903
UXUS97 KBOU 191243
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
0641 MDT THURSDAY, MARCH 19, 2026
THIS FORECAST IS FOR THURSDAY, MARCH 19, 2026:
IF THE TRIGGER TEMPERATURE OF 73.8 F/23.2 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1013 FT/MIN (5.1 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 16756 FT MSL (11458 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 84.0 F/29.3 C
TIME OF TRIGGER TEMPERATURE.................... 1045 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................. 14055 FT MSL (8757 FT AGL)
THERMAL SOARING OUTLOOK FOR FRIDAY 03/20....... EXCELLENT
WAVE SOARING INDEX............................. FAIR
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....................... 31623 FT MSL (26325 FT AGL)
WAVE SOARING OUTLOOK FOR FRIDAY 03/20.......... POOR
REMARKS... LIGHTER WEST/NORTHWEST FLOW ALOFT TODAY AND FRIDAY. VERY WARM!.
SUNRISE/SUNSET.................... 07:03:52 / 19:10:23 MDT
TOTAL POSSIBLE SUNSHINE........... 12 HR 6 MIN 31 SEC (726 MIN 31 SEC)
ALTITUDE OF SUN AT 13:07:07 MDT... 49.88 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 03/19/2026 AT 0600 MDT
FREEZING LEVEL.................. 13774 FT MSL (8476 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 21206 FT MSL (15908 FT AGL)
LIFTED CONDENSATION LEVEL....... 19611 FT MSL (14313 FT AGL)
LIFTED INDEX.................... +3.2
K INDEX......................... -4.8
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 -68.3 -90.9 315 37 19 2.3 1.3 M M M M M
45000 -64.0 -83.2 315 51 26 4.1 2.3 M M M M M
40000 -57.7 -71.9 310 68 35 6.9 3.8 M M M M M
38000 -53.6 -64.5 310 68 35 6.9 3.8 M M M M M
36000 -49.4 -56.9 315 69 36 6.9 3.8 M M M M M
34000 -44.7 -48.5 315 72 37 8.4 4.6 M M M M M
32000 -39.6 -39.3 320 76 39 8.4 4.6 M M M M M
30000 -34.0 -29.2 320 76 39 8.4 4.6 41.7 107.1 9.8 M M
29000 -31.4 -24.5 320 76 39 8.4 4.6 41.3 106.3 9.5 M M
28000 -28.9 -20.0 320 75 39 7.9 4.4 40.9 105.6 9.3 M M
27000 -26.7 -16.1 320 72 37 7.3 4.0 39.8 103.7 8.6 M M
26000 -24.5 -12.1 320 70 36 7.3 4.0 38.9 102.0 8.0 M M
25000 -22.3 -8.1 320 67 34 7.4 4.1 38.1 100.6 7.4 M M
24000 -20.3 -4.5 320 63 32 6.8 3.7 37.0 98.6 6.6 M M
23000 -18.3 -0.9 320 58 30 6.8 3.7 35.9 96.6 5.7 M M
22000 -16.2 2.8 320 54 28 6.8 3.7 34.9 94.8 5.0 M M
21000 -14.1 6.6 320 50 26 7.2 3.9 33.9 93.0 4.1 M M
20000 -12.0 10.4 320 46 24 7.2 3.9 33.0 91.3 3.4 M M
19500 -10.9 12.4 320 44 23 7.2 4.0 32.5 90.6 3.1 M M
19000 -9.9 14.2 320 42 21 6.1 3.4 32.1 89.7 2.7 M M
18500 -9.0 15.8 320 39 20 6.0 3.3 31.4 88.5 2.1 M M
18000 -8.1 17.4 320 36 18 6.0 3.3 30.8 87.4 1.6 M M
17500 -7.2 19.0 320 33 17 5.9 3.2 30.1 86.2 1.0 M M
17000 -6.3 20.7 320 31 16 5.9 3.2 29.4 85.0 0.4 M M
16500 -5.5 22.1 320 29 15 5.9 3.2 28.8 83.8 -0.2 1001 5.1
16000 -4.2 24.4 320 27 14 5.8 3.2 27.8 82.0 -1.1 940 4.8
15500 -3.3 26.1 320 25 13 6.2 3.4 27.2 80.9 -1.6 898 4.6
15000 -2.4 27.7 320 24 12 6.1 3.3 26.6 79.8 -2.2 856 4.3
14500 -1.4 29.5 320 22 11 7.4 4.1 26.0 78.9 -2.7 813 4.1
14000 -0.3 31.5 320 21 11 7.7 4.2 25.7 78.2 -3.1 765 3.9
13500 0.8 33.4 320 21 11 8.4 4.6 25.4 77.7 -3.5 716 3.6
13000 2.1 35.8 320 21 11 8.7 4.8 25.2 77.4 -3.7 663 3.4
12500 3.4 38.1 320 22 11 8.7 4.8 25.1 77.1 -3.9 611 3.1
12000 4.6 40.3 320 23 12 8.6 4.7 24.9 76.8 -4.1 558 2.8
11500 5.9 42.6 320 25 13 8.4 4.6 24.7 76.5 -4.3 506 2.6
11000 7.1 44.8 315 24 13 8.0 4.4 24.4 76.0 -4.6 455 2.3
10500 8.3 46.9 315 24 12 5.3 2.9 24.2 75.6 -4.9 404 2.1
10250 8.5 47.3 315 24 12 4.7 2.6 23.7 74.7 -5.4 389 2.0
10000 9.2 48.6 315 23 12 10.7 5.9 23.6 74.5 -5.5 363 1.8
9750 10.0 50.0 315 22 12 12.6 6.9 23.8 74.8 -5.4 329 1.7
9500 10.9 51.6 320 22 11 9.1 5.0 23.9 75.0 -5.2 295 1.5
9250 11.4 52.5 320 22 11 5.3 2.9 23.6 74.6 -5.5 273 1.4
9000 11.9 53.4 320 21 11 8.7 4.8 23.4 74.1 -5.7 251 1.3
8750 12.7 54.9 320 21 11 10.8 5.9 23.4 74.2 -5.7 220 1.1
8500 13.4 56.1 320 20 10 8.6 4.7 23.4 74.2 -5.7 191 1.0
8250 14.0 57.2 320 20 10 7.3 4.0 23.3 73.9 -5.9 166 0.8
8000 14.6 58.3 320 19 10 8.6 4.7 23.1 73.7 -6.1 142 0.7
7750 15.2 59.4 320 19 10 9.2 5.0 23.1 73.6 -6.1 114 0.6
7500 15.9 60.6 320 20 10 7.7 4.2 23.0 73.4 -6.3 88 0.4
7250 16.4 61.5 315 20 10 6.5 3.5 22.8 73.0 -6.5 65 0.3
7000 16.9 62.4 315 20 10 8.4 4.6 22.6 72.6 -6.7 42 0.2
6750 17.4 63.3 315 20 10 3.7 2.0 22.4 72.3 -6.9 18 0.1
6500 17.4 63.3 305 20 10 -2.9 -1.6 21.6 70.9 -7.7 13 0.1
6250 17.3 63.1 300 19 10 2.5 1.4 20.8 69.4 -8.5 7 0.0
6000 17.3 63.1 295 19 10 -12.9 -7.1 20.0 68.0 -9.3 2 0.0
5750 15.1 59.2 280 15 8 -36.9 -20.3 17.2 62.9 -12.2 58 0.3
5500 12.3 54.1 265 9 5 -31.7 -17.4 13.7 56.6 -15.8 135 0.7
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
03/19/2026 AT 0900 MDT | 03/19/2026 AT 1200 MDT
|
CAPE... 0.0 LI... +7.1 | CAPE... 0.0 LI... +6.5
CINH... 0.0 K INDEX... -11.1 | CINH... 0.0 K INDEX... -15.7
|
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 -67.8 -90.0 315 40 21 2.7 1.5 | -67.4 -89.3 315 39 20 2.6 1.4
45000 -63.5 -82.3 315 48 25 3.5 1.9 | -63.3 -81.9 315 49 25 3.1 1.7
40000 -57.9 -72.2 315 72 37 7.2 3.9 | -58.3 -72.9 315 72 37 8.1 4.5
38000 -53.6 -64.5 315 72 37 7.1 3.9 | -53.7 -64.7 310 71 37 7.7 4.3
36000 -49.4 -56.9 315 73 38 7.2 3.9 | -49.0 -56.2 310 70 36 7.8 4.3
34000 -44.6 -48.3 315 72 37 8.3 4.6 | -44.1 -47.4 310 67 35 8.3 4.5
32000 -39.0 -38.2 315 69 36 8.3 4.5 | -38.5 -37.3 310 62 32 8.2 4.5
30000 -33.9 -29.0 315 68 35 8.4 4.6 | -33.8 -28.8 310 61 31 7.8 4.3
29000 -31.4 -24.5 315 67 35 8.4 4.6 | -31.5 -24.7 310 60 31 7.8 4.3
28000 -28.9 -20.0 315 67 34 8.0 4.4 | -29.1 -20.4 310 60 31 7.8 4.3
27000 -26.6 -15.9 315 65 33 7.6 4.2 | -26.8 -16.2 310 58 30 7.8 4.3
26000 -24.3 -11.7 315 63 32 7.6 4.2 | -24.4 -11.9 310 56 29 7.8 4.3
25000 -22.0 -7.6 320 61 31 7.7 4.2 | -22.1 -7.8 310 55 28 7.9 4.3
24000 -20.0 -4.0 320 57 29 6.5 3.6 | -20.0 -4.0 310 51 26 6.7 3.7
23000 -18.0 -0.4 320 53 27 6.6 3.6 | -18.0 -0.4 310 48 24 6.7 3.7
22000 -16.1 3.0 320 49 25 6.7 3.7 | -15.9 3.4 310 44 22 6.9 3.8
21000 -13.9 7.0 320 46 24 7.3 4.0 | -13.7 7.3 310 41 21 7.5 4.1
20000 -11.8 10.8 320 42 22 7.3 4.0 | -11.5 11.3 310 38 19 7.5 4.1
19500 -10.7 12.7 315 41 21 7.4 4.0 | -10.4 13.3 310 36 19 7.6 4.2
19000 -9.6 14.7 315 39 20 6.6 3.6 | -9.3 15.3 310 35 18 6.7 3.7
18500 -8.6 16.5 315 36 19 6.6 3.6 | -8.3 17.1 310 33 17 6.7 3.7
18000 -7.7 18.1 315 33 17 6.7 3.7 | -7.3 18.9 310 32 16 7.0 3.8
17500 -6.6 20.1 315 31 16 7.2 4.0 | -6.2 20.8 310 30 16 7.7 4.2
17000 -5.5 22.1 315 28 14 7.3 4.0 | -5.0 23.0 310 29 15 7.9 4.3
16500 -4.0 24.8 315 26 13 6.7 3.7 | -3.5 25.7 310 26 13 5.9 3.2
16000 -3.0 26.6 320 25 13 6.7 3.7 | -2.7 27.1 310 23 12 5.9 3.2
15500 -2.0 28.4 320 23 12 6.2 3.4 | -1.7 28.9 310 22 11 6.7 3.7
15000 -1.1 30.0 320 22 11 6.3 3.4 | -0.7 30.7 310 20 10 6.7 3.7
14500 -0.1 31.8 320 21 11 6.3 3.5 | 0.2 32.4 315 19 10 5.9 3.2
14000 0.8 33.4 320 20 10 6.4 3.5 | 1.1 34.0 315 18 9 5.8 3.2
13500 1.7 35.1 320 19 10 6.5 3.6 | 2.0 35.6 315 16 8 6.3 3.4
13000 2.7 36.9 320 18 10 6.5 3.6 | 2.9 37.2 315 15 8 6.4 3.5
12500 3.6 38.5 320 18 9 6.7 3.7 | 3.9 39.0 315 13 7 6.3 3.4
12000 4.6 40.3 320 17 9 6.8 3.7 | 4.8 40.6 315 12 6 6.2 3.4
11500 5.6 42.1 320 16 8 7.1 3.9 | 5.7 42.3 315 10 5 6.8 3.8
11000 6.7 44.1 320 15 8 7.3 4.0 | 6.8 44.2 315 9 5 7.3 4.0
10500 7.7 45.9 315 14 7 5.4 3.0 | 7.8 46.0 320 8 4 4.4 2.4
10250 8.0 46.4 320 14 7 4.8 2.6 | 8.0 46.4 315 8 4 4.2 2.3
10000 8.6 47.5 320 14 7 9.4 5.2 | 8.6 47.5 315 8 4 10.6 5.8
9750 9.4 48.9 320 14 7 10.9 6.0 | 9.5 49.1 315 8 4 12.0 6.6
9500 10.1 50.2 325 14 7 8.7 4.8 | 10.3 50.5 315 8 4 8.5 4.7
9250 10.7 51.3 320 14 7 7.2 3.9 | 10.7 51.3 315 9 4 5.6 3.1
9000 11.2 52.2 320 15 7 8.1 4.4 | 11.2 52.2 310 9 5 8.6 4.7
8750 11.9 53.4 320 14 7 8.6 4.7 | 12.0 53.6 310 10 5 10.1 5.5
8500 12.5 54.5 320 14 7 8.6 4.7 | 12.6 54.7 310 11 6 7.7 4.3
8250 13.1 55.6 320 14 7 8.5 4.7 | 13.1 55.6 305 10 5 6.7 3.7
8000 13.8 56.8 320 14 7 8.9 4.9 | 13.6 56.5 305 10 5 8.2 4.5
7750 14.4 57.9 320 15 8 8.5 4.7 | 14.3 57.7 305 9 5 9.3 5.1
7500 15.0 59.0 315 15 8 7.4 4.1 | 14.9 58.8 305 8 4 8.5 4.6
7250 15.6 60.1 315 16 8 7.2 3.9 | 15.5 59.9 300 7 4 8.2 4.5
7000 16.1 61.0 310 17 9 7.6 4.2 | 16.1 61.0 295 7 3 8.6 4.7
6750 16.6 61.9 305 18 9 3.6 2.0 | 16.8 62.2 290 6 3 9.6 5.3
6500 16.6 61.9 300 17 9 -0.9 -0.5 | 17.5 63.5 285 5 3 10.0 5.5
6250 16.6 61.9 295 16 8 3.6 1.9 | 18.3 64.9 280 5 3 9.9 5.4
6000 16.7 62.1 285 16 8 -9.7 -5.3 | 19.0 66.2 275 5 2 10.0 5.5
5750 15.1 59.2 275 12 6 -24.3 -13.3 | 19.8 67.6 275 5 2 14.6 8.0
5500 13.6 56.5 260 8 4 -10.0 -5.5 | 21.2 70.2 275 4 2 22.0 12.0
03/19/2026 AT 1500 MDT | 03/19/2026 AT 1800 MDT
|
CAPE... 0.0 LI... +4.5 | CAPE... 0.0 LI... +2.8
CINH... 0.0 K INDEX... -6.9 | CINH... 0.0 K INDEX... -2.1
|
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 -67.2 -89.0 305 43 22 2.3 1.3 | -66.5 -87.7 310 46 23 2.9 1.6
45000 -63.4 -82.1 305 52 27 3.1 1.7 | -62.1 -79.8 310 54 28 2.6 1.4
40000 -58.4 -73.1 305 74 38 7.9 4.3 | -58.0 -72.4 305 75 39 6.8 3.7
38000 -53.8 -64.8 305 75 39 7.7 4.2 | -53.7 -64.7 305 80 41 7.2 4.0
36000 -49.2 -56.6 305 76 39 7.7 4.2 | -49.3 -56.7 305 84 43 7.2 4.0
34000 -44.5 -48.1 305 72 37 7.8 4.3 | -45.1 -49.2 305 80 41 6.9 3.8
32000 -39.2 -38.6 305 65 34 7.7 4.3 | -40.5 -40.9 305 71 36 6.8 3.7
30000 -34.5 -30.1 305 62 32 7.9 4.3 | -35.7 -32.3 305 66 34 8.3 4.6
29000 -32.1 -25.8 305 60 31 7.9 4.3 | -33.2 -27.8 305 64 33 8.3 4.6
28000 -29.8 -21.6 305 58 30 8.2 4.5 | -30.7 -23.3 305 63 32 8.2 4.5
27000 -27.2 -17.0 305 58 30 8.5 4.7 | -28.3 -18.9 310 59 30 8.0 4.4
26000 -24.7 -12.5 310 57 29 8.5 4.7 | -25.9 -14.6 310 55 28 8.0 4.4
25000 -22.1 -7.8 310 57 29 8.6 4.7 | -23.6 -10.5 310 51 26 8.0 4.4
24000 -20.1 -4.2 310 53 27 6.3 3.5 | -21.4 -6.5 315 48 25 7.1 3.9
23000 -18.2 -0.8 310 49 25 6.3 3.5 | -19.2 -2.6 315 45 23 7.1 3.9
22000 -16.3 2.7 310 44 23 6.5 3.6 | -17.1 1.2 315 43 22 7.2 3.9
21000 -14.2 6.4 310 41 21 7.4 4.0 | -14.9 5.2 315 38 20 7.3 4.0
20000 -12.0 10.4 310 37 19 7.4 4.1 | -12.8 9.0 315 33 17 7.3 4.0
19500 -10.9 12.4 310 35 18 7.4 4.1 | -11.7 10.9 315 31 16 7.3 4.0
19000 -9.8 14.4 310 33 17 7.1 3.9 | -10.6 12.9 310 28 14 7.3 4.0
18500 -8.7 16.3 305 30 16 7.1 3.9 | -9.5 14.9 310 25 13 7.3 4.0
18000 -7.6 18.3 305 27 14 7.2 3.9 | -8.4 16.9 305 22 11 7.6 4.2
17500 -6.6 20.1 305 25 13 7.3 4.0 | -7.2 19.0 310 21 11 8.3 4.5
17000 -5.5 22.1 300 23 12 7.3 4.0 | -5.9 21.4 310 20 10 8.3 4.5
16500 -3.9 25.0 300 21 11 7.1 3.9 | -4.7 23.5 310 19 10 8.6 4.7
16000 -2.8 27.0 300 20 10 7.1 3.9 | -2.8 27.0 315 20 10 8.6 4.7
15500 -1.8 28.8 300 19 10 6.3 3.5 | -1.5 29.3 315 20 10 8.5 4.7
15000 -0.9 30.4 300 19 10 6.3 3.5 | -0.2 31.6 315 20 10 8.7 4.8
14500 0.1 32.2 300 18 9 7.1 3.9 | 1.0 33.8 315 20 10 7.1 3.9
14000 1.2 34.2 300 16 8 7.1 3.9 | 2.0 35.6 315 20 10 7.0 3.9
13500 2.2 36.0 300 14 7 7.3 4.0 | 3.1 37.6 310 19 10 7.5 4.1
13000 3.3 37.9 300 14 7 7.4 4.1 | 4.2 39.6 310 19 10 7.7 4.2
12500 4.4 39.9 300 14 7 8.2 4.5 | 5.3 41.5 310 18 10 7.4 4.1
12000 5.7 42.3 300 15 8 8.7 4.8 | 6.4 43.5 305 20 10 7.2 4.0
11500 7.0 44.6 300 16 8 8.2 4.5 | 7.4 45.3 305 21 11 7.5 4.1
11000 8.1 46.6 295 17 9 7.5 4.1 | 8.5 47.3 300 22 11 7.6 4.2
10500 9.2 48.6 290 18 9 4.2 2.3 | 9.7 49.5 295 22 11 3.5 1.9
10250 9.4 48.9 290 17 9 4.0 2.2 | 9.7 49.5 295 22 11 3.7 2.0
10000 9.9 49.8 290 15 8 9.7 5.3 | 10.3 50.5 295 20 10 11.0 6.0
9750 10.6 51.1 285 12 6 10.0 5.5 | 11.1 52.0 295 18 9 11.0 6.0
9500 11.3 52.3 285 10 5 8.3 4.5 | 11.9 53.4 290 17 9 8.8 4.8
9250 11.8 53.2 285 10 5 6.4 3.5 | 12.4 54.3 290 16 8 6.6 3.6
9000 12.4 54.3 280 9 5 10.0 5.5 | 13.0 55.4 290 16 8 10.0 5.5
8750 13.2 55.8 280 9 5 12.1 6.7 | 13.8 56.8 290 15 8 11.9 6.5
8500 14.0 57.2 280 9 5 10.0 5.5 | 14.6 58.3 290 15 8 9.8 5.4
8250 14.7 58.5 280 9 4 9.3 5.1 | 15.3 59.5 290 14 7 8.9 4.9
8000 15.5 59.9 280 9 4 9.9 5.4 | 16.0 60.8 295 14 7 9.5 5.2
7750 16.2 61.2 275 9 4 10.2 5.6 | 16.7 62.1 295 13 7 10.1 5.5
7500 17.0 62.6 275 8 4 9.9 5.4 | 17.5 63.5 295 13 7 10.2 5.6
7250 17.7 63.9 275 8 4 9.7 5.3 | 18.3 64.9 295 13 7 10.3 5.6
7000 18.4 65.1 275 8 4 10.4 5.7 | 19.0 66.2 295 13 6 9.8 5.4
6750 19.2 66.6 275 8 4 10.4 5.7 | 19.7 67.5 295 12 6 9.6 5.3
6500 20.0 68.0 275 8 4 9.8 5.4 | 20.5 68.9 295 12 6 9.9 5.4
6250 20.7 69.3 275 8 4 9.7 5.3 | 21.2 70.2 295 12 6 9.9 5.4
6000 21.5 70.7 275 8 4 10.7 5.9 | 21.9 71.4 295 11 6 9.6 5.3
5750 22.4 72.3 275 8 4 15.7 8.6 | 22.6 72.7 295 10 5 8.8 4.8
5500 23.8 74.8 275 7 4 20.7 11.3 | 23.2 73.8 295 9 5 8.4 4.6
________________________________________________________________________________
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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