761
UXUS97 KGJT 141307
SRGGJT
SOARING FORECAST
NATIONAL WEATHER SERVICE GRAND JUNCTION, COLORADO
607 AM MST WEDNESDAY, JANUARY 14, 2026
THIS FORECAST IS FOR WEDNESDAY, JANUARY 14, 2026:
IF THE TRIGGER TEMPERATURE OF 58.2 F/14.5 C IS REACHED...THEN
THERMAL SOARING INDEX....................... FAIR
MAXIMUM RATE OF LIFT........................ 226 FT/MIN (1.1 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 7979 FT MSL (2372 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 50.0 F/10.5 C
TIME OF TRIGGER TEMPERATURE.................... NONE
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................. 6796 FT MSL (1189 FT AGL)
THERMAL SOARING OUTLOOK FOR THURSDAY 01/15..... FAIR
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 07:31:59 / 17:14:36 MST
TOTAL POSSIBLE SUNSHINE........... 9 HR 42 MIN 37 SEC (582 MIN 37 SEC)
ALTITUDE OF SUN AT 12:23:17 MST... 29.44 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 01/14/2026 AT 0500 MST
FREEZING LEVEL.................. 5636 FT MSL (29 FT AGL)
ADDITIONAL FREEZING LEVEL....... 11950 FT MSL (6343 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 19903 FT MSL (14296 FT AGL)
LIFTED CONDENSATION LEVEL....... 12878 FT MSL (7271 FT AGL)
LIFTED INDEX.................... +12.5
K INDEX......................... -23.8
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 -65.7 -86.3 325 30 16 3.8 2.1 M M M M M
45000 -59.7 -75.5 320 36 19 4.1 2.2 M M M M M
40000 -53.6 -64.5 300 52 27 4.3 2.3 M M M M M
38000 -52.1 -61.8 305 55 28 2.2 1.2 M M M M M
36000 -50.8 -59.4 315 57 29 2.2 1.2 M M M M M
34000 -48.2 -54.8 315 60 31 7.1 3.9 M M M M M
32000 -43.4 -46.1 320 62 32 7.1 3.9 M M M M M
30000 -39.2 -38.6 320 61 31 7.0 3.8 35.8 96.4 19.5 M M
29000 -37.1 -34.8 320 59 30 7.0 3.8 34.7 94.4 18.9 M M
28000 -35.0 -31.0 320 57 29 7.0 3.8 33.7 92.7 18.4 M M
27000 -32.7 -26.9 320 55 29 8.4 4.6 33.0 91.4 18.0 M M
26000 -30.2 -22.4 320 54 28 8.5 4.6 32.4 90.4 17.8 M M
25000 -27.6 -17.7 320 53 27 8.4 4.6 32.0 89.6 17.7 M M
24000 -25.1 -13.2 320 51 26 8.1 4.4 31.5 88.7 17.5 M M
23000 -22.7 -8.9 325 48 25 8.1 4.4 30.8 87.5 17.1 M M
22000 -20.3 -4.5 325 46 23 8.1 4.4 30.3 86.5 16.9 M M
21000 -17.9 -0.2 325 44 23 8.1 4.5 29.7 85.4 16.6 M M
20000 -15.4 4.3 325 43 22 8.1 4.5 29.1 84.3 16.3 M M
19500 -14.2 6.4 325 42 22 8.1 4.4 28.8 83.9 16.1 M M
19000 -13.0 8.6 325 42 22 7.9 4.3 28.6 83.4 16.0 M M
18500 -11.5 11.3 330 40 20 6.6 3.6 27.8 82.1 15.5 M M
18000 -10.5 13.1 330 38 20 6.5 3.6 27.3 81.1 15.1 M M
17500 -9.5 14.9 330 36 19 6.1 3.4 26.7 80.0 14.7 M M
17000 -8.6 16.5 330 34 18 6.2 3.4 26.1 78.9 14.2 M M
16500 -7.8 18.0 330 32 17 4.9 2.7 25.4 77.7 13.7 M M
16000 -7.1 19.2 330 30 16 4.8 2.7 24.5 76.2 13.0 M M
15500 -6.3 20.7 330 29 15 5.2 2.8 23.7 74.7 12.3 M M
15000 -5.5 22.1 330 27 14 5.5 3.0 23.0 73.4 11.7 M M
14500 -4.7 23.5 330 25 13 5.8 3.2 22.3 72.2 11.1 M M
14000 -3.8 25.2 330 24 12 6.7 3.7 21.8 71.2 10.7 M M
13500 -2.8 27.0 325 23 12 6.6 3.6 21.3 70.3 10.3 M M
13000 -1.8 28.8 325 21 11 6.2 3.4 20.7 69.3 9.8 M M
12500 -0.9 30.4 325 20 10 6.3 3.5 20.2 68.3 9.3 M M
12000 -0.1 31.8 320 19 10 4.9 2.7 19.5 67.1 8.8 M M
11500 0.7 33.3 315 17 9 5.1 2.8 18.7 65.7 8.1 M M
11000 1.3 34.3 310 16 8 3.5 1.9 17.9 64.2 7.3 M M
10500 1.8 35.2 305 14 7 2.6 1.4 16.9 62.4 6.4 M M
10250 1.9 35.4 305 13 7 2.0 1.1 16.3 61.3 5.8 M M
10000 2.1 35.8 300 12 6 3.0 1.6 15.7 60.3 5.3 M M
9750 2.3 36.1 295 11 6 3.0 1.6 15.2 59.4 4.7 M M
9500 2.5 36.5 290 10 5 2.2 1.2 14.7 58.4 4.2 M M
9250 2.5 36.5 285 8 4 0.5 0.3 14.0 57.2 3.5 M M
9000 2.6 36.7 285 7 4 1.2 0.7 13.3 55.9 2.8 M M
8750 2.7 36.9 275 6 3 2.4 1.3 12.7 54.8 2.2 M M
8500 2.8 37.0 265 5 2 1.4 0.8 12.1 53.8 1.6 M M
8250 2.8 37.0 250 4 2 0.5 0.2 11.4 52.5 0.9 M M
8000 2.9 37.2 230 3 1 1.0 0.6 10.7 51.2 0.2 M M
7750 2.9 37.2 205 3 1 1.5 0.8 10.0 50.1 -0.4 219 1.1
7500 3.0 37.4 185 3 2 2.0 1.1 9.4 49.0 -1.1 209 1.1
7250 3.2 37.8 170 4 2 2.5 1.4 8.9 47.9 -1.6 197 1.0
7000 3.4 38.1 165 4 2 2.0 1.1 8.3 46.9 -2.2 185 0.9
6750 3.4 38.1 155 4 2 0.0 0.0 7.6 45.8 -2.9 175 0.9
6500 3.3 37.9 150 4 2 -1.8 -1.0 6.8 44.3 -3.7 170 0.9
6250 3.2 37.8 140 5 2 -1.2 -0.7 6.0 42.7 -4.6 167 0.8
6000 3.1 37.6 135 5 3 -3.2 -1.8 5.1 41.2 -5.4 163 0.8
5750 2.4 36.3 130 5 2 -18.2 -10.0 3.7 38.6 -6.9 177 0.9
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 * * * * * *
01/14/2026 AT 0800 MST | 01/14/2026 AT 1100 MST
|
CAPE... 0.0 LI... +7.5 | CAPE... 0.0 LI... +7.7
CINH... 0.0 K INDEX... +3.0 | CINH... -0.3 K INDEX... +2.2
|
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 -63.5 -82.3 010 53 27 2.1 1.2 | -64.5 -84.1 010 49 25 1.6 0.9
45000 -60.6 -77.1 015 69 36 0.4 0.2 | -61.9 -79.4 010 62 32 2.0 1.1
40000 -60.0 -76.0 020 70 36 0.3 0.2 | -58.9 -74.0 015 62 32 2.3 1.2
38000 -56.6 -69.9 015 70 36 6.4 3.5 | -55.7 -68.3 010 62 32 5.7 3.1
36000 -52.7 -62.9 015 71 36 6.4 3.5 | -52.3 -62.1 005 62 32 5.7 3.1
34000 -48.4 -55.1 015 70 36 7.9 4.4 | -48.1 -54.6 005 63 33 7.8 4.3
32000 -43.6 -46.5 010 69 36 7.9 4.4 | -43.4 -46.1 005 65 34 7.8 4.3
30000 -38.9 -38.0 010 67 35 7.8 4.3 | -38.5 -37.3 005 66 34 8.5 4.7
29000 -36.6 -33.9 005 66 34 7.8 4.3 | -36.0 -32.8 005 66 34 8.5 4.7
28000 -34.2 -29.6 005 64 33 7.8 4.3 | -33.4 -28.1 005 65 34 8.5 4.7
27000 -31.9 -25.4 005 64 33 7.8 4.3 | -30.4 -22.7 005 64 33 7.6 4.2
26000 -29.5 -21.1 005 64 33 7.8 4.3 | -28.1 -18.6 005 62 32 7.6 4.2
25000 -26.6 -15.9 005 64 33 7.8 4.3 | -25.9 -14.6 360 60 31 7.6 4.2
24000 -24.3 -11.7 005 63 32 7.6 4.2 | -23.6 -10.5 360 59 31 7.5 4.1
23000 -22.0 -7.6 005 60 31 7.6 4.2 | -21.3 -6.3 360 59 31 7.5 4.1
22000 -19.7 -3.5 005 58 30 7.8 4.3 | -19.1 -2.4 360 59 30 7.7 4.2
21000 -17.7 0.1 005 55 29 6.3 3.5 | -17.1 1.2 360 57 29 6.4 3.5
20000 -15.9 3.4 005 52 27 6.4 3.5 | -15.2 4.6 005 55 28 6.4 3.5
19500 -14.9 5.2 005 51 26 6.4 3.5 | -14.2 6.4 005 53 27 6.4 3.5
19000 -14.0 6.8 005 49 25 6.3 3.5 | -13.3 8.1 005 52 27 6.0 3.3
18500 -13.0 8.6 005 48 25 6.3 3.5 | -12.4 9.7 005 50 26 5.8 3.2
18000 -12.1 10.2 005 47 24 6.3 3.5 | -11.5 11.3 005 47 24 5.8 3.2
17500 -11.2 11.8 005 46 24 5.8 3.2 | -10.7 12.7 005 45 23 5.3 2.9
17000 -10.3 13.5 010 45 23 5.9 3.2 | -10.0 14.0 005 43 22 5.4 3.0
16500 -9.5 14.9 010 45 23 5.4 2.9 | -9.2 15.4 005 41 21 5.4 3.0
16000 -8.7 16.3 010 44 23 5.3 2.9 | -8.4 16.9 005 39 20 5.4 3.0
15500 -7.9 17.8 010 43 22 5.3 2.9 | -7.6 18.3 010 38 20 5.4 3.0
15000 -7.1 19.2 010 42 22 5.3 2.9 | -6.8 19.8 010 37 19 5.4 3.0
14500 -6.3 20.7 015 42 21 5.1 2.8 | -6.0 21.2 015 36 19 5.3 2.9
14000 -5.7 21.7 015 40 21 4.4 2.4 | -5.2 22.6 015 36 18 4.7 2.6
13500 -5.0 23.0 015 38 20 4.4 2.4 | -4.6 23.7 015 35 18 4.7 2.6
13000 -4.4 24.1 015 36 18 4.5 2.5 | -3.9 25.0 015 34 17 4.2 2.3
12500 -3.7 25.3 015 33 17 4.5 2.5 | -3.3 26.1 015 32 17 4.3 2.3
12000 -3.1 26.4 015 31 16 4.5 2.4 | -2.6 27.3 015 30 15 5.7 3.1
11500 -2.4 27.7 015 28 15 4.4 2.4 | -1.8 28.8 015 27 14 5.6 3.1
11000 -1.7 28.9 020 26 13 5.8 3.2 | -1.1 30.0 015 24 12 4.3 2.4
10500 -0.9 30.4 020 24 12 5.7 3.1 | -0.4 31.3 020 21 11 4.4 2.4
10250 -0.5 31.1 025 23 12 5.2 2.8 | -0.1 31.8 020 20 10 3.3 1.8
10000 -0.1 31.8 025 22 11 5.0 2.7 | 0.1 32.2 020 19 10 3.5 1.9
9750 0.3 32.5 025 21 11 5.4 3.0 | 0.4 32.7 020 17 9 4.8 2.7
9500 0.7 33.3 025 20 10 5.2 2.8 | 0.8 33.4 025 16 8 4.7 2.6
9250 1.0 33.8 030 19 10 4.7 2.6 | 1.1 34.0 025 15 8 4.2 2.3
9000 1.7 35.1 030 17 9 3.4 1.8 | 1.4 34.5 030 14 7 4.1 2.2
8750 1.9 35.4 030 15 8 2.7 1.5 | 2.0 35.6 030 12 6 4.0 2.2
8500 2.1 35.8 035 14 7 2.9 1.6 | 2.3 36.1 035 11 6 4.1 2.2
8250 2.3 36.1 035 13 7 3.3 1.8 | 2.6 36.7 035 10 5 4.3 2.3
8000 2.6 36.7 035 12 6 1.5 0.8 | 2.9 37.2 040 9 5 3.1 1.7
7750 2.6 36.7 035 10 5 1.2 0.7 | 3.1 37.6 040 8 4 2.3 1.3
7500 2.8 37.0 040 9 5 2.9 1.6 | 3.3 37.9 040 7 4 3.0 1.6
7250 3.0 37.4 040 8 4 2.2 1.2 | 3.5 38.3 045 6 3 2.7 1.5
7000 3.2 37.8 045 7 4 3.2 1.7 | 3.7 38.7 045 5 3 2.9 1.6
6750 3.4 38.1 045 8 4 2.8 1.6 | 4.0 39.2 050 5 2 3.7 2.0
6500 3.6 38.5 045 6 3 1.8 1.0 | 4.3 39.7 055 4 2 4.3 2.3
6250 3.7 38.7 050 5 3 2.2 1.2 | 4.6 40.3 060 3 1 3.4 1.8
6000 3.6 38.5 050 4 2 -10.6 -5.8 | 4.9 40.8 065 2 1 7.9 4.3
5750 1.9 35.4 055 3 1 -32.3 -17.7 | 5.8 42.4 070 2 1 17.6 9.7
5500 0.2 32.4 080 1 1 2.2 1.2 | 6.8 44.2 080 1 1 0.8 0.5
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
01/14/2026 AT 1400 MST | 01/14/2026 AT 1700 MST
|
CAPE... 0.0 LI... +8.0 | CAPE... 0.0 LI... +7.5
CINH... 0.0 K INDEX... +2.2 | CINH... -0.1 K INDEX... +0.7
|
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 -64.8 -84.6 015 44 23 1.7 0.9 | -65.2 -85.4 010 37 19 1.7 0.9
45000 -61.9 -79.4 015 55 28 2.9 1.6 | -62.2 -80.0 010 46 24 3.0 1.6
40000 -57.6 -71.7 010 56 29 3.1 1.7 | -57.7 -71.9 360 55 28 2.9 1.6
38000 -54.7 -66.5 005 56 29 5.0 2.8 | -54.5 -66.1 355 57 29 5.7 3.1
36000 -51.7 -61.1 360 58 30 5.0 2.8 | -51.1 -60.0 350 58 30 5.7 3.1
34000 -47.7 -53.9 355 59 30 7.8 4.3 | -46.6 -51.9 345 59 30 7.4 4.1
32000 -43.1 -45.6 360 60 31 7.8 4.3 | -42.1 -43.8 350 58 30 7.4 4.1
30000 -38.3 -36.9 360 62 32 8.1 4.4 | -37.7 -35.9 350 59 31 7.4 4.1
29000 -35.9 -32.6 360 63 33 8.1 4.4 | -35.5 -31.9 350 60 31 7.4 4.1
28000 -33.5 -28.3 360 65 33 8.1 4.4 | -33.3 -27.9 350 61 32 7.4 4.1
27000 -30.4 -22.7 360 65 33 8.3 4.6 | -30.9 -23.6 355 61 31 8.1 4.5
26000 -27.9 -18.2 360 63 33 8.3 4.6 | -28.5 -19.3 355 60 31 8.1 4.5
25000 -25.4 -13.7 005 62 32 8.4 4.6 | -26.0 -14.8 360 59 30 8.1 4.5
24000 -23.1 -9.6 005 60 31 7.0 3.8 | -23.7 -10.7 360 58 30 7.5 4.1
23000 -21.0 -5.8 360 58 30 6.9 3.8 | -21.4 -6.5 360 56 29 7.5 4.1
22000 -18.9 -2.0 360 55 28 7.0 3.8 | -19.2 -2.6 360 53 27 7.5 4.1
21000 -17.0 1.4 360 53 27 6.5 3.6 | -16.7 1.9 360 51 26 6.0 3.3
20000 -15.0 5.0 360 51 26 6.5 3.6 | -14.9 5.2 360 50 26 6.1 3.3
19500 -14.0 6.8 005 51 26 6.5 3.6 | -14.0 6.8 360 49 25 6.1 3.3
19000 -13.1 8.4 005 50 25 5.6 3.1 | -13.2 8.2 360 48 25 5.6 3.1
18500 -12.3 9.9 005 48 24 5.1 2.8 | -12.3 9.9 005 46 24 5.5 3.0
18000 -11.6 11.1 005 46 24 5.0 2.8 | -11.5 11.3 005 45 23 5.5 3.0
17500 -10.9 12.4 010 44 23 4.8 2.6 | -10.8 12.6 005 42 22 5.0 2.7
17000 -10.2 13.6 010 42 22 4.8 2.6 | -10.0 14.0 010 40 21 5.0 2.8
16500 -9.5 14.9 010 40 21 5.2 2.8 | -9.3 15.3 010 38 19 5.4 3.0
16000 -8.7 16.3 010 38 20 5.3 2.9 | -8.5 16.7 010 36 18 5.4 3.0
15500 -7.9 17.8 010 37 19 5.4 3.0 | -7.7 18.1 010 34 17 5.7 3.1
15000 -7.1 19.2 010 35 18 5.6 3.1 | -6.8 19.8 010 32 16 5.8 3.2
14500 -6.3 20.7 010 34 18 5.6 3.1 | -6.0 21.2 015 30 16 5.8 3.2
14000 -5.5 22.1 010 33 17 5.4 3.0 | -5.1 22.8 015 29 15 5.7 3.1
13500 -4.7 23.5 015 31 16 5.5 3.0 | -4.3 24.3 010 27 14 5.7 3.1
13000 -3.9 25.0 015 30 15 5.4 3.0 | -3.5 25.7 010 26 13 5.6 3.1
12500 -3.1 26.4 015 28 14 5.4 3.0 | -2.7 27.1 010 25 13 5.6 3.1
12000 -2.4 27.7 015 26 13 5.1 2.8 | -1.9 28.6 010 23 12 5.1 2.8
11500 -1.6 29.1 015 24 12 5.1 2.8 | -1.2 29.8 010 22 11 5.2 2.8
11000 -0.8 30.6 015 21 11 5.5 3.0 | -0.5 31.1 010 20 10 4.9 2.7
10500 -0.1 31.8 015 18 10 5.4 3.0 | 0.3 32.5 010 17 9 4.9 2.7
10250 0.3 32.5 015 17 9 3.8 2.1 | 0.6 33.1 010 16 8 4.1 2.3
10000 0.5 32.9 015 16 8 3.4 1.9 | 0.9 33.6 010 15 8 4.7 2.6
9750 0.8 33.4 015 15 8 4.4 2.4 | 1.3 34.3 010 14 7 5.7 3.1
9500 1.1 34.0 015 14 7 4.4 2.4 | 1.7 35.1 010 13 6 5.4 3.0
9250 1.5 34.7 020 12 6 4.7 2.6 | 2.1 35.8 010 12 6 5.3 2.9
9000 2.1 35.8 020 10 5 3.8 2.1 | 2.4 36.3 010 11 5 4.9 2.7
8750 2.4 36.3 025 9 5 4.7 2.6 | 2.7 36.9 010 9 5 3.2 1.8
8500 2.8 37.0 025 8 4 6.1 3.3 | 3.0 37.4 010 8 4 4.5 2.5
8250 3.3 37.9 025 8 4 6.1 3.3 | 3.9 39.0 015 7 3 6.3 3.5
8000 3.7 38.7 025 7 4 4.1 2.2 | 4.3 39.7 015 6 3 4.2 2.3
7750 4.0 39.2 025 6 3 4.2 2.3 | 4.6 40.3 015 5 3 4.5 2.5
7500 4.4 39.9 025 5 3 5.9 3.2 | 5.0 41.0 020 5 2 6.2 3.4
7250 4.8 40.6 025 4 2 5.7 3.1 | 5.5 41.9 025 4 2 6.4 3.5
7000 5.2 41.4 025 4 2 4.9 2.7 | 5.9 42.6 035 4 2 3.7 2.0
6750 5.6 42.1 025 2 1 5.9 3.2 | 6.1 43.0 035 2 1 3.5 1.9
6500 6.1 43.0 030 2 1 7.0 3.8 | 6.5 43.7 050 2 1 4.8 2.6
6250 6.6 43.9 035 1 1 8.4 4.6 | 6.8 44.2 070 2 1 8.0 4.4
6000 7.4 45.3 030 2 1 12.9 7.1 | 7.4 45.3 070 3 1 3.0 1.7
5750 8.4 47.1 030 2 1 14.4 7.9 | 6.9 44.4 085 2 1 -17.1 -9.4
5500 9.5 49.1 030 1 1 13.7 7.5 | 6.3 43.3 115 1 1 20.8 11.4
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.
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