804  
UXUS97 KGJT 201240  
SRGGJT  
 
SOARING FORECAST  
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO  
0640 MDT SATURDAY, APRIL 20, 2019  
 
THIS FORECAST IS FOR SATURDAY, APRIL 20, 2019:  
 
IF THE TRIGGER TEMPERATURE OF 74.9 F/23.9 C IS REACHED...THEN  
THERMAL SOARING INDEX....................... FAIR  
MAXIMUM RATE OF LIFT........................ 350 FT/MIN (1.8 M/S)  
MAXIMUM HEIGHT OF THERMALS.................. 9701 FT MSL (4862 FT AGL)  
 
FORECAST MAXIMUM TEMPERATURE................... 76.0 F/24.9 C  
TIME OF TRIGGER TEMPERATURE.................... 1145 MDT  
TIME OF OVERDEVELOPMENT........................ 1300 MDT  
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... NONE  
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS  
HEIGHT OF THE -3 THERMAL INDEX................. 7030 FT MSL (2191 FT AGL)  
THERMAL SOARING OUTLOOK FOR SUNDAY 04/21....... GOOD  
 
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.................... 06:30:06 / 19:55:58 MDT  
TOTAL POSSIBLE SUNSHINE........... 13 HR 25 MIN 52 SEC (805 MIN 52 SEC)  
ALTITUDE OF SUN AT 13:13:02 MDT... 62.34 DEGREES  
 
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 04/20/2019 AT 0600 MDT  
 
FREEZING LEVEL.................. 13304 FT MSL (8465 FT AGL)  
CONVECTIVE CONDENSATION LEVEL... 19708 FT MSL (14869 FT AGL)  
LIFTED CONDENSATION LEVEL....... 18331 FT MSL (13492 FT AGL)  
LIFTED INDEX.................... +1.0  
K INDEX......................... +6.7  
 
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 -63.2 -81.8 275 32 17 4.8 2.6 93.6 200.5 39.6 M M  
45000 -55.3 -67.5 255 43 22 2.9 1.6 81.1 177.9 34.8 M M  
40000 -56.5 -69.7 245 39 20 -1.5 -0.8 56.4 133.6 21.0 M M  
38000 -55.3 -67.5 230 40 21 4.1 2.2 49.4 121.0 16.9 M M  
36000 -52.9 -63.2 235 42 22 3.8 2.1 44.3 111.7 13.7 M M  
34000 -49.3 -56.7 230 45 23 6.2 3.4 41.1 105.9 11.9 M M  
32000 -44.5 -48.1 230 38 19 9.0 4.9 38.6 101.5 10.4 M M  
30000 -39.4 -38.9 230 32 16 7.6 4.1 37.7 99.8 9.9 M M  
29000 -37.3 -35.1 230 29 15 2.7 1.5 36.6 97.9 9.2 M M  
28000 -35.8 -32.4 225 26 13 8.9 4.9 34.8 94.6 7.9 M M  
27000 -33.1 -27.6 225 28 15 8.8 4.9 34.4 93.9 7.7 M M  
26000 -30.7 -23.3 230 31 16 8.2 4.5 33.8 92.9 7.4 M M  
25000 -28.3 -18.9 230 33 17 7.7 4.2 33.2 91.8 6.9 M M  
24000 -26.8 -16.2 220 33 17 -2.5 -1.4 31.4 88.6 5.6 M M  
23000 -25.6 -14.1 225 30 16 8.9 4.9 29.3 84.8 3.9 M M  
22000 -22.8 -9.0 230 28 14 9.0 4.9 29.0 84.3 3.8 M M  
21000 -20.1 -4.2 240 26 13 9.0 4.9 28.7 83.7 3.6 M M  
20000 -17.4 0.7 250 24 12 9.0 4.9 28.5 83.4 3.5 M M  
19500 -16.0 3.2 250 25 13 9.0 4.9 28.4 83.1 3.4 M M  
19000 -14.7 5.5 250 26 13 8.9 4.9 28.2 82.8 3.3 M M  
18500 -13.4 7.9 250 28 14 8.3 4.6 28.0 82.5 3.1 M M  
18000 -11.7 10.9 245 33 17 7.9 4.3 27.6 81.6 2.6 M M  
17500 -10.5 13.1 240 36 19 7.7 4.2 27.3 81.1 2.3 M M  
17000 -9.4 15.1 240 39 20 3.9 2.2 27.0 80.6 2.0 M M  
16500 -8.7 16.3 235 37 19 9.9 5.5 26.2 79.2 1.3 M M  
16000 -7.3 18.9 235 35 18 8.7 4.8 26.0 78.9 1.2 M M  
15500 -6.0 21.2 235 33 17 9.5 5.2 25.9 78.6 1.0 M M  
15000 -4.6 23.7 235 31 16 9.4 5.2 25.8 78.5 1.0 M M  
14500 -3.2 26.2 235 30 15 9.4 5.2 25.8 78.4 0.9 M M  
14000 -1.8 28.8 235 28 14 9.0 4.9 25.7 78.3 0.9 M M  
13500 -0.4 31.3 235 26 13 9.0 4.9 25.6 78.1 0.8 M M  
13000 1.0 33.8 235 23 12 9.0 4.9 25.5 77.9 0.7 M M  
12500 2.3 36.1 230 21 11 9.0 4.9 25.4 77.7 0.6 M M  
12000 3.7 38.7 230 19 10 9.0 4.9 25.3 77.5 0.5 M M  
11500 5.0 41.0 230 18 9 9.0 4.9 25.1 77.2 0.4 M M  
11000 6.3 43.3 230 17 9 9.0 4.9 25.0 77.0 0.3 M M  
10500 7.7 45.9 230 17 9 9.0 5.0 24.9 76.8 0.2 M M  
10250 8.4 47.1 230 16 8 9.0 4.9 24.8 76.7 0.1 M M  
10000 9.0 48.2 230 15 8 9.0 5.0 24.8 76.6 0.1 M M  
9750 9.7 49.5 230 14 7 8.9 4.9 24.7 76.5 0.0 M M  
9500 10.4 50.7 230 13 7 7.9 4.3 24.6 76.3 -0.1 330 1.7  
9250 10.9 51.6 235 11 6 7.3 4.0 24.5 76.0 -0.2 307 1.6  
9000 11.5 52.7 235 10 5 7.4 4.1 24.3 75.7 -0.4 283 1.4  
8750 12.0 53.6 235 9 5 7.4 4.1 24.1 75.4 -0.6 259 1.3  
8500 12.5 54.5 230 8 4 7.4 4.1 23.9 75.0 -0.8 235 1.2  
8250 13.1 55.6 225 6 3 7.5 4.1 23.7 74.7 -1.0 212 1.1  
8000 13.6 56.5 220 5 3 7.1 3.9 23.6 74.4 -1.2 188 1.0  
7750 14.1 57.4 195 6 3 4.7 2.6 23.3 73.9 -1.5 167 0.8  
7500 14.3 57.7 180 7 4 3.2 1.7 22.8 73.0 -2.0 153 0.8  
7250 14.5 58.1 170 9 5 3.6 2.0 22.3 72.2 -2.5 138 0.7  
7000 14.8 58.6 160 11 6 3.4 1.9 21.8 71.3 -3.0 124 0.6  
6750 15.0 59.0 155 13 7 3.9 2.2 21.4 70.5 -3.5 109 0.6  
6500 14.8 58.6 155 15 8 -14.4 -7.9 20.5 68.9 -4.4 107 0.5  
6250 13.4 56.1 150 17 9 -7.8 -4.3 18.3 65.0 -6.5 143 0.7  
6000 13.9 57.0 150 19 10 7.6 4.1 18.0 64.5 -6.8 122 0.6  
5750 14.0 57.2 145 18 9 -1.2 -0.6 17.4 63.3 -7.5 112 0.6  
5500 13.9 57.0 145 15 8 -0.7 -0.4 16.6 61.9 -8.3 106 0.5  
5250 13.9 57.0 135 12 6 0.9 0.5 15.8 60.5 -9.1 100 0.5  
5000 13.8 56.8 125 10 5 -5.9 -3.2 15.1 59.1 -9.9 94 0.5  
 
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *  
 
04/20/2019 AT 0900 MDT | 04/20/2019 AT 1200 MDT  
|  
CAPE... 0.0 LI... +1.7 | CAPE... +12.6 LI... +0.3  
CINH... -1.6 K INDEX... +8.5 | CINH... -15.3 K INDEX... +16.0  
|  
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 -59.5 -75.1 255 13 7 3.8 2.1 | -58.5 -73.3 245 14 7 4.0 2.2  
45000 -54.2 -65.6 245 16 8 -0.1 -0.1 | -53.0 -63.4 240 18 9 0.7 0.4  
40000 -54.5 -66.1 230 18 9 -0.2 -0.1 | -52.2 -62.0 225 20 10 0.6 0.3  
38000 -53.3 -63.9 225 19 10 3.1 1.7 | -51.7 -61.1 215 20 10 1.0 0.6  
36000 -51.5 -60.7 220 19 10 3.1 1.7 | -51.1 -60.0 210 20 10 1.0 0.6  
34000 -48.7 -55.7 220 19 10 5.9 3.2 | -49.4 -56.9 205 20 10 5.5 3.0  
32000 -45.2 -49.4 215 19 10 5.9 3.2 | -46.2 -51.2 205 21 11 5.4 3.0  
30000 -41.4 -42.5 210 18 9 7.1 3.9 | -42.5 -44.5 205 21 11 7.4 4.1  
29000 -39.3 -38.7 210 18 9 7.1 3.9 | -40.3 -40.5 205 21 11 7.4 4.1  
28000 -37.2 -35.0 210 18 9 7.1 3.9 | -38.1 -36.6 205 21 11 7.4 4.1  
27000 -35.0 -31.0 210 17 9 7.4 4.1 | -35.8 -32.4 210 21 11 8.2 4.5  
26000 -32.8 -27.0 210 17 9 7.4 4.1 | -33.4 -28.1 210 20 10 8.2 4.5  
25000 -30.6 -23.1 215 16 8 7.4 4.1 | -31.0 -23.8 210 18 10 8.2 4.5  
24000 -28.4 -19.1 215 15 8 7.8 4.3 | -28.5 -19.3 210 17 9 7.6 4.2  
23000 -26.0 -14.8 220 15 8 7.9 4.3 | -26.3 -15.3 210 16 8 7.4 4.1  
22000 -23.6 -10.5 220 14 7 7.9 4.3 | -24.1 -11.4 210 16 8 7.4 4.1  
21000 -21.2 -6.2 225 14 7 8.3 4.6 | -21.9 -7.4 210 15 8 8.2 4.5  
20000 -18.2 -0.8 225 14 7 8.3 4.6 | -18.9 -2.0 215 14 7 8.1 4.5  
19500 -16.9 1.6 230 14 7 8.3 4.6 | -17.7 0.1 215 14 7 8.1 4.5  
19000 -15.7 3.7 230 14 7 8.4 4.6 | -16.5 2.3 215 14 7 8.2 4.5  
18500 -14.4 6.1 230 14 7 8.6 4.7 | -15.2 4.6 220 14 7 8.6 4.7  
18000 -13.2 8.2 230 14 7 8.6 4.7 | -14.0 6.8 220 13 7 8.6 4.7  
17500 -11.9 10.6 230 14 7 8.9 4.9 | -12.7 9.1 220 13 7 8.8 4.8  
17000 -10.6 12.9 230 14 7 8.9 4.9 | -11.4 11.5 220 13 6 8.9 4.9  
16500 -9.3 15.3 230 14 7 9.0 4.9 | -10.0 14.0 220 12 6 9.0 4.9  
16000 -7.9 17.8 230 13 7 9.1 5.0 | -8.7 16.3 220 12 6 9.3 5.1  
15500 -6.5 20.3 230 13 7 9.1 5.0 | -7.3 18.9 220 11 6 9.3 5.1  
15000 -5.2 22.6 225 13 6 8.9 4.9 | -5.9 21.4 220 11 6 9.2 5.0  
14500 -3.9 25.0 225 12 6 8.9 4.9 | -4.5 23.9 220 11 6 9.1 5.0  
14000 -2.6 27.3 225 12 6 8.8 4.8 | -3.2 26.2 220 11 6 9.3 5.1  
13500 -1.3 29.7 225 11 6 8.9 4.9 | -1.8 28.8 220 11 6 9.3 5.1  
13000 0.0 32.0 225 11 6 8.7 4.8 | -0.4 31.3 220 11 6 9.2 5.0  
12500 1.3 34.3 225 11 6 8.7 4.8 | 1.0 33.8 220 11 5 9.1 5.0  
12000 2.6 36.7 225 10 5 8.4 4.6 | 2.3 36.1 220 10 5 8.8 4.8  
11500 3.9 39.0 225 10 5 8.4 4.6 | 3.6 38.5 215 10 5 8.7 4.8  
11000 5.1 41.2 225 9 5 7.0 3.8 | 4.9 40.8 215 9 5 7.8 4.3  
10500 6.1 43.0 220 8 4 5.4 3.0 | 6.0 42.8 210 9 5 6.4 3.5  
10250 6.5 43.7 220 8 4 10.5 5.8 | 6.5 43.7 210 9 4 10.4 5.7  
10000 7.5 45.5 220 8 4 11.3 6.2 | 7.5 45.5 210 8 4 11.5 6.3  
9750 8.1 46.6 215 8 4 6.5 3.6 | 8.1 46.6 205 8 4 8.1 4.4  
9500 8.7 47.7 215 8 4 8.1 4.5 | 8.8 47.8 205 8 4 9.4 5.2  
9250 9.2 48.6 210 7 4 6.4 3.5 | 9.4 48.9 205 8 4 7.4 4.1  
9000 9.7 49.5 210 7 4 6.3 3.5 | 9.9 49.8 200 7 4 7.7 4.2  
8750 10.2 50.4 205 7 4 7.6 4.2 | 10.6 51.1 200 7 4 9.6 5.3  
8500 10.7 51.3 200 7 4 7.2 3.9 | 11.3 52.3 195 7 4 9.2 5.1  
8250 11.3 52.3 195 7 4 7.8 4.3 | 12.0 53.6 195 7 4 8.8 4.8  
8000 11.9 53.4 195 7 4 7.0 3.8 | 12.6 54.7 190 7 3 7.9 4.3  
7750 12.3 54.1 190 7 4 4.6 2.5 | 13.2 55.8 190 6 3 7.8 4.3  
7500 12.6 54.7 180 7 3 3.8 2.1 | 13.8 56.8 185 6 3 8.0 4.4  
7250 12.9 55.2 175 7 3 4.6 2.5 | 14.4 57.9 185 6 3 7.5 4.1  
7000 13.2 55.8 170 7 3 5.0 2.7 | 14.9 58.8 180 6 3 7.2 3.9  
6750 13.5 56.3 165 7 3 3.0 1.7 | 15.5 59.9 175 6 3 8.3 4.6  
6500 13.6 56.5 155 6 3 1.8 1.0 | 16.1 61.0 175 5 3 9.1 5.0  
6250 13.8 56.8 150 6 3 2.0 1.1 | 16.8 62.2 175 5 2 9.4 5.2  
6000 13.9 57.0 145 5 3 2.3 1.2 | 17.5 63.5 175 4 2 10.6 5.8  
5750 13.9 57.0 120 3 2 -0.3 -0.2 | 18.2 64.8 175 4 2 7.1 3.9  
5500 14.4 57.9 110 3 2 23.0 12.6 | 20.7 69.3 170 3 2 62.4 34.3  
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  
 
04/20/2019 AT 1500 MDT | 04/20/2019 AT 1800 MDT  
|  
CAPE... +390.6 LI... -0.2 | CAPE... +359.1 LI... -0.4  
CINH... -17.9 K INDEX... +24.2 | CINH... -35.1 K INDEX... +24.0  
|  
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 -58.3 -72.9 240 13 7 4.2 2.3 | -57.7 -71.9 240 14 7 3.9 2.2  
45000 -52.2 -62.0 235 16 8 1.0 0.5 | -51.9 -61.4 235 15 8 1.0 0.5  
40000 -50.9 -59.6 230 20 10 0.9 0.5 | -50.4 -58.7 240 18 9 1.0 0.5  
38000 -50.7 -59.3 220 20 10 0.1 0.1 | -50.3 -58.5 235 17 9 -0.3 -0.2  
36000 -50.6 -59.1 210 21 11 0.1 0.1 | -50.5 -58.9 225 16 8 -0.3 -0.2  
34000 -49.8 -57.6 200 22 11 3.6 2.0 | -50.3 -58.5 210 15 8 3.4 1.9  
32000 -47.7 -53.9 200 21 11 3.6 2.0 | -48.2 -54.8 190 13 7 3.1 1.7  
30000 -44.4 -47.9 195 19 10 9.3 5.1 | -45.2 -49.4 180 13 7 9.1 5.0  
29000 -41.6 -42.9 200 18 9 9.3 5.1 | -42.4 -44.3 180 13 7 9.2 5.0  
28000 -38.8 -37.8 200 17 9 9.3 5.1 | -39.7 -39.5 185 13 7 9.2 5.0  
27000 -36.1 -33.0 200 16 8 8.5 4.6 | -37.0 -34.6 190 12 6 8.8 4.9  
26000 -33.6 -28.5 200 15 8 8.5 4.6 | -34.3 -29.7 195 13 6 8.8 4.8  
25000 -31.0 -23.8 200 15 8 8.5 4.6 | -31.7 -25.1 200 13 7 8.8 4.8  
24000 -28.5 -19.3 200 14 7 8.2 4.5 | -29.1 -20.4 205 13 7 8.6 4.7  
23000 -26.2 -15.2 200 14 7 8.0 4.4 | -26.6 -15.9 210 13 7 8.4 4.6  
22000 -23.8 -10.8 195 14 7 8.0 4.4 | -24.1 -11.4 215 13 7 8.4 4.6  
21000 -21.4 -6.5 195 14 7 7.9 4.3 | -21.7 -7.1 220 13 7 8.0 4.4  
20000 -19.1 -2.4 195 14 7 7.9 4.3 | -19.4 -2.9 220 13 7 7.9 4.3  
19500 -17.9 -0.2 190 14 7 7.9 4.4 | -18.2 -0.8 220 13 7 7.9 4.3  
19000 -16.2 2.8 190 13 7 7.9 4.3 | -16.4 2.5 220 13 7 7.9 4.4  
18500 -15.1 4.8 190 13 7 7.3 4.0 | -15.3 4.5 220 13 7 7.8 4.3  
18000 -14.0 6.8 195 13 7 7.3 4.0 | -14.1 6.6 220 13 7 7.9 4.3  
17500 -12.9 8.8 195 13 7 7.4 4.1 | -13.0 8.6 220 13 7 7.8 4.3  
17000 -11.8 10.8 195 13 6 7.4 4.1 | -11.8 10.8 220 13 7 7.8 4.3  
16500 -10.7 12.7 195 12 6 7.5 4.1 | -10.7 12.7 220 13 7 7.8 4.3  
16000 -9.6 14.7 200 12 6 7.4 4.1 | -9.6 14.7 220 13 6 7.7 4.2  
15500 -8.5 16.7 200 12 6 7.4 4.0 | -8.4 16.9 220 12 6 7.7 4.2  
15000 -7.3 18.9 200 11 6 8.8 4.9 | -7.3 18.9 215 12 6 7.7 4.2  
14500 -6.0 21.2 205 11 6 8.7 4.8 | -6.2 20.8 215 12 6 7.7 4.2  
14000 -4.7 23.5 205 11 6 9.1 5.0 | -5.0 23.0 215 11 6 8.2 4.5  
13500 -3.3 26.1 210 11 5 9.2 5.0 | -3.8 25.2 215 11 6 8.3 4.6  
13000 -2.0 28.4 210 11 5 9.4 5.1 | -2.6 27.3 215 11 5 8.8 4.8  
12500 -0.5 31.1 215 10 5 9.4 5.2 | -1.2 29.8 215 10 5 9.1 5.0  
12000 0.9 33.6 215 10 5 9.6 5.2 | 0.2 32.4 215 10 5 9.3 5.1  
11500 2.3 36.1 220 10 5 9.6 5.3 | 1.6 34.9 215 9 5 9.4 5.2  
11000 3.7 38.7 220 10 5 8.5 4.7 | 3.0 37.4 215 8 4 8.6 4.7  
10500 4.9 40.8 220 10 5 6.5 3.6 | 4.1 39.4 210 8 4 6.4 3.5  
10250 5.5 41.9 220 10 5 12.5 6.9 | 4.7 40.5 210 8 4 10.7 5.9  
10000 6.6 43.9 225 10 5 13.5 7.4 | 5.6 42.1 210 7 4 12.2 6.7  
9750 7.3 45.1 225 10 5 7.9 4.3 | 6.4 43.5 210 7 3 8.6 4.7  
9500 8.0 46.4 225 10 5 10.2 5.6 | 7.0 44.6 210 6 3 8.8 4.8  
9250 8.7 47.7 225 10 5 6.6 3.6 | 7.7 45.9 210 6 3 9.7 5.3  
9000 9.1 48.4 230 10 5 7.6 4.2 | 8.4 47.1 210 6 3 9.8 5.4  
8750 9.9 49.8 230 9 5 11.2 6.2 | 9.1 48.4 210 5 3 8.8 4.9  
8500 10.7 51.3 230 9 5 10.7 5.9 | 9.8 49.6 210 5 2 9.1 5.0  
8250 11.5 52.7 235 9 5 9.2 5.0 | 10.4 50.7 210 4 2 9.0 4.9  
8000 12.0 53.6 235 9 5 7.7 4.2 | 11.1 52.0 210 4 2 8.7 4.8  
7750 12.7 54.9 240 9 5 9.5 5.2 | 11.7 53.1 210 3 2 8.4 4.6  
7500 13.4 56.1 240 9 4 10.5 5.8 | 12.4 54.3 205 3 2 8.6 4.7  
7250 14.2 57.6 240 8 4 8.7 4.8 | 13.0 55.4 205 2 1 8.1 4.4  
7000 14.7 58.5 240 9 4 7.2 4.0 | 13.5 56.3 210 2 1 7.4 4.0  
6750 15.4 59.7 245 9 5 9.9 5.4 | 14.1 57.4 220 2 1 8.2 4.5  
6500 16.2 61.2 245 8 4 11.3 6.2 | 14.7 58.5 215 1 1 8.6 4.7  
6250 16.9 62.4 245 8 4 9.8 5.4 | 15.4 59.7 215 1 0 9.3 5.1  
6000 17.6 63.7 245 8 4 9.3 5.1 | 16.1 61.0 240 1 0 10.5 5.8  
5750 18.3 64.9 245 8 4 9.0 5.0 | 16.8 62.2 280 1 0 8.2 4.5  
5500 19.0 66.2 245 7 4 10.3 5.6 | 17.3 63.1 245 1 0 7.5 4.1  
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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