863
UXUS97 KBOU 301328
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
0727 MDT TUESDAY, JUNE 30, 2026
THIS FORECAST IS FOR TUESDAY, JUNE 30, 2026:
IF THE TRIGGER TEMPERATURE OF 75.3 F/24.0 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1371 FT/MIN (7.0 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 20648 FT MSL (15286 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 92.0 F/33.8 C
TIME OF TRIGGER TEMPERATURE.................... 0930 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................. 16956 FT MSL (11594 FT AGL)
THERMAL SOARING OUTLOOK FOR WEDNESDAY 07/01.... EXCELLENT
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1800 MDT)......... LITTLE TO NO CHANGE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... 7000 FT MSL (1638 FT AGL)
WEAK PVA/NVA (THROUGH 1800 MDT)................ WEAK PVA
POTENTIAL HEIGHT OF WAVE....................... 46119 FT MSL (40757 FT AGL)
WAVE SOARING OUTLOOK FOR WEDNESDAY 07/01....... POOR
REMARKS...
SUNRISE/SUNSET.................... 05:34:53 / 20:31:37 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 56 MIN 44 SEC (896 MIN 44 SEC)
ALTITUDE OF SUN AT 13:03:15 MDT... 73.35 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 06/30/2026 AT 0600 MDT
FREEZING LEVEL.................. 14851 FT MSL (9489 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 17969 FT MSL (12607 FT AGL)
LIFTED CONDENSATION LEVEL....... 19176 FT MSL (13814 FT AGL)
LIFTED INDEX.................... -1.7
K INDEX......................... +8.4
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 -61.1 -78.0 225 49 25 2.3 1.2 M M M M M
45000 -57.3 -71.1 225 67 34 2.8 1.6 M M M M M
40000 -52.8 -63.0 220 66 34 5.8 3.2 M M M M M
38000 -49.5 -57.1 220 65 33 5.5 3.0 M M M M M
36000 -46.2 -51.2 220 63 33 5.6 3.1 M M M M M
34000 -41.8 -43.2 220 63 32 8.0 4.4 M M M M M
32000 -36.4 -33.5 225 63 32 8.0 4.4 M M M M M
30000 -32.1 -25.8 225 59 30 6.8 3.7 43.6 110.5 7.8 M M
29000 -30.1 -22.2 230 56 29 6.8 3.7 42.5 108.5 7.1 M M
28000 -28.0 -18.4 230 54 28 6.9 3.8 41.5 106.7 6.4 M M
27000 -25.9 -14.6 230 51 26 7.1 3.9 40.4 104.7 5.6 M M
26000 -23.8 -10.8 230 49 25 7.1 3.9 39.4 102.9 4.8 M M
25000 -21.7 -7.1 230 47 24 7.1 3.9 38.5 101.2 4.1 M M
24000 -19.7 -3.5 230 45 23 6.5 3.6 37.3 99.2 3.2 M M
23000 -17.7 0.1 230 43 22 6.5 3.6 36.1 97.0 2.3 M M
22000 -15.8 3.6 230 41 21 6.5 3.5 35.0 95.0 1.4 M M
21000 -13.8 7.2 230 39 20 6.8 3.7 33.9 93.0 0.4 M M
20000 -11.8 10.8 230 38 19 6.8 3.7 32.8 91.1 -0.5 1320 6.7
19500 -10.8 12.6 230 37 19 6.8 3.8 32.3 90.2 -0.9 1275 6.5
19000 -9.8 14.4 225 36 19 7.1 3.9 31.9 89.4 -1.3 1230 6.2
18500 -8.7 16.3 230 36 18 7.4 4.0 31.4 88.6 -1.7 1182 6.0
18000 -7.1 19.2 230 35 18 7.5 4.1 30.9 87.5 -2.3 1111 5.6
17500 -5.9 21.4 230 35 18 7.5 4.1 30.5 86.8 -2.7 1063 5.4
17000 -4.8 23.4 230 34 18 7.5 4.1 30.1 86.2 -3.0 1015 5.2
16500 -3.7 25.3 235 33 17 7.8 4.3 29.7 85.5 -3.4 967 4.9
16000 -2.6 27.3 235 32 17 7.8 4.3 29.4 84.9 -3.7 918 4.7
15500 -1.4 29.5 235 31 16 8.1 4.5 29.1 84.4 -4.1 869 4.4
15000 -0.2 31.6 235 29 15 8.3 4.5 28.8 83.9 -4.3 818 4.2
14500 1.0 33.8 240 27 14 8.5 4.7 28.6 83.5 -4.6 766 3.9
14000 2.3 36.1 235 25 13 8.9 4.9 28.4 83.2 -4.8 712 3.6
13500 3.6 38.5 235 23 12 8.9 4.9 28.3 82.9 -4.9 658 3.3
13000 4.9 40.8 235 22 11 8.6 4.7 28.1 82.6 -5.1 605 3.1
12500 6.2 43.2 230 20 10 8.6 4.7 27.9 82.3 -5.3 552 2.8
12000 7.4 45.3 225 18 9 7.6 4.2 27.7 81.8 -5.7 502 2.5
11500 8.5 47.3 220 16 8 8.1 4.4 27.3 81.2 -6.0 454 2.3
11000 9.4 48.9 210 14 7 4.9 2.7 26.8 80.3 -6.6 411 2.1
10500 10.1 50.2 200 12 6 4.6 2.5 26.1 79.0 -7.4 375 1.9
10250 10.5 50.9 190 12 6 8.1 4.4 25.8 78.4 -7.8 357 1.8
10000 11.1 52.0 180 11 6 8.2 4.5 25.8 78.4 -7.9 330 1.7
9750 11.5 52.7 175 11 6 4.9 2.7 25.5 77.8 -8.3 312 1.6
9500 11.8 53.2 170 11 6 5.9 3.2 25.1 77.2 -8.7 294 1.5
9250 12.2 54.0 165 11 6 5.6 3.0 24.8 76.7 -9.0 276 1.4
9000 12.6 54.7 155 12 6 6.6 3.6 24.5 76.1 -9.4 255 1.3
8750 13.2 55.8 145 13 6 7.5 4.1 24.3 75.8 -9.6 231 1.2
8500 13.7 56.7 140 13 7 7.3 4.0 24.1 75.5 -9.8 207 1.1
8250 14.3 57.7 135 14 7 5.8 3.2 23.9 75.1 -10.0 184 0.9
8000 14.7 58.5 130 15 8 5.0 2.8 23.6 74.4 -10.3 163 0.8
7750 15.2 59.4 125 15 8 6.1 3.3 23.2 73.8 -10.5 141 0.7
7500 15.7 60.3 125 14 7 5.9 3.2 23.0 73.3 -10.8 119 0.6
7250 16.2 61.2 125 13 7 5.2 2.9 22.6 72.8 -11.1 98 0.5
7000 16.5 61.7 125 13 7 4.9 2.7 22.3 72.1 -11.5 80 0.4
6750 16.9 62.4 130 12 6 5.7 3.1 21.9 71.5 -11.9 62 0.3
6500 17.2 63.0 140 11 6 4.9 2.7 21.6 70.9 -12.3 44 0.2
6250 17.4 63.3 145 10 5 3.2 1.7 21.2 70.1 -12.8 30 0.2
6000 17.7 63.9 155 9 5 4.4 2.4 20.7 69.3 -13.4 16 0.1
5750 17.9 64.2 165 8 4 1.1 0.6 20.3 68.5 -13.9 2 0.0
5500 17.4 63.3 175 6 3 -14.6 -8.0 19.1 66.4 -15.1 8 0.0
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
06/30/2026 AT 0900 MDT | 06/30/2026 AT 1200 MDT
|
CAPE... 0.0 LI... +2.4 | CAPE... +6.4 LI... +1.1
CINH... -0.1 K INDEX... +11.7 | CINH... -3.1 K INDEX... +16.6
|
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 -60.3 -76.5 220 51 26 2.8 1.6 | -60.7 -77.3 220 55 28 3.3 1.8
45000 -56.4 -69.5 225 64 33 1.6 0.9 | -56.2 -69.2 220 65 33 1.6 0.9
40000 -53.6 -64.5 220 70 36 6.2 3.4 | -53.5 -64.3 220 70 36 6.0 3.3
38000 -50.2 -58.4 220 66 34 5.6 3.1 | -50.1 -58.2 220 67 34 5.7 3.1
36000 -46.9 -52.4 215 63 32 5.7 3.1 | -46.7 -52.1 215 64 33 5.7 3.1
34000 -42.6 -44.7 215 61 31 7.8 4.3 | -42.8 -45.0 210 61 32 7.0 3.8
32000 -37.3 -35.1 210 59 31 7.8 4.3 | -38.1 -36.6 210 59 31 7.1 3.9
30000 -32.8 -27.0 215 56 29 7.4 4.0 | -33.5 -28.3 210 57 29 7.9 4.3
29000 -30.6 -23.1 215 55 28 7.4 4.0 | -31.1 -24.0 215 56 29 7.9 4.3
28000 -28.4 -19.1 220 53 27 7.3 4.0 | -28.8 -19.8 215 55 28 7.9 4.3
27000 -26.2 -15.2 220 51 26 7.2 4.0 | -26.5 -15.7 215 53 27 7.7 4.2
26000 -24.1 -11.4 220 48 25 7.2 4.0 | -24.2 -11.6 215 50 26 7.7 4.2
25000 -21.9 -7.4 220 45 23 7.2 4.0 | -21.9 -7.4 215 48 25 7.7 4.2
24000 -19.9 -3.8 220 43 22 6.8 3.7 | -19.7 -3.5 215 46 24 7.2 3.9
23000 -17.9 -0.2 220 42 21 6.8 3.7 | -17.5 0.5 215 44 23 7.2 3.9
22000 -15.8 3.6 220 40 21 6.8 3.7 | -15.4 4.3 215 43 22 7.2 4.0
21000 -13.8 7.2 220 40 21 7.1 3.9 | -13.4 7.9 220 42 22 6.6 3.6
20000 -11.7 10.9 220 41 21 7.2 3.9 | -11.4 11.5 220 41 21 6.6 3.6
19500 -10.7 12.7 220 41 21 7.2 3.9 | -10.5 13.1 225 41 21 6.7 3.7
19000 -9.6 14.7 220 42 22 7.0 3.8 | -9.5 14.9 225 40 21 6.8 3.8
18500 -8.2 17.2 225 43 22 6.9 3.8 | -8.0 17.6 225 40 21 7.1 3.9
18000 -7.2 19.0 225 43 22 7.2 3.9 | -7.0 19.4 225 39 20 7.3 4.0
17500 -6.1 21.0 225 43 22 7.5 4.1 | -5.9 21.4 225 39 20 7.6 4.2
17000 -5.0 23.0 225 42 22 7.5 4.1 | -4.8 23.4 225 38 20 7.6 4.2
16500 -3.9 25.0 225 40 21 7.8 4.3 | -3.6 25.5 225 37 19 8.3 4.5
16000 -2.7 27.1 225 37 19 7.7 4.3 | -2.4 27.7 220 36 19 8.2 4.5
15500 -1.5 29.3 225 34 17 7.9 4.3 | -1.2 29.8 220 35 18 8.2 4.5
15000 -0.3 31.5 225 30 16 8.0 4.4 | -0.0 32.0 220 32 17 8.2 4.5
14500 0.9 33.6 225 27 14 8.3 4.6 | 1.2 34.2 215 30 15 8.4 4.6
14000 2.2 36.0 225 25 13 8.7 4.8 | 2.5 36.5 215 27 14 8.5 4.7
13500 3.5 38.3 225 24 12 8.7 4.8 | 3.7 38.7 210 25 13 8.6 4.7
13000 4.8 40.6 225 23 12 8.4 4.6 | 5.0 41.0 210 23 12 9.0 4.9
12500 6.1 43.0 220 22 11 8.4 4.6 | 6.4 43.5 205 22 11 9.0 4.9
12000 7.2 45.0 215 20 11 7.2 3.9 | 7.7 45.9 200 21 11 8.7 4.8
11500 8.2 46.8 210 19 10 7.4 4.1 | 9.0 48.2 200 20 10 9.0 4.9
11000 9.1 48.4 205 18 9 5.4 3.0 | 10.1 50.2 195 19 10 6.7 3.7
10500 9.9 49.8 195 17 9 5.4 2.9 | 11.1 52.0 190 18 10 9.1 5.0
10250 10.2 50.4 190 16 8 3.4 1.9 | 11.9 53.4 185 18 9 9.9 5.5
10000 10.4 50.7 190 16 8 4.1 2.3 | 12.5 54.5 180 17 9 7.0 3.8
9750 10.8 51.4 180 15 8 5.8 3.2 | 13.0 55.4 175 17 9 7.1 3.9
9500 11.1 52.0 175 15 8 5.4 3.0 | 13.5 56.3 170 16 8 7.0 3.8
9250 11.5 52.7 165 15 8 5.4 3.0 | 14.0 57.2 165 16 8 7.6 4.2
9000 11.9 53.4 160 16 8 6.7 3.7 | 14.6 58.3 165 16 8 9.3 5.1
8750 12.5 54.5 155 17 9 7.9 4.3 | 15.3 59.5 160 16 8 10.0 5.5
8500 13.1 55.6 150 17 9 7.3 4.0 | 16.0 60.8 155 16 8 9.9 5.5
8250 13.6 56.5 145 18 9 5.2 2.8 | 16.8 62.2 155 16 8 8.7 4.8
8000 14.0 57.2 140 18 9 5.4 3.0 | 17.4 63.3 150 17 9 9.1 5.0
7750 14.5 58.1 140 18 9 7.9 4.3 | 18.1 64.6 150 16 8 10.8 5.9
7500 15.1 59.2 140 17 9 7.6 4.1 | 18.9 66.0 150 16 8 10.1 5.6
7250 15.7 60.3 140 17 9 6.6 3.6 | 19.6 67.3 145 16 8 8.5 4.7
7000 16.1 61.0 140 16 8 6.9 3.8 | 20.2 68.4 145 16 8 8.6 4.7
6750 16.7 62.1 145 15 8 10.2 5.6 | 21.0 69.8 145 16 8 11.3 6.2
6500 17.6 63.7 145 14 7 11.2 6.1 | 21.9 71.4 145 16 8 11.9 6.5
6250 18.3 64.9 145 14 7 10.2 5.6 | 22.7 72.9 140 16 8 11.1 6.1
6000 19.1 66.4 145 13 7 9.8 5.4 | 23.5 74.3 140 16 8 10.8 5.9
5750 19.9 67.8 145 13 7 12.1 6.6 | 24.4 75.9 140 15 8 11.7 6.4
5500 21.0 69.8 145 11 6 20.6 11.3 | 25.5 77.9 140 14 7 21.8 12.0
06/30/2026 AT 1500 MDT | 06/30/2026 AT 1800 MDT
|
CAPE... +232.3 LI... -0.8 | CAPE... +217.5 LI... -0.5
CINH... -4.0 K INDEX... +22.9 | CINH... -37.3 K INDEX... +22.3
|
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 -60.2 -76.4 220 54 28 3.4 1.9 | -60.1 -76.2 220 48 25 2.1 1.2
45000 -55.6 -68.1 220 68 35 1.4 0.8 | -56.5 -69.7 220 65 34 2.6 1.4
40000 -53.3 -63.9 220 75 39 5.6 3.1 | -52.4 -62.3 215 74 38 6.0 3.3
38000 -50.0 -58.0 220 74 38 5.5 3.0 | -49.0 -56.2 215 73 38 5.6 3.1
36000 -46.7 -52.1 220 72 37 5.5 3.0 | -45.7 -50.3 215 73 38 5.6 3.1
34000 -43.0 -45.4 220 68 35 6.5 3.6 | -42.1 -43.8 220 71 36 6.0 3.3
32000 -38.6 -37.5 215 63 33 6.6 3.6 | -38.0 -36.4 220 67 34 6.1 3.3
30000 -34.2 -29.6 220 58 30 7.7 4.2 | -34.0 -29.2 220 62 32 7.0 3.8
29000 -31.9 -25.4 220 56 29 7.7 4.2 | -31.9 -25.4 220 59 30 7.0 3.8
28000 -29.6 -21.3 220 54 28 7.7 4.2 | -29.8 -21.6 220 56 29 7.1 3.9
27000 -27.3 -17.1 220 51 26 7.6 4.2 | -27.6 -17.7 220 53 27 7.6 4.2
26000 -25.1 -13.2 225 48 25 7.6 4.2 | -25.3 -13.5 220 48 25 7.6 4.2
25000 -22.8 -9.0 225 45 23 7.7 4.2 | -23.1 -9.6 220 44 23 7.7 4.2
24000 -20.6 -5.1 225 43 22 7.3 4.0 | -20.8 -5.4 220 42 22 8.0 4.4
23000 -18.5 -1.3 225 40 21 7.3 4.0 | -18.4 -1.1 225 42 21 8.0 4.4
22000 -16.3 2.7 225 38 20 7.3 4.0 | -16.0 3.2 225 41 21 8.1 4.4
21000 -14.1 6.6 225 36 19 7.7 4.2 | -13.7 7.3 225 39 20 7.9 4.3
20000 -11.8 10.8 225 34 18 7.7 4.2 | -11.4 11.5 225 37 19 7.9 4.3
19500 -10.7 12.7 225 34 17 7.7 4.2 | -10.2 13.6 225 36 19 8.0 4.4
19000 -9.6 14.7 225 33 17 8.0 4.4 | -8.4 16.9 225 35 18 9.2 5.0
18500 -7.8 18.0 220 31 16 8.2 4.5 | -7.1 19.2 225 34 17 9.1 5.0
18000 -6.6 20.1 220 31 16 8.7 4.8 | -5.8 21.6 225 33 17 9.1 5.0
17500 -5.3 22.5 215 30 15 9.2 5.0 | -4.4 24.1 220 32 16 9.2 5.0
17000 -3.9 25.0 215 29 15 9.2 5.0 | -3.1 26.4 220 31 16 9.2 5.0
16500 -2.5 27.5 215 29 15 9.6 5.3 | -1.7 28.9 220 30 16 9.5 5.2
16000 -1.1 30.0 210 28 14 9.6 5.3 | -0.3 31.5 220 29 15 9.4 5.2
15500 0.3 32.5 210 27 14 9.5 5.2 | 1.1 34.0 220 28 15 9.4 5.2
15000 1.7 35.1 210 27 14 9.4 5.2 | 2.5 36.5 220 28 14 9.4 5.2
14500 3.1 37.6 205 26 13 9.5 5.2 | 3.9 39.0 215 27 14 9.4 5.2
14000 4.5 40.1 205 25 13 9.5 5.2 | 5.3 41.5 215 26 13 9.5 5.2
13500 6.0 42.8 205 24 12 9.5 5.2 | 6.7 44.1 215 25 13 9.5 5.2
13000 7.4 45.3 200 23 12 9.4 5.2 | 8.1 46.6 215 24 12 9.4 5.2
12500 8.8 47.8 200 23 12 9.4 5.2 | 9.5 49.1 210 23 12 9.5 5.2
12000 10.2 50.4 200 22 12 9.6 5.3 | 10.9 51.6 210 22 12 9.2 5.0
11500 11.6 52.9 200 22 11 9.8 5.4 | 12.3 54.1 210 21 11 9.3 5.1
11000 13.0 55.4 200 22 11 8.4 4.6 | 13.6 56.5 210 21 11 8.5 4.6
10500 14.2 57.6 195 22 11 10.5 5.8 | 14.9 58.8 210 20 10 9.8 5.4
10250 15.1 59.2 195 21 11 12.4 6.8 | 15.7 60.3 205 19 10 11.5 6.3
10000 15.9 60.6 195 21 11 10.0 5.5 | 16.5 61.7 205 18 9 9.8 5.4
9750 16.7 62.1 195 21 11 9.6 5.3 | 17.2 63.0 205 18 9 9.1 5.0
9500 17.4 63.3 195 21 11 9.8 5.4 | 17.9 64.2 205 18 9 9.3 5.1
9250 18.1 64.6 195 21 11 9.2 5.1 | 18.6 65.5 205 18 9 9.1 5.0
9000 18.8 65.8 195 21 11 9.4 5.1 | 19.2 66.6 205 16 8 9.2 5.0
8750 19.5 67.1 195 21 11 10.1 5.6 | 19.9 67.8 205 15 8 9.5 5.2
8500 20.3 68.5 195 20 10 9.9 5.4 | 20.6 69.1 205 14 7 9.3 5.1
8250 21.0 69.8 195 20 10 10.2 5.6 | 21.3 70.3 205 14 7 9.8 5.4
8000 21.8 71.2 195 21 11 10.0 5.5 | 22.1 71.8 210 14 7 9.7 5.3
7750 22.5 72.5 195 20 10 9.5 5.2 | 22.7 72.9 210 13 7 9.1 5.0
7500 23.2 73.8 195 20 10 9.7 5.3 | 23.4 74.1 210 12 6 9.4 5.2
7250 23.9 75.0 195 19 10 9.1 5.0 | 24.1 75.4 210 11 5 8.8 4.8
7000 24.6 76.3 195 20 10 9.3 5.1 | 24.7 76.5 210 11 6 8.6 4.7
6750 25.3 77.5 195 20 10 10.7 5.9 | 25.4 77.7 210 11 5 9.6 5.3
6500 26.2 79.2 195 18 9 11.1 6.1 | 26.1 79.0 210 9 5 9.9 5.4
6250 27.0 80.6 190 18 9 11.1 6.1 | 26.9 80.4 210 8 4 10.1 5.5
6000 27.8 82.0 190 18 9 11.7 6.4 | 27.6 81.7 210 8 4 10.5 5.8
5750 28.7 83.7 190 18 9 9.4 5.1 | 28.4 83.1 210 8 4 8.6 4.7
5500 29.4 84.9 190 15 8 13.5 7.4 | 29.0 84.2 210 6 3 9.1 5.0
________________________________________________________________________________
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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