469
UXUS97 KBOU 131311
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
0711 MDT THURSDAY, MARCH 13, 2025
THIS FORECAST IS FOR THURSDAY, MARCH 13, 2025:
IF THE TRIGGER TEMPERATURE OF 55.9 F/13.3 C IS REACHED...THEN
THERMAL SOARING INDEX....................... GOOD
MAXIMUM RATE OF LIFT........................ 748 FT/MIN (3.8 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 14926 FT MSL (9629 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 69.0 F/21.0 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................. 13211 FT MSL (7914 FT AGL)
THERMAL SOARING OUTLOOK FOR FRIDAY 03/14....... POOR
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1800 MDT).........
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1800 MDT)................ NEITHER
POTENTIAL HEIGHT OF WAVE....................... 17605 FT MSL (12308 FT AGL)
WAVE SOARING OUTLOOK FOR FRIDAY 03/14.......... POOR
REMARKS...
SUNRISE/SUNSET.................... 07:13:05 / 19:04:27 MDT
TOTAL POSSIBLE SUNSHINE........... 11 HR 51 MIN 22 SEC (711 MIN 22 SEC)
ALTITUDE OF SUN AT 13:08:46 MDT... 47.58 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 03/13/2025 AT 0600 MDT
FREEZING LEVEL.................. 10159 FT MSL (4862 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 17496 FT MSL (12199 FT AGL)
LIFTED CONDENSATION LEVEL....... 16523 FT MSL (11226 FT AGL)
LIFTED INDEX.................... +1.2
K INDEX......................... -3.4
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 -61.0 -77.8 260 47 24 0.6 0.4 M M M M M
45000 -59.9 -75.8 255 67 35 0.6 0.3 M M M M M
40000 -59.2 -74.6 255 68 35 0.5 0.3 M M M M M
38000 -58.1 -72.6 255 65 33 3.4 1.9 M M M M M
36000 -56.1 -69.0 250 59 31 3.4 1.9 M M M M M
34000 -53.8 -64.8 250 54 28 8.3 4.5 M M M M M
32000 -48.0 -54.4 250 52 27 8.7 4.8 M M M M M
30000 -42.8 -45.0 250 49 25 7.9 4.3 32.9 91.3 9.3 M M
29000 -40.4 -40.7 250 48 24 7.9 4.4 32.1 89.8 8.8 M M
28000 -38.1 -36.6 250 46 24 7.9 4.4 31.5 88.6 8.4 M M
27000 -35.7 -32.3 250 44 23 7.7 4.2 30.9 87.6 8.1 M M
26000 -33.6 -28.5 245 41 21 6.9 3.8 29.8 85.6 7.3 M M
25000 -31.5 -24.7 240 38 20 6.9 3.8 28.7 83.6 6.5 M M
24000 -29.4 -20.9 235 35 18 6.9 3.8 27.7 81.9 5.8 M M
23000 -26.9 -16.4 235 35 18 8.6 4.7 27.1 80.8 5.4 M M
22000 -24.3 -11.7 240 35 18 8.6 4.7 26.7 80.1 5.1 M M
21000 -21.8 -7.2 240 36 18 8.5 4.6 26.4 79.5 4.9 M M
20000 -19.3 -2.7 235 35 18 8.1 4.4 25.8 78.4 4.4 M M
19500 -18.1 -0.6 235 34 18 8.1 4.4 25.5 77.8 4.2 M M
19000 -16.9 1.6 230 34 17 8.1 4.4 25.2 77.3 4.0 M M
18500 -15.7 3.7 230 33 17 8.0 4.4 24.9 76.9 3.8 M M
18000 -14.6 5.7 225 34 17 6.6 3.6 24.5 76.1 3.4 M M
17500 -13.6 7.5 220 34 18 6.7 3.7 24.0 75.2 3.0 M M
17000 -12.6 9.3 220 35 18 6.7 3.7 23.5 74.2 2.5 M M
16500 -11.6 11.1 220 34 18 6.7 3.7 22.9 73.3 2.1 M M
16000 -10.2 13.6 215 33 17 5.5 3.0 22.1 71.8 1.3 M M
15500 -9.4 15.1 215 31 16 5.3 2.9 21.3 70.4 0.6 M M
15000 -8.6 16.5 215 29 15 4.6 2.5 20.6 69.1 -0.0 746 3.8
14500 -8.1 17.4 215 26 13 3.9 2.2 19.6 67.3 -1.0 715 3.6
14000 -7.5 18.5 215 23 12 4.2 2.3 18.7 65.6 -1.9 684 3.5
13500 -6.8 19.8 210 19 10 5.1 2.8 17.8 64.1 -2.7 648 3.3
13000 -6.1 21.0 210 15 8 5.4 2.9 17.1 62.8 -3.4 612 3.1
12500 -5.1 22.8 210 13 6 7.8 4.3 16.6 61.9 -3.9 567 2.9
12000 -4.0 24.8 210 10 5 7.6 4.2 16.3 61.3 -4.3 519 2.6
11500 -2.8 27.0 220 9 5 8.5 4.7 16.0 60.8 -4.6 468 2.4
11000 -1.5 29.3 235 10 5 8.4 4.6 15.8 60.4 -4.8 416 2.1
10500 -0.5 31.1 245 12 6 5.6 3.1 15.3 59.6 -5.3 371 1.9
10250 -0.1 31.8 250 13 7 6.0 3.3 15.0 59.0 -5.6 351 1.8
10000 0.3 32.5 250 15 8 6.1 3.4 14.7 58.5 -5.9 330 1.7
9750 0.7 33.3 255 17 9 5.4 3.0 14.4 58.0 -6.3 310 1.6
9500 1.1 34.0 255 17 9 4.8 2.6 14.0 57.3 -6.7 292 1.5
9250 1.5 34.7 255 17 9 5.0 2.7 13.7 56.6 -7.1 274 1.4
9000 1.8 35.2 255 17 9 4.8 2.6 13.3 55.9 -7.4 256 1.3
8750 2.2 36.0 255 17 9 6.5 3.6 12.9 55.3 -7.8 237 1.2
8500 2.8 37.0 255 16 8 8.1 4.4 12.8 55.0 -8.0 213 1.1
8250 3.3 37.9 255 15 8 7.1 3.9 12.6 54.7 -8.2 188 1.0
8000 3.9 39.0 250 15 8 9.5 5.2 12.5 54.4 -8.3 164 0.8
7750 4.7 40.5 250 13 7 10.3 5.6 12.5 54.6 -8.3 132 0.7
7500 5.4 41.7 245 12 6 8.5 4.6 12.5 54.5 -8.4 105 0.5
7250 6.1 43.0 245 11 6 9.0 5.0 12.4 54.3 -8.4 77 0.4
7000 6.8 44.2 240 10 5 10.0 5.5 12.4 54.3 -8.5 48 0.2
6750 7.5 45.5 240 10 5 8.9 4.9 12.4 54.3 -8.5 18 0.1
6500 8.2 46.8 235 9 5 11.1 6.1 12.3 54.2 -8.6 M M
6250 8.9 48.0 230 9 5 0.1 0.0 12.3 54.1 -8.6 M M
6000 8.3 46.9 220 8 4 -9.0 -4.9 10.9 51.7 -10.0 M M
5750 7.5 45.5 210 8 4 -16.8 -9.2 9.5 49.0 -11.5 M M
5500 4.9 40.8 200 9 4 -54.3 -29.8 6.2 43.1 -14.9 60 0.3
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
03/13/2025 AT 0900 MDT | 03/13/2025 AT 1200 MDT
|
CAPE... 0.0 LI... +5.8 | CAPE... 0.0 LI... +4.5
CINH... 0.0 K INDEX... -4.3 | CINH... 0.0 K INDEX... -3.5
|
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 -58.8 -73.8 255 47 24 1.2 0.7 | -57.8 -72.0 260 48 24 2.1 1.1
45000 -56.9 -70.4 250 71 37 1.2 0.7 | -54.5 -66.1 250 72 37 2.7 1.5
40000 -59.3 -74.7 250 75 38 -1.7 -0.9 | -58.2 -72.8 245 74 38 -2.7 -1.5
38000 -59.0 -74.2 250 72 37 4.0 2.2 | -58.6 -73.5 240 74 38 3.1 1.7
36000 -56.6 -69.9 240 66 34 4.0 2.2 | -56.7 -70.1 235 71 37 3.1 1.7
34000 -54.1 -65.4 235 60 31 7.1 3.9 | -54.9 -66.8 230 70 36 5.6 3.1
32000 -48.5 -55.3 235 58 30 8.4 4.6 | -49.0 -56.2 230 68 35 8.7 4.8
30000 -43.4 -46.1 235 57 29 8.2 4.5 | -43.9 -47.0 230 65 34 7.8 4.3
29000 -41.0 -41.8 240 55 28 8.2 4.5 | -41.5 -42.7 230 64 33 7.9 4.3
28000 -38.5 -37.3 240 53 27 8.2 4.5 | -39.1 -38.4 230 62 32 7.9 4.3
27000 -36.0 -32.8 240 51 26 8.2 4.5 | -36.8 -34.2 235 61 31 7.9 4.3
26000 -33.7 -28.7 240 49 25 7.6 4.1 | -34.4 -29.9 235 57 29 7.7 4.2
25000 -31.4 -24.5 235 46 24 7.6 4.1 | -32.1 -25.8 235 53 27 7.7 4.2
24000 -29.2 -20.6 235 44 23 7.6 4.2 | -29.8 -21.6 235 49 25 7.8 4.3
23000 -27.1 -16.8 230 42 22 6.8 3.7 | -27.7 -17.9 235 46 24 6.8 3.8
22000 -25.0 -13.0 230 40 21 6.8 3.7 | -25.6 -14.1 235 44 23 6.9 3.8
21000 -23.0 -9.4 230 38 19 7.0 3.9 | -23.6 -10.5 235 42 22 6.9 3.8
20000 -20.6 -5.1 230 36 19 8.1 4.5 | -21.3 -6.3 235 39 20 7.6 4.2
19500 -19.4 -2.9 230 36 18 8.1 4.5 | -20.2 -4.4 235 37 19 7.6 4.2
19000 -18.2 -0.8 230 35 18 8.1 4.5 | -19.0 -2.2 235 35 18 7.6 4.2
18500 -17.0 1.4 230 34 18 8.3 4.6 | -17.9 -0.2 235 33 17 7.6 4.2
18000 -15.9 3.4 230 33 17 5.9 3.3 | -16.7 1.9 235 32 16 7.8 4.3
17500 -15.0 5.0 230 32 17 6.2 3.4 | -15.6 3.9 230 31 16 7.8 4.3
17000 -14.1 6.6 225 31 16 6.1 3.3 | -13.9 7.0 225 29 15 6.5 3.5
16500 -12.7 9.1 220 30 15 6.0 3.3 | -12.9 8.8 220 29 15 6.5 3.6
16000 -11.8 10.8 220 28 15 6.9 3.8 | -12.0 10.4 215 28 15 6.1 3.4
15500 -10.8 12.6 215 27 14 7.1 3.9 | -11.1 12.0 215 27 14 5.8 3.2
15000 -9.7 14.5 215 25 13 6.9 3.8 | -10.2 13.6 210 25 13 5.9 3.3
14500 -8.7 16.3 215 23 12 6.7 3.7 | -9.3 15.3 205 23 12 6.3 3.5
14000 -7.7 18.1 215 21 11 6.5 3.6 | -8.4 16.9 205 20 10 6.3 3.5
13500 -6.8 19.8 220 17 9 5.8 3.2 | -7.5 18.5 205 17 9 6.1 3.4
13000 -6.0 21.2 225 12 6 5.9 3.3 | -6.6 20.1 200 12 6 6.1 3.3
12500 -5.0 23.0 235 9 5 7.1 3.9 | -5.6 21.9 195 9 5 7.4 4.0
12000 -4.0 24.8 240 7 3 7.0 3.8 | -4.5 23.9 190 6 3 7.2 3.9
11500 -2.9 26.8 250 6 3 7.7 4.2 | -3.4 25.9 200 4 2 8.2 4.5
11000 -1.8 28.8 255 7 4 7.7 4.2 | -2.2 28.0 225 4 2 8.4 4.6
10500 -0.8 30.6 255 8 4 5.6 3.1 | -1.1 30.0 245 5 3 6.2 3.4
10250 -0.4 31.3 255 9 5 6.0 3.3 | -0.7 30.7 250 6 3 6.4 3.5
10000 0.1 32.2 255 10 5 7.2 4.0 | -0.2 31.6 255 7 3 7.3 4.0
9750 0.6 33.1 255 11 6 6.9 3.8 | 0.3 32.5 260 7 3 6.5 3.6
9500 1.0 33.8 260 11 6 5.7 3.1 | 0.7 33.3 255 5 2 5.2 2.8
9250 1.5 34.7 260 11 6 6.7 3.7 | 1.1 34.0 235 3 2 5.9 3.2
9000 1.9 35.4 265 12 6 4.0 2.2 | 1.5 34.7 190 2 1 4.5 2.5
8750 2.1 35.8 260 12 6 3.6 2.0 | 1.8 35.2 155 3 1 6.2 3.4
8500 2.5 36.5 260 10 5 6.2 3.4 | 2.5 36.5 145 3 2 9.0 4.9
8250 2.9 37.2 260 8 4 4.7 2.6 | 3.1 37.6 140 4 2 7.6 4.2
8000 3.3 37.9 260 7 3 8.1 4.5 | 3.7 38.7 140 4 2 10.4 5.7
7750 4.0 39.2 250 5 3 9.0 4.9 | 4.5 40.1 135 4 2 10.8 5.9
7500 4.5 40.1 240 4 2 6.3 3.5 | 5.2 41.4 135 4 2 8.5 4.7
7250 5.0 41.0 225 3 2 7.3 4.0 | 5.9 42.6 135 4 2 8.9 4.9
7000 5.7 42.3 210 3 2 10.1 5.6 | 6.5 43.7 135 4 2 9.8 5.4
6750 6.5 43.7 200 3 2 9.7 5.3 | 7.3 45.1 140 4 2 10.5 5.8
6500 7.1 44.8 190 4 2 9.8 5.4 | 8.1 46.6 140 4 2 10.0 5.5
6250 7.8 46.0 185 4 2 3.2 1.7 | 8.8 47.8 140 4 2 10.2 5.6
6000 7.6 45.7 190 5 3 -3.8 -2.1 | 9.6 49.3 140 4 2 11.3 6.2
5750 7.2 45.0 190 6 3 -9.1 -5.0 | 10.4 50.7 140 4 2 9.2 5.0
5500 6.0 42.8 195 7 4 -22.2 -12.2 | 11.1 52.0 140 3 2 12.0 6.6
03/13/2025 AT 1500 MDT | 03/13/2025 AT 1800 MDT
|
CAPE... 0.0 LI... +1.7 | CAPE... +14.5 LI... -0.5
CINH... 0.0 K INDEX... +7.4 | CINH... -39.6 K INDEX... +17.4
|
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 -57.0 -70.6 260 39 20 1.4 0.8 | -57.2 -71.0 255 37 19 2.8 1.5
45000 -54.8 -66.6 250 64 33 1.7 0.9 | -52.8 -63.0 245 51 26 3.0 1.7
40000 -56.4 -69.5 235 70 36 -1.3 -0.7 | -53.5 -64.3 230 64 33 -0.7 -0.4
38000 -56.5 -69.7 235 72 37 2.4 1.3 | -53.8 -64.8 225 68 35 0.3 0.2
36000 -55.0 -67.0 235 72 37 2.5 1.4 | -53.6 -64.5 230 63 32 0.3 0.2
34000 -53.5 -64.3 235 71 37 2.8 1.6 | -53.4 -64.1 230 58 30 -0.2 -0.1
32000 -49.6 -57.3 230 66 34 6.0 3.3 | -50.7 -59.3 230 55 28 5.2 2.9
30000 -45.9 -50.6 225 61 31 8.3 4.5 | -47.2 -53.0 225 52 27 6.8 3.7
29000 -43.4 -46.1 225 59 30 8.5 4.7 | -44.7 -48.5 225 51 26 8.2 4.5
28000 -40.8 -41.4 225 57 29 8.5 4.7 | -42.3 -44.1 220 49 25 8.2 4.5
27000 -38.3 -36.9 230 55 28 8.6 4.7 | -39.8 -39.6 220 48 25 8.2 4.5
26000 -35.7 -32.3 230 54 28 8.4 4.6 | -37.4 -35.3 220 48 25 8.1 4.4
25000 -33.2 -27.8 230 53 27 8.4 4.6 | -34.9 -30.8 225 48 25 8.1 4.4
24000 -30.7 -23.3 230 53 27 8.4 4.6 | -32.5 -26.5 225 48 25 8.1 4.4
23000 -28.4 -19.1 230 51 26 7.3 4.0 | -30.2 -22.4 230 48 25 7.7 4.2
22000 -26.2 -15.2 230 49 25 7.3 4.0 | -27.9 -18.2 230 47 24 7.7 4.2
21000 -24.0 -11.2 230 46 24 7.3 4.0 | -25.6 -14.1 235 46 24 7.7 4.2
20000 -22.0 -7.6 235 43 22 6.6 3.6 | -23.4 -10.1 235 44 23 6.9 3.8
19500 -21.0 -5.8 235 41 21 6.6 3.6 | -22.4 -8.3 235 42 22 6.9 3.8
19000 -20.0 -4.0 235 39 20 6.6 3.6 | -21.4 -6.5 235 40 21 6.9 3.8
18500 -19.1 -2.4 240 37 19 6.6 3.6 | -20.3 -4.5 235 38 20 6.9 3.8
18000 -18.0 -0.4 240 35 18 7.6 4.2 | -19.3 -2.7 235 37 19 7.4 4.1
17500 -16.8 1.8 235 33 17 7.9 4.3 | -18.2 -0.8 230 34 18 7.7 4.2
17000 -15.1 4.8 235 31 16 7.4 4.1 | -17.0 1.4 225 32 16 7.8 4.3
16500 -14.0 6.8 230 29 15 7.4 4.0 | -15.2 4.6 220 29 15 8.4 4.6
16000 -12.9 8.8 230 28 14 7.1 3.9 | -13.9 7.0 210 28 15 8.4 4.6
15500 -11.9 10.6 225 26 13 6.8 3.7 | -12.7 9.1 205 28 14 8.5 4.7
15000 -10.9 12.4 225 23 12 6.8 3.8 | -11.4 11.5 200 27 14 8.6 4.7
14500 -9.9 14.2 225 21 11 7.3 4.0 | -10.2 13.6 195 25 13 8.6 4.7
14000 -8.8 16.2 225 18 9 7.5 4.1 | -9.0 15.8 190 23 12 8.6 4.7
13500 -7.8 18.0 220 14 7 6.9 3.8 | -7.7 18.1 185 22 11 9.3 5.1
13000 -6.8 19.8 205 10 5 7.0 3.9 | -6.3 20.7 185 21 11 9.3 5.1
12500 -5.8 21.6 185 8 4 5.9 3.2 | -4.9 23.2 180 19 10 9.3 5.1
12000 -5.0 23.0 165 6 3 5.7 3.1 | -3.5 25.7 175 17 9 9.2 5.1
11500 -4.0 24.8 145 5 3 8.7 4.8 | -2.2 28.0 170 15 8 9.0 4.9
11000 -2.6 27.3 145 5 3 9.1 5.0 | -0.8 30.6 165 12 6 8.9 4.9
10500 -1.3 29.7 145 5 3 9.5 5.2 | 0.5 32.9 155 10 5 9.0 4.9
10250 -0.5 31.1 140 5 2 9.5 5.2 | 1.1 34.0 150 9 5 8.2 4.5
10000 0.1 32.2 140 5 2 8.8 4.8 | 1.7 35.1 145 8 4 7.0 3.9
9750 0.8 33.4 140 5 2 9.5 5.2 | 2.2 36.0 140 7 4 7.3 4.0
9500 1.6 34.9 140 4 2 10.4 5.7 | 2.8 37.0 130 6 3 9.0 5.0
9250 2.4 36.3 135 4 2 11.4 6.3 | 3.5 38.3 125 5 3 10.4 5.7
9000 3.1 37.6 135 4 2 7.6 4.2 | 4.2 39.6 120 5 2 7.4 4.0
8750 3.6 38.5 135 4 2 7.9 4.3 | 4.7 40.5 110 4 2 6.8 3.8
8500 4.4 39.9 135 4 2 11.6 6.4 | 5.3 41.5 100 3 2 10.0 5.5
8250 5.2 41.4 135 4 2 11.9 6.5 | 6.1 43.0 090 3 2 11.7 6.4
8000 6.1 43.0 135 4 2 7.9 4.4 | 6.9 44.4 080 3 1 7.9 4.3
7750 6.5 43.7 135 3 2 7.1 3.9 | 7.4 45.3 060 2 1 6.6 3.6
7500 7.3 45.1 135 3 2 10.8 5.9 | 8.0 46.4 045 2 1 9.9 5.4
7250 8.0 46.4 135 3 2 9.7 5.3 | 8.8 47.8 030 2 1 9.9 5.4
7000 8.8 47.8 130 3 2 10.6 5.8 | 9.5 49.1 015 3 1 9.4 5.2
6750 9.6 49.3 130 3 1 10.6 5.8 | 10.2 50.4 005 3 1 9.2 5.0
6500 10.3 50.5 130 3 1 9.9 5.4 | 10.9 51.6 360 3 2 9.6 5.3
6250 11.1 52.0 130 3 1 10.3 5.6 | 11.6 52.9 355 3 2 9.3 5.1
6000 11.8 53.2 130 2 1 9.7 5.3 | 12.3 54.1 350 3 2 10.1 5.6
5750 12.7 54.9 130 2 1 15.1 8.3 | 13.1 55.6 350 3 2 11.6 6.4
5500 14.2 57.6 130 2 1 25.7 14.1 | 14.0 57.2 345 3 2 11.6 6.4
________________________________________________________________________________
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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