849  
UXUS97 KGJT 201334  
SRGGJT  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO  
0634 MST THURSDAY, FEBRUARY 20, 2020  
 
THIS FORECAST IS FOR THURSDAY, FEBRUARY 20, 2020:  
 
IF THE TRIGGER TEMPERATURE OF 36.2 F/2.4 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... FAIR  
MAXIMUM RATE OF LIFT........................ 353 FT/MIN (1.8 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 10208 FT MSL (5369 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 41.0 F/5.5 C  
TIME OF TRIGGER TEMPERATURE.................... 1130 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................. 8697 FT MSL (3857 FT AGL)  
THERMAL SOARING OUTLOOK FOR FRIDAY 02/21....... FAIR  
 
WAVE SOARING INDEX............................. NOT AVAILABLE  
 
REMARKS...  
 
***ATTENTION SOARING FORECAST USERS***THE NATIONAL WEATHER SERVICE IN BOULDER WANTS TO HEAR FROM YOU.  
PLEASE SEND AND EMAIL TO PAUL.T.SCHLATTER@NOAA.GOV AND LET US KNOW HOW YOU USE THE SOARING FORECAST. THANKS!  
 
SUNRISE/SUNSET.................... 06:59:31 / 17:56:15 MST  
TOTAL POSSIBLE SUNSHINE........... 10 HR 56 MIN 44 SEC (656 MIN 44 SEC)  
ALTITUDE OF SUN AT 12:27:53 MST... 39.56 DEGREES  
 
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 02/20/2020 AT 0500 MST  
 
FREEZING LEVEL.................. ENTIRE AIRMASS BELOW 32 F / 0 C  
CONVECTIVE CONDENSATION LEVEL... 20954 FT MSL (16115 FT AGL)  
LIFTED CONDENSATION LEVEL....... 15541 FT MSL (10701 FT AGL)  
LIFTED INDEX.................... +12.9  
K INDEX......................... -50.2  
 
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 -61.0 -77.8 270 76 39 5.2 2.9 100.9 213.7 54.4 M M  
45000 -55.3 -67.5 270 96 49 4.0 2.2 85.8 186.4 49.0 M M  
40000 -50.2 -58.4 275 121 62 3.7 2.0 69.5 157.0 42.0 M M  
38000 -47.5 -53.5 275 114 59 4.5 2.4 64.6 148.2 39.8 M M  
36000 -44.9 -48.8 280 109 56 1.8 1.0 59.9 139.9 37.6 M M  
34000 -47.4 -53.3 280 106 54 4.8 2.6 47.9 118.3 30.2 M M  
32000 -47.4 -53.3 285 94 48 8.2 4.5 39.7 103.4 25.0 M M  
30000 -44.0 -47.2 290 81 42 5.2 2.9 35.4 95.8 22.6 M M  
29000 -42.4 -44.3 290 73 38 5.3 2.9 33.5 92.3 21.5 M M  
28000 -40.8 -41.4 295 65 34 5.3 2.9 31.8 89.2 20.4 M M  
27000 -39.4 -38.9 295 57 29 -0.8 -0.4 30.0 86.0 19.3 M M  
26000 -39.2 -38.6 300 50 26 5.6 3.1 26.5 79.7 16.8 M M  
25000 -37.2 -35.0 290 45 23 6.6 3.6 25.4 77.7 16.1 M M  
24000 -35.2 -31.4 295 38 20 6.8 3.7 24.2 75.5 15.3 M M  
23000 -33.4 -28.1 290 34 18 5.4 3.0 22.7 72.9 14.3 M M  
22000 -31.5 -24.7 285 31 16 6.9 3.8 21.6 70.9 13.6 M M  
21000 -29.4 -20.9 295 28 15 6.9 3.8 20.5 69.0 12.9 M M  
20000 -27.3 -17.1 305 26 13 6.9 3.8 19.6 67.2 12.2 M M  
19500 -26.3 -15.3 310 25 13 6.9 3.8 19.0 66.3 11.9 M M  
19000 -25.2 -13.4 315 24 12 6.9 3.8 18.5 65.3 11.5 M M  
18500 -24.2 -11.6 320 23 12 7.1 3.9 18.0 64.5 11.1 M M  
18000 -23.1 -9.6 320 22 11 7.2 4.0 17.6 63.6 10.8 M M  
17500 -22.0 -7.6 320 22 11 7.2 4.0 17.1 62.8 10.5 M M  
17000 -21.0 -5.8 315 21 11 7.0 3.9 16.7 62.1 10.2 M M  
16500 -19.7 -3.5 315 20 10 9.5 5.2 16.4 61.6 10.0 M M  
16000 -17.6 0.3 315 19 10 9.7 5.3 16.4 61.5 10.0 M M  
15500 -16.3 2.7 330 19 10 7.1 3.9 16.2 61.1 9.9 M M  
15000 -15.3 4.5 340 19 10 7.0 3.8 15.7 60.3 9.6 M M  
14500 -14.2 6.4 350 20 10 7.0 3.8 15.3 59.5 9.2 M M  
14000 -13.2 8.2 355 21 11 7.0 3.8 14.8 58.7 8.9 M M  
13500 -12.1 10.2 005 19 10 7.0 3.8 14.3 57.8 8.5 M M  
13000 -11.1 12.0 010 18 9 6.8 3.7 13.9 57.0 8.1 M M  
12500 -10.0 14.0 020 16 8 4.3 2.3 13.4 56.2 7.8 M M  
12000 -10.1 13.8 030 16 8 -1.4 -0.7 11.8 53.3 6.3 M M  
11500 -10.3 13.5 035 14 7 -1.3 -0.7 10.0 50.0 4.7 M M  
11000 -10.5 13.1 040 13 7 -1.4 -0.8 8.2 46.8 3.0 M M  
10500 -10.6 12.9 050 12 6 -2.6 -1.5 6.5 43.7 1.4 M M  
10250 -11.1 12.0 055 11 6 -11.3 -6.2 5.2 41.4 0.2 M M  
10000 -11.9 10.6 060 10 5 -1.4 -0.8 3.7 38.6 -1.3 368 1.9  
9750 -11.3 11.7 060 9 5 10.7 5.8 3.5 38.3 -1.5 342 1.7  
9500 -10.7 12.7 065 8 4 7.0 3.8 3.4 38.1 -1.6 317 1.6  
9250 -10.1 13.8 075 8 4 9.7 5.3 3.2 37.8 -1.7 291 1.5  
9000 -9.5 14.9 080 7 4 2.4 1.3 3.1 37.6 -1.8 265 1.3  
8750 -9.8 14.4 085 6 3 -2.5 -1.4 2.2 35.9 -2.8 265 1.3  
8500 -9.6 14.7 090 5 3 6.1 3.3 1.6 34.8 -3.5 255 1.3  
8250 -9.1 15.6 100 4 2 7.6 4.2 1.4 34.5 -3.6 230 1.2  
8000 -8.7 16.3 115 3 2 2.0 1.1 1.0 33.9 -4.0 211 1.1  
7750 -8.7 16.3 095 3 2 -0.9 -0.5 0.3 32.5 -4.7 204 1.0  
7500 -8.7 16.3 075 4 2 1.3 0.7 -0.5 31.1 -5.5 197 1.0  
7250 -8.5 16.7 065 5 2 4.8 2.6 -1.0 30.2 -6.0 182 0.9  
7000 -8.0 17.6 055 6 3 6.0 3.3 -1.3 29.7 -6.3 162 0.8  
6750 -7.6 18.3 055 6 3 5.6 3.1 -1.6 29.1 -6.6 142 0.7  
6500 -7.2 19.0 050 7 4 5.7 3.1 -1.9 28.5 -6.9 121 0.6  
6250 -6.7 19.9 050 7 4 5.7 3.1 -2.2 28.0 -7.2 101 0.5  
6000 -6.3 20.7 050 8 4 5.7 3.1 -2.5 27.5 -7.5 81 0.4  
5750 -5.9 21.4 045 7 3 5.7 3.2 -2.8 26.9 -7.9 61 0.3  
5500 -5.5 22.1 040 5 3 5.6 3.1 -3.1 26.3 -8.2 40 0.2  
5250 -5.0 23.0 025 3 2 6.1 3.4 -3.4 25.8 -8.5 20 0.1  
5000 -4.7 23.5 020 2 1 -0.9 -0.5 -3.9 25.0 -9.0 4 0.0  
 
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *  
 
02/20/2020 AT 0800 MST | 02/20/2020 AT 1100 MST  
|  
CAPE... 0.0 LI... +8.1 | CAPE... 0.0 LI... +7.5  
CINH... -1.5 K INDEX... -42.8 | CINH... -0.2 K INDEX... -44.2  
|  
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 -60.7 -77.3 270 43 22 2.2 1.2 | -60.4 -76.7 270 43 22 2.1 1.1  
45000 -57.3 -71.1 275 55 28 4.0 2.2 | -56.9 -70.4 270 58 30 4.3 2.4  
40000 -50.3 -58.5 270 61 31 4.5 2.5 | -50.8 -59.4 265 62 32 4.1 2.3  
38000 -49.3 -56.7 270 59 30 -0.5 -0.3 | -49.9 -57.8 265 58 30 -0.6 -0.3  
36000 -49.6 -57.3 275 53 27 -0.5 -0.3 | -50.2 -58.4 265 51 26 -0.6 -0.3  
34000 -49.5 -57.1 275 48 25 4.1 2.2 | -49.9 -57.8 270 43 22 3.8 2.1  
32000 -47.3 -53.1 280 44 23 3.7 2.0 | -47.6 -53.7 275 38 20 4.0 2.2  
30000 -44.6 -48.3 290 40 21 8.6 4.7 | -44.5 -48.1 280 33 17 8.4 4.6  
29000 -42.1 -43.8 290 39 20 8.3 4.5 | -42.0 -43.6 280 32 16 8.5 4.7  
28000 -39.7 -39.5 290 38 20 8.3 4.5 | -39.4 -38.9 285 31 16 8.5 4.7  
27000 -37.2 -35.0 290 37 19 8.0 4.4 | -36.9 -34.4 290 29 15 8.2 4.5  
26000 -35.3 -31.5 295 34 18 6.1 3.3 | -34.5 -30.1 290 28 15 8.0 4.4  
25000 -33.4 -28.1 295 31 16 6.1 3.3 | -32.1 -25.8 290 27 14 8.0 4.4  
24000 -31.1 -24.0 295 26 13 5.5 3.0 | -29.7 -21.5 290 26 13 7.1 3.9  
23000 -29.7 -21.5 295 22 12 4.7 2.6 | -28.3 -18.9 290 22 12 4.1 2.2  
22000 -28.3 -18.9 300 19 10 4.7 2.6 | -27.1 -16.8 295 18 9 4.1 2.3  
21000 -26.9 -16.4 300 15 8 5.8 3.2 | -25.5 -13.9 295 14 7 5.2 2.8  
20000 -25.1 -13.2 305 13 7 5.9 3.2 | -23.9 -11.0 300 12 6 5.1 2.8  
19500 -24.2 -11.6 305 12 6 5.9 3.2 | -23.2 -9.8 300 11 6 5.1 2.8  
19000 -23.3 -9.9 305 12 6 5.9 3.2 | -22.4 -8.3 300 10 5 5.0 2.7  
18500 -22.4 -8.3 310 11 6 6.1 3.3 | -21.6 -6.9 300 10 5 6.2 3.4  
18000 -21.5 -6.7 310 10 5 6.1 3.4 | -20.7 -5.3 300 9 5 6.1 3.3  
17500 -20.6 -5.1 315 9 5 6.2 3.4 | -19.8 -3.6 300 8 4 6.2 3.4  
17000 -19.7 -3.5 320 8 4 6.4 3.5 | -18.8 -1.8 300 8 4 6.2 3.4  
16500 -18.7 -1.7 325 8 4 6.4 3.5 | -17.9 -0.2 300 7 3 6.3 3.5  
16000 -17.7 0.1 330 7 4 6.5 3.6 | -16.9 1.6 305 6 3 6.8 3.7  
15500 -16.8 1.8 335 7 4 6.4 3.5 | -15.9 3.4 305 5 2 6.8 3.7  
15000 -15.8 3.6 340 7 3 6.8 3.7 | -14.9 5.2 310 4 2 6.5 3.6  
14500 -14.7 5.5 350 6 3 6.8 3.7 | -13.9 7.0 320 3 2 6.5 3.6  
14000 -13.7 7.3 355 6 3 7.0 3.9 | -13.0 8.6 330 2 1 6.9 3.8  
13500 -12.6 9.3 360 5 3 7.1 3.9 | -11.9 10.6 345 2 1 6.9 3.8  
13000 -11.6 11.1 010 5 3 6.8 3.7 | -10.9 12.4 005 2 1 6.8 3.8  
12500 -10.6 12.9 020 4 2 6.6 3.6 | -9.9 14.2 025 2 1 6.9 3.8  
12000 -9.6 14.7 030 4 2 5.3 2.9 | -8.9 16.0 050 2 1 6.4 3.5  
11500 -8.9 16.0 045 4 2 4.8 2.6 | -7.9 17.8 070 2 1 6.6 3.6  
11000 -8.4 16.9 055 3 2 1.7 0.9 | -7.0 19.4 090 2 1 4.6 2.5  
10500 -8.3 17.1 070 3 2 0.9 0.5 | -6.4 20.5 105 2 1 4.9 2.7  
10250 -8.2 17.2 075 3 2 0.1 0.0 | -6.1 21.0 110 2 1 2.6 1.4  
10000 -8.3 17.1 080 3 2 -1.2 -0.7 | -6.0 21.2 115 2 1 -0.1 -0.0  
9750 -8.4 16.9 085 3 2 -1.5 -0.8 | -6.0 21.2 120 2 1 0.3 0.2  
9500 -8.5 16.7 090 3 2 -2.0 -1.1 | -6.0 21.2 125 2 1 0.3 0.1  
9250 -8.6 16.5 095 3 2 0.2 0.1 | -6.0 21.2 125 2 1 0.1 0.1  
9000 -8.5 16.7 095 3 2 2.7 1.5 | -6.0 21.2 125 2 1 1.0 0.5  
8750 -8.4 16.9 100 3 1 0.6 0.3 | -6.0 21.2 125 2 1 -2.3 -1.3  
8500 -8.4 16.9 100 3 2 -0.2 -0.1 | -6.3 20.7 125 3 1 -2.6 -1.4  
8250 -8.4 16.9 100 3 2 1.9 1.0 | -6.3 20.7 120 3 1 1.8 1.0  
8000 -8.2 17.2 100 3 2 3.2 1.8 | -6.1 21.0 115 2 1 3.0 1.7  
7750 -8.0 17.6 100 3 1 1.1 0.6 | -6.1 21.0 105 2 1 0.7 0.4  
7500 -8.0 17.6 090 3 1 1.2 0.6 | -5.8 21.6 095 2 1 5.0 2.7  
7250 -7.8 18.0 090 3 1 3.2 1.8 | -5.5 22.1 085 2 1 3.2 1.8  
7000 -7.4 18.7 080 3 1 4.2 2.3 | -5.2 22.6 075 2 1 6.0 3.3  
6750 -7.0 19.4 080 2 1 3.9 2.1 | -4.6 23.7 075 2 1 9.0 4.9  
6500 -6.8 19.8 075 2 1 1.7 1.0 | -3.9 25.0 070 1 1 9.0 4.9  
6250 -6.7 19.9 070 2 1 2.4 1.3 | -3.3 26.1 065 1 1 8.2 4.5  
6000 -6.5 20.3 065 3 1 1.7 0.9 | -2.6 27.3 065 1 1 11.9 6.5  
5750 -6.4 20.5 065 2 1 0.9 0.5 | -1.4 29.5 065 1 1 20.6 11.3  
5500 -6.3 20.7 060 2 1 1.7 0.9 | -0.1 31.8 065 1 1 6.4 3.5  
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  
 
02/20/2020 AT 1400 MST | 02/20/2020 AT 1700 MST  
|  
CAPE... 0.0 LI... +7.9 | CAPE... 0.0 LI... +9.0  
CINH... -1.7 K INDEX... -43.4 | CINH... -1.7 K INDEX... -43.8  
|  
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 -60.7 -77.3 270 44 23 2.1 1.1 | -61.0 -77.8 270 44 22 1.9 1.1  
45000 -57.4 -71.3 265 59 30 4.5 2.5 | -57.8 -72.0 265 58 30 4.4 2.4  
40000 -50.9 -59.6 265 64 33 4.4 2.4 | -51.5 -60.7 260 63 33 4.3 2.3  
38000 -49.8 -57.6 265 59 30 -0.0 -0.0 | -50.1 -58.2 260 59 30 1.2 0.7  
36000 -49.9 -57.8 265 48 25 -0.0 -0.0 | -49.3 -56.7 265 50 26 1.2 0.7  
34000 -49.3 -56.7 270 40 21 3.5 1.9 | -48.3 -54.9 265 42 22 2.7 1.5  
32000 -47.1 -52.8 270 34 18 3.6 2.0 | -46.6 -51.9 265 34 18 2.8 1.5  
30000 -44.2 -47.6 270 29 15 7.9 4.3 | -44.2 -47.6 270 27 14 7.2 4.0  
29000 -41.8 -43.2 275 27 14 8.0 4.4 | -42.0 -43.6 275 25 13 7.3 4.0  
28000 -39.5 -39.1 280 26 13 8.0 4.4 | -39.8 -39.6 275 23 12 7.3 4.0  
27000 -37.1 -34.8 285 24 12 8.3 4.5 | -37.5 -35.5 280 21 11 8.3 4.5  
26000 -34.5 -30.1 285 24 12 8.4 4.6 | -35.0 -31.0 285 21 11 8.6 4.7  
25000 -32.0 -25.6 285 23 12 8.4 4.6 | -32.4 -26.3 285 20 10 8.6 4.7  
24000 -29.5 -21.1 285 23 12 7.7 4.2 | -29.8 -21.6 285 20 10 8.5 4.7  
23000 -27.6 -17.7 285 21 11 6.2 3.4 | -27.3 -17.1 285 19 10 8.3 4.6  
22000 -25.7 -14.3 285 18 10 6.3 3.4 | -24.2 -11.6 285 19 10 8.3 4.5  
21000 -23.6 -10.5 285 16 8 3.6 2.0 | -22.1 -7.8 285 17 9 4.1 2.2  
20000 -22.5 -8.5 285 13 7 3.8 2.1 | -20.8 -5.4 285 15 7 4.3 2.4  
19500 -21.9 -7.4 285 11 6 3.8 2.1 | -20.2 -4.4 280 13 7 4.3 2.4  
19000 -21.3 -6.3 285 10 5 3.6 2.0 | -19.5 -3.1 280 12 6 4.3 2.4  
18500 -20.6 -5.1 285 9 5 5.4 2.9 | -18.9 -2.0 275 11 6 4.1 2.2  
18000 -19.9 -3.8 285 8 4 5.2 2.9 | -18.3 -0.9 275 10 5 4.1 2.3  
17500 -19.1 -2.4 285 8 4 5.4 3.0 | -17.7 0.1 270 9 4 4.4 2.4  
17000 -18.2 -0.8 280 7 4 5.6 3.1 | -17.0 1.4 270 8 4 4.6 2.5  
16500 -17.4 0.7 280 6 3 5.8 3.2 | -16.3 2.7 265 7 4 4.8 2.6  
16000 -16.5 2.3 275 6 3 6.7 3.7 | -15.5 4.1 260 7 3 5.7 3.1  
15500 -15.5 4.1 270 5 3 6.6 3.6 | -14.6 5.7 260 6 3 5.6 3.1  
15000 -14.5 5.9 265 4 2 6.6 3.6 | -13.8 7.2 255 6 3 6.2 3.4  
14500 -13.5 7.7 260 4 2 6.6 3.6 | -12.8 9.0 250 5 3 6.1 3.4  
14000 -12.5 9.5 250 3 2 6.9 3.8 | -11.9 10.6 245 5 3 6.8 3.7  
13500 -11.5 11.3 240 3 1 6.9 3.8 | -10.9 12.4 240 4 2 6.8 3.7  
13000 -10.4 13.3 225 2 1 6.9 3.8 | -9.8 14.4 230 4 2 6.8 3.7  
12500 -9.4 15.1 210 2 1 7.0 3.8 | -8.8 16.2 220 4 2 6.8 3.7  
12000 -8.4 16.9 200 2 1 6.6 3.6 | -7.8 18.0 210 4 2 6.6 3.6  
11500 -7.4 18.7 185 2 1 6.6 3.6 | -6.8 19.8 200 3 2 6.6 3.6  
11000 -6.4 20.5 175 2 1 6.0 3.3 | -5.9 21.4 190 3 2 6.3 3.4  
10500 -5.6 21.9 170 2 1 6.2 3.4 | -5.0 23.0 180 3 2 6.4 3.5  
10250 -5.1 22.8 165 2 1 5.0 2.8 | -4.5 23.9 175 3 2 5.5 3.0  
10000 -4.8 23.4 165 3 1 3.7 2.1 | -4.1 24.6 175 3 2 5.7 3.1  
9750 -4.5 23.9 165 3 1 4.0 2.2 | -3.7 25.3 170 3 2 3.7 2.0  
9500 -4.2 24.4 155 3 1 4.0 2.2 | -3.3 26.1 165 3 1 14.2 7.8  
9250 -3.9 25.0 150 2 1 4.1 2.3 | -1.9 28.6 135 2 1 10.4 5.7  
9000 -3.6 25.5 150 2 1 5.0 2.7 | -1.9 28.6 135 2 1 -2.5 -1.4  
8750 -3.3 26.1 145 2 1 0.6 0.3 | -1.9 28.6 135 2 1 0.6 0.3  
8500 -3.5 25.7 135 2 1 -0.8 -0.5 | -1.9 28.6 135 2 1 1.2 0.7  
8250 -3.4 25.9 125 2 1 3.1 1.7 | -1.7 28.9 130 2 1 4.1 2.3  
8000 -3.1 26.4 115 2 1 4.3 2.4 | -1.4 29.5 120 2 1 6.1 3.4  
7750 -2.8 27.0 105 1 1 1.1 0.6 | -1.0 30.2 110 2 1 1.3 0.7  
7500 -2.8 27.0 080 2 1 3.1 1.7 | -0.6 30.9 085 2 1 7.9 4.3  
7250 -1.8 28.8 065 1 1 6.1 3.4 | -0.1 31.8 075 2 1 6.7 3.7  
7000 -1.3 29.7 060 1 1 8.3 4.5 | 0.4 32.7 065 2 1 6.0 3.3  
6750 -0.6 30.9 055 2 1 9.9 5.5 | 0.9 33.6 060 2 1 7.1 3.9  
6500 0.1 32.2 055 1 1 9.4 5.1 | 1.5 34.7 055 2 1 8.7 4.8  
6250 0.8 33.4 050 1 1 9.7 5.3 | 2.1 35.8 050 1 1 9.3 5.1  
6000 1.6 34.9 050 1 1 13.9 7.6 | 2.9 37.2 045 2 1 11.1 6.1  
5750 2.9 37.2 045 1 1 20.3 11.2 | 3.7 38.7 045 2 1 10.0 5.5  
5500 4.2 39.6 040 1 1 9.9 5.4 | 4.5 40.1 040 1 1 12.8 7.0  
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.  
 
042613  
 
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