Detailed Predictions for: Rainbow Valley
Launch Altitude (f): 1125
LZ Altitude (f): 80
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 7 0 1125 0 Blue 0
7 AM Tue 85 85 SW 7 0 1125 0 Blue 0
8 AM Tue 79 80 SW 8 0 1125 0 Blue 0
9 AM Tue 86 88 SW 8 0 1125 0 Blue 0
10 AM Tue 89 93 SW 8 3034 2661 1536 Blue 4
11 AM Tue 92 98 SW 8 5609 3160 2035 Blue 9
12 Noon Tue 95 101 W 8 6898 5567 4442 Blue 12
1 PM Tue 98 104 W 8 8805 6776 5651 Blue 15
2 PM Tue 100 105 W 8 9415 7448 6323 Blue 16
3 PM Tue 101 104 W 9 8805 6776 5651 Blue 15
4 PM Tue 103 105 W 10 9415 7448 6323 Blue 16
5 PM Tue 102 102 W 10 7579 5874 4749 Blue 13
6 PM Tue 102 102 W 12 7579 5874 4749 Blue 13
7 PM Tue 101 101 W 12 6898 5567 4442 Blue 12
8 PM Tue 100 100 W 10 6226 5257 4132 Blue 11
9 PM Tue 97 97 SW 10 5297 3085 1960 Blue 8
10 PM Tue 94 94 SW 10 3088 2924 1799 Blue 5
11 PM Tue 92 92 SW 12 2981 2470 1345 Blue 3
12 Midnight Wed 91 91 SW 12 2927 2470 1345 Blue 2
1 AM Wed 89 89 SW 10 2473 2470 1345 Blue 0
2 AM Wed 87 87 SW 10 0 1125 0 Blue 0
3 AM Wed 87 87 SW 9 0 1125 0 Blue 0
4 AM Wed 85 85 SW 8 0 1125 0 Blue 0
5 AM Wed 85 85 SW 7 0 1125 0 Blue 0
6 AM Wed 85 85 SW 6 0 1125 0 Blue 0
7 AM Wed 83 83 SW 6 0 1125 0 Blue 0
8 AM Wed 82 82 SW 6 0 1125 0 Blue 0
9 AM Wed 85 85 S 6 0 1125 0 Blue 0
10 AM Wed 87 88 S 7 0 1125 0 Blue 0
11 AM Wed 87 88 S 9 0 1125 0 Blue 0
12 Noon Wed 89 90 S 9 2676 2470 1345 Blue 1
1 PM Wed 87 88 S 9 0 1125 0 Blue 0
2 PM Wed 88 89 S 9 2473 2470 1345 Blue 0
3 PM Wed 90 91 S 8 2927 2470 1345 Blue 2
4 PM Wed 91 92 S 8 2981 2470 1345 Blue 3
5 PM Wed 91 91 S 9 2927 2470 1345 Blue 2
6 PM Wed 90 90 S 9 2676 2470 1345 Blue 1
7 PM Wed 89 89 S 9 2473 2470 1345 Blue 0
8 PM Wed 88 88 S 10 0 1125 0 Blue 0
9 PM Wed 87 87 S 9 0 1125 0 Blue 0
10 PM Wed 85 85 S 8 0 1125 0 Blue 0
11 PM Wed 84 84 S 7 0 1125 0 Blue 0
12 Midnight Thu 83 83 S 6 0 1125 0 Blue 0
1 AM Thu 82 82 S 6 0 1125 0 Blue 0
2 AM Thu 81 81 S 5 0 1125 0 Blue 0
3 AM Thu 80 80 S 5 0 1125 0 Blue 0
4 AM Thu 80 80 S 3 0 1125 0 Blue 0
5 AM Thu 79 79 S 2 0 1125 0 Blue 0
6 AM Thu 79 79 SW 1 0 1125 0 Blue 0
7 AM Thu 79 79 S 1 0 1125 0 Blue 0
8 AM Thu 80 80 S 2 0 1125 0 Blue 0
9 AM Thu 81 82 S 2 0 1125 0 Blue 0
10 AM Thu 83 85 S 2 0 1125 0 Blue 0
11 AM Thu 85 89 W 1 2473 2470 1345 Blue 0
12 Noon Thu 87 91 W 1 2927 2470 1345 Blue 2
1 PM Thu 90 94 W 2 3088 2924 1799 Blue 5
2 PM Thu 92 96 W 3 3479 3031 1906 Blue 7
3 PM Thu 93 96 SW 5 3479 3031 1906 Blue 7
4 PM Thu 95 96 SW 5 3479 3031 1906 Blue 7
5 PM Thu 95 95 SW 5 3178 2978 1853 Blue 6
6 PM Thu 95 95 SW 5 3178 2978 1853 Blue 6
7 PM Thu 94 94 SW 5 3088 2924 1799 Blue 5
8 PM Thu 93 93 SW 6 3034 2661 1536 Blue 4
9 PM Thu 91 91 SW 6 2927 2470 1345 Blue 2
10 PM Thu 89 89 SW 6 2473 2470 1345 Blue 0
11 PM Thu 87 87 SW 6 0 1125 0 Blue 0
12 Midnight Fri 86 86 SW 6 0 1125 0 Blue 0
1 AM Fri 84 84 SW 6 0 1125 0 Blue 0
2 AM Fri 83 83 SW 6 0 1125 0 Blue 0
3 AM Fri 82 82 SW 6 0 1125 0 Blue 0
4 AM Fri 81 81 SW 6 0 1125 0 Blue 0
5 AM Fri 80 80 SW 6 0 1125 0 Blue 0
6 AM Fri 80 80 SW 6 0 1125 0 Blue 0
7 AM Fri 79 79 SW 6 0 1125 0 Blue 0
8 AM Fri 80 80 SW 6 0 1125 0 Blue 0
9 AM Fri 82 83 SW 6 0 1125 0 Blue 0
10 AM Fri 84 86 SW 5 0 1125 0 Blue 0
11 AM Fri 87 91 SW 5 2927 2470 1345 Blue 2
12 Noon Fri 90 95 SW 5 3178 2978 1853 Blue 6
1 PM Fri 92 97 SW 5 5297 3085 1960 Blue 8
2 PM Fri 95 99 SW 5 5919 3458 2333 Blue 10
3 PM Fri 96 99 W 5 5919 3458 2333 Blue 10
4 PM Fri 97 99 W 5 5919 3458 2333 Blue 10
5 PM Fri 97 97 W 5 5297 3085 1960 Blue 8
6 PM Fri 97 97 W 5 5297 3085 1960 Blue 8
7 PM Fri 96 96 W 5 3479 3031 1906 Blue 7
8 PM Fri 94 94 W 5 3088 2924 1799 Blue 5
9 PM Fri 93 93 SW 5 3034 2661 1536 Blue 4
10 PM Fri 91 91 SW 5 2927 2470 1345 Blue 2
11 PM Fri 89 89 SW 5 2473 2470 1345 Blue 0
12 Midnight Sat 87 87 SW 5 0 1125 0 Blue 0
1 AM Sat 85 85 SW 5 0 1125 0 Blue 0
2 AM Sat 84 84 SW 3 0 1125 0 Blue 0
3 AM Sat 82 82 SW 3 0 1125 0 Blue 0
4 AM Sat 81 81 S 3 0 1125 0 Blue 0
5 AM Sat 80 80 S 2 0 1125 0 Blue 0
6 AM Sat 80 80 S 2 0 1125 0 Blue 0
7 AM Sat 80 80 S 2 0 1125 0 Blue 0
8 AM Sat 82 82 SE 2 0 1125 0 Blue 0
9 AM Sat 84 85 E 2 0 1125 0 Blue 0
10 AM Sat 87 90 E 2 2676 2470 1345 Blue 1
11 AM Sat 90 94 NE 2 3088 2924 1799 Blue 5
12 Noon Sat 93 97 NE 2 5297 3085 1960 Blue 8
1 PM Sat 96 100 N 2 6226 5257 4132 Blue 11
2 PM Sat 98 102 N 3 7579 5874 4749 Blue 13
3 PM Sat 100 103 NW 3 8226 6179 5054 Blue 14
4 PM Sat 101 102 NW 3 7579 5874 4749 Blue 13
5 PM Sat 101 101 W 5 6898 5567 4442 Blue 12
6 PM Sat 101 101 W 5 6898 5567 4442 Blue 12
7 PM Sat 100 100 W 5 6226 5257 4132 Blue 11
8 PM Sat 98 98 W 5 5609 3160 2035 Blue 9
9 PM Sat 96 96 W 5 3479 3031 1906 Blue 7
10 PM Sat 93 93 SW 3 3034 2661 1536 Blue 4
11 PM Sat 90 90 SW 3 2676 2470 1345 Blue 1
12 Midnight Sun 88 88 SW 3 0 1125 0 Blue 0
1 AM Sun 86 86 SW 3 0 1125 0 Blue 0
2 AM Sun 85 85 SW 3 0 1125 0 Blue 0
3 AM Sun 84 84 S 2 0 1125 0 Blue 0
4 AM Sun 82 82 S 2 0 1125 0 Blue 0
5 AM Sun 80 80 S 2 0 1125 0 Blue 0
6 AM Sun 79 79 SE 2 0 1125 0 Blue 0
7 AM Sun 80 80 SE 2 0 1125 0 Blue 0
8 AM Sun 82 82 SE 3 0 1125 0 Blue 0
9 AM Sun 84 86 SE 3 0 1125 0 Blue 0
10 AM Sun 88 91 SE 3 2927 2470 1345 Blue 2
11 AM Sun 91 95 SE 5 3178 2978 1853 Blue 6
12 Noon Sun 95 100 SE 5 6226 5257 4132 Blue 11
1 PM Sun 97 102 SE 5 7579 5874 4749 Blue 13
2 PM Sun 99 103 S 5 8226 6179 5054 Blue 14
3 PM Sun 101 104 S 5 8805 6776 5651 Blue 15
4 PM Sun 102 103 SW 3 8226 6179 5054 Blue 14
5 PM Sun 102 102 SW 3 7579 5874 4749 Blue 13
6 PM Sun 102 102 W 3 7579 5874 4749 Blue 13
7 PM Sun 101 101 SW 3 6898 5567 4442 Blue 12
8 PM Sun 98 98 SW 3 5609 3160 2035 Blue 9
9 PM Sun 96 96 SW 3 3479 3031 1906 Blue 7
10 PM Sun 93 93 SW 3 3034 2661 1536 Blue 4
11 PM Sun 90 90 SW 3 2676 2470 1345 Blue 1
12 Midnight Mon 87 87 SW 3 0 1125 0 Blue 0
1 AM Mon 86 86 SW 3 0 1125 0 Blue 0
2 AM Mon 85 85 SW 3 0 1125 0 Blue 0
3 AM Mon 83 83 SW 3 0 1125 0 Blue 0
4 AM Mon 82 82 S 3 0 1125 0 Blue 0
5 AM Mon 80 80 S 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