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

Station:

KTUS

Date/Time:

1 DEC 2020

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)
5 AM Tue 44 44 SE 6 0 1125 0 Blue 0
6 AM Tue 43 43 SE 6 0 1125 0 Blue 0
7 AM Tue 42 42 SE 6 0 1125 0 Blue 0
8 AM Tue 43 43 SE 6 0 1125 0 Blue 0
9 AM Tue 50 50 SE 5 0 1125 0 Blue 0
10 AM Tue 57 58 SE 5 2747 2641 1516 Blue 7
11 AM Tue 62 64 NE 3 2997 2849 1724 Blue 13
12 Noon Tue 66 69 N 3 3772 3181 2056 Blue 18
1 PM Tue 68 71 NW 3 3973 3372 2247 Blue 20
2 PM Tue 71 73 W 5 4418 3863 2738 Blue 22
3 PM Tue 71 72 W 6 4104 3763 2638 Blue 21
4 PM Tue 72 72 W 6 4104 3763 2638 Blue 21
5 PM Tue 68 68 W 3 3379 3086 1961 Blue 17
6 PM Tue 64 64 S 5 2997 2849 1724 Blue 13
7 PM Tue 60 60 S 6 2816 2711 1586 Blue 9
8 PM Tue 57 57 SE 6 2713 2603 1478 Blue 6
9 PM Tue 55 55 E 6 2642 2528 1403 Blue 5
10 PM Tue 54 54 SE 7 2605 2491 1366 Blue 4
11 PM Tue 51 51 SE 8 2492 2470 1345 Blue 1
12 Midnight Wed 50 50 SE 8 0 1125 0 Blue 0
1 AM Wed 49 49 E 8 0 1125 0 Blue 0
2 AM Wed 47 47 E 8 0 1125 0 Blue 0
3 AM Wed 46 46 E 8 0 1125 0 Blue 0
4 AM Wed 45 45 E 7 0 1125 0 Blue 0
5 AM Wed 44 44 E 7 0 1125 0 Blue 0
6 AM Wed 42 42 E 3 0 1125 0 Blue 0
7 AM Wed 40 40 E 3 0 1125 0 Blue 0
8 AM Wed 41 41 E 8 0 1125 0 Blue 0
9 AM Wed 49 49 E 3 0 1125 0 Blue 0
10 AM Wed 55 56 E 6 2679 2565 1440 Blue 5
11 AM Wed 60 62 E 10 2885 2780 1655 Blue 11
12 Noon Wed 64 67 E 9 3284 2991 1866 Blue 16
1 PM Wed 67 69 NE 7 3772 3181 2056 Blue 18
2 PM Wed 68 70 NE 5 3873 3277 2152 Blue 19
3 PM Wed 68 69 NE 3 3772 3181 2056 Blue 18
4 PM Wed 67 67 N 3 3284 2991 1866 Blue 16
5 PM Wed 65 65 N 5 3093 2883 1758 Blue 14
6 PM Wed 62 62 N 6 2885 2780 1655 Blue 11
7 PM Wed 58 58 N 7 2747 2641 1516 Blue 7
8 PM Wed 55 55 N 8 2642 2528 1403 Blue 5
9 PM Wed 53 53 N 9 2567 2470 1345 Blue 3
10 PM Wed 51 51 NE 10 2492 2470 1345 Blue 1
11 PM Wed 50 50 NE 10 0 1125 0 Blue 0
12 Midnight Thu 49 49 NE 10 0 1125 0 Blue 0
1 AM Thu 48 48 NE 9 0 1125 0 Blue 0
2 AM Thu 47 47 NE 9 0 1125 0 Blue 0
3 AM Thu 46 46 NE 9 0 1125 0 Blue 0
4 AM Thu 45 45 NE 8 0 1125 0 Blue 0
5 AM Thu 44 44 NE 8 0 1125 0 Blue 0
6 AM Thu 43 43 NE 8 0 1125 0 Blue 0
7 AM Thu 42 42 NE 8 0 1125 0 Blue 0
8 AM Thu 43 43 NE 9 0 1125 0 Blue 0
9 AM Thu 48 48 NE 12 0 1125 0 Blue 0
10 AM Thu 54 55 E 14 2642 2528 1403 Blue 5
11 AM Thu 59 61 E 15 2851 2746 1621 Blue 10
12 Noon Thu 62 65 E 16 3093 2883 1758 Blue 14
1 PM Thu 63 65 NE 16 3093 2883 1758 Blue 14
2 PM Thu 64 66 NE 15 3188 2918 1793 Blue 15
3 PM Thu 65 66 NE 14 3188 2918 1793 Blue 15
4 PM Thu 64 64 NE 12 2997 2849 1724 Blue 13
5 PM Thu 63 63 NE 9 2920 2814 1689 Blue 12
6 PM Thu 60 60 NE 8 2816 2711 1586 Blue 9
7 PM Thu 57 57 NE 8 2713 2603 1478 Blue 6
8 PM Thu 54 54 NE 8 2605 2491 1366 Blue 4
9 PM Thu 52 52 NE 8 2530 2470 1345 Blue 2
10 PM Thu 50 50 NE 8 0 1125 0 Blue 0
11 PM Thu 49 49 NE 8 0 1125 0 Blue 0
12 Midnight Fri 48 48 NE 8 0 1125 0 Blue 0
1 AM Fri 46 46 NE 7 0 1125 0 Blue 0
2 AM Fri 45 45 NE 7 0 1125 0 Blue 0
3 AM Fri 44 44 NE 7 0 1125 0 Blue 0
4 AM Fri 43 43 NE 7 0 1125 0 Blue 0
5 AM Fri 42 42 NE 7 0 1125 0 Blue 0
6 AM Fri 41 41 NE 7 0 1125 0 Blue 0
7 AM Fri 41 41 NE 6 0 1125 0 Blue 0
8 AM Fri 42 42 NE 6 0 1125 0 Blue 0
9 AM Fri 47 47 NE 6 0 1125 0 Blue 0
10 AM Fri 53 54 E 6 2605 2491 1366 Blue 4
11 AM Fri 58 60 E 6 2816 2711 1586 Blue 9
12 Noon Fri 61 63 E 6 2920 2814 1689 Blue 12
1 PM Fri 63 65 E 6 3093 2883 1758 Blue 14
2 PM Fri 64 66 E 6 3188 2918 1793 Blue 15
3 PM Fri 64 65 E 5 3093 2883 1758 Blue 14
4 PM Fri 64 64 E 5 2997 2849 1724 Blue 13
5 PM Fri 62 62 E 3 2885 2780 1655 Blue 11
6 PM Fri 59 59 E 2 2782 2677 1552 Blue 8
7 PM Fri 56 56 NE 2 2679 2565 1440 Blue 5
8 PM Fri 53 53 NE 2 2567 2470 1345 Blue 3
9 PM Fri 51 51 NE 2 2492 2470 1345 Blue 1
10 PM Fri 49 49 E 3 0 1125 0 Blue 0
11 PM Fri 48 48 E 3 0 1125 0 Blue 0
12 Midnight Sat 47 47 E 3 0 1125 0 Blue 0
1 AM Sat 46 46 E 5 0 1125 0 Blue 0
2 AM Sat 45 45 E 5 0 1125 0 Blue 0
3 AM Sat 44 44 E 5 0 1125 0 Blue 0
4 AM Sat 44 44 E 5 0 1125 0 Blue 0
5 AM Sat 43 43 E 5 0 1125 0 Blue 0
6 AM Sat 42 42 E 5 0 1125 0 Blue 0
7 AM Sat 41 41 E 5 0 1125 0 Blue 0
8 AM Sat 42 42 E 5 0 1125 0 Blue 0
9 AM Sat 47 47 E 5 0 1125 0 Blue 0
10 AM Sat 53 54 E 6 2605 2491 1366 Blue 4
11 AM Sat 59 61 E 6 2851 2746 1621 Blue 10
12 Noon Sat 63 65 E 6 3093 2883 1758 Blue 14
1 PM Sat 66 68 E 6 3379 3086 1961 Blue 17
2 PM Sat 67 69 E 6 3772 3181 2056 Blue 18
3 PM Sat 67 68 E 5 3379 3086 1961 Blue 17
4 PM Sat 66 66 E 5 3188 2918 1793 Blue 15
5 PM Sat 64 64 NE 3 2997 2849 1724 Blue 13
6 PM Sat 61 61 NE 2 2851 2746 1621 Blue 10
7 PM Sat 58 58 E 2 2747 2641 1516 Blue 7
8 PM Sat 55 55 E 2 2642 2528 1403 Blue 5
9 PM Sat 53 53 E 3 2567 2470 1345 Blue 3
10 PM Sat 51 51 NE 3 2492 2470 1345 Blue 1
11 PM Sat 50 50 NE 5 0 1125 0 Blue 0
12 Midnight Sun 49 49 NE 5 0 1125 0 Blue 0
1 AM Sun 49 49 NE 5 0 1125 0 Blue 0
2 AM Sun 48 48 NE 5 0 1125 0 Blue 0
3 AM Sun 47 47 NE 5 0 1125 0 Blue 0
4 AM Sun 46 46 NE 5 0 1125 0 Blue 0
5 AM Sun 45 45 NE 5 0 1125 0 Blue 0
6 AM Sun 44 44 NE 5 0 1125 0 Blue 0
7 AM Sun 43 43 E 5 0 1125 0 Blue 0
8 AM Sun 44 44 E 5 0 1125 0 Blue 0
9 AM Sun 48 48 E 5 0 1125 0 Blue 0
10 AM Sun 54 55 E 6 2642 2528 1403 Blue 5
11 AM Sun 59 61 E 6 2851 2746 1621 Blue 10
12 Noon Sun 63 65 E 6 3093 2883 1758 Blue 14
1 PM Sun 66 68 E 6 3379 3086 1961 Blue 17
2 PM Sun 67 69 E 6 3772 3181 2056 Blue 18
3 PM Sun 67 68 E 5 3379 3086 1961 Blue 17
4 PM Sun 67 67 E 5 3284 2991 1866 Blue 16
5 PM Sun 65 65 E 3 3093 2883 1758 Blue 14
6 PM Sun 63 63 E 3 2920 2814 1689 Blue 12
7 PM Sun 60 60 NE 3 2816 2711 1586 Blue 9
8 PM Sun 57 57 NE 3 2713 2603 1478 Blue 6
9 PM Sun 55 55 E 3 2642 2528 1403 Blue 5
10 PM Sun 53 53 E 5 2567 2470 1345 Blue 3
11 PM Sun 51 51 E 5 2492 2470 1345 Blue 1
12 Midnight Mon 50 50 E 5 0 1125 0 Blue 0
1 AM Mon 50 50 E 5 0 1125 0 Blue 0
2 AM Mon 49 49 E 5 0 1125 0 Blue 0
3 AM Mon 48 48 E 5 0 1125 0 Blue 0
4 AM Mon 46 46 E 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