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

Station:

KTUS

Date/Time:

18 SEP 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 Tue 73 73 N 7 3615 4900 0 Blue 0
7 AM Tue 73 73 N 5 3615 4900 0 Blue 0
8 AM Tue 73 73 E 3 3615 4900 0 Blue 0
9 AM Tue 80 82 SE 3 5748 4900 0 Blue 2
10 AM Tue 85 89 S 6 10150 7936 3036 Blue 9
11 AM Tue 88 93 S 8 12633 11149 6249 White 13
12 Noon Tue 90 96 S 10 13260 13260 8360 White 16
1 PM Tue 91 97 S 12 13470 13470 8570 White 17
2 PM Tue 92 97 SW 13 13470 13470 8570 White 17
3 PM Tue 92 96 SW 14 13260 13260 8360 White 16
4 PM Tue 93 95 SW 14 13051 13051 8151 White 15
5 PM Tue 93 93 SW 14 12633 11149 6249 White 13
6 PM Tue 92 92 SW 14 12423 9771 4871 White 12
7 PM Tue 89 89 SW 12 10150 7936 3036 Blue 9
8 PM Tue 86 86 SW 9 8016 6052 1152 Blue 6
9 PM Tue 82 82 SW 7 5748 4900 0 Blue 2
10 PM Tue 80 80 SW 7 3615 4900 0 Blue 0
11 PM Tue 78 78 W 6 3615 4900 0 Blue 0
12 Midnight Wed 77 77 W 6 3615 4900 0 Blue 0
1 AM Wed 76 76 SW 6 3615 4900 0 Blue 0
2 AM Wed 75 75 SW 6 3615 4900 0 Blue 0
3 AM Wed 74 74 SW 7 3615 4900 0 Blue 0
4 AM Wed 74 74 S 7 3615 4900 0 Blue 0
5 AM Wed 73 73 S 8 3615 4900 0 Blue 0
6 AM Wed 71 71 S 8 3615 4900 0 Blue 0
7 AM Wed 71 71 S 9 3615 4900 0 Blue 0
8 AM Wed 71 71 S 10 3615 4900 0 Blue 0
9 AM Wed 75 76 S 12 3615 4900 0 Blue 0
10 AM Wed 78 79 S 13 3615 4900 0 Blue 0
11 AM Wed 80 81 S 14 5423 4900 0 Blue 1
12 Noon Wed 81 82 S 14 5748 4900 0 Blue 2
1 PM Wed 82 84 S 14 6576 5410 510 Blue 4
2 PM Wed 82 84 S 14 6576 5410 510 Blue 4
3 PM Wed 83 84 S 13 6576 5410 510 Blue 4
4 PM Wed 83 84 S 12 6576 5410 510 Blue 4
5 PM Wed 83 83 S 10 6070 4900 0 Blue 3
6 PM Wed 82 82 S 9 5748 4900 0 Blue 2
7 PM Wed 80 80 S 9 3615 4900 0 Blue 0
8 PM Wed 77 77 S 8 3615 4900 0 Blue 0
9 PM Wed 75 75 S 7 3615 4900 0 Blue 0
10 PM Wed 73 73 SE 6 3615 4900 0 Blue 0
11 PM Wed 71 71 SE 5 3615 4900 0 Blue 0
12 Midnight Thu 71 71 SE 3 3615 4900 0 Blue 0
1 AM Thu 70 70 E 3 3615 4900 0 Blue 0
2 AM Thu 69 69 E 3 3615 4900 0 Blue 0
3 AM Thu 69 69 NE 2 3615 4900 0 Blue 0
4 AM Thu 68 68 N 2 3615 4900 0 Blue 0
5 AM Thu 67 67 N 2 3615 4900 0 Blue 0
6 AM Thu 66 66 N 2 3615 4900 0 Blue 0
7 AM Thu 66 66 N 1 3615 4900 0 Blue 0
8 AM Thu 66 66 NW 1 3615 4900 0 Blue 0
9 AM Thu 72 74 NW 1 3615 4900 0 Blue 0
10 AM Thu 78 81 NW 0 5423 4900 0 Blue 1
11 AM Thu 80 84 NW 1 6576 5410 510 Blue 4
12 Noon Thu 82 87 NW 1 8659 6520 1620 Blue 7
1 PM Thu 83 88 NW 2 9330 7247 2347 Blue 8
2 PM Thu 84 88 NW 5 9330 7247 2347 Blue 8
3 PM Thu 84 87 W 7 8659 6520 1620 Blue 7
4 PM Thu 85 87 W 8 8659 6520 1620 Blue 7
5 PM Thu 85 85 W 10 7316 5732 832 Blue 5
6 PM Thu 84 84 W 12 6576 5410 510 Blue 4
7 PM Thu 82 82 W 12 5748 4900 0 Blue 2
8 PM Thu 78 78 W 12 3615 4900 0 Blue 0
9 PM Thu 75 75 W 10 3615 4900 0 Blue 0
10 PM Thu 73 73 W 9 3615 4900 0 Blue 0
11 PM Thu 71 71 NW 8 3615 4900 0 Blue 0
12 Midnight Fri 71 71 NW 7 3615 4900 0 Blue 0
1 AM Fri 70 70 NW 7 3615 4900 0 Blue 0
2 AM Fri 69 69 NW 6 3615 4900 0 Blue 0
3 AM Fri 68 68 NW 6 3615 4900 0 Blue 0
4 AM Fri 67 67 NW 5 3615 4900 0 Blue 0
5 AM Fri 67 67 NW 5 3615 4900 0 Blue 0
6 AM Fri 65 65 N 5 3615 4900 0 Blue 0
7 AM Fri 65 65 NW 5 3615 4900 0 Blue 0
8 AM Fri 65 65 NW 5 3615 4900 0 Blue 0
9 AM Fri 72 74 W 5 3615 4900 0 Blue 0
10 AM Fri 77 80 W 5 3615 4900 0 Blue 0
11 AM Fri 80 84 SW 5 6576 5410 510 Blue 4
12 Noon Fri 82 87 SW 5 8659 6520 1620 Blue 7
1 PM Fri 83 88 SW 6 9330 7247 2347 Blue 8
2 PM Fri 84 88 SW 6 9330 7247 2347 Blue 8
3 PM Fri 84 87 SW 7 8659 6520 1620 Blue 7
4 PM Fri 85 87 SW 8 8659 6520 1620 Blue 7
5 PM Fri 85 85 W 9 7316 5732 832 Blue 5
6 PM Fri 84 84 W 9 6576 5410 510 Blue 4
7 PM Fri 82 82 W 9 5748 4900 0 Blue 2
8 PM Fri 79 79 W 9 3615 4900 0 Blue 0
9 PM Fri 76 76 W 8 3615 4900 0 Blue 0
10 PM Fri 73 73 NW 8 3615 4900 0 Blue 0
11 PM Fri 72 72 NW 7 3615 4900 0 Blue 0
12 Midnight Sat 71 71 NW 6 3615 4900 0 Blue 0
1 AM Sat 70 70 NW 6 3615 4900 0 Blue 0
2 AM Sat 70 70 NW 6 3615 4900 0 Blue 0
3 AM Sat 69 69 N 6 3615 4900 0 Blue 0
4 AM Sat 68 68 N 6 3615 4900 0 Blue 0
5 AM Sat 67 67 N 6 3615 4900 0 Blue 0
6 AM Sat 66 66 N 6 3615 4900 0 Blue 0
7 AM Sat 66 66 N 6 3615 4900 0 Blue 0
8 AM Sat 66 66 NE 5 3615 4900 0 Blue 0
9 AM Sat 73 75 E 5 3615 4900 0 Blue 0
10 AM Sat 78 81 SE 3 5423 4900 0 Blue 1
11 AM Sat 81 86 SE 3 8016 6052 1152 Blue 6
12 Noon Sat 83 88 S 3 9330 7247 2347 Blue 8
1 PM Sat 84 89 S 3 10150 7936 3036 Blue 9
2 PM Sat 85 90 S 3 11319 8580 3680 Blue 10
3 PM Sat 85 88 S 3 9330 7247 2347 Blue 8
4 PM Sat 86 88 SW 3 9330 7247 2347 Blue 8
5 PM Sat 86 86 SW 5 8016 6052 1152 Blue 6
6 PM Sat 85 85 SW 5 7316 5732 832 Blue 5
7 PM Sat 83 83 SW 5 6070 4900 0 Blue 3
8 PM Sat 80 80 W 3 3615 4900 0 Blue 0
9 PM Sat 77 77 W 2 3615 4900 0 Blue 0
10 PM Sat 74 74 W 1 3615 4900 0 Blue 0
11 PM Sat 73 73 W 1 3615 4900 0 Blue 0
12 Midnight Sun 72 72 W 1 3615 4900 0 Blue 0
1 AM Sun 71 71 W 1 3615 4900 0 Blue 0
2 AM Sun 71 71 NW 2 3615 4900 0 Blue 0
3 AM Sun 70 70 NW 2 3615 4900 0 Blue 0
4 AM Sun 69 69 N 3 3615 4900 0 Blue 0
5 AM Sun 68 68 N 5 3615 4900 0 Blue 0
6 AM Sun 67 67 N 5 3615 4900 0 Blue 0
7 AM Sun 67 67 NE 6 3615 4900 0 Blue 0
8 AM Sun 67 67 NE 5 3615 4900 0 Blue 0
9 AM Sun 74 76 E 5 3615 4900 0 Blue 0
10 AM Sun 80 83 SE 5 6070 4900 0 Blue 3
11 AM Sun 83 88 S 5 9330 7247 2347 Blue 8
12 Noon Sun 85 90 S 5 11319 8580 3680 Blue 10
1 PM Sun 86 91 S 5 12213 9262 4362 White 11
2 PM Sun 87 92 S 5 12423 9771 4871 White 12
3 PM Sun 87 90 SW 6 11319 8580 3680 Blue 10
4 PM Sun 88 90 SW 6 11319 8580 3680 Blue 10
5 PM Sun 88 88 SW 6 9330 7247 2347 Blue 8
6 PM Sun 87 87 SW 6 8659 6520 1620 Blue 7
7 PM Sun 84 84 W 5 6576 5410 510 Blue 4
8 PM Sun 81 81 W 5 5423 4900 0 Blue 1
9 PM Sun 78 78 W 3 3615 4900 0 Blue 0
10 PM Sun 75 75 NW 2 3615 4900 0 Blue 0
11 PM Sun 74 74 NW 1 3615 4900 0 Blue 0
12 Midnight Mon 73 73 N 1 3615 4900 0 Blue 0
1 AM Mon 72 72 N 1 3615 4900 0 Blue 0
2 AM Mon 71 71 N 2 3615 4900 0 Blue 0
3 AM Mon 70 70 N 2 3615 4900 0 Blue 0
4 AM Mon 69 69 N 3 3615 4900 0 Blue 0
5 AM Mon 69 69 N 5 3615 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