National Weather Service Text Product
AFOS product SRGBOU
Dates interpreted at 00:00 UTCDisplaying AFOS PIL: SRGBOU
Product Timestamp: 2016-01-22 01:00 UTC
Bulk Download
Bulk Download Help
This bulk download tool provides the NWS text
in a raw form, hopefully directly usable by your processing system.
You can either provide a complete 6-character PIL/AFOS ID or provide
the 3-character base ID (e.g., AFD). The start and end
dates represent 00 UTC for those dates. The Zip format is useful as
the filenames will have the product timestamp, which is useful for
when the product format has ambiguous timestamps.
024
UXUS97 KBOU 220100
SRGBOU
Soaring Forecast
National Weather Service Denver/Boulder, Colorado
1759 MST Thursday, January 21, 2016
This forecast is for Friday, January 22, 2016:
If the trigger temperature of 51.5 F/10.8 C is reached...then
Thermal Soaring Index....................... Fair
Maximum rate of lift........................ 352 ft/min (1.8 m/s)
Maximum height of thermals.................. 10385 ft MSL (5078 ft AGL)
Forecast maximum temperature................... 55.0 F/13.2 C
Time of trigger temperature.................... 1245 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................. 8677 ft MSL (3370 ft AGL)
Thermal soaring outlook for Saturday 01/23..... Fair
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)................ Neither
Potential height of wave....................... 15151 ft MSL (9844 ft AGL)
Wave soaring outlook for Saturday 01/23........ Poor
Remarks... None
Sunrise/Sunset.................... 07:15:20 / 17:05:42 MST
Total possible sunshine........... 9 hr 50 min 22 sec (590 min 22 sec)
Altitude of sun at 12:10:55 MST... 30.62 degrees
Upper air data from numerical model forecast valid on 01/22/2016 at 0500 MST
Freezing level.................. 5778 ft MSL (471 ft AGL)
Additional freezing level....... 8374 ft MSL (3067 ft AGL)
Convective condensation level... 18462 ft MSL (13155 ft AGL)
Lifted condensation level....... 14428 ft MSL (9121 ft AGL)
Lifted index.................... +7.3
K index......................... +5.9
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 -60.2 -76.4 310 36 19 0.2 0.1 M M M M M
45000 -59.9 -75.8 315 45 23 -0.0 -0.0 M M M M M
40000 -65.2 -85.4 325 37 19 -3.7 -2.0 M M M M M
38000 -64.1 -83.4 325 36 19 7.6 4.2 M M M M M
36000 -59.5 -75.1 325 39 20 7.6 4.2 M M M M M
34000 -54.9 -66.8 320 42 21 8.2 4.5 M M M M M
32000 -49.3 -56.7 315 39 20 8.2 4.5 M M M M M
30000 -44.5 -48.1 315 35 18 8.0 4.4 31.2 88.2 13.8 M M
29000 -42.1 -43.8 315 31 16 8.0 4.4 30.5 86.8 13.4 M M
28000 -39.7 -39.5 315 27 14 8.0 4.4 29.8 85.7 13.1 M M
27000 -37.3 -35.1 315 24 12 7.8 4.3 29.3 84.7 12.8 M M
26000 -34.9 -30.8 315 23 12 7.8 4.3 28.4 83.1 12.3 M M
25000 -32.6 -26.7 315 23 12 7.8 4.3 27.7 81.8 11.9 M M
24000 -30.3 -22.5 320 22 11 8.3 4.5 27.1 80.7 11.5 M M
23000 -27.7 -17.9 320 23 12 8.5 4.7 26.5 79.7 11.2 M M
22000 -25.2 -13.4 320 24 13 8.5 4.7 26.1 79.0 11.0 M M
21000 -22.7 -8.9 320 25 13 8.1 4.4 25.7 78.2 10.7 M M
20000 -20.2 -4.4 320 26 14 8.1 4.5 25.0 77.1 10.3 M M
19500 -19.0 -2.2 320 27 14 8.1 4.5 24.8 76.6 10.1 M M
19000 -17.8 -0.0 320 27 14 8.2 4.5 24.5 76.1 10.0 M M
18500 -16.6 2.1 320 27 14 7.8 4.3 24.3 75.7 9.8 M M
18000 -15.4 4.3 320 27 14 7.8 4.3 23.9 75.0 9.5 M M
17500 -14.3 6.3 325 27 14 7.6 4.1 23.6 74.4 9.3 M M
17000 -13.2 8.2 330 27 14 6.8 3.7 23.1 73.6 8.9 M M
16500 -11.7 10.9 335 27 14 7.2 3.9 22.4 72.3 8.3 M M
16000 -10.6 12.9 335 28 14 7.6 4.2 22.0 71.6 8.0 M M
15500 -9.5 14.9 340 28 15 7.5 4.1 21.6 71.0 7.7 M M
15000 -8.6 16.5 340 29 15 5.1 2.8 21.0 69.8 7.2 M M
14500 -7.8 18.0 340 29 15 5.4 3.0 20.3 68.5 6.5 M M
14000 -7.1 19.2 340 29 15 4.4 2.4 19.5 67.1 5.8 M M
13500 -6.4 20.5 340 28 15 4.5 2.5 18.6 65.5 5.0 M M
13000 -5.8 21.6 340 27 14 4.5 2.4 17.8 64.0 4.3 M M
12500 -5.1 22.8 340 26 14 4.5 2.4 16.9 62.4 3.5 M M
12000 -4.5 23.9 340 26 13 4.5 2.5 16.1 60.9 2.7 M M
11500 -3.8 25.2 335 25 13 4.6 2.5 15.2 59.4 1.9 M M
11000 -3.2 26.2 335 24 12 3.9 2.1 14.4 57.8 1.1 M M
10500 -2.6 27.3 335 22 12 4.1 2.3 13.4 56.1 0.2 M M
10250 -2.4 27.7 335 22 11 2.3 1.3 12.9 55.3 -0.3 342 1.7
10000 -2.2 28.0 340 21 11 2.3 1.3 12.3 54.1 -0.9 331 1.7
9750 -1.9 28.6 340 20 10 5.1 2.8 11.8 53.3 -1.3 314 1.6
9500 -1.5 29.3 340 18 9 5.9 3.2 11.5 52.7 -1.6 294 1.5
9250 -1.1 30.0 340 16 8 4.2 2.3 11.2 52.1 -1.9 274 1.4
9000 -0.9 30.4 335 14 7 2.8 1.5 10.6 51.2 -2.4 260 1.3
8750 -0.6 30.9 330 13 6 4.6 2.6 10.2 50.3 -2.9 244 1.2
8500 -0.2 31.6 325 11 6 5.0 2.7 9.8 49.7 -3.2 224 1.1
8250 0.1 32.2 315 10 5 3.2 1.8 9.4 48.9 -3.7 208 1.1
8000 0.3 32.5 305 9 5 2.6 1.4 8.8 47.9 -4.2 194 1.0
7750 0.5 32.9 295 8 4 2.6 1.4 8.3 46.9 -4.7 181 0.9
7500 0.8 33.4 285 8 4 4.3 2.4 7.8 46.0 -5.3 167 0.8
7250 1.2 34.2 285 8 4 5.9 3.2 7.4 45.4 -5.6 147 0.7
7000 1.6 34.9 290 8 4 5.9 3.2 7.1 44.8 -5.9 127 0.6
6750 2.0 35.6 290 8 4 5.0 2.7 6.8 44.3 -6.2 107 0.5
6500 2.2 36.0 290 9 4 -1.2 -0.7 6.3 43.3 -6.8 94 0.5
6250 2.0 35.6 290 10 5 -2.6 -1.5 5.3 41.5 -7.8 94 0.5
6000 1.7 35.1 290 11 6 -8.0 -4.4 4.3 39.7 -8.8 94 0.5
5750 0.3 32.5 280 11 6 -32.7 -17.9 2.1 35.8 -11.0 130 0.7
5500 -3.1 26.4 255 7 3 -52.7 -28.9 -2.0 28.5 -15.1 223 1.1
* * * * * * Numerical weather prediction model forecast data valid * * * * * *
01/22/2016 at 0800 MST | 01/22/2016 at 1100 MST
|
K index... +8.7 LI... +4.5 | K index... +8.8 LI... +4.1
CAPE... 0.0 CIN... 0.0 | CAPE... 0.0 CIN... -0.1
|
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 -59.7 -75.5 310 37 19 -0.1 -0.1 | -59.7 -75.5 310 34 17 0.3 0.1
45000 -59.9 -75.8 315 43 22 -0.4 -0.2 | -59.3 -74.7 315 38 20 -0.0 -0.0
40000 -65.2 -85.4 315 31 16 -3.6 -2.0 | -64.5 -84.1 310 35 18 -3.6 -2.0
38000 -64.1 -83.4 320 30 15 7.6 4.2 | -63.6 -82.5 310 34 17 7.0 3.9
36000 -59.5 -75.1 320 32 16 7.6 4.2 | -59.4 -74.9 315 32 16 7.0 3.9
34000 -54.9 -66.8 325 34 17 8.3 4.5 | -54.4 -65.9 320 31 16 8.2 4.5
32000 -49.3 -56.7 320 34 18 8.2 4.5 | -49.4 -56.9 320 31 16 8.3 4.5
30000 -44.3 -47.7 320 34 17 8.2 4.5 | -44.5 -48.1 320 31 16 8.1 4.5
29000 -41.9 -43.4 320 32 17 8.2 4.5 | -42.1 -43.8 325 31 16 8.1 4.5
28000 -39.4 -38.9 315 31 16 8.2 4.5 | -39.6 -39.3 325 30 16 8.1 4.5
27000 -37.0 -34.6 315 30 15 8.0 4.4 | -37.2 -35.0 330 30 16 8.3 4.6
26000 -34.6 -30.3 315 27 14 8.0 4.4 | -34.7 -30.5 325 29 15 8.3 4.6
25000 -32.2 -26.0 315 24 13 8.0 4.4 | -32.2 -26.0 325 28 14 8.3 4.6
24000 -29.8 -21.6 310 22 11 8.0 4.4 | -29.7 -21.5 325 27 14 8.1 4.4
23000 -27.4 -17.3 315 21 11 7.9 4.4 | -27.3 -17.1 320 25 13 7.9 4.4
22000 -25.0 -13.0 315 20 10 8.0 4.4 | -24.9 -12.8 320 22 11 8.0 4.4
21000 -22.7 -8.9 320 19 10 7.8 4.3 | -22.6 -8.7 320 20 10 7.9 4.3
20000 -20.3 -4.5 320 18 9 7.8 4.3 | -20.2 -4.4 325 18 9 7.9 4.3
19500 -19.2 -2.6 320 18 9 7.8 4.3 | -19.0 -2.2 325 17 9 7.9 4.3
19000 -18.0 -0.4 320 17 9 7.8 4.3 | -17.8 -0.0 325 16 8 7.9 4.4
18500 -16.8 1.8 320 17 9 7.6 4.2 | -16.7 1.9 325 15 8 7.3 4.0
18000 -15.7 3.7 320 16 8 7.6 4.1 | -15.1 4.8 320 14 7 7.2 3.9
17500 -14.6 5.7 325 15 8 7.4 4.1 | -14.0 6.8 315 13 7 7.1 3.9
17000 -13.5 7.7 325 15 8 7.0 3.9 | -13.0 8.6 315 11 6 7.1 3.9
16500 -12.0 10.4 335 15 8 6.7 3.7 | -11.9 10.6 315 10 5 7.0 3.8
16000 -11.0 12.2 335 16 8 6.4 3.5 | -10.9 12.4 320 11 6 6.9 3.8
15500 -10.1 13.8 340 18 9 6.4 3.5 | -9.9 14.2 325 11 6 6.9 3.8
15000 -9.2 15.4 340 19 10 6.4 3.5 | -8.9 16.0 330 12 6 6.9 3.8
14500 -8.2 17.2 340 20 10 6.4 3.5 | -7.9 17.8 330 13 6 6.9 3.8
14000 -7.3 18.9 340 21 11 6.1 3.4 | -6.9 19.6 330 13 7 6.5 3.6
13500 -6.4 20.5 340 21 11 6.1 3.4 | -5.9 21.4 330 14 7 6.6 3.6
13000 -5.5 22.1 340 22 11 6.4 3.5 | -4.9 23.2 330 14 7 6.9 3.8
12500 -4.5 23.9 340 22 11 6.4 3.5 | -3.9 25.0 330 14 7 6.9 3.8
12000 -3.6 25.5 335 22 11 5.9 3.2 | -2.9 26.8 330 15 7 6.7 3.7
11500 -2.8 27.0 335 22 11 5.9 3.2 | -1.9 28.6 330 15 7 6.8 3.7
11000 -2.0 28.4 335 21 11 4.8 2.6 | -1.0 30.2 325 14 7 5.6 3.1
10500 -1.3 29.7 335 20 10 5.3 2.9 | -0.2 31.6 325 13 7 6.0 3.3
10250 -0.9 30.4 335 19 10 2.4 1.3 | 0.2 32.4 325 13 7 3.2 1.7
10000 -0.9 30.4 335 19 10 1.8 1.0 | 0.4 32.7 325 13 7 3.4 1.9
9750 -0.6 30.9 335 17 9 5.0 2.8 | 0.8 33.4 320 12 6 6.8 3.7
9500 -0.2 31.6 335 16 8 5.3 2.9 | 1.3 34.3 320 11 6 6.8 3.7
9250 0.2 32.4 340 14 7 4.3 2.4 | 1.8 35.2 315 10 5 4.8 2.6
9000 0.5 32.9 335 13 7 3.6 2.0 | 2.0 35.6 310 9 5 3.2 1.8
8750 0.8 33.4 335 12 6 5.0 2.7 | 2.3 36.1 310 9 4 4.9 2.7
8500 1.2 34.2 330 10 5 5.1 2.8 | 2.7 36.9 300 8 4 5.1 2.8
8250 1.5 34.7 325 8 4 3.5 1.9 | 3.1 37.6 295 7 4 4.1 2.2
8000 1.7 35.1 320 8 4 2.7 1.5 | 3.3 37.9 290 7 3 3.7 2.0
7750 2.0 35.6 310 7 4 3.8 2.1 | 3.6 38.5 280 6 3 3.6 2.0
7500 2.3 36.1 305 7 3 3.9 2.2 | 3.9 39.0 270 6 3 3.4 1.9
7250 2.5 36.5 300 7 3 3.2 1.7 | 4.1 39.4 270 6 3 3.3 1.8
7000 2.8 37.0 300 7 3 3.4 1.9 | 4.4 39.9 270 6 3 3.6 2.0
6750 3.0 37.4 300 7 3 3.1 1.7 | 4.6 40.3 270 6 3 2.3 1.2
6500 3.1 37.6 300 7 3 -1.8 -1.0 | 4.7 40.5 265 6 3 -0.6 -0.4
6250 2.8 37.0 295 8 4 -3.3 -1.8 | 4.6 40.3 260 6 3 -0.0 -0.0
6000 2.6 36.7 290 9 4 -7.7 -4.2 | 4.6 40.3 250 6 3 -3.9 -2.2
5750 1.1 34.0 275 9 4 -34.6 -19.0 | 3.7 38.7 240 6 3 -20.1 -11.0
5500 -2.6 27.3 245 6 3 -60.8 -33.4 | 1.5 34.7 220 5 2 -33.1 -18.2
01/22/2016 at 1400 MST | 01/22/2016 at 1700 MST
|
K index... +6.2 LI... +4.7 | K index... +2.9 LI... +4.8
CAPE... 0.0 CIN... -0.2 | CAPE... 0.0 CIN... -0.2
|
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 -59.7 -75.5 310 29 15 0.5 0.3 | -60.4 -76.7 300 30 16 0.5 0.3
45000 -58.9 -74.0 305 35 18 0.2 0.1 | -59.7 -75.5 310 35 18 0.2 0.1
40000 -64.1 -83.4 305 38 20 -3.6 -2.0 | -63.4 -82.1 305 42 22 -2.6 -1.4
38000 -63.4 -82.1 305 37 19 7.0 3.8 | -62.5 -80.5 305 42 22 6.0 3.3
36000 -58.6 -73.5 310 34 17 7.0 3.8 | -58.9 -74.0 305 39 20 6.0 3.3
34000 -54.3 -65.7 315 32 16 8.0 4.4 | -54.4 -65.9 310 36 19 8.2 4.5
32000 -49.5 -57.1 315 32 16 8.0 4.4 | -49.5 -57.1 310 36 19 8.2 4.5
30000 -44.7 -48.5 310 31 16 7.8 4.3 | -44.5 -48.1 310 36 18 8.3 4.6
29000 -42.4 -44.3 310 31 16 7.8 4.3 | -42.0 -43.6 305 35 18 8.3 4.6
28000 -40.0 -40.0 310 30 15 7.8 4.3 | -39.5 -39.1 305 34 17 8.3 4.6
27000 -37.6 -35.7 310 29 15 8.5 4.6 | -37.0 -34.6 305 32 17 8.6 4.7
26000 -35.1 -31.2 315 29 15 8.6 4.7 | -34.5 -30.1 305 31 16 8.6 4.7
25000 -32.5 -26.5 315 29 15 8.6 4.7 | -31.9 -25.4 305 29 15 8.6 4.7
24000 -30.0 -22.0 315 29 15 8.6 4.7 | -29.3 -20.7 305 28 14 8.2 4.5
23000 -27.4 -17.3 315 27 14 8.6 4.7 | -26.9 -16.4 305 25 13 8.0 4.4
22000 -24.8 -12.6 320 25 13 8.6 4.7 | -24.5 -12.1 300 22 11 8.0 4.4
21000 -22.2 -8.0 320 23 12 8.2 4.5 | -22.1 -7.8 300 20 10 8.0 4.4
20000 -19.8 -3.6 320 22 11 8.2 4.5 | -19.7 -3.5 305 20 10 8.0 4.4
19500 -18.5 -1.3 320 21 11 8.2 4.5 | -18.5 -1.3 305 20 10 8.0 4.4
19000 -17.3 0.9 320 20 10 8.3 4.5 | -17.3 0.9 305 19 10 8.0 4.4
18500 -16.1 3.0 315 20 10 7.4 4.1 | -16.1 3.0 305 19 10 7.8 4.3
18000 -14.5 5.9 315 19 10 7.2 3.9 | -14.9 5.2 310 19 10 7.8 4.3
17500 -13.4 7.9 315 19 10 7.1 3.9 | -13.2 8.2 310 19 10 8.1 4.4
17000 -12.4 9.7 315 19 10 7.1 3.9 | -12.0 10.4 310 20 10 8.1 4.5
16500 -11.3 11.7 310 19 10 7.0 3.8 | -10.8 12.6 310 20 10 8.0 4.4
16000 -10.3 13.5 310 17 9 6.8 3.7 | -9.6 14.7 310 20 10 7.7 4.2
15500 -9.3 15.3 305 16 8 6.8 3.7 | -8.5 16.7 310 19 10 7.7 4.2
15000 -8.3 17.1 305 14 7 6.9 3.8 | -7.4 18.7 310 19 10 6.7 3.7
14500 -7.3 18.9 305 14 7 6.9 3.8 | -6.4 20.5 310 18 9 6.9 3.8
14000 -6.3 20.7 300 13 7 6.7 3.7 | -5.4 22.3 310 18 9 6.0 3.3
13500 -5.3 22.5 300 12 6 6.8 3.7 | -4.6 23.7 305 17 9 6.0 3.3
13000 -4.4 24.1 300 11 6 6.3 3.4 | -3.7 25.3 305 17 9 5.9 3.2
12500 -3.4 25.9 300 11 6 6.2 3.4 | -2.8 27.0 300 16 8 5.8 3.2
12000 -2.5 27.5 295 10 5 6.1 3.3 | -1.9 28.6 300 15 8 6.2 3.4
11500 -1.6 29.1 295 10 5 6.1 3.3 | -1.0 30.2 295 14 7 6.3 3.4
11000 -0.7 30.7 295 9 5 5.9 3.2 | -0.1 31.8 295 13 7 6.8 3.7
10500 0.1 32.2 290 8 4 6.4 3.5 | 1.0 33.8 295 13 6 7.8 4.3
10250 0.6 33.1 290 8 4 3.4 1.9 | 1.5 34.7 295 12 6 3.3 1.8
10000 0.7 33.3 290 8 4 4.6 2.5 | 1.6 34.9 290 12 6 4.1 2.2
9750 1.3 34.3 290 8 4 8.3 4.6 | 2.2 36.0 290 12 6 9.0 4.9
9500 1.9 35.4 290 7 4 7.6 4.2 | 2.8 37.0 290 11 6 8.2 4.5
9250 2.4 36.3 285 7 4 6.6 3.6 | 3.3 37.9 290 11 6 6.6 3.6
9000 2.8 37.0 285 7 4 5.6 3.1 | 3.7 38.7 290 11 6 4.5 2.5
8750 3.3 37.9 285 7 4 6.9 3.8 | 4.1 39.4 290 11 6 5.4 3.0
8500 3.8 38.8 285 7 4 7.2 3.9 | 4.5 40.1 290 10 5 5.8 3.2
8250 4.3 39.7 290 7 4 6.1 3.3 | 4.9 40.8 290 10 5 4.7 2.6
8000 4.7 40.5 290 8 4 5.2 2.9 | 5.1 41.2 285 9 4 3.8 2.1
7750 5.1 41.2 290 8 4 5.1 2.8 | 5.4 41.7 280 8 4 3.7 2.0
7500 5.5 41.9 295 8 4 3.7 2.1 | 5.7 42.3 275 7 3 3.7 2.0
7250 5.7 42.3 295 7 3 2.2 1.2 | 6.0 42.8 265 6 3 4.4 2.4
7000 5.8 42.4 290 5 3 2.0 1.1 | 6.3 43.3 250 5 3 4.5 2.5
6750 5.9 42.6 285 4 2 1.6 0.9 | 6.7 44.1 230 4 2 4.7 2.6
6500 6.0 42.8 255 3 1 0.0 0.0 | 7.0 44.6 215 5 2 2.2 1.2
6250 5.9 42.6 220 3 2 -1.3 -0.7 | 7.0 44.6 210 4 2 -0.7 -0.4
6000 5.9 42.6 195 4 2 0.7 0.4 | 7.0 44.6 200 4 2 2.5 1.4
5750 5.8 42.4 180 6 3 -5.8 -3.2 | 7.0 44.6 195 4 2 -7.5 -4.1
5500 4.6 40.3 175 5 3 -26.7 -14.6 | 5.2 41.4 190 4 2 -41.5 -22.8
________________________________________________________________________________
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.
CIN (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