851
UXUS97 KBOU 061309
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
0707 MDT WEDNESDAY, AUGUST 6, 2025
THIS FORECAST IS FOR WEDNESDAY, AUGUST 6, 2025:
IF THE TRIGGER TEMPERATURE OF 89.4 F/31.9 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1615 FT/MIN (8.2 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 21621 FT MSL (16300 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 98.0 F/37.1 C
TIME OF TRIGGER TEMPERATURE.................... 1030 MDT
TIME OF OVERDEVELOPMENT........................ 1600 MDT
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... NONE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 15511 FT MSL (10190 FT AGL)
THERMAL SOARING OUTLOOK FOR THURSDAY 08/07..... EXCELLENT
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1800 MDT)......... LITTLE CHANGE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1800 MDT)................ NEITHER
POTENTIAL HEIGHT OF WAVE....................... 35026 FT MSL (29705 FT AGL)
WAVE SOARING OUTLOOK FOR THURSDAY 08/07........ POOR
REMARKS... HOT, DRY, AND SMOKY TODAY WITH AN ISOLATED GUSTY SHOWER THIS
AFTERNOON
SUNRISE/SUNSET.................... 06:03:43 / 20:06:57 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 3 MIN 15 SEC (843 MIN 15 SEC)
ALTITUDE OF SUN AT 13:05:20 MDT... 66.67 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 08/06/2025 AT 0600 MDT
FREEZING LEVEL.................. 16572 FT MSL (11251 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 24781 FT MSL (19460 FT AGL)
LIFTED CONDENSATION LEVEL....... 24009 FT MSL (18688 FT AGL)
LIFTED INDEX.................... +1.6
K INDEX......................... -1.2
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 -63.6 -82.5 260 35 18 0.1 0.0 M M M M M
45000 -61.4 -78.5 260 56 29 4.7 2.6 M M M M M
40000 -53.6 -64.5 270 55 29 6.9 3.8 M M M M M
38000 -49.5 -57.1 270 52 27 6.8 3.8 M M M M M
36000 -45.4 -49.7 270 48 25 7.1 3.9 M M M M M
34000 -40.8 -41.4 270 44 23 7.8 4.3 M M M M M
32000 -36.1 -33.0 270 41 21 8.3 4.6 M M M M M
30000 -31.6 -24.9 270 37 19 7.6 4.2 44.1 111.3 5.6 M M
29000 -28.7 -19.7 270 34 18 7.6 4.2 43.1 109.6 4.9 M M
28000 -26.5 -15.7 275 32 17 7.6 4.1 42.3 108.2 4.3 M M
27000 -24.2 -11.6 275 30 16 7.6 4.2 41.4 106.6 3.7 M M
26000 -22.0 -7.6 275 28 15 7.6 4.2 40.6 105.1 3.1 M M
25000 -19.7 -3.5 275 26 14 7.3 4.0 39.9 103.8 2.5 M M
24000 -17.5 0.5 275 25 13 7.3 4.0 38.9 102.0 1.7 M M
23000 -15.4 4.3 275 23 12 7.3 4.0 38.0 100.4 1.0 M M
22000 -13.2 8.2 275 21 11 7.4 4.1 37.2 99.0 0.3 M M
21000 -11.0 12.2 275 20 11 7.4 4.1 36.3 97.4 -0.5 1558 7.9
20000 -8.8 16.2 275 20 10 7.5 4.1 35.5 96.0 -1.2 1463 7.4
19500 -7.7 18.1 275 20 10 7.7 4.2 35.2 95.3 -1.5 1415 7.2
19000 -6.5 20.3 275 19 10 8.2 4.5 34.9 94.8 -1.7 1364 6.9
18500 -5.2 22.6 275 18 9 8.2 4.5 34.6 94.3 -2.0 1312 6.7
18000 -4.0 24.8 275 18 9 8.5 4.7 34.4 93.9 -2.2 1260 6.4
17500 -2.7 27.1 280 17 9 8.5 4.7 34.2 93.5 -2.4 1207 6.1
17000 -1.4 29.5 285 17 8 8.7 4.8 34.0 93.2 -2.6 1154 5.9
16500 -0.1 31.8 285 16 8 9.0 4.9 33.8 92.9 -2.7 1099 5.6
16000 1.2 34.2 290 15 8 9.0 4.9 33.7 92.7 -2.9 1044 5.3
15500 3.3 37.9 295 15 8 9.2 5.1 33.6 92.4 -3.0 961 4.9
15000 4.6 40.3 295 16 8 9.2 5.1 33.5 92.3 -3.1 905 4.6
14500 6.0 42.8 295 16 8 9.3 5.1 33.4 92.1 -3.2 849 4.3
14000 7.4 45.3 300 17 9 9.3 5.1 33.3 92.0 -3.3 793 4.0
13500 8.7 47.7 300 17 9 9.2 5.0 33.2 91.8 -3.5 738 3.7
13000 10.1 50.2 300 18 9 9.2 5.0 33.1 91.7 -3.6 682 3.5
12500 11.5 52.7 300 18 10 9.3 5.1 33.1 91.5 -3.7 626 3.2
12000 12.9 55.2 300 19 10 9.4 5.1 33.0 91.4 -3.8 570 2.9
11500 14.2 57.6 300 19 10 9.2 5.0 32.9 91.3 -3.9 514 2.6
11000 15.6 60.1 300 19 10 9.2 5.0 32.8 91.1 -4.0 459 2.3
10500 16.8 62.2 300 19 10 4.1 2.3 32.6 90.6 -4.3 408 2.1
10250 17.1 62.8 300 19 10 7.4 4.1 32.1 89.8 -4.7 392 2.0
10000 17.9 64.2 300 19 10 12.8 7.0 32.3 90.1 -4.6 358 1.8
9750 18.8 65.8 300 19 10 11.2 6.2 32.4 90.3 -4.5 325 1.7
9500 19.6 67.3 305 18 10 8.0 4.4 32.4 90.4 -4.4 295 1.5
9250 20.0 68.0 305 18 9 6.6 3.6 32.2 89.9 -4.7 273 1.4
9000 20.7 69.3 305 18 9 10.0 5.5 32.1 89.7 -4.8 247 1.3
8750 21.5 70.7 305 18 9 10.4 5.7 32.1 89.9 -4.8 216 1.1
8500 22.2 72.0 305 17 9 8.3 4.5 32.1 89.8 -4.8 188 1.0
8250 22.7 72.9 305 18 9 6.9 3.8 31.9 89.5 -5.0 164 0.8
8000 23.3 73.9 305 18 9 8.4 4.6 31.8 89.2 -5.2 140 0.7
7750 23.9 75.0 305 17 9 8.4 4.6 31.7 89.0 -5.2 112 0.6
7500 24.5 76.1 305 16 8 6.2 3.4 31.5 88.7 -5.4 89 0.5
7250 24.9 76.8 305 17 9 5.1 2.8 31.2 88.1 -5.8 69 0.3
7000 25.3 77.5 305 17 9 7.0 3.8 30.9 87.5 -6.1 49 0.2
6750 25.8 78.4 300 16 8 3.8 2.1 30.6 87.1 -6.3 27 0.1
6500 25.8 78.4 295 14 7 -1.7 -0.9 29.9 85.8 -7.1 19 0.1
6250 25.7 78.3 290 13 7 -0.4 -0.2 29.1 84.3 -7.9 15 0.1
6000 25.6 78.1 285 12 6 -4.5 -2.4 28.2 82.8 -8.8 11 0.1
5750 24.6 76.3 275 10 5 -24.6 -13.5 26.5 79.7 -10.5 33 0.2
5500 21.9 71.4 255 6 3 -45.6 -25.0 23.0 73.5 -14.0 108 0.6
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
08/06/2025 AT 0900 MDT | 08/06/2025 AT 1200 MDT
|
CAPE... 0.0 LI... +1.4 | CAPE... +27.3 LI... +1.1
CINH... -0.2 K INDEX... +12.0 | CINH... -31.7 K INDEX... +17.7
|
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 -63.9 -83.0 260 33 17 0.3 0.2 | -63.9 -83.0 265 33 17 0.8 0.4
45000 -61.5 -78.7 260 58 30 4.8 2.6 | -60.9 -77.6 270 57 30 4.1 2.3
40000 -53.6 -64.5 265 57 29 6.6 3.6 | -54.1 -65.4 270 60 31 7.0 3.8
38000 -49.6 -57.3 265 53 27 6.6 3.6 | -49.9 -57.8 270 55 28 6.9 3.8
36000 -45.7 -50.3 265 49 25 6.9 3.8 | -45.8 -50.4 265 51 26 7.2 3.9
34000 -41.0 -41.8 265 46 24 7.9 4.3 | -41.0 -41.8 265 47 24 7.9 4.4
32000 -36.2 -33.2 265 43 22 8.4 4.6 | -36.3 -33.3 265 43 22 8.4 4.6
30000 -31.4 -24.5 265 36 18 7.1 3.9 | -31.5 -24.7 260 36 19 7.0 3.8
29000 -29.3 -20.7 265 32 17 7.1 3.9 | -29.5 -21.1 260 33 17 7.0 3.8
28000 -27.2 -17.0 265 30 15 7.5 4.1 | -27.4 -17.3 260 30 16 7.1 3.9
27000 -25.0 -13.0 265 28 14 7.5 4.1 | -25.3 -13.5 260 28 14 7.1 3.9
26000 -22.7 -8.9 265 26 14 7.5 4.1 | -23.1 -9.6 260 26 13 7.1 3.9
25000 -20.5 -4.9 265 25 13 7.5 4.1 | -21.0 -5.8 260 24 12 7.8 4.3
24000 -18.3 -0.9 265 24 12 7.5 4.1 | -18.6 -1.5 260 23 12 7.9 4.4
23000 -16.1 3.0 265 23 12 7.5 4.1 | -16.3 2.7 265 22 11 8.0 4.4
22000 -13.9 7.0 270 22 11 7.7 4.2 | -13.9 7.0 265 22 11 8.1 4.4
21000 -11.6 11.1 270 20 10 7.7 4.2 | -11.5 11.3 270 22 11 8.1 4.4
20000 -9.3 15.3 275 19 10 7.7 4.2 | -9.2 15.4 270 23 12 8.1 4.5
19500 -8.2 17.2 275 18 9 8.0 4.4 | -8.0 17.6 270 23 12 8.2 4.5
19000 -7.0 19.4 275 17 9 8.3 4.6 | -6.8 19.8 270 23 12 8.3 4.6
18500 -5.7 21.7 280 17 9 8.3 4.6 | -5.5 22.1 270 23 12 8.3 4.5
18000 -4.5 23.9 280 16 8 8.8 4.8 | -4.3 24.3 270 22 11 9.0 5.0
17500 -3.2 26.2 285 16 8 8.8 4.8 | -2.9 26.8 275 22 11 9.0 4.9
17000 -1.9 28.6 285 16 8 8.9 4.9 | -1.6 29.1 275 21 11 8.9 4.9
16500 -0.5 31.1 290 16 8 9.1 5.0 | -0.3 31.5 275 21 11 8.8 4.9
16000 1.5 34.7 290 16 8 9.1 5.0 | 1.7 35.1 275 20 10 9.1 5.0
15500 2.8 37.0 290 17 9 9.1 5.0 | 3.1 37.6 275 20 10 9.3 5.1
15000 4.2 39.6 290 17 9 9.1 5.0 | 4.4 39.9 280 19 10 9.2 5.1
14500 5.5 41.9 295 18 9 9.0 5.0 | 5.8 42.4 280 19 10 9.1 5.0
14000 6.9 44.4 295 18 9 9.0 5.0 | 7.1 44.8 280 18 9 9.1 5.0
13500 8.2 46.8 295 18 9 9.2 5.0 | 8.5 47.3 280 17 9 9.3 5.1
13000 9.6 49.3 295 18 9 9.2 5.0 | 9.9 49.8 280 16 8 9.3 5.1
12500 11.0 51.8 295 18 9 9.0 5.0 | 11.3 52.3 280 15 8 9.3 5.1
12000 12.3 54.1 295 18 9 9.0 5.0 | 12.7 54.9 280 14 7 9.3 5.1
11500 13.7 56.7 300 18 9 9.2 5.0 | 14.0 57.2 280 13 7 9.3 5.1
11000 15.1 59.2 300 18 9 9.5 5.2 | 15.4 59.7 280 12 6 9.7 5.3
10500 16.2 61.2 300 18 9 3.8 2.1 | 16.5 61.7 280 11 6 4.4 2.4
10250 16.6 61.9 300 17 9 8.4 4.6 | 17.0 62.6 280 10 5 9.4 5.2
10000 17.5 63.5 300 17 9 13.4 7.4 | 17.9 64.2 280 10 5 13.6 7.5
9750 18.4 65.1 300 17 9 10.9 6.0 | 18.8 65.8 280 9 5 11.2 6.1
9500 19.1 66.4 300 16 8 7.4 4.1 | 19.5 67.1 280 9 5 7.4 4.1
9250 19.6 67.3 300 16 8 7.1 3.9 | 20.0 68.0 285 8 4 8.0 4.4
9000 20.3 68.5 300 16 8 10.8 5.9 | 20.8 69.4 285 8 4 12.6 6.9
8750 21.1 70.0 300 16 8 10.3 5.7 | 21.8 71.2 285 8 4 11.6 6.4
8500 21.8 71.2 300 16 8 7.6 4.2 | 22.5 72.5 285 7 4 8.7 4.7
8250 22.3 72.1 300 16 8 6.4 3.5 | 23.1 73.6 285 7 4 7.0 3.9
8000 22.9 73.2 300 16 8 9.3 5.1 | 23.7 74.7 285 7 4 11.4 6.3
7750 23.6 74.5 295 15 8 8.8 4.8 | 24.7 76.5 285 6 3 12.1 6.6
7500 24.1 75.4 295 15 8 5.4 3.0 | 25.4 77.7 285 6 3 8.2 4.5
7250 24.5 76.1 295 14 7 4.9 2.7 | 26.0 78.8 285 6 3 7.2 3.9
7000 24.9 76.8 295 14 7 7.6 4.1 | 26.6 79.9 290 6 3 12.5 6.8
6750 25.5 77.9 295 12 6 6.5 3.6 | 27.8 82.0 285 5 3 13.8 7.6
6500 25.8 78.4 290 11 6 2.7 1.5 | 28.6 83.5 285 5 3 9.1 5.0
6250 26.1 79.0 285 10 5 4.5 2.5 | 29.3 84.7 290 5 2 10.7 5.9
6000 26.3 79.3 280 9 5 1.2 0.7 | 30.1 86.2 290 4 2 9.0 4.9
5750 26.3 79.3 275 7 4 2.8 1.6 | 30.8 87.4 295 4 2 14.9 8.2
5500 27.0 80.6 260 5 3 14.3 7.8 | 32.5 90.5 295 4 2 28.6 15.7
08/06/2025 AT 1500 MDT | 08/06/2025 AT 1800 MDT
|
CAPE... +88.2 LI... +0.2 | CAPE... +108.0 LI... -0.0
CINH... -26.2 K INDEX... +19.3 | CINH... -37.7 K INDEX... +20.1
|
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 -64.2 -83.6 270 33 17 1.4 0.8 | -64.7 -84.5 275 34 17 0.8 0.5
45000 -60.6 -77.1 275 55 28 4.0 2.2 | -61.4 -78.5 275 52 27 4.5 2.5
40000 -53.9 -65.0 275 61 31 6.9 3.8 | -53.9 -65.0 275 56 29 7.2 3.9
38000 -49.8 -57.6 270 57 29 6.9 3.8 | -49.6 -57.3 275 53 27 7.2 3.9
36000 -45.7 -50.3 270 53 27 7.2 4.0 | -45.3 -49.5 270 49 25 7.7 4.2
34000 -40.9 -41.6 270 48 25 8.0 4.4 | -40.3 -40.5 270 46 24 8.4 4.6
32000 -35.5 -31.9 265 44 23 8.2 4.5 | -35.3 -31.5 265 43 22 8.9 4.9
30000 -31.1 -24.0 260 38 19 7.4 4.0 | -30.2 -22.4 260 39 20 7.5 4.1
29000 -28.9 -20.0 260 35 18 7.4 4.0 | -27.9 -18.2 260 37 19 7.5 4.1
28000 -26.7 -16.1 260 32 17 7.1 3.9 | -25.7 -14.3 255 35 18 7.2 4.0
27000 -24.6 -12.3 260 30 16 7.1 3.9 | -23.6 -10.5 255 32 16 7.3 4.0
26000 -22.5 -8.5 260 29 15 7.1 3.9 | -21.4 -6.5 260 29 15 7.3 4.0
25000 -20.4 -4.7 260 27 14 7.6 4.2 | -19.3 -2.7 260 26 14 6.9 3.8
24000 -18.1 -0.6 260 27 14 7.7 4.2 | -17.3 0.9 265 25 13 6.9 3.8
23000 -15.8 3.6 260 27 14 7.7 4.2 | -15.3 4.5 270 24 12 6.9 3.8
22000 -13.6 7.5 265 26 14 8.4 4.6 | -13.2 8.2 275 23 12 8.3 4.5
21000 -11.1 12.0 265 25 13 8.4 4.6 | -10.7 12.7 275 23 12 8.3 4.5
20000 -8.7 16.3 265 25 13 8.5 4.6 | -8.3 17.1 280 22 12 8.3 4.6
19500 -7.4 18.7 265 24 13 8.7 4.8 | -7.1 19.2 280 22 11 8.8 4.8
19000 -6.1 21.0 265 23 12 8.9 4.9 | -5.7 21.7 280 22 11 9.3 5.1
18500 -4.8 23.4 265 23 12 8.8 4.8 | -4.3 24.3 280 21 11 9.3 5.1
18000 -3.5 25.7 265 22 11 9.3 5.1 | -2.9 26.8 280 21 11 9.6 5.3
17500 -2.1 28.2 265 21 11 9.2 5.1 | -1.5 29.3 280 20 10 9.6 5.2
17000 -0.0 32.0 265 20 10 9.5 5.2 | -0.1 31.8 280 19 10 9.5 5.2
16500 1.4 34.5 265 19 10 9.5 5.2 | 2.0 35.6 280 18 9 9.3 5.1
16000 2.8 37.0 265 18 9 9.3 5.1 | 3.4 38.1 280 17 9 9.2 5.1
15500 4.2 39.6 265 17 9 9.3 5.1 | 4.8 40.6 275 17 9 9.1 5.0
15000 5.6 42.1 265 16 8 9.3 5.1 | 6.1 43.0 275 16 8 9.1 5.0
14500 6.9 44.4 265 15 8 9.2 5.0 | 7.5 45.5 270 15 8 9.2 5.0
14000 8.3 46.9 265 14 7 9.2 5.0 | 8.8 47.8 270 15 8 9.2 5.0
13500 9.7 49.5 265 13 7 9.4 5.2 | 10.2 50.4 265 14 7 9.2 5.0
13000 11.1 52.0 265 12 6 9.4 5.2 | 11.6 52.9 260 14 7 9.2 5.0
12500 12.5 54.5 265 11 6 9.3 5.1 | 12.9 55.2 255 13 7 9.2 5.0
12000 13.9 57.0 265 10 5 9.3 5.1 | 14.3 57.7 250 13 7 9.2 5.0
11500 15.3 59.5 265 9 5 9.7 5.3 | 15.6 60.1 245 13 7 9.3 5.1
11000 16.7 62.1 265 9 5 10.2 5.6 | 17.0 62.6 240 12 6 9.7 5.3
10500 17.9 64.2 265 8 4 4.3 2.3 | 18.1 64.6 235 12 6 4.4 2.4
10250 18.3 64.9 265 8 4 9.3 5.1 | 18.5 65.3 235 12 6 8.8 4.8
10000 19.2 66.6 265 8 4 13.3 7.3 | 19.4 66.9 230 12 6 12.8 7.0
9750 20.2 68.4 265 8 4 11.5 6.3 | 20.3 68.5 230 12 6 11.3 6.2
9500 20.9 69.6 265 7 4 7.7 4.2 | 21.0 69.8 225 12 6 7.4 4.1
9250 21.4 70.5 265 7 4 7.9 4.3 | 21.5 70.7 225 11 6 7.3 4.0
9000 22.2 72.0 265 7 4 11.7 6.4 | 22.2 72.0 220 11 6 11.3 6.2
8750 23.1 73.6 265 7 3 11.1 6.1 | 23.1 73.6 220 12 6 10.9 6.0
8500 23.8 74.8 265 6 3 9.0 4.9 | 23.8 74.8 215 12 6 8.8 4.8
8250 24.4 75.9 265 6 3 7.6 4.2 | 24.4 75.9 215 11 6 7.3 4.0
8000 25.0 77.0 265 6 3 10.8 5.9 | 25.0 77.0 210 11 6 10.2 5.6
7750 26.0 78.8 260 6 3 11.5 6.3 | 25.9 78.6 210 11 6 11.1 6.1
7500 26.7 80.1 260 6 3 8.7 4.7 | 26.6 79.9 205 12 6 8.5 4.6
7250 27.3 81.1 260 6 3 7.5 4.1 | 27.2 81.0 205 11 6 7.2 4.0
7000 27.9 82.2 260 6 3 11.3 6.2 | 27.7 81.9 200 11 6 10.4 5.7
6750 28.9 84.0 255 5 3 12.9 7.1 | 28.7 83.7 200 11 6 12.3 6.8
6500 29.7 85.5 250 5 2 9.9 5.4 | 29.5 85.1 200 11 6 9.9 5.4
6250 30.5 86.9 250 4 2 10.5 5.8 | 30.2 86.4 200 11 6 10.2 5.6
6000 31.3 88.3 250 4 2 9.8 5.4 | 30.9 87.6 200 11 5 8.6 4.7
5750 32.1 89.8 255 5 2 15.7 8.6 | 31.6 88.9 190 10 5 10.4 5.7
5500 33.7 92.7 255 4 2 26.9 14.8 | 32.6 90.7 190 9 5 18.3 10.0
________________________________________________________________________________
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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