 215 24 12 8.3 4.6  
6250 8.0 46.4 225 19 10 10.3 5.7 | 7.7 45.9 215 22 11 8.6 4.7  
6000 8.8 47.8 225 18 9 9.4 5.2 | 8.3 46.9 215 20 10 8.3 4.5  
5750 9.6 49.3 225 17 9 13.9 7.6 | 8.9 48.0 215 19 10 8.1 4.5  
5500 11.0 51.8 225 16 8 23.9 13.1 | 9.5 49.1 215 17 9 8.7 4.8  
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.  
 
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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