482
UXUS97 KBOU 200044
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
1843 MDT THURSDAY, MARCH 19, 2026
THIS FORECAST IS FOR FRIDAY, MARCH 20, 2026:
IF THE TRIGGER TEMPERATURE OF 76.1 F/24.5 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1026 FT/MIN (5.2 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 16821 FT MSL (11395 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 85.0 F/29.9 C
TIME OF TRIGGER TEMPERATURE.................... 1115 MDT
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................. 12035 FT MSL (6609 FT AGL)
THERMAL SOARING OUTLOOK FOR SATURDAY 03/21..... EXCELLENT
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1800 MDT)......... NO CHANGE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1800 MDT)................ NEITHER
POTENTIAL HEIGHT OF WAVE....................... 28008 FT MSL (22582 FT AGL)
WAVE SOARING OUTLOOK FOR SATURDAY 03/21........ FAIR
REMARKS...
SUNRISE/SUNSET.................... 07:02:15 / 19:11:24 MDT
TOTAL POSSIBLE SUNSHINE........... 12 HR 9 MIN 9 SEC (729 MIN 9 SEC)
ALTITUDE OF SUN AT 13:06:49 MDT... 50.27 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 03/20/2026 AT 0600 MDT
FREEZING LEVEL.................. 14833 FT MSL (9407 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 21764 FT MSL (16338 FT AGL)
LIFTED CONDENSATION LEVEL....... 20877 FT MSL (15451 FT AGL)
LIFTED INDEX.................... +2.0
K INDEX......................... -8.9
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 -66.6 -87.9 315 42 22 2.9 1.6 82.8 181.1 31.0 M M
45000 -62.2 -80.0 315 45 23 2.5 1.4 65.8 150.5 22.7 M M
40000 -58.3 -72.9 310 45 23 6.3 3.4 49.7 121.4 13.5 M M
38000 -54.0 -65.2 310 41 21 7.3 4.0 47.1 116.7 12.1 M M
36000 -49.6 -57.3 305 37 19 7.3 4.0 45.2 113.3 11.0 M M
34000 -44.5 -48.1 305 38 19 7.7 4.2 43.0 109.4 9.8 M M
32000 -39.9 -39.8 310 40 21 7.7 4.2 41.5 106.7 8.9 M M
30000 -35.3 -31.5 310 44 23 7.8 4.3 39.8 103.7 7.9 M M
29000 -33.0 -27.4 310 47 24 7.8 4.3 39.1 102.3 7.4 M M
28000 -30.7 -23.3 310 50 26 7.7 4.2 38.4 101.2 7.0 M M
27000 -28.5 -19.3 315 49 25 7.4 4.0 37.5 99.4 6.3 M M
26000 -26.3 -15.3 315 48 25 7.4 4.1 36.5 97.8 5.6 M M
25000 -24.0 -11.2 315 47 24 7.4 4.1 35.8 96.4 5.0 M M
24000 -21.9 -7.4 315 45 23 7.0 3.9 34.8 94.6 4.3 M M
23000 -19.8 -3.6 315 43 22 7.0 3.9 33.7 92.7 3.5 M M
22000 -17.7 0.1 315 40 21 6.9 3.8 32.8 91.1 2.7 M M
21000 -14.8 5.4 315 38 19 8.0 4.4 31.9 89.5 2.0 M M
20000 -12.4 9.7 315 36 18 8.0 4.4 31.3 88.4 1.5 M M
19500 -11.2 11.8 315 35 18 8.0 4.4 31.1 88.0 1.3 M M
19000 -10.0 14.0 315 34 17 8.1 4.4 30.8 87.5 1.1 M M
18500 -8.8 16.2 315 33 17 8.1 4.4 30.5 86.9 0.8 M M
18000 -7.6 18.3 320 32 16 8.0 4.4 30.2 86.4 0.6 M M
17500 -6.4 20.5 320 31 16 8.0 4.4 29.9 85.9 0.3 M M
17000 -5.2 22.6 320 30 15 8.0 4.4 29.6 85.3 0.1 M M
16500 -4.0 24.8 325 29 15 8.0 4.4 29.3 84.8 -0.2 990 5.0
16000 -2.8 27.0 325 28 14 8.0 4.4 29.0 84.3 -0.5 939 4.8
15500 -1.6 29.1 325 27 14 8.1 4.4 28.8 83.8 -0.7 889 4.5
15000 -0.4 31.3 325 26 13 8.1 4.4 28.5 83.2 -1.0 838 4.3
14500 0.8 33.4 325 25 13 7.8 4.3 28.2 82.8 -1.2 787 4.0
14000 1.9 35.4 325 23 12 7.7 4.2 27.8 82.1 -1.6 739 3.8
13500 3.1 37.6 325 22 11 7.7 4.2 27.5 81.5 -1.9 690 3.5
13000 4.2 39.6 325 22 11 7.6 4.2 27.2 80.9 -2.3 641 3.3
12500 5.3 41.5 320 21 11 7.6 4.2 26.8 80.3 -2.6 593 3.0
12000 6.4 43.5 315 21 11 7.5 4.1 26.5 79.6 -3.0 545 2.8
11500 7.5 45.5 315 21 11 7.5 4.1 26.1 79.0 -3.4 498 2.5
11000 8.6 47.5 310 20 11 7.6 4.2 25.8 78.4 -3.7 450 2.3
10500 9.7 49.5 305 19 10 7.3 4.0 25.4 77.8 -4.1 402 2.0
10250 10.2 50.4 300 19 10 7.6 4.2 25.2 77.4 -4.3 379 1.9
10000 10.8 51.4 300 18 9 8.6 4.7 25.1 77.2 -4.5 353 1.8
9750 11.5 52.7 300 18 9 8.6 4.7 25.0 77.0 -4.6 327 1.7
9500 12.1 53.8 295 17 9 8.4 4.6 24.9 76.9 -4.7 301 1.5
9250 12.7 54.9 295 16 8 7.7 4.2 24.8 76.7 -4.8 275 1.4
9000 13.3 55.9 295 16 8 8.6 4.7 24.7 76.4 -5.0 251 1.3
8750 14.0 57.2 290 15 8 9.7 5.3 24.6 76.3 -5.0 222 1.1
8500 14.7 58.5 290 14 7 8.8 4.8 24.6 76.3 -5.1 194 1.0
8250 15.3 59.5 290 14 7 7.7 4.2 24.5 76.1 -5.2 169 0.9
8000 16.4 61.5 290 12 6 8.7 4.8 24.2 75.5 -5.5 119 0.6
7750 17.0 62.6 290 11 6 6.7 3.7 24.1 75.4 -5.7 93 0.5
7500 17.4 63.3 285 10 5 4.4 2.4 23.7 74.7 -6.0 75 0.4
7250 17.8 64.0 285 9 4 4.8 2.7 23.3 74.0 -6.4 57 0.3
7000 18.0 64.4 275 8 4 2.0 1.1 22.9 73.2 -6.9 42 0.2
6750 18.0 64.4 265 7 4 -3.4 -1.9 22.1 71.8 -7.7 36 0.2
6500 17.6 63.7 255 7 3 -6.1 -3.4 21.0 69.7 -8.9 41 0.2
6250 17.2 63.0 240 7 3 -3.5 -1.9 19.8 67.7 -10.0 46 0.2
6000 16.8 62.2 230 7 3 -11.6 -6.3 18.7 65.7 -11.2 51 0.3
5750 15.1 59.2 220 6 3 -31.6 -17.3 16.3 61.4 -13.6 93 0.5
5500 13.2 55.8 210 6 3 -3.6 -2.0 13.7 56.7 -16.3 143 0.7
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
03/20/2026 AT 0900 MDT | 03/20/2026 AT 1200 MDT
|
CAPE... 0.0 LI... +4.3 | CAPE... 0.0 LI... +4.7
CINH... 0.0 K INDEX... -10.2 | CINH... -0.0 K INDEX... -9.6
|
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 -65.9 -86.6 315 35 18 3.0 1.6 | -65.4 -85.7 310 32 16 3.0 1.6
45000 -61.4 -78.5 315 41 21 2.5 1.4 | -61.1 -78.0 315 40 20 2.3 1.3
40000 -57.6 -71.7 310 49 25 5.2 2.8 | -57.6 -71.7 315 51 26 4.4 2.4
38000 -53.8 -64.8 310 54 28 6.3 3.5 | -54.2 -65.6 315 52 27 5.6 3.1
36000 -50.0 -58.0 310 60 31 6.3 3.5 | -50.5 -58.9 310 54 28 5.6 3.1
34000 -45.3 -49.5 310 63 32 7.3 4.0 | -45.9 -50.6 310 53 27 8.3 4.6
32000 -41.0 -41.8 310 64 33 7.3 4.0 | -40.9 -41.6 315 51 26 8.3 4.6
30000 -36.2 -33.2 315 61 31 8.2 4.5 | -35.9 -32.6 315 50 26 8.5 4.6
29000 -33.7 -28.7 315 59 30 8.2 4.5 | -33.4 -28.1 315 49 25 8.5 4.6
28000 -31.2 -24.2 315 57 29 8.1 4.4 | -30.8 -23.4 315 49 25 8.3 4.5
27000 -29.0 -20.2 315 54 28 7.3 4.0 | -28.6 -19.5 315 47 24 7.4 4.1
26000 -26.9 -16.4 315 51 26 7.3 4.0 | -26.4 -15.5 320 46 24 7.4 4.1
25000 -24.7 -12.5 320 48 25 7.3 4.0 | -24.1 -11.4 320 44 23 7.5 4.1
24000 -22.5 -8.5 320 45 23 7.5 4.1 | -22.0 -7.6 320 43 22 7.0 3.8
23000 -20.2 -4.4 320 42 22 7.5 4.1 | -19.9 -3.8 320 40 21 7.0 3.8
22000 -18.0 -0.4 320 40 20 7.5 4.1 | -17.3 0.9 320 37 19 7.6 4.2
21000 -14.9 5.2 320 37 19 8.3 4.5 | -14.8 5.4 315 36 19 8.3 4.5
20000 -12.4 9.7 315 35 18 8.3 4.5 | -12.3 9.9 315 35 18 8.3 4.5
19500 -11.2 11.8 315 34 18 8.3 4.5 | -11.1 12.0 315 35 18 8.3 4.5
19000 -10.0 14.0 315 33 17 8.4 4.6 | -9.9 14.2 315 34 17 7.8 4.3
18500 -8.7 16.3 315 32 17 8.4 4.6 | -8.7 16.3 315 33 17 7.9 4.3
18000 -7.5 18.5 315 31 16 8.1 4.5 | -7.5 18.5 315 31 16 7.8 4.3
17500 -6.3 20.7 315 30 15 8.0 4.4 | -6.4 20.5 315 29 15 7.8 4.3
17000 -5.1 22.8 315 29 15 8.0 4.4 | -5.2 22.6 315 27 14 7.8 4.3
16500 -3.9 25.0 320 27 14 8.0 4.4 | -4.0 24.8 315 25 13 7.6 4.2
16000 -2.7 27.1 320 25 13 8.0 4.4 | -2.9 26.8 315 23 12 7.7 4.2
15500 -1.5 29.3 320 24 12 8.0 4.4 | -1.8 28.8 315 21 11 7.6 4.2
15000 -0.3 31.5 320 22 12 8.0 4.4 | -0.6 30.9 315 18 9 7.6 4.2
14500 0.9 33.6 320 21 11 7.9 4.3 | 0.5 32.9 315 16 8 7.7 4.2
14000 2.1 35.8 320 20 10 7.8 4.3 | 1.7 35.1 315 15 7 7.7 4.2
13500 3.3 37.9 325 18 9 7.5 4.1 | 2.8 37.0 315 13 7 7.5 4.1
13000 4.3 39.7 320 17 9 6.9 3.8 | 3.9 39.0 310 12 6 7.1 3.9
12500 5.3 41.5 320 16 8 7.0 3.8 | 4.9 40.8 305 11 6 7.2 4.0
12000 6.3 43.3 320 15 8 7.1 3.9 | 6.0 42.8 300 11 6 7.8 4.3
11500 7.4 45.3 315 15 8 7.2 4.0 | 7.1 44.8 295 11 6 7.9 4.3
11000 8.5 47.3 310 15 8 7.6 4.2 | 8.3 46.9 290 11 5 8.6 4.7
10500 9.6 49.3 300 14 7 7.2 4.0 | 9.6 49.3 285 10 5 8.4 4.6
10250 10.1 50.2 300 14 7 7.5 4.1 | 10.2 50.4 285 10 5 8.4 4.6
10000 10.7 51.3 300 13 7 8.6 4.7 | 10.9 51.6 285 10 5 8.8 4.8
9750 11.3 52.3 295 13 7 8.8 4.8 | 11.5 52.7 285 9 5 8.9 4.9
9500 12.0 53.6 295 12 6 8.3 4.6 | 12.2 54.0 285 8 4 8.5 4.7
9250 12.5 54.5 295 12 6 7.1 3.9 | 12.8 55.0 280 8 4 7.8 4.3
9000 13.1 55.6 290 11 6 8.2 4.5 | 13.3 55.9 280 7 4 8.2 4.5
8750 13.8 56.8 290 11 6 9.8 5.4 | 14.0 57.2 280 6 3 9.1 5.0
8500 14.4 57.9 290 10 5 8.4 4.6 | 14.6 58.3 275 5 3 8.1 4.4
8250 15.0 59.0 290 9 5 6.8 3.7 | 15.2 59.4 270 4 2 6.7 3.7
8000 16.0 60.8 285 8 4 8.0 4.4 | 16.3 61.3 255 3 1 8.7 4.8
7750 16.6 61.9 280 7 4 5.8 3.2 | 16.9 62.4 230 2 1 7.5 4.1
7500 16.9 62.4 275 6 3 3.4 1.9 | 17.4 63.3 215 2 1 6.0 3.3
7250 17.2 63.0 265 6 3 4.2 2.3 | 17.8 64.0 200 2 1 6.8 3.7
7000 17.4 63.3 255 5 3 2.0 1.1 | 18.4 65.1 185 2 1 8.8 4.8
6750 17.4 63.3 245 6 3 -2.7 -1.5 | 19.1 66.4 180 2 1 8.8 4.8
6500 17.1 62.8 235 6 3 -4.2 -2.3 | 19.7 67.5 180 2 1 8.2 4.5
6250 16.8 62.2 230 6 3 -4.6 -2.5 | 20.3 68.5 180 2 1 7.4 4.0
6000 16.4 61.5 220 7 3 -3.8 -2.1 | 20.9 69.6 175 2 1 11.5 6.3
5750 16.2 61.2 215 6 3 1.4 0.8 | 22.1 71.8 175 2 1 22.0 12.1
5500 16.3 61.3 210 5 2 -3.1 -1.7 | 23.5 74.3 175 1 1 5.1 2.8
03/20/2026 AT 1500 MDT | 03/20/2026 AT 1800 MDT
|
CAPE... 0.0 LI... +4.2 | CAPE... 0.0 LI... +3.9
CINH... 0.0 K INDEX... -0.9 | CINH... 0.0 K INDEX... +3.4
|
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 -66.0 -86.8 305 33 17 3.2 1.7 | -65.0 -85.0 310 28 15 2.4 1.3
45000 -61.4 -78.5 310 39 20 2.6 1.4 | -61.4 -78.5 305 37 19 2.3 1.2
40000 -57.5 -71.5 305 58 30 4.5 2.4 | -58.0 -72.4 305 62 32 4.3 2.4
38000 -54.2 -65.6 305 55 28 5.4 3.0 | -54.6 -66.3 310 58 30 5.6 3.1
36000 -50.6 -59.1 310 52 27 5.5 3.0 | -50.8 -59.4 310 54 28 5.7 3.1
34000 -45.9 -50.6 310 49 25 8.5 4.7 | -46.0 -50.8 310 53 27 8.9 4.9
32000 -40.8 -41.4 310 45 23 8.5 4.7 | -40.7 -41.3 315 53 27 8.8 4.9
30000 -35.9 -32.6 310 44 23 8.1 4.5 | -35.8 -32.4 315 47 24 7.9 4.3
29000 -33.5 -28.3 310 43 22 8.1 4.5 | -33.4 -28.1 310 44 23 7.9 4.3
28000 -31.0 -23.8 310 43 22 8.1 4.4 | -31.1 -24.0 310 40 21 7.9 4.3
27000 -28.7 -19.7 310 42 21 7.9 4.3 | -28.8 -19.8 310 38 20 7.7 4.2
26000 -26.3 -15.3 310 40 21 7.9 4.3 | -26.5 -15.7 310 36 19 7.7 4.2
25000 -24.0 -11.2 315 39 20 7.9 4.3 | -24.2 -11.6 310 34 18 7.6 4.2
24000 -21.7 -7.1 315 38 20 7.8 4.3 | -21.8 -7.2 305 33 17 8.2 4.5
23000 -19.3 -2.7 315 37 19 7.8 4.3 | -19.3 -2.7 305 33 17 8.2 4.5
22000 -16.4 2.5 315 35 18 7.9 4.4 | -16.3 2.7 300 32 16 8.2 4.5
21000 -14.0 6.8 310 35 18 8.0 4.4 | -13.9 7.0 300 31 16 8.1 4.4
20000 -11.6 11.1 310 35 18 8.0 4.4 | -11.5 11.3 295 30 15 8.1 4.4
19500 -10.4 13.3 310 35 18 8.0 4.4 | -10.3 13.5 295 29 15 8.0 4.4
19000 -9.2 15.4 310 34 17 7.3 4.0 | -9.1 15.6 295 28 14 7.1 3.9
18500 -8.1 17.4 310 33 17 7.3 4.0 | -8.1 17.4 290 27 14 7.2 3.9
18000 -7.0 19.4 305 31 16 7.1 3.9 | -7.0 19.4 285 25 13 7.2 4.0
17500 -6.0 21.2 305 29 15 7.0 3.8 | -6.0 21.2 280 24 12 7.3 4.0
17000 -5.0 23.0 300 27 14 7.0 3.8 | -4.9 23.2 275 23 12 7.4 4.1
16500 -3.9 25.0 295 26 13 7.3 4.0 | -3.7 25.3 270 21 11 8.5 4.7
16000 -2.9 26.8 290 24 12 7.2 4.0 | -2.5 27.5 265 20 10 8.5 4.6
15500 -1.8 28.8 285 22 12 8.0 4.4 | -1.2 29.8 265 19 10 8.0 4.4
15000 -0.6 30.9 285 21 11 8.0 4.4 | -0.1 31.8 265 18 9 8.0 4.4
14500 0.6 33.1 280 20 11 8.4 4.6 | 1.1 34.0 270 17 9 8.3 4.6
14000 1.9 35.4 280 20 10 8.6 4.7 | 2.4 36.3 270 16 8 8.5 4.7
13500 3.2 37.8 280 19 10 8.7 4.8 | 3.7 38.7 275 16 8 8.5 4.7
13000 4.5 40.1 280 18 9 8.8 4.9 | 4.9 40.8 280 14 7 8.4 4.6
12500 5.8 42.4 280 17 9 8.8 4.8 | 6.2 43.2 285 13 7 8.4 4.6
12000 7.1 44.8 285 15 8 8.7 4.8 | 7.4 45.3 290 12 6 8.6 4.7
11500 8.4 47.1 285 14 7 8.6 4.7 | 8.7 47.7 290 10 5 8.6 4.7
11000 9.6 49.3 290 12 6 8.2 4.5 | 10.0 50.0 295 9 4 9.2 5.0
10500 10.9 51.6 295 9 5 7.3 4.0 | 11.4 52.5 295 7 4 8.4 4.6
10250 11.4 52.5 295 8 4 7.7 4.2 | 12.0 53.6 295 7 3 8.5 4.7
10000 12.0 53.6 295 7 4 9.2 5.1 | 12.7 54.9 300 6 3 9.5 5.2
9750 12.7 54.9 295 6 3 8.9 4.9 | 13.4 56.1 300 5 3 9.2 5.1
9500 13.4 56.1 295 5 3 8.7 4.8 | 14.1 57.4 300 5 2 9.2 5.0
9250 14.0 57.2 300 4 2 8.1 4.5 | 14.8 58.6 305 4 2 8.9 4.9
9000 14.6 58.3 300 3 2 9.0 5.0 | 15.4 59.7 305 4 2 9.4 5.2
8750 15.3 59.5 305 3 1 9.9 5.4 | 16.2 61.2 310 3 2 10.0 5.5
8500 16.0 60.8 310 2 1 9.5 5.2 | 16.9 62.4 315 3 1 9.6 5.3
8250 16.7 62.1 315 2 1 8.8 4.8 | 17.6 63.7 325 2 1 8.5 4.7
8000 18.1 64.6 345 1 0 10.5 5.8 | 19.0 66.2 345 2 1 11.1 6.1
7750 18.9 66.0 010 1 0 9.9 5.4 | 19.8 67.6 360 2 1 10.1 5.5
7500 19.6 67.3 035 1 0 9.2 5.0 | 20.5 68.9 015 2 1 8.8 4.8
7250 20.3 68.5 055 1 1 9.4 5.2 | 21.2 70.2 025 2 1 9.0 4.9
7000 21.0 69.8 065 1 1 10.4 5.7 | 21.9 71.4 035 2 1 10.0 5.5
6750 21.8 71.2 070 1 1 10.3 5.7 | 22.6 72.7 040 2 1 10.2 5.6
6500 22.6 72.7 070 2 1 10.0 5.5 | 23.4 74.1 045 2 1 9.8 5.4
6250 23.3 73.9 075 2 1 9.5 5.2 | 24.1 75.4 045 2 1 10.0 5.5
6000 24.1 75.4 075 2 1 12.2 6.7 | 24.8 76.6 050 3 1 9.6 5.3
5750 25.3 77.5 075 2 1 19.7 10.8 | 25.5 77.9 050 3 1 8.7 4.8
5500 26.6 79.9 075 2 1 13.3 7.3 | 26.0 78.8 050 3 1 9.3 5.1
________________________________________________________________________________
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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