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

Station:

KTUS

Date/Time:

N/A

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 Thu 46 46 E 5 N/A N/A N/A N/A N/A
6 AM Thu 44 44 E 5 N/A N/A N/A N/A N/A
7 AM Thu 47 47 E 5 N/A N/A N/A N/A N/A
8 AM Thu 46 46 E 5 N/A N/A N/A N/A N/A
9 AM Thu 51 51 E 6 N/A N/A N/A N/A N/A
10 AM Thu 56 57 E 6 N/A N/A N/A N/A N/A
11 AM Thu 60 62 E 6 N/A N/A N/A N/A N/A
12 Noon Thu 62 64 SE 6 N/A N/A N/A N/A N/A
1 PM Thu 65 67 S 6 N/A N/A N/A N/A N/A
2 PM Thu 67 68 SW 6 N/A N/A N/A N/A N/A
3 PM Thu 69 69 W 6 N/A N/A N/A N/A N/A
4 PM Thu 69 69 W 6 N/A N/A N/A N/A N/A
5 PM Thu 69 69 W 6 N/A N/A N/A N/A N/A
6 PM Thu 65 65 W 6 N/A N/A N/A N/A N/A
7 PM Thu 62 62 W 6 N/A N/A N/A N/A N/A
8 PM Thu 59 59 W 6 N/A N/A N/A N/A N/A
9 PM Thu 58 58 SW 6 N/A N/A N/A N/A N/A
10 PM Thu 56 56 SW 6 N/A N/A N/A N/A N/A
11 PM Thu 55 55 SW 6 N/A N/A N/A N/A N/A
12 Midnight Fri 54 54 SW 6 N/A N/A N/A N/A N/A
1 AM Fri 54 54 SW 7 N/A N/A N/A N/A N/A
2 AM Fri 53 53 SW 7 N/A N/A N/A N/A N/A
3 AM Fri 53 53 SW 7 N/A N/A N/A N/A N/A
4 AM Fri 52 52 SW 7 N/A N/A N/A N/A N/A
5 AM Fri 52 52 SW 7 N/A N/A N/A N/A N/A
6 AM Fri 51 51 SW 7 N/A N/A N/A N/A N/A
7 AM Fri 51 51 SW 7 N/A N/A N/A N/A N/A
8 AM Fri 50 50 W 7 N/A N/A N/A N/A N/A
9 AM Fri 53 53 W 7 N/A N/A N/A N/A N/A
10 AM Fri 56 57 W 8 N/A N/A N/A N/A N/A
11 AM Fri 60 62 W 8 N/A N/A N/A N/A N/A
12 Noon Fri 61 63 W 9 N/A N/A N/A N/A N/A
1 PM Fri 63 65 W 10 N/A N/A N/A N/A N/A
2 PM Fri 64 66 W 10 N/A N/A N/A N/A N/A
3 PM Fri 66 67 W 12 N/A N/A N/A N/A N/A
4 PM Fri 67 67 W 12 N/A N/A N/A N/A N/A
5 PM Fri 67 67 W 12 N/A N/A N/A N/A N/A
6 PM Fri 64 64 NW 12 N/A N/A N/A N/A N/A
7 PM Fri 60 60 NW 10 N/A N/A N/A N/A N/A
8 PM Fri 57 57 NW 9 N/A N/A N/A N/A N/A
9 PM Fri 54 54 N 8 N/A N/A N/A N/A N/A
10 PM Fri 52 52 N 7 N/A N/A N/A N/A N/A
11 PM Fri 51 51 N 6 N/A N/A N/A N/A N/A
12 Midnight Sat 50 50 N 6 N/A N/A N/A N/A N/A
1 AM Sat 48 48 N 6 N/A N/A N/A N/A N/A
2 AM Sat 47 47 NE 6 N/A N/A N/A N/A N/A
3 AM Sat 47 47 NE 6 N/A N/A N/A N/A N/A
4 AM Sat 46 46 NE 6 N/A N/A N/A N/A N/A
5 AM Sat 44 44 NE 6 N/A N/A N/A N/A N/A
6 AM Sat 42 42 NE 6 N/A N/A N/A N/A N/A
7 AM Sat 41 41 NE 7 N/A N/A N/A N/A N/A
8 AM Sat 42 42 NE 7 N/A N/A N/A N/A N/A
9 AM Sat 46 46 NE 8 N/A N/A N/A N/A N/A
10 AM Sat 52 53 NE 9 N/A N/A N/A N/A N/A
11 AM Sat 57 59 NE 9 N/A N/A N/A N/A N/A
12 Noon Sat 61 64 NE 9 N/A N/A N/A N/A N/A
1 PM Sat 64 67 NE 8 N/A N/A N/A N/A N/A
2 PM Sat 65 67 NE 7 N/A N/A N/A N/A N/A
3 PM Sat 67 68 NE 6 N/A N/A N/A N/A N/A
4 PM Sat 68 68 NE 6 N/A N/A N/A N/A N/A
5 PM Sat 67 67 NE 6 N/A N/A N/A N/A N/A
6 PM Sat 65 65 NE 6 N/A N/A N/A N/A N/A
7 PM Sat 61 61 NE 6 N/A N/A N/A N/A N/A
8 PM Sat 57 57 NE 5 N/A N/A N/A N/A N/A
9 PM Sat 54 54 NE 5 N/A N/A N/A N/A N/A
10 PM Sat 52 52 NE 5 N/A N/A N/A N/A N/A
11 PM Sat 51 51 NE 5 N/A N/A N/A N/A N/A
12 Midnight Sun 50 50 NE 5 N/A N/A N/A N/A N/A
1 AM Sun 49 49 NE 5 N/A N/A N/A N/A N/A
2 AM Sun 48 48 NE 5 N/A N/A N/A N/A N/A
3 AM Sun 47 47 NE 5 N/A N/A N/A N/A N/A
4 AM Sun 46 46 NE 5 N/A N/A N/A N/A N/A
5 AM Sun 45 45 NE 5 N/A N/A N/A N/A N/A
6 AM Sun 44 44 NE 6 N/A N/A N/A N/A N/A
7 AM Sun 43 43 NE 6 N/A N/A N/A N/A N/A
8 AM Sun 45 45 NE 6 N/A N/A N/A N/A N/A
9 AM Sun 49 49 NE 7 N/A N/A N/A N/A N/A
10 AM Sun 55 55 NE 7 N/A N/A N/A N/A N/A
11 AM Sun 60 61 NE 7 N/A N/A N/A N/A N/A
12 Noon Sun 64 65 NE 6 N/A N/A N/A N/A N/A
1 PM Sun 67 68 NE 6 N/A N/A N/A N/A N/A
2 PM Sun 68 69 NE 5 N/A N/A N/A N/A N/A
3 PM Sun 70 70 NE 3 N/A N/A N/A N/A N/A
4 PM Sun 71 71 NE 3 N/A N/A N/A N/A N/A
5 PM Sun 70 70 NE 3 N/A N/A N/A N/A N/A
6 PM Sun 67 67 NE 3 N/A N/A N/A N/A N/A
7 PM Sun 63 63 N 3 N/A N/A N/A N/A N/A
8 PM Sun 59 59 NW 2 N/A N/A N/A N/A N/A
9 PM Sun 56 56 W 2 N/A N/A N/A N/A N/A
10 PM Sun 54 54 W 2 N/A N/A N/A N/A N/A
11 PM Sun 53 53 SW 2 N/A N/A N/A N/A N/A
12 Midnight Mon 51 51 SW 2 N/A N/A N/A N/A N/A
1 AM Mon 50 50 SW 2 N/A N/A N/A N/A N/A
2 AM Mon 49 49 SW 3 N/A N/A N/A N/A N/A
3 AM Mon 48 48 SW 3 N/A N/A N/A N/A N/A
4 AM Mon 47 47 SW 3 N/A N/A N/A N/A N/A
5 AM Mon 46 46 SW 3 N/A N/A N/A N/A N/A
6 AM Mon 44 44 SW 3 N/A N/A N/A N/A N/A
7 AM Mon 44 44 SW 3 N/A N/A N/A N/A N/A
8 AM Mon 45 45 SW 5 N/A N/A N/A N/A N/A
9 AM Mon 49 49 SW 6 N/A N/A N/A N/A N/A
10 AM Mon 56 57 W 7 N/A N/A N/A N/A N/A
11 AM Mon 61 63 W 8 N/A N/A N/A N/A N/A
12 Noon Mon 64 66 W 9 N/A N/A N/A N/A N/A
1 PM Mon 66 68 W 12 N/A N/A N/A N/A N/A
2 PM Mon 67 69 W 14 N/A N/A N/A N/A N/A
3 PM Mon 68 69 W 15 N/A N/A N/A N/A N/A
4 PM Mon 68 68 W 15 N/A N/A N/A N/A N/A
5 PM Mon 67 67 W 15 N/A N/A N/A N/A N/A
6 PM Mon 64 64 W 15 N/A N/A N/A N/A N/A
7 PM Mon 60 60 W 15 N/A N/A N/A N/A N/A
8 PM Mon 56 56 W 14 N/A N/A N/A N/A N/A
9 PM Mon 54 54 NW 14 N/A N/A N/A N/A N/A
10 PM Mon 52 52 NW 13 N/A N/A N/A N/A N/A
11 PM Mon 51 51 NW 12 N/A N/A N/A N/A N/A
12 Midnight Tue 49 49 NW 10 N/A N/A N/A N/A N/A
1 AM Tue 47 47 NW 9 N/A N/A N/A N/A N/A
2 AM Tue 46 46 NW 8 N/A N/A N/A N/A N/A
3 AM Tue 45 45 NW 7 N/A N/A N/A N/A N/A
4 AM Tue 44 44 NW 6 N/A N/A N/A N/A N/A
5 AM Tue 43 43 NW 6 N/A N/A N/A N/A N/A
6 AM Tue 41 41 NW 6 N/A N/A N/A N/A N/A
7 AM Tue 39 39 NW 6 N/A N/A N/A N/A N/A
8 AM Tue 40 40 N 6 N/A N/A N/A N/A N/A
9 AM Tue 44 44 N 7 N/A N/A N/A N/A N/A
10 AM Tue 50 51 NE 7 N/A N/A N/A N/A N/A
11 AM Tue 55 57 NE 7 N/A N/A N/A N/A N/A
12 Noon Tue 59 62 NE 7 N/A N/A N/A N/A N/A
1 PM Tue 60 63 NE 7 N/A N/A N/A N/A N/A
2 PM Tue 62 64 N 7 N/A N/A N/A N/A N/A
3 PM Tue 64 65 N 7 N/A N/A N/A N/A N/A
4 PM Tue 65 65 N 7 N/A N/A N/A N/A N/A
5 PM Tue 65 65 N 7 N/A N/A N/A N/A N/A
6 PM Tue 62 62 N 7 N/A N/A N/A N/A N/A
7 PM Tue 58 58 N 7 N/A N/A N/A N/A N/A
8 PM Tue 54 54 N 7 N/A N/A N/A N/A N/A
9 PM Tue 51 51 N 7 N/A N/A N/A N/A N/A
10 PM Tue 49 49 N 6 N/A N/A N/A N/A N/A
11 PM Tue 48 48 N 6 N/A N/A N/A N/A N/A
12 Midnight Wed 46 46 NE 6 N/A N/A N/A N/A N/A
1 AM Wed 45 45 NE 6 N/A N/A N/A N/A N/A
2 AM Wed 44 44 NE 6 N/A N/A N/A N/A N/A
3 AM Wed 43 43 NE 6 N/A N/A N/A N/A N/A
4 AM Wed 42 42 NE 6 N/A N/A N/A N/A N/A

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