467
UXUS97 KBOU 241247
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
546 AM MST TUESDAY NOVEMBER 24, 2009
THIS FORECAST IS FOR TUESDAY NOVEMBER 24, 2009:
IF THE TRIGGER TEMPERATURE OF 41.5 F/5.3 C IS REACHED...THEN
THERMAL SOARING INDEX....................... GOOD
MAXIMUM RATE OF LIFT........................ 417 FT/MIN (2.1 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 11045 FT MSL (5760 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 46.0 F/8.2 C
TIME OF TRIGGER TEMPERATURE.................... 1100 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................. 8952 FT MSL (3666 FT AGL)
THERMAL SOARING OUTLOOK FOR WEDNESDAY 11/25.... FAIR
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1700 MST)......... NO CHANGE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... 12426 FT MSL (7141 FT AGL)
WEAK PVA/NVA (THROUGH 1700 MST)................ WEAK NVA
POTENTIAL HEIGHT OF WAVE....................... 17350 FT MSL (12065 FT AGL)
WAVE SOARING OUTLOOK FOR WEDNESDAY 11/25....... POOR
REMARKS... NONE
SUNRISE/SUNSET.................... 06:54:29 / 16:38:02 MST
TOTAL POSSIBLE SUNSHINE........... 9 HR 43 MIN 34 SEC (583 MIN 34 SEC)
ALTITUDE OF SUN AT 11:46:25 MST... 29.60 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 11/24/2009 AT 0500 MST
FREEZING LEVEL.................. ENTIRE AIRMASS BELOW 32 F / 0 C
CONVECTIVE CONDENSATION LEVEL... 19835 FT MSL (14550 FT AGL)
LIFTED CONDENSATION LEVEL....... 15113 FT MSL (9828 FT AGL)
LIFTED INDEX.................... +10.2
K INDEX......................... -16.9
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 -59.6 -75.3 251 27 14 7.0 3.9 103.7 218.6 54.3 M M
45000 -54.9 -66.8 307 28 15 5.7 3.1 85.2 185.3 47.1 M M
40000 -55.2 -67.4 320 59 30 5.7 3.1 61.5 142.8 35.0 M M
38000 -56.6 -69.9 310 55 28 -4.7 -2.6 50.6 123.0 28.6 M M
36000 -58.5 -73.3 319 52 27 0.1 0.0 39.0 102.2 21.5 M M
34000 -57.0 -70.6 334 60 31 3.9 2.2 32.8 91.0 17.7 M M
32000 -53.4 -64.1 328 68 35 0.2 0.1 29.6 85.4 15.9 M M
30000 -48.9 -56.0 325 69 35 7.3 4.0 26.8 80.2 14.2 M M
29000 -46.7 -52.1 329 64 33 7.5 4.1 25.8 78.5 13.7 M M
28000 -44.4 -47.9 333 59 31 8.8 4.8 25.0 77.1 13.2 M M
27000 -41.8 -43.2 338 55 29 8.7 4.8 24.6 76.2 13.0 M M
26000 -39.2 -38.6 343 52 27 8.7 4.8 24.2 75.6 12.9 M M
25000 -36.6 -33.9 350 49 25 8.7 4.8 24.0 75.1 12.9 M M
24000 -33.9 -29.0 350 53 27 8.7 4.8 23.5 74.3 12.7 M M
23000 -31.4 -24.5 346 54 28 8.6 4.7 23.0 73.4 12.4 M M
22000 -29.0 -20.2 342 55 28 5.4 3.0 22.3 72.2 12.0 M M
21000 -27.1 -16.8 338 56 29 9.7 5.3 21.2 70.2 11.2 M M
20000 -24.2 -11.6 335 57 29 9.4 5.2 21.1 70.0 11.3 M M
19500 -22.8 -9.0 335 58 30 9.4 5.2 21.0 69.9 11.3 M M
19000 -21.4 -6.5 335 58 30 9.4 5.2 21.0 69.8 11.3 M M
18500 -20.1 -4.2 335 59 30 7.2 4.0 20.9 69.6 11.2 M M
18000 -19.0 -2.2 339 60 31 8.0 4.4 20.4 68.7 10.9 M M
17500 -17.8 -0.0 344 61 31 7.8 4.3 20.0 68.1 10.6 M M
17000 -16.7 1.9 349 63 32 8.2 4.5 19.8 67.6 10.4 M M
16500 -15.4 4.3 350 61 31 8.3 4.5 19.5 67.1 10.2 M M
16000 -14.2 6.4 350 58 30 8.2 4.5 19.2 66.6 10.1 M M
15500 -12.5 9.5 347 54 28 2.6 1.4 18.6 65.6 9.7 M M
15000 -12.5 9.5 344 51 26 1.5 0.8 17.0 62.6 8.2 M M
14500 -11.7 10.9 342 49 25 8.7 4.8 16.3 61.4 7.7 M M
14000 -10.9 12.4 339 47 24 1.9 1.0 15.5 60.0 7.0 M M
13500 -10.5 13.1 337 46 24 2.4 1.3 14.3 57.8 5.9 M M
13000 -10.2 13.6 335 43 22 1.2 0.7 13.2 55.7 4.9 M M
12500 -10.4 13.3 335 33 17 -2.0 -1.1 11.4 52.5 3.2 M M
12000 -10.0 14.0 334 23 12 5.9 3.3 10.2 50.4 2.2 M M
11500 -9.2 15.4 324 16 8 2.4 1.3 9.5 49.2 1.5 M M
11000 -9.6 14.7 304 10 5 0.5 0.3 7.5 45.5 -0.4 418 2.1
10500 -8.7 16.3 296 9 5 7.8 4.3 7.0 44.6 -0.9 373 1.9
10250 -8.1 17.4 292 9 5 7.7 4.2 6.8 44.3 -1.1 349 1.8
10000 -7.5 18.5 285 9 4 6.2 3.4 6.6 44.0 -1.2 325 1.7
9750 -7.2 19.0 271 7 4 4.2 2.3 6.3 43.3 -1.6 307 1.6
9500 -6.9 19.6 253 7 4 3.7 2.1 5.8 42.5 -2.1 291 1.5
9250 -6.6 20.1 234 7 4 3.9 2.1 5.4 41.6 -2.5 275 1.4
9000 -6.3 20.7 219 8 4 3.8 2.1 4.9 40.8 -2.9 259 1.3
8750 -6.0 21.2 209 7 4 3.9 2.1 4.4 40.0 -3.4 243 1.2
8500 -5.7 21.7 198 6 3 3.6 2.0 4.0 39.2 -3.9 227 1.2
8250 -5.4 22.3 184 6 3 7.1 3.9 3.6 38.5 -4.3 209 1.1
8000 -4.7 23.5 170 6 3 10.0 5.5 3.6 38.4 -4.3 181 0.9
7750 -4.0 24.8 176 7 3 9.2 5.1 3.5 38.4 -4.3 152 0.8
7500 -3.3 26.1 181 7 4 9.5 5.2 3.5 38.3 -4.4 124 0.6
7250 -2.6 27.3 186 8 4 9.2 5.0 3.5 38.3 -4.4 96 0.5
7000 -1.9 28.6 189 9 5 10.1 5.5 3.5 38.2 -4.5 67 0.3
6750 -1.2 29.8 200 10 5 6.8 3.7 3.4 38.2 -4.5 39 0.2
6500 -0.9 30.4 210 10 5 3.2 1.8 3.0 37.4 -4.9 22 0.1
6250 -0.7 30.7 218 12 6 2.5 1.3 2.5 36.5 -5.4 8 0.0
6000 -0.4 31.3 224 13 7 6.5 3.6 2.0 35.7 -5.9 M M
5750 -0.3 31.5 221 11 6 -13.8 -7.6 1.4 34.6 -6.6 M M
5500 -3.0 26.6 214 9 5 -53.3 -29.2 -2.0 28.4 -10.0 54 0.3
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
11/24/2009 AT 0800 MST | 11/24/2009 AT 1100 MST
|
K INDEX... -22.8 | K INDEX... -16.9
|
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 -57.8 -72.0 305 22 11 1.4 0.7 | -58.6 -73.5 310 24 12 1.0 0.5
45000 -55.7 -68.3 315 30 16 1.7 0.9 | -57.0 -70.6 319 34 17 1.3 0.7
40000 -58.3 -72.9 323 42 22 -1.9 -1.0 | -59.5 -75.1 314 39 20 -1.8 -1.0
38000 -58.9 -74.0 327 46 24 0.5 0.3 | -59.9 -75.8 315 41 21 1.6 0.9
36000 -58.6 -73.5 334 47 24 0.6 0.3 | -59.0 -74.2 323 43 22 1.6 0.9
34000 -58.2 -72.8 340 49 25 3.3 1.8 | -57.9 -72.2 330 47 24 4.7 2.6
32000 -54.1 -65.4 351 52 27 7.0 3.8 | -53.9 -65.0 339 44 23 6.8 3.7
30000 -49.2 -56.6 359 56 29 8.5 4.7 | -49.1 -56.4 347 44 23 8.9 4.9
29000 -46.7 -52.1 359 55 28 8.4 4.6 | -46.4 -51.5 348 45 23 8.8 4.8
28000 -44.2 -47.6 358 53 27 8.4 4.6 | -43.8 -46.8 349 47 24 8.8 4.8
27000 -41.7 -43.1 358 51 26 8.7 4.8 | -41.2 -42.2 349 48 25 9.1 5.0
26000 -38.9 -38.0 355 50 26 9.4 5.1 | -38.4 -37.1 350 46 24 9.4 5.2
25000 -36.1 -33.0 352 50 26 9.4 5.1 | -35.5 -31.9 350 45 23 9.4 5.2
24000 -33.3 -27.9 349 49 25 9.2 5.1 | -32.7 -26.9 350 43 22 9.1 5.0
23000 -30.9 -23.6 349 50 26 7.7 4.2 | -30.3 -22.5 350 42 22 8.0 4.4
22000 -28.6 -19.5 349 50 26 7.7 4.2 | -27.9 -18.2 351 41 21 8.0 4.4
21000 -26.3 -15.3 349 51 26 8.0 4.4 | -25.5 -13.9 352 40 20 8.4 4.6
20000 -23.8 -10.8 347 52 27 8.3 4.5 | -22.9 -9.2 350 40 21 8.5 4.7
19500 -22.6 -8.7 346 52 27 8.3 4.5 | -21.6 -6.9 350 40 21 8.5 4.7
19000 -21.4 -6.5 346 53 27 8.3 4.5 | -20.4 -4.7 349 40 21 8.5 4.7
18500 -20.1 -4.2 345 53 27 8.4 4.6 | -19.1 -2.4 348 41 21 8.4 4.6
18000 -18.8 -1.8 344 51 26 8.7 4.8 | -17.9 -0.2 347 41 21 8.3 4.5
17500 -17.5 0.5 344 49 25 8.7 4.8 | -16.6 2.1 345 41 21 8.3 4.5
17000 -15.6 3.9 345 48 24 8.3 4.5 | -14.9 5.2 344 40 21 7.7 4.2
16500 -14.4 6.1 347 47 24 8.2 4.5 | -13.7 7.3 343 39 20 7.5 4.1
16000 -13.2 8.2 349 46 24 7.4 4.1 | -12.7 9.1 342 38 19 6.4 3.5
15500 -12.1 10.2 351 45 23 7.6 4.2 | -11.7 10.9 342 36 18 6.5 3.6
15000 -11.1 12.0 353 45 23 6.3 3.5 | -10.8 12.6 343 34 17 6.1 3.3
14500 -10.1 13.8 355 44 23 6.4 3.5 | -9.9 14.2 345 32 16 6.2 3.4
14000 -9.2 15.4 356 43 22 5.6 3.1 | -9.0 15.8 346 30 15 5.4 3.0
13500 -8.4 16.9 355 41 21 5.4 3.0 | -8.2 17.2 348 28 14 5.3 2.9
13000 -7.6 18.3 354 39 20 4.3 2.4 | -7.3 18.9 350 27 14 6.3 3.5
12500 -7.1 19.2 351 36 19 3.8 2.1 | -6.3 20.7 349 25 13 6.7 3.7
12000 -6.5 20.3 347 33 17 3.1 1.7 | -5.4 22.3 347 24 12 5.6 3.1
11500 -6.1 21.0 344 29 15 2.7 1.5 | -4.6 23.7 343 22 11 5.1 2.8
11000 -5.8 21.6 341 25 13 2.1 1.2 | -4.0 24.8 339 20 10 3.1 1.7
10500 -5.5 22.1 338 20 11 1.8 1.0 | -3.6 25.5 336 17 9 2.3 1.2
10250 -5.4 22.3 336 18 9 1.9 1.0 | -3.5 25.7 334 16 8 2.3 1.3
10000 -5.2 22.6 333 16 8 2.3 1.3 | -3.3 26.1 332 14 7 2.7 1.5
9750 -5.0 23.0 328 15 8 2.6 1.4 | -3.1 26.4 329 13 7 2.9 1.6
9500 -4.8 23.4 323 14 7 2.2 1.2 | -2.9 26.8 325 12 6 2.6 1.4
9250 -4.7 23.5 317 13 7 3.4 1.9 | -2.7 27.1 320 10 5 3.7 2.0
9000 -4.3 24.3 311 12 6 5.2 2.8 | -2.3 27.9 314 10 5 5.3 2.9
8750 -3.9 25.0 305 12 6 5.3 2.9 | -1.9 28.6 308 9 5 5.3 2.9
8500 -3.5 25.7 298 12 6 5.3 2.9 | -1.5 29.3 301 9 4 5.4 3.0
8250 -3.2 26.2 291 11 6 4.3 2.4 | -1.2 29.8 293 8 4 3.1 1.7
8000 -2.9 26.8 287 10 5 3.5 1.9 | -1.0 30.2 287 7 4 1.3 0.7
7750 -2.6 27.3 283 9 5 3.8 2.1 | -0.9 30.4 279 7 3 1.7 0.9
7500 -2.3 27.9 277 8 4 3.3 1.8 | -0.8 30.6 269 6 3 1.9 1.0
7250 -2.1 28.2 278 8 4 2.4 1.3 | -0.6 30.9 267 6 3 2.4 1.3
7000 -2.0 28.4 283 8 4 2.5 1.4 | -0.5 31.1 271 5 3 2.5 1.4
6750 -1.8 28.8 287 8 4 1.9 1.1 | -0.3 31.5 274 5 3 2.3 1.3
6500 -1.8 28.8 288 8 4 -1.8 -1.0 | -0.2 31.6 274 5 2 0.2 0.1
6250 -2.1 28.2 282 8 4 -4.0 -2.2 | -0.3 31.5 261 3 2 -0.3 -0.2
6000 -2.4 27.7 276 8 4 -3.2 -1.8 | -0.4 31.3 233 2 1 -1.5 -0.8
5750 -2.7 27.1 270 8 4 -4.3 -2.3 | -0.5 31.1 191 2 1 6.0 3.3
5500 -3.1 26.4 255 6 3 -5.8 -3.2 | 0.6 33.1 197 2 1 23.5 12.9
11/24/2009 AT 1400 MST | 11/24/2009 AT 1700 MST
|
K INDEX... -10.8 | K INDEX... -5.1
|
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 -59.0 -74.2 302 18 9 1.1 0.6 | -59.0 -74.2 296 19 10 0.9 0.5
45000 -57.3 -71.1 306 26 14 1.0 0.6 | -57.7 -71.9 304 24 12 0.8 0.5
40000 -60.5 -76.9 297 43 22 -2.3 -1.3 | -60.9 -77.6 308 42 22 -2.3 -1.3
38000 -61.0 -77.8 300 45 23 1.9 1.1 | -61.2 -78.2 311 45 23 2.3 1.3
36000 -59.8 -75.6 315 42 22 1.9 1.1 | -59.9 -75.8 319 40 21 2.3 1.2
34000 -58.5 -73.3 330 42 22 6.2 3.4 | -58.3 -72.9 329 36 19 6.4 3.5
32000 -54.0 -65.2 333 40 21 7.6 4.1 | -53.8 -64.8 329 37 19 7.5 4.1
30000 -49.4 -56.9 335 38 20 8.5 4.6 | -48.6 -55.5 329 38 20 8.4 4.6
29000 -46.3 -51.3 336 37 19 8.4 4.6 | -46.1 -51.0 329 38 19 8.4 4.6
28000 -43.7 -46.7 336 37 19 8.4 4.6 | -43.6 -46.5 328 37 19 8.4 4.6
27000 -41.2 -42.2 337 36 18 9.0 4.9 | -41.1 -42.0 327 36 19 8.9 4.9
26000 -38.4 -37.1 335 36 18 9.4 5.2 | -38.3 -36.9 326 35 18 9.2 5.1
25000 -35.6 -32.1 334 36 19 9.4 5.2 | -35.6 -32.1 325 34 18 9.2 5.1
24000 -32.8 -27.0 332 36 19 9.0 4.9 | -32.8 -27.0 324 34 17 8.9 4.9
23000 -30.3 -22.5 333 35 18 8.2 4.5 | -30.3 -22.5 325 33 17 8.3 4.6
22000 -27.9 -18.2 333 34 18 8.2 4.5 | -27.8 -18.0 326 32 17 8.3 4.6
21000 -25.4 -13.7 334 34 17 8.5 4.7 | -25.3 -13.5 327 32 16 8.8 4.8
20000 -22.9 -9.2 334 34 18 8.6 4.7 | -22.7 -8.9 329 31 16 8.9 4.9
19500 -21.6 -6.9 334 34 18 8.6 4.7 | -21.3 -6.3 331 30 15 8.9 4.9
19000 -20.3 -4.5 334 35 18 8.6 4.7 | -20.0 -4.0 332 29 15 8.9 4.9
18500 -19.0 -2.2 334 35 18 8.5 4.7 | -18.7 -1.7 333 29 15 8.5 4.7
18000 -17.8 -0.0 334 34 18 8.4 4.6 | -17.5 0.5 333 29 15 8.3 4.6
17500 -16.5 2.3 333 34 18 8.4 4.6 | -16.2 2.8 333 29 15 8.3 4.6
17000 -15.3 4.5 333 33 17 8.1 4.4 | -15.0 5.0 333 28 15 8.4 4.6
16500 -14.1 6.6 332 33 17 8.2 4.5 | -13.1 8.4 332 28 15 8.3 4.5
16000 -12.4 9.7 331 32 16 7.0 3.8 | -11.9 10.6 331 28 14 7.9 4.3
15500 -11.3 11.7 330 31 16 7.1 3.9 | -10.7 12.7 330 28 14 7.9 4.3
15000 -10.3 13.5 329 30 15 6.3 3.5 | -9.6 14.7 330 28 14 7.1 3.9
14500 -9.4 15.1 328 28 14 6.4 3.5 | -8.6 16.5 329 27 14 7.2 3.9
14000 -8.4 16.9 327 26 14 6.7 3.7 | -7.5 18.5 329 26 14 6.7 3.7
13500 -7.4 18.7 326 24 13 6.8 3.7 | -6.5 20.3 329 25 13 6.7 3.7
13000 -6.4 20.5 325 22 12 5.6 3.1 | -5.6 21.9 329 24 12 5.6 3.1
12500 -5.6 21.9 323 20 10 5.3 2.9 | -4.8 23.4 330 22 11 5.4 3.0
12000 -4.9 23.2 321 18 9 4.9 2.7 | -4.0 24.8 330 20 10 4.9 2.7
11500 -4.2 24.4 318 16 8 4.7 2.6 | -3.3 26.1 331 18 9 4.8 2.6
11000 -3.5 25.7 314 15 8 4.6 2.5 | -2.6 27.3 332 17 9 5.0 2.7
10500 -2.8 27.0 309 13 7 4.6 2.5 | -1.8 28.8 331 16 8 5.1 2.8
10250 -2.4 27.7 306 13 6 4.7 2.6 | -1.4 29.5 331 15 8 4.8 2.6
10000 -2.1 28.2 304 12 6 5.0 2.7 | -1.1 30.0 330 14 7 4.2 2.3
9750 -1.7 28.9 303 13 6 5.0 2.7 | -0.8 30.6 328 14 7 4.0 2.2
9500 -1.3 29.7 301 13 7 5.3 2.9 | -0.5 31.1 326 13 7 4.1 2.2
9250 -1.0 30.2 300 13 7 4.1 2.3 | -0.2 31.6 324 13 7 4.0 2.2
9000 -0.7 30.7 300 12 6 2.7 1.5 | 0.1 32.2 322 12 6 3.8 2.1
8750 -0.6 30.9 300 11 6 2.8 1.5 | 0.4 32.7 320 11 6 3.9 2.1
8500 -0.4 31.3 300 11 5 2.8 1.5 | 0.6 33.1 318 11 6 3.8 2.1
8250 -0.1 31.8 300 10 5 3.4 1.9 | 0.9 33.6 315 10 5 2.6 1.4
8000 0.1 32.2 302 9 4 3.7 2.1 | 1.0 33.8 314 9 5 1.8 1.0
7750 0.4 32.7 304 8 4 3.8 2.1 | 1.1 34.0 313 8 4 2.0 1.1
7500 0.7 33.3 307 7 3 3.1 1.7 | 1.2 34.2 311 7 3 2.4 1.3
7250 0.8 33.4 307 5 3 1.9 1.0 | 1.4 34.5 306 6 3 2.9 1.6
7000 1.0 33.8 306 4 2 1.7 0.9 | 1.6 34.9 297 5 3 3.0 1.6
6750 1.1 34.0 303 2 1 1.9 1.0 | 1.8 35.2 286 4 2 2.9 1.6
6500 1.2 34.2 294 1 0 3.1 1.7 | 2.0 35.6 274 4 2 2.5 1.4
6250 1.5 34.7 000 0 0 4.2 2.3 | 2.2 36.0 265 4 2 1.8 1.0
6000 1.7 35.1 000 0 0 3.1 1.7 | 2.4 36.3 254 3 2 3.3 1.8
5750 1.9 35.4 138 1 0 7.2 4.0 | 2.5 36.5 241 3 1 -1.9 -1.1
5500 2.8 37.0 111 1 0 16.7 9.1 | 1.8 35.2 251 2 1 -14.4 -7.9
________________________________________________________________________________
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:
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 - 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, CIRROSTATUS, 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.
071806
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