718
UXUS97 KBOU 150123
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
1822 MST SATURDAY, FEBRUARY 14, 2026
THIS FORECAST IS FOR SUNDAY, FEBRUARY 15, 2026:
IF THE TRIGGER TEMPERATURE OF 58.5 F/14.7 C IS REACHED...THEN
THERMAL SOARING INDEX....................... GOOD
MAXIMUM RATE OF LIFT........................ 407 FT/MIN (2.1 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 13284 FT MSL (8008 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 68.0 F/20.5 C
TIME OF TRIGGER TEMPERATURE.................... 1130 MST
TIME OF OVERDEVELOPMENT........................ NONE
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................. 10346 FT MSL (5071 FT AGL)
THERMAL SOARING OUTLOOK FOR MONDAY 02/16....... EXCELLENT
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1700 MST)......... TRENDING THE SAME
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1700 MST)................ WEAK NVA
POTENTIAL HEIGHT OF WAVE....................... 44927 FT MSL (39651 FT AGL)
WAVE SOARING OUTLOOK FOR MONDAY 02/16.......... FAIR
REMARKS...
SUNRISE/SUNSET.................... 06:51:31 / 17:35:39 MST
TOTAL POSSIBLE SUNSHINE........... 10 HR 44 MIN 8 SEC (644 MIN 8 SEC)
ALTITUDE OF SUN AT 12:13:35 MST... 37.66 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 02/15/2026 AT 0500 MST
FREEZING LEVEL.................. 11244 FT MSL (5968 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 18100 FT MSL (12824 FT AGL)
LIFTED CONDENSATION LEVEL....... 16874 FT MSL (11598 FT AGL)
LIFTED INDEX.................... +3.4
K INDEX......................... -6.9
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 -62.0 -79.6 270 61 31 1.2 0.7 M M M M M
45000 -60.1 -76.2 270 79 41 0.4 0.2 M M M M M
40000 -59.6 -75.3 275 82 42 0.3 0.2 M M M M M
38000 -58.0 -72.4 275 79 41 4.6 2.5 M M M M M
36000 -55.2 -67.4 275 73 38 4.6 2.5 M M M M M
34000 -52.1 -61.8 280 68 35 7.6 4.2 M M M M M
32000 -47.5 -53.5 280 64 33 7.6 4.2 M M M M M
30000 -42.2 -44.0 280 61 31 8.4 4.6 33.6 92.5 10.2 M M
29000 -39.7 -39.5 280 61 32 8.4 4.6 33.0 91.4 9.9 M M
28000 -37.2 -35.0 280 62 32 8.4 4.6 32.6 90.6 9.7 M M
27000 -34.7 -30.5 280 62 32 7.3 4.0 32.1 89.7 9.4 M M
26000 -32.5 -26.5 280 63 32 7.3 4.0 31.0 87.8 8.7 M M
25000 -30.3 -22.5 280 63 32 7.3 4.0 30.1 86.2 8.0 M M
24000 -28.1 -18.6 280 63 33 7.4 4.1 29.3 84.8 7.5 M M
23000 -25.9 -14.6 280 61 31 7.4 4.1 28.4 83.1 6.8 M M
22000 -23.6 -10.5 280 58 30 7.4 4.1 27.6 81.6 6.2 M M
21000 -21.4 -6.5 280 55 28 7.0 3.9 26.8 80.2 5.6 M M
20000 -19.3 -2.7 280 53 27 7.0 3.9 25.7 78.3 4.8 M M
19500 -18.3 -0.9 275 51 26 7.0 3.9 25.3 77.5 4.4 M M
19000 -17.2 1.0 275 50 26 7.0 3.9 24.8 76.7 4.1 M M
18500 -16.2 2.8 275 49 25 7.2 4.0 24.4 75.9 3.7 M M
18000 -15.1 4.8 275 47 24 7.3 4.0 24.0 75.1 3.4 M M
17500 -14.0 6.8 275 46 24 7.4 4.0 23.6 74.4 3.0 M M
17000 -12.9 8.8 275 44 23 7.7 4.2 23.2 73.7 2.7 M M
16500 -11.7 10.9 270 42 22 7.7 4.2 22.8 73.1 2.4 M M
16000 -10.6 12.9 270 40 21 7.4 4.0 22.5 72.4 2.1 M M
15500 -9.5 14.9 270 38 19 7.4 4.0 22.0 71.7 1.7 M M
15000 -7.8 18.0 270 34 17 7.3 4.0 21.4 70.6 1.2 M M
14500 -6.7 19.9 270 31 16 7.3 4.0 21.0 69.9 0.8 M M
14000 -5.6 21.9 270 28 14 7.3 4.0 20.6 69.2 0.5 M M
13500 -4.5 23.9 270 25 13 7.4 4.0 20.2 68.4 0.1 M M
13000 -3.5 25.7 270 22 11 7.1 3.9 19.8 67.7 -0.3 571 2.9
12500 -2.4 27.7 270 20 10 7.1 3.9 19.4 66.9 -0.7 525 2.7
12000 -1.4 29.5 265 17 9 6.7 3.7 19.0 66.1 -1.1 479 2.4
11500 -0.4 31.3 265 15 8 6.7 3.7 18.5 65.2 -1.6 434 2.2
11000 0.6 33.1 265 13 7 5.7 3.1 17.9 64.3 -2.1 391 2.0
10500 1.3 34.3 260 11 6 6.0 3.3 17.2 63.0 -2.9 354 1.8
10250 1.7 35.1 260 11 5 2.4 1.3 16.8 62.3 -3.2 335 1.7
10000 1.8 35.2 260 10 5 2.0 1.1 16.1 61.0 -3.9 326 1.7
9750 2.1 35.8 255 9 5 5.3 2.9 15.7 60.3 -4.3 309 1.6
9500 2.4 36.3 245 9 4 4.8 2.6 15.3 59.6 -4.7 291 1.5
9250 2.8 37.0 240 8 4 4.0 2.2 14.9 58.9 -5.1 274 1.4
9000 3.0 37.4 230 7 4 2.6 1.5 14.4 58.0 -5.7 260 1.3
8750 3.2 37.8 225 7 4 3.4 1.9 13.9 57.0 -6.2 247 1.3
8500 3.4 38.1 215 7 4 4.1 2.2 13.4 56.2 -6.7 232 1.2
8250 3.7 38.7 205 7 4 3.3 1.8 13.0 55.3 -7.2 217 1.1
8000 3.9 39.0 200 7 3 2.6 1.4 12.4 54.4 -7.8 204 1.0
7750 4.1 39.4 195 6 3 2.9 1.6 11.9 53.4 -8.3 190 1.0
7500 4.3 39.7 195 6 3 2.7 1.5 11.4 52.4 -8.9 177 0.9
7250 4.4 39.9 195 5 3 2.0 1.1 10.8 51.4 -9.5 165 0.8
7000 4.6 40.3 190 5 2 1.9 1.0 10.2 50.3 -10.1 153 0.8
6750 4.7 40.5 190 4 2 1.2 0.6 9.6 49.2 -10.7 142 0.7
6500 4.7 40.5 190 3 2 -0.8 -0.4 8.8 47.9 -11.5 134 0.7
6250 4.6 40.3 200 3 2 -1.8 -1.0 8.0 46.4 -12.3 130 0.7
6000 4.5 40.1 215 3 2 -0.4 -0.2 7.1 44.9 -13.2 126 0.6
5750 4.4 39.9 225 3 2 -5.1 -2.8 6.3 43.4 -14.1 122 0.6
5500 3.4 38.1 220 3 2 -20.6 -11.3 4.6 40.3 -15.8 144 0.7
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
02/15/2026 AT 0800 MST | 02/15/2026 AT 1100 MST
|
CAPE... 0.0 LI... +6.1 | CAPE... 0.0 LI... +6.1
CINH... 0.0 K INDEX... -13.6 | CINH... -0.1 K INDEX... -16.7
|
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 -61.8 -79.2 270 61 31 1.4 0.8 | -62.3 -80.1 265 64 33 1.4 0.8
45000 -59.6 -75.3 265 83 43 -0.2 -0.1 | -60.2 -76.4 265 86 44 -0.8 -0.4
40000 -60.0 -76.0 270 82 42 -0.3 -0.2 | -61.4 -78.5 270 78 40 -0.9 -0.5
38000 -58.5 -73.3 270 78 40 4.7 2.6 | -59.4 -74.9 270 74 38 6.0 3.3
36000 -55.7 -68.3 270 71 37 4.7 2.6 | -55.8 -68.4 270 67 35 6.0 3.3
34000 -52.4 -62.3 270 66 34 8.0 4.4 | -51.8 -61.2 270 63 32 8.0 4.4
32000 -47.0 -52.6 270 62 32 8.1 4.4 | -47.0 -52.6 270 61 32 8.1 4.4
30000 -42.1 -43.8 270 61 31 8.0 4.4 | -41.6 -42.9 265 60 31 8.1 4.4
29000 -39.7 -39.5 270 61 31 8.0 4.4 | -39.1 -38.4 265 60 31 8.1 4.4
28000 -37.3 -35.1 270 61 31 8.0 4.4 | -36.7 -34.1 265 60 31 8.1 4.5
27000 -35.0 -31.0 270 61 31 7.8 4.3 | -34.3 -29.7 265 59 31 7.6 4.1
26000 -32.6 -26.7 270 61 32 7.8 4.3 | -32.0 -25.6 265 59 30 7.6 4.2
25000 -30.3 -22.5 270 62 32 7.8 4.3 | -29.8 -21.6 265 59 30 7.6 4.2
24000 -27.9 -18.2 275 62 32 7.7 4.2 | -27.5 -17.5 265 59 30 7.6 4.2
23000 -25.6 -14.1 275 60 31 7.6 4.2 | -25.2 -13.4 265 58 30 7.6 4.2
22000 -23.4 -10.1 275 58 30 7.6 4.2 | -22.9 -9.2 265 58 30 7.6 4.2
21000 -21.1 -6.0 275 56 29 7.5 4.1 | -20.6 -5.1 270 57 29 7.8 4.3
20000 -18.8 -1.8 275 53 27 7.5 4.1 | -18.3 -0.9 270 55 28 7.8 4.3
19500 -17.7 0.1 275 52 27 7.5 4.1 | -17.2 1.0 270 54 28 7.8 4.3
19000 -16.6 2.1 275 50 26 7.5 4.1 | -16.0 3.2 270 53 27 7.8 4.3
18500 -15.5 4.1 270 49 25 7.4 4.1 | -14.8 5.4 270 52 27 7.7 4.2
18000 -14.4 6.1 270 48 25 7.4 4.1 | -13.7 7.3 270 50 26 7.7 4.2
17500 -13.3 8.1 270 47 24 7.4 4.0 | -12.5 9.5 270 49 25 7.6 4.2
17000 -11.6 11.1 270 45 23 7.2 3.9 | -11.4 11.5 270 48 25 7.3 4.0
16500 -10.6 12.9 270 44 23 7.1 3.9 | -10.3 13.5 270 47 24 7.3 4.0
16000 -9.5 14.9 270 42 22 7.0 3.8 | -8.7 16.3 270 45 23 7.1 3.9
15500 -8.5 16.7 270 41 21 7.0 3.8 | -7.6 18.3 270 43 22 7.1 3.9
15000 -7.5 18.5 270 39 20 6.8 3.8 | -6.6 20.1 270 41 21 6.3 3.5
14500 -6.4 20.5 270 37 19 6.9 3.8 | -5.7 21.7 270 39 20 6.4 3.5
14000 -5.4 22.3 265 35 18 6.7 3.7 | -4.7 23.5 270 36 19 6.7 3.7
13500 -4.4 24.1 265 32 17 6.7 3.7 | -3.7 25.3 270 34 18 6.7 3.7
13000 -3.4 25.9 265 29 15 6.7 3.7 | -2.7 27.1 270 32 16 6.7 3.7
12500 -2.4 27.7 265 27 14 6.7 3.7 | -1.7 28.9 265 29 15 6.7 3.7
12000 -1.4 29.5 265 24 12 6.8 3.7 | -0.7 30.7 265 27 14 6.6 3.6
11500 -0.4 31.3 265 21 11 6.9 3.8 | 0.2 32.4 265 24 12 6.6 3.6
11000 0.6 33.1 265 18 9 6.8 3.7 | 1.2 34.2 265 21 11 6.5 3.6
10500 1.6 34.9 260 16 8 7.5 4.1 | 2.1 35.8 265 17 9 7.4 4.1
10250 2.1 35.8 260 15 8 3.6 2.0 | 2.6 36.7 260 15 8 2.7 1.5
10000 2.2 36.0 260 14 7 4.1 2.2 | 2.7 36.9 260 13 7 4.2 2.3
9750 2.8 37.0 260 13 6 8.3 4.5 | 3.3 37.9 260 11 6 9.9 5.4
9500 3.3 37.9 260 11 6 7.5 4.1 | 4.0 39.2 255 10 5 8.8 4.9
9250 3.9 39.0 255 10 5 6.5 3.6 | 4.6 40.3 250 9 5 7.3 4.0
9000 4.3 39.7 255 9 5 4.6 2.5 | 5.1 41.2 240 6 3 5.8 3.2
8750 4.6 40.3 250 8 4 5.0 2.7 | 5.6 42.1 235 5 3 7.3 4.0
8500 5.0 41.0 250 7 4 5.7 3.1 | 6.2 43.2 230 5 3 8.1 4.4
8250 5.4 41.7 245 6 3 4.7 2.6 | 6.7 44.1 225 5 3 6.2 3.4
8000 5.7 42.3 240 6 3 3.6 2.0 | 7.1 44.8 205 4 2 4.3 2.4
7750 5.9 42.6 235 5 3 3.0 1.6 | 7.4 45.3 190 4 2 5.5 3.0
7500 6.1 43.0 230 5 3 2.4 1.3 | 7.8 46.0 195 4 2 5.5 3.0
7250 6.2 43.2 225 5 3 2.0 1.1 | 8.2 46.8 195 4 2 2.9 1.6
7000 6.3 43.3 220 5 2 1.9 1.0 | 8.3 46.9 185 4 2 1.1 0.6
6750 6.5 43.7 215 4 2 1.2 0.7 | 8.4 47.1 180 4 2 4.2 2.3
6500 6.4 43.5 210 6 3 -2.4 -1.3 | 8.8 47.8 185 4 2 5.8 3.2
6250 6.1 43.0 210 6 3 -5.1 -2.8 | 9.2 48.6 180 4 2 5.0 2.7
6000 5.7 42.3 210 6 3 -4.3 -2.4 | 9.5 49.1 180 3 2 3.9 2.1
5750 5.3 41.5 205 6 3 -6.9 -3.8 | 9.9 49.8 180 3 1 8.8 4.8
5500 4.4 39.9 205 6 3 -19.1 -10.5 | 11.0 51.8 180 2 1 21.5 11.8
02/15/2026 AT 1400 MST | 02/15/2026 AT 1700 MST
|
CAPE... 0.0 LI... +4.9 | CAPE... 0.0 LI... +4.8
CINH... 0.0 K INDEX... -13.2 | CINH... -0.3 K INDEX... -10.0
|
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 -62.8 -81.0 260 69 35 1.8 1.0 | -62.8 -81.0 260 72 37 2.1 1.1
45000 -60.1 -76.2 260 86 44 -1.7 -0.9 | -59.7 -75.5 260 86 44 0.8 0.4
40000 -62.5 -80.5 265 83 43 -1.7 -0.9 | -61.7 -79.1 265 91 47 -1.4 -0.7
38000 -60.2 -76.4 265 80 41 7.1 3.9 | -59.7 -75.5 265 89 46 6.4 3.5
36000 -55.9 -68.6 265 76 39 7.1 3.9 | -55.8 -68.4 265 84 43 6.4 3.5
34000 -51.4 -60.5 265 72 37 8.4 4.6 | -51.6 -60.9 265 79 41 8.8 4.8
32000 -46.3 -51.3 265 68 35 8.5 4.6 | -46.3 -51.3 265 75 39 8.9 4.9
30000 -41.3 -42.3 265 64 33 8.3 4.6 | -41.1 -42.0 265 71 36 8.2 4.5
29000 -38.2 -36.8 265 61 32 8.3 4.5 | -38.0 -36.4 260 68 35 8.2 4.5
28000 -35.7 -32.3 265 60 31 8.3 4.5 | -35.6 -32.1 260 66 34 8.2 4.5
27000 -33.2 -27.8 265 59 30 8.2 4.5 | -33.2 -27.8 260 64 33 7.0 3.8
26000 -30.8 -23.4 260 60 31 8.2 4.5 | -31.1 -24.0 260 63 32 7.1 3.9
25000 -28.3 -18.9 260 62 32 8.2 4.5 | -29.0 -20.2 260 61 31 7.1 3.9
24000 -25.9 -14.6 260 63 33 6.6 3.6 | -26.8 -16.2 255 59 30 7.3 4.0
23000 -24.1 -11.4 260 62 32 6.1 3.3 | -24.6 -12.3 255 55 28 7.4 4.1
22000 -22.3 -8.1 260 61 31 6.1 3.3 | -22.4 -8.3 255 51 26 7.4 4.1
21000 -20.4 -4.7 260 60 31 7.5 4.1 | -20.2 -4.4 255 48 25 7.0 3.8
20000 -18.1 -0.6 260 57 29 7.4 4.1 | -18.1 -0.6 255 48 25 7.0 3.9
19500 -17.0 1.4 265 56 29 7.4 4.1 | -17.0 1.4 255 48 25 7.0 3.9
19000 -15.9 3.4 265 55 28 7.4 4.1 | -16.0 3.2 260 48 25 7.1 3.9
18500 -14.8 5.4 265 54 28 7.7 4.2 | -15.0 5.0 260 47 24 6.5 3.5
18000 -13.6 7.5 265 52 27 7.8 4.3 | -14.0 6.8 260 47 24 6.3 3.5
17500 -12.4 9.7 265 51 26 7.7 4.3 | -13.1 8.4 260 47 24 6.4 3.5
17000 -11.3 11.7 265 50 26 7.5 4.1 | -12.0 10.4 260 46 24 7.5 4.1
16500 -10.1 13.8 265 49 25 7.6 4.2 | -10.9 12.4 265 45 23 7.4 4.1
16000 -9.0 15.8 265 48 25 7.1 3.9 | -9.7 14.5 265 44 23 8.0 4.4
15500 -8.0 17.6 265 45 23 7.1 3.9 | -8.5 16.7 265 43 22 8.1 4.4
15000 -6.9 19.6 265 43 22 7.3 4.0 | -7.3 18.9 260 42 21 8.0 4.4
14500 -5.8 21.6 265 41 21 7.4 4.1 | -6.1 21.0 260 39 20 7.9 4.3
14000 -4.7 23.5 265 39 20 7.5 4.1 | -4.4 24.1 260 36 18 7.4 4.1
13500 -3.0 26.6 265 36 18 7.6 4.2 | -3.3 26.1 260 33 17 7.4 4.0
13000 -1.9 28.6 260 34 17 7.4 4.0 | -2.2 28.0 255 30 16 7.7 4.2
12500 -0.8 30.6 260 31 16 7.3 4.0 | -1.0 30.2 255 27 14 7.8 4.3
12000 0.3 32.5 260 29 15 7.4 4.1 | 0.1 32.2 255 24 13 7.8 4.3
11500 1.4 34.5 260 26 13 7.4 4.1 | 1.3 34.3 255 21 11 7.8 4.3
11000 2.4 36.3 255 22 11 6.0 3.3 | 2.4 36.3 250 18 9 6.8 3.7
10500 3.2 37.8 255 19 10 4.4 2.4 | 3.3 37.9 250 15 8 5.2 2.8
10250 3.6 38.5 255 17 9 8.9 4.9 | 3.8 38.8 250 14 7 10.4 5.7
10000 4.4 39.9 250 14 7 9.9 5.4 | 4.8 40.6 245 12 6 11.5 6.3
9750 4.9 40.8 250 12 6 5.8 3.2 | 5.4 41.7 245 11 6 6.7 3.7
9500 5.4 41.7 245 10 5 7.5 4.1 | 6.0 42.8 245 10 5 8.8 4.8
9250 6.0 42.8 240 9 4 4.9 2.7 | 6.5 43.7 245 8 4 5.2 2.9
9000 6.3 43.3 235 7 4 5.4 3.0 | 6.8 44.2 240 7 4 5.0 2.7
8750 6.8 44.2 230 6 3 8.3 4.6 | 7.4 45.3 240 6 3 8.2 4.5
8500 7.4 45.3 220 5 2 8.4 4.6 | 7.9 46.2 245 4 2 8.1 4.4
8250 8.0 46.4 205 4 2 7.0 3.8 | 8.5 47.3 245 2 1 6.8 3.8
8000 8.5 47.3 190 3 1 5.7 3.1 | 9.0 48.2 260 1 1 5.5 3.0
7750 8.9 48.0 170 2 1 7.3 4.0 | 9.4 48.9 355 1 0 6.8 3.7
7500 9.5 49.1 135 2 1 8.0 4.4 | 9.9 49.8 040 2 1 7.5 4.1
7250 10.1 50.2 110 2 1 6.7 3.7 | 10.5 50.9 045 4 2 6.8 3.7
7000 10.5 50.9 105 3 1 5.8 3.2 | 10.9 51.6 045 4 2 6.2 3.4
6750 11.0 51.8 100 3 2 8.6 4.7 | 11.5 52.7 045 5 2 8.3 4.6
6500 11.7 53.1 090 3 2 9.9 5.4 | 12.1 53.8 045 6 3 9.1 5.0
6250 12.4 54.3 085 4 2 8.8 4.8 | 12.7 54.9 045 7 3 7.8 4.3
6000 13.1 55.6 085 3 2 8.2 4.5 | 13.3 55.9 040 7 3 7.2 4.0
5750 13.7 56.7 080 3 2 11.3 6.2 | 13.9 57.0 040 7 3 8.6 4.7
5500 14.8 58.6 080 3 2 18.5 10.2 | 14.5 58.1 030 6 3 6.8 3.7
________________________________________________________________________________
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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