205  
UXUS97 KGJT 261248  
SRGGJT  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO  
0648 MDT WEDNESDAY, APRIL 26, 2017  
 
THIS FORECAST IS FOR WEDNESDAY, APRIL 26, 2017:  
 
IF THE TRIGGER TEMPERATURE OF 49.5 F/9.7 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... GOOD  
MAXIMUM RATE OF LIFT........................ 400 FT/MIN (2.0 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 14694 FT MSL (9855 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 60.0 F/16.0 C  
TIME OF TRIGGER TEMPERATURE.................... 1015 MDT  
TIME OF OVERDEVELOPMENT........................ 1500 MDT  
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... BROKEN/OVERCAST OPAQUE MIDDLE  
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS  
HEIGHT OF THE -3 THERMAL INDEX................. 12910 FT MSL (8071 FT AGL)  
THERMAL SOARING OUTLOOK FOR THURSDAY 04/27..... FAIR  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
SUNRISE/SUNSET.................... 06:21:51 / 20:01:40 MDT  
TOTAL POSSIBLE SUNSHINE........... 13 HR 39 MIN 49 SEC (819 MIN 49 SEC)  
ALTITUDE OF SUN AT 13:11:55 MDT... 64.64 DEGREES  
 
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 04/26/2017 AT 0600 MDT  
 
FREEZING LEVEL.................. 7965 FT MSL (3126 FT AGL)  
CONVECTIVE CONDENSATION LEVEL... 10133 FT MSL (5294 FT AGL)  
LIFTED CONDENSATION LEVEL....... 12096 FT MSL (7257 FT AGL)  
LIFTED INDEX.................... +0.5  
K INDEX......................... +14.9  
 
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 -57.3 -71.1 295 41 21 -8.6 -4.7 107.0 224.6 51.9 M M  
45000 -56.3 -69.3 315 37 19 8.6 4.7 83.7 182.7 41.4 M M  
40000 -54.4 -65.9 320 58 30 2.0 1.1 63.4 146.1 31.1 M M  
38000 -54.7 -66.5 320 72 37 -1.1 -0.6 54.1 129.4 25.7 M M  
36000 -54.4 -65.9 325 89 46 2.8 1.5 44.8 112.6 20.1 M M  
34000 -51.6 -60.9 330 100 52 6.7 3.7 40.6 105.0 17.7 M M  
32000 -47.4 -53.3 325 84 43 6.9 3.8 37.9 100.3 16.2 M M  
30000 -44.0 -47.2 320 68 35 4.2 2.3 34.8 94.7 14.3 M M  
29000 -42.6 -44.7 320 61 31 4.6 2.5 32.6 90.7 12.9 M M  
28000 -41.3 -42.3 315 53 27 4.6 2.5 30.6 87.1 11.5 M M  
27000 -40.2 -40.4 315 46 24 2.6 1.4 28.2 82.8 9.8 M M  
26000 -38.3 -36.9 310 39 20 8.1 4.5 26.9 80.5 8.9 M M  
25000 -35.9 -32.6 305 32 17 8.0 4.4 26.3 79.4 8.5 M M  
24000 -33.5 -28.3 310 35 18 8.0 4.4 25.6 78.2 8.1 M M  
23000 -31.0 -23.8 315 37 19 8.7 4.8 25.1 77.3 7.7 M M  
22000 -28.8 -19.8 310 38 19 6.3 3.5 24.3 75.7 7.1 M M  
21000 -27.1 -16.8 305 36 18 6.8 3.7 22.8 73.0 5.9 M M  
20000 -25.4 -13.7 295 34 18 5.7 3.1 21.2 70.1 4.7 M M  
19500 -24.0 -11.2 295 30 16 7.2 4.0 20.2 68.4 4.0 M M  
19000 -23.0 -9.4 300 27 14 7.2 4.0 19.7 67.5 3.6 M M  
18500 -21.9 -7.4 300 25 13 7.6 4.1 19.3 66.8 3.2 M M  
18000 -20.6 -5.1 300 23 12 8.6 4.7 19.1 66.3 3.0 M M  
17500 -19.4 -2.9 300 23 12 8.3 4.6 18.9 65.9 2.9 M M  
17000 -18.2 -0.8 300 22 11 7.5 4.1 18.5 65.3 2.5 M M  
16500 -17.1 1.2 300 22 11 7.6 4.2 18.1 64.6 2.2 M M  
16000 -16.0 3.2 300 21 11 7.9 4.3 17.8 64.0 1.9 M M  
15500 -15.2 4.6 300 19 10 -1.2 -0.7 17.0 62.7 1.2 M M  
15000 -14.8 5.4 300 18 9 10.2 5.6 15.9 60.7 0.1 M M  
14500 -13.9 7.0 305 16 8 1.6 0.9 15.4 59.6 -0.4 784 4.0  
14000 -13.5 7.7 305 15 8 5.8 3.2 14.2 57.6 -1.5 757 3.8  
13500 -12.7 9.1 315 13 7 5.2 2.9 13.5 56.2 -2.2 719 3.7  
13000 -12.0 10.4 330 12 6 5.3 2.9 12.7 54.9 -2.9 682 3.5  
12500 -10.9 12.4 340 12 6 9.0 4.9 12.3 54.2 -3.3 635 3.2  
12000 -9.6 14.7 355 12 6 8.8 4.8 12.2 53.9 -3.5 581 3.0  
11500 -8.4 16.9 355 13 7 7.4 4.0 11.9 53.4 -3.8 530 2.7  
11000 -7.3 18.9 355 13 7 7.5 4.1 11.5 52.7 -4.2 483 2.5  
10500 -6.2 20.8 355 14 7 8.8 4.8 11.2 52.1 -4.6 435 2.2  
10250 -5.5 22.1 355 14 7 10.9 6.0 11.2 52.2 -4.6 405 2.1  
10000 -4.7 23.5 355 15 8 7.9 4.3 11.2 52.2 -4.6 375 1.9  
9750 -4.3 24.3 355 14 7 4.2 2.3 10.9 51.6 -4.9 356 1.8  
9500 -4.0 24.8 355 13 7 6.3 3.5 10.5 50.9 -5.3 339 1.7  
9250 -3.4 25.9 360 12 6 8.9 4.9 10.4 50.7 -5.5 314 1.6  
9000 -2.7 27.1 360 10 5 9.0 5.0 10.3 50.6 -5.5 286 1.5  
8750 -2.1 28.2 360 9 4 9.0 4.9 10.3 50.5 -5.6 259 1.3  
8500 -1.4 29.5 005 7 4 9.2 5.0 10.2 50.4 -5.7 231 1.2  
8250 -0.7 30.7 010 6 3 8.4 4.6 10.1 50.3 -5.8 204 1.0  
8000 -0.2 31.6 020 4 2 7.1 3.9 10.0 50.0 -6.0 180 0.9  
7750 0.3 32.5 035 4 2 6.9 3.8 9.8 49.6 -6.2 157 0.8  
7500 0.9 33.6 050 4 2 7.0 3.8 9.6 49.2 -6.4 135 0.7  
7250 1.4 34.5 065 5 3 6.9 3.8 9.3 48.8 -6.7 112 0.6  
7000 1.9 35.4 075 6 3 7.3 4.0 9.1 48.4 -6.9 89 0.5  
6750 2.4 36.3 075 5 2 5.7 3.1 8.9 48.1 -7.2 67 0.3  
6500 2.7 36.9 070 3 2 3.9 2.1 8.5 47.3 -7.6 50 0.3  
6250 3.0 37.4 055 2 1 4.3 2.3 8.1 46.5 -8.1 34 0.2  
6000 3.3 37.9 335 1 0 4.2 2.3 7.7 45.8 -8.5 18 0.1  
5750 3.5 38.3 350 1 0 4.3 2.3 7.2 45.0 -9.0 2 0.0  
5500 3.8 38.8 025 1 1 4.0 2.2 6.8 44.3 -9.5 M M  
5250 4.1 39.4 040 2 1 4.9 2.7 6.4 43.5 -9.9 M M  
5000 4.4 39.9 045 3 2 -0.1 -0.1 6.0 42.7 -10.4 M M  
 
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *  
 
04/26/2017 AT 0900 MDT | 04/26/2017 AT 1200 MDT  
|  
K INDEX... +13.1 LI... +1.5 | K INDEX... +14.9 LI... +1.6  
CAPE... +19.6 CIN... -6.6 | CAPE... +57.3 CIN... -2.9  
|  
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 -57.3 -71.1 310 37 19 0.9 0.5 | -57.3 -71.1 315 35 18 1.6 0.9  
45000 -55.9 -68.6 315 55 28 1.0 0.6 | -54.9 -66.8 320 53 27 1.8 1.0  
40000 -56.3 -69.3 315 68 35 -0.3 -0.2 | -55.3 -67.5 310 67 34 -0.4 -0.2  
38000 -55.7 -68.3 320 73 38 3.0 1.6 | -55.0 -67.0 310 72 37 1.7 0.9  
36000 -54.0 -65.2 325 81 42 2.9 1.6 | -54.0 -65.2 315 78 40 1.7 0.9  
34000 -52.1 -61.8 330 88 46 5.3 2.9 | -52.9 -63.2 320 84 43 4.7 2.6  
32000 -48.2 -54.8 330 84 43 6.6 3.6 | -49.1 -56.4 315 84 43 6.3 3.5  
30000 -44.3 -47.7 325 79 41 7.6 4.2 | -45.3 -49.5 315 84 43 8.1 4.5  
29000 -41.9 -43.4 325 77 40 7.9 4.3 | -42.7 -44.9 315 83 43 8.6 4.7  
28000 -39.5 -39.1 325 76 39 7.9 4.3 | -39.5 -39.1 315 82 42 8.6 4.7  
27000 -37.2 -35.0 325 74 38 7.9 4.3 | -36.9 -34.4 320 81 42 8.6 4.7  
26000 -34.6 -30.3 320 69 36 6.1 3.3 | -34.4 -29.9 320 79 41 8.1 4.5  
25000 -32.8 -27.0 320 64 33 6.1 3.3 | -32.0 -25.6 325 78 40 8.1 4.5  
24000 -31.0 -23.8 320 58 30 6.2 3.4 | -29.6 -21.3 330 76 39 8.3 4.6  
23000 -29.4 -20.9 315 52 27 5.0 2.8 | -27.6 -17.7 330 69 36 6.1 3.3  
22000 -27.9 -18.2 315 46 24 5.0 2.8 | -25.8 -14.4 330 60 31 6.1 3.3  
21000 -26.4 -15.5 315 40 21 5.1 2.8 | -23.9 -11.0 325 51 26 5.8 3.2  
20000 -24.7 -12.5 310 36 19 6.0 3.3 | -22.6 -8.7 320 44 23 4.3 2.4  
19500 -23.8 -10.8 310 35 18 6.1 3.3 | -21.9 -7.4 320 41 21 4.4 2.4  
19000 -22.9 -9.2 310 34 17 6.1 3.3 | -21.3 -6.3 315 38 20 4.4 2.4  
18500 -22.0 -7.6 305 32 17 6.1 3.3 | -20.6 -5.1 315 35 18 4.3 2.4  
18000 -21.0 -5.8 305 31 16 7.5 4.1 | -19.9 -3.8 310 33 17 5.4 2.9  
17500 -19.9 -3.8 300 31 16 7.4 4.1 | -19.2 -2.6 305 31 16 5.3 2.9  
17000 -18.8 -1.8 300 31 16 6.1 3.3 | -18.4 -1.1 305 29 15 5.1 2.8  
16500 -18.0 -0.4 300 30 16 5.5 3.0 | -17.7 0.1 300 28 14 5.0 2.8  
16000 -17.1 1.2 300 29 15 5.5 3.0 | -17.0 1.4 300 26 14 5.5 3.0  
15500 -16.3 2.7 300 28 14 5.6 3.1 | -16.0 3.2 295 26 13 6.9 3.8  
15000 -15.5 4.1 300 26 14 5.7 3.1 | -15.0 5.0 290 25 13 6.9 3.8  
14500 -14.7 5.5 300 24 13 5.5 3.0 | -14.1 6.6 285 24 12 4.7 2.6  
14000 -13.9 7.0 300 22 11 5.5 3.0 | -13.4 7.9 285 23 12 4.8 2.6  
13500 -13.0 8.6 300 20 10 7.1 3.9 | -12.1 10.2 280 20 10 6.7 3.7  
13000 -11.5 11.3 295 16 8 7.4 4.1 | -11.1 12.0 275 18 9 7.0 3.9  
12500 -10.3 13.5 295 14 7 8.4 4.6 | -10.0 14.0 270 17 9 7.9 4.3  
12000 -9.1 15.6 295 12 6 8.3 4.6 | -8.9 16.0 270 17 9 7.9 4.4  
11500 -7.9 17.8 300 10 5 8.1 4.5 | -7.7 18.1 265 17 9 8.2 4.5  
11000 -6.7 19.9 305 8 4 7.6 4.2 | -6.5 20.3 265 16 8 8.1 4.4  
10500 -5.8 21.6 310 6 3 6.1 3.4 | -5.3 22.5 265 15 8 7.3 4.0  
10250 -5.3 22.5 310 5 2 7.3 4.0 | -4.8 23.4 265 15 8 9.3 5.1  
10000 -4.7 23.5 310 4 2 8.2 4.5 | -4.0 24.8 265 14 7 9.8 5.4  
9750 -4.2 24.4 305 3 2 7.4 4.0 | -3.4 25.9 265 14 7 7.7 4.2  
9500 -3.6 25.5 295 3 2 7.4 4.1 | -2.9 26.8 265 13 7 7.6 4.2  
9250 -3.1 26.4 280 3 1 6.8 3.7 | -2.3 27.9 265 12 6 7.7 4.2  
9000 -2.7 27.1 265 2 1 6.2 3.4 | -1.7 28.9 265 11 6 7.3 4.0  
8750 -2.2 28.0 255 2 1 6.9 3.8 | -1.2 29.8 265 10 5 7.0 3.8  
8500 -1.7 28.9 245 2 1 7.2 3.9 | -0.7 30.7 270 9 5 6.9 3.8  
8250 -1.2 29.8 235 2 1 7.3 4.0 | -0.2 31.6 270 9 4 7.8 4.3  
8000 -0.6 30.9 225 2 1 6.9 3.8 | 0.4 32.7 270 8 4 9.5 5.2  
7750 -0.2 31.6 220 2 1 5.9 3.3 | 1.1 34.0 270 8 4 9.6 5.3  
7500 0.2 32.4 215 2 1 5.6 3.1 | 1.8 35.2 270 8 4 9.2 5.0  
7250 0.7 33.3 210 2 1 6.2 3.4 | 2.5 36.5 270 8 4 10.0 5.5  
7000 1.2 34.2 205 2 1 6.7 3.7 | 3.3 37.9 275 8 4 10.7 5.9  
6750 1.6 34.9 205 2 1 5.8 3.2 | 4.1 39.4 275 8 4 10.0 5.5  
6500 2.1 35.8 200 2 1 7.5 4.1 | 4.8 40.6 275 8 4 10.5 5.8  
6250 2.8 37.0 205 2 1 10.8 5.9 | 5.6 42.1 275 8 4 11.9 6.5  
6000 3.6 38.5 205 2 1 11.0 6.0 | 6.5 43.7 275 8 4 12.0 6.6  
5750 4.4 39.9 205 2 1 9.8 5.4 | 7.4 45.3 275 7 4 11.6 6.4  
5500 5.1 41.2 210 2 1 9.9 5.5 | 8.4 47.1 275 7 4 15.0 8.2  
5250 5.9 42.6 210 2 1 11.4 6.3 | 9.7 49.5 275 7 4 20.5 11.2  
5000 M M M M M M M | M M M M M M M  
 
04/26/2017 AT 1500 MDT | 04/26/2017 AT 1800 MDT  
|  
K INDEX... +13.3 LI... +3.6 | K INDEX... +19.6 LI... +2.8  
CAPE... 0.0 CIN... -0.1 | 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 -57.4 -71.3 310 38 20 2.3 1.3 | -57.2 -71.0 305 43 22 2.4 1.3  
45000 -53.9 -65.0 320 51 26 2.7 1.5 | -53.6 -64.5 310 55 28 2.6 1.4  
40000 -55.7 -68.3 310 72 37 -1.3 -0.7 | -53.3 -63.9 300 69 36 0.1 0.0  
38000 -55.6 -68.1 305 81 42 2.3 1.3 | -53.6 -64.5 300 72 37 -1.2 -0.7  
36000 -54.2 -65.6 310 89 46 2.3 1.3 | -54.3 -65.7 295 70 36 -1.2 -0.7  
34000 -52.7 -62.9 310 96 49 5.2 2.8 | -55.0 -67.0 295 68 35 2.4 1.3  
32000 -48.9 -56.0 310 83 43 6.4 3.5 | -51.1 -60.0 290 61 32 6.6 3.6  
30000 -45.1 -49.2 305 70 36 7.6 4.2 | -47.1 -52.8 290 55 28 8.3 4.6  
29000 -42.1 -43.8 305 66 34 7.9 4.3 | -43.7 -46.7 290 52 27 9.1 5.0  
28000 -39.8 -39.6 305 63 33 7.9 4.3 | -41.0 -41.8 285 50 26 9.1 5.0  
27000 -37.4 -35.3 305 61 31 7.9 4.4 | -38.3 -36.9 285 48 25 9.1 5.0  
26000 -34.9 -30.8 305 60 31 8.4 4.6 | -35.7 -32.3 285 45 23 8.5 4.6  
25000 -32.4 -26.3 305 60 31 8.4 4.6 | -33.2 -27.8 285 42 21 8.5 4.6  
24000 -29.9 -21.8 305 59 31 8.6 4.7 | -30.7 -23.3 285 38 20 8.6 4.7  
23000 -27.8 -18.0 310 53 28 6.8 3.8 | -28.3 -18.9 285 37 19 7.8 4.3  
22000 -25.7 -14.3 315 46 24 6.8 3.8 | -26.0 -14.8 285 35 18 7.8 4.3  
21000 -23.7 -10.7 325 40 20 6.9 3.8 | -23.7 -10.7 285 34 18 7.6 4.2  
20000 -21.5 -6.7 320 38 19 7.2 4.0 | -21.6 -6.9 285 33 17 6.9 3.8  
19500 -20.5 -4.9 315 38 19 7.2 4.0 | -20.6 -5.1 285 32 17 6.9 3.8  
19000 -19.4 -2.9 310 37 19 7.2 4.0 | -19.6 -3.3 285 32 16 6.9 3.8  
18500 -18.3 -0.9 305 38 19 7.3 4.0 | -18.6 -1.5 285 31 16 7.0 3.8  
18000 -17.3 0.9 305 38 19 6.1 3.3 | -17.6 0.3 285 31 16 5.8 3.2  
17500 -16.4 2.5 305 38 19 6.2 3.4 | -16.8 1.8 290 31 16 5.9 3.2  
17000 -15.5 4.1 305 37 19 4.2 2.3 | -15.9 3.4 290 30 16 5.8 3.2  
16500 -15.1 4.8 305 35 18 3.4 1.8 | -15.1 4.8 290 29 15 5.7 3.1  
16000 -14.6 5.7 305 34 17 3.5 1.9 | -14.2 6.4 290 28 15 5.6 3.1  
15500 -14.0 6.8 305 31 16 4.4 2.4 | -13.4 7.9 290 27 14 5.1 2.8  
15000 -13.4 7.9 300 29 15 4.2 2.3 | -12.7 9.1 285 25 13 5.0 2.7  
14500 -12.6 9.3 300 27 14 6.6 3.6 | -11.8 10.8 285 24 12 7.3 4.0  
14000 -11.7 10.9 295 25 13 6.4 3.5 | -10.2 13.6 275 22 11 7.1 3.9  
13500 -10.1 13.8 290 22 12 7.3 4.0 | -9.2 15.4 270 21 11 7.1 3.9  
13000 -9.1 15.6 285 21 11 7.3 4.0 | -8.2 17.2 265 20 10 7.0 3.8  
12500 -8.0 17.6 280 20 10 7.4 4.1 | -7.2 19.0 265 20 10 6.3 3.4  
12000 -6.9 19.6 270 19 10 7.5 4.1 | -6.3 20.7 260 21 11 6.2 3.4  
11500 -5.7 21.7 265 18 9 8.2 4.5 | -5.5 22.1 260 20 10 5.5 3.0  
11000 -4.5 23.9 260 17 9 8.1 4.4 | -4.7 23.5 260 20 10 5.4 3.0  
10500 -3.3 26.1 255 16 8 7.8 4.3 | -3.9 25.0 260 19 10 4.3 2.4  
10250 -2.8 27.0 255 15 8 8.5 4.7 | -3.6 25.5 265 18 9 5.3 2.9  
10000 -2.1 28.2 255 14 7 9.2 5.0 | -3.1 26.4 265 18 9 7.9 4.3  
9750 -1.4 29.5 255 13 7 8.6 4.7 | -2.4 27.7 270 18 9 9.7 5.3  
9500 -0.8 30.6 255 12 6 8.6 4.7 | -1.7 28.9 270 18 9 10.1 5.5  
9250 -0.2 31.6 255 11 6 8.2 4.5 | -0.9 30.4 270 18 9 9.6 5.3  
9000 0.4 32.7 255 10 5 8.8 4.8 | -0.2 31.6 270 18 9 9.2 5.1  
8750 1.1 34.0 255 10 5 10.0 5.5 | 0.5 32.9 270 18 9 10.0 5.5  
8500 1.8 35.2 255 10 5 9.5 5.2 | 1.2 34.2 270 18 9 10.0 5.5  
8250 2.6 36.7 255 10 5 10.7 5.9 | 2.0 35.6 270 18 9 11.0 6.0  
8000 3.4 38.1 255 10 5 11.5 6.3 | 2.9 37.2 270 18 9 11.7 6.4  
7750 4.2 39.6 255 9 5 9.9 5.4 | 3.7 38.7 270 18 9 9.8 5.4  
7500 4.9 40.8 255 9 5 9.3 5.1 | 4.4 39.9 270 18 9 8.8 4.8  
7250 5.6 42.1 255 9 5 9.4 5.2 | 5.0 41.0 270 18 9 9.6 5.3  
7000 6.3 43.3 255 9 5 9.6 5.3 | 5.8 42.4 270 18 9 10.2 5.6  
6750 7.1 44.8 255 9 5 10.1 5.6 | 6.6 43.9 270 18 9 9.9 5.4  
6500 7.8 46.0 255 9 5 10.4 5.7 | 7.3 45.1 270 17 9 9.8 5.4  
6250 8.6 47.5 255 9 4 11.0 6.0 | 8.0 46.4 270 17 9 10.5 5.7  
6000 9.5 49.1 260 8 4 11.8 6.5 | 8.9 48.0 270 17 9 10.9 6.0  
5750 10.4 50.7 260 8 4 10.8 5.9 | 9.7 49.5 270 16 8 11.5 6.3  
5500 11.2 52.2 260 8 4 14.4 7.9 | 10.5 50.9 270 14 7 10.1 5.5  
5250 12.6 54.7 260 8 4 23.2 12.7 | 11.1 52.0 275 14 7 5.6 3.1  
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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