Detailed Predictions for: The Y
Launch Altitude (f): 4900
LZ Altitude (f): 3150
Sounding

Station:

 KTUS

Date/Time:

 3 SEP 2010

Temp/Wind data from:

NOAA Digital Forecast

Time
(Local)		 High
Temp
Puddle
Temp
Wind
 (mph)		 Thermal
Ceiling
(ft)		 Soaring
Ceiling
(ft)		 Above
Launch
(ft)		 Thermal
Type		 Thermal
Index
(F)
6 AM Fri 67 67 E 5 3789 4900 0 Blue 0
7 AM Fri 67 67 E 5 3789 4900 0 Blue 0
8 AM Fri 68 69 E 5 3789 4900 0 Blue 0
9 AM Fri 75 77 NE 6 3789 4900 0 Blue 0
10 AM Fri 81 85 NE 6 4875 4900 0 Blue 1
11 AM Fri 85 91 NE 6 16486 7235 2335 Blue 7
12 Noon Fri 88 93 SE 8 17604 8939 4039 Blue 9
1 PM Fri 91 96 SE 8 17800 17574 12674 Blue 12
2 PM Fri 93 98 SE 8 17963 17684 12784 Blue 14
3 PM Fri 93 96 S 9 17800 17574 12674 Blue 12
4 PM Fri 95 97 S 9 17882 17640 12740 Blue 13
5 PM Fri 95 96 S 9 17800 17574 12674 Blue 12
6 PM Fri 94 94 S 9 17660 16138 11238 Blue 10
7 PM Fri 92 92 S 9 17141 7938 3038 Blue 8
8 PM Fri 89 89 S 9 8015 5698 798 Blue 5
9 PM Fri 85 85 S 5 4875 4900 0 Blue 1
10 PM Fri 82 82 S 5 3789 4900 0 Blue 0
11 PM Fri 80 80 S 5 3789 4900 0 Blue 0
12 Midnight Sat 78 78 S 1 3789 4900 0 Blue 0
1 AM Sat 75 75 S 1 3789 4900 0 Blue 0
2 AM Sat 74 74 S 1 3789 4900 0 Blue 0
3 AM Sat 72 72 S 1 3789 4900 0 Blue 0
4 AM Sat 71 71 S 1 3789 4900 0 Blue 0
5 AM Sat 69 69 S 1 3789 4900 0 Blue 0
6 AM Sat 69 69 E 2 3789 4900 0 Blue 0
7 AM Sat 69 69 E 2 3789 4900 0 Blue 0
8 AM Sat 70 71 E 2 3789 4900 0 Blue 0
9 AM Sat 76 78 E 6 3789 4900 0 Blue 0
10 AM Sat 82 86 E 6 5733 4900 0 Blue 2
11 AM Sat 85 90 E 6 9086 6491 1591 Blue 6
12 Noon Sat 88 94 S 8 17660 16138 11238 Blue 10
1 PM Sat 91 97 S 8 17882 17640 12740 Blue 13
2 PM Sat 93 99 S 8 18151 17763 12863 Blue 15
3 PM Sat 93 97 S 13 17882 17640 12740 Blue 13
4 PM Sat 95 98 S 13 17963 17684 12784 Blue 14
5 PM Sat 95 96 S 13 17800 17574 12674 Blue 12
6 PM Sat 94 94 SW 13 17660 16138 11238 Blue 10
7 PM Sat 92 92 SW 13 17141 7938 3038 Blue 8
8 PM Sat 89 89 SW 13 8015 5698 798 Blue 5
9 PM Sat 86 86 S 7 5733 4900 0 Blue 2
10 PM Sat 83 83 S 7 3917 4900 0 Blue 0
11 PM Sat 81 81 S 7 3789 4900 0 Blue 0
12 Midnight Sun 80 80 S 3 3789 4900 0 Blue 0
1 AM Sun 78 78 S 3 3789 4900 0 Blue 0
2 AM Sun 77 77 S 3 3789 4900 0 Blue 0
3 AM Sun 75 75 SE 2 3789 4900 0 Blue 0
4 AM Sun 74 74 SE 2 3789 4900 0 Blue 0
5 AM Sun 72 72 SE 2 3789 4900 0 Blue 0
6 AM Sun 72 72 SE 2 3789 4900 0 Blue 0
7 AM Sun 72 72 SE 2 3789 4900 0 Blue 0
8 AM Sun 73 74 SE 2 3789 4900 0 Blue 0
9 AM Sun 78 80 S 8 3789 4900 0 Blue 0
10 AM Sun 82 86 S 8 5733 4900 0 Blue 2
11 AM Sun 85 90 S 8 9086 6491 1591 Blue 6
12 Noon Sun 87 94 SW 18 17660 16138 11238 Blue 10
1 PM Sun 90 97 SW 18 17882 17640 12740 Blue 13
2 PM Sun 91 97 SW 18 17882 17640 12740 Blue 13
3 PM Sun 92 97 SW 21 17882 17640 12740 Blue 13
4 PM Sun 93 96 SW 21 17800 17574 12674 Blue 12
5 PM Sun 93 94 SW 21 17660 16138 11238 Blue 10
6 PM Sun 92 92 SW 21 17141 7938 3038 Blue 8
7 PM Sun 89 89 SW 21 8015 5698 798 Blue 5
8 PM Sun 86 86 SW 21 5733 4900 0 Blue 2
9 PM Sun 82 82 SW 18 3789 4900 0 Blue 0
10 PM Sun 80 80 SW 18 3789 4900 0 Blue 0
11 PM Sun 77 77 SW 18 3789 4900 0 Blue 0
12 Midnight Mon 75 75 S 13 3789 4900 0 Blue 0
1 AM Mon 73 73 S 13 3789 4900 0 Blue 0
2 AM Mon 72 72 S 13 3789 4900 0 Blue 0
3 AM Mon 70 70 S 8 3789 4900 0 Blue 0
4 AM Mon 69 69 S 8 3789 4900 0 Blue 0
5 AM Mon 67 67 S 8 3789 4900 0 Blue 0
6 AM Mon 67 67 S 5 3789 4900 0 Blue 0
7 AM Mon 66 66 S 5 3789 4900 0 Blue 0
8 AM Mon 68 69 S 5 3789 4900 0 Blue 0
9 AM Mon 73 75 S 9 3789 4900 0 Blue 0
10 AM Mon 78 82 S 9 3789 4900 0 Blue 0
11 AM Mon 81 87 S 9 6542 4900 0 Blue 3
12 Noon Mon 84 91 S 9 16486 7235 2335 Blue 7
1 PM Mon 86 93 S 9 17604 8939 4039 Blue 9
2 PM Mon 88 94 S 9 17660 16138 11238 Blue 10
3 PM Mon 88 93 SW 13 17604 8939 4039 Blue 9
4 PM Mon 90 93 SW 13 17604 8939 4039 Blue 9
5 PM Mon 90 91 SW 13 16486 7235 2335 Blue 7
6 PM Mon 89 89 SW 13 8015 5698 798 Blue 5
7 PM Mon 86 86 SW 13 5733 4900 0 Blue 2
8 PM Mon 82 82 SW 13 3789 4900 0 Blue 0
9 PM Mon 78 78 S 8 3789 4900 0 Blue 0
10 PM Mon 75 75 S 8 3789 4900 0 Blue 0
11 PM Mon 72 72 S 8 3789 4900 0 Blue 0
12 Midnight Tue 69 69 S 5 3789 4900 0 Blue 0
1 AM Tue 67 67 S 5 3789 4900 0 Blue 0
2 AM Tue 66 66 S 5 3789 4900 0 Blue 0
3 AM Tue 63 63 SE 5 3789 4900 0 Blue 0
4 AM Tue 62 62 SE 5 3789 4900 0 Blue 0
5 AM Tue 60 60 SE 5 3789 4900 0 Blue 0
6 AM Tue 60 60 SE 2 3789 4900 0 Blue 0
7 AM Tue 59 59 SE 2 3789 4900 0 Blue 0
8 AM Tue 61 62 SE 2 3789 4900 0 Blue 0
9 AM Tue 68 70 SE 7 3789 4900 0 Blue 0
10 AM Tue 74 78 SE 7 3789 4900 0 Blue 0
11 AM Tue 78 84 SE 7 4250 4900 0 Blue 0
12 Noon Tue 81 87 SE 13 6542 4900 0 Blue 3
1 PM Tue 84 90 SE 13 9086 6491 1591 Blue 6
2 PM Tue 86 91 SE 13 16486 7235 2335 Blue 7
3 PM Tue 87 91 S 16 16486 7235 2335 Blue 7
4 PM Tue 89 91 S 16 16486 7235 2335 Blue 7
5 PM Tue 89 90 S 16 9086 6491 1591 Blue 6
6 PM Tue 88 88 S 16 7300 4900 0 Blue 4
7 PM Tue 85 85 S 16 4875 4900 0 Blue 1
8 PM Tue 82 82 S 16 3789 4900 0 Blue 0
9 PM Tue 78 78 S 10 3789 4900 0 Blue 0
10 PM Tue 76 76 S 10 3789 4900 0 Blue 0
11 PM Tue 73 73 S 10 3789 4900 0 Blue 0
12 Midnight Wed 71 71 S 8 3789 4900 0 Blue 0
1 AM Wed 69 69 S 8 3789 4900 0 Blue 0
2 AM Wed 68 68 S 8 3789 4900 0 Blue 0
3 AM Wed 66 66 SE 5 3789 4900 0 Blue 0
4 AM Wed 64 64 SE 5 3789 4900 0 Blue 0
5 AM Wed 63 63 SE 5 3789 4900 0 Blue 0
6 AM Wed 62 62 SE 5 3789 4900 0 Blue 0
7 AM Wed 62 62 SE 5 3789 4900 0 Blue 0
8 AM Wed 63 64 SE 5 3789 4900 0 Blue 0
9 AM Wed 69 71 SE 8 3789 4900 0 Blue 0
10 AM Wed 75 79 SE 8 3789 4900 0 Blue 0
11 AM Wed 78 83 SE 8 3917 4900 0 Blue 0
12 Noon Wed 81 87 S 14 6542 4900 0 Blue 3
1 PM Wed 84 90 S 14 9086 6491 1591 Blue 6
2 PM Wed 86 91 S 14 16486 7235 2335 Blue 7
3 PM Wed 86 90 S 15 9086 6491 1591 Blue 6
4 PM Wed 88 90 S 15 9086 6491 1591 Blue 6
5 PM Wed 88 89 S 15 8015 5698 798 Blue 5
6 PM Wed 87 87 S 15 6542 4900 0 Blue 3
7 PM Wed 84 84 S 15 4250 4900 0 Blue 0
8 PM Wed 82 82 S 15 3789 4900 0 Blue 0
9 PM Wed 77 77 S 10 3789 4900 0 Blue 0
10 PM Wed 75 75 S 10 3789 4900 0 Blue 0
11 PM Wed 72 72 S 10 3789 4900 0 Blue 0
12 Midnight Thu 70 70 S 6 3789 4900 0 Blue 0
1 AM Thu 68 68 S 6 3789 4900 0 Blue 0
2 AM Thu 67 67 S 6 3789 4900 0 Blue 0
3 AM Thu 65 65 S 5 3789 4900 0 Blue 0
4 AM Thu 64 64 S 5 3789 4900 0 Blue 0
5 AM Thu 62 62 S 5 3789 4900 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