944
UXUS97 KBOU 190146
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
1945 MDT WEDNESDAY, MARCH 18, 2026
THIS FORECAST IS FOR THURSDAY, MARCH 19, 2026:
IF THE TRIGGER TEMPERATURE OF 73.4 F/23.0 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1026 FT/MIN (5.2 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 17039 FT MSL (11613 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 84.0 F/29.3 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................. 12110 FT MSL (6684 FT AGL)
THERMAL SOARING OUTLOOK FOR FRIDAY 03/20....... EXCELLENT
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1800 MDT)......... NO CHANGE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1800 MDT)................ NEITHER
POTENTIAL HEIGHT OF WAVE....................... 40050 FT MSL (34624 FT AGL)
WAVE SOARING OUTLOOK FOR FRIDAY 03/20.......... FAIR
REMARKS...
SUNRISE/SUNSET.................... 07:03:52 / 19:10:23 MDT
TOTAL POSSIBLE SUNSHINE........... 12 HR 6 MIN 31 SEC (726 MIN 31 SEC)
ALTITUDE OF SUN AT 13:07:07 MDT... 49.88 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 03/19/2026 AT 0600 MDT
FREEZING LEVEL.................. 14495 FT MSL (9069 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 23583 FT MSL (18157 FT AGL)
LIFTED CONDENSATION LEVEL....... 21307 FT MSL (15881 FT AGL)
LIFTED INDEX.................... +4.3
K INDEX......................... -15.6
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 -67.0 -88.6 320 41 21 1.8 1.0 82.3 180.1 31.0 M M
45000 -63.6 -82.5 320 53 27 3.3 1.8 63.7 146.7 21.7 M M
40000 -58.5 -73.3 315 70 36 6.6 3.6 49.4 121.0 13.7 M M
38000 -54.1 -65.4 315 72 37 7.3 4.0 46.9 116.4 12.3 M M
36000 -49.7 -57.5 320 73 37 7.3 4.0 45.0 113.0 11.3 M M
34000 -44.3 -47.7 320 74 38 8.4 4.6 43.4 110.1 10.5 M M
32000 -39.2 -38.6 320 75 39 8.4 4.6 42.4 108.3 10.0 M M
30000 -34.2 -29.6 320 74 38 8.4 4.6 41.2 106.2 9.4 M M
29000 -31.7 -25.1 320 73 38 8.4 4.6 40.7 105.3 9.1 M M
28000 -29.2 -20.6 320 72 37 8.2 4.5 40.3 104.6 8.9 M M
27000 -26.9 -16.4 320 70 36 7.5 4.1 39.4 102.9 8.3 M M
26000 -24.7 -12.5 315 67 34 7.5 4.1 38.5 101.4 7.7 M M
25000 -22.5 -8.5 315 64 33 7.6 4.2 37.8 100.0 7.2 M M
24000 -20.4 -4.7 315 61 31 6.5 3.5 36.7 98.1 6.3 M M
23000 -18.5 -1.3 315 57 29 6.5 3.6 35.5 95.8 5.4 M M
22000 -16.1 3.0 315 53 27 6.6 3.6 34.1 93.4 4.3 M M
21000 -14.1 6.6 315 49 25 6.8 3.8 33.0 91.4 3.4 M M
20000 -12.0 10.4 315 45 23 6.9 3.8 32.0 89.6 2.6 M M
19500 -11.0 12.2 315 44 23 6.9 3.8 31.5 88.7 2.2 M M
19000 -10.0 14.0 315 42 21 6.2 3.4 31.0 87.8 1.7 M M
18500 -9.1 15.6 315 39 20 6.3 3.4 30.4 86.7 1.2 M M
18000 -8.1 17.4 320 37 19 6.8 3.7 29.8 85.6 0.7 M M
17500 -7.0 19.4 320 34 18 7.2 3.9 29.3 84.8 0.3 M M
17000 -6.0 21.2 325 32 16 7.2 4.7 28.9 84.1 -0.1 1019 5.2
16500 -4.8 23.4 325 30 16 7.9 4.3 28.6 83.4 -0.4 970 4.9
16000 -3.6 25.5 325 29 15 7.8 4.3 28.2 82.8 -0.7 920 4.7
15500 -2.5 27.5 330 27 14 8.1 4.4 27.9 82.3 -0.9 870 4.4
15000 -1.3 29.7 330 27 14 8.1 4.4 27.7 81.8 -1.2 819 4.2
14500 -0.0 32.0 335 26 13 8.0 4.4 27.4 81.3 -1.4 768 3.9
14000 1.2 34.2 330 26 13 8.0 4.4 27.1 80.8 -1.7 717 3.6
13500 2.3 36.1 330 26 13 7.9 4.4 26.8 80.3 -2.0 667 3.4
13000 3.5 38.3 330 26 13 7.8 4.3 26.5 79.7 -2.3 617 3.1
12500 4.7 40.5 325 26 13 7.7 4.2 26.2 79.1 -2.6 568 2.9
12000 5.7 42.3 320 25 13 6.9 3.8 25.8 78.4 -3.1 522 2.7
11500 6.7 44.1 315 25 13 6.9 3.8 25.3 77.6 -3.5 477 2.4
11000 7.7 45.9 310 25 13 6.6 3.6 24.8 76.7 -4.0 432 2.2
10500 8.7 47.7 310 25 13 6.2 3.4 24.4 75.8 -4.5 389 2.0
10250 9.1 48.4 305 25 13 6.0 3.3 24.1 75.3 -4.8 369 1.9
10000 9.6 49.3 305 24 12 7.2 3.9 23.8 74.9 -5.1 347 1.8
9750 10.1 50.2 300 24 12 7.7 4.2 23.6 74.5 -5.3 323 1.6
9500 10.7 51.3 300 23 12 7.5 4.1 23.5 74.2 -5.5 299 1.5
9250 11.2 52.2 300 23 12 6.7 3.7 23.3 73.9 -5.7 276 1.4
9000 11.7 53.1 295 22 11 7.7 4.2 23.0 73.5 -5.9 254 1.3
8750 12.3 54.1 295 22 11 9.0 4.9 23.0 73.3 -6.1 227 1.2
8500 13.0 55.4 295 21 11 8.4 4.6 22.9 73.2 -6.2 200 1.0
8250 13.6 56.5 290 20 11 7.8 4.3 22.7 72.9 -6.3 175 0.9
8000 14.8 58.6 290 19 10 9.2 5.1 22.5 72.5 -6.6 124 0.6
7750 15.5 59.9 290 18 9 7.9 4.3 22.4 72.4 -6.7 97 0.5
7500 16.0 60.8 290 17 9 6.1 3.4 22.2 72.0 -6.9 74 0.4
7250 16.4 61.5 285 17 9 6.6 3.6 21.9 71.5 -7.2 53 0.3
7000 16.8 62.2 285 16 8 3.7 2.0 21.6 70.9 -7.5 33 0.2
6750 16.9 62.4 280 14 7 -2.8 -1.6 20.9 69.7 -8.2 25 0.1
6500 16.5 61.7 275 12 6 -6.3 -3.4 19.8 67.6 -9.4 30 0.2
6250 16.1 61.0 265 11 6 -3.1 -1.7 18.7 65.6 -10.5 34 0.2
6000 15.6 60.1 250 10 5 -13.1 -7.2 17.5 63.6 -11.7 40 0.2
5750 13.7 56.7 240 9 4 -36.5 -20.0 14.9 58.8 -14.4 90 0.5
5500 11.7 53.1 220 7 3 0.9 0.5 12.1 53.8 -17.2 144 0.7
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
03/19/2026 AT 0900 MDT | 03/19/2026 AT 1200 MDT
|
CAPE... 0.0 LI... +5.4 | CAPE... 0.0 LI... +5.2
CINH... -0.4 K INDEX... -19.3 | CINH... -0.1 K INDEX... -14.9
|
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 -68.2 -90.8 315 36 19 2.4 1.3 | -67.5 -89.5 315 35 18 2.4 1.3
45000 -64.3 -83.7 315 51 26 3.4 1.9 | -63.6 -82.5 315 46 24 3.1 1.7
40000 -59.0 -74.2 315 78 40 7.5 4.1 | -58.7 -73.7 310 73 37 7.6 4.2
38000 -54.3 -65.7 315 74 38 7.8 4.3 | -54.0 -65.2 310 74 38 7.9 4.4
36000 -49.0 -56.2 315 70 36 7.8 4.3 | -48.6 -55.5 310 75 39 7.9 4.3
34000 -44.1 -47.4 315 68 35 8.4 4.6 | -43.8 -46.8 310 72 37 8.1 4.5
32000 -39.0 -38.2 320 65 34 8.4 4.6 | -38.9 -38.0 310 67 34 8.1 4.5
30000 -34.1 -29.4 315 65 33 8.2 4.5 | -34.1 -29.4 310 63 33 8.0 4.4
29000 -31.7 -25.1 315 65 33 8.2 4.5 | -31.7 -25.1 310 61 32 8.0 4.4
28000 -29.2 -20.6 315 65 33 8.1 4.5 | -29.3 -20.7 305 60 31 7.8 4.3
27000 -26.8 -16.2 315 63 32 8.0 4.4 | -27.1 -16.8 305 58 30 7.5 4.1
26000 -24.4 -11.9 315 60 31 8.0 4.4 | -24.8 -12.6 305 56 29 7.5 4.1
25000 -22.0 -7.6 315 58 30 8.2 4.5 | -22.6 -8.7 305 54 28 7.6 4.2
24000 -19.9 -3.8 315 55 28 6.7 3.7 | -20.5 -4.9 310 52 27 6.9 3.8
23000 -17.9 -0.2 315 52 27 6.7 3.7 | -18.4 -1.1 310 48 25 6.9 3.8
22000 -15.4 4.3 315 47 24 6.7 3.7 | -15.9 3.4 310 45 23 7.1 3.9
21000 -13.4 7.9 315 45 23 6.7 3.7 | -13.7 7.3 310 41 21 7.2 3.9
20000 -11.4 11.5 315 42 22 6.8 3.7 | -11.6 11.1 310 37 19 7.2 4.0
19500 -10.4 13.3 315 40 21 6.7 3.7 | -10.5 13.1 315 36 18 7.2 4.0
19000 -9.4 15.1 315 38 20 6.5 3.6 | -9.4 15.1 315 34 17 7.5 4.1
18500 -8.4 16.9 315 36 19 6.5 3.6 | -8.3 17.1 315 31 16 7.5 4.1
18000 -7.4 18.7 320 34 17 7.0 3.8 | -7.2 19.0 315 29 15 7.6 4.2
17500 -6.3 20.7 320 31 16 7.2 3.9 | -6.0 21.2 320 27 14 7.6 4.2
17000 -5.3 22.5 320 29 15 7.2 4.0 | -4.9 23.2 320 24 13 7.6 4.2
16500 -4.2 24.4 320 26 14 7.5 4.1 | -3.7 25.3 320 22 12 7.5 4.1
16000 -3.0 26.6 320 24 12 7.4 4.1 | -2.6 27.3 320 20 11 7.4 4.1
15500 -1.9 28.6 320 22 12 7.6 4.2 | -1.5 29.3 320 19 10 7.7 4.2
15000 -0.8 30.6 325 21 11 7.6 4.2 | -0.3 31.5 320 17 9 7.7 4.2
14500 0.4 32.7 325 19 10 7.6 4.2 | 0.8 33.4 320 16 8 7.7 4.2
14000 1.5 34.7 325 19 10 7.6 4.2 | 2.0 35.6 320 15 8 7.6 4.2
13500 2.7 36.9 330 18 9 7.6 4.1 | 3.1 37.6 315 14 7 7.5 4.1
13000 3.8 38.8 325 17 9 7.4 4.1 | 4.2 39.6 310 14 7 7.2 4.0
12500 4.9 40.8 325 17 9 7.3 4.0 | 5.3 41.5 305 14 7 7.1 3.9
12000 5.9 42.6 320 17 9 7.1 3.9 | 6.2 43.2 300 14 7 6.6 3.6
11500 7.0 44.6 315 17 9 7.1 3.9 | 7.2 45.0 295 15 8 6.7 3.7
11000 8.0 46.4 305 17 9 7.2 4.0 | 8.2 46.8 290 16 8 7.0 3.8
10500 9.1 48.4 300 18 9 6.9 3.8 | 9.2 48.6 285 17 9 7.3 4.0
10250 9.6 49.3 300 18 9 6.6 3.6 | 9.8 49.6 285 17 9 8.3 4.6
10000 10.1 50.2 295 18 9 7.2 3.9 | 10.4 50.7 285 17 9 8.6 4.7
9750 10.6 51.1 295 18 9 7.5 4.1 | 11.1 52.0 280 17 8 8.5 4.7
9500 11.2 52.2 295 18 9 7.1 3.9 | 11.7 53.1 280 16 8 8.3 4.5
9250 11.7 53.1 290 18 9 5.8 3.2 | 12.3 54.1 280 16 8 7.6 4.2
9000 12.1 53.8 290 18 9 7.4 4.0 | 12.9 55.2 280 16 8 8.5 4.6
8750 12.7 54.9 290 18 9 9.3 5.1 | 13.5 56.3 280 15 8 9.5 5.2
8500 13.4 56.1 285 17 9 8.2 4.5 | 14.2 57.6 280 15 8 8.7 4.8
8250 14.0 57.2 285 17 9 7.4 4.1 | 14.8 58.6 280 14 7 7.7 4.2
8000 15.1 59.2 285 16 8 8.9 4.9 | 16.1 61.0 275 13 7 9.8 5.4
7750 15.7 60.3 285 15 8 6.5 3.6 | 16.8 62.2 275 12 6 7.7 4.2
7500 16.1 61.0 280 14 7 3.9 2.1 | 17.2 63.0 270 10 5 5.5 3.0
7250 16.4 61.5 280 12 6 4.9 2.7 | 17.6 63.7 265 9 5 6.2 3.4
7000 16.7 62.1 275 11 6 1.6 0.9 | 18.1 64.6 260 8 4 7.5 4.1
6750 16.5 61.7 265 10 5 -4.0 -2.2 | 18.7 65.7 250 7 3 9.0 4.9
6500 16.1 61.0 255 9 5 -5.5 -3.0 | 19.4 66.9 245 6 3 9.3 5.1
6250 15.7 60.3 245 9 5 -5.3 -2.9 | 20.1 68.2 240 6 3 8.4 4.6
6000 15.3 59.5 235 9 5 -4.9 -2.7 | 20.8 69.4 235 6 3 11.8 6.5
5750 14.9 58.8 230 7 4 -3.4 -1.9 | 22.0 71.6 230 5 3 20.1 11.0
5500 14.6 58.3 215 6 3 -6.0 -3.3 | 23.2 73.8 225 4 2 6.6 3.6
03/19/2026 AT 1500 MDT | 03/19/2026 AT 1800 MDT
|
CAPE... 0.0 LI... +4.6 | CAPE... 0.0 LI... +4.0
CINH... 0.0 K INDEX... -6.6 | CINH... -0.2 K INDEX... -3.7
|
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 -66.5 -87.7 310 40 21 2.6 1.4 | -65.1 -85.2 315 45 23 2.2 1.2
45000 -62.6 -80.7 305 53 27 2.5 1.4 | -61.7 -79.1 315 54 28 2.4 1.3
40000 -58.6 -73.5 305 76 39 6.8 3.7 | -58.0 -72.4 300 72 37 5.7 3.1
38000 -54.0 -65.2 305 78 40 7.6 4.2 | -53.8 -64.8 300 77 40 6.9 3.8
36000 -48.9 -56.0 305 80 41 7.6 4.2 | -49.2 -56.6 300 83 43 6.9 3.8
34000 -44.3 -47.7 305 74 38 7.7 4.2 | -44.9 -48.8 305 76 39 7.1 3.9
32000 -39.7 -39.5 305 67 35 7.7 4.2 | -40.7 -41.3 305 67 34 7.2 3.9
30000 -34.9 -30.8 305 63 33 8.0 4.4 | -35.9 -32.6 305 63 33 8.4 4.6
29000 -32.5 -26.5 305 62 32 8.0 4.4 | -33.4 -28.1 305 63 32 8.4 4.6
28000 -30.1 -22.2 305 61 31 8.0 4.4 | -30.9 -23.6 305 62 32 8.3 4.6
27000 -27.7 -17.9 305 58 30 8.0 4.4 | -28.4 -19.1 310 59 30 8.1 4.4
26000 -25.3 -13.5 305 56 29 8.0 4.4 | -26.0 -14.8 310 56 29 8.1 4.4
25000 -23.0 -9.4 305 54 28 8.0 4.4 | -23.6 -10.5 310 52 27 8.1 4.4
24000 -20.7 -5.3 305 51 26 7.2 4.0 | -21.3 -6.3 310 49 25 7.4 4.1
23000 -18.6 -1.5 305 47 24 7.2 4.0 | -19.1 -2.4 310 46 24 7.4 4.1
22000 -15.9 3.4 305 43 22 7.3 4.0 | -16.4 2.5 310 42 22 7.5 4.1
21000 -13.7 7.3 305 40 21 7.3 4.0 | -14.1 6.6 315 40 21 7.6 4.2
20000 -11.5 11.3 310 37 19 7.3 4.0 | -11.8 10.8 315 38 20 7.6 4.2
19500 -10.5 13.1 310 35 18 7.3 4.0 | -10.7 12.7 315 37 19 7.6 4.2
19000 -9.4 15.1 310 34 17 7.3 4.0 | -9.5 14.9 315 36 19 7.8 4.3
18500 -8.3 17.1 310 32 17 7.3 4.0 | -8.4 16.9 315 35 18 7.8 4.3
18000 -7.2 19.0 310 31 16 7.4 4.0 | -7.2 19.0 315 34 17 7.8 4.3
17500 -6.1 21.0 310 29 15 7.4 4.1 | -6.1 21.0 315 32 17 7.9 4.3
17000 -5.0 23.0 310 27 14 7.4 4.1 | -4.9 23.2 315 31 16 7.9 4.3
16500 -3.9 25.0 310 25 13 7.4 4.1 | -3.7 25.3 315 30 15 7.7 4.2
16000 -2.8 27.0 310 24 12 7.4 4.1 | -2.6 27.3 315 29 15 7.7 4.2
15500 -1.7 28.9 305 22 11 7.5 4.1 | -1.5 29.3 310 28 14 7.9 4.3
15000 -0.5 31.1 300 21 11 7.5 4.1 | -0.3 31.5 310 27 14 7.9 4.3
14500 0.6 33.1 295 19 10 7.5 4.1 | 0.9 33.6 305 26 13 8.0 4.4
14000 1.7 35.1 295 19 10 7.6 4.1 | 2.1 35.8 305 25 13 8.1 4.4
13500 2.8 37.0 290 18 9 7.8 4.3 | 3.3 37.9 300 25 13 8.2 4.5
13000 4.0 39.2 290 18 9 8.1 4.5 | 4.5 40.1 295 25 13 8.4 4.6
12500 5.2 41.4 285 18 9 8.3 4.5 | 5.7 42.3 295 25 13 8.5 4.7
12000 6.4 43.5 285 18 9 8.8 4.8 | 7.0 44.6 290 25 13 8.7 4.7
11500 7.8 46.0 290 18 9 8.9 4.9 | 8.3 46.9 290 24 12 8.7 4.8
11000 9.1 48.4 290 18 9 9.3 5.1 | 9.6 49.3 290 24 12 8.8 4.8
10500 10.5 50.9 290 17 9 8.7 4.8 | 10.9 51.6 290 23 12 8.1 4.4
10250 11.1 52.0 290 17 9 9.1 5.0 | 11.5 52.7 290 23 12 8.6 4.7
10000 11.9 53.4 290 17 9 10.0 5.5 | 12.2 54.0 290 23 12 9.9 5.5
9750 12.6 54.7 290 17 9 9.9 5.4 | 12.9 55.2 290 23 12 9.7 5.3
9500 13.3 55.9 290 17 9 9.5 5.2 | 13.7 56.7 295 23 12 9.3 5.1
9250 14.0 57.2 290 17 9 8.7 4.7 | 14.3 57.7 295 23 12 8.4 4.6
9000 14.7 58.5 290 17 9 9.5 5.2 | 15.0 59.0 295 23 12 9.3 5.1
8750 15.4 59.7 295 17 9 10.5 5.8 | 15.7 60.3 295 23 12 10.3 5.7
8500 16.2 61.2 295 17 9 9.7 5.3 | 16.5 61.7 295 22 12 9.7 5.3
8250 16.9 62.4 295 17 9 8.5 4.6 | 17.1 62.8 300 22 11 8.6 4.7
8000 18.3 64.9 295 17 9 10.9 6.0 | 18.5 65.3 300 22 11 10.6 5.8
7750 19.1 66.4 295 17 9 10.0 5.5 | 19.3 66.7 300 22 11 10.0 5.5
7500 19.8 67.6 295 17 9 8.9 4.9 | 20.0 68.0 300 21 11 9.2 5.1
7250 20.5 68.9 295 17 9 9.3 5.1 | 20.7 69.3 305 21 11 9.5 5.2
7000 21.2 70.2 295 17 9 10.2 5.6 | 21.5 70.7 305 20 10 10.3 5.7
6750 22.0 71.6 300 17 9 10.5 5.8 | 22.2 72.0 305 20 10 9.9 5.4
6500 22.7 72.9 300 16 8 10.5 5.8 | 22.9 73.2 305 19 10 9.1 5.0
6250 23.5 74.3 300 15 8 9.7 5.3 | 23.6 74.5 305 18 9 9.5 5.2
6000 24.3 75.7 300 15 8 12.0 6.6 | 24.3 75.7 310 17 9 8.4 4.6
5750 25.4 77.7 300 13 7 19.7 10.8 | 24.8 76.6 310 14 7 5.8 3.2
5500 26.8 80.2 300 10 5 13.9 7.6 | 25.2 77.4 310 10 5 8.7 4.8
________________________________________________________________________________
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