Detailed Predictions for: South Mountain
Launch Altitude (f): 2600
LZ Altitude (f): 1400
Sounding

Station:

KTUS

Date/Time:

18 SEP 2018

Temp/Wind data from:

NOAA Digital Forecast

Site Forecasts
Time
(Local)
High
Temp

Puddle
Temp

Wind
(mph)
Thermal
Ceiling

(ft)
Soaring
Ceiling

(ft)
Above
Launch

(ft)
Thermal
Type
Thermal
Index

(F)
6 AM Tue 81 81 SW 5 0 2600 0 Blue 0
7 AM Tue 82 82 SW 6 0 2600 0 Blue 0
8 AM Tue 82 83 SW 7 0 2600 0 Blue 0
9 AM Tue 84 86 SW 7 2978 2600 0 Blue 3
10 AM Tue 86 90 SW 7 3477 3030 430 Blue 7
11 AM Tue 88 94 SW 6 6252 5278 2678 Blue 11
12 Noon Tue 92 98 W 6 8897 6870 4270 Blue 15
1 PM Tue 95 101 W 6 11537 8785 6185 Blue 18
2 PM Tue 97 102 W 7 12416 9400 6800 White 19
3 PM Tue 98 101 W 8 11537 8785 6185 Blue 18
4 PM Tue 99 100 W 9 10666 8201 5601 Blue 17
5 PM Tue 98 98 W 10 8897 6870 4270 Blue 15
6 PM Tue 97 97 W 12 8321 6214 3614 Blue 14
7 PM Tue 96 96 W 12 7664 5904 3304 Blue 13
8 PM Tue 92 92 W 12 5625 3163 563 Blue 9
9 PM Tue 91 91 W 12 5308 3084 484 Blue 8
10 PM Tue 88 88 W 13 3086 2923 323 Blue 5
11 PM Tue 87 87 W 13 3032 2643 43 Blue 4
12 Midnight Wed 86 86 W 14 2978 2600 0 Blue 3
1 AM Wed 85 85 W 13 2924 2600 0 Blue 2
2 AM Wed 83 83 W 13 0 2600 0 Blue 0
3 AM Wed 83 83 W 12 0 2600 0 Blue 0
4 AM Wed 82 82 W 9 0 2600 0 Blue 0
5 AM Wed 81 81 SW 8 0 2600 0 Blue 0
6 AM Wed 81 81 SW 7 0 2600 0 Blue 0
7 AM Wed 79 79 SW 6 0 2600 0 Blue 0
8 AM Wed 81 81 SW 6 0 2600 0 Blue 0
9 AM Wed 81 81 SW 6 0 2600 0 Blue 0
10 AM Wed 79 80 SW 6 0 2600 0 Blue 0
11 AM Wed 81 82 S 7 0 2600 0 Blue 0
12 Noon Wed 82 83 S 7 0 2600 0 Blue 0
1 PM Wed 81 82 S 8 0 2600 0 Blue 0
2 PM Wed 82 83 S 8 0 2600 0 Blue 0
3 PM Wed 84 85 SW 8 2924 2600 0 Blue 2
4 PM Wed 86 86 SW 8 2978 2600 0 Blue 3
5 PM Wed 85 85 SW 8 2924 2600 0 Blue 2
6 PM Wed 84 84 SW 8 2647 2600 0 Blue 1
7 PM Wed 82 82 SW 8 0 2600 0 Blue 0
8 PM Wed 81 81 S 9 0 2600 0 Blue 0
9 PM Wed 80 80 S 9 0 2600 0 Blue 0
10 PM Wed 79 79 S 9 0 2600 0 Blue 0
11 PM Wed 78 78 S 9 0 2600 0 Blue 0
12 Midnight Thu 77 77 S 8 0 2600 0 Blue 0
1 AM Thu 77 77 S 8 0 2600 0 Blue 0
2 AM Thu 77 77 S 7 0 2600 0 Blue 0
3 AM Thu 76 76 S 7 0 2600 0 Blue 0
4 AM Thu 75 75 S 6 0 2600 0 Blue 0
5 AM Thu 74 74 SW 6 0 2600 0 Blue 0
6 AM Thu 73 73 SW 5 0 2600 0 Blue 0
7 AM Thu 73 73 SW 5 0 2600 0 Blue 0
8 AM Thu 74 74 S 3 0 2600 0 Blue 0
9 AM Thu 75 76 S 3 0 2600 0 Blue 0
10 AM Thu 77 80 S 3 0 2600 0 Blue 0
11 AM Thu 79 83 SW 3 0 2600 0 Blue 0
12 Noon Thu 81 85 SW 3 2924 2600 0 Blue 2
1 PM Thu 84 88 SW 5 3086 2923 323 Blue 5
2 PM Thu 86 90 W 5 3477 3030 430 Blue 7
3 PM Thu 89 92 W 6 5625 3163 563 Blue 9
4 PM Thu 90 91 W 6 5308 3084 484 Blue 8
5 PM Thu 91 91 W 6 5308 3084 484 Blue 8
6 PM Thu 90 90 W 6 3477 3030 430 Blue 7
7 PM Thu 88 88 W 6 3086 2923 323 Blue 5
8 PM Thu 86 86 W 7 2978 2600 0 Blue 3
9 PM Thu 85 85 SW 7 2924 2600 0 Blue 2
10 PM Thu 84 84 SW 7 2647 2600 0 Blue 1
11 PM Thu 83 83 SW 8 0 2600 0 Blue 0
12 Midnight Fri 82 82 SW 8 0 2600 0 Blue 0
1 AM Fri 82 82 SW 7 0 2600 0 Blue 0
2 AM Fri 81 81 SW 7 0 2600 0 Blue 0
3 AM Fri 79 79 SW 6 0 2600 0 Blue 0
4 AM Fri 78 78 SW 6 0 2600 0 Blue 0
5 AM Fri 77 77 SW 7 0 2600 0 Blue 0
6 AM Fri 76 76 SW 7 0 2600 0 Blue 0
7 AM Fri 76 76 SW 7 0 2600 0 Blue 0
8 AM Fri 76 76 SW 7 0 2600 0 Blue 0
9 AM Fri 77 78 SW 6 0 2600 0 Blue 0
10 AM Fri 79 82 SW 6 0 2600 0 Blue 0
11 AM Fri 81 85 SW 5 2924 2600 0 Blue 2
12 Noon Fri 83 88 SW 5 3086 2923 323 Blue 5
1 PM Fri 86 91 SW 5 5308 3084 484 Blue 8
2 PM Fri 89 93 W 5 5939 3466 866 Blue 10
3 PM Fri 91 94 W 5 6252 5278 2678 Blue 11
4 PM Fri 92 93 W 6 5939 3466 866 Blue 10
5 PM Fri 92 92 W 6 5625 3163 563 Blue 9
6 PM Fri 91 91 W 6 5308 3084 484 Blue 8
7 PM Fri 89 89 W 6 3171 2976 376 Blue 6
8 PM Fri 88 88 W 7 3086 2923 323 Blue 5
9 PM Fri 86 86 W 7 2978 2600 0 Blue 3
10 PM Fri 85 85 W 7 2924 2600 0 Blue 2
11 PM Fri 84 84 SW 7 2647 2600 0 Blue 1
12 Midnight Sat 83 83 SW 7 0 2600 0 Blue 0
1 AM Sat 82 82 SW 7 0 2600 0 Blue 0
2 AM Sat 81 81 SW 6 0 2600 0 Blue 0
3 AM Sat 80 80 W 6 0 2600 0 Blue 0
4 AM Sat 79 79 W 5 0 2600 0 Blue 0
5 AM Sat 78 78 W 3 0 2600 0 Blue 0
6 AM Sat 78 78 W 3 0 2600 0 Blue 0
7 AM Sat 78 78 W 3 0 2600 0 Blue 0
8 AM Sat 79 79 NW 2 0 2600 0 Blue 0
9 AM Sat 80 81 N 2 0 2600 0 Blue 0
10 AM Sat 82 85 N 2 2924 2600 0 Blue 2
11 AM Sat 84 87 NE 2 3032 2643 43 Blue 4
12 Noon Sat 87 91 NE 2 5308 3084 484 Blue 8
1 PM Sat 90 94 NE 2 6252 5278 2678 Blue 11
2 PM Sat 93 96 N 3 7664 5904 3304 Blue 13
3 PM Sat 95 98 N 3 8897 6870 4270 Blue 15
4 PM Sat 96 97 NW 3 8321 6214 3614 Blue 14
5 PM Sat 96 96 W 5 7664 5904 3304 Blue 13
6 PM Sat 95 95 W 5 6972 5593 2993 Blue 12
7 PM Sat 93 93 W 5 5939 3466 866 Blue 10
8 PM Sat 91 91 W 5 5308 3084 484 Blue 8
9 PM Sat 89 89 W 5 3171 2976 376 Blue 6
10 PM Sat 87 87 W 5 3032 2643 43 Blue 4
11 PM Sat 86 86 W 5 2978 2600 0 Blue 3
12 Midnight Sun 85 85 W 5 2924 2600 0 Blue 2
1 AM Sun 84 84 W 5 2647 2600 0 Blue 1
2 AM Sun 82 82 NW 5 0 2600 0 Blue 0
3 AM Sun 81 81 NW 5 0 2600 0 Blue 0
4 AM Sun 80 80 N 5 0 2600 0 Blue 0
5 AM Sun 79 79 N 5 0 2600 0 Blue 0
6 AM Sun 79 79 NE 5 0 2600 0 Blue 0
7 AM Sun 80 80 NE 5 0 2600 0 Blue 0
8 AM Sun 80 80 NE 5 0 2600 0 Blue 0
9 AM Sun 82 84 E 5 2647 2600 0 Blue 1
10 AM Sun 84 87 E 5 3032 2643 43 Blue 4
11 AM Sun 87 91 E 5 5308 3084 484 Blue 8
12 Noon Sun 90 95 SE 5 6972 5593 2993 Blue 12
1 PM Sun 93 98 SE 5 8897 6870 4270 Blue 15
2 PM Sun 95 99 S 5 9493 7552 4952 Blue 16
3 PM Sun 97 100 S 5 10666 8201 5601 Blue 17
4 PM Sun 97 98 SW 5 8897 6870 4270 Blue 15
5 PM Sun 97 97 SW 5 8321 6214 3614 Blue 14
6 PM Sun 96 96 W 5 7664 5904 3304 Blue 13
7 PM Sun 94 94 W 5 6252 5278 2678 Blue 11
8 PM Sun 92 92 W 5 5625 3163 563 Blue 9
9 PM Sun 90 90 W 5 3477 3030 430 Blue 7
10 PM Sun 89 89 W 5 3171 2976 376 Blue 6
11 PM Sun 87 87 W 5 3032 2643 43 Blue 4
12 Midnight Mon 86 86 W 5 2978 2600 0 Blue 3
1 AM Mon 84 84 SW 5 2647 2600 0 Blue 1
2 AM Mon 83 83 SW 5 0 2600 0 Blue 0
3 AM Mon 81 81 SW 5 0 2600 0 Blue 0
4 AM Mon 80 80 S 5 0 2600 0 Blue 0
5 AM Mon 80 80 S 5 0 2600 0 Blue 0

DISCLAIMER: These estimates are intended to assist in daily site selection only.  No warranty is made concerning the accuracy of these estimates.  These estimates cannot be used to determine if conditions are safe for flying.  Conditions should be evaluated at the launch site by experienced pilots before launching.

Sounding: This is the site at which the weather balloon was released.  If the flying site predicted is far from the sounding site, the estimate is not valid.  Also, the sounding is done at 12Z (4AM PST).  If a front comes through, the sounding is no longer valid. The sounding becomes less valid later in the day.

Thermal Ceiling: the lower of the height at which the thermal stops rising and the cloud level.  We can't fly into the clouds, so it doesn't matter how much higher the thermal goes.  Remember that we can't get to the top of the thermal because of our sink rate.  Our upper limit will be lower than the reported ceiling.

Soaring Ceiling: We will stop going up when the thermal is rising just fast enough to offset our sink.  It is estimated that this happens when the temperature difference between the thermal and the surrounding air is about 2 degrees F. This number is an estimate of the maximum altitude we might reach if we start at launch height, and should be more reflective of our chances of soaring than the thermal top. Please let me know how this compares with actually flying, and I will adjust it as necessary.

Above Launch: The difference between how high we might get and how high we start. This estimate does not account for ridge lift.

High Temp: This estimate is taken from the National Weather Service website.  Puddle temperatures can exceed this temperature. 

Puddle Temp: This estimate is based on the High Temp and the National Weather Service estimate of cloudiness, and the angle of the sun.  When the sun is directly overhead on a sunny day, the puddle temp is esimated to be 25 degrees warmer than the high ambient temperature. This estimate now includes a rigorous calculation of the Sun Angle, and accounts for the seasonal differences in zenith and daylight hours.

Wind: This estimate is taken from the National Weather Service website.

Thermal Type: Blue (no cloud formation) or White (Cloud formation)

Thermal Index: This is the maximum difference in temperature between the rising packet of air (the thermal) and the surrounding air.  The difference in temperature is responsible for the buoyancy of the thermal, and larger temperature differences mean faster rising thermals.  A value of about 10 F or greater often means that the conditions are soarable.  Values above 20 could indicate rowdy thermals.

Validity of estimate: Many factors (including strong wind, fronts, cloud shadows, incorrectly predicted temperatures, etc) can affect the validity of the estimates. 

Author: Tad Hurst

Supported By: Alan Crouse ac_soaring@yahoo.com