310
UXUS97 KPUB 241109
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO CO
509 AM MDT THU JUL 24 2008
EXPERIMENTAL PRODUCT
THIS FORECAST IS FOR THURSDAY JULY 24, 2008:
IF THE TRIGGER TEMPERATURE OF 76.2 F/24.6 C IS REACHED...THEN
THERMAL SOARING INDEX....................... EXCELLENT
MAXIMUM RATE OF LIFT........................ 1048 FT/MIN (5.3 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 19516 FT MSL (12346 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 88.0 F/31.6 C
TIME OF TRIGGER TEMPERATURE.................... 1000 MDT
TIME OF OVERDEVELOPMENT........................ 1500 MDT
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... OVERCAST THIN HIGH
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 16365 FT MSL (9195 FT AGL)
THERMAL SOARING OUTLOOK FOR FRIDAY 07/25....... EXCELLENT
WAVE SOARING INDEX............................. POOR
WAVE SOARING INDEX TREND (TO 1800 MDT)......... DECREASE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1800 MDT)................ NEITHER
POTENTIAL HEIGHT OF WAVE....................... 28298 FT MSL (21128 FT AGL)
WAVE SOARING OUTLOOK FOR FRIDAY 07/25.......... POOR
REMARKS...
SUNRISE/SUNSET.................... 05:53:37 / 20:18:10 MDT
TOTAL POSSIBLE SUNSHINE........... 14 HR 24 MIN 34 SEC (864 MIN 34 SEC)
ALTITUDE OF SUN AT 13:05:44 MDT... 70.66 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 07/24/2008 AT 0600 MDT
FREEZING LEVEL.................. 17151 FT MSL (9981 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 17401 FT MSL (10231 FT AGL)
LIFTED CONDENSATION LEVEL....... 17922 FT MSL (10752 FT AGL)
LIFTED INDEX.................... -2.0
K INDEX......................... +17.0
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 -67.1 -88.8 263 11 6 2.4 1.3 69.1 156.5 22.9 M M
45000 -61.0 -77.8 263 21 11 6.7 3.7 56.1 133.0 16.1 M M
40000 -50.5 -58.9 257 28 14 8.5 4.7 50.3 122.6 13.3 M M
38000 -44.8 -48.6 258 27 14 8.5 4.7 49.0 120.3 12.7 M M
36000 -39.7 -39.5 258 26 14 7.9 4.3 48.2 118.8 12.4 M M
34000 -35.0 -31.0 254 25 13 8.0 4.4 46.6 115.8 11.5 M M
32000 -30.3 -22.5 249 24 12 7.7 4.2 45.5 113.9 10.9 M M
30000 -25.9 -14.6 258 21 11 7.5 4.1 43.5 110.2 9.5 M M
29000 -23.7 -10.7 263 21 11 7.5 4.1 42.7 108.8 9.0 M M
28000 -21.5 -6.7 268 20 10 7.1 3.9 41.9 107.3 8.4 M M
27000 -19.4 -2.9 272 20 10 7.1 3.9 40.8 105.4 7.6 M M
26000 -17.3 0.9 277 20 10 7.1 3.9 39.8 103.7 6.9 M M
25000 -15.1 4.8 282 20 10 6.8 3.7 39.0 102.2 6.2 M M
24000 -13.3 8.1 286 19 10 6.2 3.4 37.6 99.7 5.2 M M
23000 -10.9 12.4 292 17 9 6.2 3.4 36.1 96.9 3.9 M M
22000 -9.1 15.6 297 16 8 5.7 3.1 34.8 94.7 2.9 M M
21000 -7.4 18.7 304 14 7 5.7 3.1 33.4 92.1 1.7 M M
20000 -5.7 21.7 312 13 7 5.8 3.2 32.0 89.6 0.5 M M
19500 -4.9 23.2 318 12 6 6.6 3.6 31.4 88.5 -0.1 1143 5.8
19000 -3.7 25.3 320 12 6 7.9 4.3 31.0 87.9 -0.4 1094 5.6
18500 -2.6 27.3 323 12 6 8.1 4.4 30.7 87.3 -0.7 1044 5.3
18000 -1.5 29.3 324 12 6 6.3 3.5 30.3 86.6 -1.1 997 5.1
17500 -0.6 30.9 324 13 6 6.3 3.5 29.7 85.5 -1.7 956 4.9
17000 0.3 32.5 323 13 7 6.4 3.5 29.2 84.5 -2.2 915 4.6
16500 1.2 34.2 322 13 6 6.6 3.6 28.6 83.5 -2.8 873 4.4
16000 2.1 35.8 322 12 6 6.6 3.6 28.1 82.6 -3.4 832 4.2
15500 3.1 37.6 319 12 6 7.8 4.3 27.7 81.9 -3.9 787 4.0
15000 4.2 39.6 313 11 5 7.7 4.2 27.4 81.3 -4.3 739 3.8
14500 5.3 41.5 306 10 5 8.3 4.5 27.1 80.8 -4.6 691 3.5
14000 6.5 43.7 297 9 5 8.4 4.6 26.9 80.4 -4.9 639 3.2
13500 7.8 46.0 287 9 4 8.5 4.7 26.7 80.0 -5.1 587 3.0
13000 9.0 48.2 278 10 5 8.5 4.7 26.5 79.7 -5.3 535 2.7
12500 10.3 50.5 271 11 6 8.5 4.6 26.3 79.3 -5.6 482 2.4
12000 11.5 52.7 267 12 6 8.2 4.5 26.1 78.9 -5.8 431 2.2
11750 12.1 53.8 266 12 6 8.3 4.5 25.9 78.7 -6.0 405 2.1
11500 12.7 54.9 264 13 6 8.3 4.5 25.8 78.5 -6.1 379 1.9
11250 13.3 55.9 263 13 7 8.4 4.6 25.7 78.3 -6.2 354 1.8
11000 14.0 57.2 262 13 7 8.5 4.7 25.6 78.1 -6.3 328 1.7
10750 14.6 58.3 260 14 7 8.5 4.6 25.5 77.9 -6.5 302 1.5
10500 15.2 59.4 259 14 7 8.5 4.7 25.4 77.8 -6.6 276 1.4
10250 15.8 60.4 258 14 7 7.8 4.3 25.3 77.6 -6.7 250 1.3
10000 16.3 61.3 255 14 7 7.3 4.0 25.1 77.2 -7.0 227 1.2
9750 16.8 62.2 253 13 7 7.5 4.1 25.0 76.9 -7.2 204 1.0
9500 17.9 64.2 248 12 6 6.8 3.7 24.6 76.3 -7.6 158 0.8
9250 18.3 64.9 248 12 6 6.3 3.5 24.3 75.8 -7.9 138 0.7
9000 18.8 65.8 249 12 6 6.6 3.6 24.1 75.4 -8.2 117 0.6
8750 19.2 66.6 249 12 6 6.0 3.3 23.8 74.9 -8.5 96 0.5
8500 19.5 67.1 251 12 6 2.9 1.6 23.5 74.2 -9.0 79 0.4
8250 19.6 67.3 256 13 7 0.3 0.2 22.8 73.1 -9.7 71 0.4
8000 19.6 67.3 261 13 7 3.7 2.0 22.2 71.9 -10.4 62 0.3
7750 19.7 67.5 265 14 7 -7.0 -3.8 21.6 70.8 -11.1 53 0.3
7500 17.9 64.2 268 13 7 -39.0 -21.4 19.6 67.2 -13.2 98 0.5
7250 14.8 58.6 270 10 5 -25.8 -14.2 16.5 61.7 -16.3 183 0.9
7000 M M M M M M M M M M M M
6750 M M M M M M M M M M M M
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
07/24/2008 AT 0900 MDT | 07/24/2008 AT 1200 MDT
|
K INDEX... +13.6 | K INDEX... +18.7
|
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 -65.8 -86.4 252 9 5 1.8 1.0 | -67.0 -88.6 255 11 6 2.3 1.3
45000 -60.4 -76.7 272 21 11 6.5 3.6 | -60.6 -77.1 271 19 10 7.4 4.1
40000 -50.2 -58.4 265 28 14 8.1 4.5 | -49.3 -56.7 259 26 13 7.9 4.3
38000 -44.8 -48.6 263 27 14 8.1 4.5 | -44.0 -47.2 256 24 12 7.9 4.3
36000 -39.9 -39.8 261 26 14 7.7 4.2 | -39.3 -38.7 253 23 12 7.4 4.1
34000 -35.4 -31.7 258 25 13 7.7 4.2 | -34.8 -30.6 247 23 12 7.4 4.1
32000 -30.8 -23.4 255 24 12 7.5 4.1 | -30.4 -22.7 241 24 12 7.1 3.9
30000 -26.7 -16.1 264 20 10 6.9 3.8 | -26.4 -15.5 249 20 10 6.7 3.7
29000 -24.6 -12.3 270 18 9 6.9 3.8 | -24.5 -12.1 253 19 10 6.7 3.7
28000 -22.6 -8.7 276 17 9 6.9 3.8 | -22.4 -8.3 259 17 9 7.3 4.0
27000 -20.6 -5.1 280 16 8 6.9 3.8 | -20.3 -4.5 267 16 8 7.2 4.0
26000 -18.5 -1.3 285 15 8 6.9 3.8 | -18.1 -0.6 275 15 8 7.2 4.0
25000 -16.5 2.3 290 14 7 6.8 3.7 | -15.9 3.4 285 14 7 7.0 3.9
24000 -14.1 6.6 281 12 6 6.6 3.6 | -13.4 7.9 283 12 6 6.8 3.7
23000 -12.1 10.2 270 10 5 6.6 3.6 | -11.4 11.5 280 11 6 6.8 3.7
22000 -10.2 13.6 258 8 4 5.9 3.3 | -9.5 14.9 273 10 5 6.6 3.6
21000 -8.4 16.9 262 7 4 5.9 3.2 | -7.5 18.5 257 11 6 6.7 3.7
20000 -6.7 19.9 267 6 3 6.0 3.3 | -5.6 21.9 244 13 7 6.6 3.6
19500 -5.8 21.6 270 6 3 6.5 3.6 | -4.6 23.7 239 14 7 6.2 3.4
19000 -4.7 23.5 280 6 3 7.5 4.1 | -3.7 25.3 242 14 7 5.7 3.1
18500 -3.6 25.5 289 7 3 7.6 4.2 | -2.9 26.8 245 13 7 5.7 3.2
18000 -2.5 27.5 297 8 4 7.0 3.8 | -2.1 28.2 251 12 6 5.3 2.9
17500 -1.5 29.3 302 9 5 7.0 3.8 | -1.3 29.7 261 11 6 5.4 2.9
17000 -0.4 31.3 306 11 6 7.2 4.0 | -0.6 30.9 272 11 6 6.1 3.3
16500 0.7 33.3 307 12 6 7.8 4.3 | 0.4 32.7 286 10 5 7.2 4.0
16000 1.8 35.2 309 12 6 7.7 4.2 | 1.4 34.5 304 9 5 7.2 3.9
15500 3.0 37.4 311 13 7 8.3 4.5 | 2.6 36.7 317 9 5 9.6 5.3
15000 4.2 39.6 314 13 7 8.3 4.5 | 3.9 39.0 324 8 4 9.4 5.2
14500 5.4 41.7 317 13 7 8.7 4.8 | 5.3 41.5 331 8 4 9.8 5.4
14000 6.7 44.1 319 13 7 8.9 4.9 | 6.8 44.2 333 8 4 9.9 5.4
13500 8.0 46.4 321 14 7 9.0 4.9 | 8.3 46.9 336 8 4 9.8 5.4
13000 9.3 48.7 323 14 7 9.1 5.0 | 9.7 49.5 338 8 4 9.6 5.3
12500 10.7 51.3 325 15 7 9.0 4.9 | 11.2 52.2 341 8 4 9.7 5.3
12000 12.0 53.6 327 14 7 8.8 4.8 | 12.6 54.7 342 8 4 10.0 5.5
11750 12.6 54.7 328 14 7 8.8 4.8 | 13.4 56.1 343 8 4 10.0 5.5
11500 13.3 55.9 329 14 7 8.8 4.8 | 14.1 57.4 344 8 4 10.0 5.5
11250 13.9 57.0 329 14 7 8.5 4.7 | 14.9 58.8 345 8 4 9.9 5.4
11000 14.6 58.3 326 13 7 8.4 4.6 | 15.6 60.1 346 8 4 9.8 5.4
10750 15.2 59.4 323 12 6 8.4 4.6 | 16.3 61.3 347 8 4 9.8 5.4
10500 15.8 60.4 319 11 6 8.4 4.6 | 17.1 62.8 348 8 4 9.8 5.4
10250 16.4 61.5 315 11 6 7.8 4.3 | 17.8 64.0 349 8 4 10.0 5.5
10000 16.9 62.4 311 11 6 7.4 4.1 | 18.6 65.5 350 8 4 10.2 5.6
9750 17.9 64.2 302 11 6 7.6 4.1 | 20.1 68.2 352 8 4 10.1 5.6
9500 18.4 65.1 298 11 6 8.3 4.5 | 20.8 69.4 353 8 4 10.1 5.6
9250 19.0 66.2 296 11 6 8.8 4.8 | 21.6 70.9 354 8 4 10.1 5.6
9000 19.6 67.3 295 11 6 8.7 4.8 | 22.3 72.1 355 8 4 10.1 5.6
8750 20.2 68.4 294 12 6 8.8 4.8 | 23.1 73.6 356 8 4 10.1 5.6
8500 20.8 69.4 293 11 6 9.1 5.0 | 23.8 74.8 357 8 4 9.9 5.4
8250 21.5 70.7 293 11 6 9.4 5.2 | 24.6 76.3 358 7 4 10.1 5.5
8000 22.2 72.0 293 10 5 9.1 5.0 | 25.3 77.5 359 7 4 9.2 5.1
7750 22.8 73.0 294 10 5 10.1 5.5 | 26.0 78.8 360 7 4 12.5 6.9
7500 23.6 74.5 293 9 5 12.9 7.1 | 27.3 81.1 360 7 4 23.0 12.6
7250 24.6 76.3 291 9 5 11.6 6.4 | 29.1 84.4 357 7 4 20.1 11.0
7000 M M M M M M M | M M M M M M M
6750 M M M M M M M | M M M M M M M
07/24/2008 AT 1500 MDT | 07/24/2008 AT 1800 MDT
|
K INDEX... +27.9 | K INDEX... +30.3
|
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 -67.1 -88.8 239 15 7 2.1 1.2 | -67.4 -89.3 236 20 10 2.2 1.2
45000 -60.8 -77.4 246 20 10 7.4 4.1 | -60.8 -77.4 237 25 13 7.7 4.2
40000 -49.5 -57.1 237 28 14 8.1 4.5 | -49.3 -56.7 230 27 14 7.8 4.3
38000 -44.0 -47.2 234 26 13 8.1 4.5 | -44.6 -48.3 232 26 13 7.8 4.3
36000 -39.2 -38.6 233 25 13 7.4 4.1 | -39.9 -39.8 235 25 13 7.8 4.3
34000 -34.7 -30.5 235 25 13 7.5 4.1 | -34.6 -30.3 236 24 12 7.9 4.3
32000 -30.3 -22.5 237 24 13 7.1 3.9 | -30.0 -22.0 236 23 12 7.3 4.0
30000 -26.4 -15.5 245 20 10 6.6 3.6 | -25.8 -14.4 239 19 10 7.1 3.9
29000 -24.4 -11.9 250 18 9 6.6 3.6 | -23.7 -10.7 241 17 9 7.1 3.9
28000 -22.4 -8.3 256 16 8 7.1 3.9 | -21.7 -7.1 246 15 8 6.1 3.4
27000 -20.3 -4.5 261 14 7 7.1 3.9 | -19.9 -3.8 258 14 7 6.2 3.4
26000 -18.2 -0.8 266 13 7 7.1 3.9 | -18.1 -0.6 270 15 8 6.2 3.4
25000 -16.1 3.0 272 12 6 6.6 3.6 | -16.3 2.7 280 15 8 6.1 3.3
24000 -13.9 7.0 266 14 7 6.1 3.3 | -14.5 5.9 282 13 7 6.0 3.3
23000 -12.1 10.2 262 15 8 6.1 3.4 | -12.8 9.0 283 11 6 6.0 3.3
22000 -10.4 13.3 260 15 8 5.4 3.0 | -11.0 12.2 286 9 5 6.6 3.6
21000 -8.9 16.0 263 14 7 5.6 3.1 | -9.0 15.8 302 6 3 6.9 3.8
20000 -7.3 18.9 267 13 7 5.7 3.1 | -7.1 19.2 337 5 2 6.9 3.8
19500 -6.5 20.3 270 12 6 7.2 4.0 | -6.1 21.0 001 5 2 6.9 3.8
19000 -5.3 22.5 275 10 5 8.5 4.7 | -5.1 22.8 016 5 2 6.7 3.7
18500 -4.0 24.8 285 7 4 8.6 4.7 | -4.1 24.6 028 5 3 6.8 3.7
18000 -2.8 27.0 300 6 3 8.8 4.8 | -2.5 27.5 039 6 3 8.8 4.8
17500 -1.5 29.3 318 5 2 8.8 4.8 | -1.2 29.8 042 6 3 8.7 4.7
17000 -0.2 31.6 343 4 2 9.0 4.9 | 0.1 32.2 045 6 3 9.4 5.2
16500 1.2 34.2 354 4 2 9.1 5.0 | 1.6 34.9 046 6 3 9.7 5.3
16000 2.5 36.5 005 5 2 9.1 5.0 | 3.0 37.4 048 6 3 9.7 5.3
15500 3.9 39.0 012 5 3 9.3 5.1 | 4.4 39.9 052 6 3 9.5 5.2
15000 5.3 41.5 018 5 3 9.3 5.1 | 5.9 42.6 057 6 3 9.5 5.2
14500 6.7 44.1 024 6 3 9.8 5.4 | 7.3 45.1 061 6 3 9.9 5.4
14000 8.1 46.6 028 6 3 9.9 5.4 | 8.8 47.8 064 6 3 9.9 5.4
13500 9.6 49.3 031 6 3 9.8 5.4 | 10.2 50.4 068 6 3 9.7 5.3
13000 11.1 52.0 034 6 3 9.8 5.4 | 11.7 53.1 072 6 3 9.7 5.3
12500 12.5 54.5 037 7 3 9.8 5.4 | 13.1 55.6 077 6 3 9.6 5.3
12000 14.0 57.2 040 7 4 9.8 5.4 | 14.5 58.1 082 6 3 9.6 5.3
11750 14.7 58.5 041 7 4 9.8 5.4 | 15.3 59.5 084 6 3 9.5 5.2
11500 15.5 59.9 042 7 4 9.8 5.4 | 16.0 60.8 087 6 3 9.7 5.3
11250 16.2 61.2 043 7 4 9.8 5.4 | 16.7 62.1 089 6 3 10.0 5.5
11000 16.9 62.4 044 7 4 9.8 5.4 | 17.5 63.5 091 6 3 10.0 5.5
10750 17.7 63.9 045 7 4 9.8 5.4 | 18.2 64.8 093 6 3 10.0 5.5
10500 18.4 65.1 045 8 4 9.8 5.4 | 18.9 66.0 095 6 3 9.8 5.4
10250 19.2 66.6 046 8 4 10.0 5.5 | 19.7 67.5 097 6 3 9.5 5.2
10000 19.9 67.8 047 8 4 10.1 5.5 | 20.4 68.7 099 6 3 9.5 5.2
9750 21.4 70.5 050 8 4 10.1 5.5 | 21.1 70.0 101 6 3 9.5 5.2
9500 22.2 72.0 051 8 4 10.4 5.7 | 21.8 71.2 103 6 3 9.6 5.3
9250 22.9 73.2 052 8 4 10.6 5.8 | 22.5 72.5 106 6 3 9.9 5.4
9000 23.7 74.7 053 8 4 10.5 5.8 | 23.2 73.8 109 6 3 9.9 5.4
8750 24.5 76.1 054 8 4 10.5 5.8 | 23.9 75.0 112 6 3 9.9 5.4
8500 25.3 77.5 055 8 4 10.4 5.7 | 24.7 76.5 115 6 3 10.0 5.5
8250 26.0 78.8 056 8 4 10.5 5.8 | 25.4 77.7 115 6 3 10.2 5.6
8000 26.8 80.2 058 8 4 10.1 5.5 | 26.0 78.8 113 5 3 10.2 5.6
7750 27.6 81.7 059 8 4 11.7 6.4 | 26.7 80.1 112 5 3 10.3 5.6
7500 28.6 83.5 058 8 4 17.3 9.5 | M M M M M M M
7250 29.9 85.8 054 8 4 17.2 9.4 | M M M M M M M
7000 M M M M M M M | M M M M M M M
6750 M M M M M M M | M M M M M M M
________________________________________________________________________________
THIS PRODUCT IS ISSUED ONE PER DAY BY APPROXIMATELY 0630 MST/0730 MDT
(1330 UTC). IT IS NOT CONTINUOUSLY MONITORED NOR UPDATED AFTER ITS INITIAL
ISSUANCE.
THE INFORMATION CONTAINED HEREIN IS BASED ON NUMERICAL WEATHER PREDICTION
MODEL DATA TAKEN NEAR THE AIR FORCE ACADEMY IN COLORADO SPRINGS, COLORADO
AT
NORTH LATITUDE: 38 DEG 58 MIN 48.000 SEC
WEST LONGITUDE: 104 DEG 49 MIN 12.000 SEC
ELEVATION: 6572 FEET (2003 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.
AT THIS TIME, THE OUTPUT FROM THIS CONSIDERED EXPERIMENTAL.
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.
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