861
UXUS97 KBOU 061318
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
0717 MDT MONDAY, OCTOBER 6, 2025
THIS FORECAST IS FOR MONDAY, OCTOBER 6, 2025:
IF THE TRIGGER TEMPERATURE OF 54.9 F/12.7 C IS REACHED...THEN
THERMAL SOARING INDEX....................... POOR
MAXIMUM RATE OF LIFT........................ 0 FT/MIN (0.0 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 9384 FT MSL (4025 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 55.0 F/13.2 C
TIME OF TRIGGER TEMPERATURE.................... 1400 MDT
TIME OF OVERDEVELOPMENT........................ NONE
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... BROKEN/OVERCAST OPAQUE MIDDLE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 8020 FT MSL (2661 FT AGL)
THERMAL SOARING OUTLOOK FOR TUESDAY 10/07...... POOR
WAVE SOARING INDEX............................. GOOD
WAVE SOARING INDEX TREND (TO 1800 MDT).........
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... 12005 FT MSL (6646 FT AGL)
WEAK PVA/NVA (THROUGH 1800 MDT)................ NEITHER
POTENTIAL HEIGHT OF WAVE....................... 39815 FT MSL (34456 FT AGL)
WAVE SOARING OUTLOOK FOR TUESDAY 10/07......... POOR
REMARKS...
SUNRISE/SUNSET.................... 07:01:14 / 18:33:38 MDT
TOTAL POSSIBLE SUNSHINE........... 11 HR 32 MIN 24 SEC (692 MIN 24 SEC)
ALTITUDE OF SUN AT 12:47:26 MDT... 44.70 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 10/06/2025 AT 0600 MDT
FREEZING LEVEL.................. 10056 FT MSL (4697 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 10049 FT MSL (4690 FT AGL)
LIFTED CONDENSATION LEVEL....... 9568 FT MSL (4208 FT AGL)
LIFTED INDEX.................... +4.5
K INDEX......................... +14.3
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 -60.2 -76.4 250 54 28 1.6 0.9 94.4 202.0 47.3 M M
45000 -57.6 -71.7 245 61 31 2.6 1.4 75.8 168.4 38.9 M M
40000 -53.7 -64.7 240 69 36 2.6 1.4 59.2 138.5 30.6 M M
38000 -51.8 -61.2 240 69 36 3.3 1.8 53.0 127.4 27.3 M M
36000 -49.6 -57.3 240 67 35 3.3 1.8 46.8 116.3 23.8 M M
34000 -46.8 -52.2 240 65 34 6.0 3.3 42.5 108.5 21.3 M M
32000 -43.3 -45.9 245 63 32 6.0 3.3 39.3 102.8 19.5 M M
30000 -39.4 -38.9 245 58 30 7.2 3.9 36.8 98.2 18.1 M M
29000 -37.2 -35.0 245 54 28 7.2 3.9 35.7 96.3 17.5 M M
28000 -35.1 -31.2 245 50 26 7.2 3.9 34.8 94.6 17.0 M M
27000 -32.9 -27.2 245 48 25 7.9 4.4 33.9 93.1 16.5 M M
26000 -30.5 -22.9 245 47 24 7.9 4.3 33.1 91.6 16.1 M M
25000 -28.1 -18.6 240 47 24 7.9 4.3 32.5 90.4 15.8 M M
24000 -25.8 -14.4 240 47 24 7.4 4.0 31.8 89.3 15.4 M M
23000 -23.6 -10.5 240 46 24 7.3 4.0 30.8 87.5 14.8 M M
22000 -21.4 -6.5 245 46 24 7.4 4.0 30.0 86.0 14.2 M M
21000 -19.2 -2.6 245 45 23 7.5 4.1 29.2 84.6 13.7 M M
20000 -16.4 2.5 240 44 23 7.5 4.1 28.1 82.7 13.0 M M
19500 -15.3 4.5 240 44 23 7.5 4.1 27.8 82.0 12.7 M M
19000 -14.2 6.4 240 43 22 7.5 4.1 27.4 81.4 12.5 M M
18500 -13.1 8.4 240 43 22 7.3 4.0 27.0 80.6 12.2 M M
18000 -12.0 10.4 240 43 22 7.3 4.0 26.6 79.9 11.9 M M
17500 -11.0 12.2 240 42 22 7.2 4.0 26.2 79.1 11.6 M M
17000 -9.9 14.2 240 42 22 7.2 4.0 25.7 78.3 11.2 M M
16500 -8.8 16.2 240 42 21 7.2 3.9 25.3 77.6 10.9 M M
16000 -7.8 18.0 240 41 21 7.1 3.9 24.9 76.8 10.5 M M
15500 -6.7 19.9 240 40 21 7.1 3.9 24.4 76.0 10.2 M M
15000 -5.8 21.6 240 39 20 6.5 3.5 23.9 75.0 9.7 M M
14500 -4.8 23.4 240 38 19 6.7 3.7 23.4 74.1 9.3 M M
14000 -4.0 24.8 240 36 19 5.1 2.8 22.7 72.9 8.7 M M
13500 -3.3 26.1 240 34 18 5.4 2.9 22.0 71.6 8.0 M M
13000 -2.7 27.1 240 32 17 3.4 1.9 21.2 70.1 7.2 M M
12500 -2.3 27.9 240 30 15 3.2 1.8 20.1 68.2 6.1 M M
12000 -1.9 28.6 235 27 14 2.6 1.4 19.0 66.2 5.1 M M
11500 -1.6 29.1 230 23 12 2.4 1.3 17.8 64.1 3.9 M M
11000 -1.2 29.8 225 20 10 4.4 2.4 16.7 62.1 2.9 M M
10500 -0.5 31.1 220 16 8 5.3 2.9 16.0 60.8 2.2 M M
10250 -0.2 31.6 215 14 7 3.5 1.9 15.6 60.1 1.8 M M
10000 0.0 32.0 215 14 7 2.5 1.4 15.0 59.0 1.2 M M
9750 0.3 32.5 210 12 6 3.8 2.1 14.5 58.1 0.8 M M
9500 0.5 32.9 205 10 5 4.0 2.2 14.0 57.3 0.3 M M
9250 0.8 33.4 190 8 4 2.8 1.5 13.6 56.4 -0.2 277 1.4
9000 0.9 33.6 185 7 4 1.5 0.8 13.0 55.3 -0.8 266 1.3
8750 1.1 34.0 175 6 3 2.6 1.4 12.4 54.2 -1.3 254 1.3
8500 1.3 34.3 165 6 3 3.2 1.8 11.8 53.3 -1.8 240 1.2
8250 1.5 34.7 150 6 3 2.8 1.6 11.3 52.4 -2.4 226 1.1
8000 1.7 35.1 150 6 3 2.7 1.5 10.8 51.4 -2.9 212 1.1
7750 1.9 35.4 145 6 3 2.6 1.4 10.2 50.4 -3.4 199 1.0
7500 2.1 35.8 125 6 3 2.2 1.2 9.7 49.4 -4.0 186 0.9
7250 2.3 36.1 120 7 4 2.4 1.3 9.1 48.4 -4.6 174 0.9
7000 2.4 36.3 115 7 4 0.9 0.5 8.5 47.3 -5.2 162 0.8
6750 2.6 36.7 115 8 4 6.4 3.5 7.9 46.3 -5.8 150 0.8
6500 3.3 37.9 105 7 4 9.3 5.1 7.9 46.3 -5.8 122 0.6
6250 3.8 38.8 105 7 4 6.3 3.4 7.7 45.9 -6.0 99 0.5
6000 4.3 39.7 105 7 4 6.5 3.5 7.5 45.5 -6.3 77 0.4
5750 4.8 40.6 100 7 4 8.7 4.8 7.3 45.1 -6.5 55 0.3
5500 5.6 42.1 100 6 3 14.6 8.0 7.4 45.4 -6.4 22 0.1
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
10/06/2025 AT 0900 MDT | 10/06/2025 AT 1200 MDT
|
CAPE... 0.0 LI... +2.9 | CAPE... +2.8 LI... +3.8
CINH... -0.3 K INDEX... +12.9 | CINH... -0.1 K INDEX... +12.2
|
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 -59.9 -75.8 255 49 25 1.4 0.8 | -59.7 -75.5 255 46 24 1.1 0.6
45000 -57.5 -71.5 245 58 30 2.7 1.5 | -57.6 -71.7 245 60 31 3.1 1.7
40000 -53.4 -64.1 245 69 36 2.8 1.5 | -52.7 -62.9 245 73 38 3.1 1.7
38000 -51.4 -60.5 245 70 36 3.0 1.6 | -51.1 -60.0 245 73 37 2.7 1.5
36000 -49.6 -57.3 240 70 36 3.0 1.7 | -49.4 -56.9 240 72 37 2.7 1.5
34000 -46.8 -52.2 240 68 35 6.4 3.5 | -46.7 -52.1 240 70 36 6.6 3.6
32000 -43.0 -45.4 240 65 34 6.4 3.5 | -42.7 -44.9 240 67 35 6.6 3.6
30000 -39.0 -38.2 240 60 31 7.0 3.9 | -38.6 -37.5 240 63 33 7.0 3.9
29000 -36.9 -34.4 240 56 29 7.0 3.9 | -36.5 -33.7 240 60 31 7.0 3.9
28000 -34.8 -30.6 240 51 27 7.0 3.9 | -34.4 -29.9 235 58 30 7.0 3.9
27000 -32.6 -26.7 240 48 25 7.4 4.1 | -32.3 -26.1 235 56 29 7.0 3.8
26000 -30.4 -22.7 240 48 25 7.4 4.0 | -30.2 -22.4 235 55 28 7.0 3.8
25000 -28.2 -18.8 240 47 24 7.4 4.0 | -28.1 -18.6 235 55 28 7.0 3.8
24000 -26.0 -14.8 240 46 24 7.3 4.0 | -26.0 -14.8 235 54 28 7.7 4.2
23000 -23.8 -10.8 240 45 23 7.4 4.0 | -23.7 -10.7 235 52 27 7.7 4.2
22000 -21.6 -6.9 240 44 22 7.4 4.0 | -20.8 -5.4 235 50 26 7.7 4.2
21000 -18.8 -1.8 240 42 22 7.6 4.2 | -18.5 -1.3 235 47 24 7.6 4.2
20000 -16.6 2.1 240 41 21 7.6 4.2 | -16.3 2.7 235 45 23 7.6 4.2
19500 -15.4 4.3 240 40 21 7.6 4.2 | -15.1 4.8 235 44 22 7.6 4.2
19000 -14.3 6.3 235 40 21 7.5 4.1 | -14.0 6.8 235 42 22 7.4 4.1
18500 -13.2 8.2 240 39 20 7.3 4.0 | -12.9 8.8 235 41 21 7.1 3.9
18000 -12.1 10.2 240 39 20 7.4 4.0 | -11.9 10.6 235 40 20 7.1 3.9
17500 -11.1 12.0 240 38 20 6.8 3.7 | -10.9 12.4 235 38 20 6.8 3.7
17000 -10.0 14.0 240 37 19 6.8 3.7 | -9.8 14.4 240 37 19 6.8 3.7
16500 -9.0 15.8 240 36 19 6.6 3.6 | -8.8 16.2 240 35 18 6.6 3.6
16000 -8.1 17.4 245 35 18 6.5 3.6 | -7.9 17.8 245 33 17 6.5 3.6
15500 -7.1 19.2 245 34 17 6.4 3.5 | -6.9 19.6 245 32 16 6.4 3.5
15000 -6.2 20.8 245 32 17 6.1 3.3 | -6.0 21.2 250 30 15 5.9 3.2
14500 -5.4 22.3 250 31 16 6.2 3.4 | -5.2 22.6 250 28 14 6.0 3.3
14000 -4.5 23.9 250 29 15 5.3 2.9 | -4.4 24.1 255 25 13 5.0 2.8
13500 -3.8 25.2 255 27 14 5.6 3.1 | -3.6 25.5 255 23 12 5.3 2.9
13000 -3.1 26.4 255 25 13 3.8 2.1 | -3.0 26.6 260 20 10 3.9 2.1
12500 -2.6 27.3 255 23 12 3.9 2.1 | -2.5 27.5 260 17 9 4.0 2.2
12000 -2.2 28.0 250 20 10 2.6 1.4 | -2.1 28.2 260 14 7 2.0 1.1
11500 -1.9 28.6 245 17 9 2.3 1.3 | -1.9 28.6 255 11 5 1.6 0.9
11000 -1.5 29.3 240 13 7 4.8 2.6 | -1.6 29.1 245 8 4 3.9 2.1
10500 -0.8 30.6 230 10 5 5.4 3.0 | -1.0 30.2 225 6 3 5.3 2.9
10250 -0.4 31.3 225 8 4 4.0 2.2 | -0.8 30.6 205 5 3 -0.1 -0.0
10000 -0.2 31.6 220 8 4 2.8 1.5 | -0.9 30.4 200 5 2 1.6 0.9
9750 0.0 32.0 210 7 3 3.6 2.0 | -0.4 31.3 190 5 2 9.2 5.0
9500 0.3 32.5 205 6 3 3.8 2.1 | 0.2 32.4 180 5 3 9.2 5.1
9250 0.5 32.9 190 5 3 2.7 1.5 | 0.9 33.6 175 5 3 5.9 3.3
9000 0.7 33.3 185 4 2 2.0 1.1 | 1.1 34.0 175 6 3 2.4 1.3
8750 0.9 33.6 175 4 2 3.5 1.9 | 1.3 34.3 175 6 3 3.9 2.1
8500 1.2 34.2 165 5 3 4.0 2.2 | 1.6 34.9 170 6 3 3.8 2.1
8250 1.4 34.5 160 6 3 3.5 1.9 | 1.9 35.4 170 6 3 3.1 1.7
8000 1.7 35.1 160 7 4 3.4 1.9 | 2.0 35.6 170 7 3 2.3 1.3
7750 1.9 35.4 160 8 4 3.0 1.6 | 2.3 36.1 170 7 3 4.8 2.6
7500 2.1 35.8 145 8 4 2.2 1.2 | 2.7 36.9 155 6 3 4.4 2.4
7250 2.3 36.1 140 8 4 2.6 1.4 | 2.9 37.2 145 5 3 2.4 1.3
7000 2.5 36.5 140 8 4 1.0 0.6 | 3.0 37.4 140 5 3 0.0 0.0
6750 2.6 36.7 140 8 4 6.8 3.7 | 3.1 37.6 130 5 2 9.2 5.0
6500 3.4 38.1 125 6 3 9.9 5.4 | 4.2 39.6 105 4 2 13.0 7.1
6250 3.9 39.0 120 6 3 7.0 3.8 | 4.8 40.6 100 4 2 7.2 3.9
6000 4.4 39.9 115 5 3 6.1 3.3 | 5.4 41.7 095 4 2 7.2 4.0
5750 4.8 40.6 105 5 3 6.4 3.5 | 5.9 42.6 085 4 2 7.1 3.9
5500 5.6 42.1 100 5 2 13.8 7.6 | 6.6 43.9 075 4 2 14.4 7.9
10/06/2025 AT 1500 MDT | 10/06/2025 AT 1800 MDT
|
CAPE... +10.0 LI... +1.2 | CAPE... +7.8 LI... +0.9
CINH... -0.2 K INDEX... +20.4 | CINH... -0.1 K INDEX... +25.3
|
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 -60.1 -76.2 255 45 23 1.0 0.6 | -59.9 -75.8 260 39 20 1.1 0.6
45000 -57.9 -72.2 250 59 30 3.5 1.9 | -57.2 -71.0 260 51 26 5.1 2.8
40000 -52.7 -62.9 245 68 35 3.5 1.9 | -49.5 -57.1 255 58 30 5.4 3.0
38000 -50.8 -59.4 245 70 36 3.1 1.7 | -48.1 -54.6 255 64 33 1.9 1.0
36000 -48.9 -56.0 245 71 37 3.1 1.7 | -47.0 -52.6 250 70 36 1.9 1.0
34000 -46.3 -51.3 240 71 37 6.2 3.4 | -45.2 -49.4 250 75 39 4.6 2.5
32000 -42.6 -44.7 240 69 36 6.2 3.4 | -42.2 -44.0 245 78 40 4.5 2.5
30000 -38.1 -36.6 240 65 34 7.4 4.0 | -39.0 -38.2 245 76 39 6.2 3.4
29000 -35.9 -32.6 240 63 32 7.4 4.0 | -37.2 -35.0 245 72 37 6.2 3.4
28000 -33.7 -28.7 235 61 31 7.4 4.0 | -35.4 -31.7 245 67 35 6.2 3.4
27000 -31.5 -24.7 235 59 30 7.1 3.9 | -33.5 -28.3 245 63 32 6.5 3.6
26000 -29.4 -20.9 235 57 29 7.1 3.9 | -31.5 -24.7 245 59 30 6.5 3.6
25000 -27.3 -17.1 235 55 28 7.1 3.9 | -29.6 -21.3 245 54 28 6.5 3.6
24000 -25.2 -13.4 235 54 28 6.8 3.7 | -27.6 -17.7 240 50 26 8.2 4.5
23000 -23.2 -9.8 235 52 27 6.9 3.8 | -25.2 -13.4 240 46 24 8.1 4.4
22000 -21.1 -6.0 240 50 26 6.9 3.8 | -22.8 -9.0 240 42 22 8.1 4.5
21000 -19.2 -2.6 240 47 24 6.0 3.3 | -20.4 -4.7 240 38 20 7.8 4.3
20000 -17.4 0.7 240 45 23 6.1 3.4 | -18.1 -0.6 240 35 18 7.9 4.3
19500 -16.5 2.3 240 43 22 6.2 3.4 | -17.0 1.4 240 33 17 7.9 4.3
19000 -15.6 3.9 245 42 21 6.1 3.4 | -15.8 3.6 240 32 16 8.0 4.4
18500 -14.7 5.5 245 40 21 6.8 3.8 | -14.2 6.4 240 29 15 7.6 4.1
18000 -13.2 8.2 245 37 19 6.8 3.7 | -13.1 8.4 240 28 14 7.6 4.2
17500 -12.2 10.0 245 34 18 7.2 3.9 | -12.0 10.4 240 27 14 7.1 3.9
17000 -11.2 11.8 250 32 16 7.1 3.9 | -11.0 12.2 240 26 13 7.2 3.9
16500 -10.1 13.8 250 30 15 7.3 4.0 | -9.9 14.2 240 25 13 7.2 4.0
16000 -9.0 15.8 250 27 14 7.4 4.1 | -8.9 16.0 240 23 12 7.2 4.0
15500 -8.0 17.6 250 25 13 7.4 4.1 | -7.8 18.0 240 22 12 7.2 4.0
15000 -6.9 19.6 250 23 12 7.3 4.0 | -6.7 19.9 235 21 11 7.2 4.0
14500 -5.8 21.6 250 21 11 7.3 4.0 | -5.7 21.7 235 20 10 7.3 4.0
14000 -4.9 23.2 250 19 10 6.4 3.5 | -4.7 23.5 235 19 10 6.5 3.6
13500 -3.9 25.0 250 17 9 6.6 3.6 | -3.7 25.3 230 17 9 6.8 3.7
13000 -3.1 26.4 245 14 7 5.0 2.8 | -2.9 26.8 225 16 8 4.9 2.7
12500 -2.4 27.7 240 12 6 5.2 2.9 | -2.2 28.0 220 13 7 5.1 2.8
12000 -1.7 28.9 235 10 5 3.6 2.0 | -1.5 29.3 210 12 6 4.1 2.2
11500 -1.2 29.8 225 8 4 3.6 2.0 | -0.9 30.4 200 10 5 4.1 2.3
11000 -0.8 30.6 205 6 3 2.4 1.3 | -0.4 31.3 190 9 5 3.4 1.9
10500 -0.5 31.1 180 6 3 2.8 1.6 | 0.1 32.2 180 9 5 4.2 2.3
10250 -0.3 31.5 170 7 3 -0.0 -0.0 | 0.3 32.5 175 10 5 0.3 0.2
10000 -0.3 31.5 175 7 4 3.3 1.8 | 0.2 32.4 175 10 5 2.6 1.4
9750 0.2 32.4 170 7 4 8.4 4.6 | 0.7 33.3 170 10 5 8.1 4.4
9500 0.7 33.3 160 7 4 7.6 4.2 | 1.2 34.2 165 9 5 6.8 3.7
9250 1.2 34.2 150 8 4 5.7 3.1 | 1.7 35.1 160 9 5 6.3 3.4
9000 1.5 34.7 150 8 4 4.5 2.4 | 2.1 35.8 160 9 5 5.3 2.9
8750 1.9 35.4 145 8 4 7.1 3.9 | 2.5 36.5 155 8 4 5.9 3.2
8500 2.4 36.3 140 6 3 6.7 3.7 | 2.9 37.2 145 6 3 5.4 3.0
8250 2.8 37.0 135 5 3 3.0 1.6 | 3.3 37.9 135 5 3 3.4 1.9
8000 2.9 37.2 120 5 3 1.1 0.6 | 3.4 38.1 125 4 2 2.4 1.3
7750 3.2 37.8 100 5 2 7.1 3.9 | 3.6 38.5 105 4 2 2.4 1.3
7500 3.8 38.8 085 4 2 7.1 3.9 | 3.8 38.8 070 4 2 2.3 1.3
7250 4.1 39.4 065 4 2 3.0 1.6 | 4.0 39.2 055 4 2 3.2 1.8
7000 4.3 39.7 055 5 3 1.6 0.9 | 4.2 39.6 050 5 3 1.6 0.9
6750 4.6 40.3 045 6 3 11.4 6.3 | 4.4 39.9 040 6 3 9.7 5.3
6500 5.8 42.4 050 6 3 13.8 7.6 | 5.4 41.7 045 6 3 12.4 6.8
6250 6.4 43.5 045 6 3 7.0 3.9 | 6.0 42.8 040 6 3 6.8 3.8
6000 7.0 44.6 035 6 3 7.7 4.2 | 6.6 43.9 040 6 3 8.4 4.6
5750 7.6 45.7 030 7 3 11.7 6.4 | 7.2 45.0 040 6 3 7.7 4.2
5500 8.8 47.8 035 6 3 22.4 12.3 | 7.7 45.9 030 6 3 9.0 4.9
________________________________________________________________________________
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.
042613
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page