Detailed Predictions for: Rainbow Valley
Launch Altitude (f): 1125
LZ Altitude (f): 80
Sounding

Station:

KTUS

Date/Time:

16 JUL 2019

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 87 87 SW 3 0 1125 0 Blue 0
7 AM Tue 86 86 S 2 0 1125 0 Blue 0
8 AM Tue 91 93 SW 2 2528 2470 1345 Blue 0
9 AM Tue 97 101 SW 3 3284 3058 1933 Blue 8
10 AM Tue 100 106 SW 5 6482 4117 2992 Blue 13
11 AM Tue 103 111 SW 5 10277 7986 6861 Blue 18
12 Noon Tue 107 116 SW 6 14445 11385 10260 White 23
1 PM Tue 109 118 SW 7 14846 14846 13721 White 25
2 PM Tue 111 119 SW 8 15045 15045 13920 White 26
3 PM Tue 112 118 SW 10 14846 14846 13721 White 25
4 PM Tue 112 116 SW 10 14445 11385 10260 White 23
5 PM Tue 113 115 W 12 14245 10875 9750 White 22
6 PM Tue 112 112 W 13 11037 8728 7603 Blue 19
7 PM Tue 110 110 W 13 9608 7193 6068 Blue 17
8 PM Tue 109 109 SW 12 8902 6335 5210 Blue 16
9 PM Tue 104 104 SW 9 5121 3268 2143 Blue 11
10 PM Tue 100 100 SW 6 3166 3005 1880 Blue 7
11 PM Tue 97 97 SW 6 3008 2847 1722 Blue 4
12 Midnight Wed 96 96 SW 5 2956 2497 1372 Blue 3
1 AM Wed 94 94 SW 5 2850 2470 1345 Blue 1
2 AM Wed 92 92 W 5 0 1125 0 Blue 0
3 AM Wed 89 89 SW 5 0 1125 0 Blue 0
4 AM Wed 88 88 W 3 0 1125 0 Blue 0
5 AM Wed 87 87 SW 2 0 1125 0 Blue 0
6 AM Wed 85 85 SE 2 0 1125 0 Blue 0
7 AM Wed 84 84 SE 2 0 1125 0 Blue 0
8 AM Wed 87 89 SE 2 0 1125 0 Blue 0
9 AM Wed 92 96 S 2 2956 2497 1372 Blue 3
10 AM Wed 96 102 S 3 3534 3111 1986 Blue 9
11 AM Wed 98 106 S 3 6482 4117 2992 Blue 13
12 Noon Wed 101 110 S 5 9608 7193 6068 Blue 17
1 PM Wed 104 113 S 6 11552 9427 8302 Blue 20
2 PM Wed 106 114 SW 7 14045 10091 8966 White 21
3 PM Wed 107 113 SW 8 11552 9427 8302 Blue 20
4 PM Wed 108 112 SW 9 11037 8728 7603 Blue 19
5 PM Wed 109 111 SW 10 10277 7986 6861 Blue 18
6 PM Wed 108 108 SW 12 8153 5633 4508 Blue 15
7 PM Wed 106 106 SW 12 6482 4117 2992 Blue 13
8 PM Wed 103 103 SW 10 4215 3163 2038 Blue 10
9 PM Wed 100 100 SW 9 3166 3005 1880 Blue 7
10 PM Wed 97 97 SW 7 3008 2847 1722 Blue 4
11 PM Wed 95 95 SW 5 2903 2470 1345 Blue 2
12 Midnight Thu 93 93 SW 3 2528 2470 1345 Blue 0
1 AM Thu 91 91 SW 3 0 1125 0 Blue 0
2 AM Thu 90 90 SW 3 0 1125 0 Blue 0
3 AM Thu 88 88 SW 3 0 1125 0 Blue 0
4 AM Thu 86 86 SW 3 0 1125 0 Blue 0
5 AM Thu 84 84 S 2 0 1125 0 Blue 0
6 AM Thu 83 83 S 2 0 1125 0 Blue 0
7 AM Thu 84 84 S 2 0 1125 0 Blue 0
8 AM Thu 87 87 SE 2 0 1125 0 Blue 0
9 AM Thu 90 90 SE 2 0 1125 0 Blue 0
10 AM Thu 93 94 S 2 2850 2470 1345 Blue 1
11 AM Thu 95 97 SW 3 3008 2847 1722 Blue 4
12 Noon Thu 98 102 SW 3 3534 3111 1986 Blue 9
1 PM Thu 100 104 SW 5 5121 3268 2143 Blue 11
2 PM Thu 102 106 SW 5 6482 4117 2992 Blue 13
3 PM Thu 104 107 SW 6 7351 5049 3924 Blue 14
4 PM Thu 105 107 W 7 7351 5049 3924 Blue 14
5 PM Thu 106 107 W 8 7351 5049 3924 Blue 14
6 PM Thu 106 106 W 9 6482 4117 2992 Blue 13
7 PM Thu 104 104 W 9 5121 3268 2143 Blue 11
8 PM Thu 102 102 W 8 3534 3111 1986 Blue 9
9 PM Thu 99 99 SW 7 3114 2953 1828 Blue 6
10 PM Thu 97 97 SW 6 3008 2847 1722 Blue 4
11 PM Thu 95 95 SW 5 2903 2470 1345 Blue 2
12 Midnight Fri 93 93 SW 3 2528 2470 1345 Blue 0
1 AM Fri 91 91 SW 3 0 1125 0 Blue 0
2 AM Fri 89 89 SW 5 0 1125 0 Blue 0
3 AM Fri 87 87 SW 5 0 1125 0 Blue 0
4 AM Fri 85 85 SW 3 0 1125 0 Blue 0
5 AM Fri 83 83 SW 3 0 1125 0 Blue 0
6 AM Fri 83 83 SW 2 0 1125 0 Blue 0
7 AM Fri 84 84 SW 2 0 1125 0 Blue 0
8 AM Fri 87 88 SW 2 0 1125 0 Blue 0
9 AM Fri 90 92 SW 2 0 1125 0 Blue 0
10 AM Fri 93 97 SW 2 3008 2847 1722 Blue 4
11 AM Fri 96 101 SW 2 3284 3058 1933 Blue 8
12 Noon Fri 99 106 SW 2 6482 4117 2992 Blue 13
1 PM Fri 102 109 SW 3 8902 6335 5210 Blue 16
2 PM Fri 104 110 SW 5 9608 7193 6068 Blue 17
3 PM Fri 105 109 SW 6 8902 6335 5210 Blue 16
4 PM Fri 106 109 W 7 8902 6335 5210 Blue 16
5 PM Fri 106 107 W 8 7351 5049 3924 Blue 14
6 PM Fri 106 106 W 9 6482 4117 2992 Blue 13
7 PM Fri 105 105 W 8 5714 3516 2391 Blue 12
8 PM Fri 102 102 W 7 3534 3111 1986 Blue 9
9 PM Fri 100 100 W 6 3166 3005 1880 Blue 7
10 PM Fri 98 98 W 5 3061 2900 1775 Blue 5
11 PM Fri 95 95 SW 3 2903 2470 1345 Blue 2
12 Midnight Sat 93 93 SW 3 2528 2470 1345 Blue 0
1 AM Sat 91 91 SW 3 0 1125 0 Blue 0
2 AM Sat 90 90 SW 3 0 1125 0 Blue 0
3 AM Sat 89 89 SW 3 0 1125 0 Blue 0
4 AM Sat 87 87 SW 3 0 1125 0 Blue 0
5 AM Sat 85 85 SW 3 0 1125 0 Blue 0
6 AM Sat 84 84 SW 3 0 1125 0 Blue 0
7 AM Sat 85 85 SW 3 0 1125 0 Blue 0
8 AM Sat 88 89 SW 3 0 1125 0 Blue 0
9 AM Sat 91 94 SW 3 2850 2470 1345 Blue 1
10 AM Sat 94 99 SW 3 3114 2953 1828 Blue 6
11 AM Sat 96 102 SW 5 3534 3111 1986 Blue 9
12 Noon Sat 99 106 SW 5 6482 4117 2992 Blue 13
1 PM Sat 101 108 SW 6 8153 5633 4508 Blue 15
2 PM Sat 104 110 W 6 9608 7193 6068 Blue 17
3 PM Sat 105 110 W 7 9608 7193 6068 Blue 17
4 PM Sat 106 109 W 8 8902 6335 5210 Blue 16
5 PM Sat 107 108 W 8 8153 5633 4508 Blue 15
6 PM Sat 106 106 W 9 6482 4117 2992 Blue 13
7 PM Sat 104 104 W 9 5121 3268 2143 Blue 11
8 PM Sat 102 102 W 9 3534 3111 1986 Blue 9
9 PM Sat 99 99 SW 9 3114 2953 1828 Blue 6
10 PM Sat 97 97 SW 8 3008 2847 1722 Blue 4
11 PM Sat 94 94 SW 7 2850 2470 1345 Blue 1
12 Midnight Sun 92 92 SW 6 0 1125 0 Blue 0
1 AM Sun 90 90 SW 6 0 1125 0 Blue 0
2 AM Sun 88 88 W 5 0 1125 0 Blue 0
3 AM Sun 87 87 W 5 0 1125 0 Blue 0
4 AM Sun 85 85 SW 3 0 1125 0 Blue 0
5 AM Sun 83 83 SW 3 0 1125 0 Blue 0
6 AM Sun 83 83 S 2 0 1125 0 Blue 0
7 AM Sun 84 84 S 2 0 1125 0 Blue 0
8 AM Sun 86 86 S 2 0 1125 0 Blue 0
9 AM Sun 89 90 S 2 0 1125 0 Blue 0
10 AM Sun 92 94 S 2 2850 2470 1345 Blue 1
11 AM Sun 94 97 SW 3 3008 2847 1722 Blue 4
12 Noon Sun 97 101 SW 3 3284 3058 1933 Blue 8
1 PM Sun 99 103 SW 5 4215 3163 2038 Blue 10
2 PM Sun 101 104 SW 5 5121 3268 2143 Blue 11
3 PM Sun 102 105 W 6 5714 3516 2391 Blue 12
4 PM Sun 103 105 W 7 5714 3516 2391 Blue 12
5 PM Sun 104 105 W 8 5714 3516 2391 Blue 12
6 PM Sun 104 104 W 8 5121 3268 2143 Blue 11
7 PM Sun 103 103 W 8 4215 3163 2038 Blue 10
8 PM Sun 100 100 W 7 3166 3005 1880 Blue 7
9 PM Sun 98 98 W 7 3061 2900 1775 Blue 5
10 PM Sun 96 96 W 7 2956 2497 1372 Blue 3
11 PM Sun 94 94 SW 6 2850 2470 1345 Blue 1
12 Midnight Mon 92 92 SW 6 0 1125 0 Blue 0
1 AM Mon 90 90 SW 5 0 1125 0 Blue 0
2 AM Mon 89 89 SW 5 0 1125 0 Blue 0
3 AM Mon 88 88 SW 3 0 1125 0 Blue 0
4 AM Mon 87 87 SW 3 0 1125 0 Blue 0
5 AM Mon 85 85 SW 3 0 1125 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