278
UXUS97 KPUB 191303
SRGPUB
SOARING FORECAST
NATIONAL WEATHER SERVICE PUEBLO, COLORADO
0603 MST TUESDAY, NOVEMBER 19, 2024
THIS FORECAST IS FOR VILLA GROVE, CO FOR TUESDAY, NOVEMBER 19, 2024:
IF THE TRIGGER TEMPERATURE OF 29.7 F/-1.3 C IS REACHED...THEN
THERMAL SOARING INDEX....................... POOR
MAXIMUM RATE OF LIFT........................ 83 FT/MIN (0.4 M/S)
MAXIMUM HEIGHT OF THERMALS.................. 13826 FT MSL (4811 FT AGL)
FORECAST MAXIMUM TEMPERATURE................... 30.0 F/-1.6 C
TIME OF TRIGGER TEMPERATURE.................... 1100 MST
TIME OF OVERDEVELOPMENT........................ NONE
MIDDLE/HIGH CLOUDS DURING SOARING WINDOW....... BROKEN/OVERCAST OPAQUE MIDDLE
SURFACE WINDS DURING SOARING WINDOW............ BETWEEN 20 MPH AND 30 MPH
HEIGHT OF THE -3 THERMAL INDEX................. 10082 FT MSL (1067 FT AGL)
THERMAL SOARING OUTLOOK FOR WEDNESDAY 11/20.... FAIR
WAVE SOARING INDEX............................. NOT AVAILABLE
REMARKS...
SUNRISE/SUNSET.................... 06:50:04 / 16:48:10 MST
TOTAL POSSIBLE SUNSHINE........... 9 HR 58 MIN 6 SEC (598 MIN 6 SEC)
ALTITUDE OF SUN AT 11:49:07 MST... 31.97 DEGREES
UPPER AIR DATA FROM NUMERICAL MODEL FORECAST VALID ON 11/19/2024 AT 0500 MST
FREEZING LEVEL.................. ENTIRE AIRMASS BELOW 32 F / 0 C
CONVECTIVE CONDENSATION LEVEL... 14789 FT MSL (5774 FT AGL)
LIFTED CONDENSATION LEVEL....... 14589 FT MSL (5574 FT AGL)
LIFTED INDEX.................... +10.3
K INDEX......................... -0.0
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 -56.5 -69.7 230 67 34 3.2 1.8 M M M M M
45000 -51.4 -60.5 230 82 42 3.4 1.8 M M M M M
40000 -45.9 -50.6 245 78 40 3.7 2.0 M M M M M
38000 -44.2 -47.6 250 76 39 0.8 0.4 M M M M M
36000 -43.8 -46.8 245 71 37 0.7 0.4 M M M M M
34000 -43.4 -46.1 240 66 34 0.7 0.4 M M M M M
32000 -42.8 -45.0 245 66 34 1.1 0.6 M M M M M
30000 -42.0 -43.6 255 68 35 1.0 0.5 M M M M M
29000 -41.5 -42.7 255 68 35 1.9 1.0 21.3 70.4 17.7 M M
28000 -41.0 -41.8 255 67 35 1.9 1.0 18.3 64.9 15.5 M M
27000 -40.4 -40.7 255 67 34 1.9 1.0 15.4 59.8 13.4 M M
26000 -39.9 -39.8 255 66 34 1.3 0.7 12.6 54.7 11.2 M M
25000 -39.5 -39.1 255 64 33 1.4 0.7 9.4 48.9 8.7 M M
24000 -39.1 -38.4 255 62 32 1.3 0.7 6.4 43.6 6.3 M M
23000 -38.3 -36.9 250 61 31 7.9 4.3 4.0 39.2 4.3 M M
22000 -35.9 -32.6 250 59 30 7.8 4.3 3.2 37.8 3.7 M M
21000 -33.6 -28.5 250 57 29 7.9 4.3 2.6 36.7 3.2 M M
20000 -31.2 -24.2 250 53 27 8.2 4.5 2.0 35.6 2.7 M M
19500 -30.0 -22.0 250 51 26 8.2 4.5 1.7 35.1 2.4 M M
19000 -28.8 -19.8 250 48 25 8.2 4.5 1.5 34.6 2.2 M M
18500 -27.6 -17.7 250 46 24 8.2 4.5 1.2 34.2 2.0 M M
18000 -26.4 -15.5 250 43 22 8.5 4.6 1.0 33.8 1.8 M M
17500 -25.0 -13.0 250 42 22 8.8 4.9 0.8 33.5 1.7 M M
17000 -23.1 -9.6 250 41 21 8.8 4.8 0.6 33.1 1.5 M M
16500 -21.8 -7.2 250 38 19 8.7 4.8 0.4 32.8 1.3 M M
16000 -20.5 -4.9 255 34 18 8.5 4.7 0.3 32.5 1.2 M M
15500 -19.3 -2.7 255 34 17 7.8 4.3 0.0 32.0 0.9 M M
15000 -18.1 -0.6 260 35 18 7.8 4.3 -0.3 31.5 0.6 M M
14500 -16.8 1.8 265 37 19 8.7 4.8 -0.5 31.1 0.4 M M
14000 -15.7 3.7 265 38 20 6.6 3.6 -0.9 30.5 0.1 M M
13500 -14.5 5.9 270 39 20 10.4 5.7 -1.1 30.1 -0.1 441 2.2
13000 -13.0 8.6 270 39 20 7.0 3.8 -1.1 30.0 -0.2 383 1.9
12500 -12.0 10.4 270 39 20 9.4 5.2 -1.5 29.3 -0.6 337 1.7
12000 -10.6 12.9 270 38 19 8.5 4.7 -1.5 29.2 -0.6 280 1.4
11750 -10.1 13.8 270 37 19 6.5 3.6 -1.7 28.9 -0.8 257 1.3
11500 -9.6 14.7 270 35 18 7.4 4.1 -2.0 28.5 -1.1 235 1.2
11250 -9.0 15.8 270 33 17 7.9 4.4 -2.1 28.2 -1.2 210 1.1
11000 -8.4 16.9 270 30 15 8.6 4.7 -2.2 28.0 -1.4 185 0.9
10750 -7.8 18.0 270 27 14 5.5 3.0 -2.4 27.7 -1.5 160 0.8
10500 -7.6 18.3 270 27 14 2.1 1.2 -2.9 26.8 -2.1 147 0.7
10250 -7.4 18.7 270 25 13 2.8 1.5 -3.4 25.8 -2.6 134 0.7
10000 -7.3 18.9 270 24 12 2.5 1.4 -4.0 24.8 -3.2 121 0.6
9750 -7.1 19.2 270 23 12 3.2 1.8 -4.5 23.9 -3.7 108 0.5
9500 -6.8 19.8 265 19 10 2.0 1.1 -5.0 23.0 -4.3 94 0.5
9250 -6.9 19.6 265 13 7 -2.2 -1.2 -5.7 21.7 -5.0 87 0.4
9000 M M M M M M M M M M M M
8750 M M M M M M M M M M M M
8500 M M M M M M M M M M M M
8250 M M M M M M M M M M M M
8000 M M M M M M M M M M M M
* * * * * * NUMERICAL WEATHER PREDICTION MODEL FORECAST DATA VALID * * * * * *
11/19/2024 AT 0800 MST | 11/19/2024 AT 1100 MST
|
CAPE... 0.0 LI... -0.8 | CAPE... +9.7 LI... +2.0
CINH... 0.0 K INDEX... +4.8 | CINH... -4.2 K INDEX... -31.3
|
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 -56.2 -69.2 230 68 35 3.3 1.8 | -54.9 -66.8 230 57 29 0.8 0.4
45000 -51.3 -60.3 230 78 40 3.3 1.8 | -53.7 -64.7 235 69 36 0.7 0.4
40000 -46.2 -51.2 240 83 43 3.2 1.8 | -48.8 -55.8 245 65 34 3.4 1.9
38000 -44.7 -48.5 245 82 42 1.0 0.6 | -47.0 -52.6 250 64 33 1.4 0.8
36000 -44.1 -47.4 250 71 37 0.9 0.5 | -46.0 -50.8 260 67 35 1.5 0.8
34000 -43.5 -46.3 260 62 32 0.9 0.5 | -45.1 -49.2 270 72 37 1.5 0.8
32000 -43.5 -46.3 260 66 34 -0.2 -0.1 | -44.4 -47.9 270 77 40 1.1 0.6
30000 -43.6 -46.5 260 75 38 -0.1 -0.1 | -43.7 -46.7 270 82 42 1.0 0.6
29000 -43.3 -45.9 260 75 39 1.9 1.0 | -43.0 -45.4 270 82 42 3.1 1.7
28000 -42.7 -44.9 255 72 37 1.9 1.0 | -42.1 -43.8 270 81 42 3.1 1.7
27000 -42.1 -43.8 255 69 35 1.8 1.0 | -41.1 -42.0 270 79 41 3.1 1.7
26000 -41.4 -42.5 255 66 34 4.2 2.3 | -40.2 -40.4 270 78 40 3.8 2.1
25000 -40.2 -40.4 255 63 33 4.0 2.2 | -39.0 -38.2 270 76 39 3.8 2.1
24000 -39.0 -38.2 255 61 31 4.0 2.2 | -37.9 -36.2 270 74 38 3.8 2.1
23000 -37.8 -36.0 255 58 30 4.0 2.2 | -36.7 -34.1 270 72 37 4.4 2.4
22000 -36.6 -33.9 255 53 27 4.0 2.2 | -35.4 -31.7 270 69 36 4.5 2.5
21000 -35.4 -31.7 255 48 25 4.2 2.3 | -34.0 -29.2 270 66 34 4.5 2.5
20000 -33.5 -28.3 255 45 23 9.0 4.9 | -32.4 -26.3 270 63 32 6.6 3.6
19500 -32.2 -26.0 260 46 23 9.0 5.0 | -31.5 -24.7 270 60 31 6.5 3.6
19000 -30.8 -23.4 260 46 24 9.0 5.0 | -30.5 -22.9 270 58 30 6.5 3.6
18500 -29.5 -21.1 260 46 24 9.1 5.0 | -29.5 -21.1 270 56 29 6.5 3.5
18000 -28.2 -18.8 260 46 24 9.3 5.1 | -28.5 -19.3 270 53 27 6.0 3.3
17500 -26.7 -16.1 260 46 24 9.6 5.2 | -27.4 -17.3 270 50 26 5.1 2.8
17000 -25.3 -13.5 260 46 24 9.6 5.3 | -26.6 -15.9 270 47 24 5.6 3.1
16500 -23.9 -11.0 260 44 23 9.0 5.0 | -25.7 -14.3 270 46 24 6.3 3.4
16000 -21.9 -7.4 255 39 20 8.9 4.9 | -24.8 -12.6 265 44 23 7.0 3.8
15500 -20.7 -5.3 255 36 18 8.3 4.5 | -23.5 -10.3 265 40 21 9.6 5.3
15000 -19.5 -3.1 255 33 17 8.4 4.6 | -22.1 -7.8 265 35 18 9.6 5.3
14500 -18.1 -0.6 255 31 16 10.8 5.9 | -20.5 -4.9 260 32 16 12.4 6.8
14000 -16.9 1.6 255 29 15 4.4 2.4 | -19.2 -2.6 260 31 16 4.5 2.5
13500 -15.9 3.4 255 28 14 9.4 5.2 | -18.2 -0.8 265 32 17 7.6 4.2
13000 -14.6 5.7 260 27 14 5.9 3.2 | -17.1 1.2 270 34 18 4.6 2.5
12500 -13.7 7.3 265 25 13 7.7 4.2 | -16.3 2.7 275 32 17 8.9 4.9
12000 -12.6 9.3 265 24 12 7.1 3.9 | -15.1 4.8 275 29 15 8.3 4.6
11750 -12.2 10.0 270 23 12 6.3 3.4 | -14.4 6.1 275 27 14 9.1 5.0
11500 -11.7 10.9 270 22 11 6.1 3.4 | -13.7 7.3 275 27 14 9.6 5.3
11250 -11.2 11.8 270 22 11 6.3 3.5 | -13.0 8.6 275 26 14 9.4 5.2
11000 -10.8 12.6 275 21 11 6.1 3.3 | -12.3 9.9 280 26 13 9.7 5.3
10750 -10.3 13.5 275 21 11 7.0 3.8 | -11.5 11.3 280 25 13 11.0 6.1
10500 -9.8 14.4 275 20 10 6.3 3.4 | -10.7 12.7 280 25 13 11.1 6.1
10250 -9.4 15.1 275 20 10 4.8 2.6 | -9.9 14.2 280 24 12 10.3 5.6
10000 -9.0 15.8 275 19 10 5.3 2.9 | -9.1 15.6 280 24 12 10.6 5.8
9750 -8.6 16.5 275 18 9 7.2 3.9 | -8.3 17.1 280 23 12 10.9 6.0
9500 -7.9 17.8 270 16 8 10.7 5.9 | -7.4 18.7 280 22 11 16.3 9.0
9250 -7.1 19.2 265 12 6 12.6 6.9 | -5.8 21.6 280 19 10 24.8 13.6
9000 M M M M M M M | -4.2 24.4 280 16 8 10.0 5.5
8750 M M M M M M M | M M M M M M M
8500 M M M M M M M | M M M M M M M
8250 M M M M M M M | M M M M M M M
8000 M M M M M M M | M M M M M M M
11/19/2024 AT 1400 MST | 11/19/2024 AT 1700 MST
|
CAPE... +1.6 LI... +3.5 | CAPE... 0.0 LI... +6.0
CINH... 0.0 K INDEX... -30.4 | CINH... 0.0 K INDEX... -42.2
|
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 -55.0 -67.0 245 56 29 0.7 0.4 | -55.3 -67.5 260 61 31 0.0 0.0
45000 -53.9 -65.0 260 71 37 0.7 0.4 | -55.3 -67.5 270 79 41 -0.1 -0.0
40000 -52.0 -61.6 255 65 34 1.4 0.8 | -52.9 -63.2 265 62 32 1.7 0.9
38000 -50.9 -59.6 255 64 33 3.4 1.9 | -52.2 -62.0 270 59 30 -0.1 -0.1
36000 -48.9 -56.0 270 71 37 3.3 1.8 | -52.3 -62.1 285 73 37 -0.2 -0.1
34000 -46.9 -52.4 280 82 42 3.3 1.8 | -52.4 -62.3 300 91 47 -0.6 -0.3
32000 -45.4 -49.7 290 84 43 1.9 1.1 | -50.4 -58.7 305 98 51 4.0 2.2
30000 -44.3 -47.7 290 83 43 1.8 1.0 | -47.6 -53.7 305 104 54 5.3 2.9
29000 -43.5 -46.3 290 82 42 2.9 1.6 | -45.7 -50.3 305 104 54 6.5 3.6
28000 -42.6 -44.7 290 82 42 2.9 1.6 | -43.7 -46.7 305 104 54 6.5 3.6
27000 -41.7 -43.1 285 81 42 2.9 1.6 | -41.8 -43.2 305 105 54 6.5 3.6
26000 -40.8 -41.4 285 81 42 4.3 2.4 | -39.3 -38.7 300 102 52 9.6 5.2
25000 -39.5 -39.1 285 82 42 4.2 2.3 | -36.4 -33.5 300 96 50 9.6 5.3
24000 -38.3 -36.9 285 84 43 4.2 2.3 | -33.5 -28.3 305 91 47 9.6 5.2
23000 -36.9 -34.4 285 84 43 6.0 3.3 | -30.9 -23.6 305 89 46 7.7 4.2
22000 -35.1 -31.2 285 84 43 5.9 3.3 | -28.6 -19.5 305 91 47 7.6 4.2
21000 -33.4 -28.1 285 83 43 5.9 3.3 | -26.3 -15.3 305 93 48 8.0 4.4
20000 -31.6 -24.9 285 81 42 6.1 3.3 | -24.8 -12.6 305 91 47 3.7 2.0
19500 -30.6 -23.1 285 79 41 6.1 3.3 | -24.3 -11.7 300 89 46 3.7 2.0
19000 -29.7 -21.5 285 78 40 6.1 3.3 | -23.7 -10.7 300 88 45 3.7 2.0
18500 -28.8 -19.8 285 76 39 6.1 3.3 | -23.2 -9.8 300 86 44 3.7 2.0
18000 -27.9 -18.2 285 75 38 6.1 3.3 | -22.7 -8.9 300 84 43 2.9 1.6
17500 -27.0 -16.6 285 69 35 6.1 3.3 | -22.3 -8.1 300 81 42 2.7 1.5
17000 -26.1 -15.0 285 63 32 6.0 3.3 | -21.9 -7.4 300 78 40 2.7 1.5
16500 -25.3 -13.5 285 59 31 4.1 2.3 | -21.5 -6.7 300 76 39 2.6 1.4
16000 -24.4 -11.9 290 57 29 4.5 2.5 | -21.1 -6.0 300 73 37 2.6 1.4
15500 -23.7 -10.7 290 53 27 4.9 2.7 | -20.5 -4.9 300 67 34 2.7 1.5
15000 -22.9 -9.2 290 49 25 5.3 2.9 | -20.1 -4.2 300 62 32 2.7 1.5
14500 -21.9 -7.4 290 45 23 8.6 4.7 | -19.6 -3.3 300 56 29 3.0 1.6
14000 -20.9 -5.6 285 41 21 4.0 2.2 | -19.3 -2.7 300 51 26 2.3 1.3
13500 -19.9 -3.8 285 37 19 9.4 5.1 | -18.8 -1.8 300 47 24 3.8 2.1
13000 -18.6 -1.5 285 34 18 8.9 4.9 | -18.2 -0.8 300 42 22 3.6 2.0
12500 -17.2 1.0 280 33 17 9.6 5.3 | -17.5 0.5 295 38 20 6.5 3.6
12000 -15.8 3.6 280 33 17 9.1 5.0 | -16.6 2.1 290 35 18 7.1 3.9
11750 -15.1 4.8 280 32 17 9.5 5.2 | -16.0 3.2 290 34 17 9.1 5.0
11500 -14.4 6.1 280 32 16 10.4 5.7 | -15.3 4.5 290 33 17 9.6 5.3
11250 -13.6 7.5 280 31 16 10.2 5.6 | -14.6 5.7 290 32 16 9.5 5.2
11000 -12.8 9.0 280 31 16 10.2 5.6 | -13.9 7.0 285 31 16 9.4 5.2
10750 -12.1 10.2 280 31 16 10.1 5.5 | -13.2 8.2 285 30 15 9.6 5.2
10500 -11.3 11.7 280 30 15 10.3 5.6 | -12.4 9.7 285 29 15 10.0 5.5
10250 -10.6 12.9 280 29 15 10.1 5.6 | -11.7 10.9 285 28 14 10.3 5.6
10000 -9.8 14.4 280 29 15 11.0 6.0 | -10.9 12.4 285 27 14 9.4 5.2
9750 -8.9 16.0 280 28 14 12.8 7.0 | -10.3 13.5 285 25 13 8.6 4.7
9500 -8.0 17.6 280 26 14 9.8 5.4 | -9.6 14.7 285 24 12 8.7 4.8
9250 -7.3 18.9 280 24 12 11.5 6.3 | -9.0 15.8 285 21 11 7.9 4.3
9000 -5.1 22.8 280 18 10 59.7 32.8 | -8.5 16.7 280 14 7 6.6 3.6
8750 M M M M M M M | M M M M M M M
8500 M M M M M M M | M M M M M M M
8250 M M M M M M M | M M M M M M M
8000 M M M M M M M | M M M M M M M
________________________________________________________________________________
THIS PRODUCT IS ISSUED TWICE PER DAY, ONCE 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 RAWINSONDE OBSERVATION AND/OR
NUMERICAL WEATHER PREDICTION MODEL DATA TAKEN NEAR VILLA GROVE, COLORADO AT:
NORTH LATITUDE: 38 DEG 16 MIN 03 SEC
WEST LONGITUDE: 105 DEG 53 MIN 37 SEC
ELEVATION: 7986 FEET (2434 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
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