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

Station:

KTUS

Date/Time:

21 JUL 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 Sat 84 84 S 8 3351 2660 60 Blue 7
7 AM Sat 84 84 SW 8 3351 2660 60 Blue 7
8 AM Sat 86 86 W 8 4043 2906 306 Blue 9
9 AM Sat 86 87 NW 8 4223 3337 737 Blue 10
10 AM Sat 87 89 NW 8 4818 4034 1434 Blue 12
11 AM Sat 90 93 W 8 5997 5692 3092 White 16
12 Noon Sat 91 95 W 8 6434 6092 3492 White 18
1 PM Sat 93 97 W 9 6870 6490 3890 White 20
2 PM Sat 95 99 W 10 7304 7304 4704 White 22
3 PM Sat 96 99 W 12 7304 7304 4704 White 22
4 PM Sat 98 100 W 12 7520 7520 4920 White 23
5 PM Sat 98 99 W 13 7304 7304 4704 White 22
6 PM Sat 96 96 W 13 6652 6291 3691 White 19
7 PM Sat 95 95 W 13 6434 6092 3492 White 18
8 PM Sat 95 95 W 12 6434 6092 3492 White 18
9 PM Sat 93 93 W 12 5997 5692 3092 White 16
10 PM Sat 92 92 W 12 5778 4721 2121 White 15
11 PM Sat 90 90 W 10 5337 4212 1612 White 13
12 Midnight Sun 90 90 W 10 5337 4212 1612 White 13
1 AM Sun 89 89 W 9 4818 4034 1434 Blue 12
2 AM Sun 88 88 W 8 4403 3761 1161 Blue 11
3 AM Sun 88 88 W 7 4403 3761 1161 Blue 11
4 AM Sun 87 87 W 6 4223 3337 737 Blue 10
5 AM Sun 87 87 W 6 4223 3337 737 Blue 10
6 AM Sun 86 86 W 5 4043 2906 306 Blue 9
7 AM Sun 86 86 W 5 4043 2906 306 Blue 9
8 AM Sun 87 88 W 5 4403 3761 1161 Blue 11
9 AM Sun 89 92 W 5 5778 4721 2121 White 15
10 AM Sun 91 95 W 5 6434 6092 3492 White 18
11 AM Sun 96 101 W 5 7737 7737 5137 White 24
12 Noon Sun 98 104 W 6 8381 8381 5781 White 27
1 PM Sun 101 107 W 7 9025 9025 6425 White 30
2 PM Sun 103 109 W 8 9454 9454 6854 White 32
3 PM Sun 104 108 W 9 9240 9240 6640 White 31
4 PM Sun 104 107 W 10 9025 9025 6425 White 30
5 PM Sun 104 105 W 12 8596 8596 5996 White 28
6 PM Sun 103 103 W 12 8166 8166 5566 White 26
7 PM Sun 102 102 W 12 7951 7951 5351 White 25
8 PM Sun 100 100 W 12 7520 7520 4920 White 23
9 PM Sun 99 99 W 12 7304 7304 4704 White 22
10 PM Sun 97 97 W 12 6870 6490 3890 White 20
11 PM Sun 96 96 W 12 6652 6291 3691 White 19
12 Midnight Mon 94 94 W 12 6216 5892 3292 White 17
1 AM Mon 93 93 W 10 5997 5692 3092 White 16
2 AM Mon 92 92 W 9 5778 4721 2121 White 15
3 AM Mon 91 91 W 8 5558 4391 1791 White 14
4 AM Mon 90 90 W 8 5337 4212 1612 White 13
5 AM Mon 89 89 W 7 4818 4034 1434 Blue 12
6 AM Mon 88 88 W 6 4403 3761 1161 Blue 11
7 AM Mon 88 88 W 6 4403 3761 1161 Blue 11
8 AM Mon 89 90 W 5 5337 4212 1612 White 13
9 AM Mon 91 94 W 5 6216 5892 3292 White 17
10 AM Mon 94 98 W 5 7088 6688 4088 White 21
11 AM Mon 98 104 W 5 8381 8381 5781 White 27
12 Noon Mon 101 107 W 5 9025 9025 6425 White 30
1 PM Mon 105 112 W 5 10094 10094 7494 White 35
2 PM Mon 107 113 W 6 10308 10308 7708 White 36
3 PM Mon 109 114 W 7 10519 10519 7919 White 37
4 PM Mon 109 112 W 8 10094 10094 7494 White 35
5 PM Mon 109 111 W 9 9882 9882 7282 White 34
6 PM Mon 108 108 W 10 9240 9240 6640 White 31
7 PM Mon 106 106 W 12 8811 8811 6211 White 29
8 PM Mon 104 104 W 13 8381 8381 5781 White 27
9 PM Mon 102 102 W 13 7951 7951 5351 White 25
10 PM Mon 100 100 W 14 7520 7520 4920 White 23
11 PM Mon 98 98 W 14 7088 6688 4088 White 21
12 Midnight Tue 96 96 W 13 6652 6291 3691 White 19
1 AM Tue 94 94 W 12 6216 5892 3292 White 17
2 AM Tue 93 93 W 10 5997 5692 3092 White 16
3 AM Tue 92 92 NW 8 5778 4721 2121 White 15
4 AM Tue 91 91 NW 6 5558 4391 1791 White 14
5 AM Tue 90 90 N 5 5337 4212 1612 White 13
6 AM Tue 89 89 N 3 4818 4034 1434 Blue 12
7 AM Tue 89 89 N 2 4818 4034 1434 Blue 12
8 AM Tue 90 91 NE 3 5558 4391 1791 White 14
9 AM Tue 93 96 NE 3 6652 6291 3691 White 19
10 AM Tue 96 101 E 5 7737 7737 5137 White 24
11 AM Tue 100 107 E 6 9025 9025 6425 White 30
12 Noon Tue 104 112 SE 7 10094 10094 7494 White 35
1 PM Tue 107 115 SE 8 10725 10725 8125 White 38
2 PM Tue 110 117 S 8 11135 11135 8535 White 40
3 PM Tue 112 117 S 9 11135 11135 8535 White 40
4 PM Tue 112 115 SW 10 10725 10725 8125 White 38
5 PM Tue 112 114 W 10 10519 10519 7919 White 37
6 PM Tue 111 111 W 10 9882 9882 7282 White 34
7 PM Tue 109 109 W 12 9454 9454 6854 White 32
8 PM Tue 107 107 W 12 9025 9025 6425 White 30
9 PM Tue 104 104 W 13 8381 8381 5781 White 27
10 PM Tue 102 102 W 13 7951 7951 5351 White 25
11 PM Tue 100 100 W 13 7520 7520 4920 White 23
12 Midnight Wed 99 99 W 13 7304 7304 4704 White 22
1 AM Wed 98 98 SW 12 7088 6688 4088 White 21
2 AM Wed 97 97 SW 12 6870 6490 3890 White 20
3 AM Wed 95 95 S 10 6434 6092 3492 White 18
4 AM Wed 94 94 S 9 6216 5892 3292 White 17
5 AM Wed 92 92 SE 8 5778 4721 2121 White 15
6 AM Wed 91 91 SE 7 5558 4391 1791 White 14
7 AM Wed 91 91 SE 7 5558 4391 1791 White 14
8 AM Wed 92 93 S 6 5997 5692 3092 White 16
9 AM Wed 93 95 S 6 6434 6092 3492 White 18
10 AM Wed 96 100 S 5 7520 7520 4920 White 23
11 AM Wed 100 105 SW 5 8596 8596 5996 White 28
12 Noon Wed 103 109 SW 6 9454 9454 6854 White 32
1 PM Wed 107 113 SW 6 10308 10308 7708 White 36
2 PM Wed 109 114 SW 8 10519 10519 7919 White 37
3 PM Wed 111 115 W 9 10725 10725 8125 White 38
4 PM Wed 111 113 W 10 10308 10308 7708 White 36
5 PM Wed 111 112 W 12 10094 10094 7494 White 35
6 PM Wed 110 110 W 13 9668 9668 7068 White 33
7 PM Wed 108 108 W 14 9240 9240 6640 White 31
8 PM Wed 106 106 W 15 8811 8811 6211 White 29
9 PM Wed 104 104 W 15 8381 8381 5781 White 27
10 PM Wed 103 103 W 16 8166 8166 5566 White 26
11 PM Wed 101 101 SW 15 7737 7737 5137 White 24
12 Midnight Thu 99 99 SW 15 7304 7304 4704 White 22
1 AM Thu 97 97 SW 14 6870 6490 3890 White 20
2 AM Thu 95 95 SW 13 6434 6092 3492 White 18
3 AM Thu 93 93 S 10 5997 5692 3092 White 16
4 AM Thu 92 92 S 9 5778 4721 2121 White 15
5 AM Thu 91 91 S 8 5558 4391 1791 White 14
6 AM Thu 90 90 S 7 5337 4212 1612 White 13
7 AM Thu 90 90 S 6 5337 4212 1612 White 13
8 AM Thu 91 92 S 6 5778 4721 2121 White 15
9 AM Thu 92 94 S 7 6216 5892 3292 White 17
10 AM Thu 94 97 SW 7 6870 6490 3890 White 20
11 AM Thu 96 100 SW 8 7520 7520 4920 White 23
12 Noon Thu 98 102 SW 8 7951 7951 5351 White 25
1 PM Thu 101 106 SW 9 8811 8811 6211 White 29
2 PM Thu 103 107 SW 10 9025 9025 6425 White 30
3 PM Thu 104 107 SW 12 9025 9025 6425 White 30
4 PM Thu 104 106 W 13 8811 8811 6211 White 29
5 PM Thu 104 105 W 13 8596 8596 5996 White 28
6 PM Thu 103 103 W 14 8166 8166 5566 White 26
7 PM Thu 102 102 W 14 7951 7951 5351 White 25
8 PM Thu 100 100 SW 14 7520 7520 4920 White 23
9 PM Thu 98 98 SW 14 7088 6688 4088 White 21
10 PM Thu 96 96 SW 14 6652 6291 3691 White 19
11 PM Thu 94 94 SW 14 6216 5892 3292 White 17
12 Midnight Fri 93 93 SW 13 5997 5692 3092 White 16
1 AM Fri 92 92 SW 12 5778 4721 2121 White 15
2 AM Fri 91 91 SW 10 5558 4391 1791 White 14
3 AM Fri 90 90 SW 9 5337 4212 1612 White 13
4 AM Fri 89 89 SW 8 4818 4034 1434 Blue 12
5 AM Fri 88 88 SW 7 4403 3761 1161 Blue 11

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