719
UXUS97 KBOU 101500
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
0859 MDT MONDAY, AUGUST 10, 2026
THIS FORECAST IS FOR MONDAY, AUGUST 10, 2026:
IF THE TRIGGER TEMPERATURE OF 87.0 F/30.6 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1469 FT/MIN (7.5 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 20760 FT MSL (15397 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 98.0 F/37.1 C
TIME OF TRIGGER TEMPERATURE.................... 1015 MDT
TIME OF OVERDEVELOPMENT........................ 1700 MDT
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... BROKEN/OVERCAST THIN MIDDLE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 15506 FT MSL (10143 FT AGL)
THERMAL SOARING OUTLOOK FOR TUESDAY 08/11...... EXCELLENT
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1800 MDT)......... TRENDING THE SAME
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1800 MDT)................ WEAK PVA
POTENTIAL HEIGHT OF WAVE....................... 22066 FT MSL (16703 FT AGL)
WAVE SOARING OUTLOOK FOR TUESDAY 08/11......... POOR
REMARKS...
SUNRISE/SUNSET.................... 06:07:14 / 20:02:24 MDT
TOTAL POSSIBLE SUNSHINE........... 13 HR 55 MIN 9 SEC (835 MIN 9 SEC)
ALTITUDE OF SUN AT 13:04:49 MDT... 65.59 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 08/10/2026 AT 0600 MDT
FREEZING LEVEL.................. 16590 FT MSL (11227 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 17231 FT MSL (11868 FT AGL)
LIFTED CONDENSATION LEVEL....... 18480 FT MSL (13117 FT AGL)
LIFTED INDEX.................... -3.0
K INDEX......................... +25.2
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 -64.4 -83.9 290 29 15 0.3 0.2 M M M M M
45000 -61.3 -78.3 290 38 20 5.2 2.9 M M M M M
40000 -53.1 -63.6 305 35 18 6.9 3.8 M M M M M
38000 -48.9 -56.0 300 31 16 6.9 3.8 M M M M M
36000 -44.8 -48.6 295 28 14 7.4 4.0 M M M M M
34000 -39.6 -39.3 290 24 12 8.7 4.8 M M M M M
32000 -33.7 -28.7 275 21 11 9.1 5.0 M M M M M
30000 -28.8 -19.8 275 20 10 8.2 4.5 46.5 115.7 7.4 M M
29000 -26.4 -15.5 270 19 10 8.2 4.5 46.0 114.7 7.1 M M
28000 -24.0 -11.2 275 18 9 7.5 4.1 45.4 113.6 6.7 M M
27000 -21.8 -7.2 275 18 9 7.6 4.2 44.4 112.0 6.0 M M
26000 -19.5 -3.1 280 18 9 7.6 4.2 43.6 110.5 5.4 M M
25000 -17.3 0.9 285 17 9 6.7 3.7 42.9 109.3 4.9 M M
24000 -15.6 3.9 280 19 10 6.0 3.3 41.4 106.6 3.7 M M
23000 -13.8 7.2 275 21 11 6.1 3.3 40.1 104.1 2.5 M M
22000 -12.1 10.2 270 23 12 6.3 3.5 38.9 102.0 1.4 M M
21000 -10.2 13.6 270 23 12 6.6 3.6 37.6 99.7 0.3 M M
20000 -8.3 17.1 270 24 12 6.6 3.6 36.5 97.8 -0.7 1412 7.2
19500 -7.4 18.7 270 24 12 6.6 3.6 36.0 96.8 -1.2 1369 7.0
19000 -6.3 20.7 270 23 12 7.8 4.3 35.6 96.1 -1.6 1322 6.7
18500 -4.6 23.7 270 21 11 7.6 4.2 35.1 95.1 -2.1 1250 6.4
18000 -3.4 25.9 275 19 10 8.7 4.8 34.8 94.6 -2.4 1200 6.1
17500 -2.2 28.0 275 18 9 8.6 4.7 34.6 94.3 -2.6 1147 5.8
17000 -0.9 30.4 275 17 9 9.0 5.0 34.4 94.0 -2.7 1094 5.6
16500 0.5 32.9 275 16 8 9.3 5.1 34.4 93.8 -2.8 1037 5.3
16000 1.9 35.4 270 15 8 9.3 5.1 34.3 93.7 -2.9 981 5.0
15500 3.3 37.9 265 15 8 9.1 5.0 34.2 93.5 -3.0 925 4.7
15000 4.6 40.3 265 14 7 9.2 5.0 34.1 93.4 -3.1 869 4.4
14500 5.9 42.6 260 13 7 8.8 4.8 34.0 93.2 -3.3 815 4.1
14000 7.2 45.0 250 12 6 8.8 4.8 33.8 92.9 -3.4 761 3.9
13500 8.5 47.3 245 11 6 8.5 4.7 33.6 92.6 -3.6 708 3.6
13000 9.8 49.6 235 10 5 8.5 4.6 33.4 92.2 -3.9 656 3.3
12500 11.0 51.8 225 10 5 8.4 4.6 33.2 91.8 -4.1 604 3.1
12000 12.2 54.0 215 9 5 8.4 4.6 33.0 91.4 -4.4 552 2.8
11500 13.5 56.3 205 8 4 8.4 4.6 32.8 91.1 -4.6 501 2.5
11000 14.7 58.5 200 7 4 8.1 4.4 32.6 90.6 -4.9 450 2.3
10500 15.9 60.6 190 7 3 5.6 3.1 32.4 90.2 -5.2 399 2.0
10250 16.2 61.2 190 7 3 6.4 3.5 31.9 89.5 -5.6 383 1.9
10000 16.9 62.4 180 6 3 10.3 5.7 31.9 89.4 -5.6 354 1.8
9750 17.6 63.7 175 5 3 9.6 5.3 31.9 89.4 -5.7 326 1.7
9500 18.3 64.9 160 5 2 8.6 4.7 31.9 89.4 -5.7 298 1.5
9250 18.8 65.8 150 5 2 6.9 3.8 31.7 89.1 -5.9 274 1.4
9000 19.3 66.7 145 4 2 7.8 4.3 31.5 88.7 -6.1 251 1.3
8750 20.0 68.0 140 4 2 8.6 4.7 31.4 88.5 -6.2 225 1.1
8500 20.6 69.1 130 4 2 7.6 4.2 31.3 88.3 -6.4 199 1.0
8250 21.1 70.0 130 4 2 6.4 3.5 31.1 87.9 -6.6 177 0.9
8000 21.5 70.7 125 4 2 6.1 3.3 30.8 87.4 -6.9 155 0.8
7750 22.0 71.6 135 3 2 6.1 3.4 30.5 86.9 -7.2 134 0.7
7500 22.5 72.5 155 3 1 5.0 2.7 30.2 86.4 -7.5 113 0.6
7250 22.8 73.0 175 3 2 3.7 2.0 29.8 85.6 -7.9 97 0.5
7000 23.1 73.6 190 4 2 4.1 2.2 29.3 84.8 -8.3 80 0.4
6750 23.3 73.9 200 5 3 3.6 2.0 28.9 84.0 -8.8 64 0.3
6500 23.5 74.3 205 6 3 -0.8 -0.4 28.3 82.9 -9.4 54 0.3
6250 23.2 73.8 205 7 3 -3.8 -2.1 27.3 81.2 -10.5 55 0.3
6000 22.9 73.2 205 7 4 -2.4 -1.3 26.4 79.4 -11.5 56 0.3
5750 22.6 72.7 205 8 4 -4.8 -2.6 25.4 77.7 -12.5 57 0.3
5500 22.0 71.6 205 6 3 -11.0 -6.0 24.1 75.3 -13.9 66 0.3
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
08/10/2026 AT 0900 MDT | 08/10/2026 AT 1200 MDT
|
CAPE... 0.0 LI... -1.1 | CAPE... +190.7 LI... -1.0
CINH... -1.3 K INDEX... +25.7 | CINH... -20.1 K INDEX... +26.0
|
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 -64.7 -84.5 290 29 15 0.6 0.4 | -65.3 -85.5 290 25 13 1.6 0.9
45000 -61.3 -78.3 295 40 21 5.2 2.8 | -60.8 -77.4 300 35 18 5.2 2.9
40000 -53.2 -63.8 300 33 17 7.0 3.8 | -52.7 -62.9 300 34 18 6.8 3.7
38000 -49.0 -56.2 295 30 15 7.0 3.8 | -48.6 -55.5 290 31 16 6.8 3.7
36000 -44.9 -48.8 290 26 13 7.4 4.1 | -44.5 -48.1 285 28 15 7.3 4.0
34000 -39.6 -39.3 280 23 12 8.8 4.8 | -39.3 -38.7 280 26 13 8.7 4.8
32000 -33.7 -28.7 265 20 11 9.1 5.0 | -33.5 -28.3 270 24 12 8.9 4.9
30000 -28.9 -20.0 255 17 9 8.1 4.5 | -28.8 -19.8 260 22 11 7.9 4.4
29000 -26.5 -15.7 250 16 8 8.1 4.5 | -26.4 -15.5 255 21 11 8.0 4.4
28000 -24.1 -11.4 250 15 8 7.1 3.9 | -24.2 -11.6 250 21 11 6.6 3.6
27000 -22.0 -7.6 250 14 7 7.2 3.9 | -22.2 -8.0 240 21 11 6.7 3.7
26000 -19.9 -3.8 245 13 7 7.2 4.0 | -20.2 -4.4 235 22 11 6.7 3.7
25000 -17.8 -0.0 245 13 6 6.6 3.6 | -18.3 -0.9 230 22 11 6.7 3.7
24000 -16.0 3.2 255 14 7 6.2 3.4 | -16.3 2.7 235 21 11 6.7 3.7
23000 -14.1 6.6 260 16 8 6.3 3.4 | -14.3 6.3 240 20 10 6.7 3.7
22000 -12.3 9.9 265 18 9 6.6 3.6 | -12.4 9.7 245 19 10 7.0 3.9
21000 -10.3 13.5 265 20 10 6.8 3.7 | -10.3 13.5 245 18 9 7.2 4.0
20000 -8.3 17.1 265 22 11 6.9 3.8 | -8.2 17.2 250 18 9 7.2 4.0
19500 -7.3 18.9 270 23 12 7.0 3.9 | -7.2 19.0 250 17 9 7.2 4.0
19000 -5.6 21.9 270 21 11 8.1 4.4 | -5.6 21.9 250 16 8 7.2 3.9
18500 -4.5 23.9 270 20 10 8.2 4.5 | -4.6 23.7 250 15 8 7.3 4.0
18000 -3.3 26.1 270 18 9 8.4 4.6 | -3.4 25.9 250 14 7 8.4 4.6
17500 -2.0 28.4 275 16 8 8.4 4.6 | -2.2 28.0 250 13 6 8.3 4.6
17000 -0.8 30.6 275 14 7 8.9 4.9 | -0.9 30.4 250 12 6 9.0 4.9
16500 0.6 33.1 275 13 6 9.1 5.0 | 0.4 32.7 250 11 6 9.2 5.0
16000 1.9 35.4 275 11 6 9.1 5.0 | 1.8 35.2 250 10 5 9.2 5.1
15500 3.3 37.9 270 10 5 9.3 5.1 | 3.2 37.8 255 10 5 9.4 5.1
15000 4.7 40.5 270 9 4 9.3 5.1 | 4.6 40.3 255 9 5 9.4 5.1
14500 6.0 42.8 265 8 4 9.2 5.1 | 6.0 42.8 260 9 5 9.3 5.1
14000 7.4 45.3 260 7 4 9.2 5.1 | 7.4 45.3 265 9 4 9.3 5.1
13500 8.8 47.8 255 7 4 9.1 5.0 | 8.8 47.8 270 8 4 9.4 5.2
13000 10.1 50.2 250 7 4 9.1 5.0 | 10.2 50.4 275 8 4 9.4 5.2
12500 11.5 52.7 245 7 4 8.8 4.8 | 11.6 52.9 280 8 4 9.3 5.1
12000 12.8 55.0 235 7 4 8.6 4.7 | 12.9 55.2 285 8 4 9.2 5.0
11500 14.0 57.2 230 8 4 8.3 4.6 | 14.3 57.7 290 8 4 9.1 5.0
11000 15.2 59.4 225 8 4 7.8 4.3 | 15.6 60.1 290 8 4 8.8 4.8
10500 16.4 61.5 220 8 4 5.1 2.8 | 17.0 62.6 295 7 4 6.0 3.3
10250 16.7 62.1 215 8 4 6.1 3.4 | 17.3 63.1 295 8 4 6.9 3.8
10000 17.4 63.3 215 7 4 10.4 5.7 | 18.1 64.6 300 7 4 11.2 6.1
9750 18.0 64.4 210 7 4 9.7 5.3 | 18.8 65.8 300 7 4 10.6 5.8
9500 18.7 65.7 210 6 3 8.3 4.6 | 19.6 67.3 300 6 3 8.7 4.8
9250 19.2 66.6 205 6 3 7.0 3.9 | 20.1 68.2 305 7 3 7.7 4.2
9000 19.8 67.6 205 6 3 8.7 4.8 | 20.8 69.4 305 6 3 10.0 5.5
8750 20.5 68.9 205 5 3 9.5 5.2 | 21.6 70.9 310 6 3 10.3 5.7
8500 21.2 70.2 205 5 3 7.9 4.3 | 22.3 72.1 310 6 3 9.5 5.2
8250 21.7 71.1 205 5 3 6.1 3.3 | 23.3 73.9 315 6 3 8.4 4.6
8000 22.1 71.8 205 5 3 6.7 3.7 | 23.6 74.5 320 6 3 10.0 5.5
7750 22.7 72.9 215 5 3 7.3 4.0 | 24.4 75.9 320 6 3 11.5 6.3
7500 23.2 73.8 230 5 3 5.3 2.9 | 25.2 77.4 320 6 3 9.6 5.3
7250 23.5 74.3 235 6 3 3.5 1.9 | 25.9 78.6 320 6 3 7.9 4.4
7000 23.8 74.8 240 6 3 4.8 2.6 | 26.5 79.7 325 6 3 9.8 5.4
6750 24.2 75.6 245 7 3 6.9 3.8 | 27.3 81.1 325 6 3 12.4 6.8
6500 24.8 76.6 250 7 3 6.4 3.5 | 28.2 82.8 325 5 3 11.4 6.2
6250 25.2 77.4 250 6 3 5.7 3.1 | 29.0 84.2 325 5 3 10.6 5.8
6000 25.6 78.1 250 6 3 4.9 2.7 | 29.8 85.6 330 6 3 9.5 5.2
5750 26.0 78.8 255 6 3 8.8 4.8 | 30.6 87.1 330 5 3 14.5 7.9
5500 27.1 80.8 255 5 2 19.2 10.5 | 32.2 90.0 330 5 3 28.8 15.8
08/10/2026 AT 1500 MDT | 08/10/2026 AT 1800 MDT
|
CAPE... +165.9 LI... -0.9 | CAPE... +279.0 LI... -1.3
CINH... -17.9 K INDEX... +27.7 | CINH... -62.5 K INDEX... +28.0
|
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 -65.3 -85.5 290 24 12 1.4 0.8 | -65.5 -85.9 290 22 11 0.3 0.2
45000 -61.0 -77.8 295 30 15 5.3 2.9 | -61.7 -79.1 290 27 14 6.4 3.5
40000 -52.4 -62.3 290 30 16 7.8 4.3 | -51.8 -61.2 290 29 15 7.6 4.2
38000 -47.8 -54.0 285 29 15 7.7 4.3 | -47.2 -53.0 285 31 16 7.6 4.1
36000 -43.1 -45.6 280 29 15 7.8 4.3 | -42.7 -44.9 285 33 17 7.8 4.3
34000 -38.4 -37.1 270 27 14 7.9 4.3 | -37.2 -35.0 280 30 15 8.1 4.4
32000 -33.1 -27.6 265 25 13 8.4 4.6 | -32.4 -26.3 275 28 14 8.3 4.6
30000 -28.3 -18.9 265 25 13 8.0 4.4 | -27.9 -18.2 275 27 14 7.6 4.2
29000 -26.0 -14.8 265 25 13 8.0 4.4 | -25.6 -14.1 275 26 14 7.7 4.2
28000 -23.7 -10.7 265 24 12 7.1 3.9 | -23.3 -9.9 275 26 13 7.4 4.1
27000 -21.6 -6.9 265 23 12 7.2 3.9 | -21.1 -6.0 280 25 13 7.4 4.1
26000 -19.5 -3.1 265 23 12 7.2 3.9 | -19.0 -2.2 280 24 12 7.5 4.1
25000 -17.4 0.7 265 22 11 6.8 3.7 | -16.8 1.8 285 23 12 6.9 3.8
24000 -15.4 4.3 265 21 11 6.6 3.6 | -14.9 5.2 285 22 11 6.5 3.6
23000 -13.5 7.7 265 20 10 6.7 3.7 | -13.0 8.6 290 20 10 6.5 3.6
22000 -11.6 11.1 260 19 10 6.9 3.8 | -11.1 12.0 290 19 10 6.7 3.7
21000 -9.5 14.9 265 18 9 7.1 3.9 | -9.1 15.6 300 17 9 6.8 3.7
20000 -7.5 18.5 270 18 9 7.1 3.9 | -7.2 19.0 305 15 8 6.9 3.8
19500 -6.5 20.3 275 17 9 7.1 3.9 | -5.7 21.7 315 14 7 6.7 3.7
19000 -4.9 23.2 275 17 9 7.3 4.0 | -4.8 23.4 320 13 7 6.7 3.7
18500 -3.8 25.2 280 17 9 7.3 4.0 | -3.8 25.2 320 12 6 6.7 3.7
18000 -2.7 27.1 280 16 8 7.9 4.3 | -2.8 27.0 325 11 6 7.6 4.2
17500 -1.6 29.1 285 15 8 7.8 4.3 | -1.7 28.9 330 10 5 7.5 4.1
17000 -0.4 31.3 285 14 7 8.4 4.6 | -0.5 31.1 330 10 5 8.2 4.5
16500 0.8 33.4 285 12 6 8.7 4.8 | 0.7 33.3 335 9 5 8.5 4.7
16000 2.1 35.8 285 11 6 8.8 4.8 | 2.0 35.6 335 8 4 8.7 4.8
15500 3.5 38.3 285 10 5 9.4 5.2 | 3.4 38.1 335 8 4 9.7 5.3
15000 4.9 40.8 285 9 5 9.4 5.2 | 4.8 40.6 340 8 4 9.6 5.3
14500 6.3 43.3 290 8 4 9.5 5.2 | 6.2 43.2 340 7 4 9.8 5.4
14000 7.7 45.9 290 8 4 9.5 5.2 | 7.7 45.9 340 7 4 9.8 5.4
13500 9.1 48.4 290 8 4 9.6 5.2 | 9.2 48.6 340 7 3 9.7 5.3
13000 10.6 51.1 295 7 4 9.6 5.3 | 10.6 51.1 340 6 3 9.7 5.3
12500 12.0 53.6 295 7 4 9.6 5.3 | 12.1 53.8 335 6 3 9.6 5.2
12000 13.4 56.1 295 6 3 9.6 5.3 | 13.5 56.3 335 5 3 9.5 5.2
11500 14.8 58.6 300 6 3 9.6 5.3 | 14.9 58.8 330 5 3 9.3 5.1
11000 16.3 61.3 300 6 3 9.4 5.2 | 16.2 61.2 325 4 2 8.9 4.9
10500 17.7 63.9 300 6 3 6.3 3.5 | 17.6 63.7 315 4 2 6.0 3.3
10250 18.1 64.6 300 6 3 7.4 4.0 | 17.9 64.2 310 4 2 6.5 3.6
10000 18.9 66.0 300 6 3 12.1 6.6 | 18.7 65.7 300 4 2 10.8 5.9
9750 19.7 67.5 300 5 3 11.4 6.2 | 19.4 66.9 290 3 2 9.9 5.4
9500 20.6 69.1 300 5 3 9.5 5.2 | 20.1 68.2 280 3 2 9.1 5.0
9250 21.2 70.2 300 6 3 8.4 4.6 | 20.7 69.3 270 4 2 7.9 4.3
9000 21.9 71.4 305 5 3 10.4 5.7 | 21.3 70.3 260 4 2 8.4 4.6
8750 22.7 72.9 305 5 3 10.6 5.8 | 22.0 71.6 250 4 2 8.7 4.8
8500 23.4 74.1 305 5 2 9.9 5.4 | 22.6 72.7 240 4 2 8.2 4.5
8250 24.1 75.4 305 5 3 8.8 4.8 | 23.1 73.6 230 4 2 7.4 4.1
8000 24.8 76.6 305 5 3 9.8 5.4 | 23.7 74.7 225 5 3 7.4 4.1
7750 25.6 78.1 305 5 2 11.0 6.0 | 24.2 75.6 215 5 3 7.7 4.2
7500 26.4 79.5 305 4 2 9.5 5.2 | 24.7 76.5 205 6 3 7.0 3.8
7250 27.0 80.6 305 5 2 7.9 4.3 | 25.2 77.4 205 6 3 6.1 3.3
7000 27.6 81.7 305 5 2 9.3 5.1 | 25.6 78.1 200 7 4 6.6 3.6
6750 28.4 83.1 305 4 2 11.7 6.4 | 26.1 79.0 195 7 4 7.6 4.2
6500 29.3 84.7 300 4 2 11.2 6.2 | 26.7 80.1 190 7 3 9.4 5.1
6250 30.1 86.2 300 4 2 10.6 5.8 | 27.4 81.3 190 7 4 10.6 5.8
6000 30.9 87.6 305 4 2 9.8 5.4 | 28.2 82.8 190 7 4 9.6 5.3
5750 31.6 88.9 300 4 2 12.4 6.8 | 28.9 84.0 185 7 4 11.0 6.0
5500 32.9 91.2 300 4 2 22.6 12.4 | 29.9 85.8 185 6 3 16.9 9.3
________________________________________________________________________________
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 NEAR THE OLD STAPLETON
AIRPORT SITE IN DENVER, COLORADO AT
NORTH LATITUDE: 39 DEG 46 MIN 5.016 SEC
WEST LONGITUDE: 104 DEG 52 MIN 9.984 SEC
ELEVATION: 5285 FEET (1611 METERS)
AND MAY NOT BE REPRESENTATIVE OF OTHER AREAS ALONG THE FRONT RANGE OF THE
COLORADO ROCKY MOUNTAINS. 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.
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