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

Station:

KTUS

Date/Time:

2 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 Wed 43 43 E 5 0 1125 0 Blue 0
6 AM Wed 43 43 E 5 0 1125 0 Blue 0
7 AM Wed 42 42 E 5 0 1125 0 Blue 0
8 AM Wed 42 42 E 5 0 1125 0 Blue 0
9 AM Wed 50 50 E 7 2592 2505 1380 Blue 4
10 AM Wed 58 59 NE 8 3066 2868 1743 Blue 13
11 AM Wed 62 64 NE 10 3300 3156 2031 Blue 18
12 Noon Wed 65 67 NE 12 3598 3297 2172 Blue 21
1 PM Wed 67 69 NE 12 4066 3430 2305 Blue 23
2 PM Wed 69 71 NE 10 4938 3740 2615 Blue 25
3 PM Wed 69 70 NE 8 4529 3585 2460 Blue 24
4 PM Wed 68 68 NE 7 3754 3343 2218 Blue 22
5 PM Wed 66 66 NE 6 3443 3250 2125 Blue 20
6 PM Wed 63 63 NE 7 3253 3110 1985 Blue 17
7 PM Wed 59 59 NE 9 3066 2868 1743 Blue 13
8 PM Wed 58 58 NE 12 3008 2801 1676 Blue 12
9 PM Wed 56 56 NE 13 2872 2691 1566 Blue 10
10 PM Wed 53 53 N 13 2693 2591 1466 Blue 7
11 PM Wed 52 52 N 13 2655 2562 1437 Blue 6
12 Midnight Thu 51 51 NE 13 2621 2533 1408 Blue 5
1 AM Thu 51 51 NE 13 2621 2533 1408 Blue 5
2 AM Thu 51 51 NE 13 2621 2533 1408 Blue 5
3 AM Thu 50 50 NE 13 2592 2505 1380 Blue 4
4 AM Thu 49 49 NE 12 2563 2476 1351 Blue 3
5 AM Thu 48 48 NE 12 2535 2470 1345 Blue 2
6 AM Thu 46 46 NE 12 2477 2470 1345 Blue 0
7 AM Thu 45 45 NE 12 0 1125 0 Blue 0
8 AM Thu 46 46 NE 12 2477 2470 1345 Blue 0
9 AM Thu 52 52 NE 14 2655 2562 1437 Blue 6
10 AM Thu 57 58 NE 16 3008 2801 1676 Blue 12
11 AM Thu 60 62 NE 17 3206 3063 1938 Blue 16
12 Noon Thu 63 66 NE 17 3443 3250 2125 Blue 20
1 PM Thu 64 66 E 17 3443 3250 2125 Blue 20
2 PM Thu 65 67 E 15 3598 3297 2172 Blue 21
3 PM Thu 65 66 NE 12 3443 3250 2125 Blue 20
4 PM Thu 65 65 NE 7 3347 3203 2078 Blue 19
5 PM Thu 63 63 NE 3 3253 3110 1985 Blue 17
6 PM Thu 60 60 N 2 3113 2936 1811 Blue 14
7 PM Thu 57 57 N 2 2940 2733 1608 Blue 11
8 PM Thu 53 53 N 2 2693 2591 1466 Blue 7
9 PM Thu 50 50 N 2 2592 2505 1380 Blue 4
10 PM Thu 48 48 NE 3 2535 2470 1345 Blue 2
11 PM Thu 46 46 NE 3 2477 2470 1345 Blue 0
12 Midnight Fri 44 44 NE 3 0 1125 0 Blue 0
1 AM Fri 43 43 NE 3 0 1125 0 Blue 0
2 AM Fri 42 42 NE 3 0 1125 0 Blue 0
3 AM Fri 41 41 NE 3 0 1125 0 Blue 0
4 AM Fri 40 40 E 2 0 1125 0 Blue 0
5 AM Fri 39 39 E 2 0 1125 0 Blue 0
6 AM Fri 37 37 E 2 0 1125 0 Blue 0
7 AM Fri 37 37 E 2 0 1125 0 Blue 0
8 AM Fri 38 38 E 2 0 1125 0 Blue 0
9 AM Fri 43 43 E 3 0 1125 0 Blue 0
10 AM Fri 50 51 E 3 2621 2533 1408 Blue 5
11 AM Fri 57 59 E 5 3066 2868 1743 Blue 13
12 Noon Fri 61 64 E 5 3300 3156 2031 Blue 18
1 PM Fri 64 67 E 3 3598 3297 2172 Blue 21
2 PM Fri 65 67 NE 3 3598 3297 2172 Blue 21
3 PM Fri 66 67 NE 3 3598 3297 2172 Blue 21
4 PM Fri 66 66 NE 2 3443 3250 2125 Blue 20
5 PM Fri 64 64 N 2 3300 3156 2031 Blue 18
6 PM Fri 60 60 N 2 3113 2936 1811 Blue 14
7 PM Fri 56 56 NE 2 2872 2691 1566 Blue 10
8 PM Fri 52 52 NE 2 2655 2562 1437 Blue 6
9 PM Fri 50 50 NE 2 2592 2505 1380 Blue 4
10 PM Fri 48 48 NE 2 2535 2470 1345 Blue 2
11 PM Fri 47 47 NE 2 2506 2470 1345 Blue 1
12 Midnight Sat 46 46 NE 2 2477 2470 1345 Blue 0
1 AM Sat 45 45 E 3 0 1125 0 Blue 0
2 AM Sat 44 44 E 3 0 1125 0 Blue 0
3 AM Sat 43 43 E 3 0 1125 0 Blue 0
4 AM Sat 42 42 E 2 0 1125 0 Blue 0
5 AM Sat 41 41 E 2 0 1125 0 Blue 0
6 AM Sat 40 40 E 2 0 1125 0 Blue 0
7 AM Sat 39 39 E 3 0 1125 0 Blue 0
8 AM Sat 41 41 E 3 0 1125 0 Blue 0
9 AM Sat 47 47 E 3 2506 2470 1345 Blue 1
10 AM Sat 54 55 E 5 2805 2653 1528 Blue 9
11 AM Sat 61 63 E 5 3253 3110 1985 Blue 17
12 Noon Sat 65 67 E 5 3598 3297 2172 Blue 21
1 PM Sat 68 70 E 5 4529 3585 2460 Blue 24
2 PM Sat 69 71 NE 5 4938 3740 2615 Blue 25
3 PM Sat 70 71 NE 3 4938 3740 2615 Blue 25
4 PM Sat 69 69 NE 3 4066 3430 2305 Blue 23
5 PM Sat 67 67 NE 2 3598 3297 2172 Blue 21
6 PM Sat 64 64 NE 2 3300 3156 2031 Blue 18
7 PM Sat 60 60 N 2 3113 2936 1811 Blue 14
8 PM Sat 56 56 N 2 2872 2691 1566 Blue 10
9 PM Sat 53 53 NE 2 2693 2591 1466 Blue 7
10 PM Sat 51 51 NE 2 2621 2533 1408 Blue 5
11 PM Sat 50 50 E 2 2592 2505 1380 Blue 4
12 Midnight Sun 49 49 E 2 2563 2476 1351 Blue 3
1 AM Sun 48 48 E 3 2535 2470 1345 Blue 2
2 AM Sun 47 47 E 3 2506 2470 1345 Blue 1
3 AM Sun 46 46 E 3 2477 2470 1345 Blue 0
4 AM Sun 45 45 E 3 0 1125 0 Blue 0
5 AM Sun 44 44 E 3 0 1125 0 Blue 0
6 AM Sun 43 43 E 3 0 1125 0 Blue 0
7 AM Sun 42 42 E 3 0 1125 0 Blue 0
8 AM Sun 44 44 E 3 0 1125 0 Blue 0
9 AM Sun 49 49 E 3 2563 2476 1351 Blue 3
10 AM Sun 56 57 E 5 2940 2733 1608 Blue 11
11 AM Sun 62 64 E 5 3300 3156 2031 Blue 18
12 Noon Sun 66 68 E 5 3754 3343 2218 Blue 22
1 PM Sun 69 71 E 5 4938 3740 2615 Blue 25
2 PM Sun 70 72 E 5 5018 4020 2895 Blue 26
3 PM Sun 71 72 NE 3 5018 4020 2895 Blue 26
4 PM Sun 71 71 NE 3 4938 3740 2615 Blue 25
5 PM Sun 69 69 NE 2 4066 3430 2305 Blue 23
6 PM Sun 65 65 NE 2 3347 3203 2078 Blue 19
7 PM Sun 61 61 NE 2 3160 3004 1879 Blue 15
8 PM Sun 57 57 NE 2 2940 2733 1608 Blue 11
9 PM Sun 55 55 E 2 2805 2653 1528 Blue 9
10 PM Sun 53 53 E 3 2693 2591 1466 Blue 7
11 PM Sun 52 52 E 3 2655 2562 1437 Blue 6
12 Midnight Mon 51 51 E 3 2621 2533 1408 Blue 5
1 AM Mon 50 50 E 3 2592 2505 1380 Blue 4
2 AM Mon 49 49 E 3 2563 2476 1351 Blue 3
3 AM Mon 48 48 E 3 2535 2470 1345 Blue 2
4 AM Mon 46 46 E 3 2477 2470 1345 Blue 0
5 AM Mon 45 45 E 3 0 1125 0 Blue 0
6 AM Mon 43 43 E 3 0 1125 0 Blue 0
7 AM Mon 43 43 E 3 0 1125 0 Blue 0
8 AM Mon 44 44 E 3 0 1125 0 Blue 0
9 AM Mon 49 49 E 5 2563 2476 1351 Blue 3
10 AM Mon 56 57 E 5 2940 2733 1608 Blue 11
11 AM Mon 63 65 E 6 3347 3203 2078 Blue 19
12 Noon Mon 67 69 E 6 4066 3430 2305 Blue 23
1 PM Mon 70 72 E 6 5018 4020 2895 Blue 26
2 PM Mon 71 73 E 5 5099 4477 3352 Blue 27
3 PM Mon 72 73 E 3 5099 4477 3352 Blue 27
4 PM Mon 72 72 NE 3 5018 4020 2895 Blue 26
5 PM Mon 70 70 NE 2 4529 3585 2460 Blue 24
6 PM Mon 67 67 NE 2 3598 3297 2172 Blue 21
7 PM Mon 63 63 E 2 3253 3110 1985 Blue 17
8 PM Mon 59 59 E 2 3066 2868 1743 Blue 13
9 PM Mon 57 57 E 3 2940 2733 1608 Blue 11
10 PM Mon 55 55 E 3 2805 2653 1528 Blue 9
11 PM Mon 54 54 E 5 2737 2619 1494 Blue 8
12 Midnight Tue 53 53 E 5 2693 2591 1466 Blue 7
1 AM Tue 52 52 E 5 2655 2562 1437 Blue 6
2 AM Tue 51 51 E 5 2621 2533 1408 Blue 5
3 AM Tue 50 50 E 5 2592 2505 1380 Blue 4
4 AM Tue 49 49 E 5 2563 2476 1351 Blue 3

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 [email protected]