333
UXUS97 KBOU 201220
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
0520 MST WEDNESDAY, FEBRUARY 20, 2019
THIS FORECAST IS FOR WEDNESDAY, FEBRUARY 20, 2019:
IF THE TRIGGER TEMPERATURE OF 25.7 F/-3.5 C IS REACHED...THEN
THERMAL SOARING INDEX....................... GOOD
MAXIMUM RATE OF LIFT........................ 784 FT/MIN (4.0 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 14336 FT MSL (9051 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 32.0 F/0.5 C
TIME OF TRIGGER TEMPERATURE.................... 1045 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................. 10945 FT MSL (5659 FT AGL)
THERMAL SOARING OUTLOOK FOR THURSDAY 02/21..... POOR
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1700 MST)......... NO CHANGE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1700 MST)................ WEAK NVA
POTENTIAL HEIGHT OF WAVE....................... 14389 FT MSL (9104 FT AGL)
WAVE SOARING OUTLOOK FOR THURSDAY 02/21........ FAIR
REMARKS... NONE
SUNRISE/SUNSET.................... 06:45:20 / 17:41:04 MST
TOTAL POSSIBLE SUNSHINE........... 10 HR 55 MIN 44 SEC (655 MIN 44 SEC)
ALTITUDE OF SUN AT 12:13:12 MST... 39.32 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 02/20/2019 AT 0500 MST
FREEZING LEVEL.................. ENTIRE AIRMASS BELOW 32 F / 0 C
CONVECTIVE CONDENSATION LEVEL... 12928 FT MSL (7643 FT AGL)
LIFTED CONDENSATION LEVEL....... 13893 FT MSL (8607 FT AGL)
LIFTED INDEX.................... +7.8
K INDEX......................... -14.1
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 -50.2 -58.4 235 49 25 40.5 22.2 120.2 248.3 68.1 M M
45000 -45.5 -49.9 235 49 25 0.1 0.0 37.6 99.6 27.5 M M
40000 -45.4 -49.7 235 55 28 0.1 0.0 35.6 96.1 26.3 M M
38000 -45.4 -49.7 230 46 24 0.1 0.0 34.8 94.7 25.8 M M
36000 -45.3 -49.5 235 41 21 0.1 0.0 34.0 93.3 25.2 M M
34000 -45.2 -49.4 255 38 20 0.1 0.0 33.2 91.8 24.7 M M
32000 -45.2 -49.4 270 34 18 0.1 0.0 32.5 90.4 24.2 M M
30000 -45.1 -49.2 285 39 20 0.1 0.0 31.6 88.9 23.6 M M
29000 -45.1 -49.2 285 41 21 0.1 0.0 31.2 88.2 23.4 M M
28000 -45.1 -49.2 285 42 22 -0.0 -0.0 28.0 82.4 21.2 M M
27000 -45.1 -49.2 295 48 25 0.0 0.0 24.1 75.4 18.5 M M
26000 -45.1 -49.2 305 54 28 0.0 0.0 20.4 68.7 15.8 M M
25000 -45.1 -49.2 295 55 28 -0.0 -0.0 16.6 61.9 13.1 M M
24000 -45.0 -49.0 295 50 26 2.9 1.6 13.1 55.6 10.5 M M
23000 -43.9 -47.0 295 45 23 3.3 1.8 10.8 51.4 8.7 M M
22000 -43.0 -45.4 285 38 19 6.1 3.3 8.3 47.0 6.8 M M
21000 -41.3 -42.3 270 30 16 5.4 2.9 6.8 44.3 5.6 M M
20000 -39.7 -39.5 275 25 13 5.4 2.9 5.2 41.4 4.4 M M
19500 -38.9 -38.0 280 24 12 5.4 3.0 4.4 40.0 3.7 M M
19000 -38.1 -36.6 285 23 12 5.5 3.0 3.6 38.5 3.1 M M
18500 -37.3 -35.1 295 23 12 6.8 3.7 2.9 37.2 2.5 M M
18000 -36.1 -33.0 300 23 12 8.3 4.6 2.6 36.7 2.2 M M
17500 -34.8 -30.6 305 23 12 8.4 4.6 2.4 36.3 2.1 M M
17000 -33.5 -28.3 310 23 12 9.4 5.2 2.3 36.1 2.0 M M
16500 -32.1 -25.8 310 22 11 9.3 5.1 2.2 36.0 1.9 M M
16000 -30.7 -23.3 310 20 10 9.2 5.1 2.1 35.9 1.9 M M
15500 -29.3 -20.7 305 22 11 7.8 4.3 2.1 35.7 1.8 M M
15000 -28.1 -18.6 300 27 14 4.9 2.7 0.9 33.6 0.8 M M
14500 -27.4 -17.3 295 30 16 4.9 2.7 0.1 32.2 0.1 M M
14000 -26.6 -15.9 295 33 17 4.9 2.7 -0.7 30.8 -0.6 751 3.8
13500 -25.9 -14.6 285 33 17 4.9 2.7 -1.5 29.3 -1.4 714 3.6
13000 -25.2 -13.4 280 34 17 4.5 2.5 -2.3 27.9 -2.1 677 3.4
12500 -24.2 -11.6 275 35 18 9.1 5.0 -2.8 27.0 -2.6 634 3.2
12000 -22.8 -9.0 270 36 18 9.2 5.0 -2.9 26.8 -2.7 578 2.9
11500 -21.4 -6.5 270 34 18 9.2 5.0 -3.0 26.6 -2.9 522 2.6
11000 -20.1 -4.2 270 32 17 9.2 5.0 -3.1 26.4 -3.0 466 2.4
10500 -18.7 -1.7 265 31 16 9.2 5.0 -3.2 26.2 -3.1 410 2.1
10250 -18.0 -0.4 265 30 15 9.2 5.1 -3.3 26.1 -3.2 382 1.9
10000 -17.3 0.9 265 29 15 9.2 5.0 -3.3 26.1 -3.2 354 1.8
9750 -16.6 2.1 265 28 14 9.3 5.1 -3.3 26.0 -3.2 326 1.7
9500 -15.9 3.4 265 27 14 8.8 4.8 -3.3 26.0 -3.3 298 1.5
9250 -15.3 4.5 265 25 13 7.8 4.3 -3.4 25.8 -3.4 272 1.4
9000 -14.8 5.4 265 22 11 7.7 4.2 -3.6 25.5 -3.5 247 1.3
8750 -14.2 6.4 270 20 11 7.7 4.2 -3.8 25.2 -3.7 223 1.1
8500 -13.6 7.5 275 19 10 7.7 4.2 -3.9 24.9 -3.9 198 1.0
8250 -13.0 8.6 280 18 9 7.6 4.2 -4.1 24.6 -4.0 173 0.9
8000 -12.5 9.5 285 17 9 7.6 4.1 -4.2 24.4 -4.2 149 0.8
7750 -11.9 10.6 285 16 8 7.6 4.2 -4.4 24.0 -4.4 125 0.6
7500 -11.3 11.7 280 14 7 7.6 4.2 -4.6 23.7 -4.6 101 0.5
7250 -10.8 12.6 280 13 7 7.6 4.2 -4.8 23.4 -4.8 77 0.4
7000 -10.2 13.6 275 12 6 7.7 4.2 -4.9 23.2 -5.0 52 0.3
6750 -9.7 14.5 270 11 6 7.3 4.0 -5.1 22.8 -5.2 28 0.1
6500 -9.1 15.6 260 10 5 8.7 4.8 -5.3 22.5 -5.4 4 0.0
6250 -8.6 16.5 250 9 4 3.7 2.0 -5.4 22.2 -5.5 M M
6000 -8.6 16.5 240 8 4 -0.2 -0.1 -6.1 20.9 -6.3 M M
5750 -9.1 15.6 230 6 3 -20.6 -11.3 -7.3 18.8 -7.5 M M
5500 -11.9 10.6 205 4 2 -50.3 -27.6 -11.0 12.3 -11.2 59 0.3
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
02/20/2019 AT 0800 MST | 02/20/2019 AT 1100 MST
|
CAPE... 0.0 LI... +6.9 | CAPE... 0.0 LI... +7.3
CINH... 0.0 K INDEX... -14.3 | CINH... -0.1 K INDEX... -9.4
|
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 -52.5 -62.5 235 22 11 1.4 0.8 | -54.0 -65.2 230 23 12 2.5 1.4
45000 -50.3 -58.5 235 25 13 1.4 0.8 | -50.2 -58.4 240 23 12 2.5 1.4
40000 -46.9 -52.4 240 23 12 2.6 1.4 | -47.2 -53.0 245 29 15 1.8 1.0
38000 -45.4 -49.7 245 23 12 2.4 1.3 | -46.1 -51.0 245 32 16 1.6 0.9
36000 -47.2 -53.0 255 25 13 -4.5 -2.5 | -48.6 -55.5 245 33 17 -5.6 -3.1
34000 -49.9 -57.8 265 29 15 -4.5 -2.5 | -52.0 -61.6 250 34 18 -5.6 -3.1
32000 -51.5 -60.7 270 32 16 0.3 0.2 | -53.8 -64.8 255 34 18 0.7 0.4
30000 -51.4 -60.5 280 32 17 0.3 0.1 | -53.4 -64.1 255 33 17 0.7 0.4
29000 -51.3 -60.3 280 33 17 0.8 0.5 | -53.2 -63.8 255 32 17 3.2 1.8
28000 -49.9 -57.8 285 33 17 5.5 3.0 | -51.2 -60.2 255 31 16 7.0 3.8
27000 -48.2 -54.8 290 33 17 5.5 3.0 | -49.1 -56.4 260 30 15 7.0 3.8
26000 -46.6 -51.9 290 33 17 5.6 3.0 | -47.0 -52.6 260 29 15 6.9 3.8
25000 -44.7 -48.5 295 33 17 7.0 3.9 | -44.8 -48.6 260 27 14 7.5 4.1
24000 -42.6 -44.7 295 32 17 7.1 3.9 | -42.6 -44.7 265 26 14 7.5 4.1
23000 -40.5 -40.9 295 31 16 7.0 3.9 | -40.4 -40.7 265 25 13 7.5 4.1
22000 -38.5 -37.3 300 30 15 6.0 3.3 | -38.2 -36.8 270 24 12 7.1 3.9
21000 -36.7 -34.1 300 28 14 5.9 3.3 | -36.0 -32.8 270 22 11 7.1 3.9
20000 -34.5 -30.1 300 26 13 5.2 2.9 | -33.4 -28.1 275 21 11 6.7 3.7
19500 -33.8 -28.8 300 24 13 4.7 2.6 | -32.4 -26.3 275 20 10 6.6 3.6
19000 -33.1 -27.6 300 23 12 4.6 2.5 | -31.4 -24.5 275 19 10 6.6 3.6
18500 -32.4 -26.3 300 22 11 4.6 2.5 | -30.4 -22.7 280 19 10 6.6 3.6
18000 -31.7 -25.1 300 20 10 4.6 2.5 | -29.4 -20.9 280 18 9 6.6 3.6
17500 -31.0 -23.8 305 19 10 4.9 2.7 | -28.5 -19.3 285 18 9 6.1 3.3
17000 -30.3 -22.5 305 18 9 5.1 2.8 | -27.6 -17.7 285 18 9 6.0 3.3
16500 -29.5 -21.1 305 17 9 5.3 2.9 | -26.7 -16.1 285 17 9 6.0 3.3
16000 -28.6 -19.5 305 17 9 6.1 3.4 | -25.8 -14.4 290 17 9 6.0 3.3
15500 -27.7 -17.9 305 16 8 6.1 3.3 | -24.9 -12.8 290 17 9 5.9 3.2
15000 -26.8 -16.2 310 16 8 6.7 3.7 | -24.0 -11.2 295 17 9 5.6 3.1
14500 -25.8 -14.4 310 17 9 6.6 3.6 | -23.2 -9.8 295 17 9 5.7 3.1
14000 -24.8 -12.6 310 17 9 6.3 3.5 | -22.4 -8.3 295 17 9 5.3 2.9
13500 -23.9 -11.0 305 18 9 6.3 3.5 | -21.6 -6.9 300 17 9 5.4 3.0
13000 -23.0 -9.4 305 19 10 5.8 3.2 | -20.8 -5.4 300 17 9 4.7 2.6
12500 -22.1 -7.8 305 20 10 5.8 3.2 | -20.1 -4.2 300 17 9 4.7 2.6
12000 -21.2 -6.2 300 20 10 5.6 3.1 | -19.3 -2.7 300 16 8 5.6 3.1
11500 -20.4 -4.7 300 21 11 5.6 3.1 | -18.5 -1.3 300 16 8 5.6 3.1
11000 -19.6 -3.3 295 21 11 5.5 3.0 | -17.7 0.1 300 16 8 5.2 2.8
10500 -18.8 -1.8 295 21 11 5.6 3.0 | -16.9 1.6 295 16 8 5.2 2.9
10250 -18.4 -1.1 290 21 11 4.8 2.7 | -16.6 2.1 295 15 8 4.6 2.5
10000 -18.0 -0.4 290 21 11 4.1 2.3 | -16.2 2.8 295 15 8 4.6 2.5
9750 -17.7 0.1 290 21 11 6.3 3.5 | -15.8 3.6 295 15 8 6.7 3.7
9500 -17.1 1.2 290 20 10 7.7 4.2 | -15.3 4.5 290 14 7 7.5 4.1
9250 -16.6 2.1 285 19 10 6.9 3.8 | -14.7 5.5 290 13 7 7.0 3.8
9000 -16.1 3.0 285 18 9 6.8 3.7 | -14.2 6.4 290 12 6 6.9 3.8
8750 -15.6 3.9 285 17 9 7.2 4.0 | -13.7 7.3 290 12 6 7.6 4.2
8500 -15.0 5.0 285 16 8 8.2 4.5 | -13.1 8.4 290 10 5 8.5 4.6
8250 -14.4 6.1 285 14 7 8.4 4.6 | -12.5 9.5 290 10 5 8.4 4.6
8000 -13.7 7.3 285 13 7 8.5 4.7 | -11.8 10.8 290 9 5 8.5 4.6
7750 -13.1 8.4 285 12 6 7.9 4.3 | -11.2 11.8 290 8 4 8.3 4.6
7500 -12.5 9.5 280 10 5 8.0 4.4 | -10.6 12.9 290 7 4 8.1 4.5
7250 -11.9 10.6 280 9 5 8.6 4.7 | -10.0 14.0 285 6 3 8.3 4.6
7000 -11.2 11.8 280 8 4 8.6 4.7 | -9.4 15.1 285 5 3 7.8 4.3
6750 -10.6 12.9 275 6 3 8.0 4.4 | -8.8 16.2 285 5 2 8.5 4.7
6500 -10.1 13.8 270 5 3 6.8 3.7 | -8.1 17.4 280 4 2 9.9 5.5
6250 -9.5 14.9 265 5 2 7.4 4.0 | -7.3 18.9 280 4 2 10.2 5.6
6000 -9.0 15.8 250 4 2 5.2 2.8 | -6.6 20.1 275 3 2 9.3 5.1
5750 -8.9 16.0 230 3 2 -1.4 -0.8 | -5.8 21.6 275 3 2 12.3 6.7
5500 -9.2 15.4 210 3 1 -5.9 -3.2 | -4.6 23.7 275 3 2 19.8 10.9
02/20/2019 AT 1400 MST | 02/20/2019 AT 1700 MST
|
CAPE... 0.0 LI... +6.4 | CAPE... 0.0 LI... +4.8
CINH... -0.0 K INDEX... -0.4 | CINH... 0.0 K INDEX... +3.6
|
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 -54.2 -65.6 230 24 13 2.9 1.6 | -53.9 -65.0 235 26 13 2.5 1.4
45000 -49.8 -57.6 235 28 15 2.9 1.6 | -50.1 -58.2 235 33 17 2.5 1.4
40000 -49.0 -56.2 240 34 18 -0.2 -0.1 | -50.5 -58.9 235 37 19 -1.2 -0.6
38000 -49.1 -56.4 240 37 19 -0.3 -0.2 | -51.2 -60.2 235 38 20 -1.2 -0.6
36000 -51.1 -60.0 240 38 20 -3.7 -2.1 | -52.4 -62.3 235 39 20 -2.2 -1.2
34000 -53.3 -63.9 240 39 20 -3.7 -2.1 | -53.9 -65.0 240 41 21 -2.2 -1.2
32000 -54.0 -65.2 245 38 20 1.9 1.0 | -54.1 -65.4 240 42 22 1.6 0.9
30000 -52.9 -63.2 245 36 19 1.9 1.0 | -53.1 -63.6 240 44 22 1.6 0.9
29000 -52.3 -62.1 245 35 18 4.3 2.3 | -52.5 -62.5 245 44 23 5.3 2.9
28000 -50.5 -58.9 250 35 18 6.0 3.3 | -50.6 -59.1 245 43 22 6.6 3.6
27000 -48.7 -55.7 250 34 17 6.0 3.3 | -48.6 -55.5 245 43 22 6.6 3.6
26000 -46.9 -52.4 255 33 17 5.9 3.2 | -46.6 -51.9 245 42 22 6.5 3.5
25000 -44.7 -48.5 255 32 16 7.6 4.2 | -44.5 -48.1 250 40 20 7.4 4.1
24000 -42.5 -44.5 255 30 16 7.6 4.2 | -42.2 -44.0 250 37 19 7.4 4.1
23000 -40.2 -40.4 260 29 15 7.6 4.2 | -40.0 -40.0 250 35 18 7.5 4.1
22000 -37.9 -36.2 260 27 14 7.5 4.1 | -37.8 -36.0 255 32 16 7.2 4.0
21000 -35.7 -32.3 260 26 13 7.5 4.1 | -35.6 -32.1 255 28 15 7.2 4.0
20000 -33.4 -28.1 260 24 12 7.3 4.0 | -33.5 -28.3 255 25 13 7.1 3.9
19500 -31.9 -25.4 260 23 12 6.9 3.8 | -32.4 -26.3 255 24 13 7.0 3.8
19000 -30.8 -23.4 260 22 11 6.9 3.8 | -31.4 -24.5 255 24 12 7.0 3.8
18500 -29.8 -21.6 260 21 11 6.9 3.8 | -29.8 -21.6 255 23 12 7.0 3.8
18000 -28.8 -19.8 260 20 10 7.0 3.8 | -28.8 -19.8 255 22 11 7.0 3.9
17500 -27.8 -18.0 260 19 10 6.2 3.4 | -27.8 -18.0 255 21 11 5.8 3.2
17000 -26.9 -16.4 260 19 10 6.2 3.4 | -27.0 -16.6 255 20 10 5.9 3.3
16500 -25.9 -14.6 265 18 9 5.9 3.2 | -26.1 -15.0 255 19 10 5.9 3.2
16000 -25.1 -13.2 265 18 9 5.7 3.1 | -25.2 -13.4 255 18 9 5.9 3.2
15500 -24.2 -11.6 270 18 9 5.6 3.1 | -24.3 -11.7 260 17 9 6.0 3.3
15000 -23.4 -10.1 270 17 9 5.3 2.9 | -23.4 -10.1 260 17 9 6.3 3.4
14500 -22.6 -8.7 270 17 9 5.3 2.9 | -22.5 -8.5 260 16 8 6.3 3.4
14000 -21.9 -7.4 270 16 8 5.1 2.8 | -21.6 -6.9 260 15 8 6.2 3.4
13500 -21.1 -6.0 270 16 8 5.1 2.8 | -20.6 -5.1 260 14 7 6.3 3.5
13000 -20.3 -4.5 270 15 8 5.6 3.1 | -19.6 -3.3 260 13 7 7.4 4.1
12500 -19.5 -3.1 275 14 7 5.6 3.1 | -18.5 -1.3 260 11 6 7.4 4.1
12000 -18.6 -1.5 275 13 7 6.3 3.5 | -17.4 0.7 255 10 5 8.0 4.4
11500 -17.7 0.1 275 12 6 6.3 3.4 | -16.2 2.8 255 9 5 7.9 4.3
11000 -16.6 2.1 270 11 6 7.7 4.2 | -15.0 5.0 250 8 4 7.9 4.4
10500 -15.5 4.1 270 10 5 7.5 4.1 | -13.8 7.2 250 7 4 7.6 4.2
10250 -14.9 5.2 270 9 5 6.5 3.6 | -13.3 8.1 245 7 3 6.2 3.4
10000 -14.4 6.1 270 9 5 7.0 3.9 | -12.8 9.0 240 6 3 7.2 4.0
9750 -13.8 7.2 270 8 4 9.6 5.3 | -12.2 10.0 240 6 3 10.1 5.5
9500 -13.1 8.4 270 7 4 9.5 5.2 | -11.4 11.5 240 5 3 9.4 5.2
9250 -12.4 9.7 270 6 3 8.3 4.6 | -10.8 12.6 235 4 2 7.9 4.4
9000 -11.8 10.8 270 6 3 8.3 4.6 | -10.2 13.6 225 4 2 8.2 4.5
8750 -11.2 11.8 270 5 3 8.4 4.6 | -9.6 14.7 220 3 2 8.2 4.5
8500 -10.5 13.1 270 4 2 8.8 4.8 | -8.9 16.0 210 3 2 8.8 4.8
8250 -9.9 14.2 270 4 2 8.9 4.9 | -8.3 17.1 200 3 1 9.0 5.0
8000 -9.2 15.4 265 3 2 9.1 5.0 | -7.6 18.3 190 3 1 9.1 5.0
7750 -8.5 16.7 265 3 1 8.1 4.4 | -6.9 19.6 180 3 1 7.5 4.1
7500 -8.0 17.6 260 2 1 8.0 4.4 | -6.4 20.5 170 3 1 7.3 4.0
7250 -7.3 18.9 255 2 1 9.0 4.9 | -5.8 21.6 160 3 1 8.9 4.9
7000 -6.6 20.1 250 2 1 8.9 4.9 | -5.2 22.6 150 3 2 7.9 4.3
6750 -6.0 21.2 255 1 1 9.7 5.3 | -4.6 23.7 145 3 2 8.1 4.4
6500 -5.2 22.6 250 1 1 10.2 5.6 | -3.9 25.0 140 3 2 8.9 4.9
6250 -4.4 24.1 240 1 1 10.1 5.6 | -3.3 26.1 140 3 1 8.7 4.8
6000 -3.7 25.3 230 1 1 9.9 5.4 | -2.6 27.3 135 3 1 9.3 5.1
5750 -2.9 26.8 250 1 1 13.4 7.3 | -1.9 28.6 130 2 1 9.3 5.1
5500 -1.6 29.1 250 1 0 20.1 11.1 | -1.3 29.7 130 2 1 7.7 4.2
________________________________________________________________________________
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