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

Station:

KTUS

Date/Time:

26 MAR 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 58 58 S 1 0 1125 0 Blue 0
7 AM Tue 58 58 NE 1 0 1125 0 Blue 0
8 AM Tue 57 57 NE 2 0 1125 0 Blue 0
9 AM Tue 63 64 E 1 0 1125 0 Blue 0
10 AM Tue 69 71 E 2 2897 2746 1621 Blue 7
11 AM Tue 75 78 E 2 3214 3010 1885 Blue 14
12 Noon Tue 80 83 NE 2 4204 3510 2385 Blue 19
1 PM Tue 83 86 NW 2 4809 4141 3016 Blue 22
2 PM Tue 85 87 W 2 5181 4493 3368 Blue 23
3 PM Tue 87 88 W 2 5656 4562 3437 Blue 23
4 PM Tue 88 89 W 3 6120 4774 3649 Blue 24
5 PM Tue 88 88 W 3 5656 4562 3437 Blue 23
6 PM Tue 87 87 W 5 5181 4493 3368 Blue 23
7 PM Tue 86 86 W 3 4809 4141 3016 Blue 22
8 PM Tue 81 81 W 2 3675 3204 2079 Blue 17
9 PM Tue 77 77 W 2 3069 2981 1856 Blue 13
10 PM Tue 73 73 W 2 2954 2866 1741 Blue 9
11 PM Tue 71 71 SW 2 2897 2746 1621 Blue 7
12 Midnight Wed 69 69 SW 2 2815 2614 1489 Blue 5
1 AM Wed 68 68 SW 2 2749 2536 1411 Blue 4
2 AM Wed 66 66 SW 2 2617 2470 1345 Blue 2
3 AM Wed 65 65 SW 2 2540 2470 1345 Blue 1
4 AM Wed 63 63 SW 2 0 1125 0 Blue 0
5 AM Wed 62 62 E 2 0 1125 0 Blue 0
6 AM Wed 61 61 SE 2 0 1125 0 Blue 0
7 AM Wed 61 61 SE 2 0 1125 0 Blue 0
8 AM Wed 60 60 SE 2 0 1125 0 Blue 0
9 AM Wed 65 66 SE 1 2617 2470 1345 Blue 2
10 AM Wed 71 74 SE 2 2983 2895 1770 Blue 10
11 AM Wed 76 77 SW 2 3069 2981 1856 Blue 13
12 Noon Wed 80 80 W 2 3522 3067 1942 Blue 16
1 PM Wed 83 83 W 2 4204 3510 2385 Blue 19
2 PM Wed 85 85 W 3 4569 3816 2691 Blue 21
3 PM Wed 86 86 W 3 4809 4141 3016 Blue 22
4 PM Wed 87 87 W 5 5181 4493 3368 Blue 23
5 PM Wed 86 86 W 6 4809 4141 3016 Blue 22
6 PM Wed 85 85 W 6 4569 3816 2691 Blue 21
7 PM Wed 82 82 W 5 3829 3357 2232 Blue 18
8 PM Wed 79 79 W 3 3368 3038 1913 Blue 15
9 PM Wed 75 75 W 2 3011 2924 1799 Blue 11
10 PM Wed 72 72 W 2 2925 2812 1687 Blue 8
11 PM Wed 70 70 W 3 2868 2680 1555 Blue 6
12 Midnight Thu 68 68 W 3 2749 2536 1411 Blue 4
1 AM Thu 66 66 W 3 2617 2470 1345 Blue 2
2 AM Thu 65 65 SW 3 2540 2470 1345 Blue 1
3 AM Thu 63 63 SW 3 0 1125 0 Blue 0
4 AM Thu 61 61 SW 3 0 1125 0 Blue 0
5 AM Thu 59 59 SW 3 0 1125 0 Blue 0
6 AM Thu 58 58 SW 3 0 1125 0 Blue 0
7 AM Thu 58 58 SW 3 0 1125 0 Blue 0
8 AM Thu 60 61 SW 2 0 1125 0 Blue 0
9 AM Thu 63 65 SW 2 2540 2470 1345 Blue 1
10 AM Thu 67 71 SW 3 2897 2746 1621 Blue 7
11 AM Thu 72 78 W 5 3214 3010 1885 Blue 14
12 Noon Thu 77 84 W 6 4500 3663 2538 Blue 20
1 PM Thu 80 87 W 7 5181 4493 3368 Blue 23
2 PM Thu 82 88 W 7 5656 4562 3437 Blue 23
3 PM Thu 83 87 W 8 5181 4493 3368 Blue 23
4 PM Thu 84 86 W 9 4809 4141 3016 Blue 22
5 PM Thu 84 85 W 10 4569 3816 2691 Blue 21
6 PM Thu 83 83 W 10 4204 3510 2385 Blue 19
7 PM Thu 80 80 W 9 3522 3067 1942 Blue 16
8 PM Thu 77 77 W 7 3069 2981 1856 Blue 13
9 PM Thu 73 73 W 6 2954 2866 1741 Blue 9
10 PM Thu 70 70 W 6 2868 2680 1555 Blue 6
11 PM Thu 67 67 W 6 2683 2470 1345 Blue 3
12 Midnight Fri 65 65 W 6 2540 2470 1345 Blue 1
1 AM Fri 63 63 W 5 0 1125 0 Blue 0
2 AM Fri 61 61 W 5 0 1125 0 Blue 0
3 AM Fri 59 59 W 3 0 1125 0 Blue 0
4 AM Fri 57 57 W 3 0 1125 0 Blue 0
5 AM Fri 56 56 W 2 0 1125 0 Blue 0
6 AM Fri 55 55 W 2 0 1125 0 Blue 0
7 AM Fri 55 55 W 2 0 1125 0 Blue 0
8 AM Fri 56 57 W 2 0 1125 0 Blue 0
9 AM Fri 59 61 SW 2 0 1125 0 Blue 0
10 AM Fri 64 68 W 3 2749 2536 1411 Blue 4
11 AM Fri 69 75 W 3 3011 2924 1799 Blue 11
12 Noon Fri 74 80 W 5 3522 3067 1942 Blue 16
1 PM Fri 77 84 W 5 4500 3663 2538 Blue 20
2 PM Fri 80 86 W 6 4809 4141 3016 Blue 22
3 PM Fri 81 85 W 6 4569 3816 2691 Blue 21
4 PM Fri 82 84 W 7 4500 3663 2538 Blue 20
5 PM Fri 83 84 W 8 4500 3663 2538 Blue 20
6 PM Fri 82 82 W 8 3829 3357 2232 Blue 18
7 PM Fri 79 79 W 8 3368 3038 1913 Blue 15
8 PM Fri 76 76 W 7 3040 2952 1827 Blue 12
9 PM Fri 72 72 W 6 2925 2812 1687 Blue 8
10 PM Fri 69 69 W 6 2815 2614 1489 Blue 5
11 PM Fri 67 67 W 6 2683 2470 1345 Blue 3
12 Midnight Sat 65 65 W 6 2540 2470 1345 Blue 1
1 AM Sat 63 63 W 5 0 1125 0 Blue 0
2 AM Sat 62 62 NW 5 0 1125 0 Blue 0
3 AM Sat 60 60 NW 3 0 1125 0 Blue 0
4 AM Sat 58 58 NW 3 0 1125 0 Blue 0
5 AM Sat 56 56 NW 2 0 1125 0 Blue 0
6 AM Sat 55 55 NW 2 0 1125 0 Blue 0
7 AM Sat 55 55 NW 2 0 1125 0 Blue 0
8 AM Sat 56 56 N 2 0 1125 0 Blue 0
9 AM Sat 59 61 N 2 0 1125 0 Blue 0
10 AM Sat 64 67 N 3 2683 2470 1345 Blue 3
11 AM Sat 70 75 N 5 3011 2924 1799 Blue 11
12 Noon Sat 75 81 N 6 3675 3204 2079 Blue 17
1 PM Sat 78 84 N 6 4500 3663 2538 Blue 20
2 PM Sat 81 86 N 6 4809 4141 3016 Blue 22
3 PM Sat 82 86 N 6 4809 4141 3016 Blue 22
4 PM Sat 83 85 N 7 4569 3816 2691 Blue 21
5 PM Sat 83 84 NW 8 4500 3663 2538 Blue 20
6 PM Sat 82 82 NW 9 3829 3357 2232 Blue 18
7 PM Sat 79 79 NW 8 3368 3038 1913 Blue 15
8 PM Sat 76 76 NW 7 3040 2952 1827 Blue 12
9 PM Sat 72 72 W 6 2925 2812 1687 Blue 8
10 PM Sat 69 69 W 6 2815 2614 1489 Blue 5
11 PM Sat 67 67 W 6 2683 2470 1345 Blue 3
12 Midnight Sun 65 65 W 6 2540 2470 1345 Blue 1
1 AM Sun 63 63 NW 6 0 1125 0 Blue 0
2 AM Sun 61 61 NW 6 0 1125 0 Blue 0
3 AM Sun 60 60 N 6 0 1125 0 Blue 0
4 AM Sun 58 58 N 6 0 1125 0 Blue 0
5 AM Sun 57 57 N 5 0 1125 0 Blue 0
6 AM Sun 56 56 NE 5 0 1125 0 Blue 0
7 AM Sun 56 56 NE 5 0 1125 0 Blue 0
8 AM Sun 57 58 NE 5 0 1125 0 Blue 0
9 AM Sun 60 62 NE 6 0 1125 0 Blue 0
10 AM Sun 65 69 NE 7 2815 2614 1489 Blue 5
11 AM Sun 70 76 NE 8 3040 2952 1827 Blue 12
12 Noon Sun 75 81 NE 9 3675 3204 2079 Blue 17
1 PM Sun 78 84 NE 9 4500 3663 2538 Blue 20
2 PM Sun 81 87 NE 8 5181 4493 3368 Blue 23
3 PM Sun 82 86 NE 7 4809 4141 3016 Blue 22
4 PM Sun 83 85 NE 7 4569 3816 2691 Blue 21
5 PM Sun 83 84 N 7 4500 3663 2538 Blue 20
6 PM Sun 83 83 N 7 4204 3510 2385 Blue 19
7 PM Sun 80 80 N 6 3522 3067 1942 Blue 16
8 PM Sun 76 76 NE 5 3040 2952 1827 Blue 12
9 PM Sun 72 72 NE 3 2925 2812 1687 Blue 8
10 PM Sun 69 69 NE 3 2815 2614 1489 Blue 5
11 PM Sun 67 67 N 5 2683 2470 1345 Blue 3
12 Midnight Mon 65 65 N 5 2540 2470 1345 Blue 1
1 AM Mon 63 63 N 5 0 1125 0 Blue 0
2 AM Mon 61 61 N 5 0 1125 0 Blue 0
3 AM Mon 59 59 NE 5 0 1125 0 Blue 0
4 AM Mon 57 57 NE 5 0 1125 0 Blue 0
5 AM Mon 56 56 NE 5 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