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

Station:

KTUS

Date/Time:

26 MAY 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 Sun 61 61 SE 8 0 1125 0 Blue 0
7 AM Sun 60 61 SE 10 0 1125 0 Blue 0
8 AM Sun 64 66 S 13 0 1125 0 Blue 0
9 AM Sun 69 73 S 14 2498 2470 1345 Blue 1
10 AM Sun 73 79 S 15 3074 2628 1503 Blue 7
11 AM Sun 75 83 S 16 4651 3542 2417 Blue 10
12 Noon Sun 77 86 S 16 8211 4303 3178 Blue 13
1 PM Sun 79 88 SW 16 8380 7519 6394 Blue 15
2 PM Sun 81 89 SW 16 8626 8083 6958 Blue 16
3 PM Sun 82 88 SW 16 8380 7519 6394 Blue 15
4 PM Sun 83 87 SW 17 8299 6656 5531 Blue 14
5 PM Sun 83 85 SW 17 7640 4043 2918 Blue 12
6 PM Sun 83 83 SW 18 4651 3542 2417 Blue 10
7 PM Sun 82 82 SW 17 4066 3019 1894 Blue 10
8 PM Sun 80 80 SW 16 3561 2672 1547 Blue 8
9 PM Sun 77 77 SW 16 2674 2540 1415 Blue 5
10 PM Sun 74 74 SW 16 2542 2470 1345 Blue 2
11 PM Sun 72 72 SW 16 0 1125 0 Blue 0
12 Midnight Mon 70 70 SW 15 0 1125 0 Blue 0
1 AM Mon 68 68 SW 14 0 1125 0 Blue 0
2 AM Mon 67 67 SW 12 0 1125 0 Blue 0
3 AM Mon 64 64 SW 10 0 1125 0 Blue 0
4 AM Mon 63 63 SW 12 0 1125 0 Blue 0
5 AM Mon 61 61 SW 13 0 1125 0 Blue 0
6 AM Mon 61 61 SW 14 0 1125 0 Blue 0
7 AM Mon 59 59 SW 14 0 1125 0 Blue 0
8 AM Mon 61 62 SW 13 0 1125 0 Blue 0
9 AM Mon 64 67 SW 13 0 1125 0 Blue 0
10 AM Mon 67 72 SW 13 0 1125 0 Blue 0
11 AM Mon 69 76 SW 13 2630 2496 1371 Blue 4
12 Noon Mon 71 80 SW 13 3561 2672 1547 Blue 8
1 PM Mon 73 82 SW 13 4066 3019 1894 Blue 10
2 PM Mon 75 83 W 14 4651 3542 2417 Blue 10
3 PM Mon 76 82 W 14 4066 3019 1894 Blue 10
4 PM Mon 77 81 W 14 3814 2715 1590 Blue 9
5 PM Mon 78 80 W 14 3561 2672 1547 Blue 8
6 PM Mon 78 78 W 13 2718 2584 1459 Blue 6
7 PM Mon 77 77 W 10 2674 2540 1415 Blue 5
8 PM Mon 74 74 W 9 2542 2470 1345 Blue 2
9 PM Mon 72 72 W 7 0 1125 0 Blue 0
10 PM Mon 70 70 SW 7 0 1125 0 Blue 0
11 PM Mon 68 68 SW 7 0 1125 0 Blue 0
12 Midnight Tue 66 66 SW 8 0 1125 0 Blue 0
1 AM Tue 64 64 SW 7 0 1125 0 Blue 0
2 AM Tue 63 63 SW 6 0 1125 0 Blue 0
3 AM Tue 61 61 SW 6 0 1125 0 Blue 0
4 AM Tue 59 59 SW 5 0 1125 0 Blue 0
5 AM Tue 57 57 SW 3 0 1125 0 Blue 0
6 AM Tue 57 57 SW 3 0 1125 0 Blue 0
7 AM Tue 60 61 SW 3 0 1125 0 Blue 0
8 AM Tue 64 66 SW 2 0 1125 0 Blue 0
9 AM Tue 69 73 SW 2 2498 2470 1345 Blue 1
10 AM Tue 72 78 SW 2 2718 2584 1459 Blue 6
11 AM Tue 75 83 SW 3 4651 3542 2417 Blue 10
12 Noon Tue 78 87 SW 3 8299 6656 5531 Blue 14
1 PM Tue 80 89 SW 3 8626 8083 6958 Blue 16
2 PM Tue 82 90 SW 5 8900 8280 7155 Blue 17
3 PM Tue 84 90 W 6 8900 8280 7155 Blue 17
4 PM Tue 86 90 W 7 8900 8280 7155 Blue 17
5 PM Tue 86 88 W 7 8380 7519 6394 Blue 15
6 PM Tue 86 86 W 8 8211 4303 3178 Blue 13
7 PM Tue 84 84 W 8 6975 3793 2668 Blue 11
8 PM Tue 81 81 W 8 3814 2715 1590 Blue 9
9 PM Tue 78 78 W 7 2718 2584 1459 Blue 6
10 PM Tue 76 76 W 7 2630 2496 1371 Blue 4
11 PM Tue 74 74 W 7 2542 2470 1345 Blue 2
12 Midnight Wed 72 72 W 6 0 1125 0 Blue 0
1 AM Wed 70 70 W 6 0 1125 0 Blue 0
2 AM Wed 69 69 SW 6 0 1125 0 Blue 0
3 AM Wed 67 67 SW 6 0 1125 0 Blue 0
4 AM Wed 65 65 SW 6 0 1125 0 Blue 0
5 AM Wed 63 63 SW 6 0 1125 0 Blue 0
6 AM Wed 63 63 SW 6 0 1125 0 Blue 0
7 AM Wed 65 66 SW 6 0 1125 0 Blue 0
8 AM Wed 70 72 SW 5 0 1125 0 Blue 0
9 AM Wed 74 78 SW 5 2718 2584 1459 Blue 6
10 AM Wed 78 84 SW 5 6975 3793 2668 Blue 11
11 AM Wed 82 90 SW 5 8900 8280 7155 Blue 17
12 Noon Wed 85 94 SW 5 9844 9026 7901 Blue 21
1 PM Wed 88 97 SW 6 12859 9795 8670 Blue 24
2 PM Wed 90 98 W 6 13207 12016 10891 Blue 25
3 PM Wed 91 97 W 7 12859 9795 8670 Blue 24
4 PM Wed 92 96 W 7 12506 9627 8502 Blue 23
5 PM Wed 93 95 W 8 12148 9358 8233 Blue 22
6 PM Wed 92 92 W 8 9459 8554 7429 Blue 19
7 PM Wed 90 90 W 8 8900 8280 7155 Blue 17
8 PM Wed 87 87 W 9 8299 6656 5531 Blue 14
9 PM Wed 84 84 W 9 6975 3793 2668 Blue 11
10 PM Wed 82 82 W 9 4066 3019 1894 Blue 10
11 PM Wed 79 79 SW 9 3074 2628 1503 Blue 7
12 Midnight Thu 77 77 SW 8 2674 2540 1415 Blue 5
1 AM Thu 75 75 SW 8 2586 2470 1345 Blue 3
2 AM Thu 73 73 SW 7 2498 2470 1345 Blue 1
3 AM Thu 71 71 SW 6 0 1125 0 Blue 0
4 AM Thu 69 69 SW 5 0 1125 0 Blue 0
5 AM Thu 67 67 SW 3 0 1125 0 Blue 0
6 AM Thu 67 67 SW 3 0 1125 0 Blue 0
7 AM Thu 69 70 SW 2 0 1125 0 Blue 0
8 AM Thu 74 76 SW 2 2630 2496 1371 Blue 4
9 AM Thu 78 82 SW 2 4066 3019 1894 Blue 10
10 AM Thu 82 88 SW 2 8380 7519 6394 Blue 15
11 AM Thu 86 94 W 2 9844 9026 7901 Blue 21
12 Noon Thu 89 98 W 2 13207 12016 10891 Blue 25
1 PM Thu 91 100 W 2 15212 12722 11597 Blue 27
2 PM Thu 93 101 W 3 15871 13067 11942 Blue 28
3 PM Thu 94 100 W 5 15212 12722 11597 Blue 27
4 PM Thu 95 99 W 5 14010 12371 11246 Blue 26
5 PM Thu 96 98 W 6 13207 12016 10891 Blue 25
6 PM Thu 95 95 W 7 12148 9358 8233 Blue 22
7 PM Thu 93 93 W 7 9674 8845 7720 Blue 20
8 PM Thu 90 90 W 8 8900 8280 7155 Blue 17
9 PM Thu 87 87 W 8 8299 6656 5531 Blue 14
10 PM Thu 84 84 W 8 6975 3793 2668 Blue 11
11 PM Thu 82 82 W 8 4066 3019 1894 Blue 10
12 Midnight Fri 79 79 W 8 3074 2628 1503 Blue 7
1 AM Fri 76 76 SW 8 2630 2496 1371 Blue 4
2 AM Fri 74 74 SW 7 2542 2470 1345 Blue 2
3 AM Fri 72 72 SW 6 0 1125 0 Blue 0
4 AM Fri 70 70 SW 6 0 1125 0 Blue 0
5 AM Fri 68 68 SW 5 0 1125 0 Blue 0
6 AM Fri 68 68 SW 3 0 1125 0 Blue 0
7 AM Fri 70 71 SW 3 0 1125 0 Blue 0
8 AM Fri 74 76 SW 3 2630 2496 1371 Blue 4
9 AM Fri 78 82 SW 3 4066 3019 1894 Blue 10
10 AM Fri 82 88 SW 3 8380 7519 6394 Blue 15
11 AM Fri 86 94 SW 3 9844 9026 7901 Blue 21
12 Noon Fri 89 98 SW 5 13207 12016 10891 Blue 25
1 PM Fri 92 101 SW 5 15871 13067 11942 Blue 28
2 PM Fri 94 102 SW 6 16616 13447 12322 Blue 29
3 PM Fri 95 101 SW 7 15871 13067 11942 Blue 28
4 PM Fri 96 100 SW 7 15212 12722 11597 Blue 27
5 PM Fri 97 99 W 8 14010 12371 11246 Blue 26
6 PM Fri 96 96 W 9 12506 9627 8502 Blue 23
7 PM Fri 94 94 W 9 9844 9026 7901 Blue 21
8 PM Fri 90 90 SW 9 8900 8280 7155 Blue 17
9 PM Fri 87 87 SW 9 8299 6656 5531 Blue 14
10 PM Fri 84 84 SW 8 6975 3793 2668 Blue 11
11 PM Fri 82 82 SW 8 4066 3019 1894 Blue 10
12 Midnight Sat 79 79 SW 8 3074 2628 1503 Blue 7
1 AM Sat 76 76 SW 7 2630 2496 1371 Blue 4
2 AM Sat 74 74 SW 6 2542 2470 1345 Blue 2
3 AM Sat 72 72 S 6 0 1125 0 Blue 0
4 AM Sat 69 69 S 5 0 1125 0 Blue 0
5 AM Sat 67 67 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