179
UXUS97 KGJT 061307
SRGGJT
SOARING FORECAST
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO
607 AM MST FRIDAY, FEBRUARY 6, 2026
THIS FORECAST IS FOR FRIDAY, FEBRUARY 6, 2026:
IF THE TRIGGER TEMPERATURE OF 55.8 F/13.2 C IS REACHED...THEN
THERMAL SOARING INDEX....................... GOOD
MAXIMUM RATE OF LIFT........................ 577 FT/MIN (2.9 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 12458 FT MSL (6850 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 59.0 F/15.5 C
TIME OF TRIGGER TEMPERATURE.................... 1300 MST
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................. 8426 FT MSL (2819 FT AGL)
THERMAL SOARING OUTLOOK FOR SATURDAY 02/07..... GOOD
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 07:15:34 / 17:40:53 MST
TOTAL POSSIBLE SUNSHINE........... 10 HR 25 MIN 20 SEC (625 MIN 20 SEC)
ALTITUDE OF SUN AT 12:28:13 MST... 35.05 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 02/06/2026 AT 0500 MST
FREEZING LEVEL.................. 10185 FT MSL (4577 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 16225 FT MSL (10617 FT AGL)
LIFTED CONDENSATION LEVEL....... 15123 FT MSL (9515 FT AGL)
LIFTED INDEX.................... +5.4
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 -60.8 -77.4 245 28 14 4.1 2.2 M M M M M
45000 -54.9 -66.8 235 34 17 2.2 1.2 M M M M M
40000 -51.5 -60.7 230 35 18 2.3 1.3 M M M M M
38000 -51.1 -60.0 230 40 21 -0.6 -0.3 M M M M M
36000 -51.5 -60.7 225 50 26 -0.6 -0.3 M M M M M
34000 -50.8 -59.4 220 57 29 4.9 2.7 M M M M M
32000 -47.8 -54.0 215 58 30 5.0 2.7 M M M M M
30000 -44.2 -47.6 215 58 30 8.5 4.6 30.8 87.5 11.9 M M
29000 -41.6 -42.9 215 55 28 8.5 4.7 30.3 86.5 11.6 M M
28000 -39.1 -38.4 215 52 27 8.5 4.7 29.8 85.7 11.4 M M
27000 -36.5 -33.7 215 50 26 8.1 4.5 29.4 85.0 11.2 M M
26000 -34.1 -29.4 215 46 24 8.1 4.4 28.7 83.6 10.8 M M
25000 -31.7 -25.1 215 43 22 8.1 4.4 28.1 82.5 10.4 M M
24000 -29.3 -20.7 220 39 20 7.2 4.0 27.6 81.6 10.1 M M
23000 -27.4 -17.3 220 36 18 6.5 3.6 26.3 79.3 9.1 M M
22000 -25.4 -13.7 220 32 17 6.5 3.6 25.1 77.2 8.3 M M
21000 -23.1 -9.6 220 28 15 6.0 3.3 23.6 74.5 7.1 M M
20000 -21.3 -6.3 230 26 13 6.0 3.3 22.3 72.1 6.0 M M
19500 -20.4 -4.7 235 25 13 6.0 3.3 21.6 70.9 5.5 M M
19000 -19.5 -3.1 240 24 12 6.1 3.4 21.0 69.8 5.0 M M
18500 -18.5 -1.3 245 23 12 7.1 3.9 20.5 68.9 4.6 M M
18000 -17.4 0.7 245 21 11 7.0 3.9 20.0 68.0 4.2 M M
17500 -16.3 2.7 250 20 10 6.9 3.8 19.6 67.2 3.9 M M
17000 -15.3 4.5 250 19 10 6.8 3.8 19.1 66.3 3.4 M M
16500 -14.3 6.3 255 17 9 6.8 3.7 18.6 65.4 3.0 M M
16000 -13.3 8.1 255 17 9 6.8 3.8 18.1 64.5 2.6 M M
15500 -12.3 9.9 255 17 9 6.9 3.8 17.6 63.7 2.1 M M
15000 -11.2 11.8 255 16 8 7.2 3.9 17.1 62.8 1.7 M M
14500 -10.2 13.6 260 16 8 7.1 3.9 16.7 62.1 1.3 M M
14000 -9.1 15.6 260 15 8 7.8 4.3 16.3 61.4 0.9 M M
13500 -8.0 17.6 260 15 7 7.7 4.2 16.0 60.8 0.6 M M
13000 -6.8 19.8 260 14 7 8.1 4.5 15.7 60.3 0.3 M M
12500 -5.6 21.9 260 14 7 8.1 4.5 15.4 59.8 0.0 M M
12000 -4.4 24.1 260 13 7 8.2 4.5 15.2 59.3 -0.2 531 2.7
11500 -3.2 26.2 260 13 7 8.3 4.6 14.9 58.9 -0.5 479 2.4
11000 -2.0 28.4 260 12 6 7.6 4.2 14.7 58.4 -0.7 429 2.2
10500 -0.9 30.4 260 12 6 7.9 4.3 14.3 57.8 -1.1 380 1.9
10250 -0.2 31.6 260 11 6 8.0 4.4 14.2 57.6 -1.2 354 1.8
10000 0.3 32.5 260 11 5 7.2 4.0 14.0 57.2 -1.3 329 1.7
9750 0.9 33.6 260 10 5 7.0 3.8 13.8 56.9 -1.5 306 1.6
9500 1.4 34.5 260 9 5 7.0 3.8 13.6 56.5 -1.7 283 1.4
9250 1.9 35.4 260 9 4 5.8 3.2 13.4 56.0 -2.0 261 1.3
9000 2.3 36.1 255 8 4 5.9 3.2 13.0 55.4 -2.3 241 1.2
8750 2.8 37.0 255 7 3 6.9 3.8 12.8 55.0 -2.6 219 1.1
8500 3.3 37.9 255 6 3 6.0 3.3 12.5 54.6 -2.8 197 1.0
8250 3.7 38.7 250 5 2 4.3 2.4 12.2 53.9 -3.2 178 0.9
8000 4.0 39.2 240 3 2 5.0 2.8 11.8 53.2 -3.6 161 0.8
7750 4.4 39.9 230 3 1 6.4 3.5 11.5 52.6 -3.9 140 0.7
7500 4.9 40.8 215 2 1 5.4 2.9 11.2 52.1 -4.2 120 0.6
7250 5.2 41.4 195 2 1 4.5 2.4 10.8 51.4 -4.6 102 0.5
7000 5.6 42.1 180 3 1 5.4 2.9 10.4 50.8 -5.0 84 0.4
6750 6.0 42.8 175 3 1 4.5 2.5 10.1 50.2 -5.3 64 0.3
6500 6.2 43.2 165 3 1 1.3 0.7 9.6 49.2 -5.8 51 0.3
6250 6.2 43.2 155 3 1 -1.2 -0.7 8.8 47.9 -6.6 43 0.2
6000 6.2 43.2 145 3 2 3.6 2.0 8.1 46.6 -7.3 36 0.2
5750 6.4 43.5 130 3 2 -5.4 -3.0 7.5 45.6 -7.9 23 0.1
5500 M M M M M M M M M M M M
5250 M M M M M M M M M M M M
5000 M M M M M M M M M M M M
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
02/06/2026 AT 0800 MST | 02/06/2026 AT 1100 MST
|
CAPE... 0.0 LI... +8.1 | CAPE... 0.0 LI... +8.2
CINH... 0.0 K INDEX... -3.5 | CINH... -0.1 K INDEX... -9.0
|
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 -62.3 -80.1 215 22 11 2.8 1.5 | -62.3 -80.1 225 23 12 2.1 1.2
45000 -58.5 -73.3 215 25 13 0.1 0.1 | -59.1 -74.4 225 31 16 2.3 1.3
40000 -58.2 -72.8 190 30 15 -0.0 -0.0 | -55.5 -67.9 205 35 18 2.3 1.3
38000 -56.0 -68.8 185 33 17 4.4 2.4 | -54.4 -65.9 195 38 20 1.8 1.0
36000 -53.4 -64.1 180 37 19 4.4 2.4 | -53.3 -63.9 190 42 22 1.8 1.0
34000 -49.9 -57.8 175 38 20 7.7 4.2 | -50.6 -59.1 190 43 22 8.2 4.5
32000 -45.3 -49.5 170 37 19 7.7 4.2 | -45.7 -50.3 190 39 20 8.2 4.5
30000 -40.4 -40.7 170 36 19 8.6 4.7 | -40.6 -41.1 190 37 19 8.8 4.8
29000 -37.8 -36.0 170 35 18 8.6 4.7 | -38.0 -36.4 190 36 19 8.8 4.8
28000 -35.2 -31.4 170 34 18 8.6 4.7 | -35.3 -31.5 190 36 18 8.8 4.8
27000 -32.7 -26.9 170 33 17 8.0 4.4 | -32.8 -27.0 185 35 18 7.2 3.9
26000 -30.3 -22.5 170 31 16 8.0 4.4 | -30.1 -22.2 185 34 18 7.3 4.0
25000 -27.3 -17.1 170 29 15 8.0 4.4 | -27.9 -18.2 185 34 17 7.3 4.0
24000 -25.0 -13.0 170 26 14 7.7 4.2 | -25.7 -14.3 185 32 17 7.5 4.1
23000 -22.7 -8.9 175 24 12 7.7 4.2 | -23.5 -10.3 185 30 16 7.5 4.1
22000 -20.4 -4.7 175 22 11 7.7 4.2 | -21.2 -6.2 180 28 14 7.5 4.1
21000 -18.3 -0.9 180 20 10 6.6 3.6 | -19.1 -2.4 185 26 13 6.9 3.8
20000 -16.3 2.7 180 18 9 6.6 3.6 | -17.0 1.4 185 24 12 6.9 3.8
19500 -15.3 4.5 185 17 9 6.6 3.6 | -16.0 3.2 190 23 12 6.9 3.8
19000 -14.3 6.3 185 16 8 6.5 3.6 | -14.9 5.2 190 21 11 6.8 3.7
18500 -13.4 7.9 185 16 8 6.2 3.4 | -13.9 7.0 195 20 11 6.7 3.7
18000 -12.5 9.5 190 16 8 6.2 3.4 | -12.9 8.8 195 19 10 6.7 3.7
17500 -11.6 11.1 190 16 8 6.2 3.4 | -12.0 10.4 195 18 10 6.3 3.5
17000 -10.6 12.9 190 15 8 6.2 3.4 | -11.0 12.2 195 18 9 6.3 3.5
16500 -9.7 14.5 190 15 8 6.3 3.4 | -10.1 13.8 195 17 9 6.2 3.4
16000 -8.8 16.2 195 15 8 6.3 3.5 | -9.2 15.4 195 16 8 6.0 3.3
15500 -7.8 18.0 195 15 8 6.3 3.5 | -8.3 17.1 195 16 8 6.0 3.3
15000 -6.9 19.6 200 14 7 6.5 3.6 | -7.4 18.7 195 15 8 6.0 3.3
14500 -5.9 21.4 200 14 7 6.6 3.6 | -6.5 20.3 195 15 8 6.0 3.3
14000 -5.0 23.0 200 14 7 5.8 3.2 | -5.6 21.9 200 15 8 5.5 3.0
13500 -4.1 24.6 200 14 7 6.0 3.3 | -4.8 23.4 200 15 8 5.6 3.1
13000 -3.3 26.1 200 13 7 4.9 2.7 | -4.0 24.8 200 15 8 5.4 2.9
12500 -2.5 27.5 200 13 7 4.9 2.7 | -3.2 26.2 200 15 8 5.4 3.0
12000 -1.8 28.8 200 12 6 4.8 2.6 | -2.4 27.7 205 15 8 5.2 2.9
11500 -1.1 30.0 200 12 6 4.8 2.6 | -1.6 29.1 205 15 8 5.2 2.9
11000 -0.4 31.3 200 11 6 4.8 2.6 | -0.9 30.4 205 15 8 5.3 2.9
10500 0.3 32.5 200 11 5 5.0 2.7 | -0.1 31.8 205 14 7 5.7 3.1
10250 0.7 33.3 195 10 5 4.2 2.3 | 0.3 32.5 205 14 7 3.9 2.2
10000 0.9 33.6 195 10 5 4.3 2.4 | 0.5 32.9 210 13 7 4.3 2.4
9750 1.3 34.3 195 10 5 5.3 2.9 | 1.0 33.8 210 13 7 6.5 3.5
9500 1.7 35.1 190 9 5 5.0 2.7 | 1.4 34.5 210 12 6 6.1 3.3
9250 2.1 35.8 190 9 5 5.5 3.0 | 1.9 35.4 210 11 6 6.0 3.3
9000 2.9 37.2 185 9 5 4.5 2.5 | 2.7 36.9 210 10 5 5.4 3.0
8750 3.2 37.8 180 9 4 4.2 2.3 | 3.1 37.6 210 10 5 5.3 2.9
8500 3.5 38.3 180 9 4 4.8 2.7 | 3.4 38.1 205 9 5 5.1 2.8
8250 3.9 39.0 175 9 5 5.2 2.9 | 3.8 38.8 205 9 5 5.0 2.7
8000 4.2 39.6 170 9 5 3.8 2.1 | 4.2 39.6 205 8 4 5.5 3.0
7750 4.4 39.9 170 8 4 3.2 1.7 | 4.6 40.3 200 8 4 4.5 2.5
7500 4.7 40.5 165 8 4 3.7 2.0 | 4.8 40.6 200 7 3 3.7 2.0
7250 5.0 41.0 160 8 4 3.9 2.2 | 5.1 41.2 195 6 3 2.6 1.4
7000 5.2 41.4 155 8 4 2.8 1.6 | 5.4 41.7 195 5 2 7.5 4.1
6750 5.4 41.7 155 6 3 1.6 0.9 | 6.1 43.0 190 4 2 9.0 4.9
6500 5.5 41.9 150 5 3 1.1 0.6 | 6.6 43.9 190 4 2 6.4 3.5
6250 5.6 42.1 140 5 2 3.0 1.7 | 7.1 44.8 190 3 1 4.1 2.3
6000 5.5 41.9 135 5 2 -11.8 -6.5 | 7.3 45.1 185 1 1 7.1 3.9
5750 3.5 38.3 115 4 2 -40.7 -22.4 | 8.4 47.1 185 1 0 22.6 12.4
5500 1.6 34.9 085 4 2 18.6 10.2 | 9.6 49.3 185 1 0 -5.4 -3.0
5250 M M M M M M M | M M M M M M M
5000 M M M M M M M | M M M M M M M
02/06/2026 AT 1400 MST | 02/06/2026 AT 1700 MST
|
CAPE... 0.0 LI... +6.9 | CAPE... 0.0 LI... +6.2
CINH... -0.1 K INDEX... -5.1 | CINH... -0.1 K INDEX... +8.2
|
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 -61.7 -79.1 230 23 12 2.6 1.4 | -61.3 -78.3 235 28 14 3.4 1.9
45000 -57.9 -72.2 230 34 18 2.1 1.1 | -56.4 -69.5 235 39 20 1.7 0.9
40000 -54.6 -66.3 215 43 22 2.1 1.1 | -53.6 -64.5 225 44 23 1.7 0.9
38000 -54.0 -65.2 215 47 24 0.8 0.4 | -53.3 -63.9 220 50 25 0.0 0.0
36000 -53.5 -64.3 210 52 27 0.8 0.4 | -53.3 -63.9 220 56 29 0.0 0.0
34000 -51.2 -60.2 210 53 27 8.5 4.6 | -51.4 -60.5 215 58 30 8.4 4.6
32000 -46.1 -51.0 210 51 26 8.4 4.6 | -46.4 -51.5 215 53 27 8.3 4.6
30000 -41.1 -42.0 210 47 24 8.4 4.6 | -41.4 -42.5 215 47 24 8.2 4.5
29000 -38.6 -37.5 210 44 23 8.4 4.6 | -39.0 -38.2 215 44 23 8.2 4.5
28000 -36.1 -33.0 210 42 21 8.4 4.6 | -36.5 -33.7 210 41 21 8.2 4.5
27000 -33.5 -28.3 205 39 20 8.4 4.6 | -34.1 -29.4 210 39 20 7.4 4.1
26000 -31.0 -23.8 205 36 19 8.4 4.6 | -31.9 -25.4 210 37 19 7.5 4.1
25000 -28.5 -19.3 205 33 17 8.4 4.6 | -29.6 -21.3 215 35 18 7.5 4.1
24000 -25.5 -13.9 200 31 16 6.7 3.7 | -26.8 -16.2 215 32 17 7.8 4.3
23000 -23.5 -10.3 200 30 15 6.8 3.7 | -24.4 -11.9 215 29 15 7.8 4.3
22000 -21.5 -6.7 205 29 15 6.8 3.7 | -22.1 -7.8 215 25 13 7.8 4.3
21000 -19.6 -3.3 205 28 14 6.1 3.3 | -19.9 -3.8 215 24 12 6.7 3.7
20000 -17.8 -0.0 200 26 13 6.1 3.3 | -18.0 -0.4 215 24 12 6.6 3.6
19500 -16.9 1.6 200 25 13 6.1 3.4 | -17.0 1.4 215 24 12 6.6 3.6
19000 -16.0 3.2 200 25 13 6.2 3.4 | -16.0 3.2 215 24 12 6.4 3.5
18500 -15.1 4.8 200 23 12 6.4 3.5 | -15.1 4.8 215 24 12 5.3 2.9
18000 -14.1 6.6 200 22 11 6.3 3.5 | -14.4 6.1 215 23 12 5.3 2.9
17500 -13.2 8.2 200 21 11 6.9 3.8 | -13.6 7.5 215 22 11 5.5 3.0
17000 -12.1 10.2 200 20 10 6.9 3.8 | -12.8 9.0 210 21 11 5.6 3.1
16500 -11.1 12.0 200 19 10 6.7 3.7 | -12.0 10.4 210 20 10 6.0 3.3
16000 -10.1 13.8 205 19 10 6.5 3.6 | -11.1 12.0 210 19 10 6.3 3.5
15500 -9.1 15.6 205 18 9 6.4 3.5 | -10.2 13.6 210 19 10 6.4 3.5
15000 -8.1 17.4 210 18 9 6.1 3.4 | -9.1 15.6 215 18 9 7.1 3.9
14500 -7.2 19.0 210 18 9 6.1 3.4 | -8.1 17.4 215 18 9 7.1 3.9
14000 -6.3 20.7 210 17 9 6.4 3.5 | -7.1 19.2 220 18 9 6.7 3.7
13500 -5.3 22.5 215 17 9 6.4 3.5 | -6.1 21.0 225 18 9 6.7 3.7
13000 -4.4 24.1 215 17 9 6.1 3.3 | -5.0 23.0 225 17 9 7.1 3.9
12500 -3.5 25.7 215 17 9 6.1 3.3 | -3.9 25.0 230 17 9 7.1 3.9
12000 -2.6 27.3 220 17 9 6.0 3.3 | -2.9 26.8 230 16 8 7.0 3.8
11500 -1.7 28.9 215 16 8 6.0 3.3 | -1.8 28.8 225 15 8 7.0 3.8
11000 -0.8 30.6 215 15 8 5.9 3.3 | -0.8 30.6 225 14 7 6.7 3.7
10500 0.0 32.0 215 14 7 6.2 3.4 | 0.2 32.4 220 13 7 6.8 3.7
10250 0.4 32.7 215 14 7 4.8 2.6 | 0.7 33.3 220 12 6 6.0 3.3
10000 0.7 33.3 215 14 7 5.3 2.9 | 1.1 34.0 220 13 6 6.1 3.3
9750 1.2 34.2 215 13 7 7.1 3.9 | 1.6 34.9 215 11 6 7.0 3.8
9500 1.7 35.1 215 12 6 6.8 3.7 | 2.1 35.8 215 10 5 6.7 3.7
9250 2.2 36.0 215 11 6 6.3 3.4 | 2.5 36.5 215 9 5 6.9 3.8
9000 2.6 36.7 215 10 5 5.8 3.2 | 3.1 37.6 210 8 4 6.8 3.7
8750 3.1 37.6 215 9 5 6.5 3.6 | 3.5 38.3 210 7 4 6.4 3.5
8500 3.6 38.5 215 8 4 6.4 3.5 | 4.0 39.2 210 6 3 6.3 3.5
8250 4.0 39.2 215 7 3 4.9 2.7 | 4.9 40.8 210 5 2 5.7 3.1
8000 4.7 40.5 220 4 2 8.4 4.6 | 5.4 41.7 215 4 2 8.2 4.5
7750 5.5 41.9 225 4 2 8.7 4.8 | 6.0 42.8 225 3 2 8.0 4.4
7500 5.9 42.6 230 3 2 6.0 3.3 | 6.5 43.7 240 2 1 5.6 3.1
7250 6.4 43.5 245 3 1 5.0 2.8 | 6.9 44.4 265 2 1 4.8 2.7
7000 6.9 44.4 260 2 1 11.8 6.5 | 7.3 45.1 290 2 1 8.7 4.8
6750 8.0 46.4 245 3 1 12.8 7.0 | 8.1 46.6 290 2 1 10.0 5.5
6500 8.6 47.5 255 2 1 7.9 4.3 | 8.7 47.7 300 3 1 7.5 4.1
6250 9.3 48.7 270 2 1 8.1 4.5 | 9.4 48.9 310 3 2 8.3 4.6
6000 10.0 50.0 285 2 1 12.3 6.7 | 10.0 50.0 315 4 2 7.7 4.2
5750 11.3 52.3 270 2 1 23.1 12.7 | 10.5 50.9 305 3 2 6.1 3.4
5500 12.5 54.5 290 2 1 -2.0 -1.1 | 10.8 51.4 315 3 2 3.9 2.2
5250 M M M M M M M | M M M M M M M
5000 M M M M M M M | M M M M M M M
________________________________________________________________________________
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 AT WALKER FIELD IN GRAND
JUNCTION, COLORADO AT
NORTH LATITUDE: 39 DEG 07 MIN 00.001 SEC
WEST LONGITUDE: 108 DEG 31 MIN 59.998 SEC
ELEVATION: 4839 FEET (1475 METERS)
AND MAY NOT BE REPRESENTATIVE OF OTHER AREAS ALONG THE WESTERN SLOPE OF
COLORADO. 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