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

Station:

KTUS

Date/Time:

27 MAY 2018

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 Sun 58 58 N 3 3612 4900 0 Blue 0
7 AM Sun 60 61 NE 3 3612 4900 0 Blue 0
8 AM Sun 64 66 E 3 4989 4900 0 Blue 1
9 AM Sun 67 71 E 3 6794 5484 584 Blue 6
10 AM Sun 71 77 S 3 8688 7662 2762 Blue 12
11 AM Sun 74 82 S 7 9991 9253 4353 Blue 17
12 Noon Sun 76 85 SW 9 10635 9953 5053 Blue 20
1 PM Sun 77 85 SW 10 10635 9953 5053 Blue 20
2 PM Sun 78 85 SW 12 10635 9953 5053 Blue 20
3 PM Sun 79 85 SW 12 10635 9953 5053 Blue 20
4 PM Sun 80 84 SW 12 10417 9751 4851 Blue 19
5 PM Sun 81 83 SW 12 10197 9548 4648 Blue 18
6 PM Sun 81 81 SW 10 9788 8950 4050 Blue 16
7 PM Sun 80 80 SW 9 9583 8644 3744 Blue 15
8 PM Sun 78 78 W 8 8997 8003 3103 Blue 13
9 PM Sun 76 76 W 7 8377 7318 2418 Blue 11
10 PM Sun 73 73 W 6 7353 6520 1620 Blue 8
11 PM Sun 72 72 NW 6 7047 6040 1140 Blue 7
12 Midnight Mon 70 70 NW 5 6539 5167 267 Blue 5
1 AM Mon 69 69 N 5 6074 4984 84 Blue 4
2 AM Mon 67 67 N 3 5173 4900 0 Blue 2
3 AM Mon 66 66 N 3 4989 4900 0 Blue 1
4 AM Mon 64 64 N 3 4034 4900 0 Blue 0
5 AM Mon 63 63 N 3 3612 4900 0 Blue 0
6 AM Mon 63 63 N 3 3612 4900 0 Blue 0
7 AM Mon 66 67 NE 3 5173 4900 0 Blue 2
8 AM Mon 69 71 NE 2 6794 5484 584 Blue 6
9 AM Mon 73 77 E 2 8688 7662 2762 Blue 12
10 AM Mon 76 82 SW 3 9991 9253 4353 Blue 17
11 AM Mon 79 87 SW 6 11514 10372 5472 Blue 22
12 Noon Mon 80 89 SW 9 12680 10807 5907 Blue 24
1 PM Mon 82 91 SW 10 13762 11959 7059 Blue 26
2 PM Mon 83 91 W 12 13762 11959 7059 Blue 26
3 PM Mon 85 91 W 14 13762 11959 7059 Blue 26
4 PM Mon 86 90 W 14 13230 11370 6470 Blue 25
5 PM Mon 87 89 W 14 12680 10807 5907 Blue 24
6 PM Mon 87 87 W 14 11514 10372 5472 Blue 22
7 PM Mon 85 85 W 13 10635 9953 5053 Blue 20
8 PM Mon 82 82 W 12 9991 9253 4353 Blue 17
9 PM Mon 79 79 W 10 9303 8335 3435 Blue 14
10 PM Mon 77 77 W 9 8688 7662 2762 Blue 12
11 PM Mon 76 76 W 8 8377 7318 2418 Blue 11
12 Midnight Tue 74 74 NW 7 7701 6773 1873 Blue 9
1 AM Tue 73 73 NW 6 7353 6520 1620 Blue 8
2 AM Tue 72 72 NW 6 7047 6040 1140 Blue 7
3 AM Tue 71 71 N 6 6794 5484 584 Blue 6
4 AM Tue 69 69 N 6 6074 4984 84 Blue 4
5 AM Tue 68 68 N 5 5508 4900 0 Blue 3
6 AM Tue 68 68 N 5 5508 4900 0 Blue 3
7 AM Tue 70 70 NE 6 6539 5167 267 Blue 5
8 AM Tue 74 76 N 5 8377 7318 2418 Blue 11
9 AM Tue 78 82 N 5 9991 9253 4353 Blue 17
10 AM Tue 81 87 NW 3 11514 10372 5472 Blue 22
11 AM Tue 84 91 W 5 13762 11959 7059 Blue 26
12 Noon Tue 85 93 W 6 14778 13070 8170 Blue 28
1 PM Tue 87 95 W 7 16296 14109 9209 Blue 30
2 PM Tue 88 95 W 9 16296 14109 9209 Blue 30
3 PM Tue 89 94 W 9 15264 13598 8698 Blue 29
4 PM Tue 90 93 W 10 14778 13070 8170 Blue 28
5 PM Tue 91 92 SW 13 14278 12525 7625 Blue 27
6 PM Tue 91 91 SW 13 13762 11959 7059 Blue 26
7 PM Tue 90 90 SW 12 13230 11370 6470 Blue 25
8 PM Tue 87 87 SW 10 11514 10372 5472 Blue 22
9 PM Tue 85 85 W 10 10635 9953 5053 Blue 20
10 PM Tue 83 83 W 9 10197 9548 4648 Blue 18
11 PM Tue 81 81 W 8 9788 8950 4050 Blue 16
12 Midnight Wed 79 79 W 8 9303 8335 3435 Blue 14
1 AM Wed 78 78 SW 7 8997 8003 3103 Blue 13
2 AM Wed 76 76 SW 7 8377 7318 2418 Blue 11
3 AM Wed 74 74 SW 7 7701 6773 1873 Blue 9
4 AM Wed 72 72 SW 7 7047 6040 1140 Blue 7
5 AM Wed 70 70 SW 7 6539 5167 267 Blue 5
6 AM Wed 70 70 SW 5 6539 5167 267 Blue 5
7 AM Wed 72 72 S 6 7047 6040 1140 Blue 7
8 AM Wed 75 77 S 7 8688 7662 2762 Blue 12
9 AM Wed 78 82 S 8 9991 9253 4353 Blue 17
10 AM Wed 80 86 S 9 10892 10155 5255 Blue 21
11 AM Wed 82 89 S 10 12680 10807 5907 Blue 24
12 Noon Wed 84 92 S 12 14278 12525 7625 Blue 27
1 PM Wed 85 93 S 14 14778 13070 8170 Blue 28
2 PM Wed 86 93 S 15 14778 13070 8170 Blue 28
3 PM Wed 88 94 S 16 15264 13598 8698 Blue 29
4 PM Wed 89 93 S 17 14778 13070 8170 Blue 28
5 PM Wed 89 91 S 17 13762 11959 7059 Blue 26
6 PM Wed 88 88 S 17 12109 10590 5690 Blue 23
7 PM Wed 87 87 S 16 11514 10372 5472 Blue 22
8 PM Wed 84 84 S 15 10417 9751 4851 Blue 19
9 PM Wed 82 82 S 14 9991 9253 4353 Blue 17
10 PM Wed 79 79 S 12 9303 8335 3435 Blue 14
11 PM Wed 77 77 S 10 8688 7662 2762 Blue 12
12 Midnight Thu 76 76 S 9 8377 7318 2418 Blue 11
1 AM Thu 74 74 S 9 7701 6773 1873 Blue 9
2 AM Thu 73 73 S 9 7353 6520 1620 Blue 8
3 AM Thu 71 71 S 10 6794 5484 584 Blue 6
4 AM Thu 69 69 S 10 6074 4984 84 Blue 4
5 AM Thu 67 67 SE 12 5173 4900 0 Blue 2
6 AM Thu 67 67 SE 13 5173 4900 0 Blue 2
7 AM Thu 68 68 SE 13 5508 4900 0 Blue 3
8 AM Thu 70 72 SE 14 7047 6040 1140 Blue 7
9 AM Thu 72 76 SE 15 8377 7318 2418 Blue 11
10 AM Thu 75 80 S 15 9583 8644 3744 Blue 15
11 AM Thu 76 83 S 16 10197 9548 4648 Blue 18
12 Noon Thu 78 85 S 16 10635 9953 5053 Blue 20
1 PM Thu 80 87 S 17 11514 10372 5472 Blue 22
2 PM Thu 81 87 S 18 11514 10372 5472 Blue 22
3 PM Thu 83 88 S 18 12109 10590 5690 Blue 23
4 PM Thu 84 87 S 20 11514 10372 5472 Blue 22
5 PM Thu 84 85 S 20 10635 9953 5053 Blue 20
6 PM Thu 83 83 S 18 10197 9548 4648 Blue 18
7 PM Thu 82 82 S 18 9991 9253 4353 Blue 17
8 PM Thu 80 80 S 16 9583 8644 3744 Blue 15
9 PM Thu 77 77 S 15 8688 7662 2762 Blue 12
10 PM Thu 76 76 S 13 8377 7318 2418 Blue 11
11 PM Thu 74 74 S 10 7701 6773 1873 Blue 9
12 Midnight Fri 73 73 S 9 7353 6520 1620 Blue 8
1 AM Fri 72 72 S 8 7047 6040 1140 Blue 7
2 AM Fri 70 70 S 8 6539 5167 267 Blue 5
3 AM Fri 69 69 S 7 6074 4984 84 Blue 4
4 AM Fri 67 67 SE 7 5173 4900 0 Blue 2
5 AM Fri 65 65 SE 7 4672 4900 0 Blue 0
6 AM Fri 65 65 SE 7 4672 4900 0 Blue 0
7 AM Fri 67 67 SE 8 5173 4900 0 Blue 2
8 AM Fri 70 72 SE 8 7047 6040 1140 Blue 7
9 AM Fri 73 77 SE 9 8688 7662 2762 Blue 12
10 AM Fri 75 81 SE 9 9788 8950 4050 Blue 16
11 AM Fri 77 84 S 9 10417 9751 4851 Blue 19
12 Noon Fri 79 88 S 10 12109 10590 5690 Blue 23
1 PM Fri 81 89 S 12 12680 10807 5907 Blue 24
2 PM Fri 83 90 S 14 13230 11370 6470 Blue 25
3 PM Fri 84 90 S 15 13230 11370 6470 Blue 25
4 PM Fri 86 90 S 15 13230 11370 6470 Blue 25
5 PM Fri 86 88 SW 14 12109 10590 5690 Blue 23
6 PM Fri 85 85 SW 13 10635 9953 5053 Blue 20
7 PM Fri 83 83 SW 13 10197 9548 4648 Blue 18
8 PM Fri 81 81 SW 12 9788 8950 4050 Blue 16
9 PM Fri 78 78 SW 10 8997 8003 3103 Blue 13
10 PM Fri 75 75 W 8 8045 7024 2124 Blue 10
11 PM Fri 73 73 W 7 7353 6520 1620 Blue 8
12 Midnight Sat 72 72 W 5 7047 6040 1140 Blue 7
1 AM Sat 71 71 W 3 6794 5484 584 Blue 6
2 AM Sat 69 69 NW 5 6074 4984 84 Blue 4
3 AM Sat 68 68 NW 5 5508 4900 0 Blue 3
4 AM Sat 66 66 N 6 4989 4900 0 Blue 1
5 AM Sat 64 64 N 7 4034 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