289
UXUS97 KBOU 081241
SRGBOU
SOARING FORECAST
NATIONAL WEATHER SERVICE DENVER/BOULDER, COLORADO
541 AM MST SUNDAY NOVEMBER 8, 2009
THIS FORECAST IS FOR SUNDAY NOVEMBER 8, 2009:
IF THE TRIGGER TEMPERATURE OF 68.6 F/20.3 C IS REACHED...THEN
THERMAL SOARING INDEX....................... POOR
MAXIMUM RATE OF LIFT........................ 0 FT/MIN (0.0 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 6825 FT MSL (1540 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 63.0 F/17.7 C
TIME OF TRIGGER TEMPERATURE.................... NONE
TIME OF OVERDEVELOPMENT........................ NONE
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... BROKEN/OVERCAST OPAQUE MIDDLE
SURFACE WINDS DURING SOARING WINDOW............ 20 MPH OR LESS
HEIGHT OF THE -3 THERMAL INDEX................. 5898 FT MSL (613 FT AGL)
THERMAL SOARING OUTLOOK FOR MONDAY 11/09....... POOR
WAVE SOARING INDEX............................. FAIR
WAVE SOARING INDEX TREND (TO 1700 MST)......... LITTLE CHANGE
HEIGHT OF STABLE LAYER (12-18K FT MSL)......... NONE
WEAK PVA/NVA (THROUGH 1700 MST)................ NEITHER
POTENTIAL HEIGHT OF WAVE....................... 15616 FT MSL (10331 FT AGL)
WAVE SOARING OUTLOOK FOR MONDAY 11/09.......... FAIR
REMARKS...
SUNRISE/SUNSET.................... 06:36:30 / 16:49:49 MST
TOTAL POSSIBLE SUNSHINE........... 10 HR 13 MIN 19 SEC (613 MIN 19 SEC)
ALTITUDE OF SUN AT 11:43:23 MST... 33.50 DEGREES
UPPER AIR DATA FROM RAWINSONDE OBSERVATION TAKEN ON 11/08/2009 AT 0500 MST
FREEZING LEVEL.................. 12229 FT MSL (6944 FT AGL)
CONVECTIVE CONDENSATION LEVEL... 19235 FT MSL (13950 FT AGL)
LIFTED CONDENSATION LEVEL....... 15807 FT MSL (10521 FT AGL)
LIFTED INDEX.................... +5.6
K INDEX......................... +1.9
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 -63.5 -82.3 234 59 30 -13.7 -7.5 94.6 202.2 43.7 M M
45000 -61.2 -78.2 217 57 29 2.1 1.1 71.8 161.2 33.3 M M
40000 -61.8 -79.2 240 50 26 9.5 5.2 47.5 117.5 19.9 M M
38000 -57.9 -72.2 240 54 28 6.5 3.6 44.3 111.7 18.3 M M
36000 -53.9 -65.0 233 57 29 7.1 3.9 41.6 106.9 16.9 M M
34000 -50.2 -58.4 231 61 32 9.8 5.4 38.6 101.4 15.2 M M
32000 -46.1 -51.0 229 60 31 8.5 4.6 36.2 97.1 13.9 M M
30000 -40.8 -41.4 219 53 27 6.8 3.7 34.6 94.3 13.1 M M
29000 -38.5 -37.3 218 52 27 9.2 5.1 33.8 92.8 12.6 M M
28000 -35.8 -32.4 217 52 27 9.1 5.0 33.5 92.3 12.6 M M
27000 -33.1 -27.6 217 51 26 7.2 3.9 33.2 91.7 12.4 M M
26000 -31.0 -23.8 215 51 26 7.1 3.9 32.1 89.8 11.7 M M
25000 -28.9 -20.0 215 50 26 7.3 4.0 31.2 88.1 11.1 M M
24000 -26.7 -16.1 215 51 26 5.2 2.8 30.3 86.5 10.6 M M
23000 -25.2 -13.4 215 47 24 4.3 2.4 28.6 83.5 9.2 M M
22000 -22.9 -9.2 217 43 22 8.8 4.8 27.8 82.0 8.6 M M
21000 -20.4 -4.7 218 38 20 8.6 4.7 27.4 81.2 8.4 M M
20000 -17.8 -0.0 219 34 18 8.6 4.7 27.0 80.7 8.2 M M
19500 -16.5 2.3 225 34 17 8.7 4.8 26.8 80.2 8.0 M M
19000 -15.2 4.6 231 34 17 9.3 5.1 26.6 79.9 7.9 M M
18500 -13.7 7.3 235 34 17 8.8 4.8 26.6 79.9 7.9 M M
18000 -12.5 9.5 236 33 17 8.1 4.4 26.3 79.3 7.7 M M
17500 -11.4 11.5 236 33 17 7.3 4.0 25.9 78.7 7.4 M M
17000 -10.3 13.5 237 32 17 7.4 4.1 25.5 77.9 7.1 M M
16500 -9.1 15.6 238 32 16 7.5 4.1 25.1 77.2 6.8 M M
16000 -8.1 17.4 239 31 16 5.3 2.9 24.7 76.4 6.5 M M
15500 -7.4 18.7 247 31 16 4.9 2.7 23.8 74.9 5.8 M M
15000 -6.3 20.7 259 31 16 4.7 2.6 22.6 72.7 4.7 M M
14500 -5.7 21.7 254 26 13 4.1 2.2 21.8 71.2 3.9 M M
14000 -4.7 23.5 250 21 11 9.5 5.2 21.2 70.2 3.4 M M
13500 -3.3 26.1 255 19 10 9.3 5.1 21.2 70.1 3.3 M M
13000 -1.9 28.6 261 17 9 9.3 5.1 21.1 70.0 3.3 M M
12500 -0.5 31.1 267 15 8 9.3 5.1 21.1 69.9 3.3 M M
12000 0.9 33.6 273 14 7 9.3 5.1 21.0 69.9 3.3 M M
11500 2.2 36.0 263 14 7 9.3 5.1 21.0 69.7 3.2 M M
11000 3.6 38.5 255 14 7 9.3 5.1 20.9 69.6 3.2 M M
10500 5.0 41.0 261 17 9 9.3 5.1 20.8 69.4 3.1 M M
10250 5.7 42.3 263 18 9 9.3 5.1 20.7 69.3 3.1 M M
10000 6.4 43.5 264 20 10 9.4 5.2 20.7 69.3 3.0 M M
9750 7.1 44.8 260 20 10 9.5 5.2 20.7 69.2 3.0 M M
9500 7.8 46.0 257 20 10 9.4 5.2 20.7 69.2 3.0 M M
9250 8.6 47.5 253 20 10 9.4 5.2 20.6 69.2 3.0 M M
9000 9.3 48.7 250 20 10 9.5 5.2 20.6 69.1 3.0 M M
8750 10.0 50.0 250 18 9 9.4 5.2 20.6 69.1 3.0 M M
8500 10.7 51.3 250 17 9 9.7 5.3 20.6 69.0 3.0 M M
8250 11.4 52.5 250 15 8 8.7 4.8 20.6 69.0 2.9 M M
8000 11.9 53.4 249 14 7 5.1 2.8 20.3 68.6 2.7 M M
7750 12.2 54.0 245 11 6 3.3 1.8 19.9 67.8 2.3 M M
7500 12.4 54.3 239 9 5 4.2 2.3 19.4 67.5 1.8 M M
7250 12.7 54.9 229 7 4 2.5 1.4 19.0 66.1 1.4 M M
7000 12.7 54.9 210 5 3 -0.5 -0.3 18.3 64.9 0.6 M M
6750 12.6 54.7 217 4 2 -1.1 -0.6 17.5 63.4 -0.2 76 0.4
6500 12.5 54.5 229 3 1 -0.6 -0.3 16.6 62.0 -1.1 73 0.4
6250 12.3 54.1 254 2 1 -1.7 -0.9 15.8 60.5 -1.9 69 0.4
6000 12.2 54.0 291 2 1 2.8 1.6 15.1 59.1 -2.8 66 0.3
5750 12.6 54.7 273 2 1 5.6 3.1 14.8 58.6 -3.2 48 0.2
5500 11.7 53.1 244 2 1 -36.3 -19.9 13.3 56.0 -4.8 67 0.3
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
11/08/2009 AT 0800 MST | 11/08/2009 AT 1100 MST
|
K INDEX... +0.5 | K INDEX... +0.0
|
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 -63.8 -82.8 232 46 24 0.0 0.0 | -63.3 -81.9 230 54 28 -0.2 -0.1
45000 -63.7 -82.7 232 54 28 1.7 1.0 | -63.5 -82.3 227 62 32 1.5 0.8
40000 -61.0 -77.8 251 63 32 1.7 1.0 | -61.0 -77.8 246 66 34 1.6 0.9
38000 -58.1 -72.6 248 62 32 6.7 3.7 | -58.2 -72.8 243 66 34 6.6 3.6
36000 -54.0 -65.2 239 59 30 6.7 3.7 | -54.2 -65.6 235 65 33 6.6 3.6
34000 -49.8 -57.6 232 57 29 7.8 4.3 | -50.1 -58.2 229 64 33 7.5 4.1
32000 -44.5 -48.1 230 56 29 7.9 4.3 | -45.0 -49.0 230 63 32 7.5 4.1
30000 -40.0 -40.0 229 54 28 7.0 3.8 | -40.7 -41.3 231 60 31 6.9 3.8
29000 -37.9 -36.2 229 52 27 7.0 3.8 | -38.6 -37.5 233 58 30 6.9 3.8
28000 -35.8 -32.4 229 50 26 7.0 3.9 | -36.6 -33.9 235 55 28 6.9 3.8
27000 -33.7 -28.7 229 48 25 6.5 3.6 | -34.5 -30.1 236 53 27 7.1 3.9
26000 -31.8 -25.2 232 45 23 6.5 3.6 | -32.4 -26.3 237 49 25 7.0 3.9
25000 -29.9 -21.8 236 43 22 6.5 3.6 | -30.3 -22.5 237 46 24 7.0 3.9
24000 -27.9 -18.2 239 41 21 7.4 4.0 | -28.1 -18.6 237 43 22 8.1 4.4
23000 -25.6 -14.1 237 38 19 7.7 4.2 | -25.6 -14.1 234 40 20 8.4 4.6
22000 -23.3 -9.9 233 35 18 7.7 4.2 | -23.1 -9.6 231 37 19 8.5 4.6
21000 -20.9 -5.6 231 32 17 9.0 4.9 | -20.6 -5.1 228 35 18 8.3 4.6
20000 -18.3 -0.9 231 29 15 8.9 4.9 | -18.1 -0.6 230 32 17 8.3 4.6
19500 -16.9 1.6 231 28 14 8.9 4.9 | -16.8 1.8 231 31 16 8.3 4.6
19000 -15.6 3.9 231 27 14 8.9 4.9 | -15.6 3.9 232 30 15 8.4 4.6
18500 -14.3 6.3 231 25 13 8.3 4.6 | -14.3 6.3 233 29 15 7.6 4.2
18000 -13.0 8.6 233 24 12 8.2 4.5 | -13.2 8.2 235 27 14 7.4 4.1
17500 -11.8 10.8 235 22 11 8.1 4.4 | -12.1 10.2 236 26 13 7.2 4.0
17000 -10.1 13.8 241 21 11 7.7 4.2 | -10.7 12.7 238 23 12 6.4 3.5
16500 -8.9 16.0 245 21 11 7.8 4.3 | -9.7 14.5 239 21 11 6.4 3.5
16000 -7.7 18.1 248 20 10 8.0 4.4 | -8.8 16.2 240 19 10 6.4 3.5
15500 -6.5 20.3 251 20 10 8.0 4.4 | -7.8 18.0 241 17 9 6.4 3.5
15000 -5.4 22.3 254 19 10 7.0 3.8 | -6.8 19.8 243 16 8 6.7 3.7
14500 -4.4 24.1 257 17 9 7.0 3.8 | -5.9 21.4 247 14 7 6.7 3.7
14000 -3.3 26.1 261 17 9 7.7 4.2 | -4.9 23.2 252 13 7 6.4 3.5
13500 -2.1 28.2 265 16 8 7.8 4.3 | -4.0 24.8 260 12 6 6.4 3.5
13000 -1.0 30.2 270 16 8 7.5 4.1 | -3.0 26.6 269 11 6 6.4 3.5
12500 0.1 32.2 275 17 9 7.3 4.0 | -2.1 28.2 277 12 6 6.4 3.5
12000 1.2 34.2 280 18 9 6.9 3.8 | -1.1 30.0 286 12 6 6.5 3.6
11500 2.2 36.0 285 20 10 6.7 3.7 | -0.2 31.6 290 14 7 6.5 3.6
11000 3.1 37.6 289 22 11 6.5 3.6 | 0.7 33.3 294 15 8 6.7 3.7
10500 4.1 39.4 292 25 13 6.4 3.5 | 1.7 35.1 298 16 8 6.8 3.7
10250 4.5 40.1 293 26 14 6.5 3.5 | 2.2 36.0 299 17 9 6.9 3.8
10000 5.0 41.0 293 28 14 6.3 3.5 | 2.7 36.9 301 17 9 7.2 3.9
9750 5.4 41.7 294 28 15 6.2 3.4 | 3.3 37.9 303 17 9 7.3 4.0
9500 5.9 42.6 294 29 15 6.2 3.4 | 3.8 38.8 306 17 9 7.3 4.0
9250 6.3 43.3 294 30 15 6.3 3.4 | 4.3 39.7 308 17 9 7.3 4.0
9000 6.8 44.2 295 30 16 6.6 3.6 | 4.9 40.8 311 16 8 7.2 3.9
8750 7.3 45.1 296 30 15 6.9 3.8 | 5.4 41.7 314 15 8 7.1 3.9
8500 7.8 46.0 297 29 15 6.8 3.7 | 5.9 42.6 317 14 7 7.2 4.0
8250 8.3 46.9 298 28 14 6.9 3.8 | 6.4 43.5 321 13 7 6.9 3.8
8000 8.8 47.8 299 27 14 7.0 3.8 | 6.9 44.4 327 12 6 6.5 3.5
7750 9.3 48.7 300 25 13 6.9 3.8 | 7.4 45.3 334 11 6 6.5 3.6
7500 9.8 49.6 302 23 12 7.3 4.0 | 7.9 46.2 343 10 5 6.5 3.6
7250 10.3 50.5 304 22 11 5.7 3.1 | 8.3 46.9 352 9 5 6.5 3.6
7000 10.7 51.3 307 19 10 4.0 2.2 | 8.8 47.8 001 8 4 6.6 3.6
6750 11.0 51.8 310 17 9 4.9 2.7 | 9.3 48.7 012 7 4 6.4 3.5
6500 11.3 52.3 315 14 7 2.9 1.6 | 9.8 49.6 025 7 3 7.5 4.1
6250 11.3 52.3 317 11 6 -2.9 -1.6 | 10.4 50.7 031 6 3 9.2 5.0
6000 10.9 51.6 312 8 4 -5.9 -3.2 | 11.1 52.0 033 6 3 8.9 4.9
5750 10.5 50.9 298 4 2 -3.8 -2.1 | 11.7 53.1 035 5 3 10.2 5.6
5500 10.1 50.2 229 2 1 -11.2 -6.2 | 12.6 54.7 035 5 3 15.8 8.7
11/08/2009 AT 1400 MST | 11/08/2009 AT 1700 MST
|
K INDEX... +0.3 | K INDEX... +15.4
|
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 -62.6 -80.7 233 52 27 0.2 0.1 | -62.2 -80.0 236 51 26 0.4 0.2
45000 -62.2 -80.0 227 64 33 0.5 0.3 | -61.6 -78.9 233 61 31 0.5 0.3
40000 -61.4 -78.5 238 67 35 0.5 0.3 | -60.2 -76.4 241 67 35 0.9 0.5
38000 -58.9 -74.0 238 68 35 6.7 3.7 | -58.2 -72.8 241 69 36 5.2 2.8
36000 -54.8 -66.6 234 69 35 6.7 3.7 | -55.1 -67.2 240 70 36 5.2 2.8
34000 -50.8 -59.4 233 68 35 6.5 3.6 | -51.8 -61.2 240 68 35 6.4 3.5
32000 -47.0 -52.6 239 62 32 6.5 3.6 | -47.9 -54.2 244 61 31 6.4 3.5
30000 -42.4 -44.3 245 57 29 7.6 4.1 | -43.3 -45.9 250 53 27 8.0 4.4
29000 -40.1 -40.2 247 53 27 7.6 4.1 | -40.9 -41.6 251 50 26 8.0 4.4
28000 -37.8 -36.0 249 50 26 7.5 4.1 | -38.5 -37.3 252 48 24 8.0 4.4
27000 -35.5 -31.9 251 47 24 8.4 4.6 | -36.1 -33.0 254 45 23 8.4 4.6
26000 -33.0 -27.4 251 44 23 8.3 4.6 | -33.6 -28.5 255 43 22 8.4 4.6
25000 -30.5 -22.9 251 42 21 8.3 4.6 | -31.1 -24.0 255 41 21 8.4 4.6
24000 -28.0 -18.4 251 39 20 8.1 4.4 | -28.6 -19.5 256 39 20 7.5 4.1
23000 -25.7 -14.3 248 37 19 7.9 4.4 | -26.5 -15.7 256 34 18 7.0 3.9
22000 -23.3 -9.9 245 36 19 7.9 4.4 | -24.4 -11.9 255 30 15 7.0 3.8
21000 -20.9 -5.6 242 35 18 7.9 4.4 | -22.2 -8.0 254 26 13 8.1 4.5
20000 -18.5 -1.3 243 33 17 7.9 4.4 | -19.8 -3.6 253 26 14 8.1 4.4
19500 -17.3 0.9 243 32 17 7.9 4.4 | -18.6 -1.5 253 26 14 8.1 4.4
19000 -16.1 3.0 243 32 16 7.9 4.3 | -17.4 0.7 253 26 14 8.1 4.5
18500 -14.9 5.2 244 31 16 8.3 4.5 | -16.2 2.8 253 26 14 7.2 3.9
18000 -13.7 7.3 245 30 15 8.4 4.6 | -15.2 4.6 254 26 14 7.0 3.8
17500 -12.4 9.7 247 29 15 8.1 4.5 | -14.1 6.6 256 26 13 6.8 3.7
17000 -11.3 11.7 248 28 14 6.9 3.8 | -13.2 8.2 255 26 13 5.9 3.2
16500 -9.8 14.4 248 26 13 6.3 3.4 | -11.9 10.6 254 26 13 6.0 3.3
16000 -9.0 15.8 247 25 13 4.7 2.6 | -11.1 12.0 252 25 13 6.1 3.3
15500 -8.4 16.9 247 24 12 4.8 2.7 | -10.2 13.6 250 24 12 6.3 3.4
15000 -7.7 18.1 247 23 12 4.0 2.2 | -9.2 15.4 249 22 12 8.2 4.5
14500 -7.2 19.0 248 21 11 4.0 2.2 | -8.1 17.4 250 20 11 8.1 4.4
14000 -6.4 20.5 249 20 10 7.0 3.8 | -6.9 19.6 251 18 10 7.8 4.3
13500 -5.4 22.3 252 18 10 7.2 3.9 | -5.8 21.6 253 16 8 7.9 4.3
13000 -4.4 24.1 256 17 9 7.4 4.1 | -4.7 23.5 255 14 7 6.9 3.8
12500 -3.3 26.1 262 16 8 7.5 4.1 | -3.7 25.3 257 12 6 6.8 3.7
12000 -2.2 28.0 269 14 7 7.6 4.1 | -2.8 27.0 258 9 5 5.7 3.1
11500 -1.0 30.2 274 12 6 7.6 4.2 | -2.0 28.4 251 5 3 5.4 2.9
11000 0.1 32.2 282 10 5 7.0 3.8 | -1.0 30.2 223 2 1 7.6 4.2
10500 1.0 33.8 292 6 3 6.8 3.7 | 0.2 32.4 134 2 1 8.2 4.5
10250 1.5 34.7 304 4 2 6.8 3.7 | 0.8 33.4 116 4 2 8.5 4.7
10000 2.0 35.6 324 3 2 7.3 4.0 | 1.5 34.7 110 5 2 9.3 5.1
9750 2.6 36.7 002 2 1 7.5 4.1 | 2.2 36.0 107 5 3 9.5 5.2
9500 3.1 37.6 054 2 1 7.3 4.0 | 2.9 37.2 105 6 3 9.4 5.2
9250 3.6 38.5 077 4 2 8.0 4.4 | 3.6 38.5 103 7 4 9.5 5.2
9000 4.3 39.7 083 5 2 9.3 5.1 | 4.3 39.7 102 8 4 9.6 5.3
8750 5.0 41.0 085 5 3 9.7 5.3 | 5.0 41.0 102 8 4 9.7 5.3
8500 5.7 42.3 087 5 3 9.5 5.2 | 5.8 42.4 101 9 4 9.7 5.3
8250 6.4 43.5 089 5 3 9.7 5.3 | 6.5 43.7 101 9 5 9.5 5.2
8000 7.1 44.8 089 5 3 9.8 5.4 | 7.2 45.0 101 10 5 9.4 5.2
7750 7.9 46.2 089 5 3 9.8 5.4 | 7.9 46.2 101 10 5 9.5 5.2
7500 8.6 47.5 089 5 3 9.8 5.4 | 8.6 47.5 101 11 5 9.5 5.2
7250 9.3 48.7 089 5 3 9.6 5.3 | 9.3 48.7 101 11 6 9.5 5.2
7000 10.0 50.0 090 5 3 9.6 5.3 | 10.0 50.0 101 11 6 9.5 5.2
6750 10.7 51.3 090 5 3 9.5 5.2 | 10.7 51.3 101 12 6 9.5 5.2
6500 11.5 52.7 090 5 3 9.9 5.4 | 11.4 52.5 101 12 6 9.5 5.2
6250 12.2 54.0 091 5 3 10.5 5.7 | 12.1 53.8 101 12 6 9.1 5.0
6000 13.0 55.4 091 5 3 10.2 5.6 | 12.8 55.0 102 12 6 10.3 5.6
5750 13.8 56.8 092 5 2 11.2 6.2 | 13.5 56.3 103 12 6 6.0 3.3
5500 14.7 58.5 090 5 3 15.8 8.7 | 13.4 56.1 104 9 5 -8.0 -4.4
________________________________________________________________________________
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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